Educational Innovations in Multimedia Systems1
Wayne Burleson, Aura Ganz, Ian Harris
Department of Electrical and Computer Engineering
University of Massachusetts Amherst, MA 01003
{burleson, ganz, harris}@https://www.doczj.com/doc/d1318684.html,
Abstract: Multimedia systems have emerged as one of the fastest growing segments of computing systems and thus need to be well integrated into a computer engineering curriculum. Fortunately the teaching and learning of multimedia systems can be aided with novel instructional techniques based on multimedia. The Multimedia Curriculum project at the University of Massachusetts Amherst is developing a unified set of instructional materials on the engineering techniques used in the design and test of hardware, software and networks for multimedia. This large project includes three facets: 1) multimedia instructional modules using web-linked Digital Video Disks, 2) multimedia communication utilities to facilitate student interaction and 3) multimedia component design projects. In this paper, we explain our approach to using multimedia as both content and instructional technology and briefly present preliminary results in each of the three facets.
1.0 Why Multimedia Systems?
We define a multimedia system to be a computer-based communications system which delivers heterogeneous and compressed/coded/encrypted content (text, audio, video, graphics) from a source or storage device and transfers it over a heterogeneous channel (Internet, wireless network, local area network) to an end-user while maintaining perceptual integrity (Figure 1).
New multimedia systems have emerged in many forms in the last 5 years and are now a major driver in the design of computer hardware, networks, and both system and application software. Processors, RAM, cache, disk, display, sound card, graphics card, network card, operating system, browser and editors have all been modified to target multimedia systems. Multimedia presents a new class of applications in computing which is quite different than the business and scientific applications that drove previous generations of computing systems. It spans real-time computing, signal processing, and communications issues and thus requires a very wide range of technical background. Multimedia systems engineering is an opportunity to substantially update and invigorate undergraduate computer engineering curricula while providing exciting new content for exploring new instructional methods and technology.
1 An early version of this paper won the Ben Dasher Best Paper Award at the 1999 Frontiers in Education Conference [ FIE99]
Figure 1: Multimedia Systems: The User's View
Multimedia systems also provide a motivating theme for integrating many of the fields of computer engineering thus encouraging multidisciplinary work.
?First, multimedia systems require a systems approach to design that covers the generation, transmission, storage and retrieval of widely varying content. Algorithm, hardware and software design problems can be unified in an integrated context, thus providing students with a ``big-picture" view of computer engineering {DeMan}. We use this systems approach in design projects at all levels, requiring students to work in teams and deal with many design issues and constraints simultaneously.
?Secondly, multimedia systems designs involve a significant amount of statistical and probabilistic analysis for the estimation of performance and signal quality, thus substantially motivating math and signal processing courses in the curriculum. Simulation and visualization tools are used to show how system and algorithmic choices impact the resulting media product and result in variable run-times.
?Third, multimedia systems provide very tangible functionality (and misfunctionality!) to students, hopefully motivating them and showing real applications without compromising engineering fundamentals.
2.0 The UMASS Multimedia Curriculum project:
“Using Multimedia to Learn Multimedia”
The UMASS Multimedia Curriculum project is led by 7 faculty in the Computer Systems Engineering area within the Department of Electrical and Computer Engineering. Together, we are developing a set of integrated instructional tools and curricular innovations which are unified by the common theme of multimedia systems. Our approaches to this problem consist of:
?multimedia instructional modules using web-linked Digital Video Disks described in Section 3,
?multimedia communication utilities to facilitate student interaction described in Section 4, and
?multimedia component design projects described in Section 5.
Extensive multimedia archives, source code, demonstrations, modules, authoring materials and project details can be found at the Multimedia Curriculum project web-site:
https://www.doczj.com/doc/d1318684.html,/ece/dvd
3.0 Multimedia Instructional Modules
We are developing interactive multimedia instructional modules in the following 6 areas related to multimedia systems.
?MODULE 1: Natural Content Coding (video, audio)
?MODULE 2: Synthetic Content Coding (graphics)
?MODULE 3: Multimedia Networks
?MODULE 4: Multimedia Architectures and Operating Systems
?MODULE 5: Design/CAD for Multimedia Hardware
?MODULE 6: Testing of Multimedia Systems
Together, the modules provide an integrated problem domain which cuts a wide swath through the field of computer engineering. With 7 different faculty developing 6 different modules in this project, we are able to amortize the module development infrastructure over a wide range of content and teaching styles. We believe that the overhead required to develop any re-usable instructional modules is significant enough that the infrastructure should be used by a variety of faculty in a variety of courses. We have developed a generic module template with utilities for novel functions (interactive video lectures, interactive video demonstrations, links to related design projects) , but we see significant variation in the individual modules due to the different topic areas and teaching styles.
These modules directly impact 6 undergraduate ECE courses as well as being used as short course tutorials for distance learning and self-paced instruction. The modules are based on a combination of interactive Digital Video Disks and Web technology, allowing a combination of high quality video and audio along with hot-links to the Web. The next three sections show three different approaches to multimedia modules production. The first, WebDVD, provides multiple camera angles and instructional materials but in an unsynchronized format. The philosophy here is to allow asynchronous use of the materials with synchronization left up to the viewer. This is similar to reading a textbook or set of notes that go along with a lecture . The second format, MANIC, provides streamed audio over the Internet with synchronized HTML slides. MANIC uses RealPlayer and various features of the Netscape and Internet Explorer web browsers to maintain synchronization and allow indexing. The third format is a low-cost CD/DVD format that requires only very basic PC equipment and a digital video camera and microphone. It is intended for faculty that do not have access to a professional video studio or video-serving capability.
3.1 WebDVD: Multiple Camera Angles with Unsynchronized Instructional Materials
Figure 2a Clip from WebDVD course on VLSI testing for video coding modules (Prof. I. Harris)
3.2 MANIC: Streaming Audio with Synchronized HTML
Figure 2 shows a screen shot from a module on VLSI design which illustrates many of the concepts in our multimedia modules. The video is captured in the professional studios of our Video Instructional Program just like any regular UMASS academic course or short course. We then digitize the video and integrate it with other course materials onto the DVD. Initially we use the MANIC system, developed in the UMASS Computer Science department {MANIC}, to integrate slides and video stills with synchronized audio into an Internet-based format that can be viewed by a standard
browser (e.g. Explorer or Netscape) and media player (e.g. RealPlayer). The authoring process is quite efficient compared to tools like Macromedia Director, taking only about 2-3 hours for every hour of live lecture. This ratio depends on the amount of animation and annotation that is desired. UMASS undergrad Brendan English converted 31 hours of video lectures containing 528 slides to the MANIC format during a winter vacation week.
The MANIC system allows easy navigation through the modules, either asynchronously by choosing the slides from a table of contents or search engine, or synchronously by just playing the audio and allowing the slides to be advanced automatically. At any point, the student can stop the presentation and interact. Current forms of interaction include:
1)navigation through slides via a hierarchical PDF-style table-of-contents,
2)following links to other slides, glossaries and external web-sites,
3)searching for key words that appear in the slides titles and text (search for keywords in video, audio or image is not
currently supported).
Details on MANIC can be found at: https://www.doczj.com/doc/d1318684.html,/
Figure 2b: Clip from VLSI course using MANIC format (Prof. W. Burleson)
3.3 Low-Cost Video Production Environment
For faculty that do not have access to a professional video studio, we have also experimented with a low cost multimedia production method that incorporates web based material, slides, video and audio. The required hardware and software can be purchased for less than $5000.
Hardware:1. Pentium PC 500MHz, 256 MB RAM, 2. Hauppauge WinTV (Video capture card that transfers in real time the video signal from a digital video camera to the computer screen). 3. Hitachi digital video camera, 4. Microphone Software:1. Microsoft Media Player,2. HyperCam ( Video screen capture software), 3. Adobe Premier (Video editing) The digital video camera captures the instructor that faces the PC screen that displays: 1) the web browser that views the slides prepared in html format and 2) the video of the instructor that is captured by the video capture card. The HyperCam software captures in real time all the contents of this screen including the mouse movements and highlighting and records it in .avi format (10 MB per minute of video clip). The .avi file is cut and trimmed in Adobe Premier and and then compressed to an MPEG format. Although this format is intended for DVD/CD rather than Internet streaming, clips can be viewed at: https://www.doczj.com/doc/d1318684.html,/miu/. A sample of the format can be seen in Figure 2c. This work was developed with Annan Phonphoem and Kitti Wongthavarawat
Figure 2c Low-cost video instructional format used on Networking module (Prof. A. Ganz)
3.4 Encouraging Student Interaction with Modules using Applets, Quizzes and Demonstrations
Students can also interact with the lectures by requesting examples and demonstrations, which are written either as Java Applets run on the client or CGI programs run on the server. We have developed a number of Java applets that provide students with an interactive multimedia experience that enables them to grasp a number of networking concepts.
1.Routing concepts. The user can input any network layout (any number of nodes, links and link weights). Students can
program their own routing algorithm and compare it to the classical shortest path.
https://www.doczj.com/doc/d1318684.html,/kenny/j_spf.htm. The complex dynamics of ad-hoc networking are shown in Figure 3a.
2.ATM routing algorithms. The user can input the network layout (nodes, links, links' weight, capacity and length), the
routing algorithm (min-hop and min-delay) and the percentage of video traffic in the network. Figure 3b displays the delay versus virtual circuit (VC) arrival rate and also the percentage of accepted VCs versus the VC arrival rate.
https://www.doczj.com/doc/d1318684.html,/qyu/ece696/index.html
3.Weighted Fair Queue Service Discipline: The applet shows how the weighted fair queuing discipline works in a
network switch under different prioritized multimedia traffic loads. Figure 4 shows this applet. The applet can be viewed and downloaded at https://www.doczj.com/doc/d1318684.html,/miu/JavaApplets/WeightedFairQueue/Wfq.htm
Additional applets can be viewed at https://www.doczj.com/doc/d1318684.html,/miu/.
Figure 3a: Applet for observing ATM performance on video traffic
Figure 3b Applet demonstrating ad-hoc networking both visually and statistically. User enters parameters.
Figure 4 Java applet demonstrating Weighted Fair Queueing of multimedia traffic both visually and statistically. User enters rate and priority parameters.
An example of an interactive demonstration of the MPEG encoding algorithm is shown in Figure 5. In the first screen shot, the student chooses a number of parameters for the encoding algorithm and then submits them to the MPEG coder. In the second screen shot, the results of the student’s parameters choices are shown, including the statistics of the MPEG-1 encoding program (run-time, compression ratio, file sizes, etc.) as well as the actual test video (in this case, the benchmark
Table Tennis video which shows varying object motion (ball and paddle) and zooming). This work was done with UMASS PhD student Jeongseon Euh and uses the public domain MPEG coder developed at UC Berkeley.
Figure 5: Interactive MPEG demo
Another form of student interaction is an on-line homework system. At any point during a module or outside of the module, students can choose a set of questions specified by topic and difficulty level. For example, after viewing 15 minutes of a lecture on Video coding algorithms, the student might request 3 intermediate-level questions on motion estimation techniques or, 2 questions drawn from the last n minutes of the presentation or m slides of the presentation. Another scenario is that a well-prepared student who already has some background in a particular area might request some questions before viewing the lecture. This allows students to make the best use of their time by “testing-out” of sections that they may already know. The homework can also be used to preview lectures and review material for exams, projects, job interviews, etc. Homework problems can also link to the interactive demos and applets thus providing continuity between the lectures and the homework. The software provides immediate feedback after the students submit answers. The feedback includes the score for each session, accumulated score for all sessions, how long students take to finish each session, right or wrong for each question (if an answer is wrong the program will present a correct answer to students). Details and a demo of the homework system can be found at https://www.doczj.com/doc/d1318684.html,/quiz/index.html. The homework system was developed with Jianxin Wang, Xin Liu and Noel Llopis. In the questions/answers database we are developing the ability to display multimedia files such as figures, video and audio. Figure x shows an example where students choose one of several hyperlinks to MPEG video files as a response to a multiple choice question.
Our homework system is different than the many other on-line homework systems (see recent FIE proceedings) in the following ways:
?emphasis on multimedia in question and answers
?integration with modules (questions tagged by topic, time and difficulty)
?mixed-mode to support automated grading as well as human grading
?integrated with applets and demos
3.5 Handwritten Presentation Styles
In order for any teaching technology to be quickly adopted in a widespread manner, it is essential that additional effort on the part of the teacher should be minimized. Even the most well-intentioned teacher is unlikely to have sufficient free time in his/her schedule to learn a complicated new presentation format. For this reason, our work strives to allow the teacher to present educational material in an intuitive fashion allowing informal handwritten “back-of-the-napkin” formats. The challenge is to balance the intuitiveness of the presentation style with the ease of digitizing the educational material for distribution to students.
Figure 6: Annotation of an electronic document using a digitizing pad and Microsoft Paint
One method which we have investigated to provide a natural presentation interface is the use of a drawing tablet, together with a simple drawing tool such as Microsoft Paint which is shipped with Windows98. The Cross IpenPro which we are using, allows the mouse to be controlled by moving a pen across a pad. A mouse click is performed by applying downward pressure to the pen. By using the drawing pad with a drawing program, the teacher can draw directly onto the computer screen, and annotate an existing drawing, as shown in Figure 6. We have found this interface to be a nice addition to electronic presentation materials (i.e. Powerpoint) because it allows a very natural interface for the teacher, while also instantly digitizing the data for distribution either on CD/DVD or on the Internet.
Another approach we use to allow annotation of electronic materials is a video overlay technique. This requires video mixing capability which we have in our video studios. Unlike the IpenPro, this results in a video rather than a still image overlay, allowing full animation to capture the comments and annotation style of the instructor. Figure 7 below shows the video overlay technique in a VLSI chip design course where the instructor is tracing a schematic over a representation of the manufacturing masks.
Figure 7 Video Overlay of Powerpoint slides originally from Digital Integrated Circuits by J. Rabaey, Prentice-Hall 4.0 Multimedia Communication Utilities
We have developed a variety of multimedia utilities to support communication and collaboration in conjuction with the instructional modules of Section 3 and the design projects of Section 5. Despite the promise of technology for the formal delivery of educational materials, we feel that some of the strongest benefits of technology are just to enable informal human-to-human interaction. Ideally each student could freely and frequently interact with the professor, the teaching assistant and their fellow students. However, the reality of time limitations and scheduling conflicts makes this difficult. One of the simplest, most general and most effective solutions has been the use of electronic mail and bulletin boards. We have developed several utilities that make it easier to discuss, critique, annotate, and revise multimedia objects. These are used in standard academic courses but are most important in design project courses.
One of the most fundamental utilities allows the student to submit an arbitrary multimedia file into the on-line homework system. Thus, a student can provide an audio file or a graphics file as a solution to a homework or quiz problem. This significantly expands the homework system beyond the limitations of automated multiple-choice question styles and also supports students with various communication and learning disabilities.
A multimedia bulletin board allows students to post their work and then view and comment on it. This is similar to students preparing their own Web pages except that commenting and interaction between students is better supported. Contributions can be listed either threaded by subject, or ordered by time of posting. Multimedia files such as figures, video and voice can be posted.
We have developed a multimedia whiteboard that allows students and the professor to actually collaborate on the design of a multimedia document. A document can be viewed with annotations in color and text added by the professor and students (Figure 8). A distributed client-server framework allows multiple documents from different courses and projects to be open at the same time, encouraging multidisciplinary collaboration. In addition to the whiteboard, we have also developed a multimedia chat program and a multimedia forum which are based on the same principles but have different modes of interaction. For example, chat and forum store a transcript of the interaction while whiteboard just stores the most current document. Chat is synchronous while the whiteboard and the forum are optionally asynchronous. In conclusion, all of these Internet-based communication systems can benefit from specific multimedia support. This work was done by UMASS undergraduate students Jeff Peden and Chris Leonardo and was presented to a multimedia research community at [ICME 2000] and an educational community at [EWME 2000].
Figure 8: Multimedia Whiteboard showing on-line commenting by multiple designers of a VLSI layout for Huffman coding
5.0 Multimedia Component Design Projects
Multimedia modules provide a good introduction to a topic area, but a more effective and realistic technique for learning computer engineering involves a team-based hands-on design project. To support this, we have developed an archive of hardware and software design projects related to multimedia systems and linked to the instructional modules at various levels. To facilitate these projects, we rely on the modules described in Section 3 as well as the utilities in Section 4. We have incorporated multimedia themes into several of our undergraduate design project courses. Projects vary from software and networking to architecture, microprocessor and VLSI design depending on the course. In the VLSI design course, we have projects in Audio Coding, Discrete Cosine and Wavelet Transforms, Image Filtering, LZ coding, Arithmetic coding, Huffman Coding, Cryptography and Video Motion Estimation. Although these are components or sub-systems, rather than complete multimedia systems, they all present significant challenges for the senior-level students since they have to thoroughly understand the correct functionality of the blocks before they can design the circuits and generate proper test vectors for simulations.
We have found that the modules are very useful as a review for students doing multimedia design projects. Students in a VLSI project course are designing a Huffman coding unit that uses a barrel shifter and a RAM. By searching for these keywords in the VLSI module, they can get a quick overview of the design issues for these blocks. Even for students that have never studied a particular topic, the modules can be used to give a quick introduction. For example, we have students designing a Lempel-Ziv compression chip who have never encountered the basic Lempel-Ziv algorithm. Rather than give them a journal article or textbook as background, or ask them to just “find it on the Web", or require a semester length Data compression course, the module allows a quick introduction to the topic from an instructor whose presentation style and reputation they already know.
Expertise in the testing of multimedia systems is becoming required for system designers in industry and should therefore be introduced at the undergraduate level. Multimedia systems can be used to teach many concepts of testing in a very tangible way. Testing, in turn, forces students to carefully look at their design from an external viewpoint, addressing issues such as I/O, standards, and manufacturing defects. Several aspects of multimedia systems make their testing a
unique problem:
?Real-Time Systems: Multimedia systems are typified by a high bandwidth user interface which must meet real-time constraints. The high bandwidth required in many applications, such as video, can push design performance limits and necessitate delay optimization and delay verification {Sifakis92}.
?Heterogeneous Systems: A typical multimedia application is built from many heterogeneous components which are required to interface the digital representation of multimedia data with the physical senses of the user, typically through audio and video. System components vary widely in terms of data throughput and implementation technology.
Hierarchical design is well-known but a hierarchical testing {HierMurr90} approach is required to accomodate the various testing approaches required for each component.
?Mixed-Signal Systems: The large majority of multimedia systems are based on digital components. However, because human senses are inherently analog, multimedia systems must include analog components as well. Mixed-signal design and testing present challenges beyond either digital or analog {MilorMixed98}.
?Standards Implementation: Intense consumer demand for multimedia systems has driven standardization efforts in order to increase volume and reduce costs. The purpose of standardization is to create a common high-level functionality across different products, while giving a large degree of freedom in system implementation. Because different implementations of a standard will vary greatly, standards compliance tests {MpegComp95} must be designed which are independent of internal design.
Each design project is associated with a set of objectives which the students must achieve. The goals fall into three categories which collectively span the entire flow of a project from concept to product.
?Design - Students must design a circuit, or some subcomponents of a circuit, from a high-level specification. The abstraction level of the design created varies by project. For example, a project for a sophomore class in logic design may involve board-level design using gate-level components, while a senior VLSI design project will involve layout-level design.
?Verification -Students must verify the correctness of their design. This involves the definition of a simulation model or
a design. The simulation model will either be in an HDL language (VHDL, Verilog) or in a software language (C,
Java), as appropriate to the design level. Verification will also require that the students design a set of functional vectors which stimulate potential design errors. The process of creating a set of test vectors forces the student to have a thorough understanding of the internals of the design.
?Manufacturing Test - Students must verify that the physical circuit performs the task specified by the design. Notice that this step is different from verification because manufacturing test identifies physical faults in the manufacturing process, as opposed to design errors. The nature of the manufacturing faults is dependent on the level of the manufacturing process. Our projects involve three different manufacturing processes: board-level, FPGA, and LSI fabrication. Requiring students to test for manufacturing faults provides them with an understanding of the manufacturing process, as well as the design process.
We now present three undergraduate design projects that involve typical multimedia testing and verification issues. The scope of these projects has been limited to fit a typical junior or senior level lab course. By fully understanding the design and test of one of these designs, students get a glimpse of the design and test of multimedia systems in general.
Project 1:Bouncing Lights Design The circuit designed in this project use light emitting diodes (LEDs) to represent a bouncing ball whose movement is controlled by a set of switches and a potentiometer. The output interface of the final circuit is a row of LEDs, all of which are lit except one. The unlit LED acts as the ``ball'' which ``bounces'' between the left end and the right end of the row of LEDs. The inputs to the circuit are a reset switch which starts the bouncing, a hold switch which holds the position of the ball, and speed potentiometer to control the speed of bouncing.
This is intended to be an early, sophomore level, student design experience, involving breadboarding using primarily TTL logic components. The circuit is a finite state machine with a variable speed clock to control the bouncing speed. The circuit
design is subdivided into two components, (1) finite state machine logic to sequence the lights, and (2) clock generation logic to generate the variable speed clock. The finite state machine logic is based on an up/down counter used to select the unlit LED. The clock control logic uses an analog-to-digital converter to translate the potentiometer resistance into the downsampling rate for the clock.
This project fulfills our educational objectrives because it exposes students to many fundamental aspects of multimedia design early in their undergraduate education. This design includes a simple video interface in the form of LEDs, and enables students to explore issues relating to subjective qualities of the output. For example, a common problem is that an LED may appear dim because it is alternating between on/off states more quickly than is perceptible. The student goals of this project are twofold, (1) design and build the circuit, and (2) test the circuit for manufacturing defects. Since this project involves manual wiring, many defects related to wiring are to be expected. For the purpose of simplicity, we require the detection of only {\em open} defects which occur when a wire between two points has not been connected. As an additional challenge, the students are asked to diagnose the faults as well as possible without probing internal signals, using only the input and output interface. Requiring students to diagnose without probing gives the students an appreciation of the difficulty of test observability, particularly in VLSI chip design where internal probing is often impossible.
Project 2: VLSI Design of Modular Exponentiation for Cryptography The Montgomery modular multiplication algorithm is a central component of many cryptography systems. Since cryptography is important for a large class of Internet-based secure multimedia applications, this design is a component in many multimedia systems. Since encryption/decryption are performed on the incoming/outgoing media data streams, modular exponentiation is part of the critical performance path and requires delay verification. Modular exponentiation is also part of the RSA encryption standard. Although the implementation of the exponentiator is not defined in the RSA standard, the behavior of the exponentiator must be correct in order to guarantee the compliance of the larger RSA system.
As an implementation model, we use the linear array design presented in [Paar]. This project is intended for a senior
level lab course, and assumes a basic understanding of VHDL. The student objectives of this project are (1) design the component in VHDL, (2) generate several test streams for validation, and (3) insert test hardware into the design and explore the area/testability tradeoff. We have made a VHDL simulation model if a length 4 linear array version of this design, as well as an associated test bench, which should be used as a reference model. The complexity of the project can be scaled by the instructor by varying the length of the linear array of processing elements, or by targeting an FPGA implementation rather than an ASIC implementation. Evaluation of the area/testability tradeoff is performed by modifying the design by inserting test registers. The test registers improve testability while sacrificing area. The testability of the modified designs is evaluated using tools which we have developed here, as well as freeware for test generation and fault simulation [PROOFS].
Project 3: Video Motion Estimation Array Motion estimation is critical part of the popular MPEG video compression standard, used in a wide range of multimedia equipment. Motion estimation is the most compute-intensive step of the MPEG encoding task. The high performance standards of digital video applications make delay verification essential in motion estimation. The verification of this design necessitates adherence to the requirements of the MPEG standard, and gives students exposure to compliance testing.
As an implementation model, we use the 16 element linear array design presented in [Konstantinides] which estimates the motion of a 16x16 pixel reference block within a 32x32 pixel search window. Each processing element of the array shown in Figure 9 compares the reference block to a unique 16 pixel wide column of the search window. The student objectives of this project are (1) design the component in VHDL, (2) generate several test streams for validation, and (3) insert test hardware into the design and explore the area/testability tradeoff. The complexity of the project can be scaled by altering the search window size to reduce the number of processing elements, or by altering the number of bits used to represent each pixel. We have developed a VHDL model for the design which can be used for verification. The verification problem here is interesting because the results of a design error can be observed visually by using the component to encode a video sequence. Students can perform rudimentary diagnosis relating visual effects on the encoded image to design and manufacturing defects.
Figure 9 Motion Estimation Array for Video Coding (Project 3)
6.0 Evaluation
This project is ongoing and presents numerous innovations that must be evaluated to determine their value in improved teaching and learning. We have just begun this large effort by piloting the various modules, utilities and projects into our own curriculum. After these pilot runs, we will also actively disseminate the materials to five other diverse institutions around the world (ENST Paris, Pusan Nat. Univ., Korea, National Technological Univ., Smith College, and the Springfield Technical Community College). Our evaluation strategy consists of four components:
1) Student evaluation of the teaching materials. Throughout the design of the modules, the utilities and the design projects we have incorporated numerous ideas from students. Undergraduates are heavily involved in the project. Early survey of the Networking module indicated 98% student satisfaction. A recent graduate course in Wireless Communications indicated that the pace of our modules was too slow and that the video lectures were too low quality to provide an stimulating learning environment. We are addressing this concern by using better video coders and trying to more carefully target the modules to different student audiences.
2) Assessment of student learning using pre- and post-tests for students using the modules versus a control group. Our homework system administration tools provide the course instructor the ability to edit and modify quiz files, and analyze quiz results. A more informal approach will be used for student projects due to the difficulty in formally assessing learning in design.
3) Feedback from the 5 dissemination institutions on the benefits of the modules, utilities and projects to students and faculty. The authoring tools and source code are made available to these institutions as well as a module explaining how to develop your own modules.
4) Feedback from industrial partners who hire our students and use our courses for continuing education (e.g. Compaq, Sun, Samsung, Intel, Cadence, Cisco, Motorola.)
References:
[DeMan] H. DeMan, Keynote address in ACM/IEEE Design Automation Conference, 1997.
[FIE99] W. Burleson, A. Ganz, I. Harris, "Educational Innovations in Multimedia Systems", Frontiers in Education Conference '99
[ICME00] W. Burleson, J. Peden, C. Leonardo, "Distributed VLSI Design Education using The Multimedia Online Collaboration Architecture (MOCA)", Proc. of European Workshop on Microelectronics Design, (EWME), Kluwer, May 2000
[EWME00] J. Peden, W. Burleson, C. Leonardo, "The Multimedia Online Collaboration Architecture: Tools to Enable Distance Learning", Proc of IEEE International Conference on Multimedia, August, 2000
[MANIC] M. Stern, J. Steinberg, H.I. Lee, J. Padhye, J. Kurose, "MANIC: Multimedia Asynchronous Networked Individualized Courseware," Proc. of Educational Multimedia and Hypermedia, 1997.
[MpegComp95], P. Meehan and N. Hurst and M. Isnardi and P. Shah, MPEG Compliance Bitstream Design, International Conference on Consumer Electronics, June, 1995, pp.174-175.
[MilorMixed98],L. S. Milor, A Tutorial Introduction to Research on Analog and Mixed-Signal Circuit Testing, IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, vol. 45, no. 10, 1998.
[Sifakis92] J. Sifakis, Real-Time Systems Specification and Verification, International Symposium on System Synthesis, September,1995.
[HierMurr90], B. T. Murray and J. P. Hayes, Hierarchical Test Generation Using Precomputed Tests for Modules, IEEE Transactions on Computer Aided Design, vol. 9, no.6, June, 1990, pp.=594-603.
[Paar] T.Blum and C. Paar., Montgomery modular exponentiation on reconfigurable hardware. Proc. of IEEE Symposium on Computer Arithmetic, April 1999.
[PROOFS] T. M. Niermann, W.-T.Cheng, and J.~H. Patel. Proofs: A fast, memory-efficient sequential circuit fault simulator. IEEE Transactions on Computer-Aided Design, 11(2):198--207, February 1992.
[Konstantinides] V. Baskaran and K. Konstantinides, Image and Video Cokmpression Standards, Kluwer Academic Publishers, 1997.
Acknowledgements:
The UMASS Multimedia Curriculum project is funded by the National Science Foundation grant EIA-9812589 and the University of Massachusetts. We acknowledge the work, support and ideas of all members of the project, including Professors M.Ciesielski, I.Koren, C.M.Krishna and F.S. Hill; UMASS students: J. Peden, B. English, J. Euh, A. Nalamalpu, C. Duggirala, J.Wang, X. Liu, N. Llopis, K. Zheng, A. Phonphoem and K. Wongthavarawat.We also thank the Video Instructional Program, the Engineering Computer Services and the UMASS Computer Science Department MANIC project for providing technical services and use of equipment.
of与for的用法以及区别 for 表原因、目的 of 表从属关系 介词of的用法 （1）所有关系 this is a picture of a classroom （2）部分关系 a piece of paper a cup of tea a glass of water a bottle of milk what kind of football，American of soccer？ （3）描写关系 a man of thirty 三十岁的人 a man of shanghai 上海人 （4）承受动作 the exploitation of man by man．人对人的剥削。 （5）同位关系 It was a cold spring morning in the city of London in England． （6）关于，对于 What do you think of Chinese food？ 你觉得中国食品怎么样？ 介词 for 的用法小结 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。What will we have for supper? 我们晚餐吃什么?
2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。
to与for的用法和区别 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb.表示对某人有直接影响比如，食物对某人好或者不好就用to; for表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语？ 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．对于 1．She has a liking for painting. 她爱好绘画。 2．She had a natural gift for teaching. 她对教学有天赋/ 3．表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法？ 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于（常有较活译法） 1 Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，对于（某人），对…来说（多和形容词连用）用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。 6．for和fit, good, bad, useful, suitable 等形容词连用，表示适宜，适合。 Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 Exercises are good for health. 锻炼有益于健康。 Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 You are not suited for the kind of work you are doing. 7. for表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 1．It would be best for you to write to him. 2．The simple thing is for him to resign at once. 3．There was nowhere else for me to go. 4．He opened a door and stood aside for her to pass.
For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。 尽管for 的用法较多，但记住常用的几个就可以了。 to的用法: 一：表示相对，针对 be strange (common, new, familiar, peculiar) to This injection will make you immune to infection. 二：表示对比，比较 1：以-ior结尾的形容词，后接介词to表示比较，如：superior ,inferior,prior,senior,junior 2: 一些本身就含有比较或比拟意思的形容词，如equal，similar，equivalent，analogous A is similar to B in many ways.
介词for用法归纳 用法1：(表目的)为了。如： They went out for a walk. 他们出去散步了。 What did you do that for? 你干吗这样做？ That’s what we’re here for. 这正是我们来的目的。 What’s she gone for this time? 她这次去干什么去了？ He was waiting for the bus. 他在等公共汽车。 【用法说明】在通常情况下，英语不用for doing sth 来表示目的。如： 他去那儿看他叔叔。 误：He went there for seeing his uncle. 正：He went there to see his uncle. 但是，若一个动名词已名词化，则可与for 连用表目的。如： He went there for swimming. 他去那儿游泳。(swimming 已名词化) 注意：若不是表目的，而是表原因、用途等，则其后可接动名词。(见下面的有关用法) 用法2：(表利益)为，为了。如： What can I do for you? 你想要我什么？ We study hard for our motherland. 我们为祖国努力学习。 Would you please carry this for me? 请你替我提这个东西好吗？ Do more exercise for the good of your health. 为了健康你要多运动。 【用法说明】(1) 有些后接双宾语的动词(如buy, choose, cook, fetch, find, get, order, prepare, sing, spare 等)，当双宾语易位时，通常用for 来引出间接宾语，表示间接宾语为受益者。如： She made her daughter a dress. / She made a dress for her daughter. 她为她女儿做了件连衣裙。 He cooked us some potatoes. / He cooked some potatoes for us. 他为我们煮了些土豆。 注意，类似下面这样的句子必须用for： He bought a new chair for the office. 他为办公室买了张新办公椅。 (2) 注意不要按汉语字面意思，在一些及物动词后误加介词for： 他们决定在电视上为他们的新产品打广告。 误：They decided to advertise for their new product on TV. 正：They decided to advertise their new product on TV. 注：advertise 可用作及物或不及物动词，但含义不同：advertise sth＝为卖出某物而打广告；advertise for sth＝为寻找某物而打广告。如：advertise for a job=登广告求职。由于受汉语“为”的影响，而此处误加了介词for。类似地，汉语中的“为人民服务”，说成英语是serve the people，而不是serve for the people，“为某人的死报仇”，说成英语是avenge sb’s death，而不是avenge for sb’s death，等等。用法3：(表用途)用于，用来。如： Knives are used for cutting things. 小刀是用来切东西的。 This knife is for cutting bread. 这把小刀是用于切面包的。 It’s a machine for slicing bread. 这是切面包的机器。 The doctor gave her some medicine for her cold. 医生给了她一些感冒药。 用法4：为得到，为拿到，为取得。如： He went home for his book. 他回家拿书。 He went to his friend for advice. 他去向朋友请教。 She often asked her parents for money. 她经常向父母要钱。
of 1....的,属于 One of the legs of the table is broken. 桌子的一条腿坏了。 Mr.Brown is a friend of mine. 布朗先生是我的朋友。 2.用...做成的;由...制成 The house is of stone. 这房子是石建的。 3.含有...的;装有...的 4....之中的;...的成员 Of all the students in this class,Tom is the best. 在这个班级中,汤姆是最优秀的。 5.(表示同位) He came to New York at the age of ten. 他在十岁时来到纽约。 6.(表示宾格关系) He gave a lecture on the use of solar energy. 他就太阳能的利用作了一场讲演。 7.(表示主格关系) We waited for the arrival of the next bus. 我们等待下一班汽车的到来。
I have the complete works of Shakespeare. 我有莎士比亚全集。 8.来自...的;出自 He was a graduate of the University of Hawaii. 他是夏威夷大学的毕业生。 9.因为 Her son died of hepatitis. 她儿子因患肝炎而死。 10.在...方面 My aunt is hard of hearing. 我姑妈耳朵有点聋。 11.【美】(时间)在...之前 12.(表示具有某种性质) It is a matter of importance. 这是一件重要的事。 For 1.为,为了 They fought for national independence. 他们为民族独立而战。 This letter is for you. 这是你的信。
1.两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for：(1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如：do sb a favour＝do a favour for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害
for的用法： 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如:
I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如:
1.表示各种“目的”，用for （1）What do you study English for 你为什么要学英语？ （2）went to france for holiday. 她到法国度假去了。 （3）These books are written for pupils. 这些书是为学生些的。 （4）hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．“对于”用for （1）She has a liking for painting. 她爱好绘画。 （2）She had a natural gift for teaching. 她对教学有天赋/ 3．表示“赞成、同情”，用for （1）Are you for the idea or against it 你是支持还是反对这个想法？ （2）He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 （3）I felt deeply sorry for my friend who was very ill. 4. 表示“因为，由于”（常有较活译法），用for （1）Thank you for coming. 谢谢你来。
（2）France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，“对于（某人），对…来说”，（多和形容词连用），用介词to，不用for. （1）He said that money was not important to him. 他说钱对他并不重要。 （2）To her it was rather unusual. 对她来说这是相当不寻常的。 （3）They are cruel to animals. 他们对动物很残忍。 6．和fit, good, bad, useful, suitable 等形容词连用，表示“适宜，适合”，用for。（1）Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 （2）Exercises are good for health. 锻炼有益于健康。 （3）Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 （4）You are not suited for the kind of work you are doing. 7. 表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 （1）It would be best for you to write to him. （2） The simple thing is for him to resign at once.
常用介词用法(for-to-with-of)
For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。
5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。
加入收藏夹 主题： 介词试题It’s + 形容词 + of sb. to do sth.和It’s + 形容词 + for sb. to do sth.的用法区别。 内容： It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 提交人：杨天若时间：1/23/2008 20:5:54 主题：for 与of 的辨别 内容：It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 答：选A 解析：该题考查的句型It’s + 形容词+ of sb. to do sth.和It’s +形容词+ for sb. to do sth.的用法区别。 “It’s + 形容词+ to do sth.”中常用of或for引出不定式的行为者，究竟用of sb.还是用for sb.，取决于前面的形容词。 1) 若形容词是描述不定式行为者的性格、品质的，如kind，good，nice，right，wrong，clever，careless，polite，foolish等，用of sb. 例： It’s very kind of you to help me. 你能帮我，真好。 It’s clever of you to work out the maths problem. 你真聪明，解出了这道数学题。 2) 若形容词仅仅是描述事物，不是对不定式行为者的品格进行评价，用for sb.，这类形容词有difficult，easy，hard，important，dangerous，（im）possible等。例： It’s very dangerous for children to cross the busy street. 对孩子们来说，穿过繁忙的街道很危险。 It’s difficult for u s to finish the work. 对我们来说，完成这项工作很困难。 for 与of 的辨别方法： 用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for. 如： You are nice.(通顺，所以应用of)。 He is hard.(人是困难的，不通，因此应用for.) 由此可知，该题的正确答案应该为A项。 提交人：f7_liyf 时间：1/24/2008 11:18:42
1. 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for： (1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如： do sb a favou r do a favour for sb 帮某人的忙 do sb harnn= do harm to sb 对某人有害
to和for的用法有什么不同（一） 一、引出间接宾语时的区别 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for，具体应注意以下三种情况： 1. 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. 2. 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose, prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes?
正：Can you spare a few minutes for me? 3. 有的动词由于用法和含义不同，用介词to 或for 都是可能的。如： do sb a favor＝do a favor for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害 在有的情况下，可能既不用for 也不用to，而用其他的介词。如： play sb a trick＝play a trick on sb 作弄某人 请比较： play sb some folk songs＝play some folk songs for sb 给某人演奏民歌 有时同一个动词，由于用法不同，所搭配的介词也可能不同，如leave sbsth 这一结构，若表示一般意义的为某人留下某物，则用介词for 引出间接宾语，即说leave sth for sb；若表示某人死后遗留下某物，则用介词to 引出间接宾语，即说leave sth to sb。如： Would you like to leave him a message? / Would you like to leave a message for him? 你要不要给他留个话？ Her father left her a large fortune. / Her father left a large fortune to her. 她父亲死后给她留下了一大笔财产。 二、表示目标或方向的区别 两者均可表示目标、目的地、方向等，此时也要根据不同动词分别对待。如： 1. 在come, go, walk, move, fly, ride, drive, march, return 等动词之后通常用介词to 表示目标或目的地。如： He has gone to Shanghai. 他到上海去了。 They walked to a river. 他们走到一条河边。
keep的用法 1. 用作及物动词 ①意为"保存；保留；保持；保守"。如： Could you keep these letters for me, please? 你能替我保存这些信吗？ ②意为"遵守；维护"。如： Everyone must keep the rules. 人人必须遵守规章制度。 The teacher is keeping order in class.老师正在课堂上维持秩序。 ③意为"使……保持某种(状态、位置或动作等)"。这时要在keep的宾语后接补足语，构 成复合宾语。其中宾语补足语通常由形容词、副词、介词短语、现在分词和过去分词等充当。如： 例：We should keep our classroom clean and tidy.(形容词) 我们应保持教室整洁干净。 You'd better keep the child away from the fire.(副词)你最好让孩子离火远一点。 The bad weather keeps us inside the house.(介词短语)坏天气使我们不能出门。 Don't keep me waiting for long.(现在分词)别让我等太久。 The other students in the class keep their eyes closed.(过去分词) 班上其他同学都闭着眼睛。 2. 用作连系动词 构成系表结构：keep＋表语，意为"保持，继续(处于某种状态)"。其中表语可用形容词、副词、介词短语等充当。如： 例：You must look after yourself and keep healthy.(形容词) 你必须照顾好自己，保持身体健康。 Keep off the grass.(副词)请勿践踏草地。 Traffic in Britain keeps to the left.(介词短语)英国的交通是靠左边行驶的。 注意：一般情况下，keep后接形容词较为多见。再如： She knew she must keep calm.她知道她必须保持镇静。 Please keep silent in class.课堂上请保持安静。 3. ①keep doing sth. 意为"继续干某事"，表示不间断地持续干某事，keep后不 能接不定式或表示静止状态的v-ing形式，而必须接延续性的动词。 例：He kept working all day, because he wanted to finish the work on time. 他整天都在不停地工作，因为他想准时完成工作。 Keep passing the ball to each other, and you'll be OK.坚持互相传球，你们就
202X中考英语：to和for的区别与用法中考栏目我为考生们整理了“202X中考英语：to和for的区别与用法”，希望能帮到大家，想了解更多考试资讯，本网站的及时更新哦。 202X中考英语：to和for的区别与用法 to和for的区别与用法是什么 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb. 表示对某人有直接影响比如，食物对某人好或者不好就用to; for 表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语? 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。
2.对于 1.She has a liking for painting. 她爱好绘画。 2.She had a natural gift for teaching. 她对教学有天赋。 3.表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法? 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于(常有较活译法) 1.Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5.当事人对某事的主观看法，对于(某人)，对?来说(多和形容词连用)用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。
to , of 和for的区别 1.to有到的意思，常常和go，come，get连用引出地点。Go to school , go to the shop , go to the cinema. 常见的短语：the way to 去---的路 On one’s way to 在某人去---的路上 以上的用法中，当地点是副词home，here，there等是to 要去掉。如：get home，the way here To后跟动词原形，是不定式的标志 It is +形容词+(for/of +人+)to do sth.(括号内部分可以省略) It is easy for me to learn English. It is very kind of you to lend me your money. 当形容词表示人的行为特征时用of表示to do的性质时用for Want, hope ,decide, plan , try , fail等词后跟to do I want to join the swimming club. Would like to do I’d like to play basketball with them. It is time to have a break. Next to , close to , from ---to--- 2.for 为，表示目的。 Thank you for Buy sth for sb =buy sb sth It is time for bed. Here is a letter for you.
I will study for our country. 3.of表示所属关系意思是：---的 a map of the world a friend of mine
for和of引导的不定式结构的区别 不定式是一种非谓语动词，不能单独作谓语，因此没有语法上的主语。但由于不定式表示的是动作，在意义上可以有它的主体。我们称之为逻辑主语。 提起不定式逻辑主语，人们首先想到的会是“for+名词（宾格代词）+不定式”的复合结构。如：It is important for us to study English well．然而，有时不定式的逻辑主语须要用“of+名词（代词宾格）”才行。例如：It is kind of you to help me．而不能说：It is kind for you to help me．在选择介词“for”还是“of”时，人们往往总是凭感觉而定。有时受习惯影响，多选介词“for”。于是常出现这样的错误：It was careless for him to lose his way．It is cruel for you to do so．由于众多语法书对这种结构中使用“for”与“of”的区别介绍甚少，一些人对其概念认识尚不完全清楚，笔者认为有必要就这一问题作些探讨与介绍。 一、在句中的语法作用不同 a．不定式for结构在句中可以作主、宾、表、定、状、同位语： 1．It is easy for Tom to do this work．（主语）汤姆做此工作是容易的。 2．I'd like for him to come here．（宾语）我喜欢他来这里。 3．His idea is for us to travel in two different groups．（表语）他的想法是：我们分成两组旅行。 4．Have you heard about the plan for you to go abroad．（定语）你听到让你出国的计划吗？ 5．The word is too difficult for him to pronounce well．（状语）这单词太难，他念不准。 6．In the most schools，it is the custom for the headmaster to declare the newterm start．在大部分学校，校长宣布新学期开始是一个习惯。 b．不定式of结构只能在句中作主语。 1．It was careless of him to leave his umbrella in the train．他把伞丢在火车上真是太粗心了。 2．It is awfully good of you to come to see me off at the station．谢谢你来车站送我。 二、逻辑主语的名词有所不同