• Structural Engineering and Mechanics
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• 제75권5호
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• pp.559-569
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• 2020

In the present study, the fracture toughness of U-shaped notches made of aluminum alloy Al7075-T6 under combined tension/out-of-plane shear loading conditions (mixed mode I/III) is studied by theoretical and experimental methods. In the experimental part, U-notched test samples are loaded using a previously developed fixture under mixed mode I/III loading and their load-carrying capacity (LCC) is measured. Then, due to the presence of considerable plasticity in the notch vicinity at crack initiation instance, using the Equivalent Material Concept (EMC) and with the help of the point stress (PS) and mean stress (MS) brittle failure criteria, the LCC of the tested samples is predicted theoretically. The EMC equates a ductile material with a virtual brittle material in order to avoid performing elastic-plastic analysis. Because of the very good match between the EMC-PS and EMC-MS combined criteria with the experimental results, the use of the combination of the criteria with EMC is recommended for designing U-notched aluminum plates in engineering structures. Meanwhile, because of nearly the same accuracy of the two criteria and the simplicity of the PS criterion relations, the use of EMC-PS failure model in design of notched Al7075-T6 components is superior to the EMC-MS criterion.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2003년도 연료전지심포지움 2003논문집
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• pp.189-192
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• 2003

In this work, we have prepared platinum catalyst by various methods, investigated fuel cell performance and compared performance with commercially available $20\%$ Pt supported on carbon (Pt/C) catalyst. We have found that Pt/C prepared by reduction of chloroplatinic acid in mixed solvent (water+ethylene glycol) gives better performance compared to that produced by reduction of aqueous chloroplatinic acid, which can be attributed to smaller catalyst particle size and lower agglomeration in the mixed solvent. We have also prepared a novel platinum electrocatalyst by depositing platinum on Nafion coated carbon powder and it shows great promise. The performance of electrode prepared using $20\%Pt$ onn Nafion coated carbon mixed with Pt/C was found to be higher than the performance of electrodes using commercially available $20\%$ Pt/C, up to a current density of about $1100mA/cm^2$. The cell voltages obtained were respectively 621 and 603mV, at a current density of: $1000mA/cm^2$, in a single cell using $0.25mgPt/cm^2$ and Nafion 10035 membrane at $80^{\circ}C$ using hydrogen/oxygen reactants at 1 atm pressure.

• Asian Pacific Journal of Cancer Prevention
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• 제17권6호
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• pp.2917-2921
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• 2016

Background: To explore factors that influence quality of life (QOL) in patients receiving breast conserving therapy (BCT). Materials and Methods: In this sequential mixed methods study, 118 women from Songklanagarind Hospital were included. We used participants' characteristics, Body Image Scale (BIS), and Functional Assessment of Cancer Therapy with the Breast Cancer Subscale (FACT-B) for analysis. The BIS transformed into presence of body image disturbance (BID). Factors that influenced QOL were determined by stepwise multiple linear regression. Forty-one participants were selected for qualitative analysis. Our female researcher performed the semi-structured interviews with questions based on the symbolic interaction theory. Final codes were analysed using thematic analysis along with investigator triangulation methods. Results: Ninety percent had early stage breast cancer with post-completed BCT, for an average of 2.7 years. The median BIS score and FACT-B score were 2 (IQR=10) and 130 (IQR=39). In the regression analysis, an age of more than 50 years and BID were significant factors. As for the value of conserved breasts, two themes emerged: a conserved breast is an essential part of a participant's life and also the representation of her womanhood; the importance of a breast is related to age. Conclusions: Body image influenced QOL in post BCT participants. The conserved breasts also lead to positive and better impact on their body image as an essential part of their life.

• 품질경영학회지
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• 제46권1호
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• pp.27-38
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• 2018

Purpose: A large number of attributes with mixed levels are often considered in the conjoint analysis. In the cases where attributes have two or three levels, we research on the efficient design of survey questionnaire to estimate all the main effect and two factor interaction effects with a reasonable size of it. Methods: To reduce the number of questions in a questionnaire, the balanced incomplete block mixed level factorial design with minimum aberration was proposed by Lim and Chung (2016). Based on the number of questions and that of the respondents in that design, D-optimality criterion is adopted to find efficient designs where the main effect and two factor interaction effects are estimated. Results: The list of the number of questions and that of the respondents in efficient designs for survey questionnaire are recommended based on the D-efficiency of each design and the proposed selection criteria for the number of both questions and the respondents. By analyzing all the respondents survey data generated by the simulation study, we find the proper model. Conclusion: The proposed methods of designing survey questionnaires seem to perform well in the sense that how often the proper model is found in a simulation study where all the respondents survey data are generated by the simulation model.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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• pp.35-38
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• 1989

The purpose of this report is to investigate and analyze development and achievement of flowing and high-strength concrete by reacy mixed concrete companies in Korea. For this purpose, the investigation was divided into three parts, i.e., superplasticizers, flowing concrete, high-strength concrete. And, they were asked to quality control manager in ready mixed concrete companies. Many researches have been carried out. And, flowing concrete is applied to field in a few case. In order to improve practical applicability of high-strength concrete and make concrete strength higher, to begin with, profound research for concrete ingredients will be needed along with presentation of methods for obtaining workability and quality assurance.

• 제어로봇시스템학회논문지
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• 제8권1호
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• pp.54-59
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• 2002

In the three-axis control of satellites by using on-board actuators, gyros are usually used to measure the attitude angles and angular rates. The gyros are operated by electronic parts and mechanical actuators. The digital components of the electronic parts consist of largely FPGA (Field Programmable Gate Array) as one of the methods for VLSI(Very Large Scale Integrated) circuit design, while the mechanical parts provide output signal directly by mechanical actuation of a spinning rotor. In this research, a mixed mode of gyro is implemented in FGA. In addition to the hardware implementation, the simulation study was conducted by using the SABER for the mixed mode simulator. Results for the practical implementation of the satellite ACS (Attitude Control System) interfaced with the data processing are also presented to validate the FPGA implementation.

• 대한임상검사과학회지
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• 제45권2호
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• pp.60-65
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• 2013

Data from repeated measurements are accomplished through repeatedly processing the same subject under different conditions and different points of view. The power of testing enhances the choice of pertinent analysis methods that agrees with the characteristics of data concerned and the situation involved. Along with the clinical example, this paper compares the analysis of the variance on ex-post tests, gain score analysis, analysis by mixed design and analysis of covariance employable for repeating measure. Comparing the analysis of variance on ex post test, and gain score analysis on correlations, leads to the fact that the latter enhances the power of the test and diminishes the variance of error terms. The concluded probability, identified that the gain score analysis and the mixed design on interaction between "between subjects factor" and "within subjects factor", are identical. The analysis of covariance, demonstrated better power of the test and smaller error terms than the gain score analysis. Research on four analysis method found that the analysis of covariance is the most appropriate in clinical data than two repeated test with high correlation and ex ante affects ex post.

• 한국산업정보학회논문지
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• 제15권3호
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• pp.59-65
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• 2010

This paper proposes a modified heuristic mixed model assembly line (MMAL) balancing algorithm that provides consistent station assignments on a model by model basis as well as on a station by station. Basically, some of single model line balancing techniques are modified and incorporated to be fit into the MMAL. The proposed algorithm is based on N.T. Thomopoulos' [8] method and supplemented with several well proven single model line balancing techniques proposed in the literature until recently. Hoffman's precedence matrix [2] is used to indicate the ordering relations among tasks. Arcus' Rule IX [1] is applied to generate rapidly a fairly large number of feasible solutions. Consequently, this proposed algorithm reduces the fluctuations in operation times among the models as well as the stations and the balance delays. A numerical example shows that the proposed algorithm can provide a good feasible solution in a relatively short time and generate relatively better solutions comparing to other three existing methods.

• 한국작물학회지
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• 제67권2호
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• pp.85-94
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• 2022

혼반용 유색 찰 현미 생산을 위해 품종의 혼합 재배 기술을 이용하면 노동력 절감과 더불어 수량증대로 인한 농가소득 향상에 도움이 될 것으로 기대 된다. 유색미의 경우 현미 색이나 품종별로 항산화 및 혈중 콜레스테롤 저하 등의 다양한 기능성 성분을 함유하고 있으며 본 연구에서는 혼반용으로 적합한 유색미 품종의 선발과 재배기술의 생력화를 위하여 유색미 혼합재배기술에 대한 연구를 수행 하였다. 유색미에 함유되어 있는 페놀화합물의 정성 및 정량분석 결과 황갈색 계열의 품종 및 자원은 Ferulic acid와 Salicylic acid 함량이 높았으며, 적미 계열의 품종 및 자원은 Ferulic acid, Gentisic acid, Catechin 함량이 높았다. 흑미 계열의 경우 Ferulic acid, Caffeic acid, Cinnamic acid 함량이 높았고 적미, 녹미 등 다른 계열의 유색미에 비해 Quercetin 함량이 높은 경향이었다. 녹색계열의 녹원찰벼의 경우 Ferulic acid, Coumaric acid 함량이 높았으며 특히 Coumaric acid 함량이 다른 계열의 유색미에 비해 높았다. 블랜딩 유색미 생산을 위해 품종을 혼합하여 재배할 경우 주당수수, 등숙율 증가로 단일품종으로 재배하는 것보다 수량이 18~20% 증수 되었으며, 혼합재배 유형 중 1품종 1열 재배에서는 녹원찰, 종자혼합 재배에서는 청풍흑향찰, 한강찰과 아랑향찰은 혼합재배 유형 모두에서 생산성이 높아지는 경향이었다.

• KIEAE Journal
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• 제10권5호
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• pp.63-69
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• 2010

Recently, by the increase of demand on Super High-rise mixed-use housing and it's advanced quality, the interest on it has been raised socially. In accordance with it, the matter of resident's health and energy efficiency has been controversial in terms of living in super high-rise housing. This study started from the idea that it is necessary to have an objective data which that has many residents in narrow space with high density. The purpose of this study are as follows; Firstly, with the quantitative data analysis on energy, it will confirm the objective information on the unclear negative idea of super high-rise mixed-use housing. Secondly, it will establish the fundamental data on the energy of super high-rise mixed-use housing by examining the characteristic of energy consumption of the complex which was built more than 5 years ago. There are 4 methods of this study. Firstly, it follows the steps of theoretical view, and defines concept to study on the characteristic of super high-rise mixed-use housing. Secondly, referring to the previous study, it provides better understanding on th stream of this research and the limit as well to guide the direction in terms of energy consumption. Thirdly, it evaluates the characteristic of monthly consumption by researching the use of electricity energy and heating energy of super high-rise mixed-use housing. The major conclusions of this study are as follows; Firstly, the heating use of apartment complex is same, which is not influenced by the type of the building. Secondly, the electricity use of super high-rise mixed-use housing is from 1,2 to 1.5 as high as the normal apartment.