• Title/Summary/Keyword: non-parametric test

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Health monitoring of a historical monument in Jordan based on ambient vibration test

  • Bani-Hani, Khaldoon A.;Zibdeh, Hazem S.;Hamdaoui, Karim
    • Smart Structures and Systems
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    • v.4 no.2
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    • pp.195-208
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    • 2008
  • This paper summarizes the experimental vibration-based structural health monitoring study on a historical monument in Jordan. In this work, and within the framework of the European Commission funded project "wide-Range Non-Intrusive Devices Toward Conservation of Historical Monuments in the Mediterranean Area", a seven and a half century old minaret located in Ajloun (73 km north of the capital Amman) is studied. Because of their cultural value, touristic importance and the desire to preserve them for the future, only non-destructive tests were allowed for the experimental investigation of such heritage structures. Therefore, after dimensional measurements and determination of the current state of damage in the selected monument, ambient vibration tests are conducted to measure the accelerations at strategic locations of the system. Output-only modal identification technique is applied to extract the modal parameters such as natural frequencies and mode shapes. A Non-linear version of SAP 2000 computer program is used to develop a three-dimensional finite element model of the minaret. The developed numerical model is then updated according to the modal parameters obtained experimentally by the ambient-vibration test-results and the measured characteristics of old stone and deteriorated mortar. Moreover, a parametric identification method using the N4Sid state space model is employed to model the dynamic behavior of the minaret and to build up a robust, immune and noise tolerant model.

The Significance Test on the AHP-based Alternative Evaluation: An Application of Non-Parametric Statistical Method (AHP를 이용한 대안 평가의 유의성 분석: 비모수적 통계 검정 적용)

  • Park, Joonsoo;Kim, Sung-Chul
    • The Journal of Society for e-Business Studies
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    • v.22 no.1
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    • pp.15-35
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    • 2017
  • The method of weighted sum of evaluation using AHP is widely used in feasibility analysis and alternative selection. Final scores are given in forms of weighted sums and the alternative with largest score is selected. With two alternatives, as in feasibility analysis, the final score greater than 0.5 gives the selection but there remains a question that how large is large enough. KDI suggested a concept of 'grey area' where scores are between 0.45 and 0.55 in which decisions are to be made with caution, but it lacks theoretical background. Statistical testing was introduced to answer the question in some studies. It was assumed some kinds of probability distribution, but did not give the validity on them. We examine the various cases of weighted sum of evaluation score and show why the statistical testing has to be introduced. We suggest a non-parametric testing procedure which does not assume a specific distribution. A case study is conducted to analyze the validity of our suggested testing procedure. We conclude our study with remarks on the implication of analysis and the future way of research development.

Analysis of Equal Sensation Curves for the Korean People about Vertical Whole-Body Vibration (앉은 자세 수직축 전신 진동에 대한 한국인의 등감각 곡선 분석)

  • Kim, Kun-Woo;Kim, Min-Seok;Yoo, Wan-Suk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.1
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    • pp.105-111
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    • 2010
  • In the field of 'Human Vibration', it has been interested subjects to make equal sensation curves related to translational and rotational direction of whole-body, hand-transmitted and head-transmitted vibration, etc. When we consider the vibration of a vehicle, the main factor is vertical whole-body vibration. Until now, most of equal sensation curves used to derive frequency weighting function had been made using Western people. However, because of the inherent differences (for example, characteristic and shape of body parts, muscular and cellular tissue) between the Western people and the Oriental people, equal sensation curves based on Oriental people might be required. Also, the weight differences between the samples which consist of average-weighted and over-weighted group might cause the difference of equal sensation curves. So, in this study, 20 male Korean people were used to find equal sensation curves subject to vertical whole-body vibration on seated posture. Among 20 males, an over weighted group consisted of 10 male persons and an average weighted group was the others. Integrating and analyzing the data of two groups, some of non-parametric tests such as 'The Wilcoxon Signed Rank Test' and 'The Mann Whitney U test' were used.

Estimating Willingness to Pay for the Tap Water Quality Improvement in Busan Using Nonparametric Approach (비모수추정법에 의한 부산시 가정용수 수질개선에 대한 지불의사액 추정)

  • Pyo, Hee-Dong;Park, Cheol-Hyung;Choo, Jae-Wook
    • Journal of Korea Water Resources Association
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    • v.44 no.2
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    • pp.125-134
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    • 2011
  • The paper is to estimate willingness-to-pay (WTP) for residential water quality improvement in Busan, using non-parametric approach. There are several significant advantages of non-parametric approach, compared to parametric methods. That is, no probability distribution assumption is necessary so that there are no needs to assume or test goodness of fit, model specification and heteroscedasticity statistically. For the reliability and the validity of contingent valuation method a survey was conducted for 665 respondents, who were sampled by stratified random sampling method, by personal interview method. The result of mean WTP for residential water quality improvement in Busan was estimated to be 3,190 won to 3,331 won per month per household, while median WTP being 1,750 won. Provided that our sample is broadly representative of the Busan's population, an estimate of the annual aggregated benefit of residential water improvement for all Busan households is approximately 50.2 billion won in case of mean WTP or 27.5 billion won in case of median WTP.

A Study on Sales Training of Clothing Companies (의류 판매원 교육실태에 관한 연구)

  • 김미숙;김보경
    • The Research Journal of the Costume Culture
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    • v.7 no.4
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    • pp.155-167
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    • 1999
  • The present study investigated various sales training programs used by apparel companies and compared each other in order to provide an important information for developing effective training programs for professional salesperson. Sixty eight companies were used and grouped into four categories based on brand characteristics : domestic national brand(DNB), casual brand(CB), foreign brand(FB) and domestic designer brand(DDB). Data were collected from the managers in charge or training salesperson by both questionnaires and personal and telephone interviews. Data were collected during July in 1998, and analyzed by using ANOVA, Duncan\`s multiple range test, and Chi-square test. Since the sample size was small, Yates\` correction formula was used to maximize statistical validity in non-parametric procedure of Chi-square test. The main purpose of sales training indicated by the companies were to satisfy customers and to maximize the profit. Significant differences were found among the groups in the importance level of training contents such as knowledge, and customer relation, training methods, place, and duration/frequency of training at training center.

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Assessment Criteria and Capability Scores for Upper Extremity Functions from Inclusive Design Perspectives

  • Kim, Taesun
    • Science of Emotion and Sensibility
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    • v.19 no.2
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    • pp.89-100
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    • 2016
  • Inclusive design is increasingly gaining attention, as some people find using products difficult after becoming physically impaired, despite daily use. However, making inclusive products is a challenge for designers or companies, as a lack of knowledge and tools stems their low involvement in it. Developing inclusive design tools is thus needed. This study developed criteria to assess upper extremity capabilities corresponding to specific daily activities. A questionnaire survey was conducted among 58 physiatrists and orthopedists. Non-parametric statistics were employed and medians were adopted as representative scores in the assessment criteria based on normality and reliability test results, non-normal data, and strong reliability of respondents in ranking. Consequently, an assessment tool was developed with 14 criteria (divided into range of motion and strength) and capability scores between 0 and 100, which discerned the moderately impaired from the severely disabled and fully capable. Since the doctors agreed to adopt the criteria but assign numeric values, especially for mild impairments, their capability assessment perception was likely influenced by dichotomy. To compensate for these deficits, qualitative or ergonomic approaches are considered simultaneously.

Relationship between dental care compliance and patients' satisfaction about dental hygienist (치과위생사에 대한 환자만족도와 치과 치료지시 이행도의 관계)

  • Kim, Seon-Yeong
    • Journal of Korean society of Dental Hygiene
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    • v.19 no.6
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    • pp.1015-1024
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    • 2019
  • Objectives: This study aimed to examine the correlation between dental care compliance and patients' satisfaction about dental hygienists who are oral health care experts likely to lead patients' motivation. Methods: From June 11 to September 30, 2019, a questionnaire survey was conducted and a total of 189 people completed a structured questionnaire evaluating patient's satisfaction and dental compliance. Data were analyzed using non-parametric tests such as Mann-Whitney test, Kruskal-Wallis rank test, and Spearman's correlation. Results: There was a statistically significant correlation between dental care compliance and the area of good impression (r=0.187, p<0.001), support for interpersonal support (r=0.346, p<0.001), and dissatisfaction (r=0.304, p<0.001). Conclusions: It is necessary to continuously study and identify ways to enhance dental care compliance and patients' satisfaction.

The Effects of a 『Traditional Play Program』 on a Child's Self-Esteem and Social Competency in a Community Child Center (『전래놀이 프로그램』이 지역아동센터 아동의 자아존중감과 사회적 능력에 미치는 영향)

  • Kim, Min-Seok;Choi, Jin-Ah
    • Korean Journal of Child Studies
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    • v.36 no.6
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    • pp.39-57
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    • 2015
  • This study aimed to confirm the usefulness of a "Traditional Play Program" in a self-esteem and social competency enrichment program at a Community Child Center. The subjects of this research comprised 12 children attending L Community Child Center in M city and participated in a "Traditional Play Program" for each 70minutes every week through total 10 sessions running from July 28th to September 29th in 2014. The collected data were analyzed by the Mann-Whitney & Wilcoxon test as non-parametric test, in addition to the progressive recording method for behavior observation. The results of this study indicate that a "Traditional Play Program" enriches the self-esteem and social competence of children who gets more vigorous activity sociality initiative respectively, and proves the usefulness for a Community Child Center.

Optimization of Micro Hydro Propeller Turbine blade using NSGA-II (NSGA-II를 이용한 마이크로 프로펠러 수차 블레이드 최적화)

  • Kim, Byung-Kon
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.4
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    • pp.19-29
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    • 2014
  • In addition to the development of micro hydro turbine, the challenge in micro hydro turbine design as sustainable hydro devices is focused on the optimization of turbine runner blade which have decisive effect on the turbine performance to reach higher efficiency. A multi-objective optimization method to optimize the performance of runner blade of propeller turbine for micro turbine has been studied. For the initial design of planar blade cascade, singularity distribution method and the combination of the Bezier curve parametric technology is used. A non-dominated sorting genetic algorithm II(NSGA II) is developed based on the multi-objective optimization design method. The comparision with model test show that the blade charachteristics is optimized by NSGA-II has a good efficiency and load distribution. From model test and scale up calculation, the maximum prototype efficiency of the runner blade reaches as high as 90.87%.

A Study on the Scheme to Activate an e-Book Service in Academic Libraries (대학도서관 전자책서비스 활성화 방안에 관한 연구 - 대출기록 분석을 중심으로 -)

  • Jung, Jin-Han
    • Journal of the Korean Society for Library and Information Science
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    • v.43 no.1
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    • pp.113-133
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    • 2009
  • This study suggests a scheme to activate an e-book service through the analysis on the cause of low usage of the services in academic libraries. The data analysis of e-book circulation records was performed for the purpose of preparing the scheme. Frequency analysis and descriptive statistics were used for basic data analysis. Also, t-test, ANOVA, non-parametric chi-square, and correlation analysis were used to examine whether there are any significant differences between treatment groups divided by gender and major.