基于模拟对象Mock Object的单元测试研究

在软件测试中,单元测试不仅能够优化软件系统设计,还大大简化了功能测试的测试量。但是在一些情况下进行单元测试比较困难,本文引入了模拟对象Mock Object的概念,利用Mock Object进行单位测试,解决了传统单元测试中存在的一些问题。     

Web应用系统中的MOCK测试技术

近年来Web应用的市场占有率越来越高,Web开发技术也得到了飞速的发展。然而针对Web应用系统的测试却不够成熟。为了提高Web应用的开发效率和系统的稳定性,研制出适用于Web应用的测试理论与框架日益迫切。MOCK测试技术是通过构建模拟对象实现对单元测试中的被测模块孤立进行测试的技术。而本文针对Web应用系统的分布式等特性,结合Web开发的实际需求,对传统软件开发中的MOCK测试技术进行改进,并且提出了Web应用下MOCK自动化测试工具的系统架构,为Web应用系统的测试提供了一个高效的解决方案。     

Mapping objects

We present a technique that is based on volatile mapping objects and enables wrappers-based mediation architectures to describe bi-directional (read–write) interschema mappings of multiple, disparate data sources. We describe the structure of these mapping objects, explain how they work, and compare them to other traditional techniques used for describing schema mappings in data-mediation systems.     

Graphical objects

We introduce the concept of graphical objects, the abstraction paradigms to study them, and their applications in computer graphics. Intuitively, graphical objects encompass all the entities manipulated in a graphics system. This notion makes it possible to unify similar research topics appearing in the literature separately. We study the problem of object metamorphosis, which includes the problem of image metamorphosis. Although we are not primarily concerned with implementation issues in this paper, the concepts we introduce can be exploited for system design and development that use object-oriented programming.     

Distributed logic objects

This paper presents a language based on the logic programming paradigm that supports objects, messages and inheritance. The object-oriented extension is fairly simple: objects are clusters of processes, objects' state is represented by logical variables, message-passing communication between objects is performed via multi-head clauses, and inheritance is mapped into clause union. The language implementation is obtained by translating logic objects into a concurrent logic language based on multi-head clauses, taking advantage of its distributed implementation on a massively parallel architecture. The runtime support realizes some interesting features such as intensional messages and the transparency of object allocation, object migration and parallelism.     

Classifying dynamic objects

For robots operating in real-world environments, the ability to deal with dynamic entities such as humans, animals, vehicles, or other robots is of fundamental importance. The variability of dynamic objects, however, is large in general, which makes it hard to manually design suitable models for their appearance and dynamics. In this paper, we present an unsupervised learning approach to this model-building problem. We describe an exemplar-based model for representing the time-varying appearance of objects in planar laser scans as well as a clustering procedure that builds a set of object classes from given observation sequences. Extensive experiments in real environments demonstrate that our system is able to autonomously learn useful models for, e.g., pedestrians, skaters, or cyclists without being provided with external class information.     

Detecting moving objects

The detection of moving objects is important in many tasks. This paper examines moving object detection based primarily on optical flow. We conclude that in realistic situations, detection using visual information alone is quite difficult, particularly when the camera may also be moving. The availability of additional information about camera motion and/or scene structure greatly simplifies the problem. Two general classes of techniques are examined. The first is based upon the motion epipolar constraint—translational motion produces a flow field radially expanding from a focus of expansion (FOE). Epipolar methods depend on knowing at least partial information about camera translation and/or rotation. The second class of methods is based on comparison of observed optical flow with other information about depth, for example from stereo vision. Examples of several of these techniques are presented.A preliminary version of this article appeared in The Proceedings of the First International Conference on Computer Vision, London, June 1987.     

Conversations of objects

An increasing range of application systems implemented in concurrent object oriented languages (COOLs) creates a pressing demand for developing approaches which provide a systematic way of tolerating software and hardware faults by using software diversity. This paper deals with the problem of tolerating faults in concurrent systems of this type. The purposes of this paper are as follows: to discuss the most appropriate ways of implementing conversations in COOLs; to map all attributes of conversations onto these languages; to discuss the most relevant peculiarities of COOLs in these terms; to suggest approaches to using the conversation scheme; to find the ways in which characteristics of COOLs can facilitate the use of conversation schemes. Thus we try to show how conversations can be used in existing COOLs in a more practical and realistic manner.     

Conversations of objects

An increasing range of application systems implemented in concurrent object oriented languages (COOLs) creates a pressing demand for developing approaches which provide a systematic way of tolerating software and hardware faults by using software diversity. This paper deals with the problem of tolerating faults in concurrent systems of this type. The purposes of this paper are as follows: to discuss the most appropriate ways of implementing conversations in COOLs; to map all attributes of conversations onto these languages; to discuss the most relevant peculiarities of COOLs in these terms; to suggest approaches to using the conversation scheme; to find the ways in which characteristics of COOLs can facilitate the use of conversation schemes. Thus we try to show how conversations can be used in existing COOLs in a more practical and realistic manner.     

Cyclic twill-woven objects

Classical (or biaxial) twill is a textile weave in which the weft threads pass over and under two or more warp threads, with an offset between adjacent weft threads to give an appearance of diagonal lines. This paper introduces a theoretical framework for constructing twill-woven objects, i.e., cyclic twill-weavings on arbitrary surfaces, and it provides methods to convert polygonal meshes into twill-woven objects. It also develops a general technique to obtain exact triaxial-woven objects from an arbitrary polygonal mesh surface.     

Recovering distributed objects

Distributed multithreaded applications operating in shared-nothing environments present challenges to classical fault tolerance mechanisms. The piecewise determinism assumption is lost (due to multithreading), and data must be replicated (because of the shared-nothing environment). In this paper, we explore a systematic approach to providing fault tolerance, by considering data-race-free programs that have the benefits of piecewise determinism and yet allow multithreading. We base our logging and recovery algorithm on a logical ring structure that allows the underlying distributed system to migrate threads, migrate and replicate objects, and perform multi-object transactions.     

Bending polyhedral objects

A geometric algorithm for performing bending operations on polyhedral objects is described. The hypotheses, conditions and model of the bending process are defined, and then the mathematical model of bending is developed for each element of the boundary representation of a polyhedron. The algorithm has applications as a new means of generating geometric models and, in the CAD/CAM field, for simulating bending processes used to manufacture parts. The algorithm has been implemented and examples are given of objects transformed by the bending operation.     

Dynamic superimposition of synthetic objects on rigid and simple-deformable real objects

A current challenge in augmented reality applications is the accurate superimposition of synthetic objects on real objects within the environment. This challenge is heightened when the real objects are in motion and/or are non-rigid. In this article, we present a robust method for real-time, optical superimposition of synthetic objects on dynamic, rigid and simple-deformable real objects. Moreover, we illustrate this general method with the VRDA Tool, a medical education application enabling the visualization of internal human knee joint anatomy on a real human knee.     

Total objects of domains

The main result of this paper is a characterization of the space induced by Scott topology on the set of total objects of a bounded-complete cpo. This characterization is simple with bounded-complete algebraic cpo's where a family of clopen sets plays an essential role in the characterization. In the more general case of continuity, one can only produce distinct families of open sets and closed sets to axiomatize the essential properties of a total space. Besides the main characterization, we also discuss its relation to continuous spaces, studied in our earlier paper, and the relation between compact T spaces and total spaces under the lower topology.     

Illumination of image-based objects

A new data representation of image-based objects is presented. With this representation, the user can change the illumination as well as the viewpoint of an image-based scene. Physically correct imagery can be generated without knowing any geometrical information (e.g. depth or surface normal) of the scene. By treating each pixel on the image plane as a surface element, we can measure its apparent BRDF (bidirectional reflectance distribution function) by collecting information in the sampled images. These BRDFs allow us to calculate the correct pixel colour under a new illumination set-up by fitting the intensity, direction and number of the light sources. We demonstrate that the proposed representation allows re-rendering of the scene illuminated by different types of light sources. Moreover, two compression schemes, spherical harmonics and discrete cosine transform, are proposed to compress the huge amount of tabular BRDF data. © 1998 John Wiley & Sons, Ltd.     

On multiple moving objects

This paper explores the motion-planning problem for multiple moving objects. The approach taken consists of assigning priorities to the objects, then planning motions one object at a time. For each moving object, the planner constructs a configuration space-time that represents the time-varying constraints imposed on the moving object by the other moving and stationary objects. The planner represents this space-time approximately, using two-dimensional slices. The space-time is then searched for a collision-free path. The paper demonstrates this approach in two domains. One domain consists of translating planar objects; the other domain consists of two-link planar articulated arms.     

Infons as mathematical objects

I argue that the role played by infons in the kind of mathematical theory of information being developed by several workers affiliated to CSLI is analogous to that of the various number systems in mathematics. In particular, I present a mathematical construction of infons in terms of representations and informational equivalences between them. The main theme of the paper arose from an electronic mail exchange with Pat Hayes of Xeroxparc. The exposition derives from a talk I gave at theTheories of Partial Information conference held at the University of Texas at Austin, January 1990.     

On multiple moving objects

This paper explores the motion-planning problem for multiple moving objects. The approach taken consists of assigning priorities to the objects, then planning motions one object at a time. For each moving object, the planner constructs a configuration space-time that represents the time-varying constraints imposed on the moving object by the other moving and stationary objects. The planner represents this space-time approximately, using two-dimensional slices. The space-time is then searched for a collision-free path. The paper demonstrates this approach in two domains. One domain consists of translating planar objects; the other domain consists of two-link planar articulated arms.This report describes research performed at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Michael Erdmann is supported in part by a fellowship from General Motors Research Laboratories. Tomás Lozano-Pérez is supported by an NSF Presidential Young Investigator grant. Support for the Laboratory's Artificial Intelligence research is provided in part by the System Development Foundation, in part by the Office of Naval Research under Office of Naval Research Contract N00014-81-K-0494, and in part by the Advanced Research Projects Agency under Office of Naval Research Contracts N00014-80-C-0505 and N00014-82-K-0344.