• 제목/요약/키워드: Part145

검색결과 301건 처리시간 0.026초

안전하고 효율적인 동적 멀티캐스트 키 관리 구조 제안 (A Proposal of Secure and Efficient Dynamic Multicast Key Management Structure)

  • 박희운;이임영
    • 한국멀티미디어학회논문지
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    • 제4권2호
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    • pp.145-160
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    • 2001
  • 통신 및 컴퓨터의 보급 발전을 통해 공개 네트워크 상에서 그룹에 기반한 통신 응용 서비스의 요구가 증가하고 있다. 이러한 필요성에 따라 멀티캐스트 기반 구조에 대한 연구가 활발히 진행되고 있다. 하지만 멀티캐스트 구조에 대한 안전성과 효율성 및 확장성 부분에 대한 해결책은 아직 미비한 상태이다. 본 연구에서는 기존의 대표적인 멀티캐스트 키 관리 구조를 고찰함과 동시에 안전성과 효율성 및 확장성을 분식한다. 이에 기초해 확장성을 제공하는 안전하고 효율적인 멀티캐스트 키 관리 구조를 제안하고, 기존 방식과 통신 및 계산량 부분에 비교 분석을 통해 그 효율성을 확인한다.

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데이터스케이프 설계방법을 적용한 Villa VPRO 공간분석 연구 (A Study on analyzing the space of Villa VPRO used datascape design strategy)

  • 박영경
    • 한국실내디자인학회논문집
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    • 제13권3호
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    • pp.145-152
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    • 2004
  • The European architects including MVRDV, Rem Koolhaas, Van Berkel, and Zaha Hadid tend to use the their own design strategy based on the objective data. This Architectural design method leads to make new paradigm of contemporary architecture. For the purpose of the understanding a part of new architecture paradigm I will analyze the case of Villa VPRO designed by MVRDV. At the result, I can draw the following conclusions. First, through collecting and analyzing data, drawing design concept and planning the space program, they decided on the design strategies of Villa VPRO. They designed the space volume having 42.4m$\times$42.4m floors and infiltrated environmental elements to solve the problems about deep space. Second, Villa VPRO was constructed by 'creative space-making system: a series of floors much like a geological formation, the continuous floors interconnected by spatial means, the precision bombardments of snake-like holes, open elevations, the stacking spaces. Third, Villa VPRO produced the spectacle space effect the various formation of continuous floors make a lot of difference space types in this building. Also they lead to move naturally and give event space. A numbers of holes and openness make it possible to provide friendly environment with combining light and air with views of the surrounding and transparency. And using the method of stacking many types of space make the differences in height.

항법장치 simulator 기반의 RNASA-TLX 를 이용한 항법장치 운전자 mental workload 평가에 관한 연구 (Simulator-Based Mental Workload Assessment of the In-Vehicle Navigation System Driver Using Revision of NASA-TLX)

  • 차두원;박범
    • 산업공학
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    • 제10권1호
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    • pp.145-154
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    • 1997
  • In developing the HMI(Human-Machine Interface) evaluation system for the IVNS(In-Vehicle Navigation System), design guidelines and evaluation methods are the most crucial problems for its use and efficiency. As the part of this system, focused on the final product of the database, subjective mental workload assessment is seriously considered to evaluate the driver's own driving task using the IVNS. This paper suggests the methodology for the ergonomic assessment of the IVNS that corresponds to the subjective measurement of the driver's mental workload by rating his or her own driving task. For this approach, Revision of NASA-Task Load Index(RNASA-TLX) was developed which translated and revised the version of NASA-TLX that is generally accepted an efficient and powerful method for evaluating the in-vehicle information systems. To verify the RNASA-TLX, an experiment was conducted in a real road situation, because the result of the laboratory approach is uncertain and has the differences from the real road test.

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The Use of Particle Swarm Optimization for Order Allocation Under Multiple Capacitated Sourcing and Quantity Discounts

  • Ting, Ching-Jung;Tsai, Chi-Yang;Yeh, Li-Wen
    • Industrial Engineering and Management Systems
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    • 제6권2호
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    • pp.136-145
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    • 2007
  • The selection of suppliers and the determination of order quantities to be placed with those suppliers are important decisions in a supply chain. In this research, a non-linear mixed integer programming model is presented to select suppliers and determine the order quantities. The model considers the purchasing cost which takes into account quantity discount, the cost of transportation, the fixed cost for establishing suppliers, the cost for holding inventory, and the cost of receiving poor quality parts. The capacity constraints for suppliers, quality and lead-time requirements for the parts are also taken into account in the model. Since the purchasing cost, which is a decreasing step function of order quantities, introduces discontinuities to the non-linear objective function, it is not easy to employ traditional optimization methods. Thus, a heuristic algorithm, called particle swarm optimization (PSO), is used to find the (near) optimal solution. However, PSO usually generates initial solutions randomly. To improve the PSO solution quality, a heuristic procedure is proposed to find an initial solution based on the average unit cost including transportation, purchasing, inventory, and poor quality part cost. The results show that PSO with the proposed initial solution heuristic provides better solutions than those with PSO algorithm only.

기계적 합금방법으로 제조한 극초미세 조직의 W-Cu 복합분말의 금속사출성형 연구 (Metal Injection Molding of Nanostructured W-Cu Composite Powders Prepared by Mechanical Alloying)

  • 김진천
    • 한국분말재료학회지
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    • 제5권2호
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    • pp.145-153
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    • 1998
  • W-Cu alloy is attractive to thermal managing materials in microelectronic devices because of its good thermal properties. The metal injection molding (MIM) of W-Cu systems can satisfy the need for mass production of the complex shaped W-Cu parts in semiconductor devices. In this study, the application of MIM process of the mechanically alloyed (MA) W-Cu composite powders, which had higher sinterability were investigated. The MA W-Cu powders and reduction treated (RT) powders were injected by using of the multicomponent binder system. The multi-stage debinding cycles were adopted in $N_2$ and $H_2$ atmosphere. The isostatic repressing treatment was carried out in order to improve the relative density of brown parts. The brown part of RT W-Cu composite powder sintered at 110$0^{\circ}C$ had shown the higher sinterability compared to that of MA powder. The relative sintered density of all specimens increased to 96% by sintering at 120$0^{\circ}C$ for 1 hour. The relationship between green density and the sintering behavior of MA W-Cu composite powder was analyzed and discussed on the basis of the nanostructured characteristics of the MA W-Cu composite powder.

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인공위성 탑재용 소형 극자외선 태양망원경 공학 모형 설계 (DESIGNING A SMALL-SIZED ENGINEERING MODEL OF SOLAR EUV TELESCOPE FOR A KOREAN SATELLITE)

  • 한정훈;장민환;김상준
    • Journal of Astronomy and Space Sciences
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    • 제18권2호
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    • pp.145-152
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    • 2001
  • 태양의 극자외선 복사를 연구하기 위한 인공위성 탑재용 소형 극자외선 태양망원경의 공학 모형을 설계하였다. 극자외선 태양망원경은 $584.3AA$(He I)과 $629.7AA$(OV)의 두 파장대역에서 태양을 관측하기 위한 목적으로 설계되었다. 광학계는 Ritchey-Chr 샤두 방식이고, 망원경의 유효구경과 유효 초점 거리는 각각 80mm, 640mm이다. 회전 필터 휠을 사용하여 He I과 OV 방출선을 관측할 수 있도록 하였다. 검출기의 MCP (Microchannel Plate)는 채널 길이 대 직경의 비가 40:1인 Z-stack 타입이고, photocathode로서 KBr이 MCP 초점면에 코팅되며, MCP와 CCD는 fiber optic taper로 연결되도록 디자인하였다. 광학계 설계에 대한 분석은 광학계산용 상용 소프트웨어를 이용하였다.

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예측 기반 형태소 분석기와 결합 독립 모형 기반 품사 태거 및 고속 명사 추출기 (A Predictive Morphological Analyzer, A Part-of-Speech Tagger Based on Joint Independence Model, and A Fast Noun Extractor)

  • 이상주;박봉래;김진동;류원호;이도길;임해창
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 1999년도 제11회 한글 및 한국어 정보처리 학술대회 및 제1회 형태소 분석기 및 품사태거 평가 워크숍
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    • pp.145-150
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    • 1999
  • 본 논문에서는 한국어 자연어 정보처리 기술 표준화를 위한 형태소 분석기 및 품사 태거 평가 대회(MATEC99)에 참여한 고려대학교의 형태소 분석기, 품사 태거, 그리고 명사 추출기를 설명하고 평가 결과를 기술한다. 형태소 분석기는 입력된 어절을 우에서 좌로 분석하며 각 상태에 대한 예측 정보를 활용하여 불필요한 분석 후보에 대한 탐색을 수행하지 않도록 한다. 품사 태거로는 띄어쓰기를 고려한 형태소 품사 2-그램 확률과 띄어쓰기를 고려한 형태소 어휘-품사 3-그램 어휘 확률을 이용하는 결합 독립 모형을 사용한다. 고속 명사 추출기는 고속의 FST 사전과 한국어 특성을 반영한 휴리스틱을 이용한다.

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캉가루식 돌보기가 미숙아의 체중과 스트레스 호르몬[코티졸]에 미치는 영향 (The Effect of Kangaroo Care on Weight and Stress Hormone(Cortisol) in Premature Infants)

  • 장미영
    • Child Health Nursing Research
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    • 제14권2호
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    • pp.138-145
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    • 2008
  • Purpose: This study, using a pre-posttest design of non-equivalence comparative groups, was done to determine effects of KC (kangaroo care) on weight and SH (stress hormone) of premature infants. Method: Participants were 31 premature infants assigned to KC(14) or CG(control group)(17). Data were collected from June 2006 to February 2007. KC was given for 60 minutes at a time, Mon, Wed, and Fri for a 10 times. Body weight was measured at a fixed time daily and serum cortisol was examined as part of routine blood testing, frequent for premature infants. Results: The weight for infants in the KC group was higher than the control. The difference was significant between both the two groups, and the 2 measurement times(F=12.7, p=.001). SH(cortisol) in infants of KC group decreased than CG, but there was no valid difference from the statistical viewpoint. Conclusion: The result of the study suggest that KC contributes to weight increase in premature infants and also that KC is effective for SH reduction in spite of the lack of statistical validity. Therefore, our conclusion is that KC can be used as an independent nursing intervention for development and advance of premature infants.

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여행비용모형을 이용한 전남 바다목장 해역 유어활동의 경제적 가치 추정 (Estimating the Economic Value of Recreational Fishing in the Jeonnam Marine Ranching Area)

  • 서주남;김도훈;강성경
    • 수산경영론집
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    • 제43권2호
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    • pp.41-49
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    • 2012
  • This study aimed to estimate the economic value of the recreational fishing in the Jeonnam marine ranching area as a part of the total socioeconomic evaluation of the Jeonnam marine ranching program. A travel cost method was applied to the estimation of economic value of the recreational fishing in the Jeonnam marine ranching area and input variables included annual fishing trip days, average travel cost per trip, average catch amount, monthly income, marriage, age, and personal perception on the marine ranching program. In the analysis, due to its characteristic of count data, both poisson model and negative binomial model were used. Model results indicated that a negative binomial model was statistically more suitable than the poisson model as the overdispersion problem occurred in the poisson model. All signs of the estimated parameters were estimated as previous studies showed. Based on the results, the economic value per trip of the recreational fishing in the Jeonnam marine ranching area was estimated to be 145,000 won and the annual total economic value of the recreational fishing in the Jeonnam marine ranching area was analyzed to be 2,514,000 won. In addition, the change of total value by catch rate showed that the economic value could be increased by 180,900 won as the catch increased by one kilogram.

3D 스테레오스코픽(Stereoscopic)기술의 효율적 활용에 관한 연구 (Research on Efficient Usage of 3D Stereoscopic Technology)

  • 김지수
    • 한국콘텐츠학회논문지
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    • 제10권2호
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    • pp.138-145
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    • 2010
  • 입체영상 기술은 차세대 입체 멀티미디어 정보통신 분야에서 공통적으로 요구되는 핵심 기반기술이라 할 수 있다. 현실과 가까운 자연스러운 영상을 표현하고자 하는 입체영상의 구현은 인간이 끊임없이 노력해온 부분으로, 초기의 시각 인식체계에서 시작해 양안시차를 이용한 입체사진을 거쳐 동영상 입체시대로 이행 되었다. 생활이 변화하고, 새로운 문화가 형성되고, IT산업 확장 등 핵심 트렌드의 바탕에는 가상을 실제처럼 구현하는 기술의 발전이 있으며, 그 중심에는 3D 입체영상 기술이 있다. 본 논문에서는 3D 입체영상 기술개발 동향 및 개발전략을 살펴보고, 지속적인 시장 확대를 위한 3D 입체영상 기술의 효율적 활용방안을 제시하고자 한다.