Browsing by Author "Tsai, Chung-Hung"

Because large amount of ground water have been excessively withdrawn within the lowlands along the southwestern area in Taiwan, the land subsidence becomes a serious problem that property damages and life losses in the subsidence area will be caused by the poor drainage and serious flooding arise during the periods of typhoon and heavy rainfall. Therefore, how to monitor and analyze the land subsidence effectively will be an important study issue. In this study, many kinds of geospatial information are firstly collected and analyzed for subsidence monitoring. The error adjustment of the multi-temporal Digital Elevation Models (DEMs) data is implemented using the Least Squares Collocation (LSC) method proposed in our previous research works. Then the HEC-RAS and FLO-2D models are used to simulate the flood hazards to test the performance of the LSC adjustment method. The results are also used to analyze the influence of the land subsidence for flood hazards. © 2010 IEEE.

The World Wide Web has become a sophisticated platform capable of delivering a broad range of applications. However, its rapid growth has resulted in numerous security problems that current technologies cannot address. Researchers from both academic and private sector are devoting a considerable amount of resources to the development of Web application security scanners (i.e., automated software testing platforms for Web application security auditing) with some success. However, little is known about their potential side effects. It is possible for an auditing process to induce permanent changes in an application's state. Due to this potential, we have so far avoided large-scale empirical evaluations of our Web Application Vulnerability and Error Scanner (WAVES). In this paper we introduce a testing methodology that allows for harmless auditing, define three testing modes-heavy, relaxed, and safe modes, and report our results from two experiments. In the first, we compared the coverage and side effects of the three scanning modes using 5 real-world Web applications chosen from the 38 found vulnerable in a previous static verification effort. In the second, we used the relaxed mode to conduct a 48-hour test involving 1120 random websites, of which 55 were found to be vulnerable. © 2004 IEEE.