• Title/Summary/Keyword: Change-point model

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Design of U-Healthcare Access Authority Control Model Using Context Constrain RBAC Model (상황제한 RBAC 모델을 이용한 U-헬스케어 접근권한 제어모델 설계)

  • Kim, Chang-Bok;Kim, Nam-Il;Park, Seong-Hwan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.5
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    • pp.233-242
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    • 2009
  • The security of medical information need continued research about steady and flexible security model because of privacy of patient's as well as directly relation in the patient's life. In particular, u-healthcare environment is need flexible and detailed access control by variety changes of context. Control model analyzed relation of resource and authority, and analyzed authority about all accessible resource from access point using K2BASE. The context-based access control model can change flexibly authority change and role, and can obtain resource of authority granted and meaningly connected resource. As a result, this thesis can apply flexible and adaptive access control model at u-healthcare domain which context change various.

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Change point estimators in monitoring the parameters of an IMA(1,1) model (누적이동평균(1,1) 모형에서 공정 변화시점의 추정)

  • Lee, Ho-Yun;Lee, Jae-Heon
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.2
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    • pp.435-443
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    • 2009
  • Knowing the time of the process change could lead to quicker identification of the responsible special cause and less process down time, and it could help to reduce the probability of incorrectly identifying the special cause. In this paper, we propose the maximum likelihood estimator (MLE) for the process change point when a control chart is used in monitoring the parameters of a process in which the observations can be modeled as a IMA(1,1).

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The Relation of Bending Buckling Strength in Vehicle and Three Point Bending Maximum Strength of Door Impact Beam (도어 임팩트 빔의 3점 굽힘 최대강도와 차량 장착 시 굽힘 좌굴강도와의 관계)

  • Kang, Sungjong;Lee, Sangmin
    • Journal of Auto-vehicle Safety Association
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    • v.11 no.1
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    • pp.40-47
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    • 2019
  • First, three point bending analysis for the inclined press door impact beam was carried out to investigate inclination angle effect on the maximum strength with varying support distance. Next, for the system model with spring elements representing body stiffness at door mounting area, the bending structural behavior of impact beam mounted on vehicle was estimated. The mounting distance and inclination angle were changed and the beam bending buckling strength was presumed at the head displacement below which spring stiffness change has little effect on the load. Finally strength ratio to predict the bending buckling strength of impact beam mounted on vehicle from three point bending maximum strength of fixed support distance was suggested.

A Study on Students', Parents', and Teachers' Change of Perception on Creativity and Character Education through Operation of Creativity and Character Model School (창의·인성 모델학교 운영에 따른 학생, 학부모, 교사의 창의·인성교육에 대한 인식 변화)

  • Kang, Beo-Deul;Park, Jong-Un
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.2
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    • pp.257-269
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    • 2014
  • The purpose of this study was to investigate the change of perceptions of students', parents', teachers' on creativity and character education at the model school for creativity and character education. This study used pre and post tests to examine the effects of creativity and character education on students, parents, and teachers. The results were as follows. Firstly, operating model school for creativity and character education brought about the statistically meaningful changes of students' perception on creativity and character education. However, the changes seemed that the level of their perception on creativity and character education was not rational as the average is about 3.5 point. Secondly, operating model school for creativity and character education brought about the statistically meaningful changes of parents' perception on creativity and character education. However, the changes seemed that the level of their perception on creativity and character education was not rational as the average was about 3.5 point like their children. thirdly, operating model school for creativity and character education brought about the statistically meaningful changes of teachers' perception on creativity and character education. The changes seemed that the level of their perception on creativity and character education was rational as the average was about 4.5 point unlike their students and school parents. Fourthly, it seemed that the perception on creativity and character education showed a difference among students, school parents, and teachers.

A Study on Development and Application of a Particle Tracking Model for Predicting Water Quality in the Sea Area (해역의 수질예측을 위한 입자추적 모델의 개발 및 적용성에 관한 연구)

  • 정서훈;한동진
    • Journal of Environmental Science International
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    • v.6 no.3
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    • pp.239-247
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    • 1997
  • The numerical experiments using a particle tracking model have been performed for predicting the change of water Quality and shoreline. In present study, comparison of the numerical model results with the analytic solution shows that the point of the mainmum concentration and the distribution pattern is very similar. The reflection effect from the boundary was newly Introduced for making clear the effect of the closed boundary which set limits to application of a particle tracking model. The present model seems to reappear physical phenomenon well. This model shows well qualitative appearance of pollutant diffusion in Kwangan beach. Therefore, this model is regarded as a useful means for predicting diffusion movement of suspended sand, and change of water quality.

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A Parameter Estimation of Software Reliability Growth Model with Change-Point (변화점을 고려한 소프트웨어 신뢰도 성장모형의 모수추정)

  • Kim, Do-Hoon;Park, Chun-Gun;Nam, Kyung-H.
    • The Korean Journal of Applied Statistics
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    • v.21 no.5
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    • pp.813-823
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    • 2008
  • The non-homogeneous Poisson process(NHPP) based software reliability growth models are proved quite successful in practical software reliability engineering. The fault detection rate is usually assumed to be the continuous and monotonic function. However, the fault detection rate can be affected by many factors such as the testing strategy, running environment and resource allocation. This paper describes a parameter estimation of software reliability growth model with change-point problem. We obtain the maximum likelihood estimate(MLE) and least square estimate(LSE), and compare goodness-of-fit.

Maximum Power Point Tracking of Photovoltaic using Improved Particle Swarm Optimization Algorithm (개선된 입자 무리 최적화 알고리즘 이용한 태양광 패널의 최대 전력점 추적)

  • Kim, Jae-Jung;Kim, Chang-Bok
    • Journal of Advanced Navigation Technology
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    • v.24 no.4
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    • pp.291-298
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    • 2020
  • This study proposed a model that can track MPP faster than the existing MPPT algorithm using the particle swarm optimization algorithm (PSO). The proposed model highly sets the acceleration constants of gbest and pbest in the PSO algorithm to quickly track the MPP point and eliminates the power instability problem. In addition, this algorithm was re-executed by detecting the change in power of the solar panel according to the rapid change in solar radiation. As a result of the experiment, MPP time was 0.03 seconds and power was 131.65 for 691.5 W/m2, and MPP was tracked at higher power and speed than the existing P&O and INC algorithms. The proposed model can be applied when a change in the amount of power is detected by partial shading in a Photovoltaic power plant with Photovoltaic connected in parallel. In order to improve the MPPT algorithm, this study needs a comparative study on optimization algorithms such as moth flame optimization (MFO) and whale optimization algorithm (WOA).

A Study on the Color Change in a Union Fabric simulated using a 3-dimensional CAD Software and Image Analysis

  • Kim, Jong-Jun
    • Journal of Fashion Business
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    • v.10 no.6
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    • pp.9-15
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    • 2006
  • Colors of textile products or fashionable clothing play one of the most important roles. From the point of visual cues, the realism of an image is the result of a good interaction of local light scattering or transmittance model applied. A 3-dimensional CAD software was used to construct a solid plain fabric model. In order to simulate a union fabric with different warp and filling colors, rendering was performed on the fabric model. It was demonstrated that the iridescent effect, pearl effect, or superficial color change effect of the union fabric during wearer's movement could be explained using the fabric models at inclined fabric positions during viewer's observation.

Change Point Estimators in Monitoring the Parameters of an AR(1) plus an Additional Random Error Model

  • Lee, Jae-Heon;Lee, Ho-Yun
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.4
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    • pp.963-972
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    • 2007
  • When a control chart signals that a special cause is present, process engineers must initiate a search for and an identification of the special cause. Knowing the time of the process change could lead to identify the special cause more quickly, and to take the appropriate actions immediately to improve quality. In this paper, we propose the maximum likelihood estimator (MLE) for the process change point when a control chart is used in monitoring the parameters of a process in which the observations can be modeled as a first-order autoregressive(AR(1)) process plus an additional random error.

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Statistical Properties of News Coverage Data

  • Lim, Eunju;Hahn, Kyu S.;Lim, Johan;Kim, Myungsuk;Park, Jeongyeon;Yoon, Jihee
    • Communications for Statistical Applications and Methods
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    • v.19 no.6
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    • pp.771-780
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    • 2012
  • In the current analysis, we examine news coverage data widely used in media studies. News coverage data is usually time series data to capture the volume or the tone of the news media's coverage of a topic. We first describe the distributional properties of autoregressive conditionally heteroscadestic(ARCH) effects and compare two major American newspaper's coverage of U.S.-North Korea relations. Subsequently, we propose a change point detection model and apply it to the detection of major change points in the tone of American newspaper coverage of U.S.-North Korea relations.