毕设-外文翻译

A Design and Implementation of Active NetworkSocket ProgrammingK.L. Eddie Law, Roy LeungThe Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoToronto, Canadaeddie@, roy.leung@utoronto.caAbstract—The concept of programmable nodes and active networks introduces programmability into communication networks. Code and data can be sent and modified on their ways to destinations. Recently, various research groups have designed and implemented their own design platforms. Each design has its own benefits and drawbacks. Moreover, there exists an interoperability problem among platforms. As a result, we introduce a concept that is similar to the network socket programming. We intentionally establish a set of simple interfaces for programming active applications. This set of interfaces, known as Active Network Socket Programming (ANSP), will be working on top of all other execution environments in future. Therefore, the ANSP offers a concept that is similar to “write once, run everywhere.” It is an open programming model that active applications can work on all execution environments. It solves the heterogeneity within active networks. This is especially useful when active applications need to access all regions within a heterogeneous network to deploy special service at critical points or to monitor the performance of the entire networks. Instead of introducing a new platform, our approach provides a thin, transparent layer on top of existing environments that can be easily installed for all active applications.Keywords-active networks; application programming interface; active network socket programming;I. I NTRODUCTIONIn 1990, Clark and Tennenhouse [1] proposed a design framework for introducing new network protocols for the Internet. Since the publication of that position paper, active network design framework [2, 3, 10] has slowly taken shape in the late 1990s. The active network paradigm allows program code and data to be delivered simultaneously on the Internet. Moreover, they may get executed and modified on their ways to their destinations. At the moment, there is a global active network backbone, the ABone, for experiments on active networks. Apart from the immaturity of the executing platform, the primary hindrance on the deployment of active networks on the Internet is more on the commercially related issues. For example, a vendor may hesitate to allow network routers to run some unknown programs that may affect their expected routing performance. As a result, alternatives were proposed to allow active network concept to operate on the Internet, such as the application layer active networking (ALAN) project [4] from the European research community. In the ALAN project, there are active server systems located at different places in the networks and active applications are allowed to run in these servers at the application layer. Another potential approach from the network service provider is to offer active network service as the premium service class in the networks. This service class should provide the best Quality of Service (QoS), and allow the access of computing facility in routers. With this approach, the network service providers can create a new source of income.The research in active networks has been progressing steadily. Since active networks introduce programmability on the Internet, appropriate executing platforms for the active applications to execute should be established. These operating platforms are known as execution environments (EEs) and a few of them have been created, e.g., the Active Signaling Protocol (ASP) [12] and the Active Network Transport System (ANTS) [11]. Hence, different active applications can be implemented to test the active networking concept.With these EEs, some experiments have been carried out to examine the active network concept, for example, the mobile networks [5], web proxies [6], and multicast routers [7]. Active networks introduce a lot of program flexibility and extensibility in networks. Several research groups have proposed various designs of execution environments to offer network computation within routers. Their performance and potential benefits to existing infrastructure are being evaluated [8, 9]. Unfortunately, they seldom concern the interoperability problems when the active networks consist of multiple execution environments. For example, there are three EEs in ABone. Active applications written for one particular EE cannot be operated on other platforms. This introduces another problem of resources partitioning for different EEs to operate. Moreover, there are always some critical network applications that need to run under all network routers, such as collecting information and deploying service at critical points to monitor the networks.In this paper, a framework known as Active Network Socket Programming (ANSP) model is proposed to work with all EEs. It offers the following primary objectives.• One single programming interface is introduced for writing active applications.• Since ANSP offers the programming interface, the design of EE can be made independent of the ANSP.This enables a transparency in developing andenhancing future execution environments.• ANSP addresses the interoperability issues among different execution environments.• Through the design of ANSP, the pros and cons of different EEs will be gained. This may help design abetter EE with improved performance in future.The primary objective of the ANSP is to enable all active applications that are written in ANSP can operate in the ABone testbed . While the proposed ANSP framework is essential in unifying the network environments, we believe that the availability of different environments is beneficial in the development of a better execution environment in future. ANSP is not intended to replace all existing environments, but to enable the studies of new network services which are orthogonal to the designs of execution environments. Therefore, ANSP is designed to be a thin and transparent layer on top of all execution environments. Currently, its deployment relies on automatic code loading with the underlying environments. As a result, the deployment of ANSP at a router is optional and does not require any change to the execution environments.II. D ESIGN I SSUES ON ANSPThe ANSP unifies existing programming interfaces among all EEs. Conceptually, the design of ANSP is similar to the middleware design that offers proper translation mechanisms to different EEs. The provisioning of a unified interface is only one part of the whole ANSP platform. There are many other issues that need to be considered. Apart from translating a set of programming interfaces to other executable calls in different EEs, there are other design issues that should be covered, e.g., • a unified thread library handles thread operations regardless of the thread libraries used in the EEs;• a global soft-store allows information sharing among capsules that may execute over different environmentsat a given router;• a unified addressing scheme used across different environments; more importantly, a routing informationexchange mechanism should be designed across EEs toobtain a global view of the unified networks;• a programming model that should be independent to any programming languages in active networks;• and finally, a translation mechanism to hide the heterogeneity of capsule header structures.A. Heterogeneity in programming modelEach execution environment provides various abstractions for its services and resources in the form of program calls. The model consists of a set of well-defined components, each of them has its own programming interfaces. For the abstractions, capsule-based programming model [10] is the most popular design in active networks. It is used in ANTS [11] and ASP [12], and they are being supported in ABone. Although they are developed based on the same capsule model, their respective components and interfaces are different. Therefore, programs written in one EE cannot run in anther EE. The conceptual views of the programming models in ANTS and ASP are shown in Figure 1.There are three distinct components in ANTS: application, capsule, and execution environment. There exist user interfaces for the active applications at only the source and destination routers. Then the users can specify their customized actions to the networks. According to the program function, the applications send one or more capsules to carry out the operations. Both applications and capsules operate on top of an execution environment that exports an interface to its internal programming resources. Capsule executes its program at each router it has visited. When it arrives at its destination, the application at destination may either reply it with another capsule or presents this arrival event to the user. One drawback with ANTS is that it only allows “bootstrap” application.Figure 1. Programming Models in ASP and ANTS.In contrast, ASP does not limit its users to run “bootstrap” applications. Its program interfaces are different from ANTS, but there are also has three components in ASP: application client, environment, and AAContext. The application client can run on active or non-active host. It can start an active application by simply sending a request message to the EE. The client presents information to users and allows its users to trigger actions at a nearby active router. AAContext is the core of the network service and its specification is divided into two parts. One part specifies its actions at its source and destination routers. Its role is similar to that of the application in ANTS, except that it does not provide a direct interface with the user. The other part defines its actions when it runs inside the active networks and it is similar to the functional behaviors of a capsule in ANTS.In order to deal with the heterogeneity of these two models, ANSP needs to introduce a new set of programming interfaces and map its interfaces and execution model to those within the routers’ EEs.B. Unified Thread LibraryEach execution environment must ensure the isolation of instance executions, so they do not affect each other or accessThe authors appreciate the Nortel Institute for Telecommunications (NIT) at the University of Toronto to allow them to access the computing facilitiesothers’ information. There are various ways to enforce the access control. One simple way is to have one virtual machine for one instance of active applications. This relies on the security design in the virtual machines to isolate services. ANTS is one example that is using this method. Nevertheless, the use of multiple virtual machines requires relatively large amount of resources and may be inefficient in some cases. Therefore, certain environments, such as ASP, allow network services to run within a virtual machine but restrict the use of their services to a limited set of libraries in their packages. For instance, ASP provides its thread library to enforce access control. Because of the differences in these types of thread mechanism, ANSP devises a new thread library to allow uniform accesses to different thread mechanisms.C. Soft-StoreSoft-store allows capsule to insert and retrieve information at a router, thus allowing more than one capsules to exchange information within a network. However, problem arises when a network service can execute under different environments within a router. The problem occurs especially when a network service inserts its soft-store information in one environment and retrieves its data at a later time in another environment at the same router. Due to the fact that execution environments are not allowed to exchange information, the network service cannot retrieve its previous data. Therefore, our ANSP framework needs to take into account of this problem and provides soft-store mechanism that allows universal access of its data at each router.D. Global View of a Unified NetworkWhen an active application is written with ANSP, it can execute on different environment seamlessly. The previously smaller and partitioned networks based on different EEs can now be merging into one large active network. It is then necessary to advise the network topology across the networks. However, different execution environments have different addressing schemes and proprietary routing protocols. In order to merge these partitions together, ANSP must provide a new unified addressing scheme. This new scheme should be interpretable by any environments through appropriate translations with the ANSP. Upon defining the new addressing scheme, a new routing protocol should be designed to operate among environments to exchange topology information. This allows each environment in a network to have a complete view of its network topology.E. Language-Independent ModelExecution environment can be programmed in any programming language. One of the most commonly used languages is Java [13] due to its dynamic code loading capability. In fact, both ANTS and ASP are developed in Java. Nevertheless, the active network architecture shown in Figure 2 does not restrict the use of additional environments that are developed in other languages. For instance, the active network daemon, anted, in Abone provides a workspace to execute multiple execution environments within a router. PLAN, for example, is implemented in Ocaml that will be deployable on ABone in future. Although the current active network is designed to deploy multiple environments that can be in any programming languages, there lacks the tool to allow active applications to run seamlessly upon these environments. Hence, one of the issues that ANSP needs to address is to design a programming model that can work with different programming languages. Although our current prototype only considers ANTS and ASP in its design, PLAN will be the next target to address the programming language issue and to improve the design of ANSP.Figure 2. ANSP Framework Model.F. Heterogeneity of Capsule Header StructureThe structures of the capsule headers are different in different EEs. They carries capsule-related information, for example, the capsule types, sources and destinations. This information is important when certain decision needs to be made within its target environment. A unified model should allow its program code to be executed on different environments. However, the capsule header prevents different environments to interpret its information successfully. Therefore, ANSP should carry out appropriate translation to the header information before the target environment receives this capsule.III. ANSP P ROGRAMMING M ODELWe have outlined the design issues encountered with the ANSP. In the following, the design of the programming model in ANSP will be discussed. This proposed framework provides a set of unified programming interfaces that allows active applications to work on all execution environments. The framework is shown in Figure 2. It is composed of two layers integrated within the active network architecture. These two layers can operate independently without the other layer. The upper layer provides a unified programming model to active applications. The lower layer provides appropriate translation procedure to the ANSP applications when it is processed by different environments. This service is necessary because each environment has its own header definition.The ANSP framework provides a set of programming calls which are abstractions of ANSP services and resources. A capsule-based model is used for ANSP, and it is currently extended to map to other capsule-based models used in ANTSand ASP. The mapping possibility to other models remains as our future works. Hence, the mapping technique in ANSP allows any ANSP applications to access the same programming resources in different environments through a single set of interfaces. The mapping has to be done in a consistent and transparent manner. Therefore, the ANSP appears as an execution environment that provides a complete set of functionalities to active applications. While in fact, it is an overlay structure that makes use of the services provided from the underlying environments. In the following, the high-level functional descriptions of the ANSP model are described. Then, the implementations will be discussed. The ANSP programming model is based upon the interactions between four components: application client , application stub , capsule , and active service base.Figure 3. Information Flow with the ANSP.•Application Client : In a typical scenario, an active application requires some means to present information to its users, e.g., the state of the networks. A graphical user interface (GUI) is designed to operate with the application client if the ANSP runs on a non-active host.•Application Stub : When an application starts, it activates the application client to create a new instance of application stub at its near-by active node. There are two responsibilities for the application stub. One of them is to receive users’ instructions from the application client. Another one is to receive incoming capsules from networks and to perform appropriate actions. Typically, there are two types of actions, thatare, to reply or relay in capsules through the networks, or to notify the users regarding the incoming capsule. •Capsule : An active application may contain several capsule types. Each of them carries program code (also referred to as forwarding routine). Since the application defines a protocol to specify the interactions among capsules as well as the application stubs. Every capsule executes its forwarding routine at each router it visits along the path between the source and destination.•Active Service Base : An active service base is designed to export routers’ environments’ services and execute program calls from application stubs and capsules from different EEs. The base is loaded automatically at each router whenever a capsule arrives.The interactions among components within ANSP are shown in Figure 3. The designs of some key components in the ANSP will be discussed in the following subsections. A. Capsule (ANSPCapsule)ANSPXdr decode () ANSPXdr encode () int length ()Boolean execute ()New types of capsule are created by extending the abstract class ANSPCapsule . New extensions are required to define their own forwarding routines as well as their serialization procedures. These methods are indicated below:The execution of a capsule in ANSP is listed below. It is similar to the process in ANTS.1. A capsule is in serial binary representation before it issent to the network. When an active router receives a byte sequence, it invokes decode() to convert the sequence into a capsule. 2. The router invokes the forwarding routine of thecapsule, execute(). 3. When the capsule has finished its job and forwardsitself to its next hop by calling send(), this call implicitly invokes encode() to convert the capsule into a new serial byte representation. length() isused inside the call of encode() to determine the length of the resulting byte sequence. ANSP provides a XDR library called ANSPXdr to ease the jobs of encoding and decoding.B. Active Service Base (ANSPBase)In an active node, the Active Service Base provides a unified interface to export the available resources in EEs for the rest of the ANSP components. The services may include thread management, node query, and soft-store operation, as shown in Table 1.TABLE I. ACTIVE SERVICE BASE FUNCTION CALLSFunction Definition Descriptionboolean send (Capsule, Address) Transmit a capsule towards its destination using the routing table of theunderlying environment.ANSPAddress getLocalHost () Return address of the local host as an ANSPAddress structure. This isuseful when a capsule wants to check its current location.boolean isLocal (ANSPAddress) Return true if its input argument matches the local host’s address andreturn false otherwise.createThread () Create a new thread that is a class ofANSPThreadInterface (discussed later in Section VIA “Unified Thread Abstraction”).putSStore (key, Object) Object getSStore (key) removeSStore (key)The soft-store operations are provided by putSStore(), getSSTore(), and removeSStore(), and they put, retrieve, and remove data respectively. forName (PathName) Supported in ANSP to retrieve a classobject corresponding to the given path name in its argument. This code retrieval may rely on the code loading mechanism in the environment whennecessary.C. Application Client (ANSPClient)boolean start (args[])boolean start (args[],runningEEs) boolean start (args[],startClient)boolean start (args[],startClient, runningEE)Application Client is an interface between users and the nearby active source router. It does the following responsibilities.1. Code registration: It may be necessary to specify thelocation and name of the application code in some execution environments, e.g., ANTS. 2. Application initialization: It includes selecting anexecution environment to execute the application among those are available at the source router. Each active application can create an application client instance by extending the abstract class, ANSPClient . The extension inherits a method, start(), to automatically handle both the registration and initialization processes. All overloaded versions of start() accept a list of arguments, args , that are passed to the application stub during its initialization. An optional argument called runningEEs allows an application client to select a particular set of environment variables, specified by a list of standardized numerical environment ID, the ANEP ID, to perform code registration. If this argument is not specified, the default setting can only include ANTS and ASP. D. Application Stub (ANSPApplication)receive (ANSPCapsule)Application stubs reside at the source and destination routers to initialize the ANSP application after the application clients complete the initialization and registration processes. It is responsible for receiving and serving capsules from the networks as well as actions requested from the clients. A new instance is created by extending the application client abstract class, ANSPApplication . This extension includes the definition of a handling routine called receive(), which is invoked when a stub receives a new capsule.IV. ANSP E XAMPLE : T RACE -R OUTEA testbed has been created to verify the design correctnessof ANSP in heterogeneous environments. There are three types of router setting on this testbed:1. Router that contains ANTS and a ANSP daemonrunning on behalf of ASP; 2. Router that contains ASP and a ANSP daemon thatruns on behalf of ANTS; 3. Router that contains both ASP and ANTS.The prototype is written in Java [11] with a traceroute testing program. The program records the execution environments of all intermediate routers that it has visited between the source and destination. It also measures the RTT between them. Figure 4 shows the GUI from the application client, and it finds three execution environments along the path: ASP, ANTS, and ASP. The execution sequence of the traceroute program is shown in Figure 5.Figure 4. The GUI for the TRACEROUTE Program.The TraceCapsule program code is created byextending the ANSPCapsule abstract class. When execute() starts, it checks the Boolean value of returning to determine if it is returning from the destination. It is set to true if TraceCapsule is traveling back to the source router; otherwise it is false . When traveling towards the destination, TraceCapsule keeps track of the environments and addresses of the routers it has visited in two arrays, path and trace , respectively. When it arrives at a new router, it calls addHop() to append the router address and its environment to these two arrays. When it finally arrives at the destination, it sets returning to false and forwards itself back to the source by calling send().When it returns to source, it invokes deliverToApp() to deliver itself to the application stub that has been running at the source. TraceCapsule carries information in its data field through the networks by executing encode() and decode(), which encapsulates and de-capsulates its data using External Data Representation (XDR) respectively. The syntax of ANSP XDR follows the syntax of XDR library from ANTS. length() in TraceCapsule returns the data length, or it can be calculated by using the primitive types in the XDRlibrary.Figure 5. Flow of the TRACEROUTE Capsules.V. C ONCLUSIONSIn this paper, we present a new unified layered architecture for active networks. The new model is known as Active Network Socket Programming (ANSP). It allows each active application to be written once and run on multiple environments in active networks. Our experiments successfully verify the design of ANSP architecture, and it has been successfully deployed to work harmoniously with ANTS and ASP without making any changes to their architectures. In fact, the unified programming interface layer is light-weighted and can be dynamically deployable upon request.R EFERENCES[1] D.D. Clark, D.L. Tennenhouse, “Architectural Considerations for a NewGeneration of Protocols,” in Proc. ACM Sigcomm’90, pp.200-208, 1990. [2] D. Tennenhouse, J. M. Smith, W. D. Sicoskie, D. J. Wetherall, and G. J.Minden, “A survey of active network research,” IEEE Communications Magazine , pp. 80-86, Jan 1997.[3] D. Wetherall, U. Legedza, and J. Guttag, “Introducing new internetservices: Why and how,” IEEE Network Magazine, July/August 1998. [4] M. Fry, A. Ghosh, “Application Layer Active Networking,” in ComputerNetworks , Vol.31, No.7, pp.655-667, 1999.[5] K. W. Chin, “An Investigation into The Application of Active Networksto Mobile Computing Environments”, Curtin University of Technology, March 2000.[6] S. Bhattacharjee, K. L. Calvert, and E. W. Zegura, “Self OrganizingWide-Area Network Caches”, Proc. IEEE INFOCOM ’98, San Francisco, CA, 29 March-2 April 1998.[7] L. H. Leman, S. J. Garland, and D. L. Tennenhouse, “Active ReliableMulticast”, Proc. IEEE INFOCOM ’98, San Francisco, CA, 29 March-2 April 1998.[8] D. Descasper, G. Parulkar, B. Plattner, “A Scalable, High PerformanceActive Network Node”, In IEEE Network, January/February 1999.[9] E. L. Nygren, S. J. Garland, and M. F. Kaashoek, “PAN: a high-performance active network node supporting multiple mobile code system”, In the Proceedings of the 2nd IEEE Conference on Open Architectures and Network Programming (OpenArch ’99), March 1999. [10] D. L. Tennenhouse, and D. J. Wetherall. “Towards an Active NetworkArchitecture”, In Proceeding of Multimedia Computing and Networking , January 1996.[11] D. J. Wetherall, J. V. Guttag, D. L. Tennenhouse, “ANTS: A toolkit forBuilding and Dynamically Deploying Network Protocols”, Open Architectures and Network Programming, 1998 IEEE , 1998 , Page(s): 117 –129.[12] B. Braden, A. Cerpa, T. Faber, B. Lindell, G. Phillips, and J. Kann.“Introduction to the ASP Execution Environment”: /active-signal/ARP/index.html .[13] “The java language: A white paper,” Tech. Rep., Sun Microsystems,1998.。

本科生毕业设计 (论文)
外文翻译
原文标题
Worlds Collide:
Exploring the Use of Social Media Technologies for
Online Learning
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世界的碰撞：
探索社交媒体技术在在线学习的应用
作者所在系别计算机科学与工程系作者所在专业计算机科学与技术作者所在班级
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完成时间2013年2月
北华航天工业学院教务处制
注：1. 指导教师对译文进行评阅时应注意以下几个方面：①翻译的外文文献与毕业设计（论文）的主题是否高度相关，并作为外文参考文献列入毕业设计（论文）的参考文献；②翻译的外文文献字数是否达到规定数量（3 000字以上）；③译文语言是否准确、通顺、具有参考价值。

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毕业设计(论文）外文文献翻译院系：财务与会计学院年级专业：201＊级财务管理姓名:学号：132148*＊*附件: 财务风险管理【Abstract】Although financial risk has increased significantly in recent years risk and risk management are not contemporary issues。

The result of increasingly global markets is that risk may originate with events thousands of miles away that have nothing to do with the domestic market。

Information is available instantaneously which means that change and subsequent market reactions occur very quickly。

The economic climate and markets can be affected very quickly by changes in exchange rates interest rates and commodity prices。

Counterparties can rapidly become problematic。

As a result it is important to ensure financial risks are identified and managed appropriately. Preparation is a key component of risk management。

【Key Words】Financial risk，Risk management，YieldsI. Financial risks arising1.1What Is Risk1.1.1The concept of riskRisk provides the basis for opportunity. The terms risk and exposure have subtle differences in their meaning. Risk refers to the probability of loss while exposure is the possibility of loss although they are often used interchangeably。

毕设外文文献+翻译1外文翻译外文原文CHANGING ROLES OF THE CLIENTS、ARCHITECTSAND CONTRACTORS THROUGH BIMAbstract:Purpose –This paper aims to present a general review of the practical implications of building information modelling (BIM) based on literature and case studies. It seeks to address the necessity for applying BIM and re-organising the processes and roles in hospital building projects. This type of project is complex due to complicated functional and technical requirements, decision making involving a large number of stakeholders, and long-term development processes.Design/methodology/approach–Through desk research and referring to the ongoing European research project InPro, the framework for integrated collaboration and the use of BIM are analysed.Findings –One of the main findings is the identification of the main factors for a successful collaboration using BIM, which can be recognised as “POWER”: product information sharing (P),organisational roles synergy (O), work processes coordination (W), environment for teamwork (E), and reference data consolidation (R).Originality/value –This paper contributes to the actual discussion in science and practice on the changing roles and processes that are required to develop and operate sustainable buildings with the support of integrated ICT frameworks and tools. It presents the state-of-the-art of European research projects and some of the first real cases of BIM application inhospital building projects.Keywords:Europe, Hospitals, The Netherlands, Construction works, Response flexibility, Project planningPaper type :General review1. IntroductionHospital building projects, are of key importance, and involve significant investment, and usually take a long-term development period. Hospital building projects are also very complex due to the complicated requirements regarding hygiene, safety, special equipments, and handling of a large amount of data. The building process is very dynamic and comprises iterative phases and intermediate changes. Many actors with shifting agendas, roles and responsibilities are actively involved, such as: the healthcare institutions, national and local governments, project developers, financial institutions, architects, contractors, advisors, facility managers, and equipment manufacturers and suppliers. Such building projects are very much influenced, by the healthcare policy, which changes rapidly in response to the medical, societal and technological developments, and varies greatly between countries (World Health Organization, 2000). In The Netherlands, for example, the way a building project in the healthcare sector is organised is undergoing a major reform due to a fundamental change in the Dutch health policy that was introduced in 2008.The rapidly changing context posts a need for a building with flexibility over its lifecycle. In order to incorporate life-cycle considerations in the building design, construction technique, and facility management strategy, a multidisciplinary collaboration is required. Despite the attempt for establishing integrated collaboration, healthcare building projects still facesserious problems in practice, such as: budget overrun, delay, and sub-optimal quality in terms of flexibility, end-user?s dissatisfaction, and energy inefficiency. It is evident that the lack of communication and coordination between the actors involved in the different phases of a building project is among the most important reasons behind these problems. The communication between different stakeholders becomes critical, as each stakeholder possesses different setof skills. As a result, the processes for extraction, interpretation, and communication of complex design information from drawings and documents are often time-consuming and difficult. Advanced visualisation technologies, like 4D planning have tremendous potential to increase the communication efficiency and interpretation ability of the project team members. However, their use as an effective communication tool is still limited and not fully explored. There are also other barriers in the information transfer and integration, for instance: many existing ICT systems do not support the openness of the data and structure that is prerequisite for an effective collaboration between different building actors or disciplines.Building information modelling (BIM) offers an integrated solution to the previously mentioned problems. Therefore, BIM is increasingly used as an ICT support in complex building projects. An effective multidisciplinary collaboration supported by an optimal use of BIM require changing roles of the clients, architects, and contractors; new contractual relationships; and re-organised collaborative processes. Unfortunately, there are still gaps in the practical knowledge on how to manage the building actors to collaborate effectively in their changing roles, and todevelop and utilise BIM as an optimal ICT support of the collaboration.This paper presents a general review of the practical implications of building information modelling (BIM) based on literature review and case studies. In the next sections, based on literature and recent findings from European research project InPro, the framework for integrated collaboration and the use of BIM are analysed. Subsequently, through the observation of two ongoing pilot projects in The Netherlands, the changing roles of clients, architects, and contractors through BIM application are investigated. In conclusion, the critical success factors as well as the main barriers of a successful integrated collaboration using BIM are identified.2. Changing roles through integrated collaboration and life-cycle design approachesA hospital building project involves various actors, roles, and knowledge domains. In The Netherlands, the changing roles of clients, architects, and contractors in hospital building projects are inevitable due the new healthcare policy. Previously under the Healthcare Institutions Act (WTZi), healthcare institutions were required to obtain both a license and a building permit for new construction projects and major renovations. The permit was issued by the Dutch Ministry of Health. The healthcare institutions were then eligible to receive financial support from the government. Since 2008, new legislation on the management of hospital building projects and real estate has come into force. In this new legislation, a permit for hospital building project under the WTZi is no longer obligatory, nor obtainable (Dutch Ministry of Health, Welfare and Sport, 2008). This change allows more freedom from the state-directed policy, and respectively,allocates more responsibilities to the healthcare organisations to deal with the financing and management of their real estate. The new policy implies that the healthcare institutions are fully responsible to man age and finance their building projects and real estate. The government?s support for the costs of healthcare facilities will no longer be given separately, but will be included in the fee for healthcare services. This means that healthcare institutions must earn back their investment on real estate through their services. This new policy intends to stimulate sustainable innovations in the design, procurement and management of healthcare buildings, which will contribute to effective and efficient primary healthcare services.The new strategy for building projects and real estate management endorses an integrated collaboration approach. In order to assure the sustainability during construction, use, and maintenance, the end-users, facility managers, contractors and specialist contractors need to be involved in the planning and design processes. The implications of the new strategy are reflected in the changing roles of the building actors and in the new procurement method.In the traditional procurement method, the design, and its details, are developed by the architect, and design engineers. Then, the client (the healthcare institution) sends an application to the Ministry of Healthto obtain an approval on the building permit and the financial support from the government. Following this, a contractor is selected through a tender process that emphasises the search for the lowest-price bidder. During the construction period, changes often take place due to constructability problems of the design and new requirements from the client.Because of the high level of technical complexity, and moreover, decision-making complexities, the whole process from initiation until delivery of a hospital building project can take up to ten years time. After the delivery, the healthcare institution is fully in charge of the operation of the facilities. Redesigns and changes also take place in the use phase to cope with new functions and developments in the medical world.The integrated procurement pictures a new contractual relationship between the parties involved in a building project. Instead of a relationship between the client and architect for design, and the client and contractor for construction, in an integrated procurement the client only holds a contractual relationship with the main party that is responsible for both design and construction. The traditional borders between tasks and occupational groups become blurred since architects, consulting firms, contractors, subcontractors, and suppliers all stand on the supply side in the building process while the client on the demand side. Such configuration puts the architect, engineer and contractor in a very different position that influences not only their roles, but also their responsibilities, tasks and communication with the client, the users, the team and other stakeholders.The transition from traditional to integrated procurement method requires a shift of mindset of the parties on both the demand and supply sides. It is essential for the client and contractor to have a fair and open collaboration in which both can optimally use their competencies. The effectiveness of integrated collaboration is also determined by the client?s capacity and strategy to organize innovative tendering procedures.A new challenge emerges in case of positioning an architect in a partnership with the contractor instead of with the client. In case of the architect enters a partnership with the contractor, an important issues is how to ensure the realisation of the architectural values as well as innovative engineering through an efficient construction process. In another case, the architect can stand at the client?s side in a strategic advisory role instead of being the designer. In this case, the architect?s responsibility is translating client?s requirements and wishes into the architectural values to be included in the design specification, and evaluating the contractor?s proposal against this. In any of this new role, the architect holds the responsibilities as stakeholder interest facilitator, custodian of customer value and custodian of design models.The transition from traditional to integrated procurement method also brings consequences in the payment schemes. In the traditional building process, the honorarium for the architect is usually based on a percentage of the project costs; this may simply mean that the more expensive the building is, the higher the honorarium will be. The engineer receives the honorarium based on the complexity of the design and the intensity of the assignment. A highly complex building, which takes a number of redesigns, is usually favourable for the engineers in terms of honorarium. A traditional contractor usually receives the commission based on the tender to construct the building at the lowest price by meeting the minimum specifications given by the client. Extra work due to modifications is charged separately to the client. After the delivery, the contractor is no longer responsible for the long-term use of the building. In the traditional procurement method, all risks are placed with theclient.In integrated procurement method, the payment is based on the achieved building performance; thus, the payment is non-adversarial. Since the architect, engineer and contractor have a wider responsibility on the quality of the design and the building, the payment is linked to a measurement system of the functional and technical performance of the building over a certain period of time. The honorarium becomes an incentive to achieve the optimal quality. If the building actors succeed to deliver a higher added-value thatexceed the minimum client?s requirements, they will receive a bonus in accordance to the client?s extra gain. The level of transparency is also improved. Open book accounting is an excellent instrument provided that the stakeholders agree on the information to be shared and to its level of detail (InPro, 2009).Next to the adoption of integrated procurement method, the new real estate strategy for hospital building projects addresses an innovative product development and life-cycle design approaches. A sustainable business case for the investment and exploitation of hospital buildings relies on dynamic life-cycle management that includes considerations and analysis of the market development over time next to the building life-cycle costs (investment/initial cost, operational cost, and logistic cost). Compared to the conventional life-cycle costing method, the dynamic life-cycle management encompasses a shift from focusing only on minimizing the costs to focusing on maximizing the total benefit that can be gained. One of the determining factors for a successful implementation of dynamic life-cycle management is the sustainable design of the building and building components, which means that the design carriessufficient flexibility to accommodate possible changes in the long term (Prins, 1992).Designing based on the principles of life-cycle management affects the role of the architect, as he needs to be well informed about the usage scenarios and related financial arrangements, the changing social and physical environments, and new technologies. Design needs to integrate people activities and business strategies over time. In this context, the architect is required to align the design strategies with the organisational, local and global policies on finance, business operations, health and safety, environment, etc.The combination of process and product innovation, and the changing roles of the building actors can be accommodated by integrated project delivery or IPD (AIA California Council, 2007). IPD is an approach that integrates people, systems, business structures and practices into a process that collaboratively harnesses the talents and insights of all participants to reduce waste and optimize efficiency through all phases of design, fabrication and construction. IPD principles can be applied to a variety of contractual arrangements. IPD teams will usually include members well beyond the basic triad of client, architect, and contractor. At a minimum, though, an Integrated Project should include a tight collaboration between the client, the architect, and the main contractor ultimately responsible for construction of the project, from the early design until the project handover. The key to a successful IPD is assembling a team that is committed to collaborative processes and is capable of working together effectively. IPD is built on collaboration. As a result, it can only be successful if the participants share and apply common values and goals.3. Changing roles through BIM applicationBuilding information model (BIM) comprises ICT frameworks and tools that can support the integrated collaboration based on life-cycle design approach. BIM is a digital representation of physical and functional characteristics of a facility. As such it serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its lifecycle from inception onward (National Institute of Building Sciences NIBS, 2007). BIM facilitates time and place independent collaborative working. A basic premise of BIM is collaboration by different stakeholders at different phases of the life cycle of a facility to insert, extract, update or modify information in the BIM to support and reflect the roles of that stakeholder. BIM in its ultimate form, as a shared digital representation founded on open standards for interoperability, can become a virtual information model to be handed from the design team to the contractor and subcontractors and then to the client.BIM is not the same as the earlier known computer aided design (CAD). BIM goes further than an application to generate digital (2D or 3D) drawings. BIM is an integrated model in which all process and product information is combined, stored, elaborated, and interactively distributed to all relevant building actors. As a central model for all involved actors throughout the project lifecycle, BIM develops andevolves as the project progresses. Using BIM, the proposed design and engineering solutions can be measured against the client?s requirements and expected building performance. The functionalities of BIM to support the design process extend to multidimensional (nD), including: three-dimensional visualisation and detailing, clash detection, material schedule, planning, costestimate, production and logistic information, and as-built documents. During the construction process, BIM can support the communication between the building site, the factory and the design office– which is crucial for an effective and efficient prefabrication and assembly processes as well as to prevent or solve problems related to unforeseen errors or modifications. When the building is in use, BIM can be used in combination with the intelligent building systems to provide and maintain up-to-date information of the building performance, including the life-cycle cost.To unleash the full potential of more efficient information exchange in the AEC/FM industry in collaborative working using BIM, both high quality open international standards and high quality implementations of these standards must be in place. The IFC open standard is generally agreed to be of high quality and is widely implemented in software. Unfortunately, the certification process allows poor quality implementations to be certified and essentially renders the certified software useless for any practical usage with IFC. IFC compliant BIM is actually used less than manual drafting for architects and contractors, and show about the same usage for engineers. A recent survey shows that CAD (as a closed-system) is still the major form of technique used in design work (over 60 per cent) while BIM is used in around 20 percent of projects for architects and in around 10 per cent of projects for engineers and contractors.The application of BIM to support an optimal cross-disciplinary and cross-phase collaboration opens a new dimension in the roles and relationships between the building actors. Several most relevant issues are: the new role of a model manager; the agreement on the access right and IntellectualProperty Right (IPR); the liability and payment arrangement according to the type of contract and in relation to the integrated procurement; and the use of open international standards.Collaborative working using BIM demands a new expert role of a model manager who possesses ICT as well as construction process know-how (InPro, 2009). The model manager deals with the system as well as with the actors. He provides and maintains technological solutions required for BIM functionalities, manages the information flow, and improves the ICT skills of the stakeholders. The model manager does not take decisions on design and engineering solutions, nor the organisational processes, but his roles in the chain of decision making are focused on:the development of BIM, the definition of the structure and detail level of the model, and the deployment of relevant BIM tools, such as for models checking, merging, and clash detections;the contribution to collaboration methods, especially decision making and communication protocols, task planning, and risk management;and the management of information, in terms of data flow and storage, identification of communication errors, and decision or process (re-)tracking.Regarding the legal and organisational issues, one of the actual questions is: “In what way does the intellectual property right (IPR) in collaborative working using BIM differ from the IPR in a traditional teamwork?”. In terms of combine d work, the IPR of each element is at tached to its creator. Although it seems to be a fully integrated design, BIM actually resulted from a combination of works/elements; for instance: the outline of the building design, is created by the architect, the design for theelectrical system, is created by the electrical contractor, etc. Thus, in case of BIM as a combined work, the IPR is similar to traditional teamwork. Working with BIM with authorship registration functionalities may actually make it easier to keep track of the IPR.How does collaborative working, using BIM, effect the contractual relationship? On the one hand,collaborative working using BIM does not necessarily change the liability position in the contract nor does it obligate an alliance contract. The General Principles of BIM A ddendum confirms: …This does not effectuate or require a restructuring of contractual relationships or shifting of risks between or among the Project Participants other than as specifically required per the Protocol Addendum and its Attachments? (ConsensusDOCS, 2008). On the other hand, changes in terms of payment schemes can be anticipated. Collaborative processes using BIM will lead to the shifting of activities from to the early design phase. Much, if not all, activities in the detailed engineering and specification phase will be done in the earlier phases. It means that significant payment for the engineering phase, which may count up to 40 per cent of the design cost, can no longer be expected. As engineering work is done concurrently with the design, a new proportion of the payment in the early design phase is necessary.4. Review of ongoing hospital building projects using BIMIn The Netherlands, the changing roles in hospital building projects are part of the strategy, which aims at achieving a sustainable real estate in response to the changing healthcare policy. Referring to literature and previous research, the main factors that influence the success of the changing roles can be concluded as: the implementation of an integrated procurementmethod and a life-cycle design approach for a sustainable collaborative process; the agreement on the BIM structure and the intellectual rights; and the integration of the role of a model manager. The preceding sections have discussed the conceptual thinking on how to deal with these factors effectively. This current section observes two actual projects and compares the actual practice with the conceptual view respectively.The main issues, which are observed in the case studies, are: the selected procurement method and the roles of the involved parties within this method;the implementation of the life-cycle design approach;the type, structure, and functionalities of BIM used in the project;the openness in data sharing and transfer of the model, and the intended use of BIM in the future; and the roles and tasks of the model manager.The pilot experience of hospital building projects using BIM in the Netherlands can be observed at University Medical Centre St Radboud (further referred as UMC) and Maxima Medical Centre (further referred as MMC). At UMC, the new building project for the Faculty of Dentistry in the city of Nijmegen has been dedicated as a BIM pilot project. At MMC, BIM is used in designing new buildings for Medical Simulation and Mother-and-Child Centre in the city of Veldhoven.The first case is a project at the University Medical Centre (UMC) St Radboud. UMC is more than just a hospital. UMC combines medical services, education and research. More than 8500 staff and 3000 students work at UMC. As a part of the innovative real estate strategy, UMC has considered to use BIM for its building projects. The new development of the Faculty ofDentistry and the surrounding buildings on the Kapittelweg in Nijmegen has been chosen as a pilot project to gather practical knowledge and experience on collaborative processes with BIM support.The main ambition to be achieved through the use of BIM in the building projects at UMC can be summarised as follows: using 3D visualisation to enhance the coordination and communication among the building actors, and the user participation in design;integrating the architectural design with structural analysis, energy analysis, cost estimation, and planning;interactively evaluating the design solutions against the programme of requirements and specifications;reducing redesign/remake costs through clash detection during the design process; andoptimising the management of the facility through the registration of medical installations andequipments, fixed and flexible furniture, product and output specifications, and operational data.The second case is a project at the Maxima Medical Centre (MMC). MMC is a large hospital resulted from a merger between the Diaconessenhuis in Eindhoven and St Joseph Hospital in Veldhoven. Annually the 3,400 staff of MMC provides medical services to more than 450,000 visitors and patients. A large-scaled extension project of the hospital in Veldhoven is a part of its real estate strategy. A medical simulation centre and a women-and-children medical centre are among the most important new facilities within this extension project. The design has been developed using 3D modelling with several functionalities of BIM.The findings from both cases and the analysis are as follows.Both UMC and MMC opted for a traditional procurement method in which the client directly contracted an architect, a structural engineer, and a mechanical, electrical and plumbing (MEP) consultant in the design team. Once the design and detailed specifications are finished, a tender procedure will follow to select a contractor. Despite the choice for this traditional method, many attempts have been made for a closer and more effective multidisciplinary collaboration. UMC dedicated a relatively long preparation phase with the architect, structural engineer and MEP consultant before the design commenced. This preparation phase was aimed at creating a common vision on the optimal way for collaboration using BIM as an ICT support. Some results of this preparation phase are: a document that defines the common ambition for the project and the collaborative working process and a semi-formal agreement that states the commitment of the building actors for collaboration. Other than UMC, MMC selected an architecture firm with an in-house engineering department. Thus, the collaboration between the architect and structural engineer can take place within the same firm using the same software application.Regarding the life-cycle design approach, the main attention is given on life-cycle costs, maintenance needs, and facility management. Using BIM, both hospitals intend to get a much better insight in these aspects over the life-cycle period. The life-cycle sustainability criteria are included in the assignments for the design teams. Multidisciplinary designers and engineers are asked to collaborate more closely and to interact with the end-users to address life-cycle requirements. However, ensuring the building actors to engage in an integrated collaboration to generate sustainable design solutions that meet the life-cycle。

Environmental problems caused by Istanbul subway excavation and suggestionsfor remediation伊斯坦布尔地铁开挖引起的环境问题及补救建议Ibrahim Ocak Abstract：Many environmental problems caused by subway excavations have inevitably become an important point in city life. These problems can be categorized as transporting and stocking of excavated material, traffic jams, noise, vibrations, piles of dust mud and lack of supplies. Although these problems cause many difficulties,the most pressing for a big city like Istanbul is excava tion,since other listed difficulties result from it. Moreover, these problems are environmentally and regionally restricted to the period over which construction projects are underway and disappear when construction is finished. Currently, in Istanbul, there are nine subway construction projects in operation, covering approximately 73 km in length; over 200 km to be constructed in the near future. The amount of material excavated from ongoing construction projects covers approximately 12 million m3. In this study, problems—primarily, the problem with excavation waste(EW)—caused by subway excavation are analyzed and suggestions for remediation are offered.摘要：许多地铁开挖引起的环境问题不可避免地成为城市生活的重要部分。

英文原文：Java is a simple, object-oriented, distributed, interpreted, robust security, structure-neutral, portable, high performance, multithreaded dynamic language. The main advantage of Java language, Java applications across hardware platforms and operating systems for transplant - this is because the JVM is installed on each platform can understand the same byte code. Java language and platform scalability is very strong. At the low end, Java language is the first open standards technology support enterprise one, support the use of XML and Web service can not stride business lines to share information and applications Cheng Xu.There are three versions of Java platform, which makes software developers, service providers and equipment manufacturers can target specific market development:1. Java SE form applications. Java SE includes support for Java Web services development classes, and for the Java Platform, Enterprise Edition (Java EE) to provide a basis. Most Java developers use Java SE 5, also known as Java 5.0 or "Tiger".2. Java EE formerly known as J2EE. Enterprise Edition to help develop and deploy portable, robust, scalable and secure server-side Java applications. Java SE Java EE is built on the foundation, which provides Web services, component model, management and communication API, can be used to achieve enterprise-class service-oriented architecture and Web 2.0 applications.3. Java ME formerly known as J2ME. Java ME devices in mobile and embedded applications running on a robust and flexible environment. Java ME includes flexible user interfaces, robust security model, and many built-in network protocols and networking that can be dynamically downloaded and extensive support for offline applications. Java ME-based application specification only write once and can be used in many devices and can use the native features of each device.Java language is simple. Java language syntax and the C language and C ++ language is very close, Java discarded the C++, rarely used, hard to understand the characteristics, such as operator overloading, multiple inheritance, the mandatory automatic type conversion. Java language does not use pointers, and provides automated waste collection. Java is an object-oriented language. Java language provides classes, interfaces and inheritance of the original language, for simplicity, only supports single inheritance between classes, but support multiple inheritance between interfaces and support classes and interfaces to achieve between the mechanism (keyword implements) . Java language fully supports dynamic binding, and C ++ language used only for dynamic binding of virtual functions. In short, Java language is a pure object-oriented programming language. Java language is distributed. Java language support for Internet application development, Java's RMI (remote method activation) mechanism is also an important means of developing distributed applications. Java language is robust. Java's strong type system, exception handling, automated waste collection is an important guarantee robust Java programs. Java language is safe. Java is often used in network environment, this, Java provides a security mechanism to prevent malicious code attacks.Java language is portable. This portability comes from the architecture neutrality. Java system itself is highly portable. Java language is multi-threaded. In the Java language, the thread is a special object, it must Thread class or the son (Sun) class to create. Java language support simultaneous execution of multiple threads, and provide synchronization mechanisms between threads (keyword synchronized).Java language features make Java an excellent application of unparalleled robustness and reliability, which also reduced application maintenance costs. Java on the full support of object technology and Java Platform API embedded applications to reduce development time and reduce costs. Java's compile once, run everywhere feature can make it anywhere available to provide an open architecture and multi-platform, low-cost way of transmitting information between. Hibernate Hibernate is a lightweight JDBC object package. It is an independent object persistence framework, and the App Server, and EJB is no necessary link. Hibernate can use JDBC can be used in any occasion, such as Java application, database access code, DAO interface implementation class, or even access the database inside a BMP code. In this sense, Hibernate, and EB is not a category of things that did not exist either-or relationship.Hibernate and JDBC is a closely related framework, the Hibernate and JDBC driver compatibility, and databases have some relationship, but the Java program and use it, and the App Server does not have any relationship, there was no compatibility issues. 1614Hibernate provides two Cache, first-level cache is a Session-level cache, which cache belongs to the scope of services. This level of cache by the hibernate managed without the need for intervention under normal circumstances; second-level cache is SessionFactory-level cache, it belongs to the process of range or scope of the cache cluster. This level of cache can be configured and changed, and can be dynamically loaded and unloaded. Hibernate query results also provide a query cache, it depends on the second level cache.When an application called Session's save (), update (), saveOrUpdate (), get () or load (), and the query interface call list (), iterate () or filter () method, if the Session cache does not exist a corresponding object, Hibernate will put the object to the first level cache. When cleaning the cache, Hibernate objects according to the state of the cache changes to synchronize update the database. Session for the application provides two methods of managing the cache: evict (Object obj): removed from the cache parameters of the specified persistent object. clear (): Empty the cache of all persistent objects.Hibernate second-level cache strategy general process is as follows:1) The condition when a query is always issued a select * from table_name where .... (Select all fields) such as SQL statement to query the database, an access to all of the data object.2) all the data objects to be placed under the ID to the second level cache.3) When the Hibernate object-based ID to access the data, the first check from the Session a cache; finding out, if the configuration of the secondary cache, then the secondary cache from the investigation; finding out, and then query the database, the results in accordance with the ID into the cache.4) remove, update and increase the time data, while updating the cache. Hibernate second against the conditions of the Query Cache.Hibernate object-relational mapping for the delay and non-delay object initialization. Non-lazy when reading an object and the object will be all read out together with other objects. This sometimes results in hundreds (if not thousands of words) select statement when reading the object implementation. This problem sometimes occurs when using the two-way relationship, often leading to the databases to be read during the initialization phase out. Of course, you can take the trouble to examine each object and other objects of Guanxi, and to the most expensive of the Shan Chu, but in the last, we may therefore lose Le ORM tool this Xiangzai obtained Bian Li.A cache and secondary cache of comparison: the first level cache second level cache data stored in the form of interrelated persistent objects the object of bulk data cache range of the scope of services, each transaction has a separate first-level cache process range or scope of the cluster, the cache is the same process or cluster to share on all matters within the concurrent access policies because each transaction has a separate first-level cache, concurrency problem does not occur without the need to provide concurrent access policy will be a number of matters simultaneous access to the same second-level cache data, it is necessary to provide appropriate concurrent access policies, to ensure that a particular transaction isolation level data expiration policies did not provide data expiration policies. Object in a cache will never expire, unless the application explicitly clear the cache or clear a specific object must provide data expiration policies, such as memory cache based on the maximum number of objects, allowing objects in the cache of the most a long time, and allowing the object in the cache the longest idle time of physical memory and hard disk memory storage medium. First of all bulk data objects stored in the memory-based cache, when the number of objects in memory to data expiration policy specified limit, the remaining objects will be written on the hard disk cache. Caching software implementation of the Hibernate Session is included in the realization of the cache provided by third parties, Hibernate provides only a cache adapter (CacheProvider). Used to plug into a particular cache in Hibernate. Way cache enabled applications by as long as the Session interface implementation save, update, delete, data loading and query the database operations, Hibernate will enable first-level cache, the data in the database in the form of an object copied to the cache For batch updates and bulk delete operations, if you do not want to enable first-level cache, you can bypass the Hibernate API, JDBC API directly to perform that operation. Users can type in a single class or a single set of second-level cache size on the configuration. If the instance of the class are frequently read but rarely modified, you can consider using a second-level cache. Only for a class or set of second-level cache is configured, Hibernate will run when an instance of it to the second-level cache. User management means the first level cache of physical media for the memory cache, because the memory capacity is limited, must pass the appropriate search strategies and retrieval methods to limit the number of objects loaded. Session of the evit () method can explicitly clear the cache a specific object, but this method is not recommended. Second-level cache memory andthe physical media can be a hard disk, so the second-level cache can store large amounts of data, data expiration policy maxElementsInMemory property values can control the number of objects in memory. Second-level cache management mainly includes two aspects: Select to use the second-level cache of persistent classes, set the appropriate concurrency strategy: Select the cache adapter, set the appropriate data expiration policies.One obvious solution is to use Hibernate's lazy loading mechanism provided. This initialization strategy is only invoked in an object-to-many or many to many relationship between its relationship only when read out of the object. This process is transparent to the developer, and only had a few requests for database operations, it will be more obvious performance have open. This will be by using the DAO pattern abstracts the persistence time of a major problem. Persistence mechanisms in order to completely abstract out all of the database logic, including open or closed session, can not appear in the application layer. The most common is the realization of the simple interface of some DAO implementation class to encapsulate the database logic completely. A fast but clumsy solution is to give up DAO mode, the database connection logic to add the application layer. This may be an effective small applications, but in large systems, this is a serious design flaw, preventing the system scalability.Struts2Struts2 is actually not a stranger to the Web frameworks, Struts2 is Webwork design ideas as the core, absorb Struts1 advantages, so that the Struts2 is the product of the integration Struts1 and Webwork.MVC Description: Struts2 WebWork is compatible with the MVC framework Struts1 and since, that the MVC framework on the MVC framework will have to make a brief, limited to a brief, if want to learn more about MVC can view the related knowledge document, or to find a Struts1 books, I believe the above is not rare on the length of MVC. Closer to home, in fact, Java the present situation of these frameworks, its ultimate goal is to contact coupling, whether Spring, Hibernate or the MVC framework, are designed to increase contact with coupling reuse. MVC contact with the coupling between View and Model. MVC consists of three basic parts: Model, View and Controller, these three parts work together to minimize the coupling to increase the scalability of the program and maintainability. Various parts of the implementation technology can be summarized as follows:1) Model: JavaBean, EJB's EntityBean2) View: JSP, Struts in TagLib3) Controller: Struts the ActionServlet, ActionTo sum up the advantages of MVC mainly about aspects:1) corresponds to multiple views can be a model. By MVC design pattern, a model that corresponds to multiple views, you can copy the code and the code to reduce the maintenance amount, if model changes, but also easy to maintain2) model the data returned and display logic separate. Model data can be applied to any display technology, for example, use the JSP page, Velocity templates, or directly from Excel documents, etc.3) The application is separated into three layers, reducing the coupling between the layers, providing application scalability4) The concept of layers is also very effective, because it put the different models and different views together, to complete a different request. Therefore, the control layer can be said to include the concept of user requests permission5) MVC more software engineering management. Perform their duties in different layers, each layer has the same characteristics of the components is beneficial tool by engineering and production management of program codeStruts2 Introduction: Struts2 Struts1 development appears to come from, but in fact Struts1 Struts2 and design ideas in the framework of the above is very different, Struts2 WebWork's design is based on the core, why not follow the Struts1 Struts2 design ideas After all, Struts1 in the current enterprise applications market is still very big in the, Struts1 some shortcomings:1) support the performance of a single layer2) coupled with the Servlet API serious, this could be the Execute method from the Action Statement which you can see them3) The code depends Struts1 API, there are invasive, this can be written when the Action class and look out FormBean, Action Struts in Action class must implement The reason for Struts2 WebWork's design for the core point is the recent upward trend of WebWork and play WebWork not Struts1 above those shortcomings, more MVC design ideas, and more conducive to reuse the code. Based on the above description can be read out, Struts2 architecture and architecture Struts1 very different, Struts1 is to use the ActionServlet as its central processor, Struts2 is using an interceptor (FilterDispatcher) as its central processor, so One benefit is to make Action class and Servlet API was isolated.Struts2 simple process flow is as follows:1) browser sends a request2) the processor to find the corresponding file under struts.xml the Action class to process the request3) WebWork interceptor chain applications automatically request common functions, such as: WorkFlow, Validation functions4) If Struts.xml Method configuration file parameters, then call the corresponding Action Method parameters in the Method class method, or call the Execute method to deal with common user request5) Action class method returns the results of the corresponding response to the browserStruts2 and Struts1 contrast:1) Action class impleme achieve the time to achieve any classes and interfaces, while providing a ActionSupport class Struts2, however, not required.2) Struts1 the Action class is the singleton pattern, must be designed into the thread-safe, Struts2 was generated for each request for an instance3) Struts1 the Action class dependence and the Servlet API, execute the method from its signature can be seen, execute method has two parameters Servlet HttpServletRequest and HttpServletResponse, Struts2 is not dependent on the ServletAPI4) Struts1 depends on the Servlet API the Web elements, therefore, of Action Struts1 when testing is difficult, it needs with other testing tools, Struts2 in Action can be as testing a number of other classes as Service Model layer test5) Struts1 of Action and the View through the ActionForm or its sub-class of data transmission, although there LazyValidationForm this ActionForm appearance, but still can not like the other levels as a simple POJO data transfer, and Struts2 would like expect change becomes a reality6) Struts1 binding of the JSTL, the preparation of convenience for the page, Struts2 integrates ONGL, you can use JSTL, Therefore, Struts2 is more powerful expression language underCompared with Struts2 WebWork: Struts2 actually WebWork2.3, however, Struts2 WebWork, or with a little difference:1) Struts2 IOC no longer support the built-in containers, use Spring's IOC container2) Struts2 Ajax for Webwork features some of the label to use Dojo to be replacedServletServlet is a server-side Java application, platform and protocol independent features that can generate dynamic Web pages. Customer requests to play it (Web browser or other HTTP client) and server response (HTTP server, database or application) of the middle layer. Servlet Web server is located inside the server-side Java applications started from the command line with the traditional application of different Java, Servlet loaded by the Web server, the Web server must include the Java Virtual Machine to support Servlet.HTTP Servlet using a HTML form to send and receive data. To create an HTTP Servlet, need to extend the HttpServlet class, the class is a special way to handle HTML forms GenericServlet a subclass. HTML form is <FORM> and </ FORM> tag definition. Form typically includes input fields (such as text input fields, check boxes, radio buttons and selection lists) and a button for submitting data. When submitting information, they also specify which server should implement the Servlet (or other program). HttpServlet class contains the init (), destroy (), service () and other methods. Where init () and destroy () method is inherited.init () method: In the Servlet life period, only run once init () method. It is executed when the server load Servlet. You can configure the server to start the server or the client's first visit to Servlet fashion into the Servlet. No matter how many clients to access Servlet, will not repeat the init (). The default init () method is usually to meet the requirements, but can also use custom init () method to overwrite it, typically the management server-side resources. For example, you may write a custom init () to be used only once a load GIF images, GIF images and improve the Servlet returns with the performance of multiple clients request. Another example is to initialize the database connection. The default init () method sets the Servlet initialization parameters, and use it's ServletConfig object parameter to start the configuration, all covered by init () method of the Servlet should call super.init () to ensure that stillperform these tasks. In the call to service () method before, make sure you have completed the init () method.service () method: service () method is the core of Servlet. Whenever a client requests a HttpServlet object, the object of the service () method must be called, and passed to this method a "request" (ServletRequest) objects and a "response" (ServletResponse) object as a parameter. Already exists in the HttpServlet service () method. The default service function is invoked with the HTTP request method to do the corresponding functions. For example, if the HTTP request method is GET, the default on the call to doGet (). Servlet Servlet support should do HTTP method override function. Because HttpServlet.service () method checks whether the request method calls the appropriate treatment, unnecessary coverage service () method. Just do cover the corresponding method on it.Servlet response to the following types: an output stream, the browser based on its content type (such as text / HTML) to explain; an HTTP error response, redirect to another URL, servlet, JSP.doGet () method: When a client through the HTML form to send a HTTP GET request or when a direct request for a URL, doGet () method is called. Parameters associated with the GET request to the URL of the back, and send together with this request. When the server does not modify the data, you should use doGet () method. doPost () method: When a client through the HTML form to send a HTTP POST request, doPost () method is called. Parameters associated with the POST request as a separate HTTP request from the browser to the server. When the need to modify the server-side data, you should use the doPost () method.destroy () method: destroy () method is only executed once, that is, stop and uninstall the server to execute the method of Servlet. Typically, the Servlet as part of the process server to shut down. The default destroy () method is usually to meet the requirements, but can also cover it, and typically manage server-side resources. For example, if the Servlet will be accumulated in the run-time statistics, you can write a destroy () method is used in Servlet will not load the statistics saved in the file. Another example is to close the database connection.When the server uninstall Servlet, it will in all service () method call is completed, or at a specified time interval after the call to destroy () method. Running a Servlet service () method may have other threads, so make sure the call destroy () method, the thread has terminated or completed.GetServletConfig () method: GetServletConfig () method returns a ServletConfig object, which used to return the initialization parameters and ServletContext. ServletContext interface provides information about servlet environment. GetServletInfo () method: GetServletInfo () method is an alternative method, which provides information on the servlet, such as author, version, copyright.When the server calls sevlet of Service (), doGet () and doPost () of these three methods are needed "request" and "response" object as a parameter. "Request" object to provide the requested information, and the "response" object to provide a response message will be returned to the browser as a communications channel.javax.servlet packages in the relevant classes for the ServletResponse andServletRequest, while the javax.servlet.http package of related classes for the HttpServletRequest and HttpServletResponse. Servlet communication with the server through these objects and ultimately communicate with the client. Servlet through call "request" object approach informed the client environment, server environment, information and all information provided by the client. Servlet can call the "response" object methods to send response, the response is ready to send back to clientJSPJavaServerPages (JSP) technology provides a simple and fast way to create a display content dynamically generated Web pages. Leading from the industry, Sun has developed technology related to JSP specification that defines how the server and the interaction between the JSP page, the page also describes the format and syntax.JSP pages use XML tags and scriptlets (a way to use script code written in Java), encapsulates the logic of generating page content. It labels in various formats (HTML or XML) to respond directly passed back to the page. In this way, JSP pages to achieve a logical page design and display their separation.JSP technology is part of the Java family of technologies. JSP pages are compiled into a servlet, and may call JavaBeans components (beans) or EnterpriseJavaBeans components (enterprise beans), so that server-side processing. Therefore, JSP technology in building scalable web-based applications play an important role.JSP page is not confined to any particular platform or web server. JSP specification in the industry with a wide range of adaptability.JSP technology is the result of collaboration with industry, its design is an open, industry standards, and support the vast majority of servers, browsers and related tools. The use of reusable components and tags replaced on the page itself relies heavily on scripting languages, JSP technology has greatly accelerated the pace of development. Support the realization of all the JSP to Java programming language-based scripting language, it has inherent adaptability to support complex operations.JqueryjQuery is the second prototype followed by a good Javascrīpt framework. Its purpose is: to write less code, do more.It is lightweight js library (compressed only 21k), which is less than the other js library which, it is compatible CSS3, is also compatible with all browsers (IE 6.0 +, FF 1.5 +, Safari 2.0 +, Opera 9.0 +).jQuery is a fast, simple javaScript library, allowing users to more easily dealwith HTML documents, events, to achieve animation effects, and provide easy AJAX for interactive web site.jQuery also has a larger advantage is that it is all documented, and various applications are very detailed, as well as many mature plug-ins available.jQuery's html page to allow users to maintain separate code and html content, that is, no need to insert in the html inside a pile of js to call the command, and you can just define id.jQuery is the second prototype followed by a good Javascrīpt framework. On theprototype I use small, simple and understood. However, after using the jquery immediately attracted by her elegance. Some people use such a metaphor to compare the prototype and jquery: prototype like Java, and jquery like a ruby. In fact I prefer java (less contact with Ruby Bale), but a simple jquery does have considerable practical appeal ah! I put the project in the framework jquery as its the only class package. Use the meantime there is also a little bit of experience, in fact, these ideas, in the jquery documentation above may also be speaking, but still it down to stop notes.译文：Java是一种简单的，面向对象的，分布式的，解释型的，健壮安全的，结构中立的，可移植的，性能优异、多线程的动态语言。

天津科技大学本科生毕业设计（论文）外文资料翻译学院：材料科学与化学工程学院专业：高分子材料与工程姓名：阮孝顺学号：10032411指导教师（签名）：2014年3月15日基底机械附着防水体系ACC板适宜性的确认及其高风压下的强度Michal Bartko a, Hiroyuki Miyauchi a,*, Kyoji Tanaka ba忠南大学，305-764，大田，南韩b日本东京工业大学，226-8503，神奈川县，日本2012年9月7日收到，2013年5月9日收到修改稿，2013年5月19日接受，2013年6月19日发表【摘要】受到强风的影响，机械连接防水体系的蒸气压混凝土板（AAC）的可靠性需要验证。

通过静态和动态拉伸试验研究AAC面板紧固件的优点。

对最常用的机械和化学紧固件的优点和AAC断裂类型进行测试观察。

静态强度值介于2.0至5.0kN之间，动态强度下降范围在１.5到2.2kN之间。

而且，我们创造性的应用了弹性粘合剂来代替常用的环氧树脂从而广泛的消除了ACC断裂。

我们使用专门设计和生产的恒定负载型动态测试仪，检查完整的机械连接的防水体系的特征。

我们测试了两种聚氯乙烯（PVC）卷材的类型和两种不同的卷材和圆盘连接方法。

重复实验，直到失败的次数高达100,000次，并记录在相同强度的强风下实际屋顶发生的断裂类型。

也发现了紧固件的动态强度和完全防水体系之间的关系，证明了AAC面板有足够承载力能够作为机械连接防水体系的基底，也探究出了确定紧固件最大间距的方法。

2013年爱思唯尔公司保留所有权。

【关键词】：机械连接防水体系；AAC镶基板；阻力风；静态和动态测试；断口模式；体系设计方法2013年爱思唯尔公司保留所有权。

1.前言机械连接防水体系是一种干式防水体系，有几个优势，比如不受裂缝和联合移动的影响。

该防水体系适用于多种类型的基板，安装简单容易，可以方便的修复，在技术上和经济上可行。

因此，该体系在日本和全球的使用量正在增长。

Influence of underground water seepage flow on surrounding rockdeformation of multi-arch tunnelAbstract: Based on a typical multi-arch tunnel in a freeway, the fast Lagrangian analysis of continua in3 dimensions(FLAC ) was used to calculate the surrounding rock deformation of the tunnel under which the effect of underground water seepage flow was taken into account or not. The distribution of displacement field around the multi-arch tunnel, which is influenced by the seepage field, was gained. The result indicates that the settlement values of the vault derived from coupling analysis are bigger when considering the seepage flow effect than that not considering. Through the contrast of arch subsidence quantities calculated by two kinds of computation situations, and the comparison between the calculated and measured value of tunnel vault settlement, it is found that the calculated value(5.7−6.0 mm) derived from considering the seepage effect is more close to the measured value(5.8−6.8 mm). Therefore, it is quite necessary to consider the seepage flow effect of the underground water in aquiferous stratum for multi-arch tunnel design. key words: multi-arch tunnel; underground water seepage flow; coupling flow and stress; surrounding rock deformation; vault settlement1 IntroductionWith high speed development of our national economy, the highway is constructed on large-scale all around the country. Along the freeway from Changsha to Chongqing(one section of which is from Changde to Jishou), many tunnels have to be constructed. As these tunnels’s topography and geomorphic conditions are very complex and the rain is very rich, the invasion of underground water and surface water is a difficult problem in the tunnel construction and its future function. In the past railway and highway tunnel construction, some effective waterproof construction technologies were proposed . But the researches on the mechanism of coupling function of fluid and stress and its influence on tunnels are not enough. For example, LIU and CHENcalculated and analyzed the double-arch tunnel structure in water-eroded groove but did not consider the underground water seepage force. YANG et al studied the earthquake response of large span and double-arch shallow tunnel, combining with dynamic stress but without underground water seepage stress. In fact, tunnel excavation forms two secondary stresses fields that can change the distribution of initial rock stress field and theunderground water seepage field. And the seepage flow of underground water also has importantinfluence on the stability of tunnel.Generally speaking, when the surface water seeps in underground, it will constitute the initial seepage flow field together with the underground water. But after tunnel excavation the initial seepage flow field will be destructed. In order to achieve a newbalance, it can produce a new seepage flow field around the tunnel with the underground water flowing into the tunnel. The pore-water pressure can change the stress field of adjacent rock mass. This problem is the coupling flow and stress question on which some scholars study now . LI et al analyzed the subsea tunnel withcoupling process and LEE and NAM discussed the seepage flow force around the tunnel with coupling analysis. In order to know the effect of underground water seepage flow on the surrounding rock deformation of tunnel, a multi-arch tunnel(named Bi-Ma-Xi tunnel) engineering was analyzed with FLAC in this work.2 Engineering and geology conditions2.1 TopographyThe tunnel locates at a hill on long-term weathering and denudation action. In the tunnel area, there are some gullies that primarily s trike towards north and some strike from east to north. Tunnel axis direction and topographic contour line are intersected with orthogonal or a great angle at section K218+087−K218+380 and with a small angle or even parallel at section K218+380− K218+565. The topography is rather steep and forms a “V” type gully. The general hill strike is about 340˚, which is close from north to south. The topography slope is about 15˚−35˚. The green vegetation is mainly the small bamboo and herbaceous plants. The rock bed is visible in some places.2.2 Lithologyccording to engineering geology survey and drilling exposure data, the stratum of3D [1−3] 4][5]surveying area from young to old is as follows.The Quaternary Holocene(Qh): the soil-like loam layer, snuff color, plastic-stiffly,0−4.60 m thick. This layer is ignored in numerical model.The Upper Cretaceous (K2j): Sandstone layer, red brown or palm fibre or dust colour,fine-grained structure. The calcareous cemented rock layer is mixed with mud cemented rock layer and the former is the main part and it is thin and medium thickness structural layer. The horizontal bedding layer develops and the dip angle is small. According to weathered degree the stratum can be divided into three layers from the top down: intensely, weakly and tinily weathered layer. The sketch map of geology section is shown in Fig.1.Fig.1 Sketch of geological profile for tunnel2.3 Geology constitutionIn tunnel area there is no large fracture structure and nor any new tectogenesis. The geology constitution is a monoclinal structure. The rock dip direction of general occurrence is 95˚−115˚. The dip angle distribution ranges from 8˚ to15˚. Three sets of joint crack develop: 1) dip direction 148˚, dip angle 89˚;2) dip direction 350˚, dip angle 56˚; 3) dip direction 225˚, dip angle 77˚. The joint cracks mostly twist with pressure and crack faces are almost close. Minorities of the crack faces are patulous and the distance between two cracks often varies from 5 to 20 cm. The connectivity is fairly good.3 Construction of 3D numerical model3.1 model of numerical calculationThis tunnel is a freeway multi-arch tunnel, of which the left one and right one are general parallel. The two tunnels are about symmetrical by the middle arch wall. The average thickness of middle wall is 2.1 m. The key dimensions of tunnel section are shown in Fig.2.Fig.2 Sketch of multi-tunnel cross section (unit: cm)When modeling the tunnel, the direction along the tunnel is y-axis and in horizontal plane the perpendicularity of tunnel direction is x-axis and plumb upward is z-axis. The influence of tunnel excavation is considered. The radius of influence range is above 3 times of one tunnel span. So in width direction, 50 m extends respectively outside the left and right tunnel, plus the span itself, width direction calculation range is 125 m. Downwards from the original point is 3 times of the height of the tunnel, which equals 45 m and upward is till the earth’s surface (does not consider the clay layer, calculating depth range includes intensely, weakly, tinily weathered red sandstone from above to below respectively). The buried depth of the tunnel is about 25 m. Plus the 10 m of its height, in z-axis the depth is 80 m. Along the tunnel direction an unit length is considered because tunnel excavation can be considered asa plane-strain problem. The size of the 3D numerical model is 125 m×80 m×1 m. The 3D numerical model and its coordinate axis location are shown in Fig.3.Fig.3 3D numerical model of tunnel in FLACThe displacement boundary conditions are adopted in numerical model. Bottom border is constrained with vertical displacement and upper border is free border. Both left and right border are restrained with horizontal displacement. The same boundary conditions are applied in both the front and back borders in y-axis.3.2 Calculation parametersThe mechanics parameters in numerical analysis are provided by geotechnical engineering investigation data and combined with the national criterion need and parameters discount request in numerical simulation. The mechanics parameters of the surrounding rock and the C25 concrete middle arch wall are listed in Table 1. The surrounding rock and the concrete intensity criteria adopted is the elastic-plastic criterion of Mohr-Coulomb. Table 2 shows the surrounding rock relevant seepage flow parameters when coupling problem is considered in numerical simulation. Table 3 lists the parameters of shot concrete(primary lining) and anchor support structure of the multi-arch tunnel. In this calculation process, the parameters of Grade IV surrounding rock supporting system are adopted. And only the affection of the anchor and shotconcrete is considered. The effect of secondary lining is not considered in numerical simulation.4 Discussion on calculation results4.1 Surrounding rock deformation characteristics without underground water seepage flowBased on the established numerical model, the process in which the underground water seepage flow function was not considered was carried on by FLAC . Fig.4 shows the vertical displacement contour-line map in this instance after multi-arch tunnel excavation. From Fig.4 it can be obviously seen that nearby the tunnel excavation region the rock deformation is relatively serious. The vault rock displacement is negative, indicating that the displacement direction is vertical downwards and subsidence occurs. But around the tunnel bottom the surrounding rock displacement is positive, indicating that the direction is vertical upwards and bulging phenomenon occurs.In the process of numerical calculation, the left and right tunnels were simulated simultaneously, namely they were excavated in the identical section plane simultaneously, that is to say, the influence of the construction order is not considered. In the computation process ofFLAC , some interesting grid points were selected to monitor their vertical displacement. The monitored grid points’ number and corresponding coordinate position are listed in Table 4.Fig.5 shows the time process curves of z-displacement (absolute value) of the monitored grid points around left tunnel vault. From Fig.5 it can be seen that the vertical displacement value(or called settlement value) of tunnel vault surrounding rock has relationship with its own position. The clos er the grid point’s position away from the tunnel excavation region, the larger the settlement value. For example, on the middle upper grid point (41 ) of left tunnel, its final calculation settlement value is 3.7 mm, and another grid poi nts’ values are getting smaller with the distance becoming longer.Fig.5 Time process curves of z-displacement of monitored grid points around le ft tunnel vault4.2 Surrounding rock deformation characteristics with underground water seepage flowThe influencing factors of surrounding rock deformation after tunnel excavation in Refs.[10−13], mainly concentrating on the grade of surrounding rock, excavating and supporting method, the neighbor construction load and the construction working procedure. Generally it almost does not consider the influence of underground water seepage flow. But in fact, the underground water existence has important influence on the surrounding rock deformation. For instance, in the excavation and tunnel engineering, the underground water seepage flow can cause quite big displacement of the soil or rock mass and even threaten the safety of engineering . In this study, some quantitative researches on the influence of surrounding rock deformation were carried out by underground water seepage flow.The stratum is fully saturated with water before tunnel is excavated. The seepage flow boundary condition includes that thepore-water pressure of the top surface is limited to zero and the two sides as well as the base boundary are water-proof boundaries . Before tunnel excavation the pore pressure of the stratum is hydro-static pressure. After tunnel excavation, around the tunnel excavation boundary is simulated by a free water seepage flow boundary where the adjacent underground water infiltrates into the excavated area. And the seepage flow field of surrounding rock has been changed with the excavation being carried on. Then the coupling analysis was executed by FLAC .Fig.6 shows the vertical displacement contour-line map after multi-arch tunnel excavation when considering the underground water seepage flow function. Obviously it can be seen that in coupling analysis the arch subsidence quantity is larger than that of not considering seepage function andthe affected region is also wider than that of the former as shown in Fig.4.Fig.6 z-displacement contour-line map of surrounding rock when considering underground water seepage flow function (unit: mm)coupling analysis, as the change of pore pressure in surrounding rock, the effective stress will be changed and it will cause the rock porosity ratio to reduce, leading to a larger arch subsidence quantity compared with that of not considering the seepage flow effect. But the vertical displacements at the bottom of the tunnel are not changed a lot. Fig.7 shows the calculated vertical displacement value for both vault’s middle position (grid point 41 and gridpoint 52 ). It can be seen that the subsidence quantity gradually increases with computation development, after finally tends to its new balance, both vault’s vertical displacement quantities finally stabilize at about 5.7 mm and the two time process curves are basically consistent.Fig.7 Curves of both vault’s node displacement vs calculation stepsFig.8 shows the time process curves of z -displacement(absolute value) of the monitored grid points around the left tunnel vault when taking the underground water seepage flow intoconsideration. Contrasting with Fig.5 it is obviously seen that the settlement value of 41 grid point is increased and reaches 5.7 mm. And to the other monitored grid points, their subsidence quantities also basically tend to 5.0 mm. The calculation subsidence quantities do not change when their relative positions changes.Fig.8 Time process curves of vault settlement when taking underground water seepage f low into consideration4.3 Comparison of deformation measurement results of surrounding rock In the process of excavating, the Bi Ma-Xi tunnel, the inspecting and consulting company of the fourth investigation and design institute of Chinese Railways Ministry monitored the surrounding rock deformation. Fig.9 shows the monitored vault settlement curves at sections K218+280 and K218+310.#Fig.9 Curves of measured value of vault settlement in process of left tunnel excavationComparing Fig.9 with Fig.5 and Fig.8, the maximal vault settlement calculation value is 3.7 mm when without considering underground water seepage flow, and when taking it into consideration the maximal calculation value is equal to 5.7 mm. And the practical monitored results reach 6.5 mm and tend to be stable after 2 months when the tunnel is excavated. The case fits very well with the coupling analysis result. The vault settlement measurement values in this multi-arch tunnel are all basically leveled off between 5.8 mm and 6.8 mm.The calculation results of coupling fluid-mechanical analysis are slightly smaller than the measured results. The reason is that the numerical calculation is thought as converged when the maximal unbalanced force in surrounding rock tends to a less value after tunnel excavation. And it does not consider the effect of actual time. The parameters in calculating unavoidably exist difference with the parameter of rock mass in reality. These reasons lead to the difference between the coupling analysis and the engineering measurement. But the results obtained in section 4.1 are less than the measuring results considering it indicates that the numerical analysis without underground water seepage flow cannot meet the need of engineering.5 Conclusions1) When underground water seepage flow function is considered in coupling fluid-mechanical analysis, the calculation vault settlements have finally achieved5.7−6.0 mm with the interaction of undergroundwater seepage flow and stress release in surrounding rock around the tunnel. The coupling calculation results are very close to the vault measurement settlement. It indicates that constructing tunnels in aquiferous stratum the underground water seepage flow effect must be considered in the design phase.2) The settlement of the surrounding rock above the tunnel has close relationship with its own position. The region near the tunnel excavation zone has the biggest rock deformation, so it should promptly complete supporting measures. When not considering the seepage flow function, the farther the region, the smaller the rock deformation; but when considering the seepage flow function, the settlement of the surrounding rock is above the tunnel and then basically tends to stable in shallower tunnel and it has obviously influence on the ground surface subsidence.地下水渗流对双连拱隧道围岩变形的影响摘要：一般来说，对于高速公路双连拱隧道，用FLAC3D计算隧道围岩变形时是没有考虑到地下水渗流影响的。

毕业设计外文资料翻译学院：信息科学与工程学院专业：软件工程姓名： XXXXX学号： XXXXXXXXX外文出处： Think In Java (用外文写)附件： 1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂，而且极易出错。

程序员必须掌握与网络有关的大量细节，有时甚至要对硬件有深刻的认识。

一般地，我们需要理解连网协议中不同的“层”（Layer）。

而且对于每个连网库，一般都包含了数量众多的函数，分别涉及信息块的连接、打包和拆包；这些块的来回运输；以及握手等等。

这是一项令人痛苦的工作。

但是，连网本身的概念并不是很难。

我们想获得位于其他地方某台机器上的信息，并把它们移到这儿；或者相反。

这与读写文件非常相似，只是文件存在于远程机器上，而且远程机器有权决定如何处理我们请求或者发送的数据。

Java最出色的一个地方就是它的“无痛苦连网”概念。

有关连网的基层细节已被尽可能地提取出去，并隐藏在JVM以及Java的本机安装系统里进行控制。

我们使用的编程模型是一个文件的模型；事实上，网络连接（一个“套接字”）已被封装到系统对象里，所以可象对其他数据流那样采用同样的方法调用。

除此以外，在我们处理另一个连网问题——同时控制多个网络连接——的时候，Java内建的多线程机制也是十分方便的。

本章将用一系列易懂的例子解释Java的连网支持。

15.1 机器的标识当然，为了分辨来自别处的一台机器，以及为了保证自己连接的是希望的那台机器，必须有一种机制能独一无二地标识出网络内的每台机器。

早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。

但Java面向的是整个因特网，这要求用一种机制对来自世界各地的机器进行标识。

为达到这个目的，我们采用了IP（互联网地址）的概念。

IP以两种形式存在着：(1) 大家最熟悉的DNS（域名服务）形式。

我自己的域名是。

所以假定我在自己的域内有一台名为Opus的计算机，它的域名就可以是。

译文交通拥堵和城市交通系统的可持续发展摘要：城市化和机动化的快速增长，通常有助于城市交通系统的发展，是经济性，环境性和社会可持续性的体现，但其结果是交通量无情增加，导致交通拥挤。

道路拥挤定价已经提出了很多次，作为一个经济措施缓解城市交通拥挤，但还没有见过在实践中广泛使用，因为道路收费的一些潜在的影响仍然不明。

本文首先回顾可持续运输系统的概念，它应该满足集体经济发展，环境保护和社会正义的目标。

然后，根据可持续交通系统的特点，使拥挤收费能够促进经济增长，环境保护和社会正义。

研究结果表明，交通拥堵收费是一个切实有效的方式，可以促进城市交通系统的可持续发展。

一、介绍城市交通是一个在世界各地的大城市迫切关注的话题。

随着中国的城市化和机动化的快速发展，交通拥堵已成为一个越来越严重的问题，造成较大的时间延迟，增加能源消耗和空气污染，减少了道路网络的可靠性。

在许多城市，交通挤塞情况被看作是经济发展的障碍。

我们可以使用多种方法来解决交通挤塞，包括新的基础设施建设，改善基础设施的维护和操作，并利用现有的基础设施，通过需求管理策略，包括定价机制，更有效地减少运输密度。

交通拥堵收费在很久以前就已提出，作为一种有效的措施，来缓解的交通挤塞情况。

交通拥堵收费的原则与目标是通过对选择在高峰拥挤时段的设施的使用实施附加收费，以纾缓拥堵情况。

转移非高峰期一些出行路线，远离拥挤的设施或高占用车辆，或完全阻止一些出行，交通拥堵收费计划将在节省时间和降低经营成本的基础上，改善空气中的质量，减少能源消耗和改善过境生产力。

此计划在世界很多国家和地方都有成功的应用。

继在20世纪70年代初和80年代中期挪威与新加坡实行收费环，在2003年2月伦敦金融城推出了面积收费;直至现在，它都是已经开始实施拥挤收费的大都市圈中一个最知名的例子。

然而，交通拥堵收费由于理论和政治的原因未能在实践中广泛使用。

道路收费的一些潜在的影响尚不清楚，和城市发展的拥塞定价可持续性，需要进一步研究。