Windows程序运行于Linux系统的技术

在Linux系统上运行Windows程序,是Linux争夺桌面应用领域面临的技术难题.对Windows设备驱动程序和应用程序运行于Linux系统的技术现状及发展趋势作了综合阐述.对于兼容Windows设备驱动程序,目前Linux系统仅能运行Windows网络接口设备驱动程序;对于兼容Windows应用程序,目前可采取的技术有代码重构、跨平台编译、软件虚拟机和API仿真等技术.这些技术因各自的局限性而无法撼动Windows在桌面领域的统治地位,使得开发支持Windows设备驱动程序和应用程序的Linux兼容内核成为提高桌面Linux市场竞争力的必然趋势.     

A functional approach to database updates

PFL is a functional database language in which functions are defined equationally and bulk data is stored using a special class of functions called selectors. It is a lazy language, supports higher-order functions, has a strong polymorphic type inference system, and allows new user-defined data types and values to be declared. All functions, types and values persist in a database. Functions can be written which update all aspects of the database: by adding data to selectors, by defining new equations, and by introducing new data types and values. PFL is “semi-referentially transparent”, in the sense that whilst updates are referentially opaque and are executed destructively, all evaluation is referentially transparent. Similarly, type checking is “semi-static” in the sense that whilst updates are dynamically type checked at run time, expressions are type checked before they are evaluated and no type errors can occur during their evaluation.

In this paper we examine the expressiveness of PFL with respect to updates, and illustrate the language by developing a number of general purpose update functions, including functions for restructuring selectors, for memoisation, and for generating unique system identifiers. We also provide a translation mechanism between Datalog programs and equations, and show how different Datalog evaluation strategies can be supported.     

A decision support system for college selection

In this changing society the importance of higher education is increasing more than ever before. The selection of an appropriate university or college is of vital importance to the student for acquisition of proper educational experience. There are thousands of universities and colleges in the United States and Canada. The information available to students about each college is plentiful but is rather tedious to be obtained. The decision process of college selection is further complicated by many factors such as tuition, location, rank, size of the universities, and so forth. These factors play an important role in the final selection of a college. Therefore, a computer-based decision support system is developed in this paper to help users make better decisions in the selection of a college.

This college selection decision support system is designed to be menu-driven and highly user-friendly with a “Help” utility. Many “what-if” scenarios are also available in this system. It can be run on any IBM XT/AT or compatible machines with a DOS environment. It will allow users to make better decisions in their college selection process.     

Program derivation in type theory: A partitioning problem

Martin-Löf's type theory is a theory in which one can write both specifications and programs. By interpreting propositions as types, predicate logic is available when formulating a specification. The rules of type theory are formulated as tactics which makes a “top down” construction of programs possible. These ideas are illustrated by a formal derivation of a program for a partitioning problem.     

Performing a course material enhancement process with asynchronous interactive online system

Online systems have come to be heavily used in education, particularly for online learning and collecting information not otherwise readily available. Most e-learning systems, including interactive learning systems, have been designed to “push” course materials to students but rarely to “collect” or “pull” ideas from them. The interactive mechanisms in proposed instructional design models, however, prevent many potential designers from improving course quality, even though some believe that the learning experience and the comments of students are important for enhancing course materials. As well, students could actually contribute to instructional design.This paper presents a course material enhancement process that elicits ideas from students by encouraging students to modify course materials. This process had been tested on different higher education programs, both graduate and undergraduate. It aims to understand which programs’ students have a higher willingness to participate in this work and if they can benefit from this process. To facilitate this research, an asynchronous interaction system, teacher digital assistant (TDA), was designed for teachers to receive responses, recommendations, and modified materials from students at any time. The major advantage of this process is that it could embed students’ thoughts into the course material to improve the curriculum, which can benefit future students.     

PLANET: A simulation approach to PERT

PLANET is a modification of PERT which permits use of arbitrary activity duration distributions in Monte-Carlo simulations which provide approximate distributions for completion times for project milestones and which identifies three classes of slacks for activities: total slack, free slack, and incremental slack (a new concept). The concept of “critical path” is supplemented by that of “probability of criticality” for each activity. This provides an improved basis for reallocation of resources using a “rob Peter to pay Paul” principle. The algorithms used are designed to have running times linearly proportional to the size of the underlying PERT network so PLANET should execute efficiently, even on large networks.     

MESTRIMAN: An expert system for medical triage and clinical management of patients in catastrophes

Providing appropriate medical assistance in catastrophes is not an easy problem to cope with. Some of the problems involved in the task are the diversity of catastrophes and medical emergencies, the insufficient number of experts usually available during a given catastrophe, the necessity of improving medical performace time, and the lack of coordination of the resources that may be used. In this respect, the application of both communication and computer technologies may provide important and useful support in most of the different phases involved in the management of catastrophes. In this paper we describe “MESTRIMAN,” an expert system designed to provide medical assistance in catastrophes. “MESTRIMAN” is a module of SIAC, a computer system designed to manage relevant information and data about a wide range of different catastrophes and capable of performing as the central coordinator of the available resources.     

Solutions to Industrial Engineering problems using integrated software environments

The development of word processing systems and the spreadsheet environment marked the beginning of the professional computing movement. For the first time, programs were available that were both highly functional and highly usable, even by non-computer people. The next group of “hot” programs in the business market were “integrated” packages providing a combination of word processing, spreadsheet, database, graphics, and telecommunications. Unfortunately, these integrated packages have not displaced such single purpose programs as Lotus 1-2-3, dBase and WordPerfect as the dominant forces in desktop computing. Integrated packages are generally perceived as complex, cumbersome, and difficult to master. An important point to note, however, is that high proficiency is not necessary; successful users of commercial software seldom know or use more that 40% of a programs functionality.

This paper addresses the use of integrated software packages to solve Industrial Engineering problems. More specifically, examples are presented demonstrating the use of Ashton Tate's Framework II to solve production and operations management problems. Sample applications include forecasting, after tax economic analysis, and data storage and retrieval, demonstrating the advantages of linking word processing, spreadsheets, and databases.     

Automatically maintaining navigation sequences for querying semi-structured web sources

A substantial subset of Web data has an underlying structure. For instance, the pages obtained in response to a query executed through a Web search form are usually generated by a program that accesses structured data in a local database, and embeds them into an HTML template. For software programs to gain full benefit from these “semi-structured” Web sources, wrapper programs must be built to provide a “machine-readable” view over them. Since Web sources are autonomous, they may experience changes that invalidate the current wrapper, thus automatic maintenance is an important issue. Wrappers must perform two tasks: navigating through Web sites and extracting structured data from HTML pages. While several works have addressed the automatic maintenance of data extraction tasks, the problem of maintaining the navigation sequences remains unaddressed to the best of our knowledge. In this paper, we propose a set of novel techniques to fill this gap.     

多功能混凝土超声波检测仪软件设计与实现

为自主研制的多功能混凝土超声波检测仪开发了一套基于Windows平台的数据采集与分析软件.该软件采用动态链接库技术将底层硬件访问函数与Windows应用程序进行了有效分离,利用DMA方式和多线程技术进行了数据的实时采集,设计了友好的人机界面和各种容错及防错措施,提高了系统的稳定性.该软件在多个实际工程中得到应用,使用效果良好.     

基于RTX的建模与实时仿真软件YH-RTSIM的设计

为了满足新型飞行器半实物仿真更高的实时性要求,基于Windows的实时扩展包RTX开发建模与实时仿真软件YH-RTSIM,设计了由仿真建模集成环境、Windows进程和RTSS进程组成的软件结构,不仅可提高实时性,而且原有用户的仿真程序只需很小的修改就可编译运行。设计了基于共享内存的进程间通信算法来实现实时数据存储和显示,设计了帧时间控制算法保证精确的帧时间。测试和应用表明:YH-RTSIM运行正确, 仿真帧时间的误差为-0.0004ms~0.0004ms,小于1μs (0.001ms),能满足飞行器半实物仿真的需要。     

SHEARCALC—a computer program for the calculation of volume change and mass transfer in a ductile shear zone

SHEARCALC was created to automate mass balance calculations in an alteration zone. The program can be most successfully applied to ductile shear zones, where an undeformed wall rock is transformed into a fine-grained mylonite via several protomylonitic stages. The program was written in Visual Basic 6.0 and offers numerous features typical for Windows™ applications to increase the user friendliness. SHEARCALC consists of an input part for entering sample names, specific weights and chemical data of the investigated rocks as well as for selecting immobile elements and scaling factors for an appropriate display of the data in the isocon diagram. In the calculation part, the slope of the isocon and related volume changes between two specific stages of alteration are computed. Additionally, gains and losses of the main elements during deformation are expressed by respective mass transfer equations. As a special feature, SHEARCALC contains an extensive diagram section, where the user can select between three chart types. Besides the classical isocon diagram, mass changes of elements are also displayed in specific two- or three-dimensional bar charts. Element behaviour along a transsect through the shear zone is documented by two- or three-dimensional profile graphs. SHEARCALC is a stand-alone application adapted to modern Windows™ operating systems and therefore differs from many available programs in the geoscience which only run in DOS mode.     

Code Annotation for Safe and Efficient Dynamic Object Resolution

The execution time of object oriented programs can be drastically reduced by transforming “non escaping” objects into a collection of its component scalar data fields. But for languages that support dynamic linking, this kind of optimization (which we call “object resolution”) can usually only be performed at runtime, when the entire program is available for analysis. In such cases, the resulting performance increases will be offset by the additional costs that arise during the analysis and restructuring phases.In this paper, we describe work in progress, which provides an annotation technique that reduces the runtime overhead required for performing object resolutions. Our method performs a partial static escape analysis of each class at compile-time and then annotates the intermediate representation of that class with information which the just-in-time (JIT) compiler can use for object resolution. We apply this technique to the safe TSA intermediate representation, producing a simple extension to safe TSA's type system that guarantees a safe and verifiable transmission of the annotated program.     

A least squares algorithm for a mixture model for compositional data

The estimation of a model for compositional data is studied where the data are approximated by a mixture of latent compositions. This model is variously known as “endmember analysis” or “latent budget analysis”. Two estimation procedures are available. The first uses a procedure which is incorrect in the sense that, although it claims to be a least squares procedure, it does not always minimize a least squares criterion. The second uses a maximum likelihood procedure starting from assumptions that are often violated for compositional data. In this paper we propose a constrained (weighted) least squares procedure for the estimation of the model.     

…On the direct programming of CNC milling equipment

This paper discusses the use of expert software which directly programs Computer Numerical Control (CNC) milling equipment from engineering style Computer-Aided-Design (CAD) drawings. Currently available software provides only semi-automatic programming based upon strict drawing format, user selected tools and user supplied tool path information. (DPS) derives part feature, tool selection, and tool path from “loosely” specified CAD drawings without direct user control. Other CNC programming methods are error prone and are slow to produce accurate CNC programs. The new technology eliminates programming error and completes processing in seconds rather than hours or days, thus providing for a true Computer Integrated Manufacturing (CIM) environment. DPS is in use on various 2D and 3D milling environments as well as on several types of small or personal computers and CAD systems. Additional systems and environments can be supported. DPS is designed to operate efficiently with AutoDesk, Inc.'s AutoCAD and Hewlett Packard 9000/320 ME-10 (HP-UX) based drawings. An additional implementation is running on SCO XENIX/386.

This paper presents technology and productivity improvements for various classes of DPS systems available today. Examples of actual use, productivity improvements and product dependencies are discussed and illustrated.     

The multimod application framework: a rapid application development tool for computer aided medicine

This paper describes a new application framework (OpenMAF) for rapid development of multimodal applications in computer-aided medicine. MAF applications are multimodal in data, in representation, and in interaction. The framework supports almost any type of biomedical data, including DICOM datasets, motion-capture recordings, or data from computer simulations (e.g. finite element modeling). The interactive visualization approach (multimodal display) helps the user interpret complex datasets, providing multiple representations of the same data. In addition, the framework allows multimodal interaction by supporting the simultaneous use of different input-output devices like 3D trackers, stereoscopic displays, haptics hardware and speech recognition/synthesis systems. The Framework has been designed to run smoothly even on limited power computers, but it can take advantage of all hardware capabilities. The Framework is based on a collection of portable libraries and it can be compiled on any platform that supports OpenGL, including Windows, MacOS X and any flavor of Unix/linux.     

SweetWiki: A semantic wiki

Everyone agrees that user interactions and social networks are among the cornerstones of “Web 2.0”. Web 2.0 applications generally run in a web browser, propose dynamic content with rich user interfaces, offer means to easily add or edit content of the web site they belong to and present social network aspects. Well-known applications that have helped spread Web 2.0 are blogs, wikis, and image/video sharing sites; they have dramatically increased sharing and participation among web users. It is possible to build knowledge using tools that can help analyze users’ behavior behind the scenes: what they do, what they know, what they want. Tools that help share this knowledge across a network, and that can reason on that knowledge, will lead to users who can better use the knowledge available, i.e., to smarter users. Wikipedia, a wildly successful example of web technology, has helped knowledge-sharing between people by letting individuals freely create and modify its content. But Wikipedia is designed for people—today's software cannot understand and reason on Wikipedia's content. In parallel, the “semantic web”, a set of technologies that help knowledge-sharing across the web between different applications, is starting to gain attraction. Researchers have only recently started working on the concept of a “semantic wiki”, mixing the advantages of the wiki and the technologies of the semantic web. In this paper we will present a state-of-the-art of semantic wikis, and we will introduce SweetWiki, an example of an application reconciling two trends of the future web: a semantically augmented web and a web of social applications where every user is an active provider as well as a consumer of information. SweetWiki makes heavy use of semantic web concepts and languages, and demonstrates how the use of such paradigms can improve navigation, search, and usability.     

Linux 与Windows 在桌面领域的互操作性

Linux和Windows都是计算机操作系统领域中的技术热点,两者实现互操作有利于在竞争中共同推动操作系统技术向纵深发展。针对Linux和Windows在桌面领域中的互操作问题,文中作了系统的阐述。在桌面领域,Linux和Windows可以采用API仿真等虚拟化技术或修改操作系统源代码的方法来互运行对方程序,可以采用开放、通用与统一的数据文件格式标准来互处理数据文件,可以采用内核空间文件系统机制或用户空间文件系统机制来互访问文件系统等。