• Proceedings of the KSR Conference
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• 2011.05a
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• pp.263-268
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• 2011

There are many exclusive freight cars in railway freight transportation system. Gondola is one kind of freight cars. Gondolas have a role to carry bulk-type cargo such as coals and ores. A few problems are occurring due to exclusive freight cars. Operation company has redundant freight cars because exclusive freight cars can carry limited items. And purchasing cost of freight cars is higher and higher because of irregular bid. Operation efficiency of gondola is very low because return time of gondola is much longer than that of container car. In this study, we analysed the introduction effect of hopper-type container for through transit. First, we identified the characteristics of spatial distribution on freight stations. And we provided the effect of hopper-type container in terms of operation efficiency, cost reduction, new demand excavation and image enhancement of eco-friendly railroad.

• Structural Engineering and Mechanics
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• v.10 no.3
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• pp.277-288
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• 2000

The present paper, deals with the dynamic analysis of a thin-walled tower with varying cross-section and additional masses. It, especially, deals with the effect of the rotary inertia of those masses, which have been neglected up to now. Using Galerkin's method, we can find the spectrum of the eigenfrequencies and, also, the shape functions. Finally, we can solve the equations of the problem of the forced vibrations, by using Carson-Laplace's transformation. Applying this method on a tall mast with 2 concentrated masses, we can examine the effect of the rotary inertia and the diaphragmatic operation of the above masses, on the 3 first eigenfrequencies.

• Journal of the Korean Society of Food Culture
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• v.25 no.3
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• pp.312-323
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• 2010

The objective of this study was to examine the effects of relationships between food service companies and their client companies by surveying employees working at cafeterias among a food service companies' client companies. For this purpose, previous research was reviewed, and confirmatory research was conducted using a questionnaire. In the questionnaire survey, the subjects were sampled through convenience sampling from the client companies of A Food Service Company, and 182 valid questionnaires were used in the analysis. The results of this study are summarized as follows. First, the characteristics of the relationship between the food service company and its client companies, which were reputation, communication, operation skill, and contact-point employees' service quality, had a significant effect on trust, and the effect was high in the order of contact-point employees' service quality, communication, operation skill, and reputation. Satisfaction was significantly affected by reputation, operation skill, and contact-point employee' service quality, but not by communication. The effect was high in the order of contact-point employees' service quality, reputation, and operation skill. In addition, reputation, communication, operation skill, and contact-point employees' service quality had a significant effect on long-term orientation, and the effects were high in the order of reputation, contact-point employees' service quality, communication, and operation skill. Second, with regard to the quality of relationships between a food service company and its client companies, trust had a significant effect on satisfaction. Third, among the factors related to the quality of relationships between the food service company and its client companies, trust and satisfaction had a significant effect on long-term orientation, and the effect of satisfaction was higher than that of trust. This study has scientific significance as one of only a few studies on factors affecting the long-term relationship between food service companies and their client companies, along with managerial implications that contact-point employees' capabilities are most important in service businesses, and thus efforts should be made at employing and educating them properly.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.247-263
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• 2018

In this article, it is that have highlighted the importance of the creative communication, convergence and identity of airport operations. This research verifies to influence in the airport performance by the diversity, mediator effect of creativity, and moderator effect of the public enterprise management evaluation performed degree in the operation of the airport. This study design how participants were selected as study the employees from two airports on the enterprise of the Incheon International Airport, Gimpo International Airport in Korea using the simple random sampling method. The findings indicate that the positively internal diversity, mediated creativity, and moderated public enterprise management evaluation performed degree affects performance of airports. This research provides a few implications and insights in the operation of airport.

• Journal of the Korean Solar Energy Society
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• v.39 no.4
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• pp.69-77
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• 2019

Among the main functions of the grid-connected photovoltaic (PV) system, the anti-islanding operation function is a very important problem. Recently, due to the improvement in power generation efficiency and the maintenance advantages in PV system, the use of string inverter has increased so that the possibility of islanding operation has been raised. Generally, when a power system faults, the PV inverter must be disconnected from power system within 10 cycles by the anti-islanding operation function. However, in the real-time of power system, the output power of the PV system within 10cycles is effected. In this paper, we analyzed the effect of grid-connected PV system on power quality in a short time within 10 cycles on fault case of power system using the Matlab Simulink program.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.81-85
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• 2011

The end effect of a linear induction motor (LIM) has been known for several decades, especially in high speed operation. The exit part of the primary is not dealt as extensively as the entry part because of its minor effect. However, the exit part is one of the keys to weaken the dolphin effect, which occurs in high speed operation. In this paper, the concept of the virtual primary core is introduced, and chamfering of the primary outlet teeth is proposed to minimize the longitudinal end effect at the exit zone. For this, LIM for the high-speed train is designed and analyzed by using finite element method. Results confirm that chamfering can improve thrust performance effectively.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.209-214
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• 2007

This study is concerned with working hardening of bending operation on hydroforming parts. Generally, hydroforming parts having the complicated shape of the automobile, require a 3-dimentional bending operation. This operation involves several variations in the tube which are the thickness, the mechanical characteristics, the hardness, the circumference etc., on original tube. So, we study those variations and the affect on the hydroforming operation and hydroforming parts. We used two methods, one of which was computer simulation and the other the actual test in the plant.

• The Journal of Korean Physical Therapy
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• v.16 no.2
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• pp.72-89
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• 2004

The purposes of this study were to test the effect of balance training and environmental enrichment on motor performance after traumatic cerebellar injury in the rat. Traumatic cerebellar injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. Twenty two Sprague-Dawley rats were randomly assigned into control and experimental groups. The control group was housed in standard cage for 7 days. The experimental group I was housed in standard cage after balance training for 7 days. The experimental group II was housed in environmental enrichment cage after balance training for 7 days. Vestibular drop test and tilting plane test was examined at preoperation, on 1st day after operation and 7th day after operation to the rats. The results of this experiment were as follows: 1. In motor behavioral test, at preoperation and on 1 day after operation, the outcomes were not different among the groups. But on 7th day after operation, the outcomes of group I were better than that in control group, and group II were better than group I. These results suggest that behavioral motor outcome by simultaneously application of balance training and environmental enrichment in traumatic cerebellar injured rats were more improve than that by just balance training.

• Journal of Distribution Science
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• v.20 no.9
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• pp.11-21
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• 2022

Purpose: Many concerns have appeared in banking sector in the digital era and one of them is that technology development will increase operation costs of banks. Motivated by this issue, our study aims to explore the effect of technological and digital investments on cost-effectiveness of banking operation. Research design, data and methodology: To reach a clear answer, we use the data of 12 commercial banks spanning from 2011 to 2020 in Vietnam and employ multivariate regression analysis as well as perform various robustness tests. Results: Our regression result indicates that the adverse effect of technological spending on cost-effective operation. This finding still remains unchanged when we conduct different robust tests. Also, we find that this negative impact becomes more evident in large banks than in small ones. Conclusions: The paper provides one of the most important empirical results for mangers and policy-makers in banking sphere, especially in Vietnam where regulators have been calling for continuously investing into technological innovation in banks. The evidence confirms that banks should carefully consider an increase in spending on distribution information and communication technologies when constructing business strategies related to expanding digitalization. Our research is also useful for countries having similar financial structure to Vietnam.

• Membrane and Water Treatment
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• v.13 no.1
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• pp.39-49
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• 2022

Seawater desalination is doubtlessly a viable option to supply fresh drinking water. Nevertheless, RO (reverse osmosis) desalination plants in specific areas may be intermittently operated to match the imbalance between water demand and supply. Although a handful of works have been done on other membrane systems, few studies have attempted to mitigate fouling in intermittent RO systems. Accordingly, the objectives of this paper were to examine the effect of the intermittent operation on RO fouling; and to compare four intermittent operation modes including feed solution recirculation, membrane storage in the feed solution, deionized water (DI) recirculation, and membrane storage in DI water. Results showed that intermittent operation reduced RO fouling under several conditions. However, the extents of fouling mitigation were different depending on the feed conditions, foulant types, and membrane lay-up methods. When the feed solution was recirculated during the lay-up, the restoration of the flux was less significant than that by the feed solution feed-up. The use of deionized water during the lay-up was effective to restore flux, especially when the feed solution contains scale-forming salts (CaSO₄) and/or colloidal silica.