• 전자공학회논문지CI
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• 제47권4호
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• pp.118-124
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• 2010

본 논문에서는 상황별 RFID(무선주파수식별) 물류 적재 시뮬레이터를 구현하였다. 이를 위하여 RFID의 적용 및 인식률에 영향을 줄 수 있는 환경요소들을 모델링하여 인식률 실험을 체계적으로 수행할 수 있도록 하였다. 실제로 물류 현장에 적용시켰을 때 보다 적은 시간과 비용으로 상황별 최적의 RFID 물류 적재 방법을 찾아 개선한 사례를 제시한다. 물류 현장에서 RFID 인식률을 높이기 위해 본 시뮬레이터를 사용하여 RFID 인식 실험데이터를 축적하였다. 이를 통해 본 논문에서 제안된 시뮬레이터가 시행착오를 줄이고 효과적으로 최적화된 RFID 물류 적용 안을 찾아낼 수 있다는 것을 실험치를 기준으로 증명 하였다.

• The Korean Journal of Ecology
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• 제17권2호
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• pp.159-170
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• 1994

The geographical distribution and soil characteristics of Korean Elaeagnus plants were investigated by literatures, field survey and soil analysis. Deciduous E. umbellata was distributed throughout the Korean peninsula including western and southern islands. Distribution area of evergreen Elaeagnus plants was classified into three groups; E. macrophylla and E. glabra belonged to group l occurring in the southern, western and eastern islands; E. submacrophylla to group 2 occurring in the southern and western islands; E. maritima and E. ankaii to group 3 in the southern islands only. Deciduous E. umbellata appeared euryeciously from poor soil to rich one, whereas evergreen Elaegnus plants appeared stenoeciously in haline soil near coast.

• 한국초전도ㆍ저온공학회논문지
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• 제2권1호
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• pp.31-34
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• 2000

this paper deals with the initial magnetic field decay for a large scale superconducting magnet e.g. NMR/MRI magnet. The high resolution image can not be obained during the periods of the initial field decay. It is known that all superconducting materials have the property of diamagnetism. This diamagnetism is usually explained with the concept of screening current. We assumed that the existence of the screening currebt. we assumed that the existence of the screening current makes the current distribution in the superconducting wire non-uniform. And the initial magnetic field decay is caused steady current state in the view of its pattern. The initial magnetic field decay is caused by the change of the current distribution between the energizing state and persistent current mode. in this paper the theoretical analysis for the current distributions has been introduced for each state. The experiments have been carried out to verify transport currents in order to veperiments, it small at the higher transport current.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.528-530
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• 2000

In this paper, electric field distribution of GIS by changing conductivity of spacer is analysed by the use of 3 dimensional Surface Charge Method. We find electric field distribution inside GIS was much influenced when volume resistance are lower than $10^7[\Omega-cm]$.

• Journal of Information Technology Applications and Management
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• 제13권4호
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• pp.215-235
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• 2006

Recently, Development of IT and digital-tech, and this is becoming factor of digital contents industry development. But, problem that is more suitable e-business model's necessity and quality enemy of distribution web-site to digital contents as transaction this firm dispute by transaction special quality and Payment-system increase of digital contents increases rapidly was risen. In this study, Digital Contents qualify estimation very important persons of digital contents as sequence of study that investigate from target's viewpoint which is serviced through web-site that digital contents is not factors of web-site service method whether digital contents distribution web-site factors effect that is some in customer satisfaction from general viewpoint of actuality digital contents distribution and is the actual proof enemy. This paper's goal that these study finding leads as digital contents industry discusses individual enterprise's success and failure as field of business in quickening period yet but domestic digital contents industry field will be roared and may can have competitive power by enterprises which wish to already started business or inaugurate an enterprise enter in field with successful beginning and direction and develop continuously.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.438-441
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• 1999

One of the most important aspect in developing High-Tc Superconducting Synchronous Motor is producing high-Tc superconducting tapes that withstand the amount of currents that is needed to run the motor with stability. The purpose of this paper is to find the magnetic field distribution inside the motor in order to find out if the high-Tc superconducting tapes operate stably in actual motor operation. With this goal, magnetic field distribution in a detailed model of the actual motor was analyzed through F.E.M. By analyzing the field distribution acquired through the computer simulation, it has been observed whether the high-Tc superconducting tape maintains its superconductivity in actual motor operation. Also, the effects of the flux damper on the motor's operational characteristics and the magnetic field distribution have been analyzed. As a result, it has been proved that the high-Tc superconducting tapes can withstand 600 A turns which is required by the previous simulation aimed at developing this motor. It has also seen that the flux damper reduces armature reactance during the motor operation and change of load, helping the stable motor operation.

• 한국초전도ㆍ저온공학회논문지
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• 제1권2호
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• pp.20-24
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• 1999

The study of HTS(High Temperature Superconducting) bulk in magnetic levitation system requires the calculation of currents distribution in HTS bulk is very important to determine this forces. We have made computer program to find this current distribution and levitation force. J-E relation in HTS bulk is extremely nonlinear, so iteration method must be used to determine the current distribution. We developed the method to determine the current distribution in the unifrom-field model and, using this method, calculated the levitation force in permanent-magnet-levitation model.

• 대한기계학회논문집
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• 제19권5호
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• pp.1259-1268
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• 1995

The stress distribution around micro holes and the behavior of stress interaction between micro holes are considerd in the study. Several conclusions are extracted as follows : (1) The stress interaction varies with the distance e between micro holes. When the two micro holes are spaced in such a manner that theri two closest points are separated by a distance of micro hole radius (e=1), stress distribution is affected by a opposite micro hole in all the closest region. In addition, if two closest points are seperated by twice the distance of a micro hole radius (e=2), stress distribution is affected by a opposite micro hole in the region of -0.8.leq.x/r.leq.0.8 and the interaction effect can be neglected for e=4. (2)If the depth becomes larger than the radius, or the radius varies, the shape and magnitude of stress distribution around micro holes varies. (3) Hoop stress around a micro hole for the two dimensional configuration is larger than that of the three dimensional micro hole located on the surface of material for .theta. < 60.deg., but it is reversed for .theta > 60.deg.

• 전자공학회논문지A
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• 제31A권1호
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• pp.54-60
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• 1994

In this paper, we present the analytical models for the change of the lateral electric field distribution and the velocity saturation region length with the electron trapping of stressed SC-PMOSFET in the saturation region. To derive the hot-electron-induced lateral electric field of stressed SC-PMOSFET. Ko's pseudo two dimensional box model in the saturation region which illustrates the analysis of the velocity saturation region is modified under the condition of electron trapping in the oxide near the drain region. From the results, we have the following lateral electric field in the y-direction, that is, E(y) ES1satT.cosh(y/l) qNS1tT.sinh(y/l)/lCox. It is shown that the trapped electrons influence the field in the drain region. decreasing the lateral electric field. Calculated velocity saturaion length increases with the trapped electrons. increasing the drain current of stressed SCPMOSFET. This results well explain the HEIP phenomenon of PMOSFET's.

• 전기의세계
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• 제30권4호
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• pp.219-226
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• 1981

The magnetic field distribution in saturable iron part of electromagnetic energy conversion divices is defined by the nonlinear quasi-Poisson enquation that is described the electromagnetic field characteristics and satisfied the natural boundary condition. The solution of this equation is obtained by minimizing an energy functional by means of trial function that defined in triangular subregion of two-dimensional field region. As a result, the accuracy of the machine design is increased by use of its solution. In this respect, this study is developed the basic theory to analyze the magnetic flux distribution in saturable iron part and air gap of induction motor that its secondary part is short circuit by the variational principle, the minimized theory of energy functional, the application of F.E.M., and treatment of computer. As theoritical data compared with the practics, the validity of the theory in this study is supported by experimental findings.