9941221
Debugging object-oriented programs with behavior views
A complex software system may perform many program tasks during execution to provide the required functionalities. To detect and localize bugs related to the implementation of these tasks, the software developers must be able to monitor the progress of the tasks during execution and check whether the actions for these tasks have been performed correctly. This paper presents a debugger to facilitate this monitoring. The debugger introduces a new kind of abstraction, the behavior views, that can be used to specify how the actions for a program task are expected to occur in various scenarios. Enhanced with statements that can check properties at various steps during the progress of the task, a behavior view can be used to monitor whether the actions for the tasks have been performed at the right time, on the right set of data, and with the right effects on the program states. Our initial case study indicates that the debugger can be useful for localizing bugs.
13074071
Testing Scenario Implementation with Behavior Contracts
This paper presents behavior contracts as a new assertion mechanism and a tool that uses such contracts to support the testing of object-oriented (OO) systems. A behavior contract models how the scenarios for performing a designated task are expected to be implemented. Based on this contract, our tool can automatically monitor the program execution for checking important properties related to these scenarios. This capability can help testers to determine whether the scenarios have been implemented correctly. Our tool can also collect test coverage information w.r.t. the scenarios modeled by a behavior contract. Such information can be used to direct the testing efforts towards the less-covered scenarios, and to determine whether the implementation of these scenarios has been adequately tested. Therefore, using this tool should improve both the efficiency and effectiveness of testing OO systems
14395125
Monitoring with behavior view diagrams for debugging
UML sequence diagrams are widely used during requirements analysis and design for specifying the expected message exchanges among a set of objects in various scenarios for the program to perform a certain task. In this paper, we present the behavior view diagrams, a type of extended sequence diagrams, to facilitate execution monitoring during debugging. Using a behavior view diagram, software developers can precisely specify the runtime objects whose behaviors will be monitored during debugging. Software developers can also specify the important message exchanges to be observed among these objects during the progress of various scenarios, and may further define the monitoring actions to be performed for inspecting the program state when a message exchange is observed. We also present a debugger that can automatically monitor the program execution using the information specified in a behavior view diagram. Through this monitoring, the debugger can not only check whether the scenarios are progressed as intended, but also check whether the actions performed by the program have the the desired effects on the program states. Therefore, it will be useful for detecting and localizing bugs.
17014715
Test-Driven Component Integration with UML 2.0 Testing and Monitoring Profile
Test-driven development (TDD) is a software development methodology for achieving high reliability. However, the practice of TDD at the integration level is rare. In this paper, we propose a test-driven component integration approach with the support of UML 2.0 Testing and Monitoring Profile (U2TMP) that is also proposed in this paper. In our approach, automated integration-level test cases are specified using U2TMP before writing the glue-code that integrates components. U2TMP enhances UML 2.0 diagrams for specifying how test scenarios should be set up and how the integrated components are expected to interact under these scenarios. Test cases written in U2TMP can be automatically transformed into test artifacts that setup the test environment, generate test stimuli, and monitor the component interactions at runtime. These test cases serve as a guideline for writing the glue-code and a regression test- bed. With this approach, the software developers may produce glue-code of high reliability.
7264645
A Multiresolution Terrain Model for Efficient Visualization Query Processing
Multiresolution triangular mesh (MTM) models are widely used to improve the performance of large terrain visualization by replacing the original model with a simplified one. MTM models, which consist of both original and simplified data, are commonly stored in spatial database systems due to their size. The relatively slow access speed of disks makes data retrieval the bottleneck of such terrain visualization systems. Existing spatial access methods proposed to address this problem rely on main-memory MTM models, which leads to significant overhead during query processing. In this paper, we approach the problem from a new perspective and propose a novel MTM called direct mesh that is designed specifically for secondary storage. It supports available indexing methods natively and requires no modification to MTM structure. Experiment results, which are based on two real-world data sets, show an average performance improvement of 5-10 times over the existing methods
11328445
Gene Specific Co-regulation Discovery: An Improved Approach
Discovering gene co-regulatory relationships is a new but important research problem in DNA microarray data analysis. The problem of gene specific co-regulation discovery is to, for a particular gene of interest, called the target gene , identify its strongly co-regulated genes and the condition subsets where such strong gene co-regulations are observed. The study on this problem can contribute to a better understanding and characterization of the target gene. The existing method, using the genetic algorithm (GA), is slow due to its expensive fitness evaluation and long individual representation. In this paper, we propose an improved method for finding gene specific co-regulations. Compared with the current method, our method features a notably improved efficiency. We employ k NN Search Table to substantially speed up fitness evaluation in the GA. We also propose a more compact representation scheme for encoding individuals in the GA, which contributes to faster crossover and mutation operations. Experimental results with a real-life gene microarray data set demonstrate the improved efficiency of our technique compared with the current method.
815255
Detecting Projected Outliers in High-Dimensional Data Streams
In this paper, we study the problem of projected outlier detection in high dimensional data streams and propose a new technique, called Stream Projected Ouliter deTector (SPOT), to identify outliers embedded in subspaces. Sparse Subspace Template (SST), a set of subspaces obtained by unsupervised and/or supervised learning processes, is constructed in SPOT to detect projected outliers effectively. Multi-Objective Genetic Algorithm (MOGA) is employed as an effective search method for finding outlying subspaces from training data to construct SST. SST is able to carry out online self-evolution in the detection stage to cope with dynamics of data streams. The experimental results demonstrate the efficiency and effectiveness of SPOT in detecting outliers in high-dimensional data streams.
1243612
Feature-aligned shape texturing
The essence of a 3D shape can often be well captured by its salient feature curves. In this paper, we explore the use of salient curves in synthesizing intuitive, shape-revealing textures on surfaces. Our texture synthesis is guided by two principles: matching the direction of the texture patterns to those of the salient curves, and aligning the prominent feature lines in the texture to the salient curves exactly. We have observed that textures synthesized by these principles not only fit naturally to the surface geometry, but also visually reveal, even reinforce, the shape's essential characteristics. We call these feature-aligned shape texturing. Our technique is fully automatic, and introduces two novel technical components in vector-field-guided texture synthesis: an algorithm that orients the salient curves on a surface for constrained vector field generation, and a feature-to-feature texture optimization.
795323
Multiresolution Spatial Databases: Making Web-Based Spatial Applications Faster
Spatial data has now been used extensively in the Web environment, providing online customized maps and supporting map-based applications. The full potential of Web-based spatial applications, however, has yet to be achieved due to performance issues related to the large sizes and high complexity of spatial data. In this paper, we introduce a multiresolution approach to spatial data management and query processing such that the database server can choose spatial data at the right resolution level for different Web applications. One highly desirable property of the proposed approach is that the server-side processing cost and network traffic can be reduced when the level of resolution required by applications are low. Another advantage is that our approach pushes complex multiresolution structures and algorithms into the spatial database engine. That is, the developer of spatial Web applications needs not to be concerned with such complexity. This paper explains the basic idea, technical feasibility and applications of multiresolution spatial databases.