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Journal of Marine Science and Technology–Taiwan

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Full-Text Articles in Engineering

Case Study Of Wind-Resistant Design And Analysis Of High Mast Structures Based On Different Wind Codes, Ching-Wen Chien, Jing-Jong Jang Dec 2008

Case Study Of Wind-Resistant Design And Analysis Of High Mast Structures Based On Different Wind Codes, Ching-Wen Chien, Jing-Jong Jang

Journal of Marine Science and Technology–Taiwan

The high mast structure (HMS) has the characters of light weight and high cost efficiency. Therefore, it is widely used in the modern construction industry. It has a large the ratio of height (H) to least horizontal dimension (D) that makes it a particularly more slender and wind-sensitive than any other structures. Therefore, the purpose of this research is to develop the wind-resistant design (WRD) procedure for the slender, tapered support structures of HMS subjected to wind-induced excitation from vortex shedding and gust buffeting. This paper illustrates the theoretical basis and the analytical development of the WRD; including calculating gust …

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Variable-Thickness Boundary Layers For Sliding Mode Control, Chyun-Chau Fuh Dec 2008

Variable-Thickness Boundary Layers For Sliding Mode Control, Chyun-Chau Fuh

Journal of Marine Science and Technology–Taiwan

Sliding mode control is a nonlinear feedback control technique which provides good robustness against modeling uncertainties and external disturbances. However, as the uncertainties or disturbances increase, a greater control input is required, and the control signal may cause an undesirable chattering phenomenon. In general, the further the system trajectory from the origin, the more violent the chattering effect. However, as the trajectory moves closer to the origin, the degree of chattering gradually reduces. As a result, even if an attempt is made to eliminate chattering by introducing a small constant boundary layer around the sliding surface, the chattering phenomenon may …

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Discrete-Time Output Feedback Sliding Mode Control For Uncertain Systems, Ming-Chang Pai Dec 2008

Discrete-Time Output Feedback Sliding Mode Control For Uncertain Systems, Ming-Chang Pai

Journal of Marine Science and Technology–Taiwan

This paper presents a discrete-time output feedback sliding mode control to stabilize a class of linear uncertain systems in which the state is unavailable and no estimated state is required. The proposed sliding mode controller is derived to guarantee the existence of quasi-sliding mode by using output feedback only and the stability of overall closed-loop system is assured. This scheme ensures the robustness against parametric uncertainties and disturbances. Neither chattering phenomenon will occur nor the knowledge of upper bound of uncertainties is required. Simulation results demonstrate the efficacy of the proposed control methodology.

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The Manpower Supply Planning And Shift Setting For Mass Rapid Transit Carriage Maintenance In Short-Term Operations, Shangyao Yan, Chia-Hung Chen, Miawjane Chen Dec 2008

The Manpower Supply Planning And Shift Setting For Mass Rapid Transit Carriage Maintenance In Short-Term Operations, Shangyao Yan, Chia-Hung Chen, Miawjane Chen

Journal of Marine Science and Technology–Taiwan

An effective carriage maintenance plan cannot only reduce the mass rapid transit system operating costs, but is also directly related to its safety and schedule punctuality. Traditionally, the arrangement of the carriage maintenance manpower supply has been based on staff experience, and has been performed manually following simple rules. This is not only time-consuming but often ineffective. Therefore, in this research, we incorporate flexible management strategies, different combinations of principles, and the related operating constraints, to develop a basic carriage maintenance manpower supply plan model. Furthermore, we construct an integrated model by modifying the basic model, which can help an …

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Determining The Repair Ranking Of Existing Rc Bridges Using Multi-Pole Fuzzy Pattern Recognition Evaluation Method, Ming-Te Liang, Ting- Bang Chu, Wen-Hu Tsao, Chi-Jang Yeh Sep 2008

Determining The Repair Ranking Of Existing Rc Bridges Using Multi-Pole Fuzzy Pattern Recognition Evaluation Method, Ming-Te Liang, Ting- Bang Chu, Wen-Hu Tsao, Chi-Jang Yeh

Journal of Marine Science and Technology–Taiwan

This paper proposes a technique for determining the repair ranking of existing reinforced concrete (RC) bridges using the multi-pole fuzzy pattern recognition evaluation method. The differences between bridges and grades are expressed by weighted generalized weight distance. To find the optimal relative membership degree of an evaluated bridge attributed to any grade, the operative principle is that the sum of the square of weighted generalized weight distance is minimum. Based on this principle, the problem of extreme value is established by the objective function in connection with constraint condition. Using the Lagrangean method, the multi-pole fuzzy pattern recognition evaluation method …

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Web-Based Information Management System For The Long Term Ecological Research Program In Kenting, Taiwan, Yang-Chi Chang, Meng-Tsung Lee, Kun-Chi Lai Sep 2008

Web-Based Information Management System For The Long Term Ecological Research Program In Kenting, Taiwan, Yang-Chi Chang, Meng-Tsung Lee, Kun-Chi Lai

Journal of Marine Science and Technology–Taiwan

This paper introduces a web-based information management system which has been set up as a collaborative facility to allow key environmental and ecological information access for the Long Term Ecological Research (LTER) in Kenting, Taiwan. The coral reef ecosystem degradation in Kenting has concerned both public and private sectors, for which a LTER team was formed to investigate the problem. A multi-functional web-based system integrates diverse data collections and analyses efforts of team members during the project span. It also provides authorities with effective information and knowledge for sustainable coral reef management. Three information technologies, web Database Management System (DBMS), …

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Dynamic Reynolds Equation For Micropolar Fluid Lubrication Of Porous Slider Bearings, Neminath Bhujappa Naduvinamani, Gudadappagouda Basanagouda Marali Sep 2008

Dynamic Reynolds Equation For Micropolar Fluid Lubrication Of Porous Slider Bearings, Neminath Bhujappa Naduvinamani, Gudadappagouda Basanagouda Marali

Journal of Marine Science and Technology–Taiwan

In this paper an attempt has been made to study the rheological effects of micropolar fluid lubricants on the steady state and dynamic behavior of porous slider bearings by considering the squeezing action. The general modified Reynolds-type equation of porous sliding-squeezing surfaces with micropolar fluids is derived for the assessment of dynamic characteristics of bearings with general film thickness. The detailed analysis is presented for the plane inclined porous slider bearings by using perturbation method. Two Reynolds-type equations corresponding to steady performance and perturbed characteristics are obtained. The closed form solution of these equations is obtained. The numerical computations of …

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Developing A Convective Code With Vorticity Transport In Upwind Method, Je -Ee Ho Sep 2008

Developing A Convective Code With Vorticity Transport In Upwind Method, Je -Ee Ho

Journal of Marine Science and Technology–Taiwan

The Navier-Strokes equations are usually used to solve the convective problems, however, to satisfy the conversation of mass, the uncertainty of pressure terms will easily trigger off the numerical divergence during the iterative process; which results in a calculating failure and makes the numerical solutions impossible. In this study, a vorticity–transport method that avoids the involvement of pressure terms by cross differentiate the governing equations and meets the flow conservation with stream function was proposed. With the aid of the upwind scheme and implicit method, an effective transformation from the partial differential equations into the vortex potential algebraic equations would …

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Multi-Objective Control Design For Stochastic Large-Scale Systems Based On Lmi Approach And Sliding Mode Control Concept, Koan-Yuh Chang, Wen-Jer Chang Sep 2008

Multi-Objective Control Design For Stochastic Large-Scale Systems Based On Lmi Approach And Sliding Mode Control Concept, Koan-Yuh Chang, Wen-Jer Chang

Journal of Marine Science and Technology–Taiwan

In this paper, a controller u (t) i is designed for stochastic large-scale systems to achieve the following three objectives simultaneously: the pole placement constraint, H∞ norm constraint and individual state variance constraint. In terms of the invariance property of sliding mode control, both the uncertain interconnection terms and an unknown nonlinear function will disappear on the sliding mode. Then, with the aid of upper bound covariance control theory, pole placement skill and H∞ norm control theory, a controller, in which the control feedback gain matrix Gi is synthesized using linear matrix inequality approach, is derived to achieve the above …

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Effect Of Steel Fiber On The Mechanical Properties Of Cement-Based Composites Containing Silica Fume, Wei-Ting Lin, Ran Huang, Chin-Lai Lee, Hui-Mi Hsu Sep 2008

Effect Of Steel Fiber On The Mechanical Properties Of Cement-Based Composites Containing Silica Fume, Wei-Ting Lin, Ran Huang, Chin-Lai Lee, Hui-Mi Hsu

Journal of Marine Science and Technology–Taiwan

An experimental program was carried out to evaluate the mechanical properties of cement-based composites. Test variables included water to cementitious ratio, dosage of silica fume and volume fraction of steel fiber. Compressive strength test, direct tensile strength test, splitting tensile strength test, abrasion resistance test and drop weight test were performed and the results were analyzed statistically. According to the results of this study, the designed direct tensile testing method was a suitable method to estimate the tensile strength of fiber cement-based composites. Addition of fibers provided better performance for the cement-based composites, while silica fume in the composites would …

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Characteristic Study Of Mhd Minipump, Je -Ee Ho Sep 2008

Characteristic Study Of Mhd Minipump, Je -Ee Ho

Journal of Marine Science and Technology–Taiwan

The present study aims to develop and discuss the availability of the Magneto Hydrodynamics Minipump (MHD) as a miniaturizative part specified for precise manufacturing or medical application. Based on the MHD theory, an available working current (1.8A) induced by lower voltage (0-12V) and weaker magnetic intensity (0.04T) meets the need in mini-system operation. However, precise estimations of working capacity, maximum head, dynamic head, and static head in various electrolyte concentrations are necessary. Furthermore, this work also provides a simplified analytic model with a static balance between Lorentz force, surface tension force, and body force. Compared with analytic solutions and experimental …

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Using Factor Analysis To Assess Route Construction Priority For Common Duct Network In Taiwan, Wei Tong Chen, Tung-Tsan Chen, Yung Pei Lin, Chien Lu Jun 2008

Using Factor Analysis To Assess Route Construction Priority For Common Duct Network In Taiwan, Wei Tong Chen, Tung-Tsan Chen, Yung Pei Lin, Chien Lu

Journal of Marine Science and Technology–Taiwan

This study identifies the critical variables for determining route construction priorities (RCP) in a common duct network (CDN) using expert interviews and questionnaire surveys. Statistical analysis is also conducted to check the validation and verification of the survey results. Furthermore, factor analysis is employed to derive 24 priority determinant variables and classify them into five groups, including utility agency, traffic condition, local government, infrastructure project, and site condition. The paired comparison method is then employed to determine the weightings of the five groups. It is found that the utility agency is the most important factor while the site condition is …

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Enhancement Of Shg In Fused Sio2 By Corona Poling Under Water, Water Vapor And Salty Environments, Chun-An Tsai, Jung Ning Wang, Wei-Kuo Chao, Tsung Yuan Cheng, Wan-Rone Liou, Adam Y. Wu Jun 2008

Enhancement Of Shg In Fused Sio2 By Corona Poling Under Water, Water Vapor And Salty Environments, Chun-An Tsai, Jung Ning Wang, Wei-Kuo Chao, Tsung Yuan Cheng, Wan-Rone Liou, Adam Y. Wu

Journal of Marine Science and Technology–Taiwan

We found that optical nonlinearity in SiO2 glass sample can be greatly enhanced when sample is poled in wet and salty environments, and the nonlinearity in the sample can be reduced drastically when sample is washed in water. Possible causes for the observed enhancement and reduction of optical nonlinearity in SiO2 glass are discussed.

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Service Quality Radar Map And Two-Stage Service Quality Score, Kee-Kuo Chen, Ding-Hsun Hsiao, Cheng-Hung Arthur Hsieh Jun 2008

Service Quality Radar Map And Two-Stage Service Quality Score, Kee-Kuo Chen, Ding-Hsun Hsiao, Cheng-Hung Arthur Hsieh

Journal of Marine Science and Technology–Taiwan

In an attempt to portray all information released from the service quality studies the service quality radar map (SQRM), is designed in this paper firstly and a generalized service quality score GSQS follows. GSQS is defined by way of the weighted average of differences between relative frequencies of customers’ performance perception and performance expectation, thus can avoid the problems involved in the gap-based SERVQUAL scale and caused by skewed distributions. A special case of GSQS, the stochastic dominance service quality score (SDSQS) whose ideal come from the second stochastic dominance criterion is used to illustrate how a standardized score can …

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Optimization Of Diffuser Valves, Chin-Tsan Wang, Pi-Cheng Chang, Chien-Cheng Huang Jun 2008

Optimization Of Diffuser Valves, Chin-Tsan Wang, Pi-Cheng Chang, Chien-Cheng Huang

Journal of Marine Science and Technology–Taiwan

In this study, the width of channel, D, and diffuser angle, , at given diffuser width whose value is 100 m will be studied for steady and unsteady flow conditions. By means of a series of numerical simulations, some findings for diffuser valve will be reported. The diffuser valve with a channel width of D = 300 m and diffuser angle =60º, is a better geometry because of its outstanding capability on suction production of net volume flow. Besides, the larger the Reynolds number is, the greater the suction amount of net volume flow will be. When the aspect ratio …

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Cpt-Based Liquefaction Assessment By Using Fuzzy-Neural Network, Shuh-Gi Chern, Ching-Yinn Lee, Chin-Chen Wang Jun 2008

Cpt-Based Liquefaction Assessment By Using Fuzzy-Neural Network, Shuh-Gi Chern, Ching-Yinn Lee, Chin-Chen Wang

Journal of Marine Science and Technology–Taiwan

Because of the increasing popularity worldwide of the cone penetration test (CPT) for site characterization, significant progress on the simplified CPT-based methods has been made for evaluation of earthquake induced liquefaction potential of soils. In this study, a fuzzy-neural network combined with 466 CPT field observations is developed to evaluate liquefaction potential of soils. The proposed model combines fuzzy theory with subtractive clustering algorithm to establish a fuzzy-neural system. The study indicates that fuzzy-neural network can successfully describe the complex relationship between seismic parameters, soil parameters, and the liquefaction potential. The fuzzy-neural network model is found to have very good …

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Investigation On The Blast Resistance Of A Stiffened Door Structure, Ming-Wei Hsieh, Jui-Pin Hung, De-Jen Chen Jun 2008

Investigation On The Blast Resistance Of A Stiffened Door Structure, Ming-Wei Hsieh, Jui-Pin Hung, De-Jen Chen

Journal of Marine Science and Technology–Taiwan

This study was aimed at investigating the blast resistance of a stiffened door structure. For this, a series of finite element transient analysis were performed to predict the dynamic response of blast resistant doors. Current results show that the stiffeners have sustained the majority of the explosive loadings. The effect of stiffener size on the stress state was rated in terms of the ratio of stiffener stress to plate stress, which was enhanced with the increase of web thickness of stiffener. Additional, the highest stresses were shown to occur at the transverse stiffeners near the hinged sides with a maximum …

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Factor Analysis Of Interface Problems Among Construction Parties - A Case Study Of Mrt, Rong-Yau Huang, Chin-Tien Huang, Hung Lin, Wen-Hsiang Ku Mar 2008

Factor Analysis Of Interface Problems Among Construction Parties - A Case Study Of Mrt, Rong-Yau Huang, Chin-Tien Huang, Hung Lin, Wen-Hsiang Ku

Journal of Marine Science and Technology–Taiwan

With the rapid development of technology and the increasingly bigger size of constructions, the involved parties are required to pay more attention to all types of difficult interface problems than ever before. By considering the mass rapid transit system (MRTS) as an example, several problems resulting from complicated mechanical, electrical, civil, and track interfaces led to enormously extra losses in the construction process. Accordingly, this paper intends to use quantitative methods to categorize a variety of interface problems in the MRTS construction projects as well as identify their individual impacts in order to clarify these interface problems. The analysis results …

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Robust Control Of Uncertain Time-Delay Systems Via Sliding Mode Control And Lmi- H∞ Technique, Ming-Chang Pai Mar 2008

Robust Control Of Uncertain Time-Delay Systems Via Sliding Mode Control And Lmi- H∞ Technique, Ming-Chang Pai

Journal of Marine Science and Technology–Taiwan

This paper presents a proportional-integral sliding mode control (PISMC) methodology for a class of linear uncertain systems with state delays. The systems are assumed to have structured, mismatched, and time-varying parameter uncertainties as well as mismatched and bounded external disturbances. Based on Lyapunov stability theorem and linear matrix inequality (LMI) H∞ technique, a sufficient condition is derived to guarantee the global stability of the dynamics and a prescribed H∞ norm bound of disturbance attenuation for all admissible uncertainties. Furthermore, this scheme assures robustness against state delays, parameter uncertainties and disturbances. Finally, an example is given to illustrate the feasibility of …

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Application Of Maximum-Efficiency Tracking Control To Backlight Module Based On Phase-Locked Loop Technique, Chang-Hua Lin, Ying Lu Mar 2008

Application Of Maximum-Efficiency Tracking Control To Backlight Module Based On Phase-Locked Loop Technique, Chang-Hua Lin, Ying Lu

Journal of Marine Science and Technology–Taiwan

Maximum-efficiency tracking control applied in the backlight module is proposed in this paper. The backlight system incorporates a phase-locked loop (PLL) as a feedback mechanism to promote both the system efficiency and stability. To overcome the drawbacks of the conventional electromagnetic transformer and to miniaturize the backlight module, the piezoelectric transformer (PT) is adopted for driving the cold cathode fluorescent lamp (CCFL). To avoid the system efficiency decreases due to the temperature effect of PT, the PLL is utilized to track immediately the optimal operating frequency of PT for achieving maximum output efficiency under various ambient temperatures. The feedback parameter …

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Design And Implementation Of An All-Digital Real-Time Underwater Acoustic Transceiver Using Digital Signal Processors, Fu-Sheng Lu, Ching-Hsiang Tseng, Bin-Chong Wu Mar 2008

Design And Implementation Of An All-Digital Real-Time Underwater Acoustic Transceiver Using Digital Signal Processors, Fu-Sheng Lu, Ching-Hsiang Tseng, Bin-Chong Wu

Journal of Marine Science and Technology–Taiwan

In this paper, an all-digital transceiver for real-time underwater acoustic (UWA) communications is developed using digital signal processors (DSPs). The design of the transceiver is based on the direct-sequence spread-spectrum (DS/SS) modulation scheme, in which the timing synchronization is efficiently achieved by employing a sliding correlator and a modified noncoherent delay-locked loop for code acquisition and tracking, respectively. In addition, an equal-gain combiner (EGC) and an adaptive decision-feedback equalizer (DFE) are included in the receiver to enhance its interference rejection capability under multipath fading environments. Several real-time UWA transmission tests are conducted in an experimental water tank to evaluate the …

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Profile Design Of Piston Ring Using Inverse Method, Li-Ming Chu, Yuh-Ping Chang, Jung-Hua Yang Mar 2008

Profile Design Of Piston Ring Using Inverse Method, Li-Ming Chu, Yuh-Ping Chang, Jung-Hua Yang

Journal of Marine Science and Technology–Taiwan

This study aims to develop an algorithm for designing the piston ring profile and pressure distribution using an inverse method. The proposed algorithm needs to obtain load and boundary conditions for estimating not only a smooth curve in the piston ring profile, but also in the pressure distribution. The algorithm is developed from Reynolds integral and force balance equations. The least-squares error method, variational method, Gauss-Seidel method and Newton-Raphson method are employed to calculate the piston ring profile. Simulation results reveal that the greater the degree of the polynomial function used, the greater the maximum pressure ( Pmax ), load …

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Guaranteed Cost Control Of Uncertain Linear Systems Via Discrete-Time Variable Structure Control, Ming-Chang Pai Mar 2008

Guaranteed Cost Control Of Uncertain Linear Systems Via Discrete-Time Variable Structure Control, Ming-Chang Pai

Journal of Marine Science and Technology–Taiwan

This paper presents a design of realizing the guaranteed cost control problem for uncertain linear systems via discrete-time variable structure control (VSC) scheme. The uncertainties in the system are assumed to be norm-bounded and time-varying. Based on the discrete-time VSC technique, the proposed controller can drive the system into a pre-specified switching surface to obtain the desired dynamic performance and the chattering phenomenon is eliminated. Sufficient conditions for the existence of guaranteed cost control are presented, and the problem of designing guaranteed cost control is converted to a convex optimization problem with linear matrix inequality (LMI) constraints. Finally, simulation results …

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Coagulation Effects On Aerosol Dynamics Along An Isothermal Vertical Flat Plate, Chang-Bin Huang, Cherng-Shing Lin, Shih-Cheng Wang Aug 2007

Coagulation Effects On Aerosol Dynamics Along An Isothermal Vertical Flat Plate, Chang-Bin Huang, Cherng-Shing Lin, Shih-Cheng Wang

Journal of Marine Science and Technology–Taiwan

Aerosol dynamic behavior in a turbulent flow field is investigated in this study. The flow field is a natural convection boundary layer flow adjacent to a heated or cooled vertical flat plate. The main computational method is based on a boundary layer type solution combining the flow field and sectional aerosol simulation. The SIMPLE alogrithm is adopted to solve the flow continuity, momentum, energy, and aerosol concentration equations. Various aerosol dynamic transport and removal mechanisms, including fluid convection, Brownian motion, gravitational settling, thermophoretic drift, and coagulation of aerosols, are considered in the simulation model. Aerosol coagulation effects on particle transport …

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Optimization Of Perforated Doublelayer Absorbers Using Simulated Annealing, Min-Chie Chiu, Ying-Chun Chang, Long-Jyi Yeh, Tian-Syung Lan Aug 2007

Optimization Of Perforated Doublelayer Absorbers Using Simulated Annealing, Min-Chie Chiu, Ying-Chun Chang, Long-Jyi Yeh, Tian-Syung Lan

Journal of Marine Science and Technology–Taiwan

As noise is highly responsible for the psychological and physiological ills to workers, the noise control for enclosed manufacturing system with sound absorber becomes obligatory; besides, considering the maintenance and operation in a room, the minimal thickness of sound absorber is certainly requested, according. To meet these issues, the compromising design target, ratio of sound absorption coefficient to thickness of acoustic panel, is thus proposed and applied as a researched objective, accordingly. In this paper, the simulated annealing (SA) is utilized in the shape optimization of the double-layer sound absorption system. The paper tackles not only the theoretical derivation in …

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Annealing Effects Of Semiconducting Barium-Titanate Thermister, Yeong-Chin Chen Aug 2007

Annealing Effects Of Semiconducting Barium-Titanate Thermister, Yeong-Chin Chen

Journal of Marine Science and Technology–Taiwan

Two Positive Temperature Coefficient of Resistivity (PTCR) ceramics with composition A, (Ba0.997Sb0.003)Ti1.005O3, and composition B, (Ba0.997Sb0.003)Ti1.005O3 + 0.1 mole% MnO2 were fabricated and examined herein. The ceramic grain size, oxygen pressure and annealing time need to be simultaneously controlled to obtain an optimum PTCR resistor. Additionally, the stoichiometric proportions of the constituent elements must be weighted carefully in order to produce good quality PTCR devices. This study thoroughly explores all the factors affecting the PTCR characteristics. Experiments were developed to verify that PTCR phenomena are strongly influenced by oxygen absorption. As the samples were annealed in Air atmosphere, the numbers …

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Characteristic Study Of Mhd Pump With Channel In Rectangular Ducts, Je-Ee Ho Aug 2007

Characteristic Study Of Mhd Pump With Channel In Rectangular Ducts, Je-Ee Ho

Journal of Marine Science and Technology–Taiwan

This study is focused on the prediction of pumping performance in MHD flow. To reach it, an analytic model based on the steady state, incompressible and fully developed laminar flow theory will be provided to analyze the flow characteristic with different scalar dimensions in duct channel. By converting the Lorentz forces which is interacted by electric current and magnetic flux into hydrostatic pressure gradient in the moment equations, the governing equations can be transformed into Poisson equation which makes the analytic solution possible. Furthermore, the concept of flow circuit which is similar to the thermal network in conduction problem will …

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The Dynamics And Control Of An Moving Mass Traveling On An Initially Curved Beam, Chih-Ching Chang, Yi-Ming Wang Aug 2007

The Dynamics And Control Of An Moving Mass Traveling On An Initially Curved Beam, Chih-Ching Chang, Yi-Ming Wang

Journal of Marine Science and Technology–Taiwan

The objective of this paper is to study the dynamics and control of an Euler-Bernoulli beam with an attached mass rolling on an initially curved beam based on a simplified control model. The optimization of the performance index of linear quadratic regulator (LQR) is considered. Three actuators are placed along the beam that provide the necessary forces to control the response of the beam-mass system. Based on Euler-Bernoulli beam theory and Newtonian mechanics, the coupled non-linear equations of motion combining with a simple closed-loop feedback control are obtained. Results of present study show that with appropriate regulator design, the vibration …

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An Analytic Analysis Of W-Cdma Smart Antennas Beamforming Using Complex Conjugate And Doa Methods, Chi-Min Li, Jia-Chyi Wu, I-Tseng Tang Aug 2007

An Analytic Analysis Of W-Cdma Smart Antennas Beamforming Using Complex Conjugate And Doa Methods, Chi-Min Li, Jia-Chyi Wu, I-Tseng Tang

Journal of Marine Science and Technology–Taiwan

Wideband Code Division Multiple Access (W-CDMA) adopts the smart antenna techniques to increase the signal-to-interferencenoise ratio (SINR) and system capacity. In this paper, we statistically derive analytic results to prove the SINR performance for the two commonly used CC and DOA beamforming methods. Results show the both methods will have the same mean SINR performance and CC method will be more robust than the DOA method.

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Pole Placement Design Of Decentralized Output Feedback Power System Stabilizers Using Hybrid Differential Evolution, Yung-Sung Chuang, Chi-Jui Wu, Shu-Chen Wang, Pei-Hwa Huang Aug 2007

Pole Placement Design Of Decentralized Output Feedback Power System Stabilizers Using Hybrid Differential Evolution, Yung-Sung Chuang, Chi-Jui Wu, Shu-Chen Wang, Pei-Hwa Huang

Journal of Marine Science and Technology–Taiwan

The hybrid differential evolution (HDE) has been used to investigate a novel decentralized pole placement design method of output feedback power system stabilizers. Since the local output variables are used as the feedback signals, the stabilizers could be easily implemented. In the design procedures, it wants to place the electromechanical modes within a designated region in the complex variable plane. The HDE method is originally an optimal searching approach. If all electromechanical modes have been moved to the specified region at the convergent steps, the objective function will reach zero, which is the minimum value. The objective function is chosen …

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