An iterative interacting method for dynamic analysis of the maglev train-guideway/foundation-soil system

This paper presents an iterative interacting method for analyzing the dynamic response of a maglev train traveling on an elevated guideway supported by piers embedded in soil. The maglev train is idealized as a row of 2D rigid beams each suspended by levitation forces and controlled by onboard PID controllers. The guideway is modeled as a series of simple beams supported by rigid piers embedded in an elastic half-space. To address the structure interactions from the train to the soil and vice versa, the entire model is decomposed into two subsystems, i.e., the maglev train-guideway and foundation-soil subsystems, each interacting with the other via the rigid piers. The procedure of analysis is as follows: First, the train-guideway subsystem is computed, and the support reactions are used as excitations to the elastic half space. Next, the ground vibrations induced by the pier excitations are computed and fed back via the supports for computing the train-guideway response. The procedure is repeated until the convergence condition is satisfied. The solution obtained for a 2-degree-of-freedom system under a harmonic force is compared with the analytical one to verify the validity of the method proposed herein. The effects of ground wave propagation on the vehicle-guideway response will be evaluated in the numerical examples.     

The ventilation of multiple-bed hospital wards in the tropics: A review

Hospital and healthcare facilities have diverse indoor environment due to the different comfort and health needs of its occupants. Currently, most ventilation studies revolve around specialised areas such as operating rooms and isolation rooms. This paper focuses on the ventilation of multiple-bed hospital wards in the tropical climate, taking into account the design, indoor conditions and engineering controls. General ward layouts are described briefly. The required indoor conditions such as temperature, humidity, air movements and indoor air quality in the ward spaces are summarized based on the current guidelines and practices. Also, recent studies and engineering practices in the hospital indoor environment are elaborated. Usage of computational fluid dynamics tools for the ventilation studies is discussed as well. As identified during the review, there is an apparent knowledge gap for ventilation studies in the tropics compared with temperate climates, as fact studies have only been published for hospital wards in countries with a temperate climate. Therefore, it is highlighted that specific tropical studies along with novel engineering controls are required in addressing the ventilation requirements for the tropics.     

The application of heat pipe heat exchangers to improve the air quality and reduce the energy consumption of the air conditioning system in a hospital ward—A full year model simulation

Research was conducted to study the effect of heat pipe heat exchangers on the existing air conditioning system of a hospital ward located in Malaysia, a tropical region. The present research employs the transient system simulation software (TRNSYS) to study the hour-by-hour performance of the system in terms of supply duct air and indoor air conditions in the ward space. Fieldwork study showed that the existing air conditioning system operating in the Orthopaedic Ward, University of Malaya, Malaysia is not capable of providing the desired supply duct air and indoor air to the space. Therefore, the possibility of improving the air conditioning system by adding heat pipe heat exchangers was investigated. The impact on energy consumption, power savings, supply duct air and indoor air with heat pipe heat exchangers incorporated in the air conditioning system were simulated and the results were compared with the existing system.Based on the present research, the system with the added eight-row heat pipe heat exchangers is recommended to provide convenient and healthy air into the ward space according to the ASHRAE recommendations. Moreover, it was found that by applying the new design, a considerable amount of energy and power could be saved.     

Property price gradients: the vertical dimension

This is an empirical study on the pricing of two vertical property attributes: floor level and building height. Floor level is the vertical location of a unit in a multi-storey building; the extra price paid for a higher floor level is labelled a floor-level premium. Previous hedonic price studies unequivocally showed that the floor-level premium is positive, but they were silent on whether its magnitude varies with floor levels and with buildings of different heights. Indeed, building height is a feature of a building, not its constituent units, so it is not clear whether building height alone should affect the units’ prices. Based on a sample of highly homogeneous housing units in buildings of varying heights, we found that (1) the floor-level premium was not constant, but diminished as floor level increases; (2) there was no significant difference in the pattern of the floor-level premium between high-rise and low-rise buildings; and (3) there was a positive and significant premium for units in low-rise buildings over those in high-rise ones. These findings can help developers determine the optimal height and shape of their development.     

Automated age regression for personalized IPTV services

The increasing penetration rates of high speed broadband networks have infused strong impetus for IPTV adoption and usage. One of the more intriguing possibilities of personalizing the IPTV experience is to install automated age classification capabilities onto a display set. This allows the detection, by vision-based methods, of the demographic profile of the IPTV user and automatically suggest or stream services, advertisements and adjust settings to provide a personalized IPTV experience to the user. We describe a vision-based age estimation system, capable of estimating the age of a person using the near frontal face with a mean average error of 4.64 years, using various proposed techniques such as facial alignment and hierarchical manifold-based regression. We discuss the likely scenarios where such a capability can be applied, and the likely impact it will have on the user experience. Finally, the paper explores related user issues and the possible solutions within the IPTV context.     

Computing shortest words via shortest loops on hyperbolic surfaces

Given a loop on a surface, its homotopy class can be specified as a word consisting of letters representing the homotopy group generators. One of the interesting problems is how to compute the shortest word for a given loop. This is an NP-hard problem in general. However, for a closed surface that allows a hyperbolic metric and is equipped with a canonical set of fundamental group generators, the shortest word problem can be reduced to finding the shortest loop that is homotopic to the given loop, which can be solved efficiently. In this paper, we propose an efficient algorithm to compute the shortest words for loops given on triangulated surface meshes. The design of this algorithm is inspired and guided by the work of Dehn and Birman–Series. In support of the shortest word algorithm, we also propose efficient algorithms to compute shortest paths and shortest loops under hyperbolic metrics using a novel technique, called transient embedding, to work with the universal covering space. In addition, we employ several techniques to relieve the numerical errors. Experimental results are given to demonstrate the performance in practice.     

Legal Impact and Dispute Resolution of Disaster in Taiwan: Lessons Learned from Typhoon Aere

The combination of a natural disaster and human ignorance, such as Hurricane Katrina in New Orleans, can incur enormous property damage and loss of life. In August 2004, Typhoon Aere hit Taiwan and flooded over one-third of Sanchung City, in Taipei County. The attempt by a contractor to save New Taiwan Dollar 1,000 (about United States Dollar 30) resulted in enormous loss of property and as many as 18,941 claims. This case study examines the following possibility of tort claims, criminal charges, and administrative action in Taiwan. Alternative dispute-resolution (ADR) methods and processing proposition of disasters would be other issues discussed in this paper. The catastrophe revealed how government agencies and contractors deal with victims and restore order to society. Years of research expose that an integration of various dispute-resolution methods is constructive to achieve favorable outcomes, and a stepwise approach consisting of ADR methods is effective in resolving disputes after Typhoon Aere as well.     

Matching and Fairness in Threat-Based Mobile Sensor Coverage

Mobile sensors can be used to effect complete coverage of a surveillance area for a given threat over time, thereby reducing the number of sensors necessary. The surveillance area may have a given threat profile as determined by the kind of threat, and accompanying meteorological, environmental, and human factors. In planning the movement of sensors, areas that are deemed higher threat should receive proportionately higher coverage. We propose a coverage algorithm for mobile sensors to achieve a coverage that will match—over the long term and as quantified by an RMSE metric—a given threat profile. Moreover, the algorithm has the following desirable properties: 1) stochastic, so that it is robust to contingencies and makes it hard for an adversary to anticipate the sensor's movement, 2) efficient, and 3) practical, by avoiding movement over inaccessible areas. Further to matching, we argue that a fairness measure of performance over the shorter time scale is also important. We show that the RMSE and fairness are, in general, antagonistic, and argue for the need of a combined measure of performance, which we call efficacy. We show how a pause time parameter of the coverage algorithm can be used to control the trade-off between the RMSE and fairness, and present an efficient offline algorithm to determine the optimal pause time maximizing the efficacy. Finally, we discuss the effects of multiple sensors, under both independent and coordinated operation. Extensive simulation results—under realistic coverage scenarios—are presented for performance evaluation.     

Single beam one-way imaging through a thick dynamic turbulent medium

A new method to record an image through a thick dynamic phase distorting medium by using a photorefractive LiNbO3 crystal is demonstrated. The method uses only one beam of light, the object light. By making use of the photorefractive fanning effect, gratings are formed in the LiNbO3 crystal through the interference between the object light and its own fanning light. Because the time scale of the distorting fluctuation is much shorter than the writing time of the LiNbO3 crystal, the fluctuated light does not induce any fanning. Therefore only the static portion of the image is recorded in the crystal, and the intensity distribution of the image can then be reconstructed at any later time.