• Title/Summary/Keyword: fundamental variables

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Fundamental Studies on the Development of Axial-flow Combine(II) - Development of Mathematical Model of Threshing Process - (축류(軸流) 콤바인의 개발(開發)에 관(關)한 기초(基礎) 연구(硏究)(II) - 탈립과정(脱粒過程)의 수학적(數學的) 모형(模型) 개발(開發) -)

  • Lee, S.K.;Woo, J.K;Kim, S.T.
    • Journal of Biosystems Engineering
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    • v.16 no.1
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    • pp.27-36
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    • 1991
  • This study was carried out getting basic data for developing a new combine which is suitable for the cultivating situation in Korea or Southeast Asia. The relation of the amount of unthreshed grains and the axial displacement of crop in threshing process was attempted to formulate mathematically in a threshing chamber of axial-flow threshing unit. It was found that unthreshed grain is an exponetially-decaying functon of axial displacement of grains based on available data. Threshing experiments were performed to validate the mathematical model by changing various levels of pertinent variables for malting barley. Good correlation were obtained between the theoretical calculation and observed data for various test conditions, such as inclination, vane pitch, concave length, drum speed, feeding velocity, stream weight, moisture content. Therefore the model can be used for general purpose to find the amount of unthreshed grain if the mean rate of occurence of threshing of kernels(${\lambda}_{\tau}$) is properly calibrated considering some other operating conditions and crop conditions which are not involved in this analysis.

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A study on foot measurement and adult women's shoe standard size. (발의 계측과 성인여자구두의 기본치수에 관한 연구 -경상도지역의 여대생을 중심으로-)

  • 김효은
    • Journal of the Korean Home Economics Association
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    • v.24 no.3
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    • pp.43-50
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    • 1986
  • This study is toidentify what makes people uncomfortable when people wear new shoes and to gain fundamental data for establishing shoe sizes. Data materal from the 16 measurement investigation conducted on 796 college girl students shows the following. 1) More than 96% of the subjects have experienced footache when they wore new shoes. It is significant that 45.76% of the subjects answered shoe width, especially pump-lining part cause them to feel more pain in their feet than any other measurement elements. 2) According to multiple correlation analysis to know which parts of feet determine shoe size, both multiple correlation coefficient of feet length to other parts of foot and joint girth to other parts of foot show the highest of R=0.93. 3) According to the ANOVA-tested result of estimated function when both foot-length-joint girth and foot length-joint girth-foot width are independent variables in each case, the level of α〈0.001 is very significant. 4) The comparision between KS G3116 adult women's shoe size establishment table and my table in this study reveals that the cases of more increased joint girth measurements than standard joint girth measurements in KS G 3116 table are easy to find.

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Verification of the Validity of Moisture Transfer Model for Prediction of Indoor Moisture Generation Rate (실내 수증기 발생량 예측을 위한 습기 전달 모델의 검증에 관한 연구)

  • Lee, Dong-Kweon;Kim, Eui-Jong;Choi, Won-Ki;Suh, Seung-Jik
    • Journal of the Korean Solar Energy Society
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    • v.26 no.1
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    • pp.41-47
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    • 2006
  • Moisture in a building is one of the most important variables influencing building performance, human health, and comfort of indoor environment. However, there are still lacks in the knowledge of understanding the moisture problem well and controlling moisture. Accordingly, in order to provide the fundamental data to control moisture contents in the indoor air, this study was to predict moisture contents transferred through building envelopes and indoor moisture generation rate. Moisture transfer model was made by physical relations in each node, and the indoor moisture generation rate was gained by comparing the model with experimental analyses. From the study, we found out that moisture generation rate was critical and day-periodic, so that we predicted the indoor moisture content by substituting the constant value gained from the average in a day for the moisture generation rate.

Training-Effectiveness and Team-Performance in Public Organization

  • UMAR, Akmal;TAMSAH, Hasmin;MATTALATTA, M.;BAHARUDDIN, B.;LATIEF R, Abdul
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.1021-1031
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    • 2020
  • This study aims to invest in empirical relationships in a model that becomes the process of Team-Performance due to participation in practical training through causality between Training Effectiveness variables, soft-skill competence, Employee-Creativity, and team performance. This study uses a quantitative approach. The analytical tool used is structural equation modeling (SEM) using AMOS version 23 software. Accidental sampling technique is used to collect the sample. As many as 202 respondents filled up a survey questionnaire with complete and valid answers. This study's results significantly contribute to fill the gap of inadequate empirical evidence that can answer critical questions about the missing link between training and employee-performance, more specifically between training-effectiveness and team-performance. The results showed that practical training would encourage employees' soft-skill competence, improve Employee-Creativity, and improve Team-Performance. Furthermore, training-effectiveness also plays a significant role in enhancing employee-creativity and helping in optimal team-performance. This study also found that the relationship between employee-creativity and team-performance did not show positive and significant results; therefore, empirically, it did not support the hypothesis built in this study. Practical training targeted towards increasing soft-skills and creativity is a fundamental reason which not only aims to contribute toward organizational performance but also provides personal feedback for self-development.

Sensitivity Analysis for Flexural Behaviors of PSC Members (프리스트레스트 콘크리트 휨 부재의 민감도 해석)

  • Lee, Jon-Ja;Lee, Bong-Goo;Kim, Min-Joo;Lee, Yong-Hak
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.2
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    • pp.183-194
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    • 2002
  • A general procedure to evaluate the sensitivity of design variables to stresses and strains in PSC flexural members is proposed. To accomplish the purpose of this study, long-term losses including creep, shrinkage, and PS steel relaxation are formulated based on the equilibrium states of the deformed sectional geometry. Thereby, the formulation follows the basic steps which consider the fundamental formulas adopted by CEB-FIP, ACI, and KCI rather than the age adjusted effective modulus concept. Twenty-one design variable including the material and geometrical properties of concrete, nonprestressing steel and prestressing steel, and the geometry of the cross section are considered in the sensitivity analysis. The gradients of the stresses and strains needed for the sensitivity assessment are calculated in a closed format. The derived formulation is applied to the T-type section PSC beam with prestressing and nonprestressing steels for the sensitivity analysis. The analytically calculated sensitivity results are compared with those numerically calculated to ensure the validity of the proposed procedure.

Characterization of Metal-FRP Laminated Composites for Strengthening of Structures: Part-I Tensile Behavior (사회기반시설물의 내진 보강을 위한 연성재-FRP적층복합체의 역학적 거동 특성 분석: Part-I 인장 거동)

  • Park, Cheol-Woo
    • Journal of the Korean Society of Safety
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    • v.26 no.6
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    • pp.54-63
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    • 2011
  • Steel plate or FRP materials have been typically used for the seismic retrofit of civil infrastructures. In order to overcome the limitation of each retrofitting material, a composite material, which takes advantages from both metal and fiber polymer materials, has been developed. In the study herein, the composite retrofitting material consists of metal part(steel or aluminum) and FRP sheet part(glass or carbon fiber). The metal part can enhance the ductility and the FRP part the ultimate strength. As a preliminary study to investigate the fundamental mechanical characteristics of the metal-FRP laminated composite material this study performed the tensile test with various experimental variables including the number, the angle and the combination of FRP laminates. From the test results, both aluminum and steel-FRP laminate composite material showed increased fracture toughness. However, the angle and the kind of fibers should be carefully considered in conjunction with the expected loading conditions. In general, steel-FRP laminate composite showed better tensile performance in regards to the seismic retrofit purposes.

Concrete contribution to initial shear strength of RC hollow bridge columns

  • Kim, Ick-Hyun;Sun, Chang-Ho;Shin, Myoungsu
    • Structural Engineering and Mechanics
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    • v.41 no.1
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    • pp.43-65
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    • 2012
  • The primary objective of this study was to identify concrete contribution to the initial shear strength of reinforced concrete (RC) hollow columns under lateral loading. Seven large-scale RC rectangular hollow column specimens were tested under monotonic or cyclic lateral loads. The most important design parameter was column length-to-depth aspect ratio ranging between 1.5 and 3.0, and the other test variables included web area ratio, hollow section ratio, and loading history. The tests showed that the initial shear strength reduced in a linear pattern as the column aspect ratio increased, and one specimen tested under cyclic loading achieved approximately 83% of the shear strength of the companion specimen under monotonic loading. Also, several pioneering shear models proposed around the world, all of which were mainly based on tests for columns with solid sections, were reviewed and compared with the test results of this study, for their possible applications to columns with hollow sections. After all, an empirical equation was proposed for concrete contribution to the initial shear strength of RC hollow columns based on fundamental mechanics and the test results.

A Study Towards the Determinants of the Intention to Use in the Auction Web Site (경매사이트 이용의도의 결정요인에 관한 연구)

  • Son Dal-Ho;SaKong Hye-Suk
    • The Journal of Information Systems
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    • v.15 no.1
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    • pp.49-71
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    • 2006
  • With a rapid diffusion of internet, more peoples are interested in electronic commerce and the various electronic commerce types are being appeared. In these respects, the internet auction being take the more attentions at the present. Since perceived usefulness and perceived ease of use are such a fundamental driver of usage intentions, it is important to understand the determinants of this construct and how their influences change. In these respects, the web site joyfulness, the web site trust and the institutional mechanism are included as the moderating variables in our research model. A better understanding of the interactions of these factors to the usage intention to the auction site would enable us to design the organizational interventions that would increase the user acceptance and the usage of auction systems. Therefore, the goal of the present research is to extend the organizational model of auction system with TAM's perceived usefulness and perceived ease of use and the additional motivating determinants. The result showed that the web site joyfulness and the trust were the significant determinants on the the usage of auction site. However, the direction of the effect was not consistant through the cases. The model suggested in this study need to be extended with including the more sociological factors and the empirical results founded in this study are required to be verified with the extended model.

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Assessment Indexes for Activation of Urban Public Space (도시의 공공공간 활성화를 위한 평가 지표 연구)

  • Kim, Do-Gyoung;Moon, Jeong-Min
    • Journal of the Korean housing association
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    • v.24 no.3
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    • pp.109-119
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    • 2013
  • Today's urban spaces require diverse functions according to segmented social changes. Urban public space needs to be a field of mutual exchange, respect of diversity, and communication. According to these needs, an identity which reaches the public should be developed and realized. Therefore, this study is to present indexes for evaluating public space as a means to improve urban identity along with developing an awareness of possible problems. For this purpose, this study found out and analysed factors of evaluation indexes for the most fundamental public spaces which form cities in order to develop directions for deciding on indexes for public space and activation of that public space. An empirical analysis was conducted with the use of a questionnaire with evaluation indexes, reliability, and validity of properties of the space to be analysed and the evaluation items were tested. Based on the results, the study compared and analysed the differences between groups with independent variables (evaluation indexes) and general characteristics through a t-test. As a result, it was discovered that easy and safe accessibility in the use of urban parks as public space was statistically significant. Such results show that accessibility is the most significant factor in the use of parks.

An Experimental Study on the Performances of a Coupled Reactor with Catalytic Combustion and Steam Reforming for SOFC and MCFC (SOFC와 MCFC에 적용하기 위한 촉매연소-수증기 개질이 통합된 반응기의 성능에 관한 실험적 연구)

  • Ghang, Taegyu;Kim, Yongmo;Lee, Sangmin;Ahn, Kookyoung
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.4
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    • pp.364-377
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    • 2014
  • The performances of a coupled reactor in which a steam reformer and a catalytic combustor were mounted simultaneously had been investigated and compared. The combustible offgas exhausted from the anode of SOFC and MCFC were utilized as heat sources for the endothermic steam methane reforming. The catalytic combustion was used in order to burn the combustible offgas. Thermal energy released by the catalytic combustion is directly transferred to the reformer surrounding the combustor. The various operational conditions such as fuel utilization rate, steam to carbon ratio, amount of catalysts, fuel cell loads were changed. And operating variables were comprehensively identified by sensitivity analysis. The fundamental results from this experimental study show the potential abilities of the coupled reactor. Therefore the results will be of help to design and manufacture the more better coupled reactor in the future.