• Title/Summary/Keyword: T-test analysis

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Redesign of Steering Wheel Support T-beam Structure to Reduce its Vibration Using Frequency Response Function Synthesis Technique (주파수응답함수 결합법을 이용한 승용차 핸들지지 T 빔의 진동저감 재설계)

  • 변성준;박남규;박윤식
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.5
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    • pp.123-130
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    • 2001
  • The purpose of this paper is to reduce the level of idling vibration on a steering wheel. In some cases, vibration on steering wheel is amplified due to the resonance between the first natural frequency of T-beam and engine idling speed. Using SDM(structural dynamic modification) technique, T-beam is redesigned to reduce its vibration. This paper used FRF(frequency response function) synthesis technique which is entirely dependent on experiment. But this method requires lots of test efforts to enhance its reliability of design. While combining this method with an analytic method. the experimental burden, the major drawback of FRP synthesis method, can be considerably relieved. Using ana1ytic sensitivity analysis, some effective modification regions are preliminarily chosen as candidate Positions where SDM can be applied to modify T-beam\`s dynamic characteristics.

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AN ANALYSIS OF THE AERODYNAMIC CHARACTERISTICS OF A T-50 CONFIGURATION USING A PANEL CODE AND ITS VALIDATION (패널코드를 이용한 T-50 형상의 공력특성 예측 및 검증)

  • Park, S.W.;Kim, D.J.;Je, S.E.;Myong, R.S.;Cho, T.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.131-135
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    • 2006
  • The aerodynamic characteristics of a T-50 aircraft configuration are investigated by a subsonic panel method. Panel methods are best applicable to the lifting surfaces such as wings and airfoils. Source and doublets are used in the present code as a basic singularities of the panel technique. The panel method is first assessed by applying it to several benchmark problems for which other solutions and experimental data are available, such as a swept wing and wing body configuration. The prediction results are compared with experimental data and show good agreement in all cases considered. Finally, the method is applied to a T-50 aircraft configuration and excellent agreement with flight test data in lift coefficients is found.

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A Study on Ash Fusibility Temperature of Domestic Thermal Coal Implementing Thermo-Mechanical Analysis (TMA를 이용한 국내 발전용 탄의 용융점 변화에 대한 연구)

  • Lee, Soon-Ho;Lim, Ho;Kim, Sang Do;Jeon, Chung-Hwan
    • Korean Chemical Engineering Research
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    • v.52 no.2
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    • pp.233-239
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    • 2014
  • The slagging which generated from ash deposition on furnace wall and tube in boiler reduces the heat transfer efficiency and damages to safety of boiler. The slag flow behavior in boiler is affected by melting temperature which is related to ash compositions. In this study, the behavior of slag is researched by using ash fusibility test, called TMA (Thermo-Mechanical Analysis). The technique measures the percentage shrinkage as the function of temperature, T25%, T50%, T75%, T90%. These temperatures indicate different stages of melting. Then, the effect of ash chemical compositions measured from XRF (X-ray Fluorescence Spectrometer) to ash fusion temperatures is discussed. Among the chemical compositions, refractory and fluxing influence on ash fusibility is described. High levels of refractory component and limited amount of fluxing components ($Fe_2O_3$, $K_2O$, CaO) increase overall melting temperatures. High $SiO_2/Al_2O_3$ ratio decrease high melting temperatures (T75%, T90%). Meanwhile, the presence of reasonable levels of fluxing components reduces overall melting temperature. A presence of fluxing component such as $K_2O$ and CaO is found to decrease the T25% values significantly. From this research, it is possible to make a reasonable explanation and prediction of ash fusion characteristic from analysis of TMA results and ash chemical compositions.

T-Commerce Shopping Attitudes Among Female College Students - Focused on Fashion Products - (여대생들의 T-Commerce 쇼핑 태도에 관한 연구 - 패션제품을 중심으로 -)

  • Paek, Ji-Su;Noh, Jung-Eun;Jung, Hyun-Joo;Lee, Seung-Hee
    • Journal of Fashion Business
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    • v.15 no.2
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    • pp.86-95
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    • 2011
  • The purpose of this study was to examine the relationships among technology innovation (perceived ease of use, perceived ease, joyfulness), individual variables (innovation, self-efficacy), fashion variables (fashion involvement, interest in celebrity style), shopping attitudes toward fashion T-Commerce, and purchasing intention. Two hundred seven female participants in age group of 20s participated in this study. For data analysis, descriptive statistics, simple and multiple regression, and Cronbach's Alpha were used to test the research questions. As the result, first, all three variables (perceived ease of use, perceived ease, joyfulness) from technology innovation did affect on attitudes toward fashion T-Commerce. Second, individual innovation did affect positively on attitudes toward fashion T-Commerce. Third, interest in celebrity style affected positively on attitudes toward fashion T-Commerce. Finally, attitudes toward fashion T-Commerce affected positively on purchasing intention of fashion T-Commerce. Based on these results, T-Commerce fashion merchandising marketing strategies of fashion goods would be provided to fashion T-Commerce retailers or marketers.

An Analysis of Satisfaction and Utilization from the Parents' Perspective on the Application of Early Childhood Education Institutions (유아교육기관의 어플리케이션 사용에 대한 학부모 관점에서의 만족도 및 활용도 분석)

  • Rim, Jeng-Hee;Han, Sang-Kil
    • The Journal of the Korea Contents Association
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    • v.20 no.5
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    • pp.140-152
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    • 2020
  • This study analyzed the satisfaction and utilization of the institutional applications used by child-education institutions from a parent's perspective. The research target is a parent who enlisted their children in private kindergarten institution located in Gyeong-gi province and final research outcomes are 443 in total. The difference in satisfaction and utilization have been identified with demographic descriptive statistics, students t-test, and F-test statistics analysis method. First, the result of T-test on the difference in satisfaction and utilization based on parents' employment status shows that statistically significant difference was found in convenience from overall satisfaction, communication from overall utilization and child-parent relationship. Second, the F-test of differences in satisfaction and utilization showed a statistically significant difference in education utilization variables, with all variables in educational background and motivation. In terms of utilization, parents' educational background and overall utilization, and children's age were confirmed to have significant differences in communication, children's relationship, and motivation in basic life. Third, the result of multiple regression analysis shows that all predictors, including ease of use, communication, and satisfaction with educational activities, have a statistically significant impact on utilization standard variables, relative contributions showed the highest level of communication satisfaction. Therefore this paper implicates that institutional applications can maximize educational effectiveness by checking the applicability of active communication and educational activities with parents and actively communicating with parents in early childhood through various educational content applications.

A Study for Convergence Curriculum of Creative Practical Use of the Direction of Characterization of Healthcare - Centred on a University - (보건의료 특성화 방향에 대한 창의실용 융복합 교육과정을 위한 연구 - 일개 대학을 중심으로 -)

  • Choi, EunMee;Kwon, LeeSeung;Park, YeongSool;Jung, YongSik
    • Journal of Digital Convergence
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    • v.16 no.6
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    • pp.283-295
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    • 2018
  • This study is to establish the direction of special education curriculum by linking the demands of the health industry and the university curriculum. For this, we conducted a questionnaire survey for 4 months from 18 January to 9 May, 2017. Cronbach alpha coefficient was used for the reliability of the study, frequency analysis was used mainly for the contents of the study, and chi-square test, variance analysis and T test were applied to the study. Cronbach's alpha coefficient was 0.891. Variance analysis, T test and chi-square test show some significant differences. The results of this study are as follows: 35% of practitioners and 22% of convergent intellectuals are desirable in institutions. Practical needs of practitioners are creative practicality, medical policy (58%). It will be necessary to conduct a nationwide survey in the future.

A Leading Price Estimation of Jeju Flounder Producer Prices by Fish Weight and a Dynamic Influence Analysis of Market Price Impulse (중량별 제주 넙치 산지가격의 선도가격 추정 및 시장가격 충격에 대한 동태적 영향 분석)

  • SON, Jingon;NAM, Jongoh
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.1
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    • pp.198-210
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    • 2016
  • This study firstly aims to estimate a leading-price of Jeju flounders with various price-classes by fish weight and secondly plans to provide policy implications of flounder purchase projects by understanding dynamic changes and interactions among flounder producer price-classes caused by price impulses in the market. This study applies an unit root test for stability of data, uses a Granger causality test to estimate the leading-price among producer prices by fish weight, employs the vector autoregressive model to analyze statistical impacts among t-1 variables used in models, and finally utilizes impulse response analyses and forecast error variance decomposition analyses to understand dynamic changes and interactions among change rates of the producer prices caused by price impulses in the market. The results of the study are as follows. Firstly, KPSS, PP, and ADF tests show that the change rate of Jeju flounder monthly producer prices by fish weight differentiated by logarithm is stable. Secondly, the Granger causality test presents that the change rate of the 1kg flounder producer price strongly leads it of 500g, 700g, and 2kg flounder producer prices respectively. Thirdly, the vector autoregressive model indicates that the change rate of the 1kg producer price in t-1 period statistically, significantly influences it of own weight in t period and also slightly affects price change rates of other weights in t period. Fourthly, the impulse response analysis indicates that impulse responses of structural shocks for the change rate of the 1kg producer price are relatively more powerful in its own weight and in other weights than shocks emanating from price change rates of other weights. Fifthly, the variance decomposition analysis points out that the change rate of the 1kg producer price is relatively more influential than it of 500g, 700g, and 2kg producer prices respectively. In conclusion, the change rate of the 1kg Jeju flounder producer price leads the change rates of other ones and Jeju purchase projects need to be targeted to the 1kg Jeju flounder producer price as the purchase project implemented in 2014.

Assessment of VARK Learning Styles in Medical School and the Influence of Gender Status, Academic Achievement (의과대학생의 VARK 학습양식과 성별, 학년, 학업성취도간의 차이분석)

  • Yoo, Hyo Hyun;Kim, Young-Jon
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.144-152
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    • 2019
  • Learning styles are the methods of gathering, processing, interpreting, organizing the information. VARK learnig inventory is instructional preference classified according to their visual(V), aural(A), read-write(R), and/or kinesthetic(K) sensory modality preferences(SMP). Learner-centered learning is emphasized, but there are few studies on VARK learning styles in Korean medical school. The purposes of this study were to assess the student' SMPs and compare those with gender, status, and academic achievement. The subjects of study were 394 students at C Medical School and Graduate School of Medicine. For the study style test, 16 questions were used in Korean version of VARK test paper© 7.0 developed by Fleming provided on the VARK website. Academic achievement was converted into a standardized score(t score). Frequency analysis, cross analysis, and variance analysis(t-test, ANOVA) were conducted to identify learning style disposition and differences between groups. The uni-modal type was 87(22.1%) and the multimodal was 307(77.9%). Regardless of gender, quasi-modal VARK was the most preferred. There was no significant difference in learning styles by gender. The first grade in medicine was the lowest in uni-modal type(8.8%) and the highest in quasi-modal VARK type(47.8%), while the fourth grade was the highest in uni-modal type(30.7%) and the lowest in quasi-modal VARK type(19.8%) and tri-modal type(19.8%). There was no difference in academic achievement by all learning types(F=1.09, p=0.37). The knowledge about students' learning styles is helpful for instructors to apply more learner-centered teaching strategies in medical education.

Fashion Attitude and Bag Purchase Behaviors of Males in their 20s-30s (20~30대 남성의 의복태도와 가방구매에 관한 연구)

  • Kim, Jung-Woo;Jin, Sun-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.3
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    • pp.267-280
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    • 2011
  • This study examined bag purchase behaviors for male consumers based on fashion attitudes. Data research were conducted on 304 males in their 20s and 30s located in Seoul & Gyeonggi province. The SPSS 17.0 software program was used to conduct data analyses such descriptive statistics, frequency analysis, factor analysis, cluster analysis, $X^2$-test, t-test, ANOVA, and Scheffe's test as a post-hoc analysis. The results of this study were as follows: Fashion attitude was identified with four factors personality, social recognition, practicality, and dignity. Customers were segmented into three subdivisions: conspicuous, recognition of individual style, and practicality of clothing. The factors derived from the factor analysis of selection criteria included intrinsic attributes and extrinsic attributes. Males in their 30s valued the intrinsic attributes and males in their 20s valued extrinsic attributes. The group of conspicuous of clothing, valued both intrinsic and extrinsic attributes as important. The factors derived from the factor analysis of bag pursuit benefit included pursuit of fashion/economic, famous brand, quality/convenience. Males in their 20s and 30s pursued famous luxury brands and fashion attitudes had a positive relevance to the bag pursuit benefit.

The Effects of Working Conditions on Internship Satisfaction of Hotel & Restaurant Management Students (산학 실습 근무 여건이 호텔 및 외식 전공 학생들의 산학 실습 만족도에 미치는 영향 - 전북 지역을 중심으로 -)

  • Mun, Min-Kuk;Jo, Mi-Na
    • Korean journal of food and cookery science
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    • v.25 no.6
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    • pp.725-738
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    • 2009
  • The purpose of this study was to investigate the effects of working conditions on internship satisfaction. Hotel & Restaurant management students at universities in Jeonju participated in this study. Out of 156 questionnaires, 149 were analyzed using SPSS 17.0 and descriptive analysis, frequency test, factor analysis, reliability test, chi-square, t-test, ANOVA, duncan's multiple regression analysis, correlation analysis and regression analysis were used. Based on the result of the conducting factor analysis, the working conditions were classified into 2 factors: work suitability and work environment. Internship satisfaction was classified into 3 factors: internship preference, education and work satisfaction, company satisfaction. Cronbach's alpha was calculated for the reliability of the survey instrument. Consequently, the working conditions were shown to affect internship satisfaction. Among the working conditions, work suitability had a lower effect on internship satisfaction than work environment. At the resort used in this study, the salary level was high, but the level of work environment, internship preference, and company satisfaction was low. The students wanted attend an internship program at the desired place to be hired and found that it was more important to be assigned to the desired department than having a higher salary.