• Journal of applied mathematics & informatics
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• 제41권1호
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• pp.95-105
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• 2023

To make the network energy efficient and to protect the network from malignant user's energy efficient grid based secret key sharing scheme is proposed. The cost function is evaluated to select the optimal nodes for carrying out the data transaction process. The network is split into equal number of grids and each grid is placed with certain number of nodes. The node cost function is estimated for all the nodes present in the network. Once the optimal energy proficient nodes are selected then the data transaction process is carried out in a secured way using malicious nodes filtration process. Therefore, the message is transmitted in a secret sharing method to the end user and this process makes the network more efficient. The proposed work is evaluated in network simulated and the performance of the work are analysed in terms of energy, delay, packet delivery ratio, and false detection ratio. From the result, we observed that the work outperforms the other works and achieves better energy and reduced packet rate.

• 간호행정학회지
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• 제16권4호
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• pp.409-418
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• 2010

Purpose: The purpose of this study was to compare the costs and benefits of home nursing care services between public health centers (PHC) and private hospitals. Method: Participants were 105 patients who had received home nursing care services from a private hospital or public health center. From a societal perspective, the researcher identified the costs and benefits of the services using performance data and calculated the net benefit and benefit/cost ratio. Result: The net benefit of the home nursing care service based in the PHC was 165.9 million won and benefit/cost ratio was 2.0, while the net benefit of the home nursing care services by the private hospital was 141.1 million won and benefit/cost ratio was 1.7. Both types of programs were economically validated. Conclusion: Home nursing care services were basically efficient as the results showed a positive net benefit. A cost-benefit analysis indicated that the PHC-based home nursing care services were more efficient than that of the private hospital. With limited human resources and management standards in public health centers, results suggest the need for a more systematic management of the home nursing care service to improve the health of this vulnerable community population.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.437-446
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• 2005

Recently as people's values are changing from development phase into running stage after quality of life, so that the needs of environmentally friendly construction are gradually increasing. Also populace discontent about the pollution during construction process such as the noise and vibration caused by construction machinery is increasing. Even though it is impossible to eliminate the construction pollution fully, it is necessary to make efforts to reduce construction pollution to a minimum. In terms of construction site operating, the first possible step for solving these matters directly is that the necessary sum of expenses must be secured as the environmental management costs in the conceptual phase. However, in fact, the environmental management costs have not been secured in the budget. Generally it is the major reason not arising proper activities to prevent the pollution in the construction site. The purpose of this research is to suggest the efficient budgeting method regarding Environmental management costs to ensure the necessary sum of environmental management expenses. To provide an efficient budgeting method, interviews with the person in charge of environment management was conducted. 78 construction sites was surveyed and environmental management costs were analyzed through their historical data from the survey. According to the results of analysis, the ratio of environmental management costs is revealed 0.45% of construction cost as average comparing 0.2% of legal limit. And usually the environmental management cost was appropriated into the safety management budget. So it is needed to isolate environmental management budget securely and modify the ratio of Environmental conservation Costs in Construction Technology Management Act.

• 대한영양사협회학술지
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• 제6권1호
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• pp.33-43
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• 2000

Environmental pressures from such sources an economic condition, the government and inter-institutional competition create managerial challenges. Economic pressures may be forcing dietetic dept, in hospital to utilize cost∙benefit analysis to assist them in their problem solving. Cost∙benefit analysis have been widely used in business, industry and many other fields with only limited application to foodservice. Due to the lack or this information the purposes of this study were to identify use of cost∙benefit analysis in hospital foodservice system to evaluate the economic efficiency of alternatives, and to make recommendation for operation system change. Using the cost∙benefit method, cash flows are separated into cost and benefits. For an alternative to be selected, indicators, such as NPV, benefit-cost ratio (B/C ratio) with 5% discount rate per annum. The sensitivity analysis was also conducted with difference rate 3%, 7% respectively and reduced employee payroll change. The result of this study can be summarized as follows : 1. The total cost of investment for operation system change was 390,570 thousand won and the total benefit through operation system change was 865,808 thousand won. 2. Net present value(NPV) for 5 years was 475,239 thousand won and benefit-cost ratio was 2.22. 3. In sensitivity analysis with different discount rate 3%, 7%, benefit-cost ratio was 2.25, 2.18 respectively, with total reduced employee payroll change, benefit-cost ratio was 2.86. In conclusion, total benefits were exceeded total costs. Therefore, the project of operation system change in hospital foodservice was found to be economically efficient.

• 한국안전학회지
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• 제16권3호
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• pp.111-116
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• 2001

This study is conducted to review the ratio of direct and indirect cost accompanied by industrial accident in construction sites. It is surveyed that how to use safety cost in construction work is most efficient in comparison with several items of safety cost through the regression analysis.

• 대한교통학회지
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• 제24권3호
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• pp.143-153
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• 2006

본 연구는 국내 외 항공운송산업의 환경 변화에 따라 우리나라 항공운송산업의 비용효율성을 극대화할 수 있는 전략을 제시하고, 나아가 이를 유도할 수 있는 정책방안을 제시하고자 27개 세계 주요 항공사들의 비용 및 산출 자료를 이용해 밀도, 규모 및 범위의 경제성을 추정하였다. 추정결과 KAL과 AAR 모두 국제선의 운항밀도를 증대시키는 것이 비용절감의 효과를 높일 수 있다는 것으로 나타났으며, 운항네트워크와 관련하여 KAL과 AAR 모두 가능하다면 네트워크를 확대하는 것이 적절하지만, 보다 더 비용효율적인 효과를 얻기 위해서는 네트워크 확장보다는 국제선의 운항밀도를 증대시키는 것이 보다 적절한 것으로 나타났다. 다음으로 현재와 같은 국내선 및 국제선 여객 화물의 운항비율을 나타내는 국적항공사의 평균비용을 극소화하는 적정 산출량 수준은 현재 보다 높지만 현재 산출량과 적정 산출량 수준에서의 평균비용간에 큰 차이를 보이지는 않는 것으로 나타났으며, 국내선만 운영하는 항공사의 경우는 국적항공사의 적정 규모보다 훨씬 작은 것으로 도출되었다. 마지막으로 양 국적항공사는 국내선의 운항 비중을 줄여 화물 운항 비중을 현재보다 늘릴 경우 범위의 경제가 크게 발생하는 것으로 나타났다.

• 상하수도학회지
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• 제31권1호
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• pp.51-62
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• 2017

For the asset management of a water pipe network, it would be necessary to understand the extent of the maintenance cost required for the water pipe network for the future. This study would develop a method to draw the optimum cost required for the maintenance of the water pipe network in waterworks facilities to maintain the aim revenue water ratio and to achieve the target revenue water ratio, considering the water service providers' waterworks condition and revenue water ratio comprehensively. This study conducted a survey with 96 water service providers as of the early 2015 and developed models to estimate the optimum maintenance cost of the water pipe network, considering the characteristics of the water service providers. Since the correlation coefficient of all the developed models was higher than 0.95, it turned out that it had significant reliability, which was statistically significant. As a result of applying the developed models to the actual water service providers, it was drawn that increasing revenue water ratio to more than a certain level can reduce the maintenance cost of the water pipe network by a great deal. In other words, it is judged that it would be the most efficient to secure the reliability of waterworks management by increasing the short-term revenue water ratio to more than a certain level and gradually increase the revenue water ratio from the long-term perspective. It is expected that the proposed methodology proposed in this study and the results of the study will be used as a basic research for planning the maintenance of water pipe network or establishing a plan for waterworks facilities asset management.

• 한국병원경영학회지
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• 제11권3호
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• pp.73-93
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• 2006

This study aims at providing necessary informations for management decision-making to the hospital manager, such as ratios of fixed and variable cost to total operating expense, and variable cost ratio to operating revenues, and determinant factors affecting cost behavior. A study model and related hypotheses were established, data were collected from 41 private university hospitals for the 6years from 1998 to 2003, and regression analyses were performed to test the hypotheses. The results of the analyses and conclusions are as follows; First, labor cost and administration cost within the same number of beds have not only fixed quality of the cost, but variable quality of that. Also, the ratio of the variable costs to operating revenue of the metropolitan was estimated 76.9% and that of other area hospitals was 80.1%. Second, the major factors affecting the increase rate of the operating expense were the increase rates of the number of inpatients, the number of employee, and the number of hospital operating bed. This result implies that maintaining a optimal hospital bed size and efficient operation of the beds are important strategic factors of hospital management.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권12호
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• pp.5928-5947
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• 2019

Multicast Mesh based Mobile Ad-hoc NETworks (MANETs) provide efficient data transmission in energy restraint areas without a fixed infrastructure. In this paper, the authors present an improved version of protocol SLIMMER developed by them earlier, and name it SLIMMER-SN. Most mesh-based protocols suffer from redundancy; however, the proposed protocol controls redundancy through the concept of forwarding nodes. The proposed protocol uses remaining energy of a node to decide its energy efficiency. For measuring stability, a new metric called Stability of Node (SN) has been introduced which depends on transmission range, node density and node velocity. For data transfer, a weighted cost function selects the most energy efficient nodes / most stable nodes or a weighted combination of both. This makes the node selection criteria more dynamic. The protocol works in two steps: (1) calculating SN and (2) using SN value in the weighted cost function for selection of nodes. The study compared the proposed protocol, with other mesh-based protocols PUMA and SLIMMER, based on packet delivery ratio (PDR), throughput, end-to-end delay and average energy consumption under different simulation conditions. Results clearly demonstrate that SLIMMER-SN outperformed both PUMA and SLIMMER.

• 교육시설 논문지
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• 제23권6호
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• pp.27-34
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• 2016

Although the scale and number of university facilities have increased, the maintenance of these facilities has not been efficient as maintenance costs incurred during facility operation periods, as well as management time, have not been sufficiently considered. In this study, the maintenance record data of national universities was compared and analyzed to analyze factors that incur maintenance costs according to the uses and costs of the facilities. According to the results, the number of cases of maintenance and repair work for basic educational facilities was shown to be the largest, accounting for 79%. The number of maintenance and repair work occurred according to work type was examined. According to the results, the highest ratio of maintenance and repair work occurred in the field of construction, specifically, the maintenance costs required for facility supplementation accounted for the highest ratio. Maintenance costs per unit area decreased over time in the newer university facilities, while showing a tendency to increase in older university facilities. However, there were cases where maintenance costs did not show any trends due to factors such as the limited maintenance budgets owing to the characteristics of public service facilities and facilities in the stage of deterioration or destruction after the stage of stabilization. This study is considered to be helpful for efficient university facility maintenance plans and budget calculations.