• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1909-1915
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• 2010

The material properties of gas turbine components change during the daily start/stop thermal cycle because of exposure to the hot combustion gas. Recently, single-crystal Ni-based superalloys have been used to manufacture many hot-gas components for gas turbines. However, the user needs to depend on the manufacturer for maintenance issues because of the lack of data required for predicting blade life and material degradation. In this study, we investigate the time-dependent degradation of first-stage blades at various operating facilities to collect the basic data for life assessment and damage analysis. The blade material is a single-crystal Ni-based superalloy, CMSX-4, and the EOH (equivalent operating hours) are 25,000 and 52,000, respectively. We prepared the test specimen directly from used blades and carried out mechanical tests and microstructural observations.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.443-453
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• 2018

Radial collector wells have been widely used for large-capacity groundwater development in riparian environments, and many empirical equations have been developed for initial estimates of groundwater yield. We compare the initial yield estimates produced by several empirical equations for the radial collector well at the Anseongcheon stream site. The results of Babac's, Kordas', and Petrovic's methods are similar to the actual yield of $6,124m^3/d$, but Milojevic's method predicts a higher yield than the observed value. The conditions under which these methods are applicable explain the observed differences between the actual and estimated yields. The applicability of empirical equations is evaluated by changing the input variables of distance from well to river, number of horizontal wells, thickness of aquifer, length of horizontal well, and hydraulic conductivity. The results indicate that the conditions under which each method is applicable must be considered carefully when estimating groundwater yield, and hydraulic conductivity must be estimated accurately.

• Journal of the Korean Society for information Management
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• v.30 no.2
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• pp.101-118
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• 2013

The purpose of this study is to reveal their satisfaction procedures from users of information service expectation-disconfirmation theory. To achieve this goal, we use the NDSLQual model to measure the quality of NDSL service. The results were as follows: First, while the expectation has a negative effect on the expectation-disconfirmation, it has a positive effect on the perceived performance. And perceived performance has a positive effect on the expectation-disconfirmation. Second, the expectation-disconfirmation has a positive effect on the overall satisfaction and loyalty. However the explanatory adequacy of the regression model is very low. Third, perceived performance has a positive effect on the overall satisfaction and loyalty. In order to increase the overall satisfaction and loyalty for NDSL, it is necessary to seek ways to improve the perceived performance and lower the expectation-disconfirmation.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.130-139
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• 2016

This study is intended to investigate what impact consumption value and subjective norm by consumers with regard to the social commerce for the foodservice to affect on the behavior of consumers. The result were as follows: first consumption value and subjective norm has positive effect on perceived usefulness, except for monetary value. Second, consumption value have positive effect on perceived ease of use, except for emotional value and subjective norm. Third, perceived ease of use has positive effects on usefulness. The last, perceived ease of use and usefulness has positive effects on reuse intention. It is to be hoped that this study provides foodservice social commerce service practitioners with guideline for establishing methodical strategies.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.17-22
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• 2003

An airship is statically unstable, because it has no wing, relatively small tails and a large hull. Hence, an accurate prediction of dynamic stability is critical. In this study, dynamic stability data of the 50m Length Airship were acquired through forced oscillation wind tunnel tests. The tests were done in Birhle Applied Research Inc's Lange Amplitude Multi-Purpose(BAR LAMP) Facility located in Germany. The tests were composed with 16 static runs and 26 dynamic runs. As results, it is obtained that dynamic characteristics of the airship depend on the sideslip angle, the angular rate and its direction as well as the angle of attack. Generally, three directional moments have damping, but the normal force, the side force, and the cross-derivatives are unstable. The dynamic derivatives are not sensitive to the control surfaces, but nonlinear to the sideslip angle.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.113-119
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• 1989

In recent years there has been a growing interest in total body, hemibody, total lymphoid irradiation. For refractory leukemia or lymphoma patients, various techniques and dose regimens were introduced, including high dose total body irradiation for destruction of leukemic or bone marrow cells and immunosuppression prior to bone marrow transplantation, and low dose total body irradiation for treatment of lymphocytic leukemia or lymphomas. Accurate provision for specified dose and the desired homogeneity are essential before clinical total body irradiation. Purposes of this paper are to discuss calibrating Cobalt Unit in 3m distance using Rando Phantom, to compare calculated dose, calibrated dose, and compensating filters for homogeneous dose distribution in the head and neck, the lung, and the pelvis. Results were following. 1. Measured dose on the lung was 6% higher than on the abdomen. Measured dose on the head (10%) and neck (18%) were higher than the abdomen because of thinness. Pelvic dose was measured 12% less than the abdomen. Those data suggest that compensating filter was essential. 2. Measured dose according to distance was 3% less than calculated dose which suggest that all doses in clinical use should be compared with calculated dose for minimizing error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2046-2053
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• 2010

This study reviewed the previous research materials and made a positive investigation to identify the structural interrelation of caddies' emotional labor, job stress and turnover intention. Some analytical findings are as follows: First, the job stress increases in proportion as the emotional labor. Second, the turnover intention is not in proportion as the frequency of emotional display or the subordinate element of the emotional labor but the degree of the emotional expression and dissonance. Third, the turnover intention is in proportion as the job stress. In other words, the higher the emotional labor, the more the job stress and turnover intention. Consequently, the caddies should be highly qualified to express themselves according to their job conditions. Also, the stronger the caddies' job stress, the more their turnover intention. It is necessary to use the leadership to relieve the job stress and motivate the caddies to have the pride. My solution will have a positive effect on lessening the job stress and turnover intention.

• Journal of Korean Library and Information Science Society
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• v.47 no.1
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• pp.243-277
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• 2016

This study aimed at analyzing the influence factors of the academic library on college's education and research performances. The researched subject was 144 colleges targeted for information disclosure by Center for Higher Education Information Disclosure. The conclusion of the present study is as follows. First, the educational performance in college showed the positive relation with 'library environment' variables except 'seating capacity per capita'. Second, the educational performance in college was positively related to the variable of 'library outcome' and particularly, it was directly influenced by circulation, visit, and interlibrary loan. Third, the research performance in college showed a positive correlation with 'library environment' variables except facility scale of library. Fourth, the research performance in college showed a positive relation with the variable of 'library outcome' and research performance excluding 'publication in domestic journals per capita' was positively influenced by 'document delivery services usage per capita' and 'commercial DB usage per capita' in common.

• Journal of Distribution Research
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• v.12 no.2
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• pp.51-78
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• 2007

This study investigates what effects both customer trust in the headquarters and perceived customer justice(interactional, procedural and distributive) in agencies have on customer loyalty to the agency via customer trust and satisfaction with the agency. The data for analysis are obtained from 266 customers who are experienced in dealing with agencies. The results show the following : first, customer perceived justice has a significant positive influence on customer trust and satisfaction with the agencies. Second, customer trust in the headquarter has a significant positive influence on customer trust with the agencies. Third, customer satisfaction with the agencies has a significant positive influence on customer trust in the particular agency Fourth, both customer trust in and satisfaction with the agencies are found to have significant positive impacts on customer loyalty to the agencies. Finally, we presented suggestions for enhancing customer loyalty to the agencies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.207-211
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• 2007

It is a quite quality concerning to control the temperature of single crystalline growth as it does when we get most of heat treating products. It is also important factor to control the temperature when we make the $Al_2O_3$(single crystalline) used to artificial jewels, glass of watches, and heat resistant transparent glasses. Thus, it is a major interest to get the proper temperature in accordance with the time process while we are making mixture of oxygen and hydrogen to have the right temperature. In this paper, we will study of electrical valve positioning system with DC-Motor for the gas mixture to improve the quality of products.