Kun Shan University

About: Kun Shan University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Heat transfer & Thin film. The organization has 1992 authors who have published 2928 publications receiving 45685 citations. The organization is also known as: Kūnshān Kējì Dàxué.

High efficiency battery charger with a buck zero-current-switching pulse-width-modulated converter

Abstract: A resonant converter has low switching losses, a small circuit volume and high power density and is also light. High-frequency switching converters have replaced conventional hard-switching converters. This study utilises a buck zero-current-switching (ZCS) pulse-width-modulated converter for battery chargers to manage resonant converters flexibly. An auxiliary switch is inserted into the resonant loop to control the resonant time. The operating modes of the circuit and the equivalent circuits are identified by analysing the operating principles of the charger circuit, based on the turn-on conditions of the active switches. The equations that are used to determine the circuit parameters are obtained from the equivalent circuits. The developed charger provides the advantages of hard-switching and resonant converters with constant-frequency control, reduced resonant time and the operability of all switching components in the charger under a ZCS condition, markedly reducing switching losses. Experimental results reveal the theoretical effectiveness of the developed novel battery charger circuit. The developed battery charger has a practical mean charging efficiency of over 90% and is highly suited to high-frequency operations with high charging efficiency.

Electrically controllable and polarization-independent Fresnel zone plate in a circularly symmetric hybrid-aligned liquid crystal film with a photoconductive polymer layer

Abstract: This work reports a Fresnel zone plate in a circularly symmetric hybrid-aligned liquid crystal (LC) film with a photoconductive polymer layer. An ultraviolet-induced electrodelike pattern of polymer layer under a zone plate photomask results in alternating major and minor portions of external voltage dropping on LC layer in conductive and nonconductive regions, respectively. These effects cause the discrepancy in LC reorientation between adjacent zones, generating a Fresnel zone plate. The focusing of the zone plate is electrically controllable and polarization independent. Additionally, the zone plate has advantages of a zero focusing in the voltage-off state and a very small operating dc field range from 0to0.3V∕μm.

Development of virtual training platform of injection molding machine based on VR technology.

Abstract: Virtual reality has wide applications in many domains in recent years. It supports a real-time, immersive and interactive simulation technology to approve training effect. Injection molding machine is one of the most important but dangerous machines. To ensure safe operation, the development of a complete safe program of training is really essential. This article proposed a visual simulator based on virtual reality for the training of an injection molding machine. It can assist students in learning to operate this machine but without actually handling a real machine.

Web tension control of a start-up process using observer techniques with friction and inertia compensation

Abstract: System friction or rotational roll inertia can cause a problem in estimation of web tension if the process speed and/or its variation are high. Very few literatures have considered both problems in a single article. This paper presents observer-based feedback controllers with friction and inertia compensation to control web tension during system start up. Observer techniques play a dominant role to assure precise estimation of web tension. The proposed observers have a feedback configuration that is also robust against system parameter variations. Simulation and experiment have shown that the proposed controllers without a tension measurement perform well against the friction and inertia disturbances. Observer-based tension feedback control can perform equivalently as well as classical feedback control does using a load-cell transducer.