• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권4호
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• pp.923-948
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• 2013

The main concern in mobile peer-to-peer (P2P) networks is security because jamming or eavesdropping on a wireless link is much easier than on a wired one and such damage can be incurred without physical access or contact. In particular, authentication has increasingly become a requirement in mobile P2P environments. This paper presents a new mutual authentication mechanism which requires less storage space and maintains a high level of security in mobile P2P networks. The proposed mechanism improves efficiency by avoiding the use of centralized entities and is designed to be agile in terms of both reliability and low-cost implementation. The mechanism suggested in the simulation evaluates the function costs occurring in authentication between the devices under mobile P2P network environment comparing to existing method in terms of basic operation costs, traffic costs, communications costs, storage costs and scalability. The simulation results show that the proposed mechanism provides high authentication with low cryptography processing overhead.

• 한국건축시공학회지
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• 제12권4호
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• pp.401-414
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• 2012

The adoption of Green Frame is expected to provide economic benefits, since construction costs are reduced by the in-situ production of precast concrete column and beam. The cost reduction can ultimately be realized by saving transportation costs and the overhead and profit of PC plants. The cost structure of Green Frame, which is built up using composite precast concrete members, is similar to that of a bearing-wall structure, but the difference in construction process has resulted in some cost differences for a few items. In particular, production and installation is the principal work involved in Green Frame made by precast concrete members, while form and concrete work is the principal work for a bearing-wall structure. As such, the rental time and fee for a tower crane should be compared through time analysis. To verify reliability, this study focused on developed residential projects to estimate the construction costs. Through this analysis, it was found that the costs of Green Frame were 1.57% lower than the costs of bearing-wall structure. The results of this study will help in the development of a management plan for the structural work of Green Frame.

• 한국식품조리과학회지
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• 제23권1호통권97호
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• pp.90-98
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• 2007

The purpose of this study was to apply the activity-based costing (ABC) model to restaurant menu costing. The overhead cast of six entr${\acute{e}}$es in XYZ restaurant was calculated for all levels of activity. When comparing activity-based costing with traditional costing applied to BBQ pork rib and an assorted seafood platter, the total difference of costs between two items was 2,191 won in activity-based costing and 600 won in traditional costing. The average food cast percentage of the six entr${\acute{e}}$es was 27% using traditional costing, while the average activity-based cost percentage was 40%. Therefore, there was a 13% difference between the actual margin volume and the expected margin volume. The application of activity-based costing to the restaurant industry would be a milestone from a cost point of view as well as from a process point of view. In particular, the limitation that traditional costing only accounts for food costs could be overcome b considering the overhead cost as an important part of the cast structure. Furthermore, activity-based costing would not only help to reduce the costs associated with the process of analyzing the activities but it would also provide more accurate cost information for menu pricing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1173-1177
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• 2004

The high investment is necessary for the new high speed lines. So the KRRI was interested in the possibility of upgrading the existing line in order to speed up the train in the conventional lines. The tilting train system has been developed because the reconstruction of railway for the cant compensation costs very high. The purpose of the tilting system is to compensate the centrifugal acceleration in order to reduce the lateral acceleration of the passenger at high speed on the curves.The pantograph of the tilting train is indispensable in order to supply the electrification equipments with power in safe. The dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force and the contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the active control of pantograph and presents the LQ-servo controller to reduce the contact force variation.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권5호
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• pp.582-594
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• 2016

Various test data compression techniques have been developed to reduce the test costs of system-on-a-chips. In this paper, a scan chain reordering algorithm for code-based test data compression techniques is proposed. Scan cells within an acceptable relocation distance are ranked to reduce the number of conflicts in all test patterns and rearranged by a positioning algorithm to minimize the routing overhead. The proposed method is demonstrated on ISCAS '89 benchmark circuits with their physical layout by using a 180 nm CMOS process library. Significant improvements are observed in compression ratio and test power consumption with minor routing overhead.

• 한국병원경영학회지
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• 제8권3호
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• pp.118-142
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• 2003

This study is aimed at evaluating the financial structure of hospitals before and after the separation of prescription and drug dispensing policy started to be implemented in July 2000 and at making a suitable hospital managerial strategy through the verification of the factors which have effect on their profitability. This study investigated the hospitals which have passed the accredition review to be designated as a accredited training hospital each year for three years from 1999 to 2001. Those hospitals were selected from members of the Korea Hospital Association. 106 hospitals were targeted for analysis except for the hospitals whose financial statements and managerial performance were not reported faithfully. The financial indicators used in this study were stability indicators(liability to total assets, ratio of debt to fund balance, fixed ratio), liquidity indicators(current ratio, quick ratio), activity indicators(total assets turnover, fixed assets turnover), profitability indicators(net profit to total assets, net profit to net worth, operating margin), and operating expenses to patient revenues indicators(drug and supplies costs/payroll/overhead expenses). The result of this study are as follows: First, the analysis of the increase of loss-making hospitals before and after. The separation of prescription and drug dispensing policy shows that the number of loss-making hospitals increase after the separation(22.6% before the separation; 31.1% after the separation). However, there was no significant statistical difference. Second, the analysis of operating expenses to patient revenues indicators showed that the ratio of drug and supplies cost became lower in all hospitals but the ratio of payroll/overhead expenses became higher. Additionally, the factor which have the greatest effect on profitability was operating expenses to patient revenues indicators (drug and supplies costs/payroll/overhead expenses). Third, the analysis of managerial performance by four types of loss-loss, loss-profit, profit-loss and profit-profit compared the results before the separation with those after the separation revealed as follows : Reliance on liability to total assets became higher in the profit-loss type($56.2%{\rightarrow}66.4%$), lower in the loss-profit type($82.7%{\rightarrow}74.5%$). Total assets turnover became higher in the profit-profit type($1.3{\rightarrow}1.5$), but lower in the loss-profit type($0.8{\rightarrow}0.7$). Operating margin decreased to minus 5.9% from 4.3% in the profit-loss type, but increased to 7.2% from minus 7.8% in the loss-profit type. Forth, operating expenses to revenues indicators showed that the increase of payroll was the biggest in the profit-loss type($39.2%{\rightarrow}49.9%$) and that overhead cost decreased in the loss-profit type but that rather increased in other types.

• 전기학회논문지
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• 제64권2호
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• pp.349-352
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• 2015

This paper estimates electrical fire damage cost-effect to analyze electrical safety efficiency by applying a cost-benefit analysis method for analyzing the efficiency of a business public interest. Electrical fire loss statistics data was presented as direct costs and casualties, including deaths due to an electrical fire, this paper adds overhead "Incidental Cost of Accidents to the Employer" by W. H. Heinrich was applied to estimate the cost of economic loss. Also wounded, including the loss of human deaths by referring to the car accident insurance claims costs and human development estimated the losses caused by an electrical fire. And to perform a cost-benefit analysis of the electrical safety as a result of future work. In this paper, the economic effect of the electric field of safety and public interest work to systematically presented.

• 한국국방경영분석학회지
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• 제31권2호
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• pp.1-12
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• 2005

Defense firms' excess profitability by shifting common overhead costs from non-defense sector to defense sector in the award of cost reimbursement type of defense contracts is a widespread conclusion in prior researches. In this paper, we reviewed cost-shifting incentives in defense-contracting firms and extended the analysis of McGowan and Vendrzyk(2002) by applying modified model to Korea Defense Contracts. We formulated six hypotheses to test the relation of cost-shifting and excess profitability regarding market openness, auditing system, ranking in defense contracts, and firm types(sole defense contractors, sole non-defense contractors, and defense and non-defense mixed contractors). But, we could not find any evidence that defense firms shifted costs from non-defense sector to defense sector for the period 1997-2002. The results suggest that the excess profitability of Korea defense firms may not be from the cost-shifting but from other reasons.

• 한국조리학회지
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• 제3권
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• pp.165-179
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• 1997

Cost-volume-profit analysis shows the relationship between these factors. The figures expressed in a break-even chart can be used planning control and decision making. The relation ships can also be helpful in understanding how all costs must be covered in menu pricing. Involved in these relationship is the contribution to overhead and profit, or contribution ratio. This study used the food service operation of H hotel. Assumed the FC would be 10% of the High Volume, the VC would be 76% of the high volume. And in the CVP of individual meals, selected labor cost of the VC, assumed labor cost would be 35% of the volume.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (A)
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• pp.10-12
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• 2002

사용자의 요구와 인터넷 어플리케이션의 발달로 규모가 큰 미디어 오브젝트의 수가 급증하고 있다. 따라서 네트워크 전송비용은 반드시 고려해야 하는 중요한 요소이다. 본 논문에서는 기존 프락시 캐시 교체 정책들을 분석하고, 이를 개선한 G-N 및 L-N 정책을 제안한다. 이것은 프락시 캐시 소프트웨어인 'Squid'에서 채택하고있는 GDSF와 LFU-DA 정책에 네트워크 전송 비용을 추가하여 확장한 알고리즘이다. 시뮬레이션을 통하여 기존의 알고리즘과 비교해 본 결과, 평균 응답 시간을 10%이상 감소시킬 수 있었으며, 추가로 드는 비용(Processing Overhead)은 3게 증가하지 아니 하였음을 확인하였다.