• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 1부
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• pp.225-227
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• 2010

본 논문은 OFDM 방식의 고속 광대역 모뎀의 주파수 오프셋을 추정하고 보상하는 알고리즘에 관한 것이다. 설계된 주파수 오프셋 추정 및 보상 알고리즘은 프리앰블 구간에서 초기 CFO(carrier frequency offset)를 추정 및 보상하고, 데이터 전송구간에도 잔류 CFO를 추정하고 보상하도록 동작한다. 초기 CFO보상은 시간축에서 동작하고, 잔류 CFO 보상은 FEQ 뒤에서 파일럿 캐리어의 정보를 이용하여 이루어진다. 잔류 주파수 오프셋을 보상할 때에는 ADC/DAC의 SFO(sampling frequency offset)도 추정하여 잔류 CFO와 동시에 보상하게 된다.

• 무역상무연구
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• 제43권
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• pp.297-336
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• 2009

In modern industrial society carriage of dangerous goods by sea becomes more increasing than ever before. Dangerous goods are required for special care and handling in that shipment of dangerous goods could affect safety of the vessel and other cargoes. It is also true that dangerous goods could be used as a means of terrorism. his article investigates allocation of risk and liabilities between parties involved in the carriage of dangerous goods by sea. More specifically, this study examines principles of strict liability of the shipper in shipment of dangerous goods with some limitations based upon recent cases. Furthermore this article investigates the issues on identity of shipper who bears strict liability to the carrier where there exist actual or documentary shipper other than the contractual shipper. Lastly, whether it is reasonable that the transfer of strict liability to the transferee, who does not have opportunity to verify dangerous nature of the goods before shipment, by endorsing bills of lading will be discussed critically.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2007년도 춘계학술발표논문집
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• pp.136-138
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• 2007

본 연구에서는 유기박막트랜지스터 (OTFT, Organic Thin film Transistor) 제작을 위한 채널막으로 pentacene의 soluble 공정 과 soluble 공정 올 통하여 제작된 pentacene 박막의 특성 을 분석 하여 유기박막트랜지스터에 적용 여부를 조사하였다. Pentacene을 용해시키기 위한 용제로는 toluene과 chloroform을 사용하였으며, 각각의 용제에 대하여 열처리를 하여 pentacene 용액을 준비하였다. Spin-coating 법으로 pentacene 유기 박막을 제작하여 각 박막의 결정화 특성을 관찰하였다. XRD 회절 분석 결과 chloroform 올 이용한 pentacene 박막에서만 결정화가 된 것이 확인이 되었다. Hall effect measurement 분석 결과 chloroform올 이 용한, pentacene 박막의 전하농도 (Carrier Concentration)는 $-3.225{\times}1014(c{\cdot}cm^{-3})$를 나타내었고, 이동도 (Mobility)는 $3.5{\times}10^{-l}(cm^2{\cdot}V^{-1}{\cdot}S^{-1})$를 각각 나타내었다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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• pp.315-322
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• 1998

It is discussed how to route yard-side equipment during the loading operation in port container terminals. The number of containers to be picked up at each yard-bay, as well as the route of a yard-side equipment (for example, transfer crane or straddle carrier) in a yard, are determined. The objective of the problem is to minimize the total container handling time in the yard. An encoding method to represent nodes in the search space is introduced utilizing inherent properties of the optimal solution by which the search space is greatly reduced. A beam search algorithm is suggested. A numerical experiment is carried out to compared the performance of the beam search algorithm with those of other approaches.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.539-544
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• 2001

The holographic measurement techniques can be applied to various industrial fields such as automobile, airplane, construction, electronics, medical, mechanics and physics. The visualization of fluids is very important in aerodynamics, heat transfer and stress analysis. There are classically optical methods such as shadowgraph, schlieren method, and Mach-Zehnder interferometry for visualizing the fluid flow phenomena. But, it is difficult to understand the continuous state of fluids well in those methods. In this study, the real-time holographic interferometer with high-speed camera is applied to the flow visualization. In addition, collimated laser beam and rotating wedge are used for recording and formation of carrier fringes, respectively.

• Membrane and Water Treatment
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• 제4권2호
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• pp.95-108
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• 2013

Metal ions exist in seawater, groundwater and industrial wastewaters. These source waters can be recycled if their concentrations are reduced. A number of processes can be applied for this purpose. Liquid-liquid extraction is one of the promising methods. In this paper, experimental results are presented on the removal of Cr(VI) using Aliquat-336, a reactive carrier, in sunflower oil (a non-toxic solvent). The performance of this new system is compared with those of kerosene (a toxic solvent). The extent of removal of Cr(VI) from samples with high and low concentrations are presented. The process was upgraded to a bench-scale module that can selectively remove about 50-90% Cr(VI) from samples of groundwater. Thus this process can produce water within the acceptable range for recycling and for use in secondary purposes such as irrigation.

• Journal of Communications and Networks
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• 제9권1호
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• pp.34-42
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• 2007

Orthogonal frequency division multiplexing (OFDM) combined with time division multiplexing (TDM), in this paper called OFDM/TDM, can overcome the high peak-to-average-power ratio (PAPR) problem of the conventional OFDM and improve the robustness against long time delays. In this paper, the bit error rate (BER) performance of OFDM/FDM in a frequency-selective Rayleigh fading. channel is evaluated by computer simulation. It is shown that the use of frequency-domain equalization based on minimum mean square error criterion (MMSE-FDE) can significantly improve the BER performance, compared to the conventional OFDM, by exploiting the channel frequency-selectivity while reducing the PAPR or improving the robustness against long time delays. It is also shown that the performance of OFDM/FDM designed to reduce the PAPR can bridge the conventional OFDM and single-carrier (SC) transmission by changing the design parameter.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 추계학술발표논문집
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• pp.97-100
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• 2008

플라스틱인 ABS와 탄산칼슘 복합소재에 사용되는 carrier resin과의 상용성 기술개발을 이용하여 무기충진재인 탄산칼슘의 최적 입도와 분산제 등의 첨가제 Recipe 확보를 통한 복합소재의 제조기술 개발하고, 이들 제조된 복합소재를 ABS에 최대 40%까지의 적용하는 기술과 함께 기계적 특성 및 충격강도, 그리고 수지 내의 무기충진에 따른 분산성을 조사하였다. 무기 충진 ABS의 시제품을 제조하여 물리적, 기계적, 열적 특성시험을 거쳐 최적의 탄산칼슘 복합소재 생산기술을 개발하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권2호
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• pp.181-184
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• 2001

The effect of topical application with 10, 20 and 30 $\mu\textrm{g}$/ml cortisone and hydrocortisone to the fifth stadium larvae of the silkworm, B. mori on fat body glycogen, protein, total lipids, phospholipids, neutral lipids and haemolymph trehalose and protein has been studied. The fat body glycogen haemolymph trehalose significantly decreased in all the treated groups except in the 10 and 20 $\mu\textrm{g}$/ml treated groups. The fat body protein increased significantly in all the cortisone and hydrocortisone treated groups except in the group treated with 10 $\mu\textrm{g}$ hydrocortisone. Whereas that of haemolymph protein significantly increased in all the groups treated with cortisone and hydrocortisone. The total lipids, phospho1ipids and neutral lipids of the fat body decreased significantly in all the groups treated with cortisone and hydrocortisone when compared with that of carrier control.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.138-140
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• 2005

Plasma arc welding(PAW) technology is a proven process that has already been adopted by other industrial fields and recently has been considered to join the tank structure of LNG carrier. The purpose of this study is to introduce PAW process for the root welding of stainless steel pipes instead of TIG welding. There are distinctive features of the PAW compared to TIG welding; higher energy density that can increase welding speed by more than twofold, and longer arc length that can be controlled to trace seam line easily because of allowable gap between workpiece and torch. However, PAW process is also very sensitive to the root gap and misalignment due to the characteristics of long and narrow arc shape. So, we have done various experiments to establish the allowable fit-up condition by changing welding parameters including arc length, with or without filler metal, groove shape, and obtained satisfactory result.