Sensitivity analysis and optimization of vehicle–bridge systems based on combined PEM–PIM strategy

This paper presents a new optimization method for coupled vehicle–bridge systems subjected to uneven road surface excitation. The vehicle system is simplified as a multiple rigid-body model and the single-span bridge is modeled as a simply supported Bernoulli–Euler beam. The pseudo-excitation method transforms the random surface roughness into the superposition of a series of deterministic pseudo-harmonic excitations, which enables convenient and accurate computation of first and second order sensitivity information. The precise integration method is used to compute the vertical random vibrations for both the vehicle and the bridge. The sensitivities are used to find the optimal solution, with vehicle ride comfort taken as the objective function. Optimization efficiency and computational accuracy are demonstrated numerically.     

Solvability conditions and solutions to perfect regulation problem under measurement output feedback

The problem of perfect regulation is to design a family of control laws for a given plant such that the resulting overall closed-loop system is internally stable and its controlled output can be reduced to zero arbitrarily fast from any initial condition. Such a problem was heavily studied by many researchers in the 1970s and early 1980s. However, to the best of our knowledge, all of the earlier results deal only with the problem under full state feedback. In this paper, we solve the long-standing problem of perfect regulation via measurement output feedback for general linear time-invariant multivariable systems. In particular, we derive necessary and sufficient conditions under which the problem of perfect regulation via measurement output feedback is solvable for general systems, and, under these conditions, construct two families of feedback laws, one of full order and the other reduced order, that solve the problem.     

A Special Session on Granular Computing and Interval Computations at the 19th International Conference of the North American Fuzzy Information Processing Society (NAFIPS) Atlanta,Georgia, July 13–15, 2000

Reliable Computing -     

信息系统工程监理简述

信息系统工程监理对大多数人来说还很陌生,目前国内甚至还没有一套完善的信息化建设项目的监理制度。但对信息化建设项目实施监理,毕竟是大势所趋,尤其是这一市场需求的大量存在,将极大地促进信息化建设项目监理市场的成熟。     

A MEMS Thermal Biosensor for Metabolic Monitoring Applications

This paper presents a microelectromechanical systems (MEMS) differential thermal biosensor integrated with microfluidics for metabolite measurements in either flow-injection or flow-through mode. The MEMS device consists of two identical freestanding polymer diaphragms, resistive heaters, and a thermopile between the diaphragms. Integrated with polymer-based microfluidic measurement chambers, the device allows sensitive measurement of small volumes of liquid samples. Enzymes specific to a metabolic analyte system are immobilized on microbeads packed in the chambers. When a sample solution containing the analyte is introduced to the device, the heat released from the enzymatic reactions of the analyte is detected by the thermopile. The device has been tested with glucose solutions at physiologically relevant concentrations. In flow-injection mode, the device demonstrates a sensitivity of approximately 2.1 muV/mM and a resolution of about 0.025 mM. In flow-through mode with a perfusion flow rate of 0.5 mL/h, the sensitivity and resolution of the device are determined to be approximately 0.24 muV/mM and 0.4 mM, respectively. These results illustrate that the device, when integrated with subcutaneous sampling methods, can potentially allow for continuous monitoring of glucose and other metabolites.     

Comparison between on- and off-campus behaviour and adaptability in online learning: a case from China

More and more universities and colleges are providing online courses not only for on-campus students but also for off-campus students. Tutors have to consider the differences between on- and off-campus students in order to improve effective instruction. Comparisons are made in this paper between on- and off-campus performances in online learning from four areas: learning time, path of browsing courseware, intercommunication and adaptability towards online learning. The last two areas are emphasized. Multiple approaches were adopted to collect data, which include questionnaires, posted documents, online logs, interviews and observations. This study shows that the rush time of online learning, paths of browsing courseware and favourite intercommunication means of on- and off-campus students are similar. But there are also some differences between these two groups such as competence of self-learning, enthusiasm of interpersonal exchange, dependence on tutors, feeling of learning stress, etc.     

水和甲醇存在下MAMS的消失反应动力学研究

通过实验研究了甲基丙烯酰胺硫酸盐（ＭＡＭＳ）与甲醇、水进行反应的动力学，并对该反应的机理进行了探讨。     

Effect of pre-existing substructures on the fatigue properties of pure aluminium

Pure aluminium was thermomechanically treated (cold rolled to 80% reduction of thickness and annealed at 200° C for various lengths of time) in order to obtain different kinds of substructures. These aluminium specimens were then fatigued with a stress amplitude of 9×10³ psi or 90% of their ultimate tensile strength. The substructures of the specimens before and after fatigue were compared with each other and were then correlated to their fatigue property. The size and shape of substructure introduced by fatigue depend on the pre-existing substructure formed by thermomechanical treatment. The sub-boundaries of the fatigued specimen are not as well-defined as the pre-existing subgrain. The substructure size of the fatigued specimen increases initially with annealing time and then reaches a saturation value (2.32 m) when the annealing time is longer than 2 h. A peak value of fatigue life against the annealing time was found if the stress amplitude of fatigue is 90% of the ultimate tensile strength. The peak value also occurs at an annealing time of 2 h. The reason why the specimen annealed for 2 h possesses the optimum fatigue and property is discussed in terms of the substructures before and after fatigue.     

Facial expression recognition using radial encoding of local Gabor features and classifier synthesis

Primarily motivated by some characteristics of the human visual cortex (HVC), we propose a new facial expression recognition scheme, involving a statistical synthesis of hierarchical classifiers. In this scheme, the input images of the database are first subjected to local, multi-scale Gabor-filter operations, and then the resulting Gabor decompositions are encoded using radial grids, imitating the topographical map-structure of the HVC. The codes are fed to local classifiers to produce global features, representing facial expressions. Experimental results show that such a hybrid combination of the HVC structure with a hierarchical classifier significantly improves expression recognition accuracy when applied to wide-ranging databases in comparison with the results in the literature. Furthermore, the proposed system is not only robust to corrupted data and missing information, but can also be generalized to cross-database expression recognition.