• Title/Summary/Keyword: Multiple-Case Study

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A Study on Multiple Bad Data Detection using Binary PSO (이진 PSO를 이용한 Multiple Bad Data 검출에 관한 연구)

  • Jeong, Hee-Myung;Park, June-Ho;Lee, Hwa-Seok
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.270_271
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    • 2009
  • The identification of multiple bad data, especially when mutually interacting, may be difficult to handle, since the well known procedures based on the normalized or weighted residuals may become faulty. In such a case, successive elimination of the measurement with the largest normalized residual may result in the suppression of correct measurements instead of the bad data. Then the problem of identifying bad data is considered as a combinatorial decision procedure. In this paper, binary PSO is used for the identification of multiple bad data in the power system state estimation. The proposed binary PSO based procedures behave satisfactorily in the identifying multiple bad data. The test is carried out with reference to the IEEE-14 bus system.

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Developing the Mobile GIS System Using CDMA Networking - Case Study of Forest Fire Ground Fighting Team - (CDMA 데이터망을 이용한 Mobile GIS 시스템 개발 - 산불발생시 지상진화대원 업무를 사례로 -)

  • Jo, Myung-Hee;Lee, Myung-Bo;Jo, Yun-Won;Kim, Dong-Hyun;Shin, Dong-Ho
    • Fire Science and Engineering
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    • v.21 no.1 s.65
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    • pp.60-68
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    • 2007
  • In order to guide the safe extinguishment duty of forest fire ground fighting team and acquire its exact location information in case of a large scale of forest fire, it is very important to monitor the real time coordination data the forest fire ground fighting team. In this study the guidance for safe extinguishment duty of forest fire ground fighting team could be provided by monitoring the current location information and moving route information, which are received form GPS through CDMA (Code Division Multiple Access).

Factors Impacting the Work Efficiency and Stress of Case Managers with the Korea Worker's Compensation & Welfare Service (근로복지공단 사례관리자의 업무 효율 및 스트레스에 영향을 미치는 요인)

  • Lee, Su-jin;Kim, Seung Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.1
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    • pp.64-77
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    • 2022
  • Objectives: The purpose of this study is to objectify the level of case management performance and the factors influencing performance, to improve the case management performance at the Korea Worker's Compensation & Welfare Service (KWCWS) on the basis of the recognition of the objective realities of case management by job coordinators at the KWCWS, to develop a model of case management fit for the KWCWS, and to provide a basis for establishing guidelines for standardized case management. Methods: A total of 156 questionnaires were distributed to job coordinators at the KWCWS's headquarters, six regional headquarters, and 55 branches. One hundred forty-one questionnaires were collected and 126 were analyzed statistically using SPSS 21.0. Factor analysis and reliability analysis were conducted to verify the validity and reliability of the main measurement items in the research model. Frequency analysis was conducted for general characteristics of survey subjects. Frequency analysis or descriptive statistics were conducted to identify the level of independent variables (case manager's individual variables, job variables, institutional and organizational variables). Dependent variables (case management performance) and the degree of correlation were analyzed through correlation analysis between research variables. Multiple regression analysis and hierarchical regression analysis were conducted to examine the effect of independent variables on case management performance. Results: The results of the study showed that the level of overall performance in the five stages of case management was ordinary, with an average level of 3.45 on a 5-point scale. Levels of performance by step were institutional approach and intake (3.69), assessment (3.63), goal setting and intervention planning (3.46), implementation of intervention plan (3.32), and evaluation and termination (3.20), in that order. The explanatory power of case management performance (overall) by case managers with the KWCWS was case manager's institutional and organizational variables, job variables, and individual variables, in that order. At each stage of case management, the explanatory power of a case manager's institutional and organizational variables was found to be the greatest. The model changes at each stage of case management assume similar aspects statistically. In hierarchical regression analysis, it was institutional support that had a significant effect on case management performance (overall), and institutional support had the greatest effect. The results of multiple regression analysis in which all variables are input simultaneously showed that institutional support and expertise as well as self-efficacy had a positive effect. However, case management work experience, expertise (technology), and autonomy were found to have a negative effect during the stage of case management performance. Conclusions: As a result of the study, it was confirmed that raising the case manager's expertise and support from the institution and organization are important factors to improve the level of case management performance. The research also derived practical ways of reinforcement of case manager capacity, institutional and organizational support, operation of rehabilitation-case management teams, and occupational health-related aspects.

A Study on the Derivation of the Unit Hydrograph using Multiple Regression Model (다중회귀모형으로 추정된 모수에 의한 최적단위유량도의 유도에 관한 연구)

  • 이종남;김채원;황창현
    • Water for future
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    • v.25 no.1
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    • pp.93-100
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    • 1992
  • A study on the Derivation of the Unit Hydrograph using Multiple Regression Moe이. The purpose of this study is to deriver an optimal unit hydrograph suing the multiple regression model, particularly when only small amount of data is available. The presence of multicollinearity among the input data can cause serious oscillations in the derivation of the unit hydrograph. In this case, the oscillations in the unit hydrograph ordinate are eliminated by combining the data. The data used in this study are based upon the collection and arrangement of rainfall-runoff data(1977-1989) at the Soyang-river Dam site. When the matrix X is the rainfall series, the condition number and the reciprocal of the minimum eigenvalue of XTX are calculated by the Jacobi an method, and are compared with the oscillation in the unit hydrograph. The optimal unit hydrograph is derived by combining the numerous rainfall-runoff data. The conclusions are as follows; 1)The oscillations in the derived unit hydrograph are reduced by combining the data from each flood event. 2) The reciprocals of the minimum eigen\value of XTX, 1/k and the condition number CN are increased when the oscillations are active in the derived unit hydrograph. 3)The parameter estimates are validated by extending the model to the Soyang river Dam site with elimination of the autocorrelation in the disturbances. Finally, this paper illustrates the application of the multiple regression model to drive an optimal unit hydrograph dealing with the multicollinearity and the autocorrelation which cause some problems.

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CASB-DELETION DIAGNOSTICS FOR TESTING A LINEAR HYPOTHESIS ABOUT REGRESSION COEFFICIENTS

  • Kim, Myung-Geun
    • Journal of applied mathematics & informatics
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    • v.10 no.1_2
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    • pp.111-118
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    • 2002
  • We study the influence of observations on testing a linear hypothesis using single and multiple case-deletions. The change in the F-test statistic due to case-deletions is shown to be completely determined by two externally Studentized residuals. These residuals we used for investigating the outlyingness when there are linear constraints or not. An illustrative example is given. It shows the usefulness of case-deletions.

Case, Coordination, and Information Structure in Japanese

  • Ohtani, Akira;Steedman, Mark
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2007.11a
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    • pp.365-374
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    • 2007
  • This paper investigates the nature of Japanese argument cluster (Steedman 2000b). Based on Combinatory Categorial Grammar, a type-raising analysis of case particles which captures some aspects of the information structure in Japanese is discussed, including contrastive interpretation of coordination, wh-constructions, and some theme and rheme-related grammatical phenomena. These observations offer further support for the study of syntax, semantics, and phonology interface and the earlier analysis of English information structure.

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A Study on the 3 Dimensional Precision Analysis of Objects by means of Multiple Close Range Photogrammetry (다중(多重) 근거리사진측정(近距離寫眞測定)에 의한 피사체(被寫體)의 3차원(次元) 정밀해석(精密解析)에 관한 연구(硏究))

  • Kang, Joon Mook;Yeu, Bock Mo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.2
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    • pp.109-120
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    • 1985
  • This thesis is a study on multiple close range photogrammetry, and the purpose of this study is to develop the most accurate adjustment method of three dimensional object coordinates. This was achieved by comparing the standard errors of actual data to the computed values from 2 photos and multiple photos. The conventional methods for multiple photos have been analyzed by using geometric model formation. But in this study, the equation of collinearity condition which has been applied to aerial photogrammetry was derived to be a basic principle of close range photogrammetry, and the algorithm for analyzing multiple photos was developed using simultaneous bundle adjustment. The method used in this study, showed more homogeneous accuracy in coordinate and more consistent variance of error than those of conventional methods. It was found that the cases using 3, 4, and 5 photos were more accurate than using 2 photos; the accuracies were improved to 15%, 35%, and 50%, for each case. Thus this study is expected to be useful in measuring the geometry of historic monuments and other structures requiring high accuracy. Also the combined case of multiple photos is considered to be effective for the precise analysis of the objects which are difficult to measure for obstacles.

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A Study on Definition and Types of Market Entry Mode of Multiple Generation Technology: Entry Mode Cases of Semiconductor and Smartphone Market (다세대 기술 시장진입모드(Market entry mode)의 정의 및 종류에 대한 연구: 반도체 및 스마트폰 시장진입모드 사례)

  • Park, Changhyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.210-217
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    • 2020
  • Since multiple generation technology can have various entry modes by adjusting performance, price, and entry timing, understanding of market entry mode of multiple generation technology is important. This study defined the concept of market entry mode based on multiple dimensions (technology, time, performance, or price) and developed a model for various types of market entry modes. Based on a literature review, the definition and types of market entry mode were provided, and the accuracy of the model was verified based on a case study on the semiconductor and smartphone market. Six market entry modes of multiple generation technology were modeled as moderate performance and early entry, high performance and early entry, low performance and early entry, moderate performance and late entry, high performance and late entry, and low performance and late entry. This study will be useful to understand the market entry mode of multiple generation technology by defining and developing a model for entry mode and can be applied to other markets in addition to multiple generation technology.

Enhancement of UAV-based Spatial Positioning Using the Triangular Center Method with Multiple GPS

  • Joo, Yongjin;Ahn, Yushin
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.5
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    • pp.379-388
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    • 2019
  • Recently, a technique for acquiring spatial information data using UAV (Unmanned Aerial Vehicle) has been greatly developed. It is a very crucial issue of the GIS (Geographic Information System) mapping system that passes way point in the unmanned airframe and finally measures the accurate image and stable localization to the desired destination. Though positioning using DGPS (Differential Global Navigation System) or RTK-GPS (Real Time Kinematic-GPS) guarantee highly accurate, they are more expensive than the construction of a single positioning system using a single GPS. In the case of a low-priced single GPS system, the stability of the positioning data deteriorates. Therefore, it is necessary to supplement the uncertainty of the absolute position data of the UAV and to improve the accuracy of the current position data economically in the operating state of the UAV. The aim of this study was to present an algorithm enhancing the stability of position data in a single GPS mode of UAV with multiple GPS. First, the arrangement of multiple GPS receivers through the center of gravity of the UAV were examined. Next, MD (Mahalanobis Distance) is applied to detect instantaneous errors of GPS data in advance and eliminate outliers to increase the accuracy of previously collected multiple GPS data. Processing procedure for multiple GPS reception data by applying the center of the triangular method were presented to improve the position accuracy. Second, UAV navigation systems integrated multiple GPS through configuration of the UAV specifications were implemented. Using the unmanned airframe equipped with multiple GPS receivers, GPS data is measured with the TCM (Triangular Center Method). In addition, UAV equipped with multiple GPS were operated in study area and locational accuracy of multiple GPS of UAV with VRS (Virtual Reference Station) GNSS surveying were compared. The result showed that the error factors are compensated, and the error range are reduced, resulting in the reliability of the corrected value. In conclusion, the result in this paper is expected to realize high-precision position estimation at low cost in UAV using multiple low-cost GPS receivers.

Multiple-Case Studies of Hand-on Breast Massage Techniques used by Breastfeeding Experts (산후 유방 마사지 손기술에 대한 다중사례분석)

  • Park, Hyunsoon;Cho, Insook;Kim, Min-Kyeong
    • Women's Health Nursing
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    • v.23 no.3
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    • pp.155-165
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    • 2017
  • Purpose: The aim of this study was to understand the hand-on breast massage techniques used by well-known experts in breastfeeding clinics. Methods: A qualitative multiple-case design was applied that involved a feasibility test. Four experts sampling qualitative data collected by observing participants and in individual interviews were analyzed by content analysis, linking data to the propositions, and cross-case pattern matching. This study explored differences within and between cases, and the possibilities of replicating findings across cases. Thirty-nine postpartum women participated voluntarily in the feasibility test, which investigated the usability of four massage techniques. Results: The four techniques showed considerable similarities in terms of the application of stimulation to the breast base and increased flexibility of the wired flexible body, which was the core mechanism underlying the techniques. The breast management strategies were consistent with existing practice guidelines with the exception of using cold cabbage to control engorgement pain. There was insufficient scientific evidence for supporting the massage techniques used by the experts. All of the techniques showed 100% education completeness, but application rates were higher for self-control-oriented techniques. Conclusion: The massage techniques applied by experts in breastfeeding were based on hypotheses and self-control techniques are feasible to apply in practice.