• Journal of Magnetics
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• 제19권2호
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• pp.146-150
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• 2014

The objective of this paper is to provide a comparison between two transverse flux rotary machines (TFRM) with different topologies of stator cores. Depending on how to make stator core with laminated steel sheets, the one topology is 'perpendicular stacking core' and the other is 'separated core'. Both of the two cores have been designed considering 3-dimensional (3-D) magnetic flux path with the same output power conditions, but the core losses are quite different and it causes different magnetic and thermal characteristics. For comparison of these two topologies of stator cores, therefore, core losses have been calculated and used as a heat source in no-load conditions, and the thermal stress has been also calculated. 3-D finite element method has been used for the magnetic field, thermal, and stress analysis to consider the 3-D flux path of the TFRM. After comparing the analysis results of the two topologies, experimental results are also presented and discussed.

• International Journal of Railway
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• 제4권4호
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• pp.103-108
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• 2011

The effect of the core cell shape on shock absorption characteristics of biomimetically inspired honeycomb structures has been numerically investigated. The finite element models of honeycomb test specimen composed of five core cells of identical mass have been constructed, and numerical simulations have been run on PAMCRASH. The dimensions of the sides of core cells as well as the angle between the sides have been shown to influence the shock absorption characteristics of the honeycomb structure. The specimen with regular hexagonal core cell shape is found to show the best shock absorbing capacity, and specimen with rectangle-like core cell are found to provide good shock absorbing characteristics.

• Journal of Magnetics
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• 제22권1호
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• pp.93-99
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• 2017

The effort attempts to investigate the influence of various non-oriented electrical steel sheets on the core loss of a switched reluctance motor (SRM). The core loss of the motor inherits a strong correlation with flux density and permeability of the material. The study involves the use of laminated 2.7 % high silicon steel suitable for the motor in view of its higher flux density and lower core loss. The accurate prediction of core loss leaves way to suggest measures for improving the performance of the SRM. The dynamic simulation measurements of a 1.5 kW, three-phase 12/8 SRM involve the finite element method (FEM) and use the data obtained experimentally from Epstein frame. The closeness of the simulated and hardware results obtained with laminations of M400-50A, DI MAX-M19 and DI MAX-M15 both for the stator and rotor, espouse a greater significance to the findings in terms of the core loss density and forge new dimensions for its use in the drive industry.

• Journal of Information Technology Applications and Management
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• 제12권2호
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• pp.45-61
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• 2005

Recently, increasing attention has been paid to IT outsourcing and core competency of the corporation. Many companies are expected to focus on core competency rather than reduce IT cost from IT Outsourcing. But, by this time there are no a framework for evaluating intensity of core competency and maturity of IT outsourcing capability. This paper is conducted to provide a framework for evaluating intensity of core competency and maturity of IT outsourcing capability. This paper is to verify if the company's core competency and IT outsourcing capability have a significant influence on each other.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1290-1295
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• 2014

In this paper, various configurations of octagonal wound transformer core topology, which has previously proved advantages on conventional wound cores, are studied. Each configuration has different joint types and different placement of joint zones on the core. Magnetic flux distributions and power losses of each configuration are analyzed and compared. Comparisons are based on both 2D&3D finite element simulations and experimental studies. The results show that, joint types and their placements on the core cause local flux accumulations and dramatically affect power loss of the core.

• 한국안전학회지
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• 제17권4호
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• pp.133-139
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• 2002

Core-shell polymers of inorganic/organic pair, which are consisted of both core and shell component, were synthesized by sequential emulsion polymerization using ethyl methacrylate (EMA) as a shell monomer and ammonium persulfate as initiator. We found that $CaCO_3$ core should be prepared by adding 2.0wt% SDBS(sodium dodecyl benzene sulfonate), $CaCO_3$ core/PEMA shell polymerization was carried out on the surface of $CaCO_3$ particle during EMA shell polymerization in the core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring the degree on decomposition of $CaCO_3$ by HCI solution, thermal decomposition of polymer composite on thermogravimetric analyzer, glass transition temperature on differential scanning calorimeter, and morphology using scanning electron microscope.

• 한국통신학회논문지
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• 제16권1호
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• pp.57-63
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• 1991

본 논문에서는 이중형 코어(Dual Shape Core)를 갖는 W형 단일모드 광섬유의 전파특성을 이론적으로 조사하였다. 스칼라 근사화방법을 이용하여 넓은 파장범위에서 저분산을 갖는 이중형 코어 W 형 단일모다 광섬유의 설계변수를 계산하였다. 그 계산결과를 단일형코어를 갖는 기존의 W형 광섬유와 비교하였을 때 보다 큰 코어반경을 갖고, 코어내의 모드필드의 접속효과가 보다 큼을 확인하였다.

• 한국자원식물학회지
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• 제21권3호
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• pp.222-225
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• 2008

Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.

• 한국응용과학기술학회지
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• 제22권2호
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• pp.96-105
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• 2005

Core-shell polymers of methyl methacrylate-styrene system were prepared by sequential emulsion polymerization in the presence of sodium dodecyl benzene sulfonate(SDBS) as an emulsifier using ammonium persulfate(APS) in an initiator and the characteristics of these core-shell polymers were evaluated. Core-shell composite latex has the both properties of core and shell components in a particle, whereas polymer blends or copolymers show a combined physical properties of two homopolymers. This unique behavior of core-shell composite latex can be used in various industrial fields. However, in preparation of core-shell composite latex, several unexpected matters are observed, for examples, particle coagulation, low degree of polymerization, and formation of new particles during shell polymerization. To solve this matters, we study the effects of surfactant concentrations, initiator concentrations, and reaction temperature on the core-shell structure of PMMA-PSt and PSt-PMMA. Particle size and particles distribution were measured by using particle size analyzer, and the morphology of the core-shell composite latex was observed by using transmission electron microscope. Glass temperature was also measured by using differential scanning calorimeter. To identify the core-shell structure, pH of the composite latex solutions was measured.

• 한국인터넷방송통신학회논문지
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• 제12권5호
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• pp.123-128
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• 2012

최근에 이르러 디지털 시스템의 성능을 극대화하기 위하여, 멀티코어 프로세서가 상용화 되어 널리 이용되고 있다. 이러한 멀티코어 프로세서를 구성하는 단위 코어의 성능을 높이면, 적은 개수의 코어를 가지고 시스템의 성능을 크게 향상시킬 수가 있다. 본 논문에서는 순차실행 방식의 수퍼스칼라를 단위 코어로 하는 멀티코어 프로세서 아키텍쳐를 제안하였다. 그리고, 윈도우 크기가 4에서 16이고 2-코어에서 16-코어로 구성되는 멀티코어 수퍼스칼라 프로세서에 대하여, SPEC 2000 벤치마크를 입력으로 하는 광범위한 모의실험을 수행하였다. 모의실험 결과, 윈도우의 크기가 16일 때 16-코어 수퍼스칼라 프로세서는 1-코어 수퍼스칼라 프로세서보다 8.4배의 성능 향상을 가져왔다. 또한, 같은 코어 개수를 가진 멀티 코어 수퍼스칼라 프로세서의 성능이 멀티코어 RISC 프로세서의 성능의 2 배를 기록하였다.