• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1710-1715
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• 2010

Service life of water pipes buried in the underground is considerably affected from various factors such as environmental characteristics, pipe characteristics, operation and maintenance, etc. Therefore it is difficult to determine their service life as uniformly the same value assigned by related laws and ordinances. As a result, the service life should be determined by the technical judgement based on the assessment for the condition of water pipes. In this study, It was established that the methodology could predict present and future failure risk, and plan short and long-term strategies for replacement/rehabilitation through the assessment for the physical deterioration and economical values of buried water pipe. The methodology was applied for the verification and reliability to several sites selected in multi-regional transmission pipelines. The proposed method could helps to support reasonable and economical decision of rehabilitation/replacement in the present and future. To improve conventional assessment method of aged water pipes, affecting factors are simplified based on the statistical analysis results from the measured data in the field and the physical deterioration mechanism for better reliability. Also, the guide-line is developed to carry out the reasonal rehabilitation planning through water pipe condition assessment.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.439-443
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• 2001

A lot of buildings, especially apartment housing, have been dismantled so as to enhance the value of the building without exact assesment for the service life and deterioration degree of the building. Remodeling for an aged building is becoming a hot issue to owners in the public sector and the private sector. Peoples including owner, tenants, constructors recognize the fact that the efficient maintenance of the building during the service life and lengthening the practical service life are very important in point of minimizing LCC. This study suggest a decision making system to judge whether to remodel(renovate) or to reconstruct an aged building. The system is composed of structural performance assesment elapsed(or practical service) life evaluation against whole service life, deterioration assesment of the building equipment, dweller's satisfaction, etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.411-414
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• 2002

The depreciation cost in the telecommunication industry plays an important role not olny in calculating a corporation tax and telecommunication charge but also ill evaluating the profitability and national welfare. This paper proposes the study on LRIC model based network costing in major foreign countries and the depreciation methods applicable to telecommunication network. The simulation result from each methods could be based on determining a network costing model and legislation in the telecommunication.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.41-52
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• 2015

The number of military facilities has been rapidly increased due to growing requirement of modernization and military welfare. However, adequate maintenance has not implemented to these facilities. As a result, they are deteriorated quickly and require performance enhancement treatments. There are two ways of performance enhancement, reconstruction and remodeling. Despite the research result that remodeling within the standard remodeling range is more economical, remodeling of military facilities is not considered equivalent to reconstruction as an option of performance improvement. Therefore, derived from the relationship between performance change during life cycle of building and range of remodeling needs, this study tries to propose Remodeling Process Model(RPM) which uses a method to choose remodeling in a Specific Point of Time(SPT) when remodeling is considered more economical than reconstruction. In addition, this study suggests practical service life and functionality evaluation standard together which require to realize the RPM. This RPM make it possible to avoid the cases that facilities which do not have any problem on structural reliability but have low level of functionality miss appropriate remodeling timing and inevitably choose reconstruction as a performance improvement option. It also present the possibility of simple reconstruction / remodeling decision-making for facility managers who administrate building having various type, compilation and elapsed time. Consequently, this process model focusing on remodeling more may contribute to reduce resource waste caused by reconstruction.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.235-236
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• 2017

소수력발전소가 건설 후 점검 및 유지보수를 지속적으로 수행 설비성능을 유지하지만, 30년이 경과하면 노후화 및 피로현상으로 성능이 저하되고 경제적 내용연수가 도래한다. 대수력의 경우 전문인력과 점검 및 보수비용을 투자하여 일상, 주간, 월간, 년간, 정기보수를 수행하고 그 기록을 유지관리하고 있지만, 소수력발전소의 경우는 그러하지 못하여 발전소 효율뿐만 아니라 운용중의 안전도 위협받고 있는 상황이다. 본 논문에서는 국내 시설물 안전관리에 관한 특별법에 의거 필리핀에 위치한 노후 수력발전소의 현대화를 위하여 최초 기존 시설물에 대한 안전진단을 실시하여 토목 및 건축물의 보강을 위한 방법을 선정하고 이를 바탕으로 수력발전설비로부터 발생하는 진동과 같은 다양한 영향을 감소시키기 위한 토목기술을 반영하여 현지 환경에 적합한 수차선정과 노후 시설물의 유지보수를 국내 토목 보수 보강 기술로 설계하였다.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.225-234
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• 2016

This study aimed at analyzing the economic value of 'Fuyu' sweet persimmon. For the analysis, the raw data of the latest 9 years were collected from 707 farmers in major sweet persimmon area and from 47 farmers surveyed in the field. These data include receipt price per kilogram, costs, yields per tree, etc. The findings are as follows: The break-even tree age of sweet persimmon was 85 years. The trees reach the maximum harvest at age of 65. 'Fuyu' sweet persimmon's economic value was 10,488 thousand won in income approach, 9,249 thousand won in cost approach, respectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.4
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• pp.164-169
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• 2007

The estimation of mortality characteristics of industrial property is an important adjunct to engineering valuation and depreciation estimation. Once the important of depreciation estimation is determined, it is desirable to understand the processes upon which these estimates are based. The Iowa type survivor curves are a set of generalized retirement dispersion models. These curves were based on analysis of actual retirement experience and represent typical retirement behavior patterns likely to be encountered. The retirement rate of Iowa type survivor curves on the semiconductor equipments in Korea industry was estimated by the life estimation process. In this paper, estimates of service lives based on directly observed data of the domestic semiconductor equipments are presented.

• Fiber Technology and Industry
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• v.8 no.2
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• pp.192-214
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• 2004

산업의 발달과 인구의 도시 집중, 산업 폐수와 생활하수의 방류로 인한 수질오염은 수자원 환경관리에 심각한 문제로 떠오르고 있다. UN이 분류한 자료에 따르면 우리나라도 10년 이내 절대량의 물 부족이 발생하는 물 부족 예상국가군에 속한다는 보고가 발표되었으며 실제 1995년 당시 약 70%의 예비율로 현재 추세의 물 사용량 증가시 2010년 물부족 사태 발생은 예상이 아닌 현실로 그 대책이 시급하지 않을 수 없다［1］. 그러나 최근 진행된 대책의 내용들은 대부분 지표수에 한정하고 있으며 건설, 토목의 수준으로 강수량에 의존하는 대책에 머물러 문제의 심각성에 대한 논의나 인식이 부족한 상태이다. 즉 건설, 토목 중심의 지표수 저장 기술이 아직은 더욱 경제적일 수 밖에 없지만 지표수와 지하수가 고갈되어 부족현상이 나타나면 결국 수자원의 재활용 및 정수 기술의 적용이 더욱 현실적이고 경제성을 갖게 될 것이다. (중략)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.74-79
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• 2011

Engineering valuation is a specialized discipline requiring expert knowledge and judgment, which scientifically estimates the economic value of industrial properties. By industrial properties, we mean engineering structures such as mines, factories, buildings, machines, and other industrial facilities as well as facilities of public enterprises. Particular industrial properties can have longer economic life if their performance is excellent and they are still suitable for current manufacturing needs. If not, its economic life will be shorter. As speed of technological progress becomes rapid, life-cycle and development period of a product is becoming shorter. In an industry characterized by rapid development of technology, industrial properties can become obsolescent faster. Even if they are in good working order, they could be no longer suitable for manufacturing new products based on radically different technology. In our research, we apply engineering approach to estimating functional economic life by factoring in technological obsolescence in such an industry.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.446-446
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• 2023

우리나라는 물의 재이용 촉진 및 지원에 관한 법률에 따라 수자원의 지속 가능한 이용을 목적으로 빗물이용시설의 설치 및 운영을 법·제도적으로 의무화하고 있으며, 위 법에 근거하여 지방자치단체에서는 빗물이용시설의 설치를 장려하기 위한 재정 지원 정책을 시행하고 있다. 환경 투자사업의 일환인 빗물이용시설 설치 사업은 장기간에 대한 경제성 분석이 요구되며, 분석에 이용된 경제성 분석 방법 및 사회적 할인율에 따라 분석 결과가 상이할 수 있다. 이에 따라, 이 연구에서는 순현재가치와 편익-비용 비율을 비교·검토하여 빗물이용시설의 경제성 분석에 적합한 방법을 제시하였으며, 경제성 분석에서 불확실한 요소인 사회적 할인율과 물가상승률에 대한 민감도 분석을 통해 두 요소의 불확실성을 평가하였다. 분석 대상 시설은 인천 청라지구 1공구에 계획된 빗물이용시설이며, 경제성 분석 기간은 지방공기업법 시행규칙에 제시된 건축물의 내용 연수인 30년으로 하였다. 편익-비용 비율을 이용하여 빗물이용시설의 경제성을 분석한 결과, 저류용량이 285 m³에서 최대 수익률이 나타났으며, 순현재가치는 저류용량이 1105 m³일 때 최대 수익이 발생하는 것으로 분석되었다. 분석 대상 지역의 경우에 285 m³에 대한 양적 신뢰도는 7.3%로 빗물이용시설의 효과를 기대하기 어려운 결과이며, 이와 같은 결과는 편익-비용 비율이 사업의 경제성을 수익률로 평가함에 따라 투자 규모를 반영하지 않는 한계로 인한 것으로 판단된다. 사회적 할인율과물가상승률에 대한 민감도 분석 결과, 사회적 할인율이 낮아지고 물가상승률이 높아짐에 따라 빗물이용시설의 저류용량과 그에 상응하는 최대 순현재가치가 커지는 경향을 보였다. 이는 미래가치를 높게 평가할수록 빗물이용시설의 저류용량이 크게 설계될 수 있음을 의미한다.