• Journal of Korean Neurosurgical Society
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• 제56권4호
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• pp.344-347
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• 2014

Stent thrombosis is a major limitation of stent-assisted coiling, which is an effective method for treating wide-necked aneurysms. Although early in-stent thrombosis has been reported, very late stent thrombosis (VLST) (>1 year) has not been reported following implantation of a single self-expandable stent designed for coiling. Herein, the authors present a case of VLST that occurred 14 months after single stent implantation in a large paraclinoid aneurysm with an ultra-wide neck involving the parent artery circumferentially. This case indicates the need for establishing guidelines regarding the optimal duration of prophylactic antiplatelet therapy following stent-assisted coiling, which remains undefined in the neuroendovascular field.

• Journal of information and communication convergence engineering
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• 제8권6호
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• pp.640-644
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• 2010

When we talk with hands-free in a car or noisy lobby, the performance of the echo canceller degrade because background noise added to echo caused by the distance from mouth to microphone is relatively long. It gives a reason for necessity of noise-robust and high convergence speed adaptive algorithm. And if acoustic echo canceller operated not perfectly, residual signal going through the echo canceller to far-end speaker remains residual echo, which degrade quality of talk. To solve this problem, post-processing needed to remove residual echo ones more. In this paper, we propose a new acoustic echo canceller, which has noise robust and high convergence speed, linked with linear predictor as a post-processor. By computer simulation, it is confirmed that the proposed algorithm shows better performance from acoustic interference cancellation (AIC) viewpoint.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.171-174
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• 2008

본 논문에서는 2단 인버터를 사용한 고성능 연계형 인버터의 구성을 제안하였다. 2단 인버터에서 하나의 인버터는 연계전압과 동일한 전압을 생성하고, 다른 하나의 인버터는 연계 전압에 포함되어 있는 고조파 성분을 제거하기 위한 전압을 생성한다. 본 논문의 제안된 구조는 PSIM 시뮬레이션으로 통해 확인하였으며, 그 결과 기본파(60Hz) 전압만 남게 되어 양질의 정현적인 전류를 연계 할 수 있음을 보였다.

• 생물정신의학
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• 제8권2호
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• pp.233-238
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• 2001

The routine interictal electroencephalogram(EEG) continues to play an important role in the diagnosis and treatment of epilepsy. The clinical investigation of brain disease in the last decade has been marked by dramatic advances in functional imaging, magnetic resonance scanning and digitized EEG. Epilepsy is a disorder of electrical hyperirritability of cerebral cortex and the interictal EEG remains the most convenient means available to demonstrate cortical hyperirritability. The sensitivity and specificity of the EEG in the diagnosis of epilepsy have been disputed. In this review, the type of EEG findings in epilepsy are reviewed and the sensitivity and specificity of interictal epileptiform discharge are discussed. And also the role of EEG in various clinical situations are summarized.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.95-97
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• 2012

Recycled aggregate (RA) produced from demolished concrete waste can bring about several problems on concrete performance, when it is used as aggregate for new concrete. Because RA generally has lower quality than natural aggregate due to the residual cement paste attached on RA and various impurities. It is also very difficult to ensure that the quality of RA remains consistent, because generally RA is produced variously. Thus, in concrete recycling, it is extremely important to estimate the risk of the impurities which could affect performances of recycled aggregate concrete (RAC) focusing on the material flow of concrete waste and its recycling. This study suggests an evaluation result to expect the possibility of impurity mixing in RA production procedure. and suggests a risk evaluation model to expect the changes of RAC performances based on conventional data in Japan.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1640-1643
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• 2002

Image sticking, the phenomenon that the previously displayed pattern still remains after the image is changed into different image, is one of the most serious problem in realizing high picture quality. In this paper, we tried characterizing this undesirable feature in terms of the luminance and the intial firing voltage at ramp up time in reset period. It was found that the cell located at the boundary of previous image pattern show low firing voltage and high background luminance. And the results show that the degree of the image sticking is severely affected by discharge duration and the length of the sustain period.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 금형가공 심포지엄
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• pp.144-147
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• 2002

In this study, springback analysis of side rear member is carried out. Side rear member is one of the parts which shows severe springback problems. Forming, trimming, flanging and springback stages can be analyzed successively. From forming analysis, we identified the possible spots in which tearing may occur and can prevent failure. In springback analysis we used the boundary conditions same as applied to the blank on the checker so that the computational result can be compared with experimental one. Form .the comparison, springback analysis can yield relatively good results in a qualitative sense. However, in order to get good deformation result quantitatively, there still remains unsettled tasks in the forming analysis with very small die radius. It is found that we have to develop the element with better bending characteristics and precise contact treatment.

• Molecules and Cells
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• 제38권5호
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• pp.390-395
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• 2015

Degradation of chlorophyll (Chl) by Chl catabolic enzymes (CCEs) causes the loss of green color that typically occurs during senescence of leaves. In addition to CCEs, STAYGREEN1 (SGR1) functions as a key regulator of Chl degradation. Although sgr1 mutants in many plant species exhibit a staygreen phenotype, the biochemical function of the SGR1 protein remains elusive. Many recent studies have examined the physiological and molecular roles of SGR1 and its homologs (SGR2 and SGR-LIKE) in Chl metabolism, finding that these proteins have different roles in different species. In this review, we summarize the recent studies on SGR and discuss the most likely functions of SGR homologs.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.167-175
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• 2014

Chemotherapy has long been considered as one of useful strategies for cancer treatment. It is primarily based on the apoptosis that can selectively kill cancer cells. However, cancer cells can progressively develop an acquired resistance to apoptotic cell death, rendering refractory to chemo- and radiotherapies. Although the mechanism by which cells attained resistance to drug remains to be clarified, it might be caused by either pumping out of them or interfering with apoptotic signal cascades in response to cancer drugs. In case that cancer cells are defective in some part of apoptotic machinery by repeated exposure to anticancer drugs, alternative cell death mechanistically distinct from apoptosis could be adopted to remove cancer cells refractory to apoptosis-inducing agents. This review will mainly deal with harnessing of necrotic cell death, specifically, programmed necrosis and practical uses. Here, we begin with various defects of apoptotic death machinery in cancer cells, and then provide new perspective on programmed necrosis as an alternative anticancer approach.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2000년도 춘계 학술발표회 논문집
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• pp.43-50
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• 2000

The flow field of a 1 Ton/Day entrained-flow gasifier constructed in KIER was numerical simulate in this paper. The standard $k-{\varepsilon}$ turbulence model and simple procedure was used with the Primitive-Variable methods during computation. In order to find the influence factors of the flow field which may have great effects on coal gasification process inside gasifier, difference geometry parameters at various operating conditions were studied by simulation methods. The calculation results show that the basic shape of the flow field is still parabolic even the oxygen gas is injected from the off-axis position. There exist an obvious external recirculation zone with a length less than 1.0m and a small internal recirculation region nears the inlet part. The flow field inside the new gasifier is nearly similar as that of the old 0.5T/D gasifier at same position if the design of burner remains unchanged.