• Title/Summary/Keyword: Index of Skewness

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A Study on the Kansas Marital Satisfaction Scale (결혼 만족도 척도에 관한 연구 - Kansas Marital Satisfaction Scale을 중심으로)

  • 김득성
    • Journal of Families and Better Life
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    • v.7 no.2
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    • pp.85-94
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    • 1989
  • The purpose of the study was to examine the characteristics of the Kansas Marital Satisfaction Scale(KMSS). KMSS was designed as a short and direct assessment of marital satisfaction. The scale consists of three items where respondents are directly asked how satisfied they are with their marriage, with their partner as a spouse, and with their relationship with their spouse. 1) Through item analysis, three items were significant discrimination for husbands and wives. 2) The KMSS consisted of 1 factor for husbands and wives. 3) Cronbach alpha estimates of internal consistency reliability of 93 for husband and of 89 for wives. 4) For wives, the item means between satifaction with their marriage and satisfaction with their relationsphip with their husbands were significantly different, even though the items were highly correlated. For husbands, three item means weren't significantly different. 5) The distribution of responses to the scale for husbands and wives departed si nificantly from normality in terms of skewness and kurtosis. 6) The scale was correlated, in expected directions, with the Marital Comparison Level Index (MCLI) and Marital Instability Index(MII), for husbands and wives. In conclusion, the scale offers promise for use in clinical evaluation and survey research where a brief but reliable measure of marital satisfaction is required.

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A Study on a Measure for Non-Normal Process Capability (비정규 공정능력 측도에 관한 연구)

  • 김홍준;김진수;조남호
    • Proceedings of the Korean Reliability Society Conference
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    • 2001.06a
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    • pp.311-319
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    • 2001
  • All indices that are now in use assume normally distributed data, and any use of the indices on non-normal data results in inaccurate capability measurements. Therefore, $C_{s}$ is proposed which extends the most useful index to date, the Pearn-Kotz-Johnson $C_{pmk}$, by not only taking into account that the process mean may not lie midway between the specification limits and incorporating a penalty when the mean deviates from its target, but also incorporating a penalty for skewness. Therefore we propose, a new process capability index $C_{psk}$( WV) applying the weighted variance control charting method for non-normally distributed. The main idea of the weighted variance method(WVM) is to divide a skewed or asymmetric distribution into two normal distribution from its mean to create two new distributions which have the same mean but different standard distributions. In this paper we propose an example, a distribution generated from the Johnson family of distributions, to demonstrate how the weighted variance-based process capability indices perform in comparison with another two non-normal methods, namely the Clements and the Wright methods. This example shows that the weighted valiance-based indices are more consistent than the other two methods In terms of sensitivity to departure to the process mean/median from the target value for non-normal process.s.s.s.

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Bit-Vector-Based Space Partitioning Indexing Scheme for Improving Node Utilization and Information Retrieval (노드 이용률과 검색 속도 개선을 위한 비트 벡터 기반 공간 분할 색인 기법)

  • Yeo, Myung-Ho;Seong, Dong-Ook;Yoo, Jae-Soo
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.7
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    • pp.799-803
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    • 2010
  • The KDB-tree is a traditional indexing scheme for retrieving multidimensional data. Much research for KDB-tree family frequently addresses the low storage utilization and insufficient retrieval performance as their two bottlenecks. The bottlenecks occur due to a number of unnecessary splits caused by data insertion orders and data skewness. In this paper, we propose a novel index structure, called as $KDB_{CS}^+$-tree, to process skewed data efficiently and improve the retrieval performance. The $KDB_{CS}^+$-tree increases the number of fan-outs by exploiting bit-vectors for representing splitting information and pointer elimination. It also improves the storage utilization by representing entries as a hierarchical structure in each internal node.

Three-Parameter Gamma Distribution and Its Significance in Structural Reliability

  • Zhao, Yan-Gang;Alfredo H-S. Ang
    • Computational Structural Engineering : An International Journal
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    • v.2 no.1
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    • pp.1-10
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    • 2002
  • Information on the distribution of the basic random variables is essential for the accurate evaluation of structural reliability. The usual method for determining the distribution is to fit a candidate distribution to the histogram of available statistical data of the variable and perform appropriate goodness-of-fit tests. Generally, such candidate distributions would have two parameters that may be evaluated from the mean value and standard deviation of the statistical data. In the present paper, a-parameter Gamma distribution, whose parameters can be directly defined in terms of the mean value, standard deviation and skewness of available data, is suggested. The flexibility and advantages of the distribution in fitting statistical data and its significance in structural reliability evaluation are identified and discussed. Numerical examples are presented to demonstrate these advantages.

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Heuristic Process Capability Indices Using Distribution-decomposition Methods (분포분할법을 이용한 휴리스틱 공정능력지수의 비교 분석)

  • Chang, Youngsoon
    • Journal of Korean Society for Quality Management
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    • v.41 no.2
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    • pp.233-248
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    • 2013
  • Purpose: This study develops heuristic process capability indices (PCIs) using distribution-decomposition methods and evaluates the performances. The heuristic methods decompose the variation of a quality characteristic into upper and lower deviations and adjust the value of the PCIs using decomposed deviations in accordance with the skewness. The weighted variance(WV), new WV(NWV), scaled WV(SWV), and weighted standard deviation(WSD) methods are considered. Methods: The performances of the heuristic PCIs are investigated under the varied situations such as various skewed distributions, sample sizes, and specifications. Results: WV PCI is the best under the normal populations, WSD and SWV PCIs are the best under the low skewed populations, NWV PCI is the best under the moderate and high skewed populations. Conclusion: Comprehensive analysis shows that the NWV method is most adequate for a practical use.

Effects of High-harmonic Components on the Rayleigh Indices in Multi-mode Thermo-acoustic Combustion Instability

  • Song, Chang Geun;Yoon, Jisu;Yoon, Youngbin;Kim, Young Jin;Lee, Min Chul
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.4
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    • pp.518-525
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    • 2016
  • This paper presents the characteristics of non-fundamental multi-mode combustion instability and the effects of high-harmonic components on the Rayleigh criterion. Phenomenological observations of multi-harmonic-mode dynamic pressure waves regarding the intensity of harmonic components and the source of wave distortion have been explained by introducing examples of second- and third-order harmonics at various amplitudes. The amplitude and order of the harmonic components distorted the wave shapes, including the peak and the amplitude, of the dynamic pressure and heat release, and consequently the temporal Rayleigh index and its integrals. A cause-and-effect analysis was used to identify the root causes of the phase delay and the amplification of the Rayleigh index. From this analysis, the skewness of the dynamic pressure turned out to be a major source in determining whether multi-mode instability is driving or damping, as well as in optimizing the combustor design, such as the mixing length and the combustor length, to avoid unstable regions. The results can be used to minimize errors in predicting combustion instability in cases of high multi-mode combustion instability. In the future, the amount of research and the number of applications will increase because new fuels, such as fast-burning syngases, are prone to generating multi-mode instabilities.

Efficient 3D Model Retrieval using Discriminant Analysis (판별분석을 이용한 효율적인 3차원 모델 검색)

  • Song, Ju-Whan;Choi, Seong-Hee;Gwun, Ou-Bong
    • 전자공학회논문지 IE
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    • v.45 no.2
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    • pp.34-39
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    • 2008
  • This study established the efficient system that retrieves the 3D model by using a statistical technique called the function of discriminant analysis. This method was suggested to search index, which was formed by the statistics of 128 feature vectors including those scope, minimum value, average, standard deviation, skewness and scale. All of these were sampled with Osada's D2 method and the statistics as a factor effecting a change turned the value of discriminant analytic function into that of index. Through the primary retrieval on the model of query, the class above the top 2% was drawn out by comparing the query with the index of previously saved class from the group of same models. This method was proved an efficient retrieval technique that saved its procedural time. It shortened the retrieval time for 3D model by 57% faster than the existing Osada's method, and the precision that similar models were found in the first place was recorded 0.362, which revealed it more efficient by 44.8%.

An Empirical Study on Career Maturity, Achievement Goal, Learning Attitude and Academic Achievement of Middle School Students : Focused on Subjects-Related Career Education (중학생의 진로성숙도와 성취 목표, 학습 태도 및 학업성취도 실증적 고찰 : 교과연계 진로교육 경험을 중심으로)

  • Hahm, Seung-Yeon
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.5
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    • pp.616-626
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    • 2012
  • The purpose of this study is to verify career maturity, achievement goal, learning attitude and academic achievement relation with subjects-related career education of middle school students. To achieve these aims, this study used SELS(Seoul education longitudinal study) of Seoul Education Research & Information Institute. Also, analysis as well as descriptive statistics calculation on average, deviation, skewness and kurtosis of variable factor and calculated characteristic item and degree of reliability(Cronbach ${\alpha}$). For goodness of fit test, this study used TLI(Tucker-Lewis index) and RMSEA(Root mean square error of approximation). To achieve the ultimate objects, this study used LMA(latent mean analysis) for analysis of difference career maturity, achievement goal, learning attitude and academic achievement relation with subjects-related career education in middle school students. The results are as follows. First, experience relation with subjects-related career education were influenced on career maturity with career cognition. Second, experience relation with subjects-related career education were influenced on achievement goal, learning attitude, and larger than career maturity and academic achievement. Third, experience relation with subjects-related career education were influenced on middle school students more than inexperienced relation with subjects-related career education.

The Effect of Managerial Ownership on Stock Price Crash Risk in Distribution and Service Industries

  • RYU, Haeyoung;CHAE, Soo-Joon
    • Journal of Distribution Science
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    • v.19 no.1
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    • pp.27-35
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    • 2021
  • Purpose: This study is to investigate the effect of managerial ownership level in distribution and service companies on the stock price crash. The managerial ownership level affects the firm's information disclosure policy. If managers conceal or withholds business-related unfavorable factors over a long period, the firm's stock price is likely to plummet. In a similar vein, management's equity affects information opacity, and information asymmetry affects stock price collapse. Research design, data, and methodology: A regression analysis is conducted using the data on companies listed on the Korea Composite Stock Price Index (KOSPI) between 2012-2017 to examine the effect of the managerial ownership level on stock price crash risks. Results: Logistic and regression results indicate that the stock price crash risk was reduced as managerial ownership levels are increased. The managerial ownership level has a significant negative coefficient on stock price crash risk, negative conditional return skewness of firm-specific weekly return distribution, and asymmetric volatility between positive and negative price-to-earnings ratios. Conclusions: As the ownership and management align, the likeliness of withholding business-related information is reduced. This study's results imply that the stock price crash risk reduces as the managerial ownership level increases because shareholder and manager interests coincide, thereby reducing information asymmetry.

Development and Validation of S.T.E.P+ Diagnostic Tool: Assessing Organizational Competence for Self-management in Daycare Centers (어린이집 자율관리를 위한 조직역량 진단도구(S.T.E.P+)의 개발 및 타당화)

  • Jeong-Won Kang;So-Young Park;Won-Seon Lee;Yoe-Jeong Lim
    • Korean Journal of Childcare and Education
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    • v.20 no.2
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    • pp.105-126
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    • 2024
  • Objective: The study aimed to develop and validate a tool for assessing daycare center organizational competence and for autonomously managing childcare quality. Methods: Through literature review and expert reviews, items were derived and validated using the Content Validity Index. Data from a survey involving 216 directors and 509 teachers were analyzed using SPSS and AMOS to assess reliability and conduct confirmatory factor analysis. Results: Results revealed a 36-item diagnostic tool across four subcategories: shared values (6 items), training abilities (18 items), environmental support (6 items), and organizational promotion (6 items). A diagnostic tool named S.T.E.P+ was developed, named after the first letters of the four subfactors. Skewness and kurtosis were within normality assumptions. Good fit indices (CFI, TLI) and low SRMR and RMSEA values indicated a satisfactory model fit. Cronbach's α values showed high reliability for all factors. The tool enables autonomous diagnosis of childcare quality. Conclusion/Implications: This tool can effectively autonomously diagnose whether a daycare center is providing quality childcare.