• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.413-420
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• 2006

The construction of a submerged breakwater has become increasing due to their multiple effects on the coastal zone. Recently, marker rocks have been installed on the submerged breakwater to indicate its position to the vessels instead of buoy systems, since a buoy is not only improper for the ocean view, but also its mooring system may be damaged by the impulsive wave force caused by wave breaking on the breakwater. The accurate estimation of wave forces on such rocks is deemed necessary for their stability design. In this study, the characteristics of irregular wave forces acting on a marker rock, which was installed on a submerged breakwater, was investigated on the basis of laboratory experiments. It was revealed that the dimensionless highest one-third wave force tends to decrease with increasing the installation distance of a marker rock from the leading crown edge of a submerged breakwater. Also, the drag and inertia coefficients for irregular wave forces, which were obtained using the Morison equation, were investigated in relation to K.C. number.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.8
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• pp.372-377
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• 2008

Multiclass cancer classification has been actively investigated based on gene expression profiles, where it determines the type of cancer by analyzing the large amount of gene expression data collected by the DNA microarray technology. Since gene expression data include many genes not related to a target cancer, it is required to select informative genes in order to obtain highly accurate classification. Conventional rank-based gene selection methods often use ideal marker genes basically devised for binary classification, so it is difficult to directly apply them to multiclass classification. In this paper, we propose a novel method for multiclass gene selection, which does not use ideal marker genes but directly analyzes the distribution of gene expression. It measures the class-discriminability by discretizing gene expression levels into several regions and analyzing the frequency of training samples for each region, and then classifies samples by using the naive Bayes classifier. We have demonstrated the usefulness of the proposed method for various representative benchmark datasets of multiclass cancer classification.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.769-770
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• 2009

본 논문에서는 이상 표식 유전자를 사용하는 기존 분석방법과 달리, 두 유전자 사이의 관계를 측정하여 정상 클래스와 암 클래스에서의 상관관계가 변화된 정도를 분석하여 차이가 두드러지는 유전자 쌍(gene pair)을 질병 분류자(classifier)로 선택하는 방법을 제시한다. 제안한 암 분류 방법의 실험 결과, 소수의 분류자를 선택하여 높은 정확도로 암을 분류함으로써 그 유용성을 검증하였다.

• The Korean Journal of Zoology
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• v.21 no.2
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• pp.59-66
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• 1978

A dispersal experiment on Culex tritaeniorhynchus females by a mark-release-recapture method was carried out at Pohgang city, Korea, in Augst 1974. The results are summarized as follows: 1. Of 23,115 females of C. tritaeniorhynchus released, 120 females were recaptured, giving 0.519% recapture rate and 0.00208 recovery ration. 2. Dispersal rates from the release site were 77.5% in 0-2km, 11.7% in 4-6 km and 5.8% in 6-8km. 3. C. tritaeniorhynchus females flew 7.5km in one day. The average of the daily mean distances was 1.55km, and it showed that the dispersal distance did not correlate with days after release.

• Journal of Ocean Engineering and Technology
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• v.16 no.6
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• pp.7-17
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• 2002

Recently, artificial rocks, instead of buoys, have been placed on the submerged breakwater to indicate its location. The accurate estimation of wave forces on these rocks is deemed necessary for their stability design. Characteristics of the wave force, however, are expected . to be very complicated because of the occurrence of breaking or post-breaking waves. In this regard, wave forces exerted on an artificial rock have been investigated in this paper. The maximum wave force has been found to strongly dependent on the location and shape of the artificial rock that is placed on the submerged breakwater. The plunging breaker occurs near the loading cram edge of a submerged breakwater, which cause impulsive breaking wave force on the rock. Using the Morison equation, with the velocity and acceleration at the front face of the artificial rock and varying water surface level, it is possible to estimate wave forces, even impulsive breaking wave forces, that are acting on the rock installed on a submerged breakwater. The vertical wave force is also found to depend, significantly, on the buoyant force.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.559-561
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• 2002

서포트 벡터 머신은 얼굴인식이나 문자인식과 같은 다양한 패턴인식 문제에서 좋은 성능을 보여준다. 그러나 이러한 문제는 Quadratic Programming(QP) 문제에 관하여 몇 가지 단점을 가지고 있다. 일반적으로 대용량의 QP 문제를 해결하기 위해 많은 계산비용이 요구되며, QP 기반 시스템을 효과적으로 구현하는 것이 쉽지 않은 문제이다. 또한 대규모 데이터의 처리 시에는 입출력을 맞추기 또한 쉽지 않은 단점이 있다. 본 논문에서는 위의 단점을 극복하기 위하여 단일부류 문제를 최소제곱 서포트 벡터 머신을 기반으로 하여 해결하였다. 제안한 방법은 QP 문제를 해결하는 과정이 없이 단일부류 문제를 표현하여 최소제곱 방법을 이용하는 알고리즘이다. 제안된 방법으로 쉽고, 계산 비용을 줄이는 결과를 얻었다. 또한 서포트 벡터 영역 표식자에 확장 적용하여 선형방정식으로 구현하여, 문제를 해결하였다. 제안된 방법의 효율성을 입증하기 위하여 패턴인식 분야 중에 얼굴 인증 방법과 바이오인포매틱스 분야 중에 전립선 암 분류 문제에 적용하였다. 우리의 실험결과는 적합한 성능과 좋은 Equal Error Rate(EER)를 보여준다. 제안된 방법은 알 수 없는 물체의 분류 방법의 효율성을 증대시켰고, 실시간 응용분야에 직접적으로 적용될 수 있을 것으로 기대 된다.

• Journal of Life Science
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• v.31 no.10
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• pp.873-884
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• 2021

The purpose of present study is to investigate the role of artesunate (ART) in enhancing anticancer effect of nonsteroidal anti-inflammatory drug (NSAID) on human cancer cells, and we elucidate a possible molecular mechanism of this combination effect. We showed that the combined effect of ART with NSAID such as celecoxib (CCB) or dimethyl-CCB (DMC) in various type of human cancer cells. After ART treatment, the expression of p62, nuclear factor erythroid 2-like 2 (NRF2) and cancer stemness (CS)-related proteins including CD44, CD133, aldehyde dehydrogenase 1 (ALDH1), octamer-binding transcription factor 4 (Oct4), mutated p53 (mutp53) and c-Myc was down-regulated. ART induced autophagy as reduction of the autophagy receptor p62, which was associated with up-regulation of activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP), and simultaneous down-regulation of NRF2 and CS-related proteins was occurred in the human cancer cells. These results indicate a possibility that ART activates autophagy through ATF4-CHOP cascade leading to down-regulation of CS-related proteins and subsequently eradicated cancer stem cells. In addition, co-treatment with ART and imatinib was more effective than either drug alone on growth inhibition and apoptosis induction of cancer cells. In conclusion, induction of autophagy-dependent cell death by ART might play a critical role in mediating the synergistic effect of drug combination (ART/NSAID and ART/imatinib). Therefore, ART could be a promising candidate as a chemosensitizer to enhance the anticancer effects of NSAID and imatinib.

• Korean Journal of Human Ecology
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• v.22 no.1
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• pp.181-188
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• 2013

노인에게서 두드러지게 나타나고 있는 저근육형 비만은 근육감소를 동반한 체지방의 증가로 신체상의 뚜렷한 체성분의 변화를 야기 시킨다. 이때 골감소증을 동반하여 신체기능의 감소 및 골절장애 그리고 대사성 관련 질환의 위험도가 올라가는 것으로 보고되고 있다. 노화로 인한 체성분의 변화는 단순한 저근육형일 경우와 비만일 때 보다 급격히 증가된 복부내장 지방조직에서 분비되는 염증성 사이토카인, C-반응성 단백질(CRP), 인터루킨(IL)-6, IL-8 및 종양 괴사 인자(TNF-${\alpha}$)들이 단백질 대사를 저해하여 근육량의 감소를 더욱 촉진시키며, 염증관련 대사질환의 유병률에 중요한 요인이다. 본 연구에서는 DNA 메틸화가 당뇨병, 심혈관질환, 암과 같은 만성염증성 질환에 관계하고 있다는 최근 연구 결과를 기초로 하여 항염증 영양소와 생리활성을 갖는 식품인자들의 충분한 섭취가 염증조절에 중요하게 기여할 것으로 생각되며, 또한 염증성 질환의 주요 표식자인 DNA 메틸화와 히스톤 변형을 유발하는 효소의 활성 또는 비 암호화된 RNA의 발현을 조절함으로써 근육량 증가와 체지방 감소에 중요한 역할을 하는 것을 살펴보았다. 따라서 최근 새롭게 인식되는 후생유전학적 연구의 중심에 있는 항염증 영양소의 효과와 체성분 변화와의 긍정적 관계를 중심으로 저근육형 비만의 예방 및 인구고령화에 건강한 노화를 위한 효과적인 방법을 제시하였다.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.679-686
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• 2003

Purpose : Ataxia telangiectasia mutated(ATM) is involved in DNA damage responses at different cell cycle checkpoints, and signalling pathways associated with regulation of apoptosis in response to ionizing radiation(IR). However, the signaling pathway that underlies IR-induced apoptosis in ATM cells has remained unknown. The purpose of this study was, therefore, to investigate the apoptotic pathway that underlies IR-induced apoptosis in a CT-26 cells expressing dominant negative ATM (DN-ATM). Methods : We generated a replication-deficient recombinant adenovirus encoding the DN-ATM(Ad/DN-ATM) or control adenovirus encoding no transgene(Ad/GFP) and infected adenovirus to CT-26 cells. After infection, we examined apoptosis and apoptotic pathway by [$^3H$]-thymidine assay, DNA fragmentation, and Western immunoblot analysis. Results : DN-ATM gene served as the creation of AT phenotype in a CT-26 cells as revealed by decreased cell proliferations following IR. In addition, IR-induced apoptosis was regulated through the reduced levels of the anti-apoptotic protein Bcl-2, the increased levels of the apoptotic protein Bax, and the activation of caspase-9, caspase-3, and PARP. Conclusion : These results indicate that the pathway of IR-induced apoptosis in CT-26 cells expressing DN-ATM is mediated by mitochondrial signaling pathway involving the activation of caspase 9, caspase 3, and PARP.

• Journal of Life Science
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• v.30 no.6
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• pp.563-569
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• 2020

Oncoplastic surgery (OPS) combines oncologically safe tumor resection with aesthetically satisfying reconstruction of defects using established plastic surgery techniques. OPS is characterized by initial excision as extensive as is beneficial for oncological safety, and, once sufficient resection is complete, displacement or replacement techniques are selected based on remnant volume. The size of the lesion and the individual patient are important factors when considering the appropriate approach, and when pre-operative imaging, including MRI, is used to determine the technique, the complete removal of cancer cells by permanent pathology is essential. A frozen section is used during the operation to reduce the reoperation rate, but it is difficult to cover the entire margin surface theoretically and even harder in practice. A recent report about adequate margins has empowered OPS in its oncological safety. Considering the patients to whom each modality could be applied, basic breast volume is an important factor, and this is influenced by ethnic differences. In Europe or the US, for example, the average breast size is 36D (600 ㎤) and reduction mammoplasty is predominantly used. However, the average size of patients in our institution is 33A (300 ㎤), and so quite different approaches are selected in most cases. New techniques involving radiofrequency and fluorescence have been proposed as safe and easily accessible ways of reducing complications.