• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.3
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• pp.392-400
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• 2019

This paper provides a fin actuation system of missile based on electromagnetic-spring mechanism to miniaturize the system and lower the cost. Compared with proportional electro-mechanical actuators, the output of Electromagnetic-Spring Actuators(EMSA) has two or three discrete states, but the mechanical configuration of EMSA is simple since it does not need power trains like gears. The simple mechanism of EMSA makes it easy to build small size, low cost, and relatively high torque actuators. However, fast response time is required to improve the dynamic performance and accuracy of missiles since bang-off-bang operation of EMSA affects the flight performance of missile. In this paper the development of EMSA including parameter optimization and mathematical modeling is described. The simulation results using Simulink and experimental test results of prototype EMSAs are presented.

• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.159-165
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• 2020

With respect to the cause of asymmetric cost behavior, there are two streams of the literature. One stream focused on effect of managerial expectation and the other explained using agency system. In this study, we aim to investigate the determinants of asymmetric cost behavior in these streams. We first examine the impact of managerial overconfidence and optimistic bias on asymmetric cost. We also examine ownership ratio as a proxy of the quality of corporate governance effects on asymmetric cost. The results are as follows. First, firms have the anti-sticky asymmetric cost behavior. Second, we find that the firms with managerial optimistic bias mitigate the degree of asymmetric cost. This finding implies that managerial optimism is a factor that alters asymmetric cost behavior. Third, the degree of asymmetric cost is weaker in case of firms with higher manager's ownership. This result provides an important empirical evidence for understanding the role of corporate governance in cost behavior.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.6
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• pp.19-32
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• 1999

The purpose of this study was to develop of home nursing care classification and home health care costs of the free-standing home nursing care agency. This study was done through 3 steps The First stage, home nursing care classification was identified and classified by literature, review-committee and expert meeting. The second stage, cost elements for home nursing care visit were identified and accounted. That were divided into direct nursing care cost, indirect nursing care cost, management cost and transportation cost. Third stage, total cost of per visit was produced. Data were collected from 810 visits of 120 patients received home dare and from January. 1999 to November, 1999, and analysed with EXCEL program. The obtained results are as follows : 1. Home nursing care classification was consisted of 6 high level classification domain and 10 low level classification domain and 163 home nursing care behavior. 2. The cost of home nursing care per visit was 30,638 won which were direct and indirect nursing care cost(16.305won), management cost(5,255won) and transportation cost (9,098won). In conclusion. Home nursing behavior care classification developed in this study would be used as home health care standard. And the home nursing care costs can be used as a fundamental data for the further development of home health care costs in Korea.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.74-79
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• 2007

고객이 요구한 제품은 테스트에 따라 그의 품질을 보장할 수 있기 때문에 테스트에 대한 관심과 중요성이 커지고 있는 만큼 테스트에 소요되는 비용 또한 실제 개발에 소요되는 비용에서 큰 비중을 차지하고 있고 그 중요성 또한 강조되고 있다. 하지만 실제 국내의 소프트웨어 개발 현실을 살펴 보면 제품의 개발 기한을 보장하기 위해서 테스트를 간과 함으로써 예상치 못하게 고객이 요구하는 제품의 품질을 만족시키지 못하고 있다. 또한 이러한 테스트 활동을 통한 품질 보장 활동의 필요성을 인정하지만 현재 개발 프로세스의 문제점 파악 혹은 개선 방향에 대해서 모호한 비전을 가지고 활동하기 때문에 성과가 미비하기도 하다. 본 논문에서는 국방 소프트웨어의 소프트웨어 개발 활동 내에서의 테스트 활동 및 제품의 품질에 대한 문제점을 지적하고 Cost of Quality (CoQ) 모델을 통해서 문제점을 분석함으로써 고 품질의 제품을 개발하기 위한 테스트 프로세스 개선에 대한 동기 부여 및 개선 방안을 제시하고자 한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.365-370
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• 1995

In recent years, there have been attempts to explain firms' capital structure based upon the agency theory which considers agency problems arising due to ownership structure. Agency theory starts from the coctractual relationship (explicit or implicit) between principals and agents. Since uncertainty exists in real world and information is distributed asymmetrically, there are conflicts between principals and agents. The objectives of this study are to analyze, based upon agency theory, factors which are expected to affect firms' capital structure and to test empirically the relevance of agency cost hypothesis about the determination of capital structure, For these purposes, this paper carried out multiple regression in order to examine whether the factors of agency costs affect significantly the determination of capital structure. The results of empirical analysis are summarrized as follows; First, insider-equity ration has been negatively correlated with capital structure. Second, growth opportunity variabless has been insignificant coefficients with capital structure.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.271-276
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• 2021

In this paper we analyze the effect of the credit period on inventory policy under trade credit with ordering cost including a fixed cost and freight cost, where the freight cost has a quantity discount. For marketing purposes, some supplier offers credit period to his buyer to stimulate the demand for the product he produces. The delay in payments during the credit period has the effect of reducing the buyer's capital opportunity cost. It is also assumed that the buyer pays the freight cost for the order and hence, the ordering cost consists of a fixed ordering cost and a variable freight cost which depends on the order quantity. As a result, the possibilities of trade credit and discounts on freight costs are expected to play an important role in the buyer's inventory policy. Based on the economic order quantity inventory model, we analyze how the buyer can determine the optimal inventory policy and we examine the effect of the length of credit period on the buyer's inventory policy.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.665-674
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• 2018

In this paper, we propose a development results of a D-type non-rechargeable lithium battery($Li/SOCl_2$) on improvement in a low cost protection circuit of discharge for domestic military power source. According to this study, we describe a new design and product with 8-bit microcontroller in the protection circuit which can estimate state of health of the battery regardless of occurring an initial voltage delay. Also this paper discuss and facilitate development as solution to a safety about the non-rechargeable lithium batteries. As a result, we verified a quality of the protection circuit by a development test and evaluation(DT&E) process.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.34-41
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• 2015

Bonding strength of a thermal sprayed coating is difficult to measure using a conventional pull-off test method. Scratch test is a potential alternative testing method. An adhesive and a cohesive bond strength of the coating can be measured by the pull-off test while the scratch test performed on the cross-section of the thermal sprayed coating can only demonstrate the cohesive bond strength of the coating. Nevertheless, it is still beneficial to perform the scratch testing on the cross-section of the coating for the sake of comparison thus providing an alternative to the pull-off test. The scratch test method can reduce testing time and cost in the long run due to a significant cost reduction in consumables and energy and time saving from the curing step of the glue used in the pull-off test. This research investigates the possibility of using the scratch test to measure the cohesive bond strength of Mo/NiCrBSi composite coating. The results from the pull-off test and the scratch test indicate that the cohesive bond strengths of the Mo composite coating show similar trend and that the cohesive bond strength are increased when increasing NiCrBSi content.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2317-2322
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• 2015

Background: Despite the increasing number of screening examinations performed for cervical cancer utilizing the Papanicolaou smear test (Pap test), few studies have examined whether this strategy is cost-effective in Korea. Objective: This study was conducted to evaluate the cost-effectiveness of cervical cancer screening strategies incorporating the Pap test based on age at the start and end of screening as well as screening interval. Materials and Methods: We designed four alternative screening strategies based on patient age when screening was started (20 or 30 years) and discontinued (lifetime, 79 years). Each strategy was assessed at screening intervals of 1, 2, 3, or 5 years. A Markov model was developed to determine the cost-effectiveness of the 16 possible cervical cancer screening strategies, and this was evaluated from a societal perspective. The main outcome measures were average lifetime cost, incremental quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER). Results: Compared with various strategies comprising younger starting age, discontinuation age, and longer screening intervals, strategies employing annual screening for cervical cancer starting at a target age of 30 years and above were the most cost-effective, with an ICER of 21,012.98 dollars per QALY gained (with a Korean threshold of 30,000,000 KRW or US$27,272). Conclusions: We found that annual screening for cervical cancer beginning at a target age of 30 years and above is most cost-effective screening strategy. Considering the potential economic advantages, more intense screening policies for cervical cancer might be favorable among countries with high rates of cervical cancer and relatively low screening costs.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1158-1164
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• 2007

Recently, the demand on the practical application of life-cycle cost effectiveness for design and rehabilitation of civil infrastructure is rapidly growing unprecedentedly in civil engineering practice. Accordingly, it is expected that the life-cycle cost in the 21st century will become a new paradigm for all engineering decision problems in practice. However, in spite of impressive progress in the researches on the LCC, so far, most researches in Koreahave only focused on roadway bridges, which are not applicable to railway bridges. Thus, this paper presents the formulation models and methods for uncertainty-based LCCA for railroad bridges consideringboth objective statistical data available in the agency database of railroad bridges management and subjective data obtained form interviews with experts of the railway agency, which are used to anew uncertainty-based expected maintenance/repair costs including lifetime indirect costs. For reliable assessment of the life-cycle maintenance/repair costs, statistical analysis considering maintenance history data and survey data including the subjective judgments of railway experts on maintenance/management of railroad bridges, are performed to categorize critical maintenance items and associated expected costs and uncertainty-based deterioration models are developed. Finally, the formulation for simulation-based LCC analysis of railway bridges with uncertainty-based deterioration models are applied to the design-decision problem, which is to select an optimal bridge type having minimum Life-Cycle cost among various railway bridges types such as steel plate girder bridge, and prestressed concrete girder bridge in the basic design phase.