• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.179-184
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• 2003

In order to mitigate the overcapacity of Busan port, Busan new port has been developed as transshipment port which is capable of handling 8,000 TEU containership. Generally, design of transshipment port has to reflect the capacity of feeder because both mother vessels and feeders enter the planned port at the same time. However, the existing plan of Busan new port capacity needs to be reexamined since the adopted capacity of each berth at new port, 300,000 TEU, does not seem to be enough to handle both mother vessels and feeders. Therefore, in this study we calculated the required number of berth and berth length by considering cargo handling capacity in terms of the ship size and this study makes some implications in relation with the terminal development plan.

• Journal of the Korean Society of Costume
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• v.55 no.1 s.91
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• pp.86-100
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• 2005

The purpose of this study was to investigate lifestyle of male college students and their preference of casual wear style. A questionnaire consisted of 60 lifestyle items, 1 casual wear style-preference question and demographic variables was developed. Data were collected from questionnaires distributed to male college students of 7 universities located in the Daegu${\cdot}$Gyeongbuk area during August 2003. After eliminating incomplete questionnaires, 303 were analyzed by descriptive statistics, factor analysis, cluster analysis, one-way ANOVA, and $x^2-test$. As a result of factor analysis on lifestyle items, 8 factors were determined: consumption and fashion orientation, future preparation, social concern, a wide range of thought and experience, health orientation, independent spirit, masculinity, and family orientation. 4 groups were identified on the basis of these 8 factors and named as active pragmatic group, liberal empirical group, prospective self-supporting group, and social accommodative group. Their component ratio were $30.2\%,\;33.2\%,\;19.6\%,\;and\;16.9\%$ respectively. The most preferred casual wear style by male college students was determined as basic casual wear, followed by adult casual wear, fashionable casual wear, and sporty casual wear. Other than the most preferred style, basic casual wear, by every group, the preference of casual wear styles differed among 4 lifestyle groups.

• Journal of the Korean Solar Energy Society
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• v.38 no.2
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• pp.45-53
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• 2018

For the preliminary step for estimating the performance of roof-type photovoltaic system in urban areas, we analyzed the solar radiation reduction ratio by shadow effect by buildings using DSM (Digital Surface Model) and GIS (Geographical Information System) tools. An average loss by the shadow is about 19% in Seoul. The result was related to the building density and distribution. Monthly results show that the winter season (December and January) was more affected by the shading than during the summer season (June and July). It is expected that useful empirical formulas can be made if more detailed correlation studies are performed.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.124-131
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• 2011

This study is conducted to analyze the questioning styles of the parts of chemistry in 17 middle school science textbooks in terms of frequency, types, and placement of questions. The instrument was the Textbook Questioning Strategies Assessment Instrument (TQSAI) developed by the Cooperative Teacher Preparation Program, University of California in 1975. An averaged ratio of questionings/sentences (Q/S) of seventeen textbooks was 13.6% varying from 6.8% to 19.7%. Various question types were used in titles, early and middle steps in the sections except late steps. The comprehending questions were most frequent in the types of inquiry courses and the focusing questions were most frequent in the characteristics of instructional courses. The percentages of empirical questions for the total numbers of questions were slightly larger than nonempirical questions with values of 54.2% and 45.8%, respectively.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.163-172
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• 2002

The turbine system composed of a nozzle and a rotor is used to drive turbopumps while gas passes through the nozzle, potential energy is converted to kinematic energy, which forces the rotor blades to spin. In this study, an aerodynamic design of a turbine system is investigated using compressible fluid dynamic theories with some pre-determined design requirements (i.e.,pressure ratio, rotational speed, required power etc.) obtained from a liquid rocket engine (L.R.E.) system design. For simplicity of a turbine system, impulse-type rotor blades for open type L.R.E. have been chosen. Usually, the open-type turbine system requires low mass flow rate compared to the close-type system. In this study, a partial admission nozzle is adopted to maximize the efficiency of the close-type turbine system. A design methodology of the a turbine system has been introduced. Especially, a partial admission nozzle has been designed by means of simple empirical correlations between efficiency and configuration of the nozzle. Finally, a turbine system design for a 10 ton thrust level of L.R.E is presented.

• Korea journal of population studies
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• v.30 no.2
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• pp.147-168
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• 2007

The objective of this study is to examine the studies of foreign workers in Korea at a level of meta-analysis focusing on their subjects and methodology. Over the last 15 years, studies of foreign workers have diversified subjects and refined methodology reflecting major characteristics of migration patterns including a rapid increase in number, large populations of illegal sojourners, a majority low-skilled young male workers from less developed countries, and an active role of migrant-support NGOs. Nevertheless, the studies have shown problems such as a higher ratio of macroscopic discussions, overemphasis on social problematic issues and a tendency towards descriptive analysis. Methodologically, they have also revealed an inactive use of empirical and quantitative data, lack of representativeness of sample and disregard of an importance of language in the study of foreigners. Based on the analysis, this study proposes strategies to enhance researches of foreign workers in Korea.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.205-217
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• 2007

The purpose of this paper is to measure and analyze the efficiency of management in general bank. Each bank was analyzed to find out the efficiency and classified as efficient and inefficient bank. To the inefficient bank, the inefficient part and the extent are round out, the improvement methods of efficiency are suggested, and the effects of scale of bank on management efficiency by BCC model are analyzed. And, the differences between commercial bank and local bank also are examined. Empirical main results are as follows: Frist, After 2000, both of commercial and local bank shows the continuous improvement of the management efficiency. Second, the relative efficiency of management of commercial bank is higher than local bank except 2004. Third, there are differences in variables except equity ratio and no differences appeared in the management efficiency between commercial bank and local bank. Fourth, there are no influences or negative influences by M&A and reconstruction among banks in the effect of scale to the management efficiency.

• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.67-75
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• 2002

For the design of concrete structures in the serviceability limit state, the uniaxial static modulus of elasticity may be a most important parameter. In particular, this may be so just for a deflection control of the structure. Even in new concrete codes, however, the elastic modulus is normally presented on the form of general empirical relationships with the compressive strength and density of concrete. Normally, there is a large uncertainty associated with the general equations obtained by regression. Thus, in a typical plot of static modulus of elasticity vs. compressive strength, a large scatter can be observed at same strength. The aim of this study is to present the method for obtain the maximum modulus of elasticity at same compressive strength. In the present paper report the effects of mix ingredients on the modulus of elasticity of high-strength concrete. The test of 284 cylinder specimens arc conducted for type I with 11 ％ replacement of fly-ash cement concretes. Different water-hinder ratio, amounts of water and coarse aggregate as variables were investigated. And also analyzed it statistically by using SAS.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.93-100
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• 1998

This paper presents a study on the flexural stiffness, plastic hinge length and plastic hinge rotation capacity of reinforced high performance concrete beams. 15 beams with different strength of concrete, reinforcement ratio and the pattern of loadings were tested. From the test results of reinforced normal strength concrete beams and reinforced high performance concrete beams with the concrete which has cylinder compressive strength of 700kg/${cm}^2$, slump value of 20~25cm and slump-flow value of 60~70cm. It is found that an extreme fiber concrete compressive strain of ${\varepsilon}_{cu}=0.0047$ may be used in ultimate curvature computations of reinforced high performance concrete beams. An empirical equation is proposed to estimate the effective moment of inertia. length and rotation capacity of plastic hinge of simply supported reinforced high performance concrete beams. The estimated deflections using this equation agree well with the experimental values.

• Smart Structures and Systems
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• v.11 no.4
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• pp.411-433
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• 2013

Due to its easy operation and wide applicability, the ambient vibration method is commonly adopted to determine the cable force by first identifying the cable frequencies from the vibration signals. With given vibration length and flexural rigidity, an analytical or empirical formula is then used with these cable frequencies to calculate the cable force. It is, however, usually difficult to decide the two required parameters, especially the vibration length due to uncertain boundary constraints. To tackle this problem, a new concept of combining the modal frequencies and mode shape ratios is fully explored in this study for developing an accurate method merely based on ambient vibration measurements. A simply supported beam model with an axial tension is adopted and the effective vibration length of cable is then independently determined based on the mode shape ratios identified from the synchronized measurements. With the effective vibration length obtained and the identified modal frequencies, the cable force and flexural rigidity can then be solved using simple linear regression techniques. The feasibility and accuracy of the proposed method is extensively verified with demonstrative numerical examples and actual applications to different cable-stayed bridges. Furthermore, several important issues in engineering practice such as the number of sensors and selection of modes are also thoroughly investigated.