• World Technopolis Review
• /
• v.5 no.1
• /
• pp.61-70
• /
• 2016

Entrepreneurship development has increasingly become a global solution to address the problem of rising unemployment. Science, Technology and Innovation (STI) have become important tools in improving the economic performance and social well-being of nations. When universities and industry work together to push the boundaries of knowledge, they become a powerful engine for innovation and economic growth. This paper is based on focus group interviews and discussions conducted with key players involved in the HIT-Sandown-UNDP Business Incubation Programme in Harare Zimbabwe. The business incubation project sought to support young Zimbabweans to transform their technical prototypes into commercially and socially viable ventures. As a result, a total of 10 prototypes were refined and investor ready business plans were developed for capital sourcing purposes. It was only through the coming together of the partners that real transformation of the lives of the participants was achieved through learning valuable business skills, coaching and mentoring. University-industry partnerships are a useful vehicle of setting up sustainable business incubation centres.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.441-442
• /
• 2016

본 연구에서는 상용차의 무시동시 에어컨용 공진형 컨버터의 고주파 변압기 설계에 대하여 다룬다. 고주파 변압기에 적합한 코어 선정과 Area Product Ap에 의한 코어 형상 파라미터 선정법을 도출하고, 표피효과를 줄이기 위한 권선의 재질과 안정한 직류출력 전압을 얻기 위한 변압기 권선비를 제시한다. 설계된 변압기를 MAXWELL로 모델링하고 누설자속 분포를 확인한다. 공진형 컨버터에 설계된 변압기를 적용한 결과, 변압기 인덕턴스와 출력배압회로의 커패시터간의 공진이 잘 이루어짐을 확인할 수 있었다.

• Proceedings of the KIPE Conference
• /
• 2013.11a
• /
• pp.173-174
• /
• 2013

본 논문에서는 단상 전원과 고정자가 직접 연결되고 회전자에는 독립된 하나의 인버터가 적용되는 전동기 구동 시스템에 대한 분석을 진행한다. 이와 같은 전동기 구동 시스템의 구조는 양방향 운전이 가능하며, 인버터의 직류단 전압을 자유롭게 제어할 수 있다. 또한 입력단에 어떠한 추가적인 장치도 요구하지 않으므로 전동기를 단상 계통에 직접 연결할 수 있어 가전 제품의 적용에 용이하다. 본 논문에서는 이러한 권선형 전동기의 구동 방식을 설명하고, 세탁기 운전을 그 목표로 하여 권선형 전동기의 설계 및 FEM 시뮬레이션을 진행한다. 시뮬레이션은 Maxwell 로 설계된 전동기 FEM 모델을 Simplorer 시뮬레이션을 통해 연동해석을 진행하였다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.131.2-131.2
• /
• 2015

마이크로웨이브를 이용한 플라즈마는 효율적인 전자가열이 가능하며, 낮은 이온에너지를 가지는 고밀도 플라즈마를 생성시킬 수 있다는 장점이 있다. 최근 산화물 반도체 및 대화면 디스플레이 장치내 소자의 보호막 증착용으로 저온 PECVD (Plasma Enhanced Chemical Vapor Deposition) 공정 및 장치의 필요성에 따라 마이크로웨이브를 이용한 PECVD 장치가 주목 받고 있다. 본 연구에서는 실리콘 나이트라이드 공정 장치 개발을 위한 2차원 시뮬레이션 모델을 완성하였다. Global modeling을 이용하여 확보한 Chemical reaction data에 대한 검증을 하였다. Maxwell's equation, continuity equation, electromagnetic wave equation 등을 이용하여 Microwave의 파워 및 압력에 따른 전자 밀도, 전자 온도등의 플라즈마 변수의 변화를 관찰하였다. 또한 Navier Stokes equation을 추가하여 챔버 내의 Gas flow의 흐름을 고려한 시뮬레이션을 진행하여 분석하였다.

• Proceedings of the KSME Conference
• /
• 2001.06e
• /
• pp.430-435
• /
• 2001

This paper introduces a pressure correction method for microflow computation. Conventional CFD methods with no slip boundary condition fail to predict the rarefaction effect of the wall when simulating gas microflows in the slip-flow regime. Pressure correction method with an appropriate slip boundary condition is an efficient tool in analyzing microscale flows. The present unstructured SIMPLE algorithm adopts both the classical Maxwell boundary condition and Langmuir boundary condition proposed by Myong. The simulation results of microchannel flows show that the proposed method has an effective predictive capability for microscale flows.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.05b
• /
• pp.47-50
• /
• 2002

The displacemant current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. With Maxwell-displacement-current-measuring method, the phase transitons of $Poly-{\gamma}-benzyl_{L}$ -glutamate (PBLG) and $Poly-{\gamma}-benzyl_{D}$-glutamate(PBDG) on a water surface were detected. Measured surface pressure, displacement current and dipole moment of monolayers of PBLG and PBDG on the water surface. Also, we measured that compression velocity (30, 40, 50[mm/min]) when the sample spread volume was about 370[ul]-400[ul] and displacement current that occur when differed temperature. From the result, it is known that current is generated in the range of high surface pressures as compression velocity become faster and increase of temperature.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.3
• /
• pp.106-114
• /
• 1998

Cogging torque is often a principal source of vibration and control difficulty in permanent magnet motors, especially at low speeds and loads. For example, reduction of cogging torque is an important specification for DC motors used for electric power stee- ring. This paper examines two motor design techniques, stator tooth notching and rotor pole skewing with magnet pole shaping, for reduction of cogging torque, and the effect of each method on the airgap flux, and the use of the Maxwell stress method and Fourier decomposition to calculate the periodic cogging torque. The analyses show that the cogging torque can be nearly eliminated by the suggested designs, with minimal scacrifice of output torque.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.3
• /
• pp.91-96
• /
• 1998

The saturated fatty acids(arachidic acid, stearic acid, and palmitic acid) were repeatedly applied on water surface, and their ${\pi}-A$ isotherms and Maxwell displacement current(MDC) were measured to identify the effect of the number of carbons of fatty acids on the properties of Langmuir films. The saturated fatty which contain higher carbon number showed higher MDC peak, and the less carbon it contains, the higher surface pressure they show. It was found the maximum of MDC peaks was as the molecular area just before the surface pressure increases in compression cycles of saturated fatty acids.

• Proceedings of the KIEE Conference
• /
• 1991.11a
• /
• pp.122-125
• /
• 1991

This paper deals with hysteresis losses on the superconducting slap by using type II superconducting theory and classical maxwell equations. Transport current is transmitted to the longitudual direction and applied magnetic field is perpendicular to the slap length and simultaneously parallel to the plat. And the sinusoidal transport currents and the magnetic fields are applied to the slap. Properties of hysteresis loss can be understood, using computer simulation with apply field, transport current and phasor difference. From this result the efficiency and the stability of superconducting system can be enhanced.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.37-42
• /
• 1990

In order to obtain optimal design criteria and operating parameters, a Single-sided Linear Induction Motor (SLIM) is analysed by using a 2-D finite element method with magnetic and current vector potential. In the analysing procedures, the governing equation is derived from Maxwell's equation combined with the magnetic vector potential. As a forcing term, 3-phase voltage source is employed using the Kirchhoff's voltage law in order to look into effects of the unbalanced 3-phase currents and air gap flux density. Also, 2ndary eddy current distribution, longitudinal end and transverse edge effects are in turns visualized by flux lines in 3 different analysing planes as functions of frequency and input power.