• Journal of Drive and Control
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• v.14 no.4
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• pp.1-8
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• 2017

The Down-the-Hole hammer is one of the pneumatic drill equipment used for grinding, drilling, and mining. One the advantages of which is that a reduction work efficiency at deep site are relatively small compared to other drilling methods. Due to the large vibration in the underground area, it is difficult to measure the performance of the hammer, and hammer testing requires substantial production cost and operating expenses so research on the development of the hammer is insufficient. Therefore, this study has developed a dynamic simulation model that apprehends the operating principles of an 8-inch DTH hammer and calculates performance data such as performance impact force, piston speed, and BPM. By using the simulation model, design factors related to strike force and BPM were selected, and the influence of each design factors on performance was analyzed through ANOVA analysis. As a result, be the most important for BPM and the strike force are position of upper port that push the piston in the direction of the bit and in BPM, the size of the empty space between the bits and the piston is the second most important design factor.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.473-479
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• 2017

This study is to analyze differences in gross income between only forestry and agroforestry. In addition, cost structure and management performance on poultry farming was surveyed. The study sites were three forestry households located in Chungju, Kyungsan and Hwacheon. The method of its management performance were conducted by interview. And, survey items of the performance were operating expenses items and gross income items in 2015. As a result of study, gross income of Chungju business model was 25,608,000 won. The operating cost was 20,217,571 won so that the net income was 5,390,429 won. In case of Gyeongsan, gross income was 33,950,000 won and the operating cost was 18,655,714 won. Thus, the net income was 15,494,286 won. Hwacheon business model showed that gross income was 31,850,000 won, the operating cost was 13,143,000 won. Thus, the net income was 18,707,000 won. And, break-even point of sale volume, which meets cost, was 617 chicken in Chungju, 125 chicken in Gyeongsan, and 63 chicken in Hwacheon. In terms of selling cost-per-production ratio, Chungju business model was 79%, Kyungsan was 55% and Hwacheon was 41%. The results of this study indicates that margin ratio per chicken was 21% in Chungju, 45% in Kyungsan and 59% in Hwacheon. On Agroforestry, increasing rate for gross income was evaluated by 16% in Chungju, 18% in Gyeongsan and 11% Hwacheon.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.502-508
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• 2007

This paper proposes a method to shut out all of the not certified network access packet by embodying the two-factor(MAC ADDRESS, ID/PASSWORD) authentication system. The Authenticating Gateway System takes over central server's policy and permit or hold up the packet by inherited policy. And checks the whether or not patched the OS version and getting influenced from computer virus. And takes the information about client's resources(H/W, S/W) without Agent in the client. That makes more stability of network operating circumstance and fast facing the attack from hackers. In the fixed mobile network circumstance, This method provides more simplicity and less expenses than IEEE802.1x authentication system(cisco nac).

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.297-304
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• 2020

This paper applies the Data Envelopment Analysis (DEA) to compute the managerial efficiency of 30 insurance companies listed on the Saudi stock exchange for the duration of four years from 2015 to 2018. The companies taken as a sample of study included both conventional and Takaful insurance companies. The insurance sector of KSA is one of the largest sectors in the country, contributing a substantial percentage in the non-oil economy. Efficiency measurement and evaluation will provide a venue to introspect and benchmark frontiers to the sector. In the present study, we have utilized the basic Banker Charnes Cooper and Charnes Copper Rhodes models of DEA. Two inputs, namely, general & administrative expenses and policy & acquisition costs, and two outputs (Net premium earned and Investment Income & other incomes) were taken for efficiency calculations. The final outcomes of the study reveal that a good number of insurance companies operating in KSA are found to be efficient on managerial efficiency scale. Three firms remain the leader on the frontier of the managerial efficiency. And no company found with zero (0) efficiency or a negative efficiency. It is expected that the outcome of the study will provide benchmarks to managers and a road map to further improvement.

• Journal of Distribution Science
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• v.17 no.10
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• pp.41-48
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• 2019

Purpose - This study investigates whether financial analysts consider the intangible investment implicit in selling, general, and administrative (SG&A) expenditures to forecast firms' future earnings. Research design, data, and methodology - Using 52,609 U.S. firm-year observations spanning 1984-2016, this study examines the association between the Intangible investment implicit in SG&A expenditures and properties of analysts' earnings forecasts. To estimate the Intangible investment of SG&A, I decompose SG&A excluding R&D and advertising expenditures into maintenance and investment components following Enache and Srivastava (2017). Results - The main results show that analysts' earnings forecast errors and dispersion in analysts' forecasts increase with the intangible investment derived from SG&A because the investment component of SG&A affects future earnings and the uncertainty of those earnings. However, these results are weakened in the wholesale and retail industries where firms have a higher level of investment component of SG&A. I attribute the weaker results to low R&D expenditures in those industries. Conclusion - This study indicates that financial analysts incorporate the intangible investment of SG&A into their earnings forecasts differently across firms and industries. Furthermore, this study supports the argument for the separate reporting of the investment nature of SG&A from other operating expenses such as maintenance nature of SG&A.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.42-48
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• 2013

The global warming of the Korean Peninsula proceeds most rapidly in the world and its abnormal climate is more deepening. In the result of the surged electricity consumption by intense heat of summer and severe cold of winter, electricity supply and demand status is in hard situation. Currently, the supply of natural gas is increased because natural gas has the lowest greenhouse-gas emissions among the existed fossil fuel. Natural gas cooling has a lot of advantage such as decreasing electricity peak, reducing construction expenses in additional power plant, operating natural gas storage facilities efficiently, and playing a role as distributed generations. Therefore, this study analyzes the economic feasibilities of gas cooling as an alternative for electric power load management.

• IE interfaces
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• v.17 no.1
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• pp.71-77
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• 2004

At the present time, container transportation plays a key role in the international logistics and the efforts to increase the productivity of container logistics become essential for Korean trucking companies to survive in the domestic as well as global competition. This study suggests an approach for determining fleet size for container road transportation with dynamic demand. Usually the vehicles operated by the transportation trucking companies in Korea can be classified into three types depending on the ways how their expenses occur; company-owned truck, mandated truck which is owned by outsider who entrust the company with its operation, and rented vehicle (outsourcing). Annually the trucking companies should decide how many company-owned and mandated trucks will be operated considering vehicle types and the transportation demands. With the forecasted monthly data for the volume of containers to be transported a year, a heuristic algorithm using tabu search is developed to determine the number of company-owned trucks, mandated trucks, and rented trucks in order to minimize the expected annual operating cost. The idea of the algorithm is based on both the aggregate production planning (APP) and the pickup-and-delivery problem (PDP). Finally the algorithm is tested for the problem how the trucking company determines the fleet size for transporting containers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6090-6097
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• 2013

A pneumatically-driven driving simulator that provides a realistic representation of the driving environment was developed. The motion platform for the driving simulator is a mechatronic device that gives a driver the realistic feeling of an actual vehicle. The cost of the motion platform comprises the largest part of the expenses in developing a driving simulator. In this project, to develop a low-cost motion platform, the self-built motion platform based on the Stewart platform configuration that is constructed by six pneumatic cylinders was used as its actuator. The Stewart platform that moves in response to the operating signals of the joystick showed satisfactory tracking performance. We confirmed the possibility of the driving simulator using rFactor that is a commercially available racing game software.

• Journal of Applied Reliability
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• v.16 no.3
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• pp.238-244
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• 2016

Purpose: Domestic electric railway Regenerative Energy Storage System seriously affects the maintenance cost of the total operating expenses of nearly 60% of the total LCC (Life Cycle Cost) due to high dependence on foreign Leading company. Therefore by developing the system, it is important to lower the maintenance cost in the domestic supply. This study about the capacitor Reliability test and the purpose of this study is development electric railway Regenerative Energy Storage System. Methods: In case of, having a close relation between the temperature and the reaction rate, Accelerated Model was known that according to Arrhenius' law of chemical activity. If you apply this formula in using allowable temperature range of the capacitor can induce the Arrhenius empirical formula used in much Manufacture Fields. We evaluate the capacitors Leading company through the Arrhenius model. in order to providing a base for the localization of Ultra Capacitor. Conclusion: In this paper, we conducted a reliability test. And it was performed by the accelerated life test and Cycle Test with temperature and C-rate. and then MTBF and B10 life are estimated by analyzing the accelerated life test result. This is thought to need detailed study applying complex stress than about whether it matches the actual behavior in electric railway.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.1-22
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• 2016

While many organizations believe that cloud computing has the potential to reduce operational cost by abstracting capital assets like data storage center and processing systems into a readily on demand available and affordable operating expenses, still many of these organizations are not aware of the factors determining the performance of cloud computing technology. This paper provides a systematic literature review focusing on the factors determining the performance of cloud computing. In trying to come up with this review, the following sources were searched for relevant articles: ScienceDirect, Scientific.Net, ACMDigital Library, IEEE Xplore, Springer, World Scientific Journal, Wiley Online Library, Academic Search Premier (via EBSCOHost) and EdITLib (Education & Information Technology Digital Library). In first search strategy, approximately 100 keywords related to the research domain like; "Cloud Computing" and "Cloud Services" were used. In second search strategy, 65 keywords more related to the research domain were selected. In the third search strategy, the primary materials were identified and classified according to the paper types (Journal or Conference), year of publication and so on. Based on this study, twenty (20) factors were found that determine the performance of cloud computing. The IT organization needs to consider these twenty (20) factors in order to adopt cloud computing.