• 한국컴퓨터정보학회논문지
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• 제19권4호
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• pp.71-79
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• 2014

본 논문에서는 H-형 커플링 슬롯을 가진 광대역 이중 편파 마이크로스트립 안테나를 제안하였다. 제안된 안테나는 통신사업자들이 경쟁적으로 공공장소에 구축하고 있는 hot-spot zone과 같은 제한된 장소에서 많은 통신 단말기가 동시에 사용되면 상호 간섭이나 다중경로 페이딩에 의한 전송품질의 열화 발생을 방지할 수 있다. 설계된 안테나는 2.7GHz 이하의 주파수 대역에서 33.98%의 임피던스 대역폭($SWR{\leq}2$)과 8.58 dBi (at 2.11 GHz)의 최대 이득을 갖는 것을 측정결과를 통하여 확인하였다. 제안된 안테나는 단순한 구조로 다중 주파수 대역을 수용할 수 있으며 다양한 상업적인 적용이 가능하도록 대량생산의 장점을 갖는다.

• 한국전기전자재료학회논문지
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• 제23권5호
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• pp.408-412
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• 2010

The single-phase switched reluctance motor(SRM) generates the positive torque in the restricted section. So, it can not started by itself and the torque ripple is heavier than poly-phase. For self-starting and fixing rotating direction, the rotor should be placed at the rising inductance slope when stationary. The parking permanent magnet locates the rotor in the fixed position, which can be started by it-self. It is very simple and cost effective but has some drawbacks. It affects the rotor during the operation, so the characteristics of motor, such as a torque, speed, and ripple are changed to go bad. This paper presents the detent torque of parking magnet starting device through the finite element analysis and experiments. The finite element analysis is performed at incremental rotor positions over one detent torque cycle for any one pole. The prototype, fabricated in the previous research, is used for the experiments. The inductance, instant torque, and detent torque are calculated using the terminal voltage and phase current. Finally, the finite element analysis result and the experiment result are compared for analysis and validity.

• Advances in pediatric surgery
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• 제4권1호
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• pp.74-78
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• 1998

Early recognition and surgical treatment of Hirschsprung's disease prevents serious mortality and morbidity from enterocolitis and obstruction. Usually this disease is characterized by a single aganglionic segment of the colon extending distally to the anal margin. In surgical treatment, the surgeon performs a frozen section biopsy to confirm whether there are ganglion cells. If there are intervening ganglionic sites in aganglionic bowel, there may be confusion in diagnosis and treatment. The authors experienced one case of total colonic aganglionosis with skip area. A transverse loop colostomy was performed on a 7 day-old male baby with colon perforation due to Hirschsprung's disease. But intestinal obstruction persisted and required two more operations to find the true nature of the disease. There were aganglionic segments from the anal margin to the terminal ileum 3.7cm proximal to the ileocecal valve. The entire transverse colon and appendix were normally ganglionated.

• 대한기계학회논문집 C: 기술과 교육
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• 제2권1호
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• pp.39-46
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• 2014

이 연구에서는 탄성 플랩이 뒷전에 장착된 2차원 날개 단면의 공력 특성을 전산 해석하였다. EDISON_CFD는 날개 주위의 비압축성 난류 유동을 시뮬레이션 하기 위해 이용되었으며, MIDAS_IT는 전산 해석 결과로 얻어진 압력 하중 하에서 탄성 플랩의 변위를 구조해석 하기 위해 사용되었다. EDISON_CFD와 MIDAS_IT의 반복 계산 절차를 이용하여, 플랩의 변위가 수렴되면 해석을 종료하여, 날개 단면에 작용하는 공력을 분석하였다. 양항비의 추정 결과 일정 받음각 이내에서 플랩의 유리한 효과가 나타날 것으로 예상된다.

• 한국초전도ㆍ저온공학회논문지
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• 제6권4호
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• pp.17-21
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• 2004

The butt joint was verified to satisfy the thermal stability of the ITER magnet system through the ITER CS model coil test. Since the contact area in the butt joint is limited to the cross section of the cable, it is necessary to analyze and control the joining parameters precisely for improving the DC resistance. It is difficult to simulate the cables, which are composed of a lot of strands, as three-dimensional models using the commercial code. The random numbers were used to simulate many kinds of contact patterns of the strands on the bonding surface for calculating the bonding area and the DC resistance of the butt joint. The calculated DC resistance decreases with an increase of cable filling factor in terminal. The calculated DC resistance of a 0.9 cable filling factor is about 0.48 n-Ohm, which is about one-tenth of that in the CS model coil test when not considering the electrical contact resistance. From this difference, the electrical contact resistance between the strands and copper sheet was calculated.

• 대한화장품학회지
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• 제28권1호
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• pp.31-41
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• 2002

The production of matrix matalloproteinases(MMPs) by the UV irradiated skin fibroblast and the degradation of extracellular matrix(ECM) by these enzymes is known as one of the main reasons of photoaging. Recently, Fisher group showed that the MMP expression is mainly regulated by the mitogen-activated protein(MAP) kinas family, such as extracellular signal-regulated kinase(ERK), c-Jun amino-terminal kinase(JNK) and p38, each of which forms a signaling pathway. In this work we first examined the effect of nitric oxide (NO) on the production of MMP-1 and MMP-2 by the human dermal fibroblasts (HDFs). NO is a multifunctional messenger molecule generated from L-arginine and involved in many kinds of signaling pathway. We found that the treatment of HDF with NO donor, sodium nitroprusside (SNP) enhanced the expression of MMPs with or without UV irradiation and the treatment with nitric oxide synthase (NOS) inhibitors resulted in the significant decrease of MMPs production. From these results, we concluded that the production of MMPs by the UV irradiated HDF is regulated through the signaling pathway involving NO and cyclic GMP.

• Journal of Yeungnam Medical Science
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• 제41권2호
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• pp.128-133
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• 2024

Aortic dissection in pregnant patients results in an inpatient mortality rate of 8.6%. Owing to the pronounced mortality rate and speed at which aortic dissections progress, efficient early detection methods are crucial. Here, we highlight the importance of early chest computed tomography (CT) for differentiating aortic dissection from pulmonary embolism in pregnant patients with dyspnea. We present the unique case of a 38-year-old pregnant woman with elevated D-dimer and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, initially suspected of having a pulmonary embolism. Initial transthoracic echocardiography did not indicate aortic dissection. Surprisingly, after an emergency cesarean section, a chest CT scan revealed a DeBakey type I aortic dissection, indicating a diagnostic error. Our findings emphasize the need for early chest CT in pregnant patients with dyspnea and elevated D-dimer and NT-proBNP levels. This case report highlights the critical importance of considering both aortic dissection and pulmonary embolism in the differential diagnosis of such cases, which will inform future clinical practice.

• 한국정보통신학회논문지
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• 제18권9호
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• pp.2216-2222
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• 2014

최근 냉동컨테이너를 이용한 물동량이 계속적으로 증가하고 있는 추세에서 운송 중 냉동컨테이너의 지속적인 관리가 요구되고 있다. 하지만 현재 냉동컨테이너 모니터링은 물류 전 구간이 아닌 터미널 및 해상 운송 중 선박 내에서만 가능하며, 트럭 또는 기차를 이용하는 육상운송 구간에서는 냉동컨테이너의 모니터링이 이루어지지 않고 있다. 이는 국제해사 기구에서 권고하고 있는 PCT를 이용한 냉동컨테이너 모니터링 방법 또는 TCP/IP, RFID 통신 등을 이용한 기존 냉동컨테이너 모니터링 방법들이 별도의 통신인프라 구축이 필요하기 때문이다. 본 논문에서는 이러한 문제점들을 해결하고 육상운송 구간에서 냉동컨테이너의 모니터링뿐만 아니라 제어까지 가능한 새로운 냉동컨테이너 제어 장비를 제안하고자 한다. 제안된 장비는 모든 냉동컨테이너에 부착되어 있는 데이터 포트를 이용하여 냉동컨테이너의 정보를 수집 후 M2M 통신 기술을 이용하여 별도 통신 인프라 구축 없이 서버로 정보를 전송한다. 또한 서버에서 설정한 냉동컨테이너의 온도 설정 등 제어 정보를 수신하여 냉동컨테이너의 동작 상태를 제어 할 수 있다.

• 한국발생생물학회지:발생과생식
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• 제5권2호
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• pp.167-173
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• 2001

Ulex europaeus agglutinin I(UEA I), succinylated wheat germ agglutinin(sWGA), Griffonia simplicifolia lectin-I(GSL-I)을 이용하여 생쥐 부정소 조직내 당쇄의 분포를 조사하였다. 당쇄의 측쇄 말단의 $\alpha$-L-fucose 잔기에 특이적으로 결합하는 UEA I은 체부 및 미부 부정소를 제외한 두부 부정소 선단의 세정관 상피를 강하게 표지하였으나 관강은 중간 정도의 강도로 모두 표지되어 $\alpha$-L-fucose 잔기를 갖는 부정소 항원들은 부정소 선단부에서 주로 합성된 후 분비되는 것으로 추정된다. 이와 반대로 당쇄 말단의 $\alpha$-D-galactose 잔기에 특이적으로 결합하는 GSL-I은 두부 부정소를 제외한 체부와 미부 부정소 상피의 투명세포의 세포질과 섬모 및 기저세포를 표지하였다. 다당 사슬 및 복잡한 구조를 갖는 glycan의 당쇄의 N-acetyl-giucosamine 잔기에 특이적으로 결합하는sWCA는 부정소 부위별로 커다란 차이를 보이지 않았으나, 체부와 미부 부정소의 투명세포는 주세포에 비해 더 강하게 표지되어 sWGA 표지는 투명세포 기능분화의 표식자로 추측된다. UEA I 및 sWGA에 의한 관강의 표지 강도는 체부보다는 미부에서 약하게 관찰되어 미부 부정소 관강내에 $\alpha$-L-fucose 및 N-acetyl-glucosamine 잔기의 절단과 관련된 효소활성이 존재하는 것으로 추정된다. 요약하면 $\alpha$-L-fucose, $\alpha$-D-galactose, N-acetyl-glucosamine 잔기를 갖는 당쇄의 분포가 상피세포의 종류 및 부정소의 길이를 따라 차이를 보임을 확인하였다. 이는 정자의 성숙을 조절하는 부정소 각 절편 및 특정 절편 내 소관상피 세포의 기능적 분화를 대변하는 것으로 사료된다.

• 유통과학연구
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• 제13권10호
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• pp.123-133
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• 2015

Purpose - The Korean government has devised intermodal transportation policies and granted subsidies to shippers and logistics companies that made a conversion of transportation means through the policies. This provides support by expanding the complex uniform railroad transportation and overhauling the deteriorated railroad facilities. As for 2013, however, the freight transportation percentage of railroad was 4.5% in tons and 8.5% in ton kilometers. Meanwhile, since the 1990s, developed countries such as the U.S. and Europe have been trying to expand intermodal freight transport with a legal and institutional support to build a logistics system corresponding with social and economic environmental changes. In this study, I set out to examine the effects of the intermodal freight transport policies in the EU and the U.S., and to explore the direction of setting up a rail intermodal transport system in South Korea. Research design, data, and methodology - The paper used a qualitative research methodology through the literature review. First, was an overview of Intermodal transportation in the EU, U.S. and UN. Second, it describes the development of transport in Europe and the U.S. with particular emphasis on intermodal freight transport. Third, it explores the direction of setting up a intermodal freight transport in South Korea. The last section contains concluding remarks. Results - As for the EU, it has been promoting integration between transport and intermodal logistics network designs while utilizing ITS or ICT and supports for rail freight intermodal by giving reduction to a facilities fee or subsidizing for rail freight in order to minimize the cost of external due to freight transport. On the other hand, as for the U.S., it has been made up of an industrial-led operating project and has been promoting it to improve accessibility between intermodal hubs and cargo terminals through intermodal corridor program, and an intermodal cargo hub access corridor projects, etc. Moreover, it has tried to construct intermodal transport system using ITS or ICT and to remove Barrier. As a result, in these countries, the proportion of intermodal freight transport is going to be the second significant transport compared with rail and maritime transport. An Effective rail intermodal transport system is needed in South Korea, as seen in the case of these countries. In order to achieve this object, the following points are required to establish radical infrastructure policy; diversify investment financing measures taken under public-private partnerships, legal responsibilities, improvement of utilization of existing facilities to connect the railway terminal and truck terminal, and enhancement service competitiveness through providing cargo tracking and security information that combines the ITS and ICT. Conclusions - This study will be used as a basis for policy and support for intermodal freight transport in South Korea. In the future, it is also necessary to examine from the perspective of the shipper companies using the rail intermodal transport, ie, recognition of shipper, needed institutional supports, and transportation demand forecasting and cost-effective analysis of the railway infrastructure systems improvement.