• Title/Summary/Keyword: Unit cost

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The optimal operation condition of heat engine (熱機關의 最適 運轉條件)

  • 정평석;김수연
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.6
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    • pp.971-974
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    • 1987
  • Considering heat transfer and heat loss processes for the heat engine operating between two fixed heat reservoirs, it may be qualitatively explained that the maxima of power output and its efficiency depending upon operating conditions are extreme maxima. Furthermore, it is also found that from an economic point of view the above two extremes are related to extreme minima of plant cost per unit power output and operation cost per unit power output respectively, and the condition of minimum cost per unit power output exists between the extreme minimum conditions of plant cost per unit power output and that of operation cost per unit power output.

Development of an Unit Cost Modification Model for Proper Actual Cost Data in Small Building Construction Projects (소규모 건축공사의 적정 실적공사비 단가보정 모델 개발)

  • Kim, Kang-Shik;Hyun, Chang-Taek;Hong, Tae-Hoon;Jo, Seong-Min;Mun, Hyun-Seok
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.1
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    • pp.81-89
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    • 2010
  • Since 2004, the government has changedthe cost estimate system to one of an actual cost basis in order to calculate the optimum construction cost by reflecting changes in circumstance on the construction site in a timely manner. Currently, this is being applied to public construction work forover a billion won of actual cost data in estimation by contract unit cost. However, directly reflecting actual cost, which for large-sized construction work was originally an average unit cost, to a small building, entails the application of a low discount rate for the cost of materials, labor, etc. and therefore can frequently give rise to cases in which the actual cost of work performed exceeds the contract sum, which in turn causes problems such as decreased revenues, bad effectson business operation, productivity, etc. Therefore, to apply actual cost to small-sized construction work (less than a billion won), there should be a plan to modify unit cost in a manner that can reflect project scale, etc. in order to resolve the problem of unit cost application of actual cost to small-building construction projects. The unit cost modification model for proper actual construction cost in small-scale construction projects developed by this study will help to increase the relevant productivity and proper gain, preventing the aggravation of business operations. Organizations placing orders are also expected to be able to secure a more realistic construction cost in arranging the budget.

A Study on the Cost Estimate System Development Method for Nuclear Power Plant Construction Projects

  • Lee, Sang Hyun
    • International conference on construction engineering and project management
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    • 2017.10a
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    • pp.133-137
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    • 2017
  • Nuclear power plants in Korea are usually built based on a duplicated model; so the project cost data of the preceding unit can be used as reference when estimating the project cost for the succeeding unit. However, since the contracting method is oriented towards the price, empirical factors such as making top-down estimations using the reverse calculation method based on the completion cost of the preceding unit is dominant. In order to develop a project cost database to resolve such problems, the detailed cost boundary of the project cost data must be categorized by project and by system. This study proposes a method to connect the code of account with the base quantities and the IAEA account, and proposes a database structure for the development of a project cost estimation system. The estimation system developed in the future is expected to utilize the proposed project cost data structure.

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A Cost Analysis Model of Minimal-Repairable Items in Free Replacement under the Periodic Maintenance Policy (정기보전제도에서 응급수리제품에 대한 무상수리 적용의 비용분석 모델)

  • 김재중;김원중;조남호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.19 no.39
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    • pp.89-98
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    • 1996
  • This paper is concerned with cost analysis model in free -replacement policy under the periodic maintenance policy The free-replacement policy with minimal repairable item is considered as follows; in a manufacturer's view point operating unit is periodically replaced, if a failure occurs between minimal repair and periodic maintenance time, unit is remained in a failure condition. Also unit undergoes minimal repair at failures in minimal-repair interval. Then total expected cost per unit time is calculated according to maintenance period Tin a viewpoint of consumer's. The expected costs are included repair cost and usage cost: operating, fixed, minimal repair and loss cost. Numerical example is shown in which failure time of item has beta distribution.

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A Novel Driving Method for Cost Competitive a-Si TFT-LCD

  • Moon, Su-Hwan;Lim, Hong-Youl;Kim, Dae-Kyu;Lee, Min-Kyung;Ko, Kyung-Tai;Lee, Jun-Ho;Yoon, Sung-Hoe;Kim, Byeong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.470-473
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    • 2009
  • We have developed a novel driving method, Six times Rate Driving(SRD) for the purpose of making cost competitive TFT-LCD. By applying SRD method to an a-Si TFT-LCD, the driving rate was increased six times as it was named but the number of data lines and so its D-Ics were reduced to one sixth of the conventional one which resulted in the cost saving of that much. We also newly designed the gate driver in order to avoid any expansion of the bezel width caused by applying SRD. Our newly developed driving technology, SRD was successfully applied to 7.0-inch WSVGA (1024 ${\times}$ 600) TFT-LCD which can be driven with only one data D-IC and here introduced.

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Preventive maintenance policy following the expiration of replacement-repair warranty (교체-수리보증이 종료된 이후의 예방보전정책)

  • Jung, Ki-Mun
    • Journal of Applied Reliability
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    • v.12 no.2
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    • pp.57-66
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    • 2012
  • In this paper, we consider the periodic preventive maintenance model for a repairable system following the expiration of replacement-repair warranty. Under this preventive maintenance model, we derive the expressions for the expected cycle length, the expected total cost and the expected cost rate per unit time. Also, we determine the optimal preventive maintenance period and the optimal preventive maintenance number by minimizing the expected cost rate per unit time. Finally, the optimal periodic preventive maintenance policy is given for Weibull distribution case.

The Characteristics of the Repair Unit Cost in Public Rental Housing (공공임대주택 단위 수선비용 특성 분석)

  • Lee, KangHee;Chae, ChangU
    • KIEAE Journal
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    • v.14 no.5
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    • pp.103-109
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    • 2014
  • Apartment housing should require the systematic maintenance to provide the decent living condition during its life. Each household should participate the maintenance activities and pay for the repair. Therefore, the required cost for repair would be needed to plan in the repair schedule because each household could not pay the much repair money at a time. After apartment constructed, a long term repair plan would be prepared in repair time, repair scope and a required cost. A few studies are said that the repair cost depends on the building deterioration, elapsed year and management factors. The above factors are not be certain to affect the repair management while it may be important to prepare the required money and the repair time. In this paper, it aimed at analyzing the correlation between the repair management and the management factors, especially total area, number of household. This would educe the unit cost per number of household and management area in the individual boiler and elevator with full change and full repair. The unit cost per number of household and area for full change are about 199,000 won/household and $1,954won/m^2$ in the individual boiler respectively. The unit cost of the elevator for full change is 94,000 won/household and $5,429won/m^2$ respectively. Second, this study shows that the elapsed year after construction would not be related the repair unit cost.

Development on Repair and Reinforcement Cost Model for Bridge Life-Cycle Maintenance Cost Analysis (교량 유지관리비용 분석을 위한 대표 보수보강 비용모델 개발)

  • Sun, Jong-Wan;Lee, Dong-Yeol;Park, Kyung-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.128-134
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    • 2016
  • Estimating the repair and reinforcement (R&R) costs for each bridge member is essential for managing the life cycle of a bridge using a bridge management system (BMS). Representative members of a bridge were defined in this study, and detailed and representative R&R methods for each one were drawn in order to develop a systematic maintenance cost model that is applicable to the BMS. The unit cost for each detailed R&R method was established using the standard of estimate and historical cost data, and a systematic procedure is presented using an integration program to enable easy renewal of the R&R unit cost. Also, the average unit cost of the representative R&R methods was calculated in the form of a weighted average by considering the unit cost and application frequency of each detained R&R method. The appropriateness of the drawn average unit cost was reviewed by comparing and verifying it with the previous historical unit cost. The suggested average R&R unit cost can be used to review the validity of the required budget or the appropriateness of the R&R performance cost in the stage to establish the bridge maintenance plan. The results of this study are expected to improve the reliability of maintenance cost information and the rationality of decision making.

Analysis of the Nursing Interventions Performed in the Medical & Surgical Units and the Health Insurance Cost Items Based on the NIC (간호중재분류체계(NIC)에 근거한 내${\cdot}$외과계 간호단위의 간호중재 수행 및 건강보험 수가 항목 분석)

  • Park, Ok-Yeob;Jung, Myun-Sook
    • Journal of Korean Academy of Nursing Administration
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    • v.11 no.4
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    • pp.449-467
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    • 2005
  • Purpose: This study aims to offer the fundamental data in order to cost the nursing service on the basis of the NIC and a close examination of the interventions that are contained in the health insurance cost list under the system of the current health insurance. Methods: The data is handled with the SPSS 10.0 program. The participants' general peculiarity is calculated in terms of the real number and the percentage, and the performing frequency of the nursing interventions is calculated in terms of the mean and the standard deviation. the correlation between the participants' general peculiarity and the performing frequency of the nursing interventions is analysed with t-test or one way ANOVA of SPSS. Results: In the performing frequency of the nursing interventions, the domain of "the physiological: basic" was the highest as 2.69${\pm}$1.21, the domain of "the behavioral" was the lowest as 2.11${\pm}$1.12. There were 50 core interventions in the medical unit, 48 in the surgical unit, 24 in the MICU and 33 in the SICU. The health insurance cost items contained commonly in the core interventions of each unit were 12, and the health insurance cost items except 12 items contained commonly in the core interventions of each unit were appeared 14 items in the medical unit, 6 in the surgical unit, 7 in the MICU and 2 in the SICU. The core interventions contained commonly in four units of the medical unit, the surgical unit, the MICU & the SICU are 18. And among these, the core interventions contained in the health insurance cost items are 10; pain management, hyperglycemia management, analgegic administration, medication administration: intravenous, oxygen therapy, pressure ulcer prevention, fluid management, fluide monitoring, intravenous(IV) insertion, intravenous(IV) therapy. As the result of the comparison & analysis between the core interventions of the NIC and the health insurance cost items, the core interventions contained in the health insurance cost list are 21(29 as the health insurance cost items). Conclusion: In the performing frequency of the nursing interventions, the domain of "the physiological: basic" is being performed most frequently, and in the performing frequency of the core interventions, the interventions of the domain of "the physiological: complex" is being performed most frequently. On the basis of these results, the writer hopes that the attempts to interlink the nursing interventions into the nursing cost by using of standard terms and the efforts to cost the nursing services would also be made in the future constantly.

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An optimal continuous type investment policy for the surplus in a risk model

  • Choi, Seung Kyoung;Lee, Eui Yong
    • Communications for Statistical Applications and Methods
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    • v.25 no.1
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    • pp.91-97
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    • 2018
  • In this paper, we show that there exists an optimal investment policy for the surplus in a risk model, in which the surplus is continuously invested to other business at a constant rate a > 0, whenever the level of the surplus exceeds a given threshold V > 0. We assign, to the risk model, two costs, the penalty per unit time while the level of the surplus being under V > 0 and the opportunity cost per unit time by keeping a unit amount of the surplus. After calculating the long-run average cost per unit time, we show that there exists an optimal investment rate $a^*$>0 which minimizes the long-run average cost per unit time, when the claim amount follows an exponential distribution.