• Title/Summary/Keyword: measurement index

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Accuracy of Data-Model Fit Using Growing Levels of Invariance Models

  • Almaleki, Deyab A.
    • International Journal of Computer Science & Network Security
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    • v.21 no.12
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    • pp.157-164
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    • 2021
  • The aim of this study is to provide empirical evaluation of the accuracy of data-model fit using growing levels of invariance models. Overall model accuracy of factor solutions was evaluated by the examination of the order for testing three levels of measurement invariance (MIV) starting with configural invariance (model 0). Model testing was evaluated by the Chi-square difference test (∆𝛘2) between two groups, and root mean square error of approximation (RMSEA), comparative fit index (CFI), and Tucker-Lewis index (TLI) were used to evaluate the all-model fits. Factorial invariance result revealed that stability of the models was varying over increasing levels of measurement as a function of variable-to-factor ratio (VTF), subject-to-variable ratio (STV), and their interactions. There were invariant factor loadings and invariant intercepts among the groups indicating that measurement invariance was achieved. For VTF ratio (3:1, 6:1, and 9:1), the models started to show accuracy over levels of measurement when STV ratio was 6:1. Yet, the frequency of stability models over 1000 replications increased (from 69% to 89%) as STV ratio increased. The models showed more accuracy at or above 39:1 STV.

Calibration Interval Analysis Method Based on F-test and Performance Index of Measurement Reliability Model Using Maintenance Data in Military Weapon Systems (군 무기체계에서 정비 데이터를 이용한 측정신뢰도 모델의 F-검정 및 성능지수 기반 교정주기 분석 기법)

  • Cha, Yun-bae;Kim, Boo-il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.11
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    • pp.2191-2198
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    • 2017
  • The PME(precision measurement equipment) used in the measurement to check the performance of the equipment in military weapon system is periodically calibrated to maintain measurement reliability during the life cycle. Previous studies suggest that reliability models are determined by considering sample size and characteristics of equipment. However, it may not be fit well to apply a single model assuming the same characteristic distribution for the maintenance date of many kinds of PMEs. This paper proposes that the most suitable calibration interval for maintenance data is selected through the F-test and the performance index evaluation among the calibration intervals estimated from the measurement reliability models assuming the characteristic of the bath-tub curve during the life cycle of various PMEs. The research results show that the reliabilities of various types of equipment are maintained during calibration intervals.

Salinity Determination Using Temperature Compensated On-Line Refractometer (온도보상형 온라인 굴절계를 이용한 해수의 염도 측정)

  • 최한욱;김영한
    • Journal of Korean Port Research
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    • v.15 no.1
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    • pp.99-105
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    • 2001
  • An on-line refractrometer made of easily obtainable materials is built to determine the salinity and temperature of sea water, and its performance is examined by applying the refractometer to known salt solution. Since refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for accurate measurement. The outcome of salinity measurement for the different concentrations of salt solution indicates that the device is suitable for the salinity measurement by yielding stable and reproducible reading.

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Effects of Skin Anti-Aging Wellness Program on Factors Related to Wellness Index and Skin Health (피부건강 웰니스 프로그램이 웰니스지수 및 피부건강지표에 미치는 영향)

  • Kim, Hyunjun
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.4
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    • pp.223-230
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    • 2019
  • Purpose : Wellness tourism is defined as travel for the purpose of promoting health and well-being through physical, psychological, or spiritual activities. The development and verification of a comprehensive wellness program for health care for workers is needed. The purpose of this study is to investigate the wellness and skin health effects of skin health programs in order to develop high-value health care services. Methods : The subjects were 15 middle-aged women who understood the research and volunteered and participated in the two-day skin health wellness program. Participants were measured to determine their wellness index and skin health twice: before and after participating in the program. Wellness index measures include comprehensive wellness, physical wellness, mental wellness, emotional wellness, social/cultural wellness, financial wellness, and environmental wellness. Skin health measurement items consisted of skin oil, skin water, skin pore, skin elasticity, skin wrinkle, and skin pigment. The skin wellness program included aerobic exercise, endurance exercise, functional food, cosmetics, herbal tea, massages, spa treatments, meditation, and marine leisure sports. The t-test analysis was used to compare the difference between wellness index and skin health measurement items before and after the program. Results : Among the wellness index items, the comprehensive wellness index (p<.05), mental wellness index (p<.05) and environmental wellness index (p<.05) showed statistically significant differences. Among skin health items, skin oil (p<.05), skin elasticity (p<.01) and skin wrinkle (p<.01) all showed statistically significant differences. There was no statistically significant difference in physical wellness, emotional wellness, social/cultural wellness, financial wellness, skin water, skin pore and skin pigment. Conclusion : This study confirmed that the two-day complex wellness program is an effective program for some items of wellness index and skin health.

A Study on the Performance Measurement Method for National Research and Development Projects (국가 연구개발(R&D) 투자의 성과 측정 방법 연구)

  • Yim, Sunjip;Kim, Sungcheol;Shin, Minsoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4148-4156
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    • 2014
  • The aim of this paper was to suggest a national R&D performance measurement index from a new perspective. Government is trying to transit the R&D paradigm from 'catch-up' into 'lead- forward'. The problem of the existing performance evaluation was first identified, and the performance evaluation method of domestic & overseas research center & government was then reviewed. In particular, this study first referred to the creation & innovation indices, and focused on the national innovation and R&D ecosystem. Next, D'Aveni's Hypercompetition theory was applied to suggest a new performance measurement index, and AHP analysis interviewed from the domestic R&D performance evaluation experts was performed. This study contributes to the new national R&D performance index for the creative economy.

Measurement of Effective Refractive Index of Nematic Liquid Crystal in Fabry-Perot Etalon

  • Ko, Myeong Ock;Kim, Sung-Jo;Kim, Jong-Hyun;Lee, Bong Wan;Jeon, Min Yong
    • Journal of the Optical Society of Korea
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    • v.19 no.4
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    • pp.346-350
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    • 2015
  • We report a measurement of the effective refractive index of a nematic liquid crystal (NLC) inside a Fabry-Perot (FP) etalon according to the applied electric fields. The effective refractive index of the NLC depends on the intensity of the applied electric field. A wavelength-swept laser with a polygon-scanner-based wavelength filter is used as a wide-band optical source to measure the effective refractive index of the NLC. The bandwidth of the optical source is greater than 90 nm around 1300 nm. The fabricated NLC FP etalon consists of glass substrates, gold layers as the electrodes with highly reflective surfaces, polyimide layers as the planar alignment layers, and an LC layer. Furthermore, we measured the Freedericksz transition voltages for three types of NLC FP etalons having thicknesses of $30.6{\mu}m$, $55.4{\mu}m$, and $108.8{\mu}m$. The Freedericksz transition voltages in the three cases are nearly equal. The measured effective refractive indices in the three cases decreased from 1.67 to 1.51 as the applied electric field intensity was increased. Beyond the threshold electric field, the effective refractive indices quickly decreased and eventually saturated at a value of 1.51 for all cases.

A Study on Organizational Performance Indicators of IT Company (IT 기업의 조직 성과 지표에 관한 연구)

  • Kim, Hyung-Sub
    • Journal of the Korea Convergence Society
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    • v.10 no.1
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    • pp.187-195
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    • 2019
  • There is a growing emphasis on objective and quantified performance measurement methodologies for the interactions that occur within modern companies. This is due to the importance of establishing and practicing future-oriented strategies by estimating the present value of the company and the current energy status through objective evaluation of the company. Therefore, the selection of KPI as a performance index using BSC (Balance Scorecard), which is a recent objective performance measurement methodology, has become very important. Although many studies on existing KPIs have been made in various industries, KPI studies on SI companies have been insufficient. This study focuses on finding KPIs applicable to SI companies. The study on the KPI design system according to general strategy of SI companies and the development of methodology and evaluation index according to index development for each group were carried out and the weighting methodology according to each evaluation index was presented.

An Overview of Pain Measurements (통증평가도구에 관한 고찰)

  • Shim, Sung-Youn;Park, Hi-Joon;Lee, Jun-Mu;Lee, Hyang-Sook
    • Korean Journal of Acupuncture
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    • v.24 no.2
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    • pp.77-97
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    • 2007
  • Objectives : The aim of this study is to introduce pain measurement tools that are considered suitable for clinical practice and research for Korean Medicine Doctors. Methods : We analysed some widely used and also useful pain measurement tools in terms of their methods and dimensions. Results : Diagrams, scales and questions are usually used to measure pain intensity, temporal pattern, treatment including exacerbating and/or relieving factors, pain location, pain interference, pain quality, pain affect, pain duration, pain beliefs and pain history. Specific pain measurements are also available for specific conditions such as Western Ontario and McMaster Universities Osteoarthritis Index, Oswestry Disability Index and Neck Disability Index. Conclusions : Faces Pain Rating Scale, numeric rating scale, visual analogue scale, McGill Pain Questionnaire and Brief Pain Inventory and commonly used pain measurements. Specific measurements should be considered depending on research topics.

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Dynamic Location Area Management Scheme Using the Historical Data of a Mobile User (이동통신 사용자의 이력 자료를 고려한 동적 위치영역 관리 기법)

  • Lee, J.S.;Chang, I.K.;Hong, J.W.;Lie, C.H.
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.05a
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    • pp.119-126
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    • 2004
  • Location management is very important issue in wireless communication system to trace mobile users' exact location. In this study, we propose a dynamic location area management scheme which determines the size of dynamic location area considering each user's characteristic. In determining the optimal location area size, we consider the measurement data as well as the historical data, which contains call arrival rate and average speed of each mobile user. In this mixture of data, the weight of historical data is derived by linear searching method which guarantees the minimal cost of location management. We also introduce the regularity index which can be calculated by using the autocorrelation of historical data itself. Statistical validation shows that the regularity index is the same as the weight of measurement data. As a result, the regularity index is utilized to incorporate the historical data into the measurement data. By applying the proposed scheme, the location management cost is shown to decrease. Numerical examples illustrate such an aspect of the proposed scheme.

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Dynamic Location Area Management Scheme Using the Historical Data of a Mobile User (이동통신 사용자의 이력자료를 고려한 동적 위치영역 관리기법)

  • Lee, J.S.;Chang, I.K.;Hong, J.W.;Lie, C.H.
    • IE interfaces
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    • v.18 no.4
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    • pp.382-389
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    • 2005
  • Location management is very important issue in wireless communication system to trace mobile users' exact location. In this study, we propose a dynamic location area management scheme which determines the size of dynamic location area considering each user's characteristics. In determining the optimal location area size, we consider the measurement data as well as the historical data, which contains call arrival rate and average speed of each mobile user. In this mixture of data, the weight of historical data is derived by linear searching method which guarantees the minimal cost of location management. We also introduce the regularity index which can be calculated by using the autocorrelation of historical data itself. Statistical validation shows that the regularity index is the same as the weight of measurement data. As a result, the regularity index is utilized to incorporate the historical data into the measurement data. By applying the proposed scheme, the location management cost is shown to decrease. Numerical examples illustrate such an aspect of the proposed scheme.