The advent of structural genomics initiatives has led to a pressing need for high-throughput macromolecular structure determination. To accomplish this, new methods and inevitably new software must be developed to acc...
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The advent of structural genomics initiatives has led to a pressing need for high-throughput macromolecular structure determination. To accomplish this, new methods and inevitably new software must be developed to accelerate the process of structure solution. To minimize duplication of effort and to generate maintainable code efficiently, a toolbox of basic crystallographic software components is required. The development of the Computational Crystallography Toolbox (cctbx) has been undertaken for this purpose. In this paper, the fundamental requirements for the cctbx are outlined and the decisions that have lead to its implementation are explained. The cctbx currently contains algorithms for the handling of unit cells, space groups and atomic scatterers, and is released under an Open Source license to allow unrestricted use and continued development. It will be developed further to become a comprehensive library of crystallographic tools useful to the entire community of software developers.
This paper presents a description of the reorganization of a geometric modeler, MG, designed to support new capabilities of a topological module (CGC) that allows the detection of closed-off solid regions described by...
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This paper presents a description of the reorganization of a geometric modeler, MG, designed to support new capabilities of a topological module (CGC) that allows the detection of closed-off solid regions described by surface patches in non-manifold geometric models defined by NURBS. These patches are interactively created by the user by means of the modeler's graphics interface, and may result from parametric-surface intersection in which existing surface meshes are used as a support for a discrete definition of intersection curves. The geometry of realistic engineering objects is intrinsically complex, usually composed by several materials and regions. Therefore, automatic and adaptive meshing algorithms have become quite useful to increase the reliability of the procedures of a FEM numerical analysis. The present approach is concerned with two aspects of 3D FEM simulation: geometric modeling, with automatic multi-region detection, and support to automatic finite-element mesh generation. (C) 2002 Elsevier Science Ltd. All rights reserved.
From the Publisher: This book is for anyone who wants to learn how to use VisualBasic .NET for developing business applications. 5 WAYS THE CONTENT GIVES YOU A PROFESSIONAL START If you're a beginner, you'll l...
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ISBN:
(纸本)9781890774158
From the Publisher: This book is for anyone who wants to learn how to use VisualBasic .NET for developing business applications. 5 WAYS THE CONTENT GIVES YOU A PROFESSIONAL START If you're a beginner, you'll learn how to code, test, and debugobject-oriented Visual Basic programs in the first seven chapters. That'ssection 1 of this book, and no other book gets you started that fast withsuch a wide range of skills. In section 2, you'll learn how to develop graphical user interfaces at aprofessional level. This includes the use of common controls, multi-documentinterfaces, and GUI enhancements like menus, toolbars, and help information. In section 3, you'll learn how to use the .NET classes to work with dates,strings, arrays, collections, structures, files, and XML. You'll also learnthe skills you need for object-oriented programming. These are theprogramming skills that every professional should have. In section 4, you'll learn how to use *** and the disconnected dataarchitecture of the .NET platform to develop database applications withbound controls, queries, and parameterized queries. Although there's a lotmore to database programming than that, this will get you off to a terrificstart. In section 5, you'll learn how to develop web applications and create anduse web services. Here again, there's a lot more to web programming thanthat, but this will get you started right. 4 WAYS OUR INSTRUCTIONAL APPROACH INSURES YOUR SUCCESS To help you learn how to develop applications at a professional level, thisbook presents 18 business applications as examples. That way, you can seethe relationships between the Visual Basic code, objects, properties,methods, and events that an application requires, which is essential to yourunderstanding. In contrast, most competing books present trivialapplications that have little resemblance to applications in the real world,and that limits your learning potential. To solidify your skills, the exercises at the end of each chapter guide
For realizing the self-adaptive Simulation of the whole transient, the class Structure of the power system elements is researched by object-oriented Modeling (OOM). By taking generator for example, this paper builds t...
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ISBN:
(纸本)0780374908
For realizing the self-adaptive Simulation of the whole transient, the class Structure of the power system elements is researched by object-oriented Modeling (OOM). By taking generator for example, this paper builds the object-oriented self-adaptive models of elements and realizes the transform of subelasses. The object-oriented technology is also used to implement the Simulating program. The simulating results verify that problems caused by the function-oriented method are solved.
object-oriented programming is an alternative to overcome the problems associated with the development, maintenance and update of large software by electrical utilities. However many applications in the electrical ind...
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object-oriented programming is an alternative to overcome the problems associated with the development, maintenance and update of large software by electrical utilities. However many applications in the electrical industry depend critically on the computational efficiency of the implementation. This paper applies the object-oriented approach to the problem of power system dynamics simulation. A decomposition of the electric power system into classes, suitable to include all elements required in this problem, is presented. A structure for linear systems solution aiming computational efficiency for large-scale systems applications, is proposed. Tests using four equivalents of the South-Southeastern Brazilian interconnected power system are carried out. The performance of the object-oriented program, developed in C++, is assessed in several computers. Real-time simulation was achieved for medium-sized power systems in lower cost high performance computers. The implementation is compared with an industry program written in Fortran and similar performances are achieved.
This paper presents a description of the reorganization of a geometric modeler, MG, designed to support new capabilities of a topological module (CGC) that allows the detection of closed-off solid regions described by...
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This paper presents a description of the reorganization of a geometric modeler, MG, designed to support new capabilities of a topological module (CGC) that allows the detection of closed-off solid regions described by surface patches in non-manifold geometric models defined by NURBS. These patches are interactively created by the user by means of the modeler's graphics interface, and may result from parametric-surface intersection in which existing surface meshes are used as a support for a discrete definition of intersection curves. The geometry of realistic engineering objects is intrinsically complex, usually composed by several materials and regions. Therefore, automatic and adaptive meshing algorithms have become quite useful to increase the reliability of the procedures of a FEM numerical analysis. The present approach is concerned with two aspects of 3D FEM simulation: geometric modeling, with automatic multi-region detection, and support to automatic finite-element mesh generation. (C) 2002 Elsevier Science Ltd. All rights reserved.
Recent popularity of Java programming language has brought the automatic dynamic memory management (a.k.a., the garbage collection) into the mainstream, Traditional garbage collectors suffer from long garbage collecti...
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ISBN:
(纸本)0780373715
Recent popularity of Java programming language has brought the automatic dynamic memory management (a.k.a., the garbage collection) into the mainstream, Traditional garbage collectors suffer from long garbage collection pauses (stop-the-world mark-sweep algorithm) or inability of collecting cyclic garbage (reference counting approach). Generational garbage collection, however, is based only on the weak generational hypothesis that most objects die young. In this paper, the performance evaluation of a new multithreaded concurrent generational garbage collector (MCGC) based on mark-sweep with the assistance of reference counting is reported. The MCGC can take advantage of multiple CPUs in an SMP system and the merits of light weight processes. Furthermore, the long garbage collection pause can be reduced and the garbage collection efficiency can be enhanced. Measurement results indicate that the MCGC improves the garbage collection pause time up to 96.75% over the traditional stop-the-world mark-sweep garbage collector. Moreover, the MCGC receives minimal time and space penalties as shown in the report of the total execution time, the memory footprint and the sticky reference count rate.
As object-oriented paradigm becomes the mainstream paradigm on software development, due to its attractive features that can effectively divide a complex software problem into several independent modules, one of the o...
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ISBN:
(纸本)0780374908
As object-oriented paradigm becomes the mainstream paradigm on software development, due to its attractive features that can effectively divide a complex software problem into several independent modules, one of the object-oriented languages - Java, becomes popular in recent years because it is widely used in the rapidly growing Internet computing. However, similar to other object-oriented languages, Java has a big drawback of poor performance. One of the main causes of the performance deficiency is the extensive use of dynamic memory allocations and deallocations during object or array creations and destructions. Even a simple Othello applet game easily requires half a million of memory allocations for only one game play. After analysis on the memory allocation behavior of Java programs, it is concluded that about 99% of the allocations are of sizes less than 1024 bytes. The analysis also shows that most of the allocated chunks in small size will survive only a very short period of time and after they are garbage collected, they can be reused in the very near future. This implies the memory allocation/deallocation pattern in Java is bounded to a certain kind of locality. The information presented in this paper is a reference for designing an efficient hardware memory allocation/deallocation unit.
作者：
Jørgensen, S.E.DFH
Institute A University Park 2 Environmental Chemistry Copenhagen East Denmark 2100 Denmark
This paper presents an overview of the application of models on aquatic ecosystems. More than 17% of the models published in the focal journal in the field, Ecological Modelling, are aquatic ecosystem models. An incre...
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This paper presents an overview of the application of models on aquatic ecosystems. More than 17% of the models published in the focal journal in the field, Ecological Modelling, are aquatic ecosystem models. An increasing number of papers are dealing with the theoretical aspects of modeling--new modeling approaches and techniques, how models can be used to reveal ecosystem properties, and how models can better reflect the properties of ecosystems. This development implies that today we have more types of models. The characteristics, the advantages, and the disadvantages of these model types are presented briefly. The selection criteria for the presented model types are discussed, and the application of these types to models for aquatic ecosystems is reviewed. A recent improvement in model calibration of particular interest for aquatic ecosystems is presented, and the perspectives resulting from this new calibration procedure and from possible hybrids of the presented model types are discussed.
From the Publisher: COM and .NET Interoperability provides a complete overview on the process of building .NET applications which interact (interoperate) with existing COM code. Before digging into that critical topic...
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ISBN:
(纸本)9781590590119
From the Publisher: COM and .NET Interoperability provides a complete overview on the process of building .NET applications which interact (interoperate) with existing COM code. Before digging into that critical topic, Andrew offers a concise overview of the COM architecture, and provides examples using various COM frameworks (C++, ATL, and VB 6.0). Next, the reader will learn the core aspects of the .NET platform and come to understand the use of both C# and VB .NET during the process. With these primers aside, the remainder of the book covers numerous interoperability issues including interacting with the Windows API, event programming and the process of building custom code conversion utilities.
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