In the area of parallel processing, performance has been the primary goal, and historically, parallel software writers paid less attention to software portability. However, as software is becoming more complicated, co...
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ISBN:
(纸本)1581132883
In the area of parallel processing, performance has been the primary goal, and historically, parallel software writers paid less attention to software portability. However, as software is becoming more complicated, costs for developing and maintaining parallel applications are rapidly increasing. Reusable and portable software is certainly needed even in the parallel processing area. java appeared on the scene under the slogan of "Write once, run anywhere", advertising portability as its largest advantage. java Grande Forum was established to achieve two goals;portability and highperformance. Current Forum discussions seem to concentrate on optimization of java programs, elements of numerical libraries, message passing interface for java, etc. Few implementations of practical applications are presented so far. To find out obstacles in writing Grand Challenge applications in java, empirical studies on developing large and practical applications in java are strongly desired. As an example of practical distributed parallel applications, we have implemented two versions of a parallel multi-pass rendering system. One version is written in C++ and the other is written in java. The multi-pass rendering method is a combination of radiosity and ray-tracing methods. These implementations, about 56,000 lines in total, are publicly available at http://***/research/cg/.These two programs are based-on the identical algorithm and are directly comparable in terms of performance and efficiency in software development. Experimental results on Sun Enterprise with JDK 1.2.1 and gcc 2.7.2 which is used only for compiling message passing library show that compared to the C++ version, the performance of the java version is about three to five times slower and requires approximately four to seven times more memory space. We also discuss some problems encountered in developing practical parallel distributed applications in java.
java applications represent a broad class of programs, ranging from programs running on embedded products to high-performance server applications. Standard java benchmarks ignore this fact and assume a fixed workload....
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ISBN:
(纸本)1581132883
java applications represent a broad class of programs, ranging from programs running on embedded products to high-performance server applications. Standard java benchmarks ignore this fact and assume a fixed workload. When an actual application's behavior differs from that included in a standard benchmark, the benchmark results are useless, if not misleading. In this paper, we present HBench:java, an application-specific benchmarking framework, based on the concept that a system's performance must be measured in the context of the application of interest. HBench:java employs a methodology that uses vectors to characterize the application and the underlying JVM and carefully combines the two vectors to form a single metric that reflects a specific application's performance on a particular JVM such that the performance of multiple JVMs can be realistically compared. Our performance results demonstrate HBench:java's superiority over traditional benchmarking approaches in predicting real application performance and its ability to pinpoint performance problems.
Beginning in the spring 1999 semester and continuing, the authors have used a simple javascript routine to create web-based practice tests for students in various classes. Feedback from students has been very positive...
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Beginning in the spring 1999 semester and continuing, the authors have used a simple javascript routine to create web-based practice tests for students in various classes. Feedback from students has been very positive. Students indicate that the question-feedback cycle helps them gauge their readiness and feel more confident for the real exam. This paper will discuss how the program works, how educators can enter customized test questions for the program using a simple text editor, and provide a web link for educators to use to download the program and customize it for their own classes.
Instruction-level parallelism of stack codes like java is severely limited by accessing the operand stack sequentially. To resolve this problem in java processor design, our earlier works have presented stack operatio...
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This paper describes the design of a high-performance linear algebra library for java. Linear algebra libraries such as ESSL and LAPACK are important tools of computational science and engineering, and have been avail...
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ISBN:
(纸本)1581132883
This paper describes the design of a high-performance linear algebra library for java. Linear algebra libraries such as ESSL and LAPACK are important tools of computational science and engineering, and have been available to C and Fortran programmers for quite a while. If java is to become a serious language for the development of large scale numerical applications, it must provide equivalent functionality. From the many possible alternatives to accomplish this goal, we took the approach of designing a linear algebra library entirely in java. This approach leads to good portability and maintainability of the code. It is also a good test of how far we can push java performance. We adopted an object-oriented design in which the linear algebra operations are implemented as strategy design patterns. The higher level algorithms, optimized for the memory hierarchies of present-day machines, are described in a type independent manner. Type specific methods capture the lower level optimizations for operations on matrices of single-precision, double-precision, or complex numbers. We evaluate the performance of our linear algebra package on three different machines. Our preliminary results show that our java library achieves up to 85% of the performance of the highly optimized ESSL.
Satin is a system for running divide and conquer programs on distributed memory systems (and ultimately on wide-area metacomputing systems). Satin extends java with three simple Cilk-like primitives for divide and con...
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The undeniable popularity of the web makes the efficient accessing of distributed databases from web clients an important topic. Various methods for web database integration have been proposed but recently there is an...
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The undeniable popularity of the web makes the efficient accessing of distributed databases from web clients an important topic. Various methods for web database integration have been proposed but recently there is an increasing interest on those based on java-based ones. This is due to the inherent advantages of java, which supports platform independence and secure program execution, and produces a small size of compiled code. In this experimental paper, we evaluate all currently available java-based approaches. These include java applets, java Sockets, Servlets, Remote Method Invocation, CORBA, and Mobile Agents. To this end, we implemented a Web client accessing a remote database using each of these approaches and compared their behavior along the following important parameters: (1) performance expressed in terms of response time under different loads, (2) transparency of communication expressed in terms of complexity of networking API, and (3) extensibility expressed in terms of ease of adding new components.
This paper describes a framework that supports a collaborative work environment for scientific computing. Implemented using the java programming language, the framework allows teams of researchers to collectively visu...
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Mainstream object-oriented languages, such as C++ and java, provide only a restricted form of polymorphic methods, namely single-receiver dispatch. In common programming situations, programmers must work-around this l...
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A series of Web-based instructional units for the first undergraduate course in structural engineering are developed. The instructional units are centered on computer programs written in the object-oriented java progr...
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A series of Web-based instructional units for the first undergraduate course in structural engineering are developed. The instructional units are centered on computer programs written in the object-oriented java programming language. Each instructional unit consists of a series of HTML documents containing java applets. The HTML pages have a standard format and contain the following elements: statement of educational goals, background and theory, description of applet, series of examples and exercises, suggestions for further study and exploration, supplemental information to assist other instructors, and an online evaluation form for suggestions and comments. The instructional units and the embedded applets are available over the Internet to students and instructors throughout the nation. Examples of the applets developed include: determinacy and indeterminacy of trusses and frames;shear, moment and deflection analysis of beams;analysis of determinate and indeterminate trusses;analysis of determinate and indeterminate frames;and influence lines for continuous beams. The advantages of using java and the World Wide Web for teaching are discussed and examples of the use of these applets in the classroom are presented.
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