• Title/Summary/Keyword: Lee Sam

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An Effective Buffer Management Scheme for Sequential and Looping References (순차 참조와 순환 참조들을 고려한 버퍼 캐쉬 관리 기법)

  • Kim, Jong-Min;Choe, Jong-Mu;Kim, Je-Seong;Lee, Dong-Hui;No, Sam-Hyeok;Min, Sang-Ryeol;Jo, Yu-Geun;Kim, Jong-Sang
    • Journal of KIISE:Computer Systems and Theory
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    • v.28 no.1_2
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    • pp.33-44
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    • 2001
  • 최근 버퍼 캐쉬의 성능을 향상시키기 위한 많은 블록 교체 기법들이 제안되었으며 이 중에서 작업 집합 (working set) 변화에 잘 적응하고 구현이 용이한 Least Recently Used (LRU) 블록 교체 기법이 널리 사용되고 있다. 그러나 LRU 블록 교체 기법은 블록들이 규칙적인 참조 패턴을 보이면서 순차 참조되거나 순환 참조될 때 이 규칙성을 적절히 이용하지 못해 성능이 저하되는 문제점을 가진다. 본 논문에서는 다중 응용 트레이스를 이용하여 LRU 블록 교체 기법의 문제점을 관찰하고, 이 문제점을 해결하는 통합된 형태의 효율적인 버퍼 관리 (Unified Buffer Management, 이하 UBM) 기법을 제안한다. UBM 기법은 순차 참조 및 순환 참조를 자동 검출하여 분리된 공간에 저장하고 이들 참조에 적합한 블록 교체 기법으로 이 공간을 관리한다. 또한 순차 참조와 순환 참조를 위한 공간과 나머지 참조를 위한 공간의 비율을 최적으로 할당하기 위해 온라인에서 수집된 정보를 이용하여 계산된 단위 공간 증가당 예상 버퍼 적중 증가율을 이용한다. 다중 응용 트레이스 기반 시뮬레이션 실험에서 UBM 기법의 버퍼 적중률은 LRU 블록 교체 기법에 비해 평균 12%, 최대 28%까지 향상된 결과를 보였다.

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Numerical Simulation on Ventilation Characteristics of an Underground Bus Parking Lot (버스전용 지하주차장의 환기 특성에 관한 수치해석적 연구)

  • Seung, Sam-Sun;Lee, Seung-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.2
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    • pp.179-184
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    • 2007
  • In this paper, the ventilation characteristics of an underground parking lot with 17 buses has been investigated for two cases by computational fluid dynamics. It has been found that the average concentration of CO and $NO_x$ gas in the parking lot were 1.3 and 0.3 ppm respectively, when four buses operated. When the fifteen vehicles stopped in the parking lot, the average concentration of CO and $NO_x$ gas was 2.9 and 0.8 ppm respectively. The average concentration of two pollutants$(CO,\;NO_x)$ are lower than the standard values. Therefore the facilities and its location is proper to ventilation.

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Role of Dual Flagella in the Pathogenesis of Vibrio parahaemolyticus

  • Lee, Hwa-Gyu;Jeong, Byung-Gon;Park, Kwon-Sam
    • Fisheries and Aquatic Sciences
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    • v.14 no.2
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    • pp.73-78
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    • 2011
  • Vibrio parahaemolyticus possesses two flagella systems: polar and lateral flagella for swimming in liquid and swarming on solid surfaces or in viscous environments. To elucidate the pathogenic role of these dual flagella systems, we constructed single- and double-deletion mutants of the lafA and flhAB flagellum genes and investigated their biofilm formation, cell adhesion, and colonization of the small intestine of suckling mice. The double-mutant strain was more impaired in biofilm formation than either of the single-mutant strains. In addition, the lafA, flhAB, and double-mutant strains showed 40%, 45%, and 60%, respectively, lower adherence to HeLa cells than the wild-type strain. Moreover, the lafA, flhAB, and double-mutant strains exhibited 49%, 5.6 and 6.7 times, respectively, lower colonization in a competition assay than the wild-type strain. These findings indicated that polar flagella were more important than lateral flagella for the pathogenesis of V. parahaemolyticus.

A Study on the Analysis for the Strength of Bailey Panel Bridge (장간조립교 주요 부재의 강도 분석 연구)

  • Lee, Jong-Woo;Yoo, Sam-Hyun;Kim, In-Soo;Kim, Tae-Yang;Choi, Hyun-Ho;Yoon, Woo-Seob;Kim, Young-Cheol
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.1
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    • pp.15-21
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    • 2011
  • In this paper, the results of experimental analysis for the chemical composition and strengh verification of Bailey Panel Bridge have been presented. Some of main sections of bailey bridge colllected from military engineer troops were prepared for the chemical composition and strengh verification. The composition test and strength verification were conducted by using the optical microscope and Scanning Electron Microscope(SEM), Automatic Control Spark Emission Spectrometer(OBLF), X-ray Fluorescence Spectroscopy(XRF) and Instron measurement. The results showed that currently used sections of bailey bridge passed the strength verification and could be operated in drill of troops and battle fields.

Model of the ebXML-based BPSS Conformance Validation for Interoperability (ebXML 기반 상호운용성을 위한 BPSS 적합성 검증 모델)

  • Shin, Myeong-Sook;Hong, Seong-Pyo;Kim, Kil-Sam;Lee, Joon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.653-656
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    • 2007
  • A concern about the ebXML concentrated, the necessity for Validation request among the ebXML sollutions has become both at home and abroad. There aren't any test implement for Validation of BPSS. The ebXML BPSS system establishment related to ebMS Standard Conformance and Interoperability is required. In this paper, We'll suggest system model to estimate Conformance of document in accordance with case items to frame the ebXML BPSS Validation items.

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A study on the Context-Aware Architecture for Ubiquitous on Computing System (유비쿼터스 컴퓨팅 시스템을 위한 상황인식 구조에 관한 연구)

  • Doo, Kyoung-Min;Chi, Sam-Hyun;Kim, Sun-Guk;Chen, Yun;Lee, Kang-Whan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.418-422
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    • 2007
  • Ubiquitous Computing System란, 언제 어디서나 통신 및 컴퓨팅이 가능하고 컴퓨팅 시스템이 상호간에 정보를 공유하고 협력하는 컴퓨팅 시스템이다. 이로써 기존의 컴퓨팅 환경과 같이 사용자와 컴퓨터간의 대화형 상호작용이 아닌 물리적인 환경 상황(Context)등을 시스템이 스스로 인식하고 이를 기반으로 사용자와의 상호 작용을 지원하는 상황인식 기술이 필수적인 요소로 부각되고 있다. Ubiquitous Computing System을 위해 사용자 및 주변 환경의 정보를 감지하는 센서(Sensor) 기술이 필요하다. 하지만 사용자 및 주변 환경으로부터 입력되는 불확실하거나 모호한 상황정보에 대한 표현과 추론에 대한 연구는 부족한 실정이다. 본 논문은 Rule based System을 활용하여 CRS(Context Recognition Switch)라는 새로운 개념을 도입한 Context Aware Architecture를 제시한다. CRS는 유비쿼터스 컴퓨팅 시스템을 위해서는 센서로부터 복합적으로 인지된 사용자 정보 및 주변환경의 정보를 사용자로부터 수동적으로 설정되거나 System의 지속적으로 수집된 정보의 통계 값인 Reference Value와 비교하여, 각 상황에 따른 개별적이고 특화된 서비스를 실행을 하도록 제공한다. 이로써 같은 정보의 입력이 들어와도 그 주변 환경의 상황에 따라 사용자의 필요에 최적화된 실행을 할 수 있다. 마지막으로, Ubiquitous Computing System의 향후 발전 가능성을 예상해고, 본 논문에서 제시한 Context Aware Architecture의 유용성을 짐작해 본다.

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Cloning and Sequencing of the Gene Involved in Morphological Change of Zoogloea ramigera 115SLR

  • Lee, Sam-Pin;Kim, Tae-Rahk;Sinskey, Anthony-John
    • Journal of Microbiology and Biotechnology
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    • v.10 no.2
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    • pp.161-168
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    • 2000
  • Plasmid pLEX3 isolated from the recombinant cosmid library of Zoogloea ramigera 115 was found to be responsible for the restoration of the rugose colony phenotype. To confirm the essential region responsible for the complementation, subclones were constructed from plasmid pLEX3 and transformed into mutant strain Z. ramigera 115SLR. The recombinant plasmids pLEX10 and pLEX11 were shown to complement the slime-forming property of Z. ramigera 115SLR. In a compositional analysis of the exopolysaccharides from Z. ramigera 115, Z. ramigera 115SLR, and Z. ramigera 115SLR harboring plasmid pLEX11, the exopolysaccharides showed a similar composition with glucose, galactose, and side chain groups. The complete nucleotide sequence of the 3.25kb genocim DNA insert in plasmid pLEX11 was determined and its analysis identified two open reading frames which could encode two proteins. The gene products derived form the two open reading frames were confirmed by and in vivo transcription using a T7-RNA polymerase. The ORF1 produced a 30 kDa protein, whereas the ORF2 was found responsible for the complementation of the morphological mutation and produced a 14 kDa protein. An in vivo gene expression of plasmid pTEX10 showed another open reading frame encoding a 50 kDa protein. The gene products form ORF1 and ORF2 are regarded as novel proteins which do not show any homology with other proteins.

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Characterization and cDNA Cloning of a Defensin-Like Peptide, Harmoniasin, from Harmonia axyridis

  • Kim, In-Woo;Lee, Joon-Ha;Park, Ha-Yan;Kwon, Young-Nam;Yun, Eun-Young;Nam, Sung-Hee;Kim, Seong-Ryul;Ahn, Mi-Young;Hwang, Jae Sam
    • Journal of Microbiology and Biotechnology
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    • v.22 no.11
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    • pp.1588-1590
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    • 2012
  • We compared the mRNA expression profile of the Harmonia axyridis larvae that were either untreated or treated with LPS. The extracted mRNAs were subjected to ACP RT-PCR analysis using a combination of arbitrary primers and oligo (dT) primer. Among the 47 DEGs differentially expressed, we identified a cDNA showing homology with defensin-like antibacterial peptide. The cDNA showed a putative 32-residue signal sequence and a 50-residue mature peptide named harmoniasin. We also investigated the antibacterial activity of the harmoniasin analog, which exhibited potent antibacterial activities against Gramnegative and -positive bacteria strains and it also evidenced no hemolytic activity.

A Study on Input Current Waveform Analysis for Step Up-Down AC-DC Converter of High Power Factor added Electric Isolation (고역률 스텝 업-다운 절연형 AC-DC 컨버터의 입력전류 파형분석에 관한 연구)

  • Kwak, Dong-Kurl;Kim, Choon-Sam;Lee, Bong-Seob;Kim, Sang-Hoon
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.34-36
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    • 2008
  • This paper is given a full detail of mathematical analyses of input current for novel active type power factor correction(PFC) AC-DC converter of step up-down added electric isolation. These are compared with harmonics components of input current for a conventional PFC converter of electric isolation type. The proposed PFC converter is constructed in using a new loss-less snubber circuit to achieve a soft switching of control device. Also the proposed converter for discontinuous conduction mode(DCM) eliminates the complicated circuit control requirement and reduces the size of components. The input current waveform in the proposed converter is got to be a sinusoidal form of discontinuous pulse in proportion to magnitude of ac input voltage under the constant duty cycle switching. Therefore, input power factor is nearly unity and the control method is simple. Particularly, the stored energy of loss-less snubber capacitor is recovered with input side and increases input current from resonant operation. The result is that input power factor of the proposed converter is higher than that of a conventional PFC converter. Some simulative results on computer and experimental results are included to confirm the validity of the analytical results.

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Inkjet Printing of Single Wall Carbon Nanotubes for Transparent Conductive Films

  • Song, Jin-Won;Yoon, Yeo-Hwan;Kim, Joon-Dong;Lee, Eung-Sug;Choi, Byung-Sam;Kim, Jae-Ho;Han, Chang-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1257-1260
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    • 2007
  • A single-wall carbon nanotube (SWNT) transparent conductive film (TCF) was fabricated using a simple inkjet printing method. The TCF could be selectively patterned by controlling the dot size to diameters as small as $34\;{\mu}m$. In this repeatable and scalable process, we achieved 71% film transmittance and a resistance of 900 ohm/sq sheet with an excellent uniformity, about ${\pm}\;5%$ deviation overall. Inkjet printing of SWNT is substrate friendly and the TCF is printed on a flexible substrate. This method of fabrication using direct printing permits mass production of TCF in a large area process, reducing processing steps and yielding low-cost TCF fabrications on a designated area using simple printing.

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