This paper deals with the economically optimized design and sensitivity of two of the most widely used systems in geotechnical engineering: spread footing and retaining wall. Several recent advanced optimization methods have been developed, but very few of these methods have been applied to geotechnical problems. The current research develops a modified particle swarm optimization (MPSO) approach to obtain the optimum design of spread footing and retaining wall. The algorithm handles the problem-specific constraints using a penalty function approach. The optimization procedure controls all geotechnical and structural design constraints while reducing the overall cost of the structures. To verify the effectiveness and robustness of the proposed algorithm, three case studies of spread footing and retaining wall are illustrated. Comparison of the results of the present method, standard PSO, and other selected methods employed in previous studies shows the reliability and accuracy of the algorithm. Moreover, the parametric performance is investigated in order to examine the effect of relevant variables on the optimum design of the footing and the retaining structure utilizing the proposed method.

The thermal performance enhancement of the hydronic radiant floor heating system by tube shape refinements is investigated in this paper. Both analytical and detailed numerical modelings are carried out to predict the performance of the radiant system. While the simple analytical model briefly investigates the possibility of the effect of the tube shape improvement with the parametric analysis, the commercial computational fluid dynamics (CFD) code (Ansys/CFX) is used to perform the detailed 3D analysis under different tube shape conditions. The fin thickness, the number of fins, and the tube thermal conductivity turn out to have significant effects on the radiant system performance. The potential energy saving impacts of the tube shape refinements are also discussed. The tube shape improvement turns out to increase the floor surface temperature and to decrease the hot water temperature drop across the system, resulting in heating energy savings.

The photoplethysmogram (PPG) of a pulse wave, similar in appearance to the arterial blood pressure (ABP) waveform, contains rich information about the cardiovascular system. The decay time constant RC, equal to the product of peripheral resistance R and total arterial compliance C, is a meaningful cardiovascular model parameter in vascular assessment. Using or ameliorating the existing ABP methods does not achieve a satisfactory estimation of RC from the PPG volume pulse (VRC). Thus, a novel non-iterative shape method (NSM) of evaluating VRC is introduced in this paper. The mathematic expression between a novel, readily available morphological parameter called the area difference ratio (ADR) and VRC was established. As it was difficult to calculate VRC from the complicated expression analytically, we recommend estimating it using a piecewise linear interpolation criterion. Also, since the effect of the PPG magnitude is eliminated in the calculation of ADR, precaliberation or normalization is dispensable in the NSM. Results of human experiments indicated that the NSM was computationally efficient, and the simulation experiments confirmed that the NSM was theoretically available for ABP.

A model-based estimator design and implementation is described in this paper to undertake combined estimation of vehicle states and tire-road friction coefficients. The estimator is designed based on a vehicle model with three degrees of freedom (3-DOF) and the dual extended Kalman filter (DEKF) technique is employed. Effectiveness of the estimation is examined and validated by comparing the outputs of the estimator with the responses of the vehicle model in CarSim in three typical road adhesion conditions (high-friction, low-friction, and joint-friction roads). Simulation results demonstrate that the DEKF estimator algorithm designed is able to obtain vehicle states (e.g., yaw rate and roll angle) as well as road friction coefficients with reasonable accuracy.

This paper introduces a new enhancement method for multi-spectral satellite remote sensing imagery, based on principal component analysis (PCA) and intensity-hue-saturation (IHS) transformations. The PCA and the IHS transformations are used to separate the spatial information of the multi-spectral image into the first principal component and the intensity component, respectively. The enhanced image is obtained by replacing the intensity component of the IHS transformation with the first principal component of the PCA transformation, and undertaking the inverse IHS transformation. The objective of the proposed method is to make greater use of the spatial and spectral information contained in the original multi-spectral image. On the basis of the visual and statistical analysis results of the experimental study, we can conclude that the proposed method is an ideal new way for multi-spectral image quality enhancement with little color distortion. It has potential advantages in image mapping optimization, object recognition, and weak information sharpening.

Six transition metal oxides were added in ceria-modified titania using a sol-gel method for catalytic oxidation of toluene. An MnOx based catalyst was found to be the most active one, with which toluene could be decomposed completely at 200 ºC. The greatest Mn/Ti and molar ratio of the mobile oxygen to the total oxygen concentration, together with a large surface area and a low reduction peak-starting temperature, would result in its best activity in toluene oxidation.

The charging characteristics of the valve-regulated lead acid (VRLA) battery driven by solar energy were experimentally studied through the pressure-control method in this paper. The aims of the research were to increase charging efficiency to make the most of solar energy and to improve charging quality to prolong life of battery. The charging process of a 12 V 12 A·h VRLA battery has been tested under the mode of a stand-alone photovoltaic (PV) system. Results show that the pressure-control method can effectively control PV charging of the VRLA battery and make the best of PV cells through the maximum power point tracking (MPPT). The damage of VRLA battery by excess oxygen accumulation can be avoided through the inner pressure control of VRLA battery. Parameters such as solar radiation intensity, charging power, inner pressure of the battery, and charging current and voltage during the charging process were measured and analyzed.

In this paper, a 60 kW proton exchange membrane fuel cell (PEMFC) generation system is modeled in order to design the system parameters and investigate the static and dynamic characteristics for control purposes. To achieve an overall system model, the system is divided into five modules: the PEMFC stack (anode and cathode flows, membrane hydration, and stack voltage and power), cathode air supply (air compressor, supply manifold, cooler, and humidifier), anode fuel supply (hydrogen valve and humidifier), cathode exhaust exit (exit manifold and water return), and power conditioning (DC/DC and DC/AC) modules. Using a combination of empirical and physical modeling techniques, the model is developed to set the operation conditions of current, temperature, and cathode and anode gas flows and pressures, which have major impacts on system performance. The current model is based on a 60 kW PEMFC power plant designed for residential applications and takes account of the electrochemical and thermal aspects of chemical reactions within the stack as well as flows of reactants across the system. The simulation tests show that the system model can represent the static and dynamic characteristics of a 60 kW PEMFC generation system, which is mathematically simple for system parameters and control designs.

Regional drought analysis provides useful information for sustainable water resources management. In this paper, a standardized precipitation index (SPI) at multiple time scales was used to investigate the spatial patterns and trends of drought in the Han River Basin, one of the largest tributaries of Yangtze River, China. It was found that, in terms of drought severity, the upper basin of the Han River is the least, while the growing trend is the most conspicuous; a less conspicuous growing trend can be observed in the middle basin; and there is an insignificant decreasing trend in the lower basin. Meanwhile, the impact of drought on the Middle Route of the South-to-North Water Transfer Project was investigated, and it is suggested that water intake must be reduced in times of drought, particularly when successive or simultaneous droughts in the upper and middle basins of the Han River Basin occur. The results can provide substantial information for future water allocation schemes of the South-to-North Water Transfer Project.