• 제목/요약/키워드: Park function

검색결과 12,071건 처리시간 0.038초

진폭 마스크와 2D 카오스 함수를 이용한 다중 이미지 광학 암호화 (Optical encryption of multiple images using amplitude mask and 2D chaos function)

  • 김활;전성빈;김도형;박노철;박영필
    • 정보저장시스템학회논문집
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    • 제10권2호
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    • pp.50-54
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    • 2014
  • Object image using DRPE(Double Random Phase Encryption) in 4f system is encrypted by space-division method using amplitude mask. However, this method has the weakness for the case of having partial data of amplitude mask which can access the original image. To improve the security, we propose the method using the 2-dimension logistic chaos function which shuffles the encrypted data. It is shown in simulation results that the proposed method is highly sensitive to chaos function parameters. To properly decrypt from shuffled encryption data, below 1e-5 % errors of each parameter should be required. Thus compared with conventional method the proposed shows the higher security level.

불완전 결함 발견과 구문 반복 실행을 고려한 커버리지 기반 신뢰성 성장 모형 (A Coverage-Based Software Reliability Growth Model for Imperfect Fault Detection and Repeated Construct Execution)

  • 박중앙;박재홍;김영순
    • 정보처리학회논문지D
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    • 제11D권6호
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    • pp.1287-1294
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    • 2004
  • 최근 소프트웨어 신뢰성을 평가하기 위해 신뢰성 측도와 커버리지 간의 관계가 연구되고 있다. 특히 커버리지에 기반한 소프트웨어 신뢰성 성장 모델에서 평균치 함수는 소프트웨어의 신뢰성 성장을 나타내는데 매우 중요한 역할을 한다. 본 논문은 커버리지에 기반한 기존 모형들의 문제점을 평균치 함수와 그 모형이 근거하는 가정을 바탕으로 파악하고, 그 문제점을 해결하기 위한 새로운 평균치 함수를 제안한다. 제안된 새로운 평균치 함수는 불완전 결함 발견과 구문의 반복 실행이 허용되는 일반적인 테스팅 환경에서 도출된 결과이다. 마지막으로 실제 데이터에 제안된 모형을 적용하여 그 성능을 평가한다.

Alleviation of Senescence via ATM Inhibition in Accelerated Aging Models

  • Kuk, Myeong Uk;Kim, Jae Won;Lee, Young-Sam;Cho, Kyung A;Park, Joon Tae;Park, Sang Chul
    • Molecules and Cells
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    • 제42권3호
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    • pp.210-217
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    • 2019
  • The maintenance of mitochondrial function is closely linked to the control of senescence. In our previous study, we uncovered a novel mechanism in which senescence amelioration in normal aging cells is mediated by the recovered mitochondrial function upon Ataxia telangiectasia mutated (ATM) inhibition. However, it remains elusive whether this mechanism is also applicable to senescence amelioration in accelerated aging cells. In this study, we examined the role of ATM inhibition on mitochondrial function in Hutchinson-Gilford progeria syndrome (HGPS) and Werner syndrome (WS) cells. We found that ATM inhibition induced mitochondrial functional recovery accompanied by metabolic reprogramming, which has been known to be a prerequisite for senescence alleviation in normal aging cells. Indeed, the induced mitochondrial metabolic reprogramming was coupled with senescence amelioration in accelerated aging cells. Furthermore, the therapeutic effect via ATM inhibition was observed in HGPS as evidenced by reduced progerin accumulation with concomitant decrease of abnormal nuclear morphology. Taken together, our data indicate that the mitochondrial functional recovery by ATM inhibition might represent a promising strategy to ameliorate the accelerated aging phenotypes and to treat age-related disease.

소프트웨어 신뢰도 평가를 위한 테스트 적용범위에 대한 연구 (A Study on Test Coverage for Software Reliability Evaluation)

  • 박중양;박재흥;박수진
    • 정보처리학회논문지D
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    • 제8D권4호
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    • pp.409-420
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    • 2001
  • 소프트웨어 신뢰도는 소프트웨어 시스템의 매우 중요한 특성으로 테스팅 하는 동안 소프트웨어 신뢰도를 평가하기 위해 테스트 적용범위 정보를 이용하는 방법이 최근 시도되고 있다. 본 논문은 최근 문헌에 나타난 테스트 적용범위를 이용하는 소프트웨어 신뢰도 성장모델들을 검토하여 이들을 2개 부류로 분류한 다음 각각의 문제점을 논의하고 현실적 타당성을 검토한다. 더불어, 새로운 평균치 함수와 적절한 적용범위를 선택하기 위한 절차를 제안한다.

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품질손실함수를 이용한 규격치 결정방법의 성능평가 (Comparative Performance of the Size Determination Method Using Quality Loss Function)

  • 임성욱;강현정;박영택
    • 품질경영학회지
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    • 제38권4호
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    • pp.587-592
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    • 2010
  • This paper deals with the performance evaluation of determining production size specifications. A customer who does not find the size specification he or she wants may purchase rather a larger or smaller one, but the purchasing desire decreases as the difference between the required and the prepared sizes increases. Introducing a generalized quality loss function which reflects how much the purchasing desire changes according to the difference, Park and Kim(1992) formulated a mathematical model for determining the size specifications so as to minimize the expected loss. Afterward the model has been applied to the determination of sizing system for mail order clothing and brassiere (Lee and Choi, 1996; Chun, et.al., 1996). The performance of the size determination method proposed by Park and Kim is evaluated in this paper. Usually the intervals between two successive size specifications are determined to be equal, but the size determination method compares favorably with the equidistance case, and more favorably if the population distribution is more skewed.

유전알고리즘에 의한 강봉의 구조특성행렬 산출법 (Identification of Structural Characteristic Matrices of Steel Bar by Genetic Algorithm)

  • 박석주;제해광;이금주;박영범;박경일
    • 한국소음진동공학회논문집
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    • 제20권10호
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    • pp.946-952
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    • 2010
  • A method for the identification of structural characteristic parameters of a steel bar in the matrices form such as stiffness matrices and mass matrices from frequency response function(FRF) by genetic algorithm is proposed. As the method is based on the finite element method(FEM), the obtained matrices have perfect physical meanings if the FRFs got from the analysis and the FRFs from the experiments were well coincident each other. The identified characteristic matrices from the FRFs with maximun 40 % of random errors by the genetic algorithm are coincident with the characteristic matrices from exact FEM FRFs well each other. The fitted element diameters by using only 2 points experimental FRFs are similar to the actual diameters of the bar. The fitted FRFs are good accordance with the experimental FRFs on the graphs. FRFs of the rest 9 points not used for calculating could be fitted even well.

Comparison of Underwater and Overground Treadmill Walking Exercise to Improve Gait and Physical Function in People After Stroke

  • Park, Si-Eun;Lee, Mi-Joung;Yoon, Bum-Chul;Lee, Byung-Hee;Shin, Hee-Joon;Choi, Wan-Suk;Park, Sung-Kyu;Jeon, Hye-Mi;Moon, Ok-Kon;Lee, Suk-Hee;Min, Kyoung-Ok
    • 국제물리치료학회지
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    • 제1권2호
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    • pp.120-125
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    • 2010
  • The purpose of this study was to compare the effects of treadmill walking in underwater and overground which affects gait and physical function of people who have had a stroke. Twenty people after a stroke who have become hemiplegic over 6 months were participated. Participants were divided into two groups: underwater treadmill group(UTG) and overground treadmill group(OTG). The intervention was done 4 times per weeks for 6 weeks and 1 session lasted for 30 minutes. Gait and physical function elements were measured at baseline, at the middle(3 weeks) and at the end of the intervention(6 weeks). For the elements of gait, walking velocity, affected stance phase, affected weight bearing were assessed. For the elements of physical function, Short Form 8(SF-8) health survey was used. The result of this study showed that both groups improved similarly in walking velocity. However participants in UTG improved more than those in OTG in affected stance phase(p<.05), affected weight bearing(p<.05) and emotional aspect(p<.001). Based on the results of this study, it can be suggested that treadmill walking both in underwater and on the ground can be effective in improving hemiplegic gait and physical function of people who have had a stroke. The result also suggest that the underwater treadmill exercise can be more effective than overground treadmill in restoration of gait in people after stroke.

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대학기숙사 교육기능공간의 매개변수를 통한 인과분석 (Causal Analysis of Education Function Space Parameters of University Dormitory)

  • 박행자;박성진;노영란
    • 한국주거학회논문집
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    • 제21권4호
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    • pp.23-31
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    • 2010
  • This study aims to examine the educational function space of university dormitories at local universities with corridor centered structure in Honam area regions based on direct and indirect parameters on the whole satisfaction of users in residential environment factors and personal characteristics. First, according to relations among parameters, educational and cultural activities of four major activities within the dormitory had indirect influences on social activities, eating and sleeping activities had no direct influence on other activities. And social activity had direct influence on the general satisfaction as an important parameter and educational and cultural activities had indirect influence on the whole satisfaction through social activities. Detailed results show that, in the first educational activities directly affecting the lighting and air conditioning facilities (0.22), safety (0.326), Territoriality (0.327), the space density (-0.167), directions (-0.166) and yeohyang having personal characteristics and the safety of the second cultural activities (0.183), Territoriality (0.361), Aesthetics (-0.13) and the personal characteristics Sex (-0.179), the direct effect, third, and erosion has a direct impact on activity The flexibility of the space factor (-0.128) and Territoriality (0.38) and the personal characteristics grade (0.172), respectively. Fourth in social activities directly affecting the pathfinding (-0.104), and parameter, education (0.388) and cultural activities (0.445), and some of the factors affecting the indirect lighting and air conditioning facilities, safety, and Territoriality, the space density, directions, grade, they could influence through educational activities to be analyzed. That is, territoriality in educational function space is the important factor that users react very sensitively in educational, eating and sleeping activities and educational function space must secure area and division considering personal and public use as the space accommodating activity which is lacking in unit residential space. Accordingly, the safety of educational function space in university dormitory is considered as the fundamental safety matter on the fire prevention, hygiene and cleanness for users in the satisfaction of educational and cultural activities.