• 제목/요약/키워드: Measure theory

검색결과 989건 처리시간 0.024초

한국어판 야식증후군 측정도구의 신뢰도, 타당도 및 문항반응이론에 의한 문항분석 (Psychometric Properties and Item Evaluation of Korean Version of Night Eating Questionnaire (KNEQ))

  • 김범종;김인자;최희정
    • 대한간호학회지
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    • 제46권1호
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    • pp.109-117
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    • 2016
  • Purpose: The aim of this study was to develop a Korean version of Night Eating Questionnaire (KNEQ) and test its psychometric properties and evaluate items according to item response theory. Methods: The 14-item NEQ as a measure of severity of the night eating syndrome was translated into Korean, and then this KNEQ was evaluated. A total of 1171 participants aged 20 to 50 completed the KNEQ on the Internet. To test reliability and validity, Cronbach's alpha, correlation, simple regression, and factor analysis were used. Each item was analyzed according to Rasch-Andrich rating scale model and item difficulty, discrimination, infit/outfit, and point measure correlation were evaluated. Results: Construct validity was evident. Cronbach's alpha was .78. The items of evening hyperphagia and nocturnal ingestion showed high ability in discriminating people with night eating syndrome, while items of morning anorexia and mood/sleep provided relatively little information. The results of item analysis showed that item2 and item7 needed to be revised to improve the reliability of KNEQ. Conclusion: KNEQ is an appropriate instrument to measure severity of night eating syndrome with good validity and reliability. However, further studies are needed to find cut-off scores to screen persons with night eating syndrome.

A Novel Image Segmentation Method Based on Improved Intuitionistic Fuzzy C-Means Clustering Algorithm

  • Kong, Jun;Hou, Jian;Jiang, Min;Sun, Jinhua
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권6호
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    • pp.3121-3143
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    • 2019
  • Segmentation plays an important role in the field of image processing and computer vision. Intuitionistic fuzzy C-means (IFCM) clustering algorithm emerged as an effective technique for image segmentation in recent years. However, standard fuzzy C-means (FCM) and IFCM algorithms are sensitive to noise and initial cluster centers, and they ignore the spatial relationship of pixels. In view of these shortcomings, an improved algorithm based on IFCM is proposed in this paper. Firstly, we propose a modified non-membership function to generate intuitionistic fuzzy set and a method of determining initial clustering centers based on grayscale features, they highlight the effect of uncertainty in intuitionistic fuzzy set and improve the robustness to noise. Secondly, an improved nonlinear kernel function is proposed to map data into kernel space to measure the distance between data and the cluster centers more accurately. Thirdly, the local spatial-gray information measure is introduced, which considers membership degree, gray features and spatial position information at the same time. Finally, we propose a new measure of intuitionistic fuzzy entropy, it takes into account fuzziness and intuition of intuitionistic fuzzy set. The experimental results show that compared with other IFCM based algorithms, the proposed algorithm has better segmentation and clustering performance.

On a New Index for Research Assessment

  • Farid, Farid O.
    • Journal of Information Science Theory and Practice
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    • 제9권3호
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    • pp.56-75
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    • 2021
  • We introduce a new research assessment measure, called the research excellence index. The measure, which we denote by RE-index, accurately assesses the research performance of a researcher. The methodology used in deriving the RE-index tackles many of the flaws of popular research performance indicators such as publication counts, citation counts, and the h and g indices. A dataset is introduced, which takes advantage of the wide coverage of Scopus and the Library of Congress, and, at the same time, deals with the Scopus database depth problem. For an academic publication x, a prestige-type and length scores are assigned, and if x is published in an academic periodical publication J, the stature of J is identified through a quartile score. The three scores are used to assign a value score to every academic publication, and cited academic publications are given citation scores that encompass both cases of including and excluding self-citations. The foregoing scores are used to derive another set of scores measuring the combined qualitative and quantitative aspects of the creative work, citations of creative work, informative work and citations of informative work of a researcher. The scores take into consideration co-authorship. From these scores, two versions of the RE-index for a researcher are derived, covering the cases of including and excluding self-citations. The new measure is calculated for two mathematicians.

전원 관련 안전간호수행에 영향을 미치는 요인 (Predicting Patient Safety Behaviors of Nurses in Inter-Hospital Transfer)

  • 박선희;이태화
    • 간호행정학회지
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    • 제22권3호
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    • pp.230-238
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    • 2016
  • Purpose: The purpose of this study was to investigate predictors of nurses' patient safety behavior during inter-hospital transfer. The study was based on the Theory of Planned Behavior (TPB). Methods: A descriptive survey design was used. Data were collected with a self-administrated 39-item questionnaire completed by 111 nurses from a university hospital in Seoul, South Korea. The questionnaire was developed based on the Theory of Planned Behavior (TPB) guideline and included measure of self-reported past patient safety behaviors, intentions, attitudes, subjective norms and perceived behavioral controls. Ethical approval was granted by the hospital review board. Hierarchical regression analyses were carried out. Results: The average score of patient safety behavior was $4.21{\pm}0.63$ (5 point scale). The TPB variables explained 49.9%of the variance in patient safety behavior. Intention and subjective norm were the most significant predictors of nurses' patient safety behavior. Attitude was related to nurses' patient safety behavior. Conclusion: TPB variables predicted the nurses' patient safety behavior during inter-hospital transfer of patients except for perceived behavioral controls. The results of this study suggest that better strategies for subjective norms and intentions related to patient safety behavior will be helpful in safety culture reform.

A Study for Technique of Detecting the Real-time Route Aberrance in the Passage Route Using Ship's Domain Theory

  • Gang, Sang-Guen
    • 해양환경안전학회지
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    • 제23권3호
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    • pp.273-278
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    • 2017
  • This paper is to study a technique to detect the real-time route aberrance on the passage route using bumper area of the ship domain theory. In order to evaluate the risk of route aberrance, a quarter line was created between the center line and the outer line, and a passage route with the image line outside the outer line was designed. It calculated the real-time route aberrance with the vessel bumper area to measure the risk level on the passage route. The route aberrance using overlap bumper area was simulated through three kinds of scenario vessel at the designed passage route. In this paper, we proposed Ratio to Aberrance Risk as one of the evaluation parameter to detect the route aberrance risk at each sector in the passage route and to give the evaluation criteria of 5 levels for seafarer's navigation safety. The purpose of this work is to provide the information of the route aberrance to seafarer automatically, to make it possible to prevent the human errors of seafarer on the high risk aberrance route. As the real-time risk of route aberrance on the passage route is automatically evaluated, it was well thought that seafarer can have only a little workload in order to know the risk of route aberrance at early-time. Following the further development of this work, the techniques for detecting the real-time route aberrance will be able to use the unmanned vessel.

Difference in a venture's performance depending on the initial invested round: Focusing on absorptive capacity and a venture capital's reputation

  • 정지혜;김주희;남대일
    • 한국벤처창업학회:학술대회논문집
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    • 한국벤처창업학회 2017년도 춘계학술대회
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    • pp.49-49
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    • 2017
  • This paper provides theory and evidence on how venture capital's (VC's) investment influence on new venture (NV) performance. Despite the wealth of research on the relationship between VC's investment and NV's performance, there are conflicts about whether the VC's investment can contribute to the performance of NV and NV's market value or not. For the accurate measure of the investment effect from VC, this research explored how the venture capital's investment in each development stage affects the NV's performance. The research was based on signaling theory and the theory of information asymmetry and looked for which factors affect a NV's performance. Using a sample of 364 firms went to public from 2000 to 2007, we find NV performance increases as NV acquires initial investment of VC in the early stage of development. While NV's potential absorptive capacity moderates the main relationship positively, we find no indication that NV's realized abortive capacity and NV's reputation have significant effect on the main relationship as moderators.

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Corporate Social Responsibility and Financial Performance in Korean Retail Firms

  • Lee, Jeong-Hwan;Kang, Yun-Sik;Kim, Sang-Su
    • 유통과학연구
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    • 제16권5호
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    • pp.31-43
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    • 2018
  • Purpose - We examine how a Korean retail firm's social responsibility is related to its financial performances. The traditional view of corporation expects a negative relationship, while the stakeholder theory expects a positive one. Research design, data, and methodology - We adopt the ESG score, published by Korean Corporate Governance Service to measure the level of socially responsible activity for the Korean retail firms. The ordinary least square method is adopted to investigate this relationship. The publicly traded retail firms are examined from 2011 to 2016. Results - We find that the total ESG score is negatively related to ROE but shows no statistically significant relationship with ROA and Tobin's Q value. However, a firm's environmental score is negatively related with both of ROE and ROA. Its social score is no conclusive relationship with the performance measures. The governance score is negatively related to the value of Tobin's Q. Conclusions - This paper generally supports the traditional view of corporate theory, especially in terms of ROE. This evidence is not well aligned with the existing study for Korean corporations generally documenting positive relationships. We find almost no empirical evidence supporting the stakeholder theory of corporation in the Korean retail industry.

Endochronic simulation for viscoplastic collapse of long, thick-walled tubes subjected to external pressure and axial tension

  • Lee, Kuo-Long;Chang, Kao-Hua
    • Structural Engineering and Mechanics
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    • 제18권5호
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    • pp.627-644
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    • 2004
  • In this study, the endochronic theory was used to investigate the collapse of thick-walled tubes subjected to external pressure and axial tension. The experimental and theoretical findings of Madhavan et al. (1993) for thick-walled tubes of 304 stainless steel subjected to external pressure and axial tension were compared with the endochronic simulation. Collapse envelopes for various diameter-to-thickness tubes under two different pressure-tension loadings were involved. It has been shown that the experimental results were aptly described by the endochronic approach demonstrated from comparison with the theoretical prediction employed by Madhavan et al. (1993). Furthermore, by using the rate-sensitivity function of the intrinsic time measure proposed by Pan and Chern (1997) in the endochronic theory, our theoretical analysis was extended to investigate the viscoplastic collapse of thick-walled tubes subjected to external pressure and axial tension. It was found that the pressure-tension collapse envelopes are strongly influenced by the strain-rate during axial tension. Due to the hardening of the metal tube of 304 stainless steel under a faster strain-rate during uniaxial tension, the size of the tension-collapse envelope increases.

결함수분석법과 퍼지논리를 이용한 FMECA 평가 (FMECA using Fault Tree Analysis (FTA) and Fuzzy Logic)

  • 김동진;신준석;김형준;김진오;김형철
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1529-1532
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    • 2007
  • Failure Mode, Effects, and Criticality Analysis (FMECA) is an extension of FMEA which includes a criticality analysis. The criticality analysis is used to chart the probability of failure modes against the severity of their consequences. The result highlights failure modes with relatively high probability and severity of consequences, allowing remedial effort to be directed where it will produce the greatest value. However, there are several limitations. Measuring severity of failure consequences is subjective and linguistic. Since The result of FMECA only gives qualitative and quantitative informations, it should be re-analysed to prioritize critical units. Fuzzy set theory has been introduced by Lotfi A. Zadeh (1965). It has extended the classical set theory dramatically. Based on fuzzy set theory, fuzzy logic has been developed employing human reasoning process. IF-THEN fuzzy rule based assessment approach can model the expert's decision logic appropriately. Fault tree analysis (FTA) is one of most common fault modeling techniques. It is widely used in many fields practically. In this paper, a simple fault tree analysis is proposed to measure the severity of components. Fuzzy rule based assessment method interprets linguistic variables for determination of critical unit priorities. An rail-way transforming system is analysed to describe the proposed method.

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B-스플라인 곡면과 스칼라장 이론을 이용한 임의의 형상의 압출금형 곡면의 자동생성 (Automatic Surface Generation for Extrusion Die of Arbitrarily Shaped Section using B-spline Surfaces and Scalar Field Theory)

  • 임종훈;김광혁;유동진;양동열
    • 소성∙가공
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    • 제13권1호
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    • pp.33-38
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    • 2004
  • A new approach for the design of extrusion die surface of arbitrarily shaped section is presented. In order to generate the extrusion die surface. an automatic surface construction method based on B-spline surface and scalar field theory is proposed. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u- and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections. To verify the validity and effectiveness of the proposed method, automatic surface generation is carried out for extrusion dies of arbitrarily shaped sections.