• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.588-591
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• 2000

Sphingoliped 대사의 율속효소인 serine palmitoyl transferase(SPT)와 acid ceramidase의 연구를 위하여 인간의 SPTII 유전자와 acid ceramidase 유전자의 5‘-upstream region을 얻었다. 사람의 대장암세포인 HT29 cell로부터 genomic DNA를 얻고 GenomeWalker kit를 이용하였으며 2690bp의 SPTII promoter와 2028bp 및 1034bp의 acid ceramidase promoter의 fragment들을 얻을 수 있었다. 이들 DNA 조각들을 T7Blue vector에 subcloning하여 sequencing하였으며 이들이 사람의 SPTII 및 acid ceramidase gene의 5’-upstream region임을 확인하였다. 동물세포에서의 promoter activity를 측정하기위하여 firefly luciferase를 reporter gene으로 하는 pGL2-enhancer vector와 pGL2-basic vector에 subcloning하였으며 pRL-TK vctor와 함께 HT29 cell 및 HepG2 cell에 cotransfection 시킨 후 luciferaseg활성을 측정한 결과 같은 양의 DNA로는 사람의 SPTII promoter와 acid ceramidase promoter는 pRL-TK에 비하여 transfection efficiency가 아주 낮았으며 promoter 연구를 위하여는 pRL-TK vector의 양을 1/100으로 줄이는 것이 적당하였으며 HT29 cell보다는 HepG2 cell에 더 높은 발현율을 보였다.

• 대한수학회지
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• 제35권4호
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• pp.891-901
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• 1998

We give a definition of the vector-valued index for Z-actions extending the numerical index in [9] and prove the extension theorem for Z-actions for showing basic properties of the vector-valued index.

• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1735-1740
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• 2008

Clone PERV-C (A3) env was isolated from the genomic DNA of domestic pig (Sus scrofa domesticus) in Korea to investigate the molecular properties of PERV-C. The nucleic acid homologies between the PERV-MSL (type C) reference and the PERV-C(A3) clone was 99% for env, but a single base pair deletion was found in the transmembrane (TM) region of the env open reading frame. To examine the functional characteristics of truncated PERV-C env, we constructed a replication-incompetent retroviral vector by replacing the env gene of the pCL-Eco retrovirus vector with PERV-C env. A retroviral vector bearing PERV-C/A chimeric envelopes was also created to complement the TM defect. Our results indicated that truncated PERV-C env was not infectious in human cells as expected. Interestingly, however, the vector with the PERV-C/A envelope was able to infect 293 cells. This observation suggests that recombination within PERV-C TM could render PERV-C infectious in humans. To further characterize PERV-C/A envelopes, we constructed an infectious molecular clone by using a PCR-based technique. This infectious molecular clone will be useful to examine more specific regions that are critical for human cell tropism.

• IEIE Transactions on Smart Processing and Computing
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• 제4권1호
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• pp.16-21
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• 2015

Most video services are transmitted in wireless networks. In a network environment, a packet of video is likely to be lost during transmission. For this reason, numerous error concealment (EC) algorithms have been proposed to combat channel errors. On the other hand, most existing algorithms cannot conceal the whole missing frame effectively. To resolve this problem, this paper proposes a new Adaptive Prediction Unit-based Motion Vector Extrapolation (APMVE) algorithm to restore the entire missing frame encoded by High Efficiency Video Coding (HEVC). In each missing HEVC frame, it uses the prediction unit (PU) information of the previous frame to adaptively decide the size of a basic unit for error concealment and to provide a more accurate estimation for the motion vector in that basic unit than can be achieved by any other conventional method. The simulation results showed that it is highly effective and significantly outperforms other existing frame recovery methods in terms of both objective and subjective quality.

• Communications for Statistical Applications and Methods
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• 제10권3호
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• pp.873-878
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• 2003

LS-SVM(Least-Squares Support Vector Machine) has been used as a promising method for regression as well as classification. Suykens et al.(2000) used only the magnitude of residuals to obtain SVs(Support Vectors). Suykens' method behaves well for homogeneous model. But in a heteroscedastic model, the method shows a poor behavior. The present paper proposes a new method to get SVs. The proposed method uses the variance of noise as well as the magnitude of residuals to obtain support vectors. Through the simulation study we justified excellence of our proposed method.

• Journal of Information Processing Systems
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• 제9권3호
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• pp.395-404
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• 2013

In order to classify a web page as being benign or malicious, we designed 14 basic and 16 extended features. The basic features that we implemented were selected to represent the essential characteristics of a web page. The system heuristically combines two basic features into one extended feature in order to effectively distinguish benign and malicious pages. The support vector machine can be trained to successfully classify pages by using these features. Because more and more malicious web pages are appearing, and they change so rapidly, classifiers that are trained by old data may misclassify some new pages. To overcome this problem, we selected an adaptive support vector machine (aSVM) as a classifier. The aSVM can learn training data and can quickly learn additional training data based on the support vectors it obtained during its previous learning session. Experimental results verified that the aSVM can classify malicious web pages adaptively.

• 방송공학회논문지
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• 제14권6호
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• pp.807-810
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• 2009

본 논문은 실감 원격회의 시스템을 위한 실시간 영상기반 재조명 기술을 제안한다. 구체적으로 원격 사용자의 영상을 미리 캡처된 환경맵을 이용하여 재조명해서 사용자가 같은 공간에 있도록 느끼게 한다. 일반적으로 재조명 수행에 사용자 모델의 정교한 기하학적 모델정보를 도출하는 것이 고품질 재조명 영상을 도출하는데 큰 영향을 준다. 본 논문에서는 두 개의 방향성 조명을 사용하여 실시간으로 사용자 모델정보를 도출하는데 중점을 두었다. 도출된 모델정보와 환경맵의 조명정보를 이용하여 재조명 연산을 수행하고, 그래픽 하드웨어를 사용하여 고속으로 연산을 수행한다. 본 논문에서는 두 개의 방향성조명과 동기화된 카메라를 순차적으로 점등하여 사용자 표면의 반사율 맵을 도출한다. 그리고 빛이 반사할 때 표면에서 입사각과 반사각이 동일한 특징에 근거하여 반사맵 영상의 밝기가 밝을수록 사용자 표면의 법선벡터가 조명과 카메라간의 사잇각이 될 확률이 높아진다. 그래서 양방향의 반사율 값과 사잇각 두 개의 파라미터를 곱하여 표면의 법선벡터를 완성한다. 본 연구의 결과를 이용하면 영상기반 재조명 연구의 실제적이고도 폭넓은 적용이 가능할 것으로 사료되며 고화질의 콘텐츠 양산에도 기여할 것으로 사료된다.

• 대한수학회논문집
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• 제32권1호
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• pp.107-118
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• 2017

In this paper we study CR-submanifolds of maximal CR-dimension by investigating extrinsic behaviors of integral curves of characteristic vector field on them. Also we consider the notion of ruled CR-submanifold of maximal CR-dimension which is a generalization of that of ruled real hypersurface and find some characterizations of ruled CR-submanifold of maximal CR-dimension concerning extrinsic shapes of integral curves of the characteristic vector field and those of CR-Frenet curves.

• 호남수학학술지
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• 제26권2호
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• pp.219-236
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• 2004

In this paper, the problem of estimating a p-variate ($p{\geq}4$) normal mean vector is considered in a decision-theoretic setup. Using a simple property of the noncentral chi-square distribution, a sequence of smooth estimators dominating the Lindley type estimator has been produced and each improved estimator is better than previous one.

• Kyungpook Mathematical Journal
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• 제62권2호
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• pp.333-345
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• 2022

We study *-Ricci solitons on non-cosymplectic (κ, µ)-acs (almost cosymplectic) manifolds M. We find *-solitons that are steady, and such that both the scalar curvature and the divergence of the potential field is negative. Further, we study concurrent, concircular, torse forming and torqued vector fields on M admitting Ricci and *-Ricci solitons. Also, we provide some examples.