The general objective of this paper is to describe the way the authors have been relating general system theory (GST) to practice. The authors applied GST to design a methodology for software development, first. Then,...
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The general objective of this paper is to describe the way the authors have been relating general system theory (GST) to practice. The authors applied GST to design a methodology for software development, first. Then, by means of the experience/knowledge learned from applying the methodology to specific systems, a continuous redesigning process started, which simultaneously generalized the methodologies and increased its complexity adding new modules for an increasing diversity of diverse-tasks needed for different systems/situations. The methodological kernel increased it generality and the sub-methodological modules increased its details. This paved the way for a general systems methodology which, when including cognitive/thinking method would return to the theoretical realm, i.e. to a methodological theory which, in turn, would pave the way to theoretical methodology.
Pattern detection is part of many solutions to software engineering problems. Unfortunately, it is a hard problem in itself in both theory and practice. Both exact and approximative approaches have been used earlier t...
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Pattern detection is part of many solutions to software engineering problems. Unfortunately, it is a hard problem in itself in both theory and practice. Both exact and approximative approaches have been used earlier to increase efficiency. We propose a novel method to improve the performance of pattern detection, which is in many cases both exact and efficient. It is based on the idea of filtering information from the program representation (graphs), which is unnecessary for detecting a particular pattern. This makes the remaining program representation graph planar, in many cases, thus allowing for linear pattern detection. We evaluate our approach experimentally: we detect six design patterns in six software systems. Filtering leads to planar program representation graphs in 14 out of 36 cases. For most of the remaining graphs, filtering makes the graphs almost planar and gives a significant reduction of the graph size, which speeds up existing heuristics.
The connection between polymorphic and dynamic typing was originally considered by Curry et al. (1972, Combinatory logic, vol. ii) in the form of "polymorphic type assignment" for untyped lambda-terms. Types...
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The connection between polymorphic and dynamic typing was originally considered by Curry et al. (1972, Combinatory logic, vol. ii) in the form of "polymorphic type assignment" for untyped lambda-terms. Types are assigned after the fact to what is, in modern terminology, a dynamic language. Interest in type assignment was revitalized by the proposals of Bracha et al. (1998, OOPSLA) and Bank et al. (1997, POPL) to enrich Java with polymorphism (generics), which in turn sparked the development of other languages, such as Scala, with similar combinations of features. In such a setting, where the target language already has a monomorphic type system, it is desirable to compile polymorphism to dynamic typing in such a way that as much static typing as possible is preserved, relying on dynamics only insofar as genericity is actually required. The basic approach is to compile polymorphism using embeddings from each type into a universal "top" type, ID, and partial projections that go in the other direction. This scheme is intuitively reasonable, and, indeed, has been used in practice many times. Proving its correctness, however, is non-trivial. This paper studies the compilation of System F to an extension of Moggi's computational meta-language with a dynamic type and shows how the compilation may be proved correct using a logical relation.
As multicore computing is now standard, it seems irresponsible for constraints researchers to ignore the implications of it. Researchers need to address a number of issues to exploit parallelism, such as: Investigatin...
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Combining theory and practice, Website Design and Development with HTML5 and CSS3 is aimed at both beginners who want to design their first website, and experienced developers who want to consolidate their technical s...
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ISBN:
(数字)9781119885122
ISBN:
(纸本)9781786306968
Combining theory and practice, Website Design and Development with HTML5 and CSS3 is aimed at both beginners who want to design their first website, and experienced developers who want to consolidate their technical skills. This book addresses the theoretical aspects of HTML5 and CSS3, including: HTML elements, semantic containers, semantic text formatting, multimedia elements, forms, tables, definition and integration of CSS styles, text formatting, and container and box styles. It also encompasses a practical section which presents the process of creating a website, as well as the key rules to apply in order to not only achieve project success, but also to meet user needs. Illustrated by numerous examples, this book includes corrected practical work, structured according to an evolutionary logic ranging from the design of a simple HTML5 page to the creation of a professional website.
Vehicular network is regarded as an important part of the Intelligent Transportation System (ITS). However, with the increasing number of vehicular applications, it is a challenge to meet the demands of both communica...
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ISBN:
(纸本)9781509032068
Vehicular network is regarded as an important part of the Intelligent Transportation System (ITS). However, with the increasing number of vehicular applications, it is a challenge to meet the demands of both communication and computation. Fog computing can provide mobile users with the demanded services through low latency and short-distance local connections. This paper investigates the optimal deployment and dimensioning (ODD) of fog computing supported vehicular network. The ODD problem is important for fog computing from theory to practical deployment. We formulate the problem as an integer linear programming (ILP) and the objective is to minimize the cost of deployment. Two different models based on coupling and decoupling fog devices with Roadside Units (RSUs) are developed and the results show that the decoupling model is a way more cost-effective in practice.
Scheduling problems such as job shop scheduling and timetabling can be expressed as constraint satisfaction problems (CSPs) and so are, at least in theory, amenable to solution by standard constraint satisfaction algo...
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Scheduling problems such as job shop scheduling and timetabling can be expressed as constraint satisfaction problems (CSPs) and so are, at least in theory, amenable to solution by standard constraint satisfaction algorithms. Unfortunately, CSPs (and most scheduling problems) are in general NP-complete. Hence we should expect the time required to solve a CSP to increase exponentially with the size of the problem, so that in practice there will be a limit to the size of problem which can be solved in a reasonable time. One approach to tackling a problem which is too large to be solved exactly by a standard search algorithm is to devise algorithms which abandon the idea of a systematic search of the entire search space. Typically these algorithms form an initial solution which is deficient in some way (infeasible or suboptimal), and attempt to improve it by making local changes or repairs. The algorithm moves through a sequence of solutions, each of which is a neighbour, in some sense, of the preceding one. Several papers have described repair-based heuristic methods of this kind for constraint satisfaction and related problems. The author describes a heuristic of the same type, originally developed as part of the ROSA system (B.M. Smith, S. Bennett, 1992), which produces weekly anaesthetists' rotas for a hospital anaesthetics department.< >
ProVerif over-approximates the attacker’s power to enable verification of processes under replication. Unfortunately, this results in ProVerif finding false attacks. This problem is particularly common in protocols w...
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Decision support systems play an important role in medical fields as they can augment clinicians to deal more efficiently and effectively with complex decision-making processes. In the diagnosis of headache disorders,...
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The high level of complexity of integrated circuits is one of the main problems in modern electronic practices. These circuits can only be explained on a theoretical level or require expensive and specialized equipmen...
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The high level of complexity of integrated circuits is one of the main problems in modern electronic practices. These circuits can only be explained on a theoretical level or require expensive and specialized equipment. The traditional teaching of electronics based on discrete components or LSI integrated circuits as logic gates or flip-flops is being clearly outdated, and runs the risk of creating a gap between theory and practice that goes against the spirit of professional training. This article presents a hardware and software set of components designed for advanced electronic practices whose centerpiece is a microcontroller that connects different peripherals such as analog-to-digital converters, keyboards, displays of different technologies (including latest graphics LCD modules), power and different communications interfaces and protocols. This modular architecture can be used in basic training modules (such as analog and digital electronics) but also in more specific modules such as sound, home automation, robotics and industrial control. The components used are cheap and modules can be built in the schools to reduce its cost. The schematics and printed circuit boards are free to use and for their design has been used the open source program Kicad. The microcontroller programming environment is based on Eclipse-SDCC, which is also open source and multiplatform. This system can be used for demonstrations and school practices. The system can also be used as a platform for teaching C programming or assembler for microcontrollers. All the elements have been developed at the institute "Escolas Proval" of Nigrán (Pontevedra) by a team of electronics teachers and students. Over the last years have been designed and built some of the modules and it is planned to continue making new ones based on the training needs that will be detected and new professional qualifications currently under implementation.
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