GPSS has been used for years to teach simulation. Different tools following the GPSS syntax exist. Usually these tools can be used to construct simulation models helping in the teaching of simulation. However no avail...
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ISBN:
(纸本)9781424457700;9781424457717
GPSS has been used for years to teach simulation. Different tools following the GPSS syntax exist. Usually these tools can be used to construct simulation models helping in the teaching of simulation. However no available framework is capable to simplify the development of a complete simulation tool following the GPSS syntax. This paper presents JGPSS, a framework based in javalanguage that can be used by students to build a complete simulation tool following the GPSS syntax. JGPSS has two versions, one capable to perform simulations and obtain statistical information, and other designed as a framework for students of computer sciences. This last framework, described in this paper, lacks in the implementation of the main simulation engine algorithms or the related structures. This framework allows the computer science student to reach a deeper understanding of how to construct a complete process interaction simulation engine, the paradigm that GPSS follows.
Problem-tracing questions are popular among teachers of various programminglanguages. In an assessment mode these questions allows to evaluate student knowledge of language semantics. In a self-assessment mode, they ...
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ISBN:
(纸本)9781605583815
Problem-tracing questions are popular among teachers of various programminglanguages. In an assessment mode these questions allows to evaluate student knowledge of language semantics. In a self-assessment mode, they provide an excellent learning tool. A 2004 ITiCSE working group report [4] stressed the importance of this type of questions to build foundation of higher-level knowledge. Yet the use of problem-tracing questions is still limited due to a large authoring overhead. To resolve this bottleneck, we explored the idea of parameterized question generation [2]. We developed QuizPACK [1], a system which can generate parameterized problem-tracing questions for C programminglanguage. We also developed QuizGuide [1], a personalized guidance system for QuizPACK, which models student knowledge and guides students individually to most appropriate questions to try. The results of our studies demonstrated that QuizPACK strongly benefits student knowledge and that QuizGuide personalized guidance technology increased student ability to answer questions correctly and encouraged them to use the system more extensively (which, in turn, positively impacted their knowledge) [1]. However, parameterized questions in area of C programming were not as diverse from the complexity point of view as parameterized questions explored in other areas such as physics [2]. As a result, it was left unclear whether personalized guidance technology can successfully guide students to a broader range of questions from relatively simple to very difficult.
We implemented a translator from a subset of C to java that guarantees safety. For such translation, we need to emulate C's pointer arithmetics in java. We thus defined java classes to represent C's pointers a...
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We implemented a translator from a subset of C to java that guarantees safety. For such translation, we need to emulate C's pointer arithmetics in java. We thus defined java classes to represent C's pointers and memory blocks. Next, we defined translation rules which use these classes, and implemented a translator following the rules. We also need to translate integers as pointers, because they can be cast to each other in C. However, representing all integers as pointers incurs too much overhead. We therefore implemented optimizations, including a data flow analysis for translating C's integer variables (to which no pointers are assigned) to java's integer variables. We conducted experiments with 9 benchmark programs. Without optimizations, the translated programs were 3.3-585 times slower than the original C programs. After the optimizations, those numbers improved to 1.3-5.9.
The state of a concurrent object, intended as some abstraction over the values of the fields of the object, usually determines its coordination behavior. Therefore, state is always in the programmer's mind, even t...
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The state of a concurrent object, intended as some abstraction over the values of the fields of the object, usually determines its coordination behavior. Therefore, state is always in the programmer's mind, even though implicitly. We suggest a feature for J ava-like languages, which makes the state of a concurrent object explicit and supports the expression of the object's behavior depending on the state it is currently in. Namely, an object will be in one of the states declared in its class. The state determines the presence of fields and methods. State transition statements explicitly change the state of an object, and thus change the availability of fields and methods. When a thread calls a method which is declared in the object's class but absent from its current state, it waits, until the state of the object changes to a state which does contain that method. This directly expresses coordination. We claim that this feature makes it easier to understand and develop concurrent programs, and substantiate our claim through the discussion of some popular examples of concurrent programs written using this *** develop a type and effect system, which guarantees that, during execution of a method invoked on a concurrent object. No attempt will be made to access fields not available in the current state of and (2) No method invoked on a receiver (syntactically) different from may cause the invocation of a method on the latter guarantee helps to enforce the former and prevents a family of accidental violations of the intended coordination protocol.
This paper develops an SECS Communication Module, which conforms to SEMI standard, using the Object-oriented Analysis/Design (OOA/D) method. The two main features of SECS Communication Module are Unified Modeling Lang...
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The jLab environment extends the potential of java for scientific computing. It provides a Matlab/Scilab like scripting language that is executed by an interpreter implemented in the javalanguage. The jLab environmen...
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The jLab environment extends the potential of java for scientific computing. It provides a Matlab/Scilab like scripting language that is executed by an interpreter implemented in the javalanguage. The jLab environment combines effectively Groovy like compiled scripting with the interpreted jScript one. A special purpose modification of the Groow language, called GroovySci is developed for effective compiled scripting. The paper concentrates on the topic of using the jLab scripting engine from within a pure java application, in order to allow the application to utilize the scientific scripting potential of jLab and its large scientific libraries. The implementation is inspired by the JSR 223 standard but it is much simpler. The same methodology for script invocation can also be used within the Groovy effective compiled scripting framework. We describe the basics of the Groovy scripting environment. To our knowledge, this is the first full Matlab like scientific scripting for java.
This article constitutes a thorough presentation of an original scheme for portable CPU accounting and control in java, which is based on program transformation techniques at the bytecode level and can be used with ev...
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In this paper we introduce a novel web server architecture that combines the best aspects of both the multithreaded and the event-driven architectures, the two major existing alternatives, to create a server model tha...
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CPL (Call Process language) is a scripting language for the description and control of communication service, and it expresses its content by using functional component in XAE language. This paper presents a component...
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ISBN:
(纸本)9780769532905
CPL (Call Process language) is a scripting language for the description and control of communication service, and it expresses its content by using functional component in XAE language. This paper presents a component reuse mechanism, and defines a matrix technique to inspect the conflict of component composition. By comparing the difference of CPL and java grammar, this paper brings forward a translation mechanism, via which we can translate CPL to equal functional java code in the framework of XML language. This mechanism adopts the idea of EJB container, and constructs the whole services after the form of class object, and describes the CPL componenst as javaBeans. By this way, the java code translated has character of easily readable, highly reusable and extendable. This mechanism is applied in our service creation system, and achieves good results.
A wide range of techniques for supporting software maintenance tasks rely on representations of program control flow. The accuracy of these representations can be important to the effectiveness and efficiency of these...
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ISBN:
(纸本)9781424426133
A wide range of techniques for supporting software maintenance tasks rely on representations of program control flow. The accuracy of these representations can be important to the effectiveness and efficiency of these techniques. The java programming language has introduced structured exception handling features that complicate the task of representing control flow. Previous work has attempted to address these complications by using type inference algorithms to analyze the control flow effects of exceptions, but to date, there has been no study of whether the use of these algorithms is justified In this paper we report results of an empirical study addressing this issue. We find that type inference algorithms can lead to more accurate representations of control flow, but this improvement does not necessarily translate into benefits for maintenance techniques that use them. It follows that type inference algorithms should not just automatically be applied;rather the tradeoffs of applying them must first be assessed with respect to particular maintenance techniques and workloads.
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