• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.64-65
• /
• 2011

The ac power conversion inverter provides the ac power to ECR device for wireless power transfer. In this paper, the operating efficiency of the class-${\Phi}_2$ resonant inverter has been studied through by experiment for optimal design. Its switching frequency is 1MH and the input voltage is 96V which is the output voltage of LLC resonant converter. And its output voltage is 230Vp-p. The efficiency is measured up to 84%.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.2
• /
• pp.264-268
• /
• 2009

In this paper, the two PCB design method results of boost converters are simulated with same circuit device parameters. One is modeled with microstrip structure and the other is modeled two layers structure without reference plane. Between devices of each circuit are routed 5 centimeters. When the switching frequency is operated 100kHz, the overshoot by signal reflection and the noise characteristics by frequency spectrum for the output voltage and current of the power switch is compared and analyzed using simulation.

• Industrial Engineering and Management Systems
• /
• v.3 no.2
• /
• pp.116-122
• /
• 2004

This paper presents a process plan selection model with multiple objectives. The process plans for all parts should be selected under multiple objective environment as follows: (1) minimizing the sum of machine processing and material handling time of all the parts considering realistic shop factors such as production volume, processing time, machine capacity, and capacity of transfer device. (2) balancing the load between machines. A multiple objective mathematical model is proposed and an evolutionary algorithm with the adaptive recombination strategy is developed to solve the model. To illustrate the efficiency of proposed approach, numerical examples are presented. The proposed approach is found to be effective in offering a set of satisfactory Pareto solutions within a satisfactory CPU time in a multiple objective environment.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.569-572
• /
• 2007

In this paper, research about SVM(stack voltage monitoring) module is written, which studied to detect the failure mode of stack and stop stack driving. It is important role for SVM module to monitor the cell voltage and also, transfer those data to Supervisor controller. SVM module needs accurate measurement to detect failure mode, because the cell voltage is very small value under a few [V]. For improving these cost and technical efficiency, the electric characteristic experiment is made with the measurement circuit designed by using precision resistor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.375-380
• /
• 2002

As the data storage device market demands higher data transfer rate with higher track density. TMR budget is to be tighter so that even minor improvement is sought in HDD development fields. Disk flutter associated with the turbulent air flow inside the chamber becomes of great interest for the reduction of PES especially at OD. A comparative transient turbulent flow study is presented in this paper for the reduction of disk flutter with different housing designs.

• Vacuum Magazine
• /
• v.3 no.1
• /
• pp.16-21
• /
• 2016

FinFETs are able to be scaled down to 22 nm and beyond while suppressing effectively short channel effect, and have superior performance compared to 2-dimensional (2-D) MOSFETs. Bulk FinFETs are built on bulk Si wafers which have less defect density and lower cost than SOI(Silicon-On-Insulator) wafers. In contrast to SOI FinFETs, bulk FinFETs have no floating body effect and better heat transfer rate to the substrate while keeping nearly the same scalability. The bulk FinFET has been developed at 14 nm technology node, and applied in mass production of AP and CPU since 2015. In the development of the bulk FinFETs at 10 nm and beyond, self-heating effects (SHE) is becoming important. Accurate control of device geometry and threshold voltage between devices is also important. The random telegraph noise (RTN) would be problematic in scaled FinFET which has narrow fin width and small fin height.

• Explosives and Blasting
• /
• v.16 no.3
• /
• pp.35-48
• /
• 1998

An overview of the plasma rock fragmentation system, the first commercial application of plasma blasting, is presented. Plasma blasting is based on the fast delivery of stored electrical energy to fracture the rock. The capacitor bank, switching device, cable and blasting electrode employed in the system are described. Utilization of the chemical energy delivered from the electrolyte and the development of a large charge transfer switch using pseudospark enabled the commerciailzaion. The vibration and noise level of the blasting is acceptable in the most ground breaking.

• Journal of the Korean Society of Industry Convergence
• /
• v.11 no.2
• /
• pp.65-70
• /
• 2008

This study presents gas turbine cooling blade by using experimental and numerical works. The review cover researches related to cooling channels using finite element method in rotating blade. Also, the film cooling device and the heat transfer of the external surface of the blade are included. In addition, several methods to be used for the design of the blade, numerical method and experimental techniques are introduced. This work will contribute to improving the manufacturing of engine and the efficiency of gas turbine engines.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.415-418
• /
• 2011

It is critical to assess the characteristics of flame response to pressure perturbations for the understanding of nonlinear combustion instabilities. Previous studies can be grouped into flame response upon perturbed, fresh air and fuel mixture, and flame response directly perturbed from longitudinal waves. The present study presents experimental methodology for the understanding of the flame response exposed to transverse acoustic waves generated by loud speakers.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.7
• /
• pp.43-48
• /
• 2008

The characteristics of heat transfer of the bimetal disc for over-current protection device is specified. Bimetal consists of two metals which have a different thermal expansion coefficient. To analyze the thermal characteristics, temperature distribution when bimetal acts as a switch is calculated. As usual, heat source is applied to the bimetal and electric current is heat source in the over-current protection switch. In this paper, thermal distribution are obtained by solving a coupled electro-thermal field with 3D finite element method.