• 제목/요약/키워드: Functions of two independent variables

검색결과 43건 처리시간 0.029초

Packet Output and Input Configuration in a Multicasting Session Using Network Coding

  • Marquez, Jose;Gutierrez, Ismael;Valle, Sebastian;Falco, Melanis
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권2호
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    • pp.686-710
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    • 2019
  • This work proposes a model to solve the problem of Network Coding over a one-session multicast network. The model is based on a system of restrictions that defines the packet flows received in the sink nodes as functions of the outgoing flows from the source node. A multicast network graph is used to derive a directed labeled line graph (DLLG). The successive powers of the DLLG adjacency matrix to the convergence in the null matrix permits the construction of the jump matrix Source-Sinks. In its reduced form, this shows the dependency of the incoming flows in the sink nodes as a function of the outgoing flows in the source node. The emerging packets for each outgoing link from the source node are marked with a tag that is a linear combination of variables that corresponds to powers of two. Restrictions are built based on the dependence of the outgoing and incoming flows and the packet tags as variables. The linear independence of the incoming flows to the sink nodes is mandatory. The method is novel because the solution is independent of the Galois field size where the packet contents are defined.

시스템 다이나믹스를 활용한 원전 조직 및 인적인자 평가 (The System Dynamics Model for Assessment of Organizational and Human Factor in Nuclear Power Plant)

  • 안남성;곽상만;유재국
    • 한국시스템다이내믹스학회:학술대회논문집
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    • 한국시스템다이내믹스학회 2002년도 춘계학술대회발표논문집
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    • pp.19-40
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    • 2002
  • 경제 활동의 근간이 되는 에너지 공급원으로서의 원자력 발전소는 그 경제적 성과의 중요성뿐만 아니라 안전성을 확보하는 것도 매우 중요하다. <그림 1>에서 볼 수 있듯이 원전의 안전성은 하드웨어(hardware) 개선을 포함한 공학적 성능과 조직 및 인적 관리 요소에 대한 부분이 상호 작용하는 시스템 구조를 갖음에도 불구하고, 원전의 경제성과 안전성을 확보하기 위한 조직 및 인적 관리분야에 대한 연구는 기술분야에 비해 상대적으로 소홀히 취급된 경향이 있다.(중략)

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서울소재 3차 의료기관에 재원 중인 노인 환자의 재원기간에 영향을 미치는 관련 요인 (Factors Associated with Length of Stay in Elderly Inpatients in a General Hospital in Seoul)

  • 김선자;유승흠;오현주
    • 한국병원경영학회지
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    • 제12권2호
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    • pp.25-42
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    • 2007
  • To identify characteristics of elderly inpatients who had long term hospitalization in a general hospital, this study categorized into two groups who were hospitalized for less than 30 days and a group hospitalized for more than 30 days. To compare the groups the independent variables were the sociodemographical characteristics, the medical care utility characteristics, and the disease characteristics and finally analyzed factors affecting the hospitalization period. The data of 18,727 inpatients who were older than 65 years of age by the year 2005 were used and the data were analyzed using SPSS for Windows 12.0. With the results, it is necessary to provide intensive and positive management to elderly inpatients who belong to the more than 30 days group and also necessary to share roles and functions of hospital by medical network with local hospitals and clinics in order to manage long-term elderly inpatients and offer continuous post-management to discharged patients by encouraging them to use a long-term care center or by implementing an early discharge program. This study should provide many studies on how to manage the period of hospitalization efficiently on long-stay elderly inpatients in the future.

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핵심역량 지향성과 프로세스 관리역량이 IT 아웃소싱 성과에 미치는 연구 (An Empirical Investigation into the Role of Core-Competency Orientation and IT Outsourcing Process Management Capability)

  • 김용진;남기찬;송재기;구철모
    • Asia pacific journal of information systems
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    • 제17권3호
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    • pp.131-146
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    • 2007
  • Recently, the role of IT service providers has been enlarged from managing a single function or system to reconstructing entire information management processes in new ways to contribute to shareholder value across the enterprise. This movement toward extensive and complex outsourcing agreements has been driven by the assumption that outsourcing information technology functions is a reliable approach to maximizing resource productivity. Hiring external IT service providers to manage part or all of its information-related services helps a firm focus on its core business and provides better services to its clients, thus obtaining sustainable competitive advantage. This practice of focusing on the strategic aspect of outsourcing is referred to as strategic sourcing where the focus is capability sourcing, not procurement. Given the importance of the strategic outsourcing, however, to our knowledge, there is little empirical research on the relationship between the strategic outsourcing orientation and outsourcing performance. Moreover, there is little research on the factor that makes the strategic outsourcing effective. This study is designed to investigate the relationship between strategic IT outsourcing orientation and IT outsourcing performance and the process through which strategic IT outsourcing orientation influences outsourcing performance, Based on the framework of strategic orientation-performance and core competence based management, this study first identifies core competency orientation as a proper strategic orientation pertinent to IT outsourcing and IT outsourcing process management capability as the mediator to affect IT outsourcing performance. The proposed research model is then tested with a sample of 200 firms. The findings of this study may contribute to the literature in two ways. First, it draws on the strategic orientation - performance framework in developing its research model so that it can provide a new perspective to the well studied phenomena. This perspective allows practitioners and researchers to look at outsourcing from an angle that emphasizes the strategic decision making to outsource its IT functions. Second, by separating the concept of strategic orientation and outsourcing process management capability, this study provides practices with insight into how the strategic orientation can work effectively to achieve an expected result. In addition, the current study provides a basis for future studies that examine the factors affecting IT outsourcing performance with more controllable factors such as IT outsourcing process management capability rather than external hard-to-control factors including trust and relationship management. This study investigates the major factors that determine IT outsourcing success. Based on strategic orientation and core competency theories, we develop the proposed research model to investigate the relationship between core competency orientation and IT outsourcing performance and the mediating role of IT outsourcing process management capability on IT outsourcing performance. The model consists of two independent variables (core-competency-orientation and IT outsourcing process management capability), and two dependent variables (outsourced task complexity and IT outsourcing performance). Comprehensive data collection was conducted through an outsourcing association. The survey data were analyzed using a structural analysis method. IT outsourcing process management capability was found to mediate the effect of core competency orientation on both outsourced task complexity and IT outsourcing performance. Further analysis and findings are discussed.

Capabilities of stochastic response surface method and response surface method in reliability analysis

  • Jiang, Shui-Hua;Li, Dian-Qing;Zhou, Chuang-Bing;Zhang, Li-Min
    • Structural Engineering and Mechanics
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    • 제49권1호
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    • pp.111-128
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    • 2014
  • The stochastic response surface method (SRSM) and the response surface method (RSM) are often used for structural reliability analysis, especially for reliability problems with implicit performance functions. This paper aims to compare these two methods in terms of fitting the performance function, accuracy and efficiency in estimating probability of failure as well as statistical moments of system output response. The computational procedures of two response surface methods are briefly introduced first. Then their capabilities are demonstrated and compared in detail through two examples. The results indicate that the probability of failure mainly reflects the accuracy of the response surface function (RSF) fitting the performance function in the vicinity of the design point, while the statistical moments of system output response reflect the accuracy of the RSF fitting the performance function in the entire space. In addition, the performance function can be well fitted by the SRSM with an optimal order polynomial chaos expansion both in the entire physical and in the independent standard normal spaces. However, it can be only well fitted by the RSM in the vicinity of the design point. For reliability problems involving random variables with approximate normal distributions, such as normal, lognormal, and Gumbel Max distributions, both the probability of failure and statistical moments of system output response can be accurately estimated by the SRSM, whereas the RSM can only produce the probability of failure with a reasonable accuracy.

한국과 영국 사이의 국립공원 자연 경관 특색의 판별 분석 - 내용기반 영상검색의 저단계 기능 측면에서 - (Discriminant Analysis of Natural Landscape Features in National Parks between Korea and Scotland - Using Low-Level Functions of Content-Based Image Retrieval -)

  • 이덕재
    • 한국환경생태학회지
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    • 제22권3호
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    • pp.289-300
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    • 2008
  • 질감, 모양, 색채 등 내용기반 영상검색(CBIR)의 기능을 이용하여 한국의 지리산 국립공원과 영국의 케이른고럼스 국립공원의 자연 경관에 있어서의 차이를 판별하는데 본 연구의 목적이 있다. 먼저 각 국립공원의 자연경관을 디지털 사진영상으로 촬영한 후, 전형적인 경관사진을 선별하였다. 사진영상의 저단계 기능(Low-level function)이 계량화되어 수직적으로 회전된 다섯 개의 요인으로 축약되었다. 이 중 유의한 차이를 보이지 않은 물 관련 요인이 제외된 나머지 네 개의 요인에 근거한 판별선이 케이른고럼스 경관과 지리산 경관 사이에서 도출되어, 판별함수가 두 그룹을 유의하게 분할하였다($x^2(4)$=61.433; p<0.001). 고유치 2.417과 월크스 람다 0.293에 의하여 전체 변이가 두 그룹의 판별함수 평균의 차이에서 대부분 산출되었음을 확인하였다. 또한, 네 개의 독립변수가 종속변수 전체 분산의 70.7%를 설명하는 것으로 추정되었다. 경관에 대하여 가장 큰 효과를 나타내는 변수는 원거리관련 변수(r=1.073)이며, 다음으로 근거리관련 변수(r=0.896)였으며, 전체적으로 90.7%가 타당하게 분류되었다. 이는 케이른고럼스 국립공원과 지리산 국립공원 자연경관 사이에서 사진영상의 근거리 요인뿐만 아니라, 원거리 요인이 보다 경관 차이에 유의한 판별력을 보이는 것으로 해석되므로, 국립공원의 경관정체성과 관련한 원거리 스카이라인의 시각적 중요성을 보여주는 것이라 하겠다.

유동층 연소로에서 진동형 공급기의 고체혼합 및 충전물에 대한 압력요동 특성 (The Characteristics of Solid Mixing in a Vibrating Type Feeder and Pressure Fluctuation of Packing Materials for a Fluidized Bed Combustor)

  • 김미영;김의식
    • 한국안전학회지
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    • 제14권3호
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    • pp.101-109
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    • 1999
  • This study attempts to analyse the solid mixing in the feeder and the packing effect for pressure fluctuations in the fluidized bed. To study the mixing characteristics of solid in vibrating feeder for the stable operations of fluidized combustion, the system consisted of two groups of particles such that fine particles were located on the top of the coarse particles before vibratory mixing had started. The effects of packing materials on the pressure fluctuations in a fluidized bed were analysed by using a statistical method to interpret the behavior of fluidized bed. The experiments were carried out in a fluidized bed of 6.7cm-ID, and the experimental variables were particle sizes, of 115 to 1,015$\mu\textrm{m}$ in diameter and the multi-sized particles haying Rosin-Rammler and Gaussian distributions. The settled bed heights of particles to diameter ratios (L/D) were ranged from 0.5 to 2.0. And fluidizing of particles was carried out by air. The packing materials used were screen packing, and the properties of the pressure fluctuations in the fluidized bed were measured by a differential pressure transducer. The properties of the pressure fluctuations calculated were the mean, the standard deviation, and the major frequency of the power spectral density functions. From the characteristics of fluidizing, it was found that the standard deviation of pressure fluctuations could be effectively used to explain the fluidized phenomena, and the packing materials affected severely the properties of the pressure fluctuations. As a result, from the interpretation by spectral analysis, the effects of measuring radius of pressure fluctuations on standard deviation were constant in the case of the fluidized bed with and without packing materials. However, the effects of measuring the height of pressure fluctuations on standard deviations were linear increasing for the fluidized bed with packing materials, but were constant for the fluidized bed without packing materials at 4.5cm above the gas distributor. The major frequency of pressure fluctuations was found to be nearly independent of fluidized system. Also, the major frequency of pressure fluctuations decreased with increasing packing size, and it had maximum value at 10% of the packing amount.

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교통 빅데이터를 이용한 전국 도로 안전성능함수 및 안전등급 개발 연구 (Development of Safety Performance Functions and Level of Service of Safety on National Roads Using Traffic Big Data)

  • 권건안;박상민;정하림;권철우;윤일수
    • 한국ITS학회 논문지
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    • 제18권5호
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    • pp.34-48
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    • 2019
  • 본 연구는 우리나라 전체 도로 유형을 대상으로 빅데이터를 이용하여 안전성능함수(safety performance function, SPF)를 개발하고, 그것을 바탕으로 다양한 도로에 대한 안전등급을 평가함으로써 상대적으로 위험한 도로에 대한 대책을 수립할 수 있는 기초 정보를 제공하고자 하였다. 교통사고 자료를 국가표준 노드 및 링크 체계를 기반으로 전국의 도로에 매칭 하여 종속 변수로 활용하였으며, 독립변수로 링크 길이, 차로 수 등 기하구조 자료 및 한국교통연구원의 ViewT 교통량 자료, 그리고 사업용 차량에 장착된 운행기록계를 통한 위험운전행동 건수를 활용한 4개 시스템의 교통 빅데이터를 활용하여 연구를 진행하여 7개 도로 유형별 안전성능함수를 개발하고, 개발된 안전성능함수를 활용하여 도로유형별로 A, B, C, D 네 개의 안전등급을 평가하였다. 본 연구에서 사용한 방법론과 분석 결과를 토대로 우리나라의 위험도로를 선정하였다. 도출된 결과를 바탕으로 교통안전 개선사업의 대상을 선정하고 그에 따른 효과 등을 모니터링하고 계량화할 수 있을 것으로 기대된다.

축산물(畜産物) 수요(需要)의 장기여측(長期予測)에 관(關)한 연구(硏究) (A Study on the Long Term Demand Estimation for the Livestock Products)

  • 김철호
    • 농업과학연구
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    • 제10권2호
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    • pp.393-405
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    • 1983
  • The demand for livestock and poultry products including beef, pork, chicken, egg and milk whose income elasticities are relatively higher than other staple foods, has been increased significantly during the past two decades in response to the remarkable increase in per capita GNP. This trend will be continued during the fifth and the sixth five year economic development plan period beginning with 1982. The annual GNP growth rate will be 7.5% on the average during the next 10 years. It is greatly needed to estimate the demand for beef, pork, chicken egg and milk and to study the feasibilities of domestic production of livestock products for the formulation of adequate policies in order to equate the consumption and the production during the 1980s. So this study reviewed the possible changes in the food consumption patterns during the 1980s, estimated the demand for beef, pork, chicken, egg and milk by using empirical demand functions and finally made suggestions for the formulation of long term price stabilization policies for each livestock, poultry and dairy products through the equilibrium of the quantity of demand for and supply of the products. There are many factors affecting the demand for meats, but this study considered own price, prices of supplements and substitutes and per capita income as the independent variables in the demand equations. It was found that it's own price and income were most significantly affecting factors among others and the degree of substitution effects were remarkably different among the products. According to the meat demand derived in this study, per capita consumption of beef, pork and chicken in the base year 1982 was 11.2kg for total meat, 2.5kg beef, 6.0kg pork and 2.5kg chicken, 106 pieces egg, 15.1kg milk respectively, while those in 1991 were 19.3kg for total meat, 4.8kg beef, 9.6kg pork, 4.9kg chicken, 133pieces egg and 44.1kg milk. It is also predicted through this study that, when the level of production costs be maintained, the domestic production of pork and chicken will meet the demand for them during the fifth and sixth five year economic plan period. However, there will be chronic shortage of beef supply during the coming years. The annual import requirement will be 30,000tons to 40,000tons during the period. In order to stabilize the domestic livestock and poultry and dairy products market, the government should introduce measures to curb the increase in beef consumption by encouraging the consumption of pork and chicken. For this, the livestock production policy measures should be concentrated on : 1) the improvement of infrastructures of beef production by introducing advanced feeding and management technology, subsidies for the establishment of facilities and price support programs for farmers : 2) the development of dairy beef : 3) the reinforcement of the forecast systems for pork and chicken production and consumption.

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쾌락적 지능형제품의 입력 제어 방식에 따른 사용자 인식 - 지능형 바람개비 사례를 중심으로 - (Users' Perception based on Input Control Method of Hedonic Intelligent Products - Focused on an Intelligent Pinwheel -)

  • 이보람;곽소나
    • 디자인융복합연구
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    • 제16권4호
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    • pp.115-126
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    • 2017
  • 지능형제품은 모체제품이라고 불리는 기존 제품에 상호작용성이 더해진 제품으로, 제품 속성에 따라 유희, 즐거움 등의 쾌락적 속성을 모체제품에 추가한 쾌락적 지능형제품과 모체제품의 기능 수행에서 요구되는 사용 행위를 자동화함으로써 실용적 속성을 부여하는 실용적 지능형제품으로 구분될 수 있다. 실용적 지능형제품의 경우, 모체제품을 사용하는 과정에서 지능화를 통해 지원되어야 하는 사용행위를 발굴하여, 이를 자동화하면 되는 반면, 쾌락적 지능형제품은 쾌락적 속성을 부여할 수 있는 다양한 감성적 가치를 발굴하여 사용자 경험을 디자인할 수 있다. 이에 본 연구에서는 쾌락적 지능형 제품의 인터랙션디자인에 초점을 두어, 쾌락적 지능형제품의 효과적인 입력 제어 방식에 대해 탐구하였다. 입력 제어 방식은 모체제품의 기존 사용자 행위가 적용된 모방 입력 방식과 사용자 행위를 변형하여 적용한 응용 입력 방식으로 구분된다. 입력 제어 방식에 따른 사용자 인식을 알아보기 위해 실험을 실시하였고 소비자 수용도를 평가하였다. 그 결과, 응용 입력 방식이 모방 입력 방식에 비해 신규성과 흥미도에서 더 높은 평가를 받았다. 또한, 응용 입력 방식이 모방 입력 방식에 비해 높은 제품선호도를 나타냈다.