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二 〇 一 年 月
本科毕业设计 外文文献及翻译 英文题目：Testing ZigBee Motes for Monitoring Refrigerated Vegetable Transportation under Real Conditions 中文题目：ZigBee 检测探头在冷藏蔬菜运输现实条件下的测试 学生姓名： 学 院：信息
工程学院
系 别：电子信息工程
专 业：
班 级： 指导教师： 教授
Abstract
Quality control and monitoring of perishable goods during transportation and delivery services is an increasing concern for producers, suppliers, transport decision makers and consumers. The major challenge is to ensure a continuou s …cold chain?from producer to consumer in order to guaranty prime condition of goods. In this framework, the suitability of ZigBee protocol for monitoring refrigerated transportation has been proposed by several authors. However, up to date there was not any experimental work performed under real conditions. Thus, the main objective of our experiment was to test wireless sensor motes based in the ZigBee/IEEE 802.15.4 protocol during a real shipment. The experiment was conducted in a refrigerated truck traveling through two countries (Spain and France) which means a journey of 1,051 kilometers. The paper illustrates the great potential of this type of motes, providing information about several parameters such as temperature, relative humidity, door openings and truck stops. Psychrometric charts have also been developed for improving the knowledge about water loss and condensation on the product during shipments.
1. Introduction
Perishable food products such as vegetables, fruit, meat or fish require refrigerated transportation. For all these products, Temperature (T) is the most important factor for extending shelf life, being essential to ensure that temperatures along the cold chain are adequate. However, local temperature deviations can be present in almost any transport situation. Reports from the literature indicate gradients of 5 °C or more, when deviations of only a few degrees can lead to spoiled goods and thousands of Euros in damages. A recent study shows that refrigerated shipments rise above the optimum temperature in 30% of trips from the supplier to the distribution centre, and in 15% of trips from the distribution centre to the stores. Roy et al. analyzed the supply of fresh tomato in Japan and quantified product losses of 5% during transportation and distribution. Thermal variations during transoceanic shipments have also been studied. The results showed that there was a significant temperature variability both spatially across the width of the container as well as temporally along the trip, and that it was out of the specification more than 30% of the time. In those experiments monitoring was achieved by means of the installation of hundreds of wired sensors in a single container, which makes this system architecture commercially unfeasible.
Transport is often done by refrigerated road vehicles and containers equipped with embedded cooling systems. In such environments, temperatures rise very quickly if a reefer unit fails. Commercial systems are presently available for monitoring containers and trucks, but they do not give complete information about the cargo, because they typically measure only temperature and at just one point.
Apart from temperature, water loss is one of the main causes of deterioration that reduces the marketability of perishable food products. Transpiration is the loss of moisture from living tissues. Most weight loss of stored fruit is caused by this process. Relative humidity (RH), T of the product, T of the surrounding atmosphere, and air velocity all affect the amount of water lost in food commodities. Free water or condensation is also a problem as it encourages microbial infection and growth, and it can also reduce the strength of packaging materials.
Parties involved need better quality assurance methods to satisfy customer demands and
to create a competitive point of difference. Successful transport in food logistics calls for automated and efficient monitoring and control of shipments. The challenge is to ensure a continuous …cold chain? from producer to consumer in order to guaranty prime condition of goods .
The use of wireless sensors in refrigerated vehicles was proposed by Qingshan et al. as a new way of monitoring. Specialized WSN (Wireless Sensor Network) monitoring devices promise to revolutionize the shipping and handling of a wide range of perishable products giving suppliers and distributors continuous and accurate readings throughout the distribution process. In this framework, ZigBee was developed as a very promising WSN protocol due to its low energy consumption and advanced network capabilities. Its potential for monitoring the cold chain has been addressed by several authors but without real experimentation, only theoretical approaches. For this reason, in our work real experimentation with the aim of exploring the limits of this technology was a priority.
The main objective of this project is to explore the potential of wireless ZigBee/IEEE 802.15.4 motes for their application in commercial refrigerated shipments by road. A secondary objective was to improve the knowledge about the conditions that affect the perishable food products during transportation, through the study of relevant parameters like temperature, relative humidity, light, shocking and psychrometric properties.
2. Materials and Methods
2.1. ZigBee Motes
Four ZigBee/IEEE 802.15.4 motes (transmitters) and one base station (receiver) were used. All of them were manufactured by Crossbow. The motes consist of a microcontroller board (Micaz) together with an independent transducer board (MTS400) attached by means of a 52 pin connector. The Micaz mote hosts an Atmel ATMEGA103/128L CPU running the Tiny Operating System (TinyOS) that enables it to execute programs developed using the nesC language. The Micaz has a radio device Chipcon CC2420 2.4 GHz 250 Kbps IEEE 802.15.4. Power is supplied by two AA lithium batteries.
The transducer board hosts a variety of sensors: T and RH (Sensirion SHT11), T and barometric pressure (Intersema MS5534B), light intensity (TAOS TSL2550D) and a two-axis accelerometer (ADXL202JE). A laptop computer is used as the receiver, and communicates with the nodes through a Micaz mounted on the MIB520 ZigBee/USB gateway board.
Each Sensirion SHT11 is individually calibrated in a precision humidity chamber. The calibration coefficients are used internally during measurements to calibrate the signals from the sensors. The accuracies for T and RH are ±0.5 °C (at 25 °C) and ±3.5% respectively.
The Intersema MS5534B is a SMD-hybrid device that includes a piezoresistive pressure sensor and an ADC-Interface IC. It provides a 16 bit data word from a pressure and T (?40 to +125°C) dependent voltage. Additionally the module contains six readable coefficients for a highly accurate software calibration of the sensor.
The TSL2550 is a digital-output light sensor with a two-wire, SMBus serial interface. It combines two photodiodes and an analog-to digital converter (ADC) on a single CMOS integrated circuit to provide light measurements over a 12-bit dynamic range. The ADXL202E measures accelerations with a full-scale range of ±2 g. The ADXL202E can measure both dynamic acceleration (e.g., vibration) and static acceleration (e.g., gravity).
2.2. Experimental Set Up
The experiment was conducted in a refrigerated truck traveling during 23 h 41 m 21 s from Murcia (Spain) to Avignon (France), a distance of 1,051 km. The truck transported approx.14,000 kg of lettuce var. Little Gem in 28 pallets of 1,000 × 1,200 mm . The lettuce was packed in cardboard boxes with openings for air circulation.
The length of the semi-trailer was 15 m with a Carrier Vector 1800 refrigeration unit mounted to the front of the semi-trailer. For this shipment the set point was 0 °C.
The truck was outfitted with the wireless system, covering different heights and lengths from the cooling equipment, which was at the front of the semi-trailer. Four motes were mounted with the cargo (see Figure 1): mote 1 was at the bottom of the pallets in the front side of the semi-trailer, mote 2 was in the middle of the semi-trailer, mote 3 was in the rear at the top of the pallet, and mote 4 was located as shown in Figure 1, about a third of the distance between the front and the rear of the trailer. Motes 1, 2 and 3 were inside the boxes beside the lettuce. The program installed in the motes collects data from all the sensors at a fixed sample rate (7.2 s), with each transmission referred to as a “packet”. The RF power in the Micaz can be set from ?24 dBm to 0 dBm. During the experiment, the RF power was set to the maximum, 0dBm (1mW approximately).
2.3. Data Analysis
A specialized MATLA
B program has been developed for assessing the percentage of lost packets (%) in transmission, by means of computing the number of multiple sending failures for a given sample rate (SR). A multiple failure of m messages occurs whenever the elapsed time between two messages lies between 1.5 ×m ×SR and 2.5 ×m ×SR. For example, with a sample rate of 11 s, a single failure (m = 1) occurs whenever the time period between consecutives packets is longer than 16.5 s (1.5 × 1 × 11) and shorter than 27.5 s (2.5 × 1 × 11). The total number of lost packets is computed based on the frequency of each failure type. Accordingly, the total percentage of lost packets is calculated as the ratio between the total number of lost packets and the number of sent packets.
The standard error (SE) associated to the ratio of lost packets is computed based on a binomial distribution as expressed in Equation 1, where n is the total number of packets sent, and p is the ratio of lost packets in the experiment.
2.4. Analysis of Variance
Factorial Analysis of Variance (ANOV A) was performed in order to evaluate the effect of the type of sensor in the registered measurements, including T (by means of Sensirion and Intersema), RH, barometric pressure, light intensity and acceleration module. ANOV A allows partitioning of the observed variance into components due to different explanatory variables. The STATISTICA software (StatSoft, Inc.) was used for this purpose [14]. The Fishers?s F ratio compares the variance within sample groups (“inherent variance”) with the variance between groups (factors). We use this statistic for knowing which factor has more influence in the variability of the measurements.
2.5. Psychrometric Data
Psychrometry studies the thermodynamic properties of moist air and the use of these properties to analyze conditions and processes involving moist air. Psychrometric charts
show a graphical representation of the relationship between T, RH and water vapor pressure
in moist air. They can be used for the detection of water loss and condensation over the product.
In our study, the ASAE standard D271.2 was used for computing the psychrometric properties of air. Equations 2–5 and Table 1 enable the calculation of all psychrometric data of air whenever two independent psychrometric properties of an air-water vapour mixture are known in addition to the atmospheric pressure:where Ps stands for saturation vapor pressure (Pa), T is the temperature (K), Pv is the vapor pressure (Pa), H the absolute humidity (g/kg dry air), Patm is atmospheric pressure (Pa) and A, B, C, D, E, F, G and R are a series of coefficients used to compute Ps, according to Equation 3.
3.Results and Discussion
3.1. Reliability of Transmission
Signal propagation through the lettuce lead to absorption of radio signals, resulting in great attenuations in RF signal strength and link quality at the receiver. During the experiment, only motes 3 and 4 were able to transmit to the coordinator. No signals were received from mote number 1, at the bottom of the first pallet, and number 2, in the middle of the pallet. Mote 3 was closer to the coordinator than mote 4, but mote 3 was surrounded by lettuce which blocks the RF signal. However between mote 4 and the coordinator there was free space for transmission. Thus, the maximum ratio of lost packets found was 100% for two of the motes and the minimum 4.5% ± 0.1%, for mote 4.
Similar ratios were reported by several authors who performed experiments with WSN under real conditions, like for example in monitoring vineyards. Also, Baggio and Haneveld, after one year of experimentation in a potato field using motes operating at the band of 868/916MHz, reported that 98% of data packets were lost. However, during the second year the total amount of data gathered was 51%, which represents a clear improvement. Ipema et al. monitored cows with Crossbow motes, and found that the base station directly received less than 50% of temperature measurements stored in the mote buffer. Nadimi et al., who also monitored cows with this type of motes, showed packet loss rates of about 25% for wireless sensor data from cows in a pasture even the distance to the receiver (gateway) was less than 12.5 m away.
Radio propagation can be influenced by two main factors: the properties of propagation media and the heterogeneous properties of devices. In a commercial shipment, if the motes are embedded within the cargo, a significant portion of the Fresnel zone is obstructed. This is a big challenge in our application. Changing the motes? location, for example the one at the bottom of the pallets (mote 1, at the front of the semitrailer) or the one in the middle of the compartment (mote 2), might have yielded in better data reception rates but would have resulted in a loss of spatial information near the floor or at mid-height. The sensors should be as close as possible to the products transported; otherwise the measurements would not give precise information. Thus, one solution, if the same motes are to be used, could be to include
intermediates motes that allow peer to peer communication to the base station. Another solution could be to use lower frequencies; however this is not possible using ZigBee, because the only radio frequency band available for ZigBee worldwide is the 2.4 GHz one. The other ISM (Industrial, Scientific and Medical) bands (868 MHz and 915 MHz) differ from USA to Europe. Other options include developing motes with more RF power that can achieve longer radio ranges. The transmission could also be improved by optimizing antenna orientation, shape and configuration. The standard antenna mounted in the Micaz is a 3 cm long 1/2 wavelength dipole antenna. The communications could be enhanced using ceramic collinear antennas or with use of a simple reflecting screen to supplement a primary antenna, which can provide a 9dB improvement. Link asymmetry and an irregular radio range can be caused by the antenna position. In a real environment, the pattern of radio transmitted at the antenna is neither a circular nor a spherical shape. Radio irregularity affects the motes performance and degrades their ability to maintain connection to other nodes in the network. However, in our experiment Micaz motes were deployed in its best position according to a recent study. Another issue is the received signal strength indicator (RSSI), it should be recorded in further experiments in order to detect network problems and estimate the radio link quality. RSSI is a way for the radio to report the strength of the radio signal that it is receiving from the transmitting unit.
Sample rates configured in the motes were very short in order to get the maximum amount of data about the ambient conditions. In practice, a reduction in the sampling frequency of recording and transmission should be configured in order to extend battery life. According to Thiemjarus and Yang this also provides opportunities for data reduction at the mote level. It is expected that future wireless sensor motes will have on-board features to analyze recorded data and detect certain deviations. The level of a deviation determines whether the recording or transmitting frequency should be adapted .
One important feature in the motes came from the miniaturized sensors mounted on the motes that allow, in a small space (2.5 ×5 ×5 cm), to provide data not just about temperature, but also RH, acceleration and light, according to the proposal of Wang and Li. Those variables were also measured and analyzed.
3.2. Transport Conditions
For the analysis of T conditions, the average value of the two sensors mounted in each mote is considered. The set-point of the transport trailer?s cooling system was 0 °C, but the average temperature registered during the shipment was 5.33 °C, with a maximum of 8.52 °C and a minimum of ?3.0 °C. On average, 98% of the time the temperature was outside of the industry recommended range (set-point ± 0.5 °C).
Figure 2 shows the temperature fluctuations registered during the shipment, where four different markers are used corresponding to two T sensors per mote. There are large differences between the temperatures recorded with each sensor on the same mote even thought individual calibration curves were used. The SHT11 measures consistently higher temperatures than the Intersema. This behaviour could be due to the closer location of the SHT11 to the microcontroller, causing sensor self-heating effects.
In other studies, like for example Tanner and Amos, it was observed that the cargo was within the industry recommended T interval for approximately 58% of the shipment duration. Rodriguez-Bermejo et al. compared two different cooling modes in a 20? reefer container. For modulated cooling the percentage of time within the recommendation ranged between 44% and 52% of the shipment duration, whereas for off/on control cooling it ranged between 9.6% and 0%. In those experiments, lower percentages of time within industry recommended intervals are found for high T set points.
The analysis of variance of the T data shows that the variability in temperature depended both in the type of sensor and on the mote used. The interaction between these two factors also has an impact on the T measurements. The critical value of F at 95% probability level is much lower than the observed values of F, which means that the null hypothesis is false. The mote is the factor that has most influence on the variability of the measurements (highest Fishers?s F); this fact seems to be due to the location of the node. Mote 4 is closer to the cooling equipment which results in lower temperature measurements.
The node is a very significant factor in the measurements registered. In the case of RH, pressure, light and acceleration, the node location has great influence in data variability . However, node location has more impact on the measured RH than on the other variables.
Inside the semi-trailer RH ranged from 55 to 95% (see Figure 3). The optimal RH for
lettuce is 95%. Humidity was always higher at mote 4 (at the top middle of the semi-trailer; average RH 74.9%) than at mote 3 (located at the rear; average RH 62.1%).
摘要
生产商、供应商、运输决策者和消费者越来越关心易腐货物在运输和交付服务中对质量的掌握和把控。最大的挑战是确保从生产商到消费者持续的“冷链”以保证货物。在这个框架内，几位作者提出用于监测冷藏运输ZigBee协议的适用性。然而，到目前为止没有任何真实条件下进行的实验工作。因此，我们实验的主要目的是测试基于ZigBee / IEEE 802.15.4协议的无线传感器在实际装运中的应用。本次实验是一辆穿过两个国家（法国和西班牙）的冷藏车的一个1051公里的旅程。本文阐述了这种类型的传感器的巨大潜力，提供信息的几个参数，如温度，相对湿度，门洞口停车等。焓湿图也被开发，提高对产品在运输和冷凝水损失知识的了解。
关键词：ZigBee；无线传感；冷链物流；食品
1 介绍
蔬菜，水果，肉类或鱼这些易腐蚀食品需要冷藏运输。对于这些产品延长保质期，以确保冷链保持足够长的温度（T）是必不可少的。然而，局部温度偏差会出现在大部分的运输情况中。从文献报告显示梯度为5°C以上时，只要温度存在几度的偏差，就可能会导致商品的腐蚀和数千欧元的赔偿。最近的一项研究表明，从供应商到配送中心的车次冷藏运输的温度会上升30％以，而从配送中心到门店的则上升15％。Roy et al分析了，在日本供应新鲜的西红柿在运输和分配时会给产品带来5％亏损，对远洋运输的温度变化也进行了研究。结果表明，整个容器的宽度随着时间而逐渐上升，并超过标准时间的30％，所以存在显着的温度变化。在这些实验中，在一个容器里安装了数百个监测有线传感器的装置，这样的系统架构是不可能实现的。
在冷藏公路车辆和集装箱运输中会配备嵌入式冷却系统，在这样的环境中，如果冷藏系统发生故障会导致温度上升的速度非常快。商业系统主要应用于检测集装箱和卡车中，由于它们仅仅测量一个点的温度，所以他们给不出货物的完整信息。
除了温度的影响，水分的流失也是导致食物易腐烂的主要原因之一。蒸腾作用使水分子大量的流失，这个过程被称为水果减肥。相对湿度、大气周围的温度和空气的流速都会影响食品水分的流失。通过冷凝方式减少水分的流失，这样不仅促进了微生物的生长，同时也减少了材料的包装。
参与各方需要严格的保证产品质量，以满足客户的需求。成功的运输需要食品在运输过程中具有有效的监测和控制出货量的能力。其挑战是从生产者到消费者保持持续的冷链状态，从而保证货物的质量。
青山等人提出在冷藏车使用无线传感器这种新的监控方式。专业WSN监控设备改变了易腐蚀产品，给供应商和分销商在整个分销过程中提供了连续且又准确读数范围的运输和装载能力。由于ZigBee技术其能耗低和先进的网络功能的特点，已成为现在非常有前途的无线传感器网络协议。其冷链监测能力虽然有效，但没有进行的实验，出于这个原因，我们工作的目的是探索这项技术的优势。
这个项目的主要目的发掘ZigBee / IEEE 802.15.4无线技术，为他们在商业冷藏运输公路上的应用。第二个目标是改善其条件，通过学习相关的参数，如温度，相对湿度，光照等性能，了解易腐食品在运输过程中的知识。
2 材料和方式
2.1 ZigBee技术
应用四个ZigBee / IEEE 802.15.4微尘（发射器）和一个基站（接收器）。微尘由一个微控制器板（Micaz）和一个具有52针连接器独立连接的传感器板（MTS400）组成。Micaz微尘主板是爱特梅尔ATMEGA103/128L CPU处理器，使执行程序使用的是TinyOS微型操作系统开发的nesC语言。Micaz是Chipcon公司的IEEE 802.15.4无线电设备具有CC2420 2.4 GHz和250 Kbps其电源由两节AA锂电池构成。
传感器主板承载了各种传感器：温度和相对湿度（SHT11 Sensirion的），T和气压（MS5534B INTERSEMA）的，光强度（TAOS TSL2550D）的两轴加速度计（ADXL202JE）。一台笔记本电脑被用作接收器，MIB520的ZigBee / USB网关板安装在Micaz上并与各个节点进行通信。
每个经过SENSIRION SHT11单独校准精确的湿度室。在测量过程中，在内部使用校准系数来校准来自传感器的信号。温度和相对湿度的精度为±0.5°C（25°C）和±3.5％。
INTERSEMA MS5534B是SMD的一个特殊装置，其包括一个电阻压力传感器和一个ADC，IC接口。它提供了一个16位数据字。此外，该模块包含了一个六位可读系数的高度精确的软件传感器。
TSL2550是一个具有两线SMBus串行接口的数字输出光传感器。它结合了两个光电二极管和一个模拟到数字转换器（ADC），在一个单一的CMOS集成电路中提供一个12位的动态范围的光测量。ADXL202E可以测量动态加速度（如振动）和静态加速度（如重力）其测量加速度的满程范围为±2克。
2.2实验装置
实验进行23小时41分钟21秒冷藏卡车行驶从穆尔西亚（西班牙）到阿维尼（法国）1,051公里的距离。卡车运送约14，000公斤生菜V AR。28托盘1,000×1,200毫米的小宝石。生菜用开口的纸板箱包装以便空气流通。
拖车的长度为15米，载有其1800的制冷单元，其被安装到拖车的前部。对于这批货物把温度集中控制到0℃。
在拖车中配备了无线系统，在拖车的前部配备了冷却设备，具有不同的高度和长度。四微尘搭载货物（参见图1）：1指的半拖车的前侧且的底部，2在半拖车的中间，3是在后方的托板上，4在半拖车顶部大约占拖车的前部和后部之间三分之一的距离。
1，2和3里面的箱子里装有生菜。该程序安装在一个固定的采样率（7.2）传感器中，每次传输被称为一个“数据包”。Micaz的RF功率可以设置从-24 dBm至0 dBm。在实验过程中，RF功率被设置到最大，为0dBm（1mW的约数）。
图1 实验装置侧面图和俯视图
2.4方差分析
方差分析（ANOV A）时，以评估不同的传感器的的测量，包括T（由装置Sensirion 的INTERSEMA的），相对湿度，气压，光强度和加速模块的效果。方差分析允许所观察划分成组件。STA TISTICA软件（StatSoft推出，公司）被用于此项研究。渔民“F比比较样本组内变异（”内在差异“）组（因素）之间的差异。我们知道哪些因素具有更大的影响力对此进行统计。
2.5湿度分析
湿度测定法研究了湿空气的热力学性质，这些性质的使用的分析条件和过程涉及的潮湿的空气。焓湿图显示之间的关系的图形表示，相对湿度和水蒸汽压在潮湿的空
气中。它们可用于在产品水分的损失和凝结的检测。
第三章结果与讨论
3.1 传输的可靠性
通过接收生菜信号的无线电信号，发现在射频信号强度和接收机的链路质量有很大的衰减。在实验过程中，只有3号和4号传感器能够传递给协调器。在盘的底部遥控接收的1号和在托盘中间的2号没有信号。传感器3比4更靠近协调器，但传感器3的射频信号被生菜块包围。然而传感器4和协调器有自由传输空间。因此丢失的数据包的最大比值在100%和误差在4.5%±0.1%。
类似的比率是由几位作者进行真实条件下的无线传感器网络实验报告中出现的，例如在监测葡萄园。就像Baggio和Haneveld的实验，在一年内将在868 / 916MHZ 波段操作的传感器在土豆田里使用，依报告显示数据包丢失了98%。然而，在第二年的总采集数据量为51%，这是一个明显的改进。Ipema等也是如此。监测奶牛中传感器，并发现基站直接得到小于温度测量，存储在缓冲区50%粒。Nadimi等也是这样。谁还监测奶牛这种类型的传感器，显示关于无线传感器数据从奶牛在牧场甚至到接收机的距离25%的数据包丢失率即网关小于12.5米的距离。
无线电波的传播可以通过两个主要因素的影响：传播媒体的特性和设备的异构特性。在一个商业装运，如果微粒嵌入在货物，菲涅耳带的很大一部分被阻塞。这是在我国应用的一大挑战。改变微尘?位置，例如在托盘底部的一个（节点1，在半挂车前）或一个在车厢的中部（节点2），可能会产生更好的数据接收速率，但会导致的损失的空间信息在地板上或在中等身高。传感器应尽量接近成品运输；否则，将不提供精确的信息。因此，一个解决方案，如果同样的尘埃被使用，可能包括中间体微尘，允许对等通信的基站。另一个解决方案是使用频率较低；然而这是不可能使用ZigBee ZigBee，因为用于全球唯一的广播频率是2.4 GHz的一个。其他的ISM（工业，科学和医疗）频段（868兆赫和915兆赫）不同，从美国到欧洲。其他选项包括发展更多的射频功率，可以实现更长的无线电范围内的尘埃。传输也可以通过优化天线的方向改进，形状和结构。安装在MicaZ标准天线是一个3厘米长的1／2波长的偶极子天线。通讯可以采用陶瓷共线天线或使用的增强简单的反射屏补充主天线，它可以提供一个9dB的改进。链路的不对称性和不规则的无线电范围可以由天线位置引起的。在实际环境中，无线发送天线模式既不圆也不是一个球形的形状。无线电不规则影响的微尘的性能和降低他们维持到网络中的其他节点的连接能力。然而，根据最近的一项研究在我们的实验MicaZ节点被部署在最好的位置。另一个问题是所接收的信号强度指示器（RSSI），它应该被记录下来，在进一步的实验来检测网络的问题和估计的无
线链路质量。RSSI的无线电报告的无线电信号的强度，它接收从发送单元的方法。
采样率配置在尘埃非常短，为了获得对环境条件的最大数据量。在实践中，在记录和传输的采样频率减少的配置应以延长电池寿命。根据Thiemjarus这也提供了在尘埃层数据的减排机会。预计未来无线传感器微尘会上的特征来分析记录的数据和检测到一定的偏差。一个偏差水平决定的记录或传输频率。
在Motes的一个重要特征是从小型化的传感器安装在微尘，允许，在一个小空间（2.5×5×5厘米），提供的数据不只是温度，而且RH，加速和光，根据王、李[ 30 ]的建议。进行测量和分析这些变量。
3.2 运输条件
对条件的分析，对两个传感器安装在每个节点的平均值是。对运输拖车?冷却系统的设定点为0°C，但在装运注册的平均温度是5.33°C，最多的有8.52°C和最小的?3°C.平均温度的，是业内外的时间98%推荐的范围（设定点±0.5°C）。
图2显示了在装运中注册的温度波动，在四个不同的标记是用对应于每两个传感器微尘。有记录的每个传感器在相同的尘埃温度之间的大的差异，甚至认为是个人的校准曲线。SHT11措施比intersema始终保持较高的温度。这种行为可能是由于该SHT11的接近的位置控制器，使传感器的自加热效应。
在其他的研究中，例如Tanner和阿摩司，发现货物在行业推荐的大约58%的出货时间 T间期。罗德里格兹贝尔梅霍等。比较了两种不同的冷却方式在20?冷藏集装箱。调制在推荐的冷却时间的百分比范围的装运时间44%和52%之间，而打开/关闭的控制冷却，在9.6%和0%之间。在这些实验中，较低的百分比的时间间隔内的行业推荐发现高T设定点。
对数据的方差分析表明，在温度的变化取决于在传感器的类型和使用的微粒。这两个因素之间的相互作用还对T测量的影响。在95%的概率水平下的临界值比F观测值低得多，这意味着零假设是错误的。这本书已在测量的变异最影响因素（最高的渔民?S F）；这一事实似乎是由于节点的位置。4是在较低的温度测量更接近冷却设备，结果。
节点注册测量的一个重要因素。在RH，压力的情况下，光和加速度，节点的位置在数据变异性很大的影响。然而，节点位置对测量相对湿度的影响较其他变量。
在半挂车RH的范围从55到95%。生菜最佳相对湿度95%。湿度总是高于在点4（在半挂车；顶部中间的平均相对湿度74.9%）比在点3（位于后部；平均相对湿度
62.1%）。
外文出处： 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题： JDBC接口技术 译文： JDBC是一种可用于执行SQL语句的JavaAPI（ApplicationProgrammingInterface应用程序设计接口）。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口，使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC，很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢？如果有，那么它们之间又是怎样的关系呢？ ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统（DBMS）中存取数据的，用C语言实现的，标准应用程序数据接口。通过ODBCAPI，应用程序可以存取保存在多种不同数据库管理系统（DBMS）中的数据，而不论每个DBMS使用了何种数据存储格式和编程接口。 1．ODBC的结构模型 ODBC的结构包括四个主要部分：应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口：屏蔽不同的ODBC数据库驱动器之间函数调用的差别，为用户提供统一的SQL编程接口。 驱动器管理器：为应用程序装载数据库驱动器。 数据库驱动器：实现ODBC的函数调用，提供对特定数据源的SQL请求。如果需要，数据库驱动器将修改应用程序的请求，使得请求符合相关的DBMS所支持的文法。 数据源：由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器，以便ODBC函数调用，但是数据库驱动器本身也执行ODBC函数调用，并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时，数据库驱动器能管理通信协议。当建立起与数据源的连接时，数据库驱动器便能处理应用系统向DBMS发出的请求，对分析或发自数据源的设计进行必要的翻译，并将结果返回给应用系统。 2．JDBC的诞生 自从Java语言于1995年5月正式公布以来，Java风靡全球。出现大量的用java语言编写的程序，其中也包括数据库应用程序。由于没有一个Java语言的API，编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥，比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱，越来越多的公司在Java程序开发上投入的精力日益增加，对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处，比如它并不容易使用，没有面向对象的特性等等，SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1．x 版本中，JDBC只是一个可选部件，到了JDK1．1公布时，SQL类包（也就是JDBCAPI）
机械设计 摘要：机器是由机械装置和其它组件组成的。它是一种用来转换或传递能量的装置，例如：发动机、涡轮机、车辆、起重机、印刷机、洗衣机、照相机和摄影机等。许多原则和设计方法不但适用于机器的设计，也适用于非机器的设计。术语中的“机械装置设计”的含义要比“机械设计”的含义更为广泛一些，机械装置设计包括机械设计。在分析运动及设计结构时，要把产品外型以及以后的保养也要考虑在机械设计中。在机械工程领域中，以及其它工程领域中，所有这些都需要机械设备，比如：开关、凸轮、阀门、船舶以及搅拌机等。 关键词：设计流程设计规则机械设计 设计流程 设计开始之前就要想到机器的实际性，现存的机器需要在耐用性、效率、重量、速度，或者成本上得到改善。新的机器必需具有以前机器所能执行的功能。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不要受到任何约束。即使产生了许多不切实际的想法，也会在设计的早期，即在绘制图纸之前被改正掉。只有这样，才不致于阻断创新的思路。通常,还要提出几套设计方案，然后加以比较。很有可能在这个计划最后决定中,使用了某些不在计划之内的一些设想。 一般的当外型特点和组件部分的尺寸特点分析得透彻时，就可以全面的设计和分析。接着还要客观的分析机器性能的优越性，以及它的安全、重量、耐用性，并且竞争力的成本也要考虑在分析结果之内。每一个至关重要的部分要优化它的比例和尺寸，同时也要保持与其它组成部分相协调。 也要选择原材料和处理原材料的方法。通过力学原理来分析和实现这些重要的特性，如那些静态反应的能量和摩擦力的最佳利用，像动力惯性、加速动力和能量；包括弹性材料的强度、应力和刚度等材料的物理特性，以及流体润滑和驱动器的流体力学。设计的过程是重复和合作的过程，无论是正式或非正式的进行，对设计者来说每个阶段都很重要。 最后，以图样为设计的标准，并建立将来的模型。如果它的测试是符合事先要
I / 11 本科毕业设计外文翻译 <2018届） 论文题目基于WEB 的J2EE 的信息系统的方法研究 作者姓名[单击此处输入姓名] 指导教师[单击此处输入姓名] 学科(专业 > 所在学院计算机科学与技术学院 提交日期[时间 ]
基于WEB的J2EE的信息系统的方法研究 摘要：本文介绍基于工程的Java开发框架背后的概念，并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复，而且并不总是符合最佳实践，所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式，代表有效解决办法的工具。开发框架提供：<1）从用户界面到数据集成的应用程序开发堆栈；<2）一个架构，基本环境及他们的相关技术，这些技术用来使用其他一些框架。架构定义了一个开发方法，其目的是协助客户开发工程。 关键词：J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台，以实现他们的用户界面，科学分析，分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此，WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平，使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下，开源框架没有提供常见问题的一个解决方案。出于这个原因，开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架，该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架，本文提出了新的架构，基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法，其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求，也
文献综述 建筑设计参考文献综述： [1]《房屋建筑学》，邢双军主编 建筑学作为一门内容广泛的综合性学科，它沙及到建筑功能、工程技术、建筑经济、建筑艺术以及环境规划等许多方面的问题。般说来，建筑物既是物质产品，又具有一定的艺术形象，它必然随着社会生产生活方式的发展变化而发展变化，并且总是受科学技术、政治经济和文化传统的深刻影响*建筑物—一作为人们亲手创造的人为环境的重要组成部分，需要耗用大量的人力和物力。它除了具行满足物质功能的使用要求外，其空间组合和建筑形象又常会赋予人们以精神上的感受。 [2]《建筑设计防火规范》（GB50016-2006） 1.0.1 为了防止和减少建筑火灾危害，保护人身和财产安全，制定本规范。 1.0.2 本规范适用于下列新建、扩建和改建的建筑： 1 9层及9层以下的居住建筑（包括设置商业服务网点的居住建筑）； 2 建筑高度小于等于24.0m 的公共建筑； 3 建筑高度大于24.0m 的单层公共建筑； 4 地下、半地下建筑（包括建筑附属的地下室、半地下室）； 5 厂房； 6 仓库； 7 甲、乙、丙类液体储罐（区）； 8 可燃、助燃气体储罐（区）； 9 可燃材料堆场； 10 城市交通隧道。 注：1 建筑高度的计算：当为坡屋面时，应为建筑物室外设计地面到其檐口的高度；当为平屋面（包括有女儿墙 的平屋面）时，应为建筑物室外设计地面到其屋面面层的高度；当同一座建筑物有多种屋面形式时，建筑 高度应按上述方法分别计算后取其中最大值。局部突出屋顶的瞭望塔、冷却塔、水箱间、微波天线间或设 施、电梯机房、排风和排烟机房以及楼梯出口小间等，可不计入建筑高度内。 2 建筑层数的计算：建筑的地下室、半地下室的顶板面高出室外设计地面的高度小于等 于 1.5m 者，建筑底部设置的高度不超过2.2m 的自行车库、储藏室、敞开空间，以及建筑屋顶上突出的局部设备用房、出屋面 的楼梯间等，可不计入建筑层数内。住宅顶部为两层一套的跃层，可按1 层计，其它部位的跃层以及顶部 多于2 层一套的跃层，应计入层数。 1.0.3 本规范不适用于炸药厂房（仓库）、花炮厂房（仓库）的建筑防火设计。 人民防空工程、石油和天然气工程、石油化工企业、火力发电厂与变电站等的建筑防火设计，当有专门的国家现行标准时，宜从其规定。 1.0.4 建筑防火设计应遵循国家的有关方针政策，从全局出发，统筹兼顾，做到安全适用、技术先进、经济合理。 1.0.5 建筑防火设计除应符合本规范的规定外，尚应符合国家现行有关标准的规定。
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
(文档含英文原文和中文翻译) 中英文翻译 平面设计 任何时期平面设计可以参照一些艺术和专业学科侧重于视觉传达和介绍。采用多种方式相结合，创造和符号，图像和语句创建一个代表性的想法和信息。平面设计师可以使用印刷，视觉艺术和排版技术产生的最终结果。平面设计常常提到的进程，其中沟通是创造和产品设计。 共同使用的平面设计包括杂志，广告，产品包装和网页设计。例如，可能包括产品包装的标志或其他艺术作品，举办文字和纯粹的设计元素，如形状和颜色统一件。组成的一个最重要的特点，尤其是平面设计在使用前现有材料或不同的元素。 平面设计涵盖了人类历史上诸多领域，在此漫长的历史和在相对最近爆炸视觉传达中的第20和21世纪，人们有时是模糊的区别和重叠的广告艺术，平面设计和美术。毕竟，他们有着许多相同的内容，理论，原则，做法和语言，有时同样的客人或客户。广告艺术的最终目标是出售的商品和服务。在平面
设计，“其实质是使以信息，形成以思想，言论和感觉的经验”。 在唐朝（ 618-906 ）之间的第4和第7世纪的木块被切断打印纺织品和后重现佛典。阿藏印在868是已知最早的印刷书籍。 在19世纪后期欧洲，尤其是在英国，平面设计开始以独立的运动从美术中分离出来。蒙德里安称为父亲的图形设计。他是一个很好的艺术家，但是他在现代广告中利用现代电网系统在广告、印刷和网络布局网格。 于1849年，在大不列颠亨利科尔成为的主要力量之一在设计教育界，该国政府通告设计在杂志设计和制造的重要性。他组织了大型的展览作为庆祝现代工业技术和维多利亚式的设计。 从1892年至1896年威廉?莫里斯凯尔姆斯科特出版社出版的书籍的一些最重要的平面设计产品和工艺美术运动，并提出了一个非常赚钱的商机就是出版伟大文本论的图书并以高价出售给富人。莫里斯证明了市场的存在使平面设计在他们自己拥有的权利，并帮助开拓者从生产和美术分离设计。这历史相对论是，然而，重要的，因为它为第一次重大的反应对于十九世纪的陈旧的平面设计。莫里斯的工作，以及与其他私营新闻运动，直接影响新艺术风格和间接负责20世纪初非专业性平面设计的事态发展。 谁创造了最初的“平面设计”似乎存在争议。这被归因于英国的设计师和大学教授Richard Guyatt，但另一消息来源于20世纪初美国图书设计师William Addison Dwiggins。 伦敦地铁的标志设计是爱德华约翰斯顿于1916年设计的一个经典的现代而且使用了系统字体设计。 在20世纪20年代，苏联的建构主义应用于“智能生产”在不同领域的生产。个性化的运动艺术在俄罗斯大革命是没有价值的，从而走向以创造物体的功利为目的。他们设计的建筑、剧院集、海报、面料、服装、家具、徽标、菜单等。 Jan Tschichold 在他的1928年书中编纂了新的现代印刷原则，他后来否认他在这本书的法西斯主义哲学主张，但它仍然是非常有影响力。 Tschichold ，包豪斯印刷专家如赫伯特拜耳和拉斯洛莫霍伊一纳吉，和El Lissitzky 是平面设计之父都被我们今天所知。 他们首创的生产技术和文体设备，主要用于整个二十世纪。随后的几年看到平面设计在现代风格获得广泛的接受和应用。第二次世界大战结束后，美国经济的建立更需要平面设计，主要是广告和包装等。移居国外的德国包豪斯设计学院于1937年到芝加哥带来了“大规模生产”极简到美国;引发野火的“现代”建筑和设计。值得注意的名称世纪中叶现代设计包括阿德里安Frutiger ，设计师和Frutiger字体大学;保兰德，从20世纪30年代后期，直到他去世于1996年，采取的原则和适用包豪斯他们受欢迎的广告和标志设计，帮助创造一个独特的办法，美国的欧洲简约而成为一个主要的先驱。平面设计称为企业形象;约瑟夫米勒，罗克曼，设计的海报严重尚未获取1950年代和1960年代时代典型。 从道路标志到技术图表，从备忘录到参考手册，增强了平面设计的知识转让。可读性增强了文字的视觉效果。 设计还可以通过理念或有效的视觉传播帮助销售产品。将它应用到产品和公司识别系统的要素像标志、颜色和文字。连同这些被定义为品牌。品牌已日益成为重要的提供的服务范围，许多平面设计师，企业形象和条件往往是同时交替使用。
Section 3 Design philosophy, design method and earth pressures 3.1 Design philosophy 3.1.1 General The design of earth retaining structures requires consideration of the interaction between the ground and the structure. It requires the performance of two sets of calculations: 1）a set of equilibrium calculations to determine the overall proportions and the geometry of the structure necessary to achieve equilibrium under the relevant earth pressures and forces; 2）structural design calculations to determine the size and properties of thestructural sections necessary to resist the bending moments and shear forces determined from the equilibrium calculations. Both sets of calculations are carried out for specific design situations (see 3.2.2) in accordance with the principles of limit state design. The selected design situations should be sufficiently Severe and varied so as to encompass all reasonable conditions which can be foreseen during the period of construction and the life of the retaining wall. 3.1.2 Limit state design This code of practice adopts the philosophy of limit state design. This philosophy does not impose upon the designer any special requirements as to the manner in which the safety and stability of the retaining wall may be achieved, whether by overall factors of safety, or partial factors of safety, or by other measures. Limit states (see 1.3.13) are classified into: a) ultimate limit states (see 3.1.3); b) serviceability limit states (see 3.1.4). Typical ultimate limit states are depicted in figure 3. Rupture states which are reached before collapse occurs are, for simplicity, also classified and
中英文对照外文翻译 (文档含英文原文和中文翻译) Create and comprehensive technology in the structure global design of the building The 21st century will be the era that many kinds of disciplines technology coexists , it will form the enormous motive force of promoting the development of building , the building is more and more important too in global design, the architect must seize the opportunity , give full play to the architect's leading role, preside over every building engineering design well. Building there is the global design concept not new of architectural design,characteristic of it for in an all-round way each element not correlated with building- there aren't external environment condition, building , technical equipment,etc. work in coordination with, and create the premium building with the comprehensive new technology to combine together. The premium building is created, must consider sustainable development , namely future requirement , in other words, how save natural resources as much as possible, how about protect the environment that the mankind depends on for existence, how construct through high-quality between architectural design and building, in order to reduce building equipment use quantity and
包装设计外文翻译文献(文档含中英文对照即英文原文和中文翻译)
包装对食品发展的影响 消费者对某个产品的第一印象来说包装是至关重要的，包括沟通的可取性，可接受性，健康饮食形象等。食品能够提供广泛的产品和包装组合，传达自己加工的形象感知给消费者，例如新鲜包装/准备，冷藏，冷冻，超高温无菌，消毒（灭菌），烘干产品。 食物的最重要的质量属性之一，是它的味道，其影响人类的感官知觉，即味觉和嗅觉。味道可以很大程度作退化的处理和/或扩展存储。其他质量属性，也可能受到影响，包括颜色，质地和营养成分。食品质量不仅取决于原材料，添加剂，加工和包装的方法，而且其预期的货架寿命（保质期）过程中遇到的运输和储存条件的质量。越来越多的竞争当中，食品生产商，零售商和供应商；和质量审核供应商有着显著的提高食品质量以及急剧增加包装食品的选择。这些改进也得益于严格的冷藏链中的温度控制和越来越挑剔的消费者。 保质期的一个定义是：在规定的贮存温度条件下产品保持其质量和安全性的时间。在保质期内，产品的生产企业对该产品质量符合有关标准或明示担保的质量条件负责，销售者可以放心销售这些产品，消费者可以安全使用。 保质期不是识别食物等产品是否变质的唯一标准，可能由于存放方式，环境等变化物质的过早变质。所以食物等尽量在保质期未到期就及时食用。包装产品的质量和保质期的主题是在第3章中详细讨论。
包装为消费者提供有关产品的重要信息，在许多情况下，使用的包装和/或产品，包括事实信息如重量，体积，配料，制造商的细节，营养价值，烹饪和开放的指示，除了法律准则的最小尺寸的文字和数字，有定义的各类产品。消费者寻求更详细的产品信息，同时，许多标签已经成为多语种。标签的可读性会是视觉发现的一个问题，这很可能成为一个对越来越多的老年人口越来越重要的问题。 食物的选择和包装创新的一个主要驱动力是为了方便消费者的需求。这里有许多方便的现代包装所提供的属性，这些措施包括易于接入和开放，处置和处理，产品的知名度，再密封性能，微波加热性，延长保质期等。在英国和其他发达经济体显示出生率下降和快速增长的一个相对富裕的老人人口趋势，伴随着更加苛刻的年轻消费者，他们将要求和期望改进包装的功能，如方便包开启（百货配送研究所，IGD）。 对零售商而言存在有一个高的成本，供应和服务的货架体系。没有储备足够的产品品种或及时补充库存，特别是副食品，如鲜牛奶，可能导致客户不满和流失到竞争对手的商店，这正需要保证产品供应。现代化的配送和包装系统，允许消费者在购买食品时，他们希望在他们想任何时间地点都能享用。近几年消费者的选择已在急剧扩大。例如在英国，20世纪60年代和90年代之间在一般超市的产品线的数量从2000年左右上升到超过18000人（INCPEN）。 自20世纪70年代以来，食品卫生和安全问题已成为日益重要的关注和选择食物的驱动力。媒体所关注的一系列问题，如使用化学添
本科生毕业设计（论文）外文科技文献译文 译文题目(外文题目)学院(系)Socket网络编程的设计与实现A Design and Implementation of Active Network Socket Programming 机械与能源工程学院 专学业 号 机械设计制造及其自动化 071895 学生姓名李杰林 日期2012年5月27日指导教师签名日期
摘要：编程节点和活跃网络的概念将可编程性引入到通信网络中，并且代码和数据可以在发送过程中进行修改。最近，多个研究小组已经设计和实现了自己的设计平台。每个设计都有其自己的优点和缺点，但是在不同平台之间都存在着互操作性问题。因此，我们引入一个类似网络socket编程的概念。我们建立一组针对应用程序进行编程的简单接口，这组被称为活跃网络Socket编程（ANSP）的接口，将在所有执行环境下工作。因此，ANSP 提供一个类似于“一次性编写，无限制运行”的开放编程模型，它可以工作在所有的可执行环境下。它解决了活跃网络中的异构性，当应用程序需要访问异构网络内的所有地区，在临界点部署特殊服务或监视整个网络的性能时显得相当重要。我们的方案是在现有的环境中，所有应用程序可以很容易地安装上一个薄薄的透明层而不是引入一个新的平台。 关键词：活跃网络；应用程序编程接口；活跃网络socket编程
1 导言 1990年，为了在互联网上引入新的网络协议，克拉克和藤农豪斯[1]提出了一种新的设 计框架。自公布这一标志性文件，活跃网络设计框架[2，3，10]已经慢慢在20世纪90 年代末成形。活跃网络允许程序代码和数据可以同时在互联网上提供积极的网络范式，此外，他们可以在传送到目的地的过程中得到执行和修改。ABone作为一个全球性的骨干网络，开 始进行活跃网络实验。除执行平台的不成熟，商业上活跃网络在互联网上的部署也成为主要障碍。例如，一个供应商可能不乐意让网络路由器运行一些可能影响其预期路由性能的未知程序，。因此，作为替代提出了允许活跃网络在互联网上运作的概念，如欧洲研究课题组提出的应用层活跃网络（ALAN）项目[4]。 在ALAN项目中，活跃服务器系统位于网络的不同地址，并且这些应用程序都可以运行在活跃系统的网络应用层上。另一个潜在的方法是网络服务提供商提供更优质的活跃网络服务类。这个服务类应该提供最优质的服务质量（QOS），并允许路由器对计算机的访问。通过这种方法，网络服务提供商可以创建一个新的收入来源。 对活跃网络的研究已取得稳步进展。由于活跃网络在互联网上推出了可编程性，相应 地应建立供应用程序工作的可执行平台。这些操作系统平台执行环境（EES），其中一些已 被创建，例如，活跃信号协议（ASP）[12]和活跃网络传输系统（ANTS）[11]。因此，不 同的应用程序可以实现对活跃网络概念的测试。 在这些EES 环境下，已经开展了一系列验证活跃网络概念的实验，例如，移动网络[5]，网页代理[6]，多播路由器[7]。活跃网络引进了很多在网络上兼有灵活性和可扩展性的方案。几个研究小组已经提出了各种可通过路由器进行网络计算的可执行环境。他们的成果和现有基础设施的潜在好处正在被评估[8，9]。不幸的是，他们很少关心互操作性问题，活跃网络由多个执行环境组成，例如，在ABone 中存在三个EES，专为一个EES编写的应用程序不能在其他平台上运行。这就出现了一种资源划分为不同运行环境的问题。此外，总是有一些关键的网络应用需要跨环境运行，如信息收集和关键点部署监测网络的服务。 在本文中，被称为活跃网络Socket编程（ANSP）的框架模型，可以在所有EES下运行。它提供了以下主要目标： ??通过单一编程接口编写应用程序。 由于ANSP提供的编程接口，使得EES的设计与ANSP 独立。这使得未来执行环境的发展和提高更加透明。
中英文对照外文翻译文献(文档含英文原文和中文翻译)
原文： Norway Romsdal Folk Museum Photograph from : Stiftelsen Romsdalsmuseet The Romsdal Folk Museum is an architectonic attraction and a treasured landmark that embodies the history and identity of the entire region. Our intention in this project was to let the structure signal its meaning and function through an architectural expression and the use of local materials. The scale of the building refers to the urbanity and morphology of the town. The overall layout of the museum grounds the connections to the town by linking different surrounding areas in an overall plan where all circulation is linked in a unified structure. The project conveys an open and progressive attitude that makes diverse utilization possible. The Museum design approach is rooted in rationality and sustainability. The plan geometry is deceptively simple, the characteristic angled shapes are limited to the roof and the external wall, making the circulation and internal organisation clear and flexible. The public areas are clearly separated from the administration wing, which is located on both the ground and first floor. Exhibition rooms, the auditorium and the library are all placed on the ground floor to increase flexibility and user experience. The transparency of the reception room permits supporting internal and external activities. Large sliding doors separate the permanent and temporary exhibition areas, giving the curators the ability to combine or separate the spaces. The archives and workshops are located on the basement level, with the vertical circulation of large items facilitated by a large goods lift.Pine is the primary building material of the museum. Exterior walls and roof are made of solid timber in combination of steel beam when required. The terrain entailed the use of concrete, however its use was reduce to the foundations. Exterior walls and ceilings covered with maintenance-pine relief tempered with bio-based oil.Different openings filter the daylight in such way that the internal space are enriched by gradations and translucency nuances. However, the main exhibition rooms are black boxes, giving the curators total control of artificial lightening in these areas. All the glazing units have high-energy performance glass, in some locations with silk printed colours and patterns. The impact on the Nordic society:The Romsdal Folk Museum is a great example of strategic use of low-tech building solutions. It embodies the national policy in Norway to aim for a more sustainable future. The museum is built using Norwegian timber technology and acts as a hub for
编号： 毕业设计(论文)外文翻译 （原文） 院（系）：应用科技学院 专业：机械设计制造及其自动化 学生姓名：邓瑜 学号：0501120501 指导教师单位：应用科技学院 姓名：黄小能 职称： 2009年 5 月20 日
The Injection Molding The Introduction of Molds The mold is at the core of a plastic manufacturing process because its cavity gives a part its shape. This makes the mold at least as critical-and many cases more so-for the quality of the end product as, for example, the plasticiting unit or other components of the processing equipment. Mold Material Depending on the processing parameters for the various processing methods as well as the length of the production run, the number of finished products to be produced, molds for plastics processing must satisfy a great variety of requirements. It is therefore not surprising that molds can be made from a very broad spectrum of materials, including-from a technical standpoint-such exotic materials as paper matched and plaster. However, because most processes require high pressures, often combined with high temperatures, metals still represent by far the most important material group, with steel being the predominant metal. It is interesting in this regard that, in many cases, the selection of the mold material is not only a question of material properties and an optimum price-to-performance ratio but also that the methods used to produce the mold, and thus the entire design, can be influenced. A typical example can be seen in the choice between cast metal molds, with their very different cooling systems, compared to machined molds. In addition, the production technique can also have an effect; for instance, it is often reported that, for the sake of simplicity, a prototype mold is frequently machined from solid stock with the aid of the latest technology such as computer-aided (CAD) and computer-integrated manufacturing (CIM). In contrast to the previously used methods based on the use of patterns, the use of CAD and CAM often represents the more economical solution today, not only because this production capability is available pin-house but also because with any other technique an order would have to be placed with an outside supplier. Overall, although high-grade materials are often used, as a rule standard materials are used in mold making. New, state-of-the art (high-performance) materials, such as ceramics, for instance, are almost completely absent. This may be related to the fact that their desirable characteristics, such as constant properties up to very high temperatures, are not required on molds, whereas their negative characteristics, e. g. low tensile strength and poor thermal conductivity, have a clearly related to ceramics, such as sintered material, is found in mild making only to a limited degree. This refers less to the modern materials and components