• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.9-18
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• 2002

A capital investment problem is essentially one of determining whether the anticipated cash Inflows from a proposed project are sufficiently attractive to invest funds in the project. The net present value(NPV) criterion and internal rate of return(IRR) criterion are widely used as means of making investment decisions. A positive NPV means the equivalent worth of the inflows is greater than the equivalent worth of outflows, so, the project makes profit. Business people are familiar with rates of return because they all borrow money to finance ventures, even If the money they borrow is their own. Thus they are apt to use the IRR in preference to the NPV. The IRR can be defined as the discount rate that causes the net present value of a cash flow to equal zero. Why the project are accepted if the project's IRR is greater than the investor's minimum attractive rate of return. Against the NPV, the definition cannot distinctly explain the concept of the IRR as decision criterion. We present a new definition of the IRR as the ratio of profit on the invested capital.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 정보화시공 학술발표회
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• pp.103-122
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• 2001

For prediction of ground movement per the excavation step, observational results of ground movement during the construction was very different with prediction during the analysis of design. step because of the uncertainty of the numerical analysis modelling, the soil parameter, and the condition of a construction field, etc. however accuratly numerical analysis method was applied. Therefore, the management system through the construction field measurement should be achieved for grasping the situation during the excavation. Until present, the measurement system restricted by ‘Absolute Value Management system’only analyzing the stability of present step was executed. So, it was difficult situation to expect the prediction of ground movement for the next excavation step. In this situation, it was developed that ‘The Management system TOMAS-EXCAV’ consisted of ‘Absolute value management system’ analyzing the stability of present step and ‘Prediction management system’ expecting the ground movement of next excavation step and analyzing the stability of next excavation step by‘Back Analysis’. TOMAS-EXCAV could be applied to all uncertainty of earth retaining structures analysis by connecting ‘Forward analysis program’ and ‘Back analysis program’ and optimizing the main design variables using SQP-MMFD optimization method through measurement results. The application of TOMAS-EXCAV was confirmed that verifed the three earth retaing construction field by back analysis.

• 농촌계획
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• 제9권4호
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• pp.19-34
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• 2003

The purpose of this study is to investigate an epistemological recognition of rural society. This study suggests an epistemological reorientation for rural society circumscribing diverse theoretical thoughts as well as empirical evidences. Traditional theoretical perspectives in urban-rural dichotomy envisioned by modernistic idea have regarded rural society as a premodern and underdeveloped society. The perspectives also have regarded city as a symbol of civilization and development. These perspectives thought of the function of rural society as a periphery that can survive as a back-up for urban-oriented prosperity. This study shows that these idea have been concentrated on agricultural expansionism and productivism which do not function in the post-modem societies my longer. The present study argues that these modernistic idea give little understanding of implicit value of rural society. Owing to the functional change of rural society which is quite omnipresent in the 21'st centuries in the world, the present study argues that the value of rural society should work even in the market society that has traditionally been regarded as an working-mechanism in urban society. The present study drives a new insight showing that rural renaissance is an explicit existence instead of a phenomenal one.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.506-516
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• 2005

This paper deals with an investment scheduling problem of maximizing net present value of dividend with reinvestment allowed, where each investment has certain capital requirement and generates deterministic profit. Such deterministic profit is calculated at completion of each investment and then allocated into two parts, including dividend and reinvestment, at each predetermined reinvestment time point. The objective is to make optimal scheduling of investments over a fixed planning horizon which maximizes total sum of the net present values of dividends subject to investment precedence relations and capital limit but with reinvestment allowed. In the analysis, the scheduling problem is transformed to a kind of parallel machine scheduling problem and formulated as an integer programming which is proven to be NP-complete. Thereupon, a depth-first branch-and-bound algorithm is derived. To test the effectiveness and efficiency of the derived algorithm, computational experiments are performed with some numerical instances. The experimental results show that the algorithm solves the problem relatively faster than the commercial software package (CPLEX 8.1), and optimally solves the instances with up to 30 investments within a reasonable time limit.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1471-1479
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• 2015

A major portion of the capital costs in the present day power transmission systems are due to the cost of equipment and construction process. Transmission utilities in the recent years are drawing greater attention towards performing life cycle costing studies for cost management and decision making. However, the data involved in these studies are highly uncertain and the effect of these uncertainties cannot be directly included in the study process, resulting in inaccurate solutions. Interval mathematics provides a method for including these uncertainties throughout the cost analysis and provides final solution range in the form of intervals. In this regard, it is essential and extremely important that significant research has to be carried out in understanding the principles of life cycle costing methodology and its applicability to cost analysis of transmission lines along with uncertainties involved in the cost assessment process. In this paper, economic analysis of power transmission lines using interval mathematics has been studied. Life cycle costing studies are performed using net present value analysis on a range transmission lines used in India and the results are analyzed. A cost break even analysis considering right of way costs was carried out to determine the point of economy indifference.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.14-21
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• 2009

The demand and installation for photovoltaic system(namely, PV) has grown steadily in Korea. However, the PV system has a various economic viability according to the PV system characteristic variables such as inverter efficiency, miscellaneous power conditioning losses, azimuth and slope of PV array, PV tracking mode, and so on. The other variables are the monthly consumed electric energy and economic related factor such as initial cost, government subsidy, maintenance cost, inflation rate, energy cost escalation rate, discount rate, etc. Therefore, this study is to present economic evaluation of PV system with those concerned factors by calculating internal rate of return, year-to-positive cash flow and net present value indices.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.224-227
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• 2008

The present study performs a test of a change in a condenser pressure on two kinds of power plants having different condenser pressure-heat rate correction curve and evaluates the results. According to a result of the test, it is confirmed that a sub-critical drum type steam power plant is optimally operated at the condenser pressure of 38㎜Hga that is designed, even during winters. On the other hand, it can be found that a supercritical once through type steam power plant operated at the condenser pressure that is reduced below a design value, that is, up to 28㎜Hga during winters is advantageous in view of turbine efficiency and is operated without a problem in facility operation such as moisture erosion, turbine vibration, etc. Also, the present study compares and reviews a condenser pressure-heat rate correction curve proposed by a manufacturer and a test value. The present study proposes optimum condenser operation pressure capable of concurrently satisfying the stable operation and efficiency improvement of the power plant facility that is operating, making it possible to support an efficient operation of a power plant.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.921-926
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• 2006

The present study has been conducted economic analysis through actual operation of EHP and GHP which are installed at the same building of an university Cost items, such as initial cost, annual energy cost and maintenance cost of each system are considered to analyze LCC and economical efficiency is compared. The initial cost is considered on the basis of actual costs, and annual energy cost is converted into the cost after measuring electricity and gas consumption a day. LCC applied present value method is used to assess economical efficiency of both them. Variables used to LCC analysis are electricity cost escalation rate, natural gas cost escalation rate, interest rate, and service lives and when each of them are 4%, 2%, 8%, and 20 years, results of analysis short that EHP(148,257,306 won) is 8.05%(12,981,990 won) more profitable than GHP(161,239,295 won).

• 한국조리학회지
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• 제7권3호
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• pp.193-209
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• 2001

The result of this study suggests that students' perception of service value is related to functional value with regard to need and satisfaction, epistemic value, image, emotional value, functional value with regard to price and quality, and social value. Specifically female students give less importance to epistemic value than their male counterparts. Students in the 2nd grade gave less favorable scores to the functional value with regard to need and satisfaction, epistemic value, image, emotional value and functional value with regard to price and quality than students in the 1st grade. Students in the night class gave less scores to epistemic value and functional value with regard to price and quality than students in the day class. It is confirmed that the difference between groups by the period in school is in functional value with regard to need and satisfaction, image, emotional value, and functional value with regard to price and quality. And it is also revealed that these results are similar to the results of analysis by the grade. In conclusion college operators should not overemphasize that the department of Hotel culinary arts occupies the leading position of the culinary academic world in Korea and the firms of food service industry positively evaluate the department of Hotel culinary arts, and in order to cope with the rapidly changing environment of the culinary education consistent investment constant changes and of efforts should not be stopped. On one hand the teaching staff of the department of Hotel culinary arts should reconsider their original role, and need behavior and practice to fill their deficiency with steady efforts in terms of students' perceived service value. In addition the students of the department of Hotel culinary arts should not be shackled by the past tradition, should not take a pessimistic view of the present situation, should not take an optimistic view of the future, and should always cultivate their ability to provide for the future.

• 대한토목학회논문집
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• 제32권4D호
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• pp.387-396
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• 2012

교량은 사회간접자본에 해당되는 시설물이다. 본 연구에서는 교량 유지관리 대안들에 대한 경제성 평가방법을 제안하고 이를 검증해 보았다. 각 대안들을 동일시점 기준으로 평가하기 위해 기저년도와 평가년도 개념을 도입하여 적용하였으며, 각 비용발생시기에 따라 이자율이나 할인율을 적용하였다. 본 연구에서는 유지관리 대안의 평가대상을 공사비용에 국한하지 않고, 평가기간을 정하여 유지관리 대안으로 인해 발생되는 관리비용 및 잔존가치를 평가하는 방법을 제안하였다. 직접공사비와 연금현재가치계수를 통해 유지관리 비용산정과 평가방법을 제시하였고, 기저년도를 기준으로 하는 잔존가치 산정방법을 제시하였다. 또한, 경제성 평가시스템을 제안하였고 검증을 통해 계산방법과 그 결과를 분석하여 제시하였다. 제안한 시스템은 실무에 적용할 수 있을 것으로 판단된다.