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Abstract: This paper presents a method that integrates deterministic approach with fault-tree analysis for reliability assessment of a composite system (generation and transmission in power systems). The contingency screening is conducted in the first step. The results are further classified into three clusters in the second step: normal, local trouble and system trouble. The fault-tree analysis is used to assess the reliability of the composite system in the third step. Finally, Risk Reduction Worth is adopted as a measure of importance for identifying the crucial element that has significant impact on the reliability. In this paper, a composite system in Taiwan serves as an example for illustrating the simulation results attained by the proposed method. The simulation results, verified by Siemens PTI PSS/E TPLAN software package, show that the proposed method is applicable for large scale power systems. [Copyright &y& Elsevier]

Abstract: This paper is aimed at creating an empirical model for assessing failure potential of highway slopes, with a special attention to the failure characteristics of the highway slopes in the Alishan, Taiwan area prior to, and post, the 1999 Chi-Chi, Taiwan earthquake. The basis of the study is a large database of 955 slope records from four highways in the Alishan area. Artificial neural network (ANN) is utilized to “learn” from this database. The developed ANN model is then used to study the effect of the Chi-Chi earthquake on the slope failure characteristics in the Alishan area. Significant changes in the degrees of influence of several factors (variables) are found and possible reasons for such changes are discussed. The novelty of this paper lies in the fact that the developed ANN models are used as a tool to investigate the slope failure characteristics before and after the Chi-Chi earthquake. [Copyright &y& Elsevier]

Abstract: This paper discusses submarine morphology as a means of understanding the avulsion of the Fangliao canyon. Multichannel seismic profiles and bathymetric data were used to perform a morphological analysis. In response to tectonic uplifting, the Fangliao canyon was divided into two separate segments and two distinct trends. Initially, in the shelf edge–upper slope region the canyon extends downslope in a N–S direction. Then the canyon course bends to the SW at a depth of about 630m because of a mud diapir uplift and then returns to and maintains a N–S course with the canyon mouth at a depth of 900m, which is its present-day course. The Fangliao ridge, a mud diapiric ridge, lies east of the lower Fangliao canyon and extends upslope into the upper Fangliao canyon with a generally straight course and a nearly N–S trend. Because of the uplift of the Fangliao ridge a major step of the convex-upward profile, ~150m above the canyon floor, resulted in the east Fangliao ridge canyon. The gravity flows are unable to rise up against the high gradient and, thus, have had to abandon the segment of paleocanyon once flowing along the trend of the Fangliao ridge. The internal seismic characteristics of the terraces located along the eastern wall of the Fangliao canyon suggest deposition of terrace mainly occurs in the inner bend of the Fangliao canyon. The sedimentary sequences of the terrace are divided into two units: (1) the lower sedimentary unit is characterized by oblique, high-amplitude reflections and is considered as coarse-grained canyon fills resulting from aggradation related to the canyon avulsion events; and (2) the upper sedimentary unit consists mainly of low-amplitude reflections that are interpreted as inner levee resulting from spillover deposition. Numerical simulations were performed to discuss avulsion of the Fangliao canyon. Initially, the course of the Fangliao canyon had a N–S trend and followed the regional slope (i.e., the direction gravity currents would flow). Subsequently, the mud diapir uplifted the segment of the paleocanyon of the Fangliao canyon once flowing along the present-day Fangliao ridge and diverted its course to the present-day Fangliao canyon. The model suggests that the uplift rate exceeds the erosion rate in the east Fangliao ridge canyon, and hence the sediment flows in the canyon may be unable to pass through the 150-m major step. This new model suggests that the avulsion of the Fangliao canyon is marked by a significant bend at the boundary between the upper and lower canyons. [Copyright &y& Elsevier]

Abstract: This paper presents an approach which combines the orthogonal array experiment technique and an ant direction hybrid differential evolution algorithm (ADHDEOA) in determining the tilt angle for photovoltaic (PV) modules. In this study, an orthogonal array (OA) is first conducted to obtain the initial solution. Next, an ant direction hybrid differential evolution (ADHDE) is applied to search for a near optimum solution. The purpose of this research is to maximize the output power of the module. The sun’s position at any time and location was predicted by the mathematical procedure of Julian dating; then, the solar irradiation was obtained at each site under a clear sky. The searching for global optimal solution is applied to a practical experimental system. The results show that the annual optimal angle for the Taipei area is 23.18°; for Taichung, 22.32°; for Tainan, 21.62°; for Kaosiung, 20.83°; for Hengchung, 20.27°; for Hualian, 22.18°; and for Taitung, 20.89° in seven Taiwanese areas, and the actual best annual tilt angles are close to the computer simulation results. [Copyright &y& Elsevier]

Abstract: Additional fire barriers of electrical cables are required for the nuclear power plants (NPPs) in Taiwan due to the separation requirements of Appendix R to 10 CFR Part 50. The risk-informed fire analysis (RIFA) may provide a viable method to resolve these fire barrier issues. However, it is necessary to perform the fire scenario analyses so that RIFA can quantitatively determine the risk related to the fire barrier wrap. The CFD fire models are then proposed in this paper to help the RIFA in resolving these issues. Three typical fire scenarios are selected to assess the present CFD models. Compared with the experimental data and other model’s simulations, the present calculated results show reasonable agreements, rendering that present CFD fire models can provide the quantitative information for RIFA analyses to release the cable wrap requirements for NPPs. [Copyright &y& Elsevier]