• Steel and Composite Structures
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• v.7 no.4
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• pp.279-301
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• 2007

When coupling beams are proportioned appropriately in coupled core wall (CCW) systems, the input energy from ground motions is dissipated primarily through inelastic deformations in plastic hinge regions at the ends of the coupling beams. It is desirable that the plastic hinges form at the beam ends while the base wall piers remain elastic. The strength and stiffness of the coupling beams are, therefore, crucial if the desired global behavior of the CCW system is to be achieved. This paper presents the results of nonlinear response history analysis of two 20-story CCW buildings. Both buildings have the same geometric dimensions, and the components of the buildings are designed based on the equivalent lateral force procedure. However, one building is fitted with steel coupling beams while the other is fitted with diagonally reinforced concrete coupling beams. The force-deflection relationships of both beams are based on experimental data, while the moment-curvature and axial load-moment relationships of the wall piers are analytically generated from cross-sectional fiber analyses. Using the aforementioned beam and wall properties, nonlinear response history analyses are performed. Superiority of the steel coupling beams is demonstrated through detailed evaluations of local and global responses computed for a number of recorded and artificially generated ground motions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.362-369
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• 2011

In this paper, optimal deep reactive ion etching (DRIE) process conditions for fused quartz were experimentally determined by Taguchi method, and fused quartz-based micro cantilevers were fabricated. In addition, comparative study on Q-factors of fused quartz and silicon micro cantilevers was performed. Using a silicon layer as an etch mask for fused quartz DRIE process, different 9 flow rate conditions of $C_4F_8$, $O_2$ and He gases were tested and the optimum combination of these factors was estimated. Micro cantilevers based on fused quartz were fabricated from this optimal DRIE condition. Through conventional silicon DRIE process, single-crystalline silicon micro cantilevers whose dimensions were similar to those of quartz cantilevers were also fabricated. Mechanical Q-factors were calculated to compare intrinsic damping properties of those two materials. Resonant frequencies and Q-factors were measured for the cantilevers having fixed widths and thicknesses and different lengths. The Q-factors were in a range of 64,000 - 108,000 for fused quartz cantilevers and 31,000 - 35,000 for silicon cantilevers. The experimental results supported that fused quartz had a good intrinsic damping property compared to that of single crystalline silicon.

• Journal of Information Processing Systems
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• v.6 no.4
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• pp.597-608
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• 2010

Software evolution is an ongoing process carried out with the aim of extending base applications either for adding new functionalities or for adapting software to changing environments. This brings about the need for estimating and determining the overall impact of changes to a software system. In the last few decades many such change/impact analysis techniques have been developed to identify consequences of making changes to software systems. In this paper we propose a new approach of estimating change/impact analysis by classifying change based on type of change classification e.g. (a) nature and (b) extent of change propagation. The impact set produced consists of two dimensions of information: (a) statements affected by change propagation and (b) percentage i.e. statements affected in each category and involving the overall system. We also propose an algorithm for classifying the type of change. To establish confidence in effectiveness and efficiency we illustrate this technique with the help of an example. Results of our analysis are promising towards achieving the aim of the proposed endeavor to enhance change classification. The proposed dynamic technique for estimating impact sets and their percentage of impact will help software maintainers in performing selective regression testing by analyzing impact sets regarding the nature of change and change dependency.

• Journal of Engineering Education Research
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• v.13 no.4
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• pp.122-129
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• 2010

This study was conducted to compare the self-leadership strategies and locus of control between the problem-solving styles in the Korean engineering college students. Creative problem-solving styles were identified based on the three dimensions. The results of the two-way analysis of variances indicated the main effects of problem-solving styles; each problem-solving style had unique characteristics in relation to self-leadership strategies and locus of control. There were neither main effects of sex nor interaction effects of problem-solving styles and sex. It would be useful to provide the engineering students with the specialized self-leadership training program based on the problem-solving styles.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.4
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• pp.718-726
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• 1997

The purpose of the study was to investigate the interaction effect of garment formality, Yin -Yang level, and body type of children on impression formation. The experimental materials developed for the study were a set of stimuli (8 color photographs) and a response scale (34 bipolar adjectives) and the subjects were 267 elementary school teachers in Taejon area who were responsible for the first grade students. Results were as follows; The 3 independent variables showed significant effects on impression of the 4 factors (sociability, potency, dynamics, cooperation) of impression. Since body type had interaction effects with garment formality and subject's gender, the two body types were separately analyzed. For the normal body type, only the garment formality affected on impression of cooperation factor But for the large body type, garment formality affected on impression of potency dimension, garment Yin-Yang level affected on social and dynamics dimension, and subject's gender affected on social and cooperation dimensions. The body type was the most salient variables and clothing effects for the large body type was significantly different for the normal body type. It is concluded that the results support the cognitive categorization theory on impression formation.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.8
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• pp.1196-1204
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• 2002

This research was to see if the fashion product ads are standardized or differentiated, and to find what were the determinants if any differentiation existed. The purpose of this study was to identify cultural characteristics significant on marketing fashion produce. In addition, the relative importance of product appeals between rational and emotional in the fashion ads was examined. Hofstede's(l991) three cultural characteristics dimensions such as individualism-collectivism, power distance, masculinity-femininity were used. Content analysis was applied in the study. Magazine ads of apparel, cosmetics and accessories were collected from France, Japan, Korea and the US in 1999-2000. Cultural characteristics of the fashion ads were evaluated and compared in terms of country, product type and product involvement. Also ten consumption appeals were examined for county and product type. ANOVA, Duncan test and $X^2$ test were applied to analyze data. The results were shown as follows: First, all the cultural characteristics such as individualism-collectivism, power distance, and femininity-masculinity were different among countries. Second, two product appeals were significantly different among countries. Hedonic appeals were dominant fur France and the US while those were not for Korea and Japan. Third, product involvement level had significant impact on power distance characteristic and product appeals. Ads of high involvement fashion goods showed larger power distance and more emotional appeals. In conclusion, global fashion ads should be differentiated in terms of some cultural characteristics and product appeals.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.570-581
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• 2003

The purpose of this study was to investigate competitive structure between the department store and the discount store based on consumers' purchase intention. Female consumers who purchased clothing both in the department store and the discount store participated in the study by completing questionnaires (N=533) . Data were analyzed using factor analyses, paired t-test, Cronbach's $\alpha$, and chi-square analyses. The result was as following: 1 . Overall, the department store and the discount store are competing complementarily. However, this competitive structure varied with clothing items and consumers' age. 2. As a result of factor analyses, the two retailer's service quality could be evaluated with four dimensions: price and A/S, store atmosphere and VMD, store policy, and salesperson. 3. The department store was expected to provide the highest level of service in ‘price and A/S’, ‘store atmosphere and VMD’, ‘salesperson’ whereas the discount store in ‘store policy’ 4. Respondents were classified in four groups according to how frequently they use department store and discount store as following: shopper of both retailers (68.35％), discount store shopper(20.97%), department store shopper(4.70%), shopper of neither retailer(3.97％). Each group showed differences in service satisfaction and demographic characteristics.

• Korean System Dynamics Review
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• v.12 no.4
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• pp.125-156
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• 2011

The information service management models developed thus far have put their focuses mostly on technical dimensions of information systems (IS), finding their rationale from the goods-dominant logic (GDL) that IS as goods has value in itself. Information systems, however, is nothing more than a mechanism by which value is delivered to the users. According to the service-dominant logic (SDL), value is created and determined not at the time serve is made by the providers but at the time it is consumed by the users. The users therefore should be regarded as active value creators not as passive consumers of the value delivered by the providers. Based on the service-dominant logic, DISQM (Dynamic Information Service Quality Model) is developed. DISQM's backbone is designed in causal loop diagrams referring to and reinterpreting in systems thinking the 'Parasuraman, Zeithaml & Berry's GAP Model' and 'SERVQUAL' as an operational tool for the GAP Model, and the main IS success constructs are mapped onto the model exploiting the 'DeLone & MacLean's IS Success Model'. With VENSIM simulation software, this paper also shows how DISQM works in computer-simulation settings. After confirming DISQM's validity with the base simulation run, two scenarios are developed for the exemplary purpose and tested in terms of IS quality, service quality, and net benefits from the service for the public information service. Implications from the simulation runs are also discussed.

• Journal of Biosystems Engineering
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• v.20 no.1
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• pp.3-12
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• 1995

This study was conducted to investigate the cutting mechanism of the reciprocating knife of combine harvester. The cutting operation of reciprocating knife was demonstrated through the cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of standard-type reciprocating knives were analyzed by the developed program. The results are summarized as follows : (1) For the 50mm standard reciprocating knife, the bunching area and the maximum stalk-deflection were decreased rapidly according to the increase of cutting velocity ratio by 1.0 and decreased very slowly over this ratio. But, the secondary cut was occurred at ratio of 1.0 and increased rapidly over this ratio. (2) The 76mm standard knife showed better cutting mechanism than the 50mm, in two respects : the larger cutting area per one stroke and the lower revolutional speed of crank shaft for the same cutting velocity. (3) In respect to the bunching area and the secondary cutting length, the adequate height of 50mm standard reciprocating knife was 45~50mm. (4) In order to maintain the proper cutting mechanism, the adequate cutting velocity at forward speed of 0.5㎧ to 1.2m/s was from 0.4m/s to 1.2m/s for the standard knife.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.195-200
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• 2011

A low power Hall thruster is under development for orbit maintenance of a small Earth observing satellite. Both cylindrical and annular type thrusters were manufactured and tested to characterize the performance of cylindrical Hall thrusters. Results were described through comparative analyses. Cylindrical thrusters were manufactured in two different channel diameter dimensions, 28 mm and 50 mm. Thrust, ion velocity and ion current were measured in various operating conditions. The results show that cylindrical thrusters are more efficient in mass utilization and voltage utilization, but less efficient in current utilization than annular one.