The Optimal Spatially-Smoothed Source Patterns for the Pseudospectral Time-Domain Method

Spatially-smoothed sources are often utilized in the pseudospectral time-domain (PSTD) method to suppress the associated aliasing errors to levels as low as possible. In this work, the explicit conditions of the optimal source patterns for these spanning sources are presented based on the fact that the aliasing errors are mainly attributed to the high spatial-frequency parts of the time-stepped source items and subsequently demonstrated to be exactly corresponding to the normalized rows of Pascal's triangle. The outstanding performance of these optimal sources is verified by the practical 1-D, 2-D and 3-D PSTD simulations and compared with that of non-optimal sources.Comment: 4 page

The Response of Pile-Guided Floats Subjected to Dynamic Loading

INE/AUTC 14.10 (Volume 1) and INE/AUTC 14.10b (Volume II Annex

Response of pile-guided floats subjected to dynamic loading

Pile-guided floats can be a desirable alternative to stationary berthing structures. Both floats and guide piles are subjected to time varying (dynamic) forces such as wind-generated waves and impacts from vessels. There is little design information available concerning the dynamic load environment to which the floats will be subjected. So far, the most widely acceptable method used in offshore structure design is the Kinetic Energy Method (KEM). It is a simplified method that is based on the conservation of energy. This approach is straightforward and easy to implement. However, in spite of its simplicity and straightforwardness, the method lacks accuracy. The intent of this project is to develop a rational basis for estimating the dynamic response of floating pile-guided structures, providing necessary insight into design requirements of the guide-piles. In this study, the Dynamic Analysis Method (DAM) will be used to model the dynamic responses of the system. MATLAB codes are written to help calculate the analytic and numerical values obtained from the dynamic models. For the purpose of validation, results from the two systems should be compared to a comprehensive dynamic analysis model created with the ANSYS AQWA Software

Rule Responder: A Rule-Based Semantic eScience Service Infrastructure

To a large degree information and services for chemical e-Science have become accessible -anytime, anywhere -but not necessarily useful. The Rule Responder eScience middleware is about providing information consumers with rule-based agents to transform existing information into relevant information of practical consequences, hence providing control to the end-users to express in a declarative rule-based way how to turn existing information into personally relevant information and how to react or make automated decisions on top of it

PS-TRUST: Provably Secure Solution for Truthful Double Spectrum Auctions

Truthful spectrum auctions have been extensively studied in recent years. Truthfulness makes bidders bid their true valuations, simplifying greatly the analysis of auctions. However, revealing one's true valuation causes severe privacy disclosure to the auctioneer and other bidders. To make things worse, previous work on secure spectrum auctions does not provide adequate security. In this paper, based on TRUST, we propose PS-TRUST, a provably secure solution for truthful double spectrum auctions. Besides maintaining the properties of truthfulness and special spectrum reuse of TRUST, PS-TRUST achieves provable security against semi-honest adversaries in the sense of cryptography. Specifically, PS-TRUST reveals nothing about the bids to anyone in the auction, except the auction result. To the best of our knowledge, PS-TRUST is the first provably secure solution for spectrum auctions. Furthermore, experimental results show that the computation and communication overhead of PS-TRUST is modest, and its practical applications are feasible.Comment: 9 pages, 4 figures, submitted to Infocom 201