• Proceedings of the CALSEC Conference
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• 1997.11a
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• pp.53-58
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• 1997

본 논문에서는 통합 Logistics Center라는 새로운 조직을 통해서, 생산, 영업 및 물류를 총괄하여, 전체 공장과 전체 DC/SB의 재고량을 줄이고. 결품현상 방지, 수송비용 절감을 도모할 수 있는 통합 물류 시스템을 구축하는데 필요한 각 Process 및 이를 수행할 수 있는 발견적 해법을 개발하는 것을 연구한다. 생산(공장)에는 가장 정확한 각 DC/SB의 수요 예측량을 토대로 수립된 발주량과, 이 발주량을 통해서 결정된 생산의뢰 계획을 제공한다. 이 생산 계획은 제품이 생산되어서 출고될 때, 근거리 지역에 있는 DC/SB에 출고될 수 있도록, 각 공장의 전용라인에 대해서는 최소 수송비용을 고려한다. 제품의 혼합생산 라인의 정보( 생산 Capa.)를 이용하여 나머지 발주량을 생산 의뢰 계획으로 바꾸게 된다. 공장에서는 이 계획을 바탕으로 생산 계획을 수립하여, 그 계획과 생산된 제품을 DC/SB로 출고시킨다. 공 장의 출하 가능량과 각 DC/SB의 2주전의 발주량은 실제 많은 차이가 발생하므로, 이를 재조정하여, 공장의 재고를 최소로 하는 방향으로 공장의 출하 가능량을 조절한다. 조절된 출하 가능량은 2일간의 근거리 수송 원칙에 의해서 입고될 DC/SB를 결정한다. 공장의 출고를 돕기 위해서 배차계획을 수립한다. 본 연구에서는 각각의 Process Engine들의 활동과 정보의 흐름이 서로 상이한 시간 간격으로 발생할 때 각 Process Engine 의 Input/output으로 사용되는 정보의 효율적인 Systematic 동기화 및 Database와 interface 및 Multi-Tasking Database Transaction을 고려할 것이다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.9
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• pp.873-882
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• 2013

The effective way of estimation and analysis of EMI(Electromagnetic Interference) in Wireless Power Transfer System operating at 13.56 MHz is proposed. In this paper methodology of driving magnetic field strength and electric loop current of two antennas which are in free space and on PEC plane using image theory and duality is proposed. Perfect electric conductor(PEC) is planar, infinite in extent, and perfectly conducting plane. And we will refer it as PEC plane. A equivalent circuit model is used to analyze. Using this theoretical analysis, we can derive maximum magnetic field strength of the far-field region numerically using measured data of near-field maximum magnetic field strength. The experimental results using commercial numerical simulation tool are in agreement with the theoretical results. Also, using the derivation of maximum magnetic field strength in the far-field region, we can easily estimate the maximum allowable power dissipation that meets EMI regulations.

• Journal of the Korean Magnetics Society
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• v.27 no.2
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• pp.63-69
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• 2017

Naval ships are particularly required to maintain acoustic and magnetic silence due to their operational characteristics. Among them, underwater magnetic field signals derived by ships are likely to be detected by threats such as surveillance systems and mine systems at close distance. In order to increase the survivability of the vessels, various techniques for reducing the magnetic field signal are being studied and it is necessary to consider not only the magnitude of the magnetic field signal but also the gradient of it. In this paper, we use the commercial electromagnetic finite element analysis tool to predict the induced magnetic field signal of ship's scaled model, and arrange the degaussing coil. And the optimum degaussing current of the coil was derived by applying the particle swarm optimization algorithm considering the gradient constraint. The validity of the optimal degaussing technique is verified analytically by comparing the magnetic field signals after the degaussing with or without gradient constraint.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.613-618
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• 2019

EMF (Electromagnetic Field) is a valuable resource for living in a knowledge-based information society. The EMF is used in home appliances that make our lives easy and convenient, and in telecommunication devices such as mobile phones, personal computers, medical devices and broadcasting towers. However, the biological hazards associated with EMF exposure are also increasing in signal from telecommunication devices. Studies of the effects of EMF exposure on humans have been conducted for a long time, but it has not yet been demonstrated whether the EMF effect is harmful. In this paper, we examine the electromagnetic field emitted from various electronic devices around living and its effect.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1231-1239
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• 2006

In this research magnetic field reduction effect of each passive loop was analyzed by using the scale down models of transmission lines. This paper examined magnetic field reduction effect of the passive loop that will be applied to actual facility through the experiment, which is about double vertical transmission line and horizontal transmission line. Consequently, by confirming the fact that magnetic field reduction effect can be obtained to 50 % by passive loop without reactive compensation, we insured technology about application of passive loop. And the case of 3 turns of loop showed two times reduction effect than that of 1 turns of loop in reducing magnetic field. Vertical passive loop is more efficient than horizontal passive loop in the aspect of reducing magnetic field on double vertical transmission lines. What is more, vertical passive loop showed good effect of reducing magnetic field in a far distance as well as in a short distance.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.26-31
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• 1978

The objective of the present study was to investigate the effect of nicotine-contaminated mulberry-leaf, which was grown in the vicinity of tobacco drying plant (TDP), on cocoon crop. Mulberry-leaf harvested from the field at Sericultural Experiment Station (SES), Suweon, Korea, was used as control, supposedly nicotine-free leaf. Leaf harvested from the field in the distances of 30-50m, 300-400m and 700-800m from TDP was fed during the whole larval stage of the silkworm at. SES. The effect of leaf in each treatment level on the quantitative characters of the silkworm was summarized as follows; 1. Larval duration from 4th instar on was significantly longer in the TDP-leaf treatments than for the control. 2. Duration of matured silkworm appearance became longer as the distance of the mulberry-field from TDP got shorter, because the larval duration and growth of the silkworm were not uniform in the TDP-leaf treatments. 3. Mortality rates during the late larval, cocoon spinning, and pupal stages were highest for the 30-50m leaf, especially mortality rates during the late larval and pupal stage were serious. 4. Pupation rate was lowest for the 30-50m leaf and those for the 300-400m and the 700-800m leaf were not significantly different from that of the control. 5. Nicotine damage to cocoon weight and cocoon shell weight was significant in each TDP-leaf level. Cocoon shell ratio was reduced at the same extent in each level, compared with the control. 6. The ratio among cocoon-classes was significantly different between treatments, compared with best-cocoon ratio of 87.1% for the control. Cocoons were not uniform for the 30-50m leaf, and those for the 300-400m and the 700-800m leaf were as almost uniform as those for the control. 7. Loss of fresh cocoon yield became greater as the distance of the mulberry-field from the TDP-got shorter. In conclusion, the critical distance of mulberry-field, which influences larval health, cocoon quality and yield, appeared to be 800m from the TDP. Such other factors as wind direction and topographic location may be involved in the critical distance. 8. From the present experiment, we could obtain only the effect of nicotine on the silkworm through digestive system, since the silkworm was raised at SES in Suweon. If the silkworm.. were raised in the vicinity of the TDP, poison effect of nicotine on the silkworm could beo expected through exoskeleton and tracheal system as well as through digestive system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.1
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• pp.44-52
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• 2014

In this study, the influence of the near field, far field and radiation directivity of microstrip patch antenna when is used mushroom EBG(Electromagnetic Band Gap) as ground is investigated. Using characteristic of dispersion diagram of mushroom EBG, we calculated forbidden band(2.36GHz-2.85GHz) given mushroom type EBG microstrip antenna(2.45GHz) having 2-layer EBG that is operating within forbidden band. In oder to conform performance enhancemen of antenna using EBG ground, we have compared with the antenna using PEC(Perfect Electric Conductor) ground. We could know about 2.74dB increment of the radiation directivity, because EBG can suppress surface wave that is generated at interfaces of the dielectrics-conductor.

• Journal of Korean Society of Transportation
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• v.15 no.2
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• pp.7-23
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• 1997

본 연구의 목적은 설문조사를 통해 주민들이 실정에 맞는 거주자우선주차제의 실행 요건을 결정하는데 있다. 연구의 구성은 제2장에서 거주자우선주차제의 이론적 배경을 검토 하고, 제3장에서는 실행요건의 결정을 위한 연구분석의 틀을 제시하며, 제4장에서는 설문조 사의 방법과 조사내용에 대한 분석결과를 제시한다. 마지막으로 제5장에서는 결론과 정책건 의로 맺음한다. 이론적으로 분석결과 거주자우선주차제는 주차수요관리와 주차장공급촉진이 라는 2원적인 목표를 내재하고 있는 것으로 나타났다. 그결과 허가요금, 시행시간대 등의 실 행요건을 결정하는데 있어서 다양한 외부요인들을 고려하여야 할 필요가 있으며, 외부요인 들은 거주자들의 사회경제적 특성, 주거환경적특성, 주차행태적 특성, 기타특성 들로 구성된 다. 실행요건을 결정하기 위해 주민들에 대한 설문조사를 실시하였고 그 분석결과는 다음과 같다. 1) 요금수준 결정시 차고지 공급 목적일 경우 높은 수준의 요금을 부과하되 지역적 소득수준을 감안 하여야 하며, 목적이 수요관리에 있을 때는 외부인에 대한 규제만 하면 되 기 때문에 주민들에게는 무료이거나 가능한 낮은 요금을 징수하는 것이 바람직하다. 2) 공 간적 범위는 주민들의 근거리주차 선호 때문에 블록단위 또는 세가로를 중심으로 시행하되, 집앞돌폭이 4m 미만이거나 8m 이상일 경우에는 공간적 범위를 넓게 잡는 것이 바람직 할 것이다. 3) 주차면 배정은 독점적 사용권을 부여하는 방식이 공공재의 사유화라는 부작용 및 주차면의 비효율적 사용이라는 측면이 있기 때문에 가능한 공동이용방식을 채용함이 바 람직 한 것으로 나타났다. 4) 외부인 주처허가는 전용주택가 지역에서는 허용하여도 그리 큰 문제는 없을 것이나, 외부인 주차수요가 많은 지역에서는 무조건적 허락보다는 요금지불, 주차확인증과 같은 제도적 보완을 통해 허용해야 한다. 5) 시행시간대 결정시 전용주거지역 에서는 야간만 실시하여도 문제가 없으나 그외 지역에서는 주차수요를 고려하여 주간 또는 전일로 시행할 필요가 있다. 특히 주차문제가 하루종일 발생하는 경우와 출퇴근시 주차문제 가 많은 곳에서는 하루종일 시행할 필요가 있다. 그러나 차고지 확보율이 지나치게 낮은 곳 에서는 야간시 주민반대에 부디칠 가능성이 크기 때문에 차고지 여건이 개선될 때 까지는 시행을 보류할 필요가 있을 것으로 판단된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.314-319
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• 2012

In this paper, a repeater antenna operating at MICS and ISM bands is proposed and the antenna performance including the human body effect is investigated. The proposed antenna is composed of a ZOR(Zeroth Order Resonator) and a loop antenna. A loop antenna is operated at ISM band and a loop antenna capacitively coupled with a ZOR acts as an antenna for MICS band. Simulation was carried out in order to analyze the effects of human body on antenna performance when a human body is located in the near field of an antenna. According to the simulated and measured results, the proposed antenna has -10 dB $S_{11}$ bandwidth wide enough to cover both MICS and ISM bands. The measured peak gains are -28.53 dBi and 3.85 dBi at MICS and ISM band, respectively. The dual band and radiation properties of the proposed antenna are well suited for the WBAN repeater system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1084-1090
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• 2009

This paper presents a balun consisting of a T-junction, a Right/Left Handed Transmission line(RLH-TL), and a conventional Right Handed(RH) line. It is assumed that the RLH-TL consists of N unit-cells. We provide closed-form solutions and design a very compact wideband(80 %) balun using CPW lines based on the obtained solutions. Then, we propose a capacitively loaded loop antenna designed for a uniform current distribution. The antenna resistance of the proposed antenna at resonance is about 204 ohms. The length of the unit cell is about $\lambda/12$(total length: $1\;\lambda$). The magnetic field generated from the proposed antenna is stronger than that of the conventional one by as much as 20 dB. We used a coplanar strip line(CPS) to combine the loop antenna and balun. The proposed antenna may be used as a near field UHF RFID reader antenna.