• 대한교통학회지
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• 제28권5호
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• pp.131-139
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• 2010

통행수단을 선택하는 문제는 기종점간을 운행하는 여러 교통수단 중 어떤 통행수단을 선택할 것인가를 결정하는 것이다. 현재까지 제시된 대부분의 통행수단 관련연구들은 모형의 속성이나 풀이과정, 현실 적용방법들에 관한 것으로서 수단선택시 통행수단간에 존재하는 균형(equilibrium)에 대한 연구는 거의 없는 실정이다. 즉, 통행자가 통행수단을 선택할 때 이들 수단간에 균형이 존재한다는 것으로 이는 마치 통행배정모형(traffic assignment)에서 경로선택(route choice)시 경로들간에 Wardrop의 사용자 균형(user equilibrium)이 존재하는 것처럼, 수단선택시에도 수단간에 균형이 존재할 수 있다는 것이다. 본 연구는 통행수단간에 이런 균형이 존재함을 증명하며, 국가교통DB(KTDB)자료를 이용하여 균형이 존재함을 확인한다. 또한, 본 연구에서 증명한 균형상태의 수단간 선택확률을 구하기 위한 모형과 풀이과정도 제시하는데, 제시하는 모형은 고정점이론(fixed point theorem)에 기초한다. 제시된 모형은 간단한 예제를 통하여 평가하며, 통행수단간 균형상태의 해를 도출하고 있음을 확인한다.

• Steel and Composite Structures
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• 제3권3호
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• pp.185-198
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• 2003

The concept of performance based seismic design has been gradually accepted by the earthquake engineering profession recently, in which the cost-effectiveness criterion is one of the most important principles and more attention is paid to the structural performance at the inelastic stage. Since there are many uncertainties in seismic design, reliability analysis is a major task in performance based seismic design. However, structural reliability analysis may be very costly and time consuming because the limit state function is usually a highly nonlinear implicit function with respect to the basic design variables, especially for the complex large-scale structures for dynamic and nonlinear analysis. Understanding statistical properties of the structural inelastic deformation, which is the aim of the present paper, is helpful to develop an efficient approximate approach of reliability analysis. The present paper studies the statistical properties of the maximum elastoplastic story drift of steel frames subjected to earthquake load. The randomness of earthquake load, dead load, live load, steel elastic modulus, yield strength and structural member dimensions are considered. Possible probability distributions for the maximum story are evaluated using K-S test. The results show that the choice of the probability distribution for the maximum elastoplastic story drift of steel frames is related to the mean value of the maximum elastoplastic story drift. When the mean drift is small (less than 0.3%), an extreme value type I distribution is the best choice. However, for large drifts (more than 0.35%), an extreme value type II distribution is best.

• 유통과학연구
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• 제13권3호
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• pp.79-91
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• 2015

Purpose - First, the study identifies and analyzes consumer preferences with regard to health foods and supplements. Second, it identifies and analyzes consumer preferences with regard to the properties of Vitamin C supplements. Third, in order to provide a basic data for the development of Vitamin C supplements and to measure how consumers value the properties of different Vitamin C products, a consumer survey was conducted through the choice-based conjoint model. Based on the results, the research estimates consumers' relative product-related priorities as well as price levels and willingness to pay (WTP) for different product types, and makes suggestions regarding consumer-oriented new product development and progressive directions for the successful launch of health foods and supplements. Research design, data, and methodology - This study aims to define the attributes of health foods and supplements based on several characteristics including their natural ingredients, product price, product originality, natural ingredient content, and additional functional ingredients, and makes suggestions regarding strategic market pricing and product development for health foods and supplements according to customer attitudes and characteristics. The research used choice-based conjoint analysis methodology based on the Multinomial Logic Model and collected 94 questionnaires filled out by users of Korean Vitamin C supplements. Results - Product price is the most influential factor among the five analyzed properties. When consumers buy Vitamin C products, the relative significance level of four of the examined properties is as follows: 40.9% for product price, 23.3% for product originality, 21.9% for natural ingredient content, and 13.9% for additional functional ingredients. Vitamin C content is excluded as it is not a statistically significant factor. It is interesting that supplement manufacturers and retailers consider Vitamin C content to be very important whereas consumers do not regard it as an important factor at the time of purchase. The results for the marginal willingness to pay (MWTP) for each property of Vitamin C supplements show that consumers are willing to pay an additional 11,146 Korean won for a 50% increase in the natural ingredient content. With regard to product originality, consumers are willing to pay an additional 11,301 Korean won for products manufactured in Europe than for products manufactured in China. Moreover, consumers show a greater preference for products manufactured in Korea than in Europe. However, consumers are not willing to pay more for additional Vitamin C or additional functional ingredients added to Vitamin C products. Conclusions - According to the results of consumer research on Vitamin C supplements, which represent a popular health food supplement in Korea, most Korean health food and supplement companies are not consumer- or market-oriented when developing new products. Companies gather information from either R&D specialists or sales managers and their opinions are highly reflected in new product development. The study's results will help companies recognize the importance of understanding consumers' unmet needs in advance to develop new products in the future.

• 멤브레인
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• 제17권2호
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• pp.118-123
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• 2007

Performances of fluoropolymers related to membranes manufacturing for different purposes are reviewed in the present article. In particular the main physical, mechanical and chemical properties of PVDF, ECTFE and PFSA ionomers are described in their specific applications. The excellent chemical resistance and suitable electrochemical properties make fluoropolymers an especially good choice in membranes manufacturing.

• Communications for Statistical Applications and Methods
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• 제5권3호
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• pp.895-904
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• 1998

Two stage shrinkage testimator is a kind of adaptive estimators based on a test on an initial estimate of parameter. Since weighing factor plays an important roll in assessing the properties of testimator, its choice is extremely crucial in two stage testimation. Adke, Waikar and Schuurmann(1987) proposed a testimator for the mean of an exponential distribution defined with their own weighing factor. Two alternative testimators obtained using changed weighing factors are presented, and their Mean squared error(MSE) formulae are provided in this paper. Their properties are compared with those of existing one by means of MSE.

• Advances in Computational Design
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• 제9권1호
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• pp.53-71
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• 2024

Owing to these mechanical properties, carbon nanotubes have the potential to be employed in many future devices and nanostructured materials. As an example, high Young modulus accompanied by their low density, makes them a good choice for reinforcing material in composites. Therefore, we empathize and manually derive the results which shows the utilized lemma and criterion are believed effective and efficient for aircraft structural analysis of composite and nonlinear scenarios. To be fair, the experiment by numerical computation and calculations were explained the perfectness of the methodology we provided in the research.

• 산경연구논집
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• 제7권4호
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• pp.11-16
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• 2016

Purpose - There are numerous theories for retail trade area analysis which are designed to select candidate locations for new stores. In this study, comparative analysis on the characteristics from those of the theories are shown, and the explanation for the power in consumers' store-choice behaviors and their limitations are examined. Also, plans for improving commercial sphere analysis are explored. Research design, data, and methodology - This study is based on literature reviews with normative research methodology. Among many researches regarding the analysis on the location and commercial sphere for launching a new store, researches relying on statistics are excluded in this study since they belong to the marketing research area,. Results - In the Law of retail gravitation, Huff's model multinomial logit model and etc. are mutual complementary mathematical techniques for analyzing commercial spheres and each of them has its own characteristics. These theories rely on the same hypothesis in which consumers are all believed to be behaving rationally under a similar behavioral system. However, the trial in explaining or estimating behavior of choosing a store with only a select size of the population that is objectively estimated by some major properties has limits in its credibility. Conclusion - Research on consumer's spatial behaviors can be fully illustrative and explainable when it has both quantitative approaches such as 'law of retail gravitation', 'logit model' and etc., and qualitative approaches like consumer's 'cognitive structure', 'learning status', 'image formation', 'attitude' and etc.

• Asia Marketing Journal
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• 제20권4호
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• pp.65-94
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• 2019

The purpose of this study was to analyze the brand loyalty formation by positive labeling. Affecting such factors as involvement, self-image, community engagement, preference, and choice cutback, positive labeling can be seen as one of psychological factors that shapes consumer's behavior and their decision. This study was carried out because little research was done to examine the influence of positive labeling toward brand loyalty, and also to find out the benefits that consumers can get from being labeled in positive terms. Data were collected through survey questionnaire and 151 usable responses were used. Following a series of pretests and confirmatory factor analysis helped to purify measures and verify the psychometric properties of the scale. Structural equation modeling with AMOS was used for testing of research hypotheses. The result of data analysis demonstrated the positive relationship between labeling and brand loyalty, i.e. positive labeling indirectly leads to consumers' loyalty toward a brand. Findings revealed significant relationship between involvement and emotional attachment, as well as the relationship between community engagement and choice cutback. The results gave support for the hypothesis of moderating effect of buzz on the relationship between involvement and emotional attachment, even though the hypothesis of moderating effect of distinction was rejected. Taking Apple's rivalry strategy as initial point, this study highlights the role of labeling in creating social identity. The study attempts to show the positive consequences of labeling strategy for firms that seeks ways of good competition without engaging into conflicts.

• 한국세라믹학회지
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• 제34권5호
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• pp.491-499
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• 1997

High flexible lightweight composites containing tobermorite as a main mineral is produced using various amorphous silicates, lime, cement and fibers. Here, Mechanical properties of the composites were studied by observing microstructures of hydrates and fibers. Amorphous silicates having better hydraulicity retarded the crystallization of tobermorite due to better formation of C-S-H gel in water bath curing, but, difficult conversion from C-S-H gel to tobermorite in hydrothermal reaction. In the low molar ratio of CaO/SiO2 (0.67), faster crystalization was observed dued to more impurities such as Al2O3 alkali, resulting in improving mechanical properties due to small crystal size and many contact points. It was identified that a lot of calcium silicate hydates formed at surface of pulps increase bonding strength and the crack-resistance of matrix in the composites, but decrease hardness and compressive strength. The choice of amorpous silicates having better hydraulicity, low CaO/SiO2 adding each fibers bellow about 5% in the raw mixs and lower molding pressure should be needed at improve mechanical properties of composites.

• Food Science and Biotechnology
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• 제17권4호
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• pp.728-733
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• 2008

New gluten-free food product (tarhana) was produced using rice and com flours. Chemical and sensory properties of the tarhana samples were investigated and compared with those of traditional wheat tarhana. Generally, sensory analysis results indicated that utilization of com and rice flours in tarhana resulted in acceptable soup properties in terms of some of the sensory properties. The changes in electrophoretic properties of the proteins of the tarhana samples were also studied during the tarhana production. Sodium dodecyl sulfate-polyacryamide gel electrophoresis (SDS-PAGE) results showed that relative intensities of some of the protein bands in tarhana samples generally decreased during fermentation. The decrease was more obvious at the larger molecular weight region. Corn and rice tarhana seem to be promising food products for the celiac patients who have limited choice of cereal based foods.