The paper presents a large scale nonlinear model which is used for supporting international negotiations aimed at improving air quality in Europe. The model helps to identify cost effective measures for reducing air p...
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The paper presents a large scale nonlinear model which is used for supporting international negotiations aimed at improving air quality in Europe. The model helps to identify cost effective measures for reducing air pollution emissions and to examine the resulting concentrations of tropospheric ozone acidification and eutrophication. Several methodological and technical issues related to the specification, generation and optimization-based analysis of large nonlinear models for decision support that are of a more general interest are presented.
Gismo is a highly interactive program, with an iconic human interface and a 3D graphics display, which was developed in order to investigate the feasibility of using object-oriented programming within high-energy phys...
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Gismo is a highly interactive program, with an iconic human interface and a 3D graphics display, which was developed in order to investigate the feasibility of using object-oriented programming within high-energy physics. It allows the user to design a detector and save it to disk, to track Monte Carlo events through such a detector, to simulate the detector response, and to reconstruct an event from this response. Gismo was developed using objective-C and the Interface Builder on a NeXT computer, and the speed with which it was possible to build an application of this complexity indicates that the techniques used warrant further investigation.
Teaching algorithmization and programming has been recently going through big changes trying to react to the dynamic development of software industry. Previously used methodical process, development models, or program...
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Teaching algorithmization and programming has been recently going through big changes trying to react to the dynamic development of software industry. Previously used methodical process, development models, or programming languages do not conform to current requirements. The results of the surveys in primary and secondary schools, we can say that the teaching of programming and algorithms are not sufficiently exploited. The aim of this paper is to present practical experience of the author teaching programming and the possibilities of using design patterns in the teaching of programming. According to the performed analyzes the procedures and methodologies of teaching programming shows that Design Patterns are used only marginally. For these reasons, students learn to improper practices that subsequently applied in practical solutions programs. According to the experiments show that the correct use of the teaching of design patterns can improve student performance in programming
Real-time systems engineers have, for some time, identified Java as an attractive programming language, but have been unable to exploit its benefits as it cannot provide the fundamental temporal predictability require...
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Real-time systems engineers have, for some time, identified Java as an attractive programming language, but have been unable to exploit its benefits as it cannot provide the fundamental temporal predictability required. However, this is all changing, as academic and industrial experts propose extensions to the Java environment. On the basis of this study, significant agreement has been found in how some of the critical areas of Java may be addressed for real-time, such as memory management and portability. However, areas such as scheduling and interprocess communication, have been contentious, even among expert opinion. This paper considers the current status of this exciting and emerging, soon to become, real-time programming language, with a focus on process control application. In addition, it will overview a preliminary performance assessment of the alleged real-time java virtual machine (JVM) from NewMonics Inc and compared upfront with the Sun JVM.
The paper refers to the description of an object-oriented approach to the formalisation of parallel DEDS modelling tools. The goal of the presented approach is to develop a modelling framework that enables the modular...
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The paper refers to the description of an object-oriented approach to the formalisation of parallel DEDS modelling tools. The goal of the presented approach is to develop a modelling framework that enables the modular and hierarchical construction of complex DEDS with the structured view of the underlying state space. The basic notions are defined, e.g., the state classes, the dynamic model of the objects and the operation of the parallel composition. The parallel composition of the objects’ models express the dynamic relations between objects of different classes in dependence on theirs states and occurred events. The method of the analysis of the model concerning to the reachability of the given configuration is also discussed. This point will be the further step of the research activity. At the end, a simple example and its program realisation in the C++ language is given.
In recent times, the subject of interoperability has become very popular. In large-scale software applications development, it is a common practice to combine multiple languages in solving peculiar problems and develo...
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In recent times, the subject of interoperability has become very popular. In large-scale software applications development, it is a common practice to combine multiple languages in solving peculiar problems and developing robust solutions. The ability to combine multiple languages allows an easy migration of an existing project from one language to another or use existing libraries in another language. This makes interoperability a force to be reckoned with when developing new programming languages. The Eolang programming language is a new research and development initiative aimed at achieving true object-oriented programming by having all components of the program as objects. As such, the construct and syntax of Eolang is vastly different from that of Java. This makes integration and interoperability between these two languages a challenging issue related to method/object naming conventions, keywords and operators, etc. In this paper we explore the potential of Eolang interoperability with Java by looking at the interoperability mechanisms of some other languages with Java, describe ways to overcome these challenges with Eolang and develop the solution. Specifically, we focus on the possibility to call Java code from Eolang while the semantics of both languages remain preserved. Our solution allows Java code to be called in Eolang through wrappers that turn Java classes and methods into Eolang objects.
We present a constraint system, OF, of feature trees that is appropriate to specify and implement type inference for first-class messages. OF extends traditional systems of feature constraints by a selection constrain...
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We present a constraint system, OF, of feature trees that is appropriate to specify and implement type inference for first-class messages. OF extends traditional systems of feature constraints by a selection constraint x z, "by first-class feature tree" y, which is in contrast to the standard selection constraint x[f]y, "by fixed feature" f. We investigate the satisfiability problem of OF and show that it can be solved in polynomial time, and even in quadratic time if the number of features is bounded. We compare OF with Treinen's system EF of feature constraints with first-class features, which has an NP-complete satisfiability problem. This comparison yields that the satisfiability problem for OF with negation is NP-hard. Further we obtain NP-completeness, for a specific subclass of OF with negation that is useful for a related type inference problem. Based on OF we give a simple account of type inference for first-class messages in the spirit of Nishimura's recent proposal, and we show that it has polynomial time complexity: We also highlight an immediate extension of this type system that appears to be desirable but makes type inference NP-complete.
The didactic system developed at São Paulo University, the MFG Toolkit, consists of a simulator for control objects and a controller. In both systems it is utilized the same modeling tool, the MFG/PFS (Mark Flow ...
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The didactic system developed at São Paulo University, the MFG Toolkit, consists of a simulator for control objects and a controller. In both systems it is utilized the same modeling tool, the MFG/PFS (Mark Flow Graph/Production Flow Schema), derived from Petri Nets. This modeling tool is the keystone of the MFG/PFS Methodology. The case study shown here illustrates the operation sequence for the MFG Toolkit which involves the usage of MFG/PFS Methodology for contriving a model for a given control object and a control algorithm for it.
Multiphysics applications are real world problems with a large number of different shape components that obey different physical laws and manufacturing constraints and interact with each other through geometric and ph...
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Multiphysics applications are real world problems with a large number of different shape components that obey different physical laws and manufacturing constraints and interact with each other through geometric and physical interfaces. They demand accurate and efficient solutions and a modern type of computational modeling, which designs the whole physical system with as much detail as possible. The simulation of gas turbine engine is such a multiphysics application and is realized with GasTurbnLab, an agent-based Multiphysics Problem Solving Environment (MPSE). Its performance and evaluation study is presented in this paper. For this, a short description of the software components and hardware infrastructure is given. The performance and the scalability of the parallelism are depicted, and the communication overhead between agents is studied with respect to the number of agents and their location in the "computational grid." The execution time is recorded, and its analysis verifies the complexity of the solvers in use and the performance of the available hardware. Three different clusters of INTEL Pentium processors were used for experimentation to study how the communication time was affected by processor's homogeneity/heterogeneity and the different connections between the processors. The study of the numerical experiments shows that the domain decomposition and interface relaxation methodology, along with the usage of agent platforms, does not increase the complexity of the simulation problem, and the communication cost is too low, compared with the computations, to reflect on the total simulation time. Therefore, GasTurbnLab is an efficient example of a complex physical phenomena simulation.
Fitness-for-service assessment of a cracked component intends to evaluate its remaining strength and remaining life to support the implementation of a maintenance plan. This research aims to develop a fitness-for-serv...
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Fitness-for-service assessment of a cracked component intends to evaluate its remaining strength and remaining life to support the implementation of a maintenance plan. This research aims to develop a fitness-for-service assessment software to facilitate the task. The software development process included identifying the software specifications, designing the software structure, manipulating the information in the standard for programming, the graphical user interface design, and finally verification. The assessment procedure employed in this study was the third edition of the standard API RP 579. The software structure was designed using an object-oriented concept. The software can perform integrity assessment levels 1, 2, and 3 option B, leak-before-break assessment, and remaining life assessment for a cracked cylinder that has a through-thickness crack or semi-elliptical surface crack oriented in an axial or circumferential direction. The applied loads could be a nominal axial force, bending moment, and internal pressure, as well as stress profiles perpendicular to the crack plane due to mechanical, thermal, and residual stresses. Accuracy of the software was demonstrated by applying it to example problems. Some aspects of the software extensibility were conceptually discussed.
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