• 제목/요약/키워드: k-opt

검색결과 193건 처리시간 0.033초

Molecular gas properties under ICM pressure : A Case study of NGC4402

  • 한유진;정애리
    • 천문학회보
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    • 제36권2호
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    • pp.117.2-117.2
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    • 2011
  • We probe 12CO J=2-1 and 13CO J=1-0 properties of a Virgo disk galaxy, NGC 4402 which is located near the cluster center. Our goal is to study the impact of intra cluster medium (ICM) on the molecular gas of a galaxy in the cluster environment. It has been believed that cluster galaxies are deficient in atomic hydrogen gas (HI gas) compared to their field counterparts and now there is much evidence that low density ISM can be easily removed by ram pressure caused by ICM wind. Meanwhile, no significant molecular gas deficiency of the cluster galaxy population has been found yet they show overall lower star formation rate than galaxies in the field, and it is still controversy whether dense ISM can be also stripped by the ICM wind or not. NGC 4402 with truncated HI disk($D_{HI}/D_{opt}$ ~ 0.75 and only 36%of HI gas compare to field galaxies of a similar size) and a disturbed gas morphology, appears to have strong ongoing ram pressure. Using high resolution 12 and 13CO data of NGC 4402 from a Sub Millimeter Array (SMA), we probe the molecular gas properties under strong ICM pressure. We discuss how its star formation activity and hence the global color of NGC4402 would be changed in the future.

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A 95% accurate EEG-connectome Processor for a Mental Health Monitoring System

  • Kim, Hyunki;Song, Kiseok;Roh, Taehwan;Yoo, Hoi-Jun
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권4호
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    • pp.436-442
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    • 2016
  • An electroencephalogram (EEG)-connectome processor to monitor and diagnose mental health is proposed. From 19-channel EEG signals, the proposed processor determines whether the mental state is healthy or unhealthy by extracting significant features from EEG signals and classifying them. Connectome approach is adopted for the best diagnosis accuracy, and synchronization likelihood (SL) is chosen as the connectome feature. Before computing SL, reconstruction optimizer (ReOpt) block compensates some parameters, resulting in improved accuracy. During SL calculation, a sparse matrix inscription (SMI) scheme is proposed to reduce the memory size to 1/24. From the calculated SL information, a small world feature extractor (SWFE) reduces the memory size to 1/29. Finally, using SLs or small word features, radial basis function (RBF) kernel-based support vector machine (SVM) diagnoses user's mental health condition. For RBF kernels, look-up-tables (LUTs) are used to replace the floating-point operations, decreasing the required operation by 54%. Consequently, The EEG-connectome processor improves the diagnosis accuracy from 89% to 95% in Alzheimer's disease case. The proposed processor occupies $3.8mm^2$ and consumes 1.71 mW with $0.18{\mu}m$ CMOS technology.

직렬시스템의 신뢰도 최적 설계를 위한 Hybrid 병렬 유전자 알고리즘 해법 (A Hybrid Parallel Genetic Algorithm for Reliability Optimal Design of a Series System)

  • 김기태;전건욱
    • 산업경영시스템학회지
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    • 제33권2호
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    • pp.48-55
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    • 2010
  • Reliability has been considered as a one of the major design measures in various industrial and military systems. The main objective is to suggest a mathematical programming model and a hybrid parallel genetic algorithm(HPGA) for the problem that determines the optimal component reliability to maximize the system reliability under cost constraint in this study. Reliability optimization problem has been known as a NP-hard problem and normally formulated as a mixed binary integer programming model. Component structure, reliability, and cost were computed by using HPGA and compared with the results of existing meta-heuristic such as Ant Colony Optimization(ACO), Simulated Annealing(SA), Tabu Search(TS) and Reoptimization Procedure. The global optimal solutions of each problem are obtained by using CPLEX 11.1. The results of suggested algorithm give the same or better solutions than existing algorithms, because the suggested algorithm could paratactically evolved by operating several sub-populations and improving solution through swap and 2-opt processes.

Co-rotational 이론 기반 비선형 삼각평면 유한요소의 개발 (Development of Nonlinear Triangular Planar Element Based on Co-rotational Framework)

  • 조해성;신상준
    • 한국전산구조공학회논문집
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    • 제28권5호
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    • pp.485-490
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    • 2015
  • 구조의 기하학적 비선형해석을 위해 대표적으로 Total Lagrangian, Updated Lagrangian 정식화 기법이 있다. 이러한 고전적인 정식화 과정은 요소의 변형률을 가정하는 방법에 따라 그리고 요소의 절점 수에 따라 추가의 수학적 정식화 과정이 요구된다. 하지만 비교적 최근에 정립된 Co-roational(CR) 이론은 기 존재하는 보, 판, 쉘 요소에 독립적으로 요소 절점자유도에 따라 일정하게 적용하여 대변위, 작은 변형률을 갖는 구조의 기하비선형 해석을 가능케 한다. 본 논문에서는 회전자유도를 갖는 삼각평면요소에 대한 CR 기법을 정식화하였고 동적해석으로 확장하여 이를 상용프로그램과 검증하였다. 해석에 사용한 삼각평면요소는 OPtimal Triangular(OPT) 평면요소이다.

Bovine Ordorant Binding Protein에 대한 Tetrahydropyrane 및 Tetrahydrofurane 유도체들의 결합 친화력 상수에 관한 2D-QSAR 분석과 고활성 분자의 예측 (2D-QSAR Analyses on the Binding Affinity Constants of Tetrahydropyrane and Tetrahydrofurane Analogues against Bovine Odorant Binding Protein and Predicted of High Active Molecules)

  • 박창식;성낙도
    • Reproductive and Developmental Biology
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    • 제33권3호
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    • pp.119-123
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    • 2009
  • The two dimensional quantitative structure-activity relationships (2D-QSARs) models concerning the binding affinity constants ($p[Od.]_{50}$) between 2-cyclohexyltetrahydropyrane and 2-cyclohexyltetrahydrofurane analogues as substrates, and bovine odorant binding protein (bOBP) as receptor were derived by multiple regression analyses method and discussed. The statistical quality of the optimized 2D-QSAR model (5) was good (r=0.907). From the model, the binding affinity constants ($p[Od.]_{50}$) were dependent upon the optimal value ($(TL)_{opt.}$=2.737) of total lipole (TL) of substrate molecules. Based on these findings, the high active compounds predicted by optimized 2D-QSAR model (5) were 2-(dimethylcyclohexyl)tetrahydropyrane molecule and their isomer molecules. The binding affinity constants regarding bOBP of the tetrahydrofuryl-2-yl family compounds were dependent upon the hydrophobicity (logP) of whole substrate molecules. In any case of porcine odorant-binding proteins (pOBP), the constants were dependent upon the hydrophobicity (${\pi}x={\log}P_X-{\log}P_H$) of substituents (R) in substrate molecules. Also, from the optimal values of hydrophobic constant, the hydrophobicity for bOBP influenced ca. twice time bigger (bOBP>pOBP) than that for pOBP.

Induction of SOS Genes by a Low Dose of Gamma Radiation, 10 Gy, in Salmonella enterica Serovar Typhimurium

  • Lim, Sangyong;Joe, Minho;Seo, Hoseong;Kim, Dongho
    • 방사선산업학회지
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    • 제7권2_3호
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    • pp.109-113
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    • 2013
  • In a previous study, a relatively high dose of gamma radiation (1 kGy) did not fully induce typical SOS genes such as sulA, recA, recN, and din in Salmonella Typhimurium (S. Typhimurium) (Lim et al. 2008, Gene expression profiles following high-dose exposure to gamma radiation in Salmonella enterica serovar Typhimuium. J. Radiat. Ind. 3:111-119). In this study, we examined changes in the transcriptional repertoire of S. Typhimurium after a dose of 10 Gy using DNA microarrays. It was found that more than half (~65%) of the 26 up-regulated genes belong to the SOS regulon: ten genes are typical SOS genes, and seven genes are Salmonella prophage genes, which are known to be activated by LexA cleavage. Among 29 down-regulated genes, the function of five genes with the most decreased expression is associated with carbohydrate transport and energy production. This suggests that upon exposure to gamma radiation cells may cease growing by reducing the metabolic activity, and repair DNA damage using a DNA repair system such as the SOS response system. The difference in expression of the SOS genes between a high (1 kGy) and low (10 Gy) dose of radiation shows the possibility that cells may opt for one of multiple regulatory circuits in response to the specific gamma radiation dose.

슬링을 통한 코어운동프로그램이 청소년의 특발성 척추측만증의 Cobb각과 코어근력에 미치는 효과 (Effects of Sling-Based Core Exercise Program on Cobb Angle and Core Strength of Idiopathic Scoliosis in Adolescences)

  • 유달영;양영식;박성두
    • 대한정형도수물리치료학회지
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    • 제25권2호
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    • pp.47-56
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    • 2019
  • Background: The purpose of this study was compare and analyze the Cobb's angle, core muscle strengthening in adolescents with idiopathic scoliosis and provide scientific basis for effectively treating idiopathic scoliosis in the future. Methods: The subjects of this study were 20 members of adolescent girls. Measurement tools were comprised Cobb's angle test, core muscle strengthening test. After 8 weeks of program, both groups had the same measurements as before program start. Results: The results of the study are as follows. First, the experimental group was decreased statistically significantly in Cobb's angle than the control group. Second, Both groups were increased statistically significantly in core muscle strengthening. The experimental group was increased statistically significantly direction in front, back l than the control group. Conclusion: Sling exercise with core exercise was effective in the decrease of Cobb's angle and core muscle strength than general scoliosis exercise in adolescents with idiopathic scoliosis.

비밀키를 이용한 토큰 업데이트 보안 인증 기법 (A secure token-updated authentication scheme using security key)

  • 준량;장인주;유형선
    • 한국전자거래학회지
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    • 제12권1호
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    • pp.89-97
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    • 2007
  • 최근 들어 OTP를 고려한 스마트카드 환경에서의 많은 인증 기법이 제안되고 있다. 그러나 이러한 인증 기법들이 개인 컴퓨터 환경에서 구현될 경우 개인 컴퓨터상에서는 데이터를 쉽게 읽어 내고, 유출시킬 수 있기에 위장공격이나 Stolen-Verifier 공격 등에 대하여 취약점이 노출된다. 본 논문에서는 이러한 취약점을 개선한 인증 기법을 제시함으로 스마트카드 상에서 사용되는 인증 기법이 컴퓨터 환경에서도 효율적으로 사용될 수 있도록 하였다. 본 논문이 제안하는 기법은 Stolen-Verifier 공격과 위장 공격에 안전하며, 상호 인증 기능을 부여하고 비밀 키의 생성에 있어 쉽다는 장점을 지니고 있다.

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Bi12(Si,Ge)O20 단결정의 전기 및 광학적 특성 (Electrical and Optical Properties of Bi12(Si,Ge)O20 Single Crystals)

  • 김덕훈;문정학;이찬구;이수대
    • 한국안광학회지
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    • 제1권2호
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    • pp.37-42
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    • 1996
  • $Bi_{12}(Si,Ge)O_{20}$ 단결정의 전기 및 광학적 특성을 규명하기 위하여 Czochralski법으로 단결정을 성장시켜, 직류전기전도도와 교류전기전도도 그리고 광투과도를 측정하였다. 직류전기전도도에 대한 활성화 에너지 $E_g$는 1.12 eV 이고, 광학적 갭 $E_{opt}$는 2.3 eV였다. $Bi_{12}(Si,Ge)O_{20}$ 단결정의 교류전기전도도는 측정온도 범위는 290 K에서 570 K까지 였으며 측정주파수는 50 kHz에서 30 MHz 까지 였다. 교류전기전도도는 ${\omega}^s$에 비례하는 hopping 전도 가구를 나타내었으며, 고주파수영역에서 지수값은 s=2로 구해졌다. 유전상수는 $Bi_{12}(Si,Ge)O_{20}$ 단결정의 경우 54이고 $Bi_{12}(Si,Ge)O_{20}$ 단결정의 경우 41정도의 크기를 보였다.

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Percutaneous Endoscopic Thoracic Discectomy : Posterolateral Transforaminal Approach

  • Lee, Ho-Yeon;Lee, Sang-Ho;Kim, Dong-Yun;Kong, Byoung-Joon;Ahn, Yong;Shin, Song-Woo
    • Journal of Korean Neurosurgical Society
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    • 제40권1호
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    • pp.58-62
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    • 2006
  • Objective : Development of diagnostic tools has resulted in early detection of thoracic disc herniations[TDH] even when the herniated disc is soft in consistency. In some of the cases, it is considered better not to opt for surgical treatment due to the unduly high morbidity and potential complications associated with conventional approaches. The authors have applied percutaneous endoscopic thoracic discectomy[PETD] technique to soft TDHs in order to avoid the morbidity associated with conventional approaches. Methods : Eight consecutive patients [range, 31 to 75 years] with soft lateral or central TDH [from T2-3 to T11-12] underwent PETD between May 2001 and June 2004. The patient was positioned in a prone position with intravenous sedation and local anesthetic infiltration. The authors introduced a cannula into the thoracic intervertebral foramen using endoscopic foraminoplasty technique. Discectomy was performed with mechanical tools and a laser under continuous endoscopic visualization and flu oroscopic guidance. Functional status was assessed preoperatively and postoperatively using the Oswestry Disability Index[ODI]. Results : The mean ODI scores improved from 52.8 before the surgery to 25.8 at the final follow-up. In cases of myelopathy, long tract signs showed improvement. The mean operative time was 55 minutes, and no patient required conversion to open surgery. Conclusion : The technique allows a smaller incision and less morbidity. Soft TDH is amenable to this minimally invasive approach in selected patients with myeloradiculopathy.