We have developed and implemented a computer-based method to generate and enumerate all conjugate forms of acyclic organic compounds. These algorithms are used in a new approach for the estimation of thermodynamic and...
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We have developed and implemented a computer-based method to generate and enumerate all conjugate forms of acyclic organic compounds. These algorithms are used in a new approach for the estimation of thermodynamic and physical properties of acyclic organic compounds from their molecular structure. The approach is based on the contributions of Atoms and Bonds in the properties of Conjugate forms (ABC) of a compound and has produced more accurate results than group-contribution methods. Generating all conjugate forms of the molecule whose properties we wish to estimate is necessary in the application of this technique. The use of symbolic computing environments allows the flexible representation and manipulation of molecular structures. Atoms, bonds, molecules, and other entities are represented as interconnected objects. The generation, comparison, and analysis of conjugates are carried out through computer-based manipulation of the objects and their interconnections.
Reflective architectures support the incremental development of object-oriented systems, but they are mostly implemented in the interpretation-based languages. This paper presents a new reflective architecture, XDRC++...
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Reflective architectures support the incremental development of object-oriented systems, but they are mostly implemented in the interpretation-based languages. This paper presents a new reflective architecture, XDRC++,for reflective programming in the C++ language. XDRC++ provides a run-time system constructed by a collection of built-in classes, and the reflective facilities to switch between methods and meta-methods at run-time. All these facilities are constructed in an integrated way using only the compile-time mechanisms of C++. In XDRC++ we propose a new viewpoint that the object identity is an object. The identity of an object is then a meta-object carrying on the type-free reflective computations about the object. Two prototypes of XDRC++ for distinct C++ compilers have been implemented
INTRODUCTION object-oriented programming is proving to be quite useful in many areas which have not been served well by more conventional *** fact,any real world object can be modeled in an objectoriented *** real-wo...
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INTRODUCTION object-oriented programming is proving to be quite useful in many areas which have not been served well by more conventional *** fact,any real world object can be modeled in an objectoriented *** real-world objects may exist and do things concurrently,object-oriented systems also show great potential for exploiting concurrence/*** many object-oriented languages currently in use are sequential(such as C++,Smalltalk-80, Eiffel).How to implement object-oriented languages on parallel systems is still a promising research topic.
A concurrent object-oriented programming (COOP) model is presented for computer-aided engineering using a blackboard architecture. The basic components of the model are a hierarchy of tasks, global and local controlle...
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作者：
ODERSKY, MIBM Research
T J Watson Research Center PO Box 704 Yorktown Heights NY 10594 USA
The paper presents an extension of MODULA-2 for objectorientedprogramming. After presenting a set of criteria for object-oriented languages, it discusses several possible strategies for extending MODULA-2. One of the...
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The paper presents an extension of MODULA-2 for objectorientedprogramming. After presenting a set of criteria for object-oriented languages, it discusses several possible strategies for extending MODULA-2. One of these strategies is then further developed and formalized in a new programming notation, MODULA-90.
This note explains why general multiple inheritance is contra-intuitive in object-oriented programming. Firstly, we show some problems which occur when using general multiple inheritance. Secondly, we analyze the purp...
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This note explains why general multiple inheritance is contra-intuitive in object-oriented programming. Firstly, we show some problems which occur when using general multiple inheritance. Secondly, we analyze the purposes for which multiple inheritance is used in large and complex software systems according to our experience. This provides arguments for our rejection of general multiple inheritance. Instead of it, a more specific multiple inheritance scheme called mixin should be provided. On the one hand, this would secure that the programmer's intuition and the behaviour of the inheritance algorithm always agree and, on the other hand, we obtain the same performance the single inheritance languages do.
The paper tries to identify the essential characteristics of object-oriented programming, and then asks which features, beyond new terminology, will justify a programming language being called ‘object-oriented’. Usi...
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The paper tries to identify the essential characteristics of object-oriented programming, and then asks which features, beyond new terminology, will justify a programming language being called ‘object-oriented’. Using these criteria, the ‘object-orientedness’ of MODULA-2 is investigated. Concluding that the language allows, but does not support, this style of programming, minimal additions that would be necessary to satisfy the characteristics of objectorientation are considered.
An interesting and little documented problem is the influence of a design methodology on the program architecture. In this case study, we compared two design methodologies and their impact on both development process ...
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An interesting and little documented problem is the influence of a design methodology on the program architecture. In this case study, we compared two design methodologies and their impact on both development process and the resulting program architecture. The methodologies are object-based variants of refinement methodology and structured design, respectively. Both methodologies were applied to the same problem (a library system of less than 1000 lines of Ada code), and the results were compared. Substantial differences between the two resulting architectures are analysed and discussed.
Design for manufacturability has been proved to be a solution that avoids the problems created by design not amenable to manufacturing. The designer should be aware of the manufacturing constraints to achieve the desi...
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Design for manufacturability has been proved to be a solution that avoids the problems created by design not amenable to manufacturing. The designer should be aware of the manufacturing constraints to achieve the design for manufacturability. The rapid change in printed circuit board manufacturing with the induction of surface mounted components and robotic assembly has changed the scenario of the design. The high-density packaging capability of surface mounted technology has contributed enormously to the development of new trends in printed wiring board manufacturing. PWBMA, Printer Wiring Board Manufacturability Advisor (printed wiring board is another name for printed circuit board), a knowledge-based system, is developed to capture this new technology and its interaction with the existing through-hole mounting technology. Rules and guidelines pertaining to manufacturability of the board are formulated and incorporated into the knowledge base in building the system, which is built on an object-oriented paradigm. The importance of the object-oriented approach, the implementation of the object-oriented paradigm, object-oriented programming using Smalltalk-80, and the hierarchical rule structure paradigm are discussed. The implementation of meta-level to increase the efficiency of the system is also presented. Furthermore a rating system is introduced to rank various designs. PWBMA is capable of suggesting design modifications at the early stage of design to eliminate the manufacturing problems in the later phase of board production. The system is very easy to use with a broad user interface.
A recent paradigm in software engineering is object-oriented software development. However, object-oriented methods still remain ad hoc, and the process of deriving an object-oriented design from the early analysis ha...
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A recent paradigm in software engineering is object-oriented software development. However, object-oriented methods still remain ad hoc, and the process of deriving an object-oriented design from the early analysis has not yet been formalised. In this paper, we advocate deriving a formal specification from informal requirements, conducting static analysis on the formal functional specifications to reason about the intended behaviour of the system, and then transforming the flat specification to an object-oriented design. The transformations discussed in this paper can be formalised and can be applied to any model-oriented specification to get a corresponding object-oriented design. The methodology is illustrated for a simple library management system using the model-oriented specification technique VDM.
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