• Clinical and Experimental Reproductive Medicine
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• v.27 no.3
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• pp.295-300
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• 2000

Objective: To report three cases of monozygotic twinning after IVF-ET transfer. Methods: Private practice in two different assisted reproductive technology clinics. Results: Three intrauterine monozygotic twin pregnancies occurred after IVF-ET. One of them was complicated by cord entanglement, another is progressing normal pregnancy without complication and the other was had a normal pregnancy without complication and delivered twin by cesarean section. Conclusion: The reported prevalence of multiple gestations in IVF-ET is a approximately 30%, and it is only 2.7% to be monozygotic twinning in IVF-ET. We report three cases of monozygotic twining after IVF-ET.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.868-872
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• 2012

유역의 유입 및 유출은 강수에 의해 발생하며 여러 가지 기후 조건과 토지 상태의 영향을 받는다. SWAT(Soil and Water Assessment Tool) 모형은 이러한 여러 가지 복잡한 기후 조건과 토지 상태를 반영하며, 장기간 입력 자료에 따른 유출량을 산출할 수 있다. 본 연구에서는 시험유역을 안동댐 유역으로 선정하였으며, SWAT 모형을 이용하여 10년(2000년 ~ 2010년) 동안의 유출량을 산정하였고 이를 안동댐의 실측 유입량과 비교 분석하였다. ArcSWAT을 이용하여 분석하였고 입력 자료는 SWAT의 분석단위인 HRU(Hydrologic Response Unit)를 산정하기 위한 정밀 토양도 및 토지피복도와 기상입력 자료인 강우 및 최고기온, 최저기온, 습도, 풍속, 일사량 등을 사용하였다. 강우관측소는 안동댐 유역의 고선, 남회룡, 도천, 미질, 석동, 석포, 석현, 의촌, 재산, 황지를 선정하였고, 일사량관측소는 안동, 대관령, 포항을 선정하였으며, 기온, 습도, 풍속관측소는 안동, 봉화, 태백, 영주를 선정하였다. 또한 기상입력자료 중 결측값은 역거리 자승법을 이용하여 보완하였다. SWAT 모형은 유출량 계산 시 여러 가지 다양한 매개변수가 사용되며, 이러한 매개변수들의 검 보정을 통하여 실제 유역의 특성과 하천 흐름특성을 반영할 수 있다. 본 연구의 시험유역인 안동댐유역은 산림과 초지가 많은 지역이기 때문에 식물에 의해 차단되는 강우에 관한 매개변수와 지하로 침투되는 강우량에 관한 매개변수 등을 보정하여 실제 유역특성을 반영하였다. 본 연구에서는 이러한 과정을 통해 안동댐 유역의 10년 동안의 일 유출량을 산정한 결과, 홍수기의 첨두유량 및 첨두시간에는 실측자료와 약간의 차이가 있었지만 전체적으로 실측자료와 매우 유사한 유출량을 산정하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.11
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• pp.1206-1212
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• 2008

This paper presents a the method for estimating the noise source contribution on the road noise of the vehicle in a multiple input system where the input sources may be coherent with each other. By coherence function method, it is found that the biggest part of the noise source in the road noise is generated by structural vibration on the mechanical-acoustic transfer functions of vehicles. This analysis is modeled as four input/single output system because the noise is generated with four wheels that mechanism of the road noise is very complicated. The coherence function method is proved to be useful tool for identifying of noise source. The overall levels of the interior noise be coherence function method are compared with those measured and calculated by the frequency response function approach using mechanical excitation test. The experimental results have shown a good agreement with the results calculated by the coherence function method when the input sources are coherent strongly each other. The estimation of the road noise indicates that significant coherent can be achieved in the vehicle interior noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.830-833
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• 2004

An indoor package air-conditioner (PAC) has complex noise sources such as motor noise and fluid noise caused by the fan motor, heat transfer and shroud. Sound intensity techniques and ODS(Operational deflection shape) techniques are applied to identify the noise characteristics of an indoor air-conditioner's cabinet. The sound intensity is used to visualize the noise source locations. and the ODS to visualize the vibration pattern and to obtain the dynamic characteristics of the noise source. Acoustic intensity and operational deflection distribution are obtained in space domains as well as frequency domains. Using the visual information of source locations and its dynamic characteristics, the damping patch is applied to reduce structure borne noise in the cabinet. As a result, the noise emitted by the cabinet is reduced by 5dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.495-499
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• 2000

The booming noise of a vehicle is usually caused by the vibration of the vehicle's body transmitted from the engine through the mounting system. Thus the engine mounting system must be cautiously designed to reduce the noise. Vector synthesis analysis is performed to predict the booming noise when the characteristic of the engine mounting system is changed., i.e., when magnitudes and phases of vibratory forces after the mounts are altered. To effectively use the method, the concept of 'effectiveness' is introduced to identify the contributions of each vibration sources and transmission paths to interior noise. When the magnitudes and phases of the forces due to the engine vibration are changed, the synthesized interior booming noise level is predicted by the vector synthesis diagram. Thus, the optimum characteristics of the forces are obtained through the simulations of the vector synthesis analysis. It is shown that the vector synthesis method can be used to obtain the optimum design characteristic of the mounting system to control the interior booming noise of a vehicle.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.318-324
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• 2009

1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has recently been synthesized and characterized to have an anti-inflammatory activity through the inhibition of the production of nitric oxide. In the present study, adverse effects of FPP-3 on hepatic functions were determined in female BALB/c mice. When mice were administered with FPP-3 at 125, 250 or 500 mg/kg for 7 consecutive days orally, FPP-3 significantly increased absolute and relative weights of liver with a dose-dependent manner. In addition, FPP-3 administration dramatically increased the hepatotoxicity parameters in serum at 500 mg/kg, in association of hepatic necrosis. FPP-3 significantly induced several phase I enzyme activities. To elucidate the possible mechanism(s) involved in FPP-3 induced hepatotoxicity, we investigated the hepatic activities of free radical generating and scavenging enzymes and the level of hepatic lipid peroxidation. FPP-3 treatment significantly elevated the hepatic lipid peroxidation, measured as the thiobarbituric acid-reactive substance, and the activity of superoxide dismutase. Taken together, the present data indicated that reactive oxygen species might be involved in FPP-3-induced hepatotoxicity.

• The KIPS Transactions:PartA
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• v.14A no.4
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• pp.227-234
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• 2007

In the virtual prototyping environment, we can simulate details of a target model using many components and libraries provided in advance on a computer. The real prototyping environment provides the test simulation environment as a real product, but we can't do a detailed simulation of a real product in the virtual prototyping environment, and we can't do various simulations in the real prototyping environment. So, we made a integrated prototyping environment for linkage of the two types of prototyping environments. Also, in this paper, we developed the integrated prototyping environment based on objects. By this kind of embedded system development environment, we can have the advantages as reuse, flexibility, scalability, and more convenient of product making.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.6
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• pp.583-591
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• 2012

Plate heat exchangers have been widely used in many industrial applications because of their compactness and high efficiency. Even though plate heat exchangers have been investigated extensively, studies on the effects of geometric parameters other than the chevron angle are very limited in the open literature. In this study, the effects of the chevron angle, corrugation length, corrugation depth, and the number of plates on the heat transfer and pressure drop characteristics of plate heat exchangers were investigated experimentally. Based on the experimental results, empirical correlations were proposed. More than 95% of the predictions made based on the correlations had relative deviations of less than ${\pm}10%$ when compared with the measured data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.805-814
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• 2011

Aluminum plate-fin heat exchangers (ALPHEs) are widely used in petroleum and gas-treated processes. The performance of the ALPHE is strongly dependent on the distribution characteristics of the header and the distributors of each fluid. In this paper, we define the aspect ratio in the side-entry type distributor and analyze the distribution characteristics using CFD-based numerical methods. The phenomena of velocity deviation and distribution with the aspect ratio and the inlet Reynolds number were analyzed by applying relative and absolute maldistribution parameters, and an optimum aspect ratio with the inlet Reynolds number was presented.

• Journal of Korean Foot and Ankle Society
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• v.9 no.2
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• pp.167-172
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• 2005

Purpose: We report our results of arthroscopic treatment of symptomatic avulsion fracture of the malleolus in chronic ankle pain, and also analyzed the clinical and radiological features for evaluating the good candidate for arthroscopic treatment. Materials and Methods: Fourteen patients who were diagnosed with intra-articular avulsion fractures of the malleolus received arthroscopic surgery and were followed up for at least a year. The clinical and radiological characters including MRI and arthroscopic findings were reviewed. Clinical assessments were done according to the AOFAS score system. Results: There was a history of inversion type of the injury in most cases and local tenderness of lesion site was a unique. MRI study showed thickened anterior talofibular ligament (ATFL) in 8 cases (57%) and discontinued ATFL in 3 cases (21%). Enhanced signal surrounding soft tissue corresponding to synovial inflammation and impingement was found in 12 cases (86%). Preoperative score of all patients were $74.0{\pm}5.5$, which improved to $89.3{\pm}6.7$ at the follow-up after the treatment (P<0.001). Conclusion: Most patients had history of injury and localized tenderness in the area coinciding with radiological findings. Thickened ATFL and contrast enhancement around the ossicle were frequently found. Symptomatic avulsion fractures of the malleolus associated with the clinical and radiological findings above could be a good candidate for arthroscopic treatment.