• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.677-684
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• 2008

The paper provides an approximate cost estimating model that can be used for tunnel. Based on the previous study analyzed critical factors that have impact on tunnel construction cost, this paper establishes a cost variance index table that reflects the cost impacts due to the change of the critical cost factors. An estimating procedure is described utilizing the index table. For the verification of the suggested model, the comparison of the estimated construction cost with real project cost is performed. The estimated results range from 95%~111% of the real project costs. As an approximate tunnel cost estimating model, the model can be utilized to quickly estimate tunnel construction costs based on the conceptual information at the planning stage and to efficiently make a decision on design alternatives.

• Knowledge Management Research
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• v.23 no.1
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• pp.89-109
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• 2022

Due to COVID-19 and soaring participation of individual investors, large-scale transactions exceeding system capacity limits have been reported frequently in the capital market. The capital market IT systems, which the impact of system failure is very critical, have encountered unexpectedly tremendous transactions in 2020, resulting in a sharp increase in system failures. Despite the fact that many companies maintained large-scale system capacity planning policies, recent transaction influx suggests that a new approach to capacity planning is required. Therefore, this study developed capital market IT system capacity planning models using machine learning techniques and analyzed those performances. In addition, the performance of the best proposed model was improved by using sentiment index that can promptly reflect the behavior of investors. The model uses empirical data including the COVID-19 period, and has high performance and stability that can be used in practice. In practical significance, this study maximizes the cost-efficiency of a company, but also presents optimal parameters in consideration of the practical constraints involved in changing the system. Additionally, by proving that the sentiment index can be used as a major variable in system capacity planning, it shows that the sentiment index can be actively used for various other forecasting demands.

• Advanced Industrial SCIence
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• v.1 no.2
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• pp.24-29
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• 2022

Recently, smart farm research that applies IoT technology to various farms is being actively conducted to improve agricultural cooling power and minimize cost reduction. In particular, methods for automatically and remotely controlling environmental information data around smart farms through IoT devices are being studied. This paper proposes a processing model that can maintain an optimal growth environment by monitoring environmental information data collected from smart farms in real time based on machine learning. Since the proposed model uses machine learning technology, environmental information is grouped into multiple blockchains to enable continuous data collection through rich big data securing measures. In addition, the proposed model selectively (or binding) the collected environmental information data according to priority using weights and correlation indices. Finally, the proposed model allows us to extend the cost of processing environmental information to n-layer to a minimum so that we can process environmental information in real time.

• Journal of Energy Engineering
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• v.11 no.4
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• pp.317-323
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• 2002

This paper proposed the calculation method of the generation operating avoided cost to cost-effectiveness evaluation of energy conservation programs that compounded the Proxy Plant Method and Load Decrement Method. This method introduced an operating index of the Energy Efficiency Demand-Side Management (EEDSM) resources based on the end-user's behaviors on the electricity power usage. The operation index is applied to calculate the hourly operating capacity of diffused high-efficiency appliances. And the operating capacity on the peak load hours for reference load is computed through the reduction of the peak load that contributes to that hour. Also, the proposed method evaluated the effect of EEDSM resources. The IEEE-RTS is adopted as a sample system to analyze impacts of an EEDSM. This paper, we have analyzed the effect of EEDSM upon the changes in the generation of generator, generation cost and the system marginal price (SMP). This method can be used to evaluate the impact of the diffused DSM resource and to estimate the impact in short-term EEDSM program. Further, result of the calculation can be utilized to pabulum for effect analysis of EEDSM resources.

• Proceedings of the Korea Society for Simulation Conference
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• 1996.05a
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• pp.9-9
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• 1996

광대역 종합정보 통신망의 핵심요소라 할 수 있는 ATM 스위치의 성능척도 중 가장 중요하게 다루어지고 있는 것은 셀 손실확률과 셀 전달지연시간이다. 이 중에서도 샐 손실확률기 추정에 대한 연구가 활발히 진행되고 있는데, ATM 스위치는 손실에 민감한 트래픽까지도 제대로 다루기 위하여 정도까지의 샐 손실확률을 보장할 수 있어야 한다. 이와같은 희소사건(rare event)의 확률 추정에 있어 원하는 정도의 precision을 가능한한 적은비용으로 얻어내기 위한 분산축소기법은 필수적이라 할 수 있다. Homogeneous 입력원을 갖는 ATM 스위치의 셀 손실확률 추정에 관련된 이전의 연구결과는 시뮬레이션과 분석적기법을 혼합시켜 얻어지는 새로운 개념의 추정치, 즉 hybrid 시뮬레이션 추정치의 도입을 통하여 상당한 정도의 분산축소 효과를 거둘 수 있음을 나타내주고 있다. 본 연구는 이에 대한 확장으로, 각각의 도착 프로세스가 서로 다른heterogeneous 입력원을 갖는 ATM 스위치의 셀 손실화률 추정에 적용될 수 있는 hybrid 시뮬레이션 기법을 개발하고자 한다. 사용된 모델은 이산시간대기모델()로 각입력원의 도착 프로세스는 Interrupted Bernoulli Process로 가정하였으며, 분석적 기법의 적용을 위한 입력원 통합(aggregation) 알고리듬과 실제 시뮬레이션 방법 등을 제시하였다. 또한 제시된 기법의 성능은 기존의 일반적인 시뮬레이션 추정치를 이용하여 얻어진 결과와의 비교를 통하여 분석되었다.

• Korean Journal of Construction Engineering and Management
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• v.15 no.5
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• pp.3-12
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• 2014

With the scale of program management getting larger and complexity, More accurate and precise method for management cost estimate is demanded. However, most of project management cost estimates are based on similar cases and hence can not reflect distinct features of each project. Cost estimate precision is also not up to the standards, and also troublesome to policy-making and budget allocation. Therefore, project typical model for cost estimate of Comprehensive Project Management is developed, and makes it easier to manage level of effort and allocate cost by applying characteristic factor of each project. This study categorized the project package by phase; planning, detailed design, and bid procurement, to develop typical model. And by designating specific level of effort required for each field and rank, the study aims to improve the method for calculating the detailed and objective program cost. Outcome of this study will prevent conflicts between client and contractor, accurately calculate program management contract cost for the client, and become a reference for the contractor to receive rational and practical payments for their work.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.26-38
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• 2020

Mixture design of self-compacting concrete is a typical multi-criteria decision making problem and conventional mixture designs are based on the low level engineering method like trials and errors through iteration method to satisfy the various requirements. This study concerns with performing the straightforward multiobjective design optimization of economic SCC mixture considering relative importances of the various requirements and cost-effectives of SCC. Total five requirements of 28day compressive strength, filling ability, segregation stability, material cost and mass were taken into consideration to prepare the objective function to be formulated in form of the weighted-multiobjective mixture design optimization problem. Economic SCC mixture computational design can be given in a rational way which considering material costs and the relative importances of the requiremets and from the result of this study it is expected that the development of SCC mixtue computational design and the consequent univeral concrete material design optimization methodology can be advanced.

• Korean Journal of Construction Engineering and Management
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• v.1 no.3 s.3
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• pp.101-107
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• 2000

On 1 July, 2000, the Ministry of Construction and Transportation announced the Earned Value Management System(EVMS) will be applied in public sector soon. However the arguments over the EVMS applied to our unique construction environment still exist and create strong concerns and worries among some experts it would be another mistakes proposed by the government. We do know the EVMS comes from C/SCSC which was first released by the United States Department of Defense in December 1967, and proved very powerful and efficient project management tool from a lot of practices. Although it is an excellent tool, we can not ignore our many experienced failures appling foreign system due to the differences of construction culture and law between the Korean and US construction industries. The purpose of the EVMS's success in Korea, therefore, this paper tests and proves the EVMS's adaptability and credibility to our construction environment by EAC model, that is one of the most important functions in the EVMS, using very scare EV data of the Korean construction projects.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.469-470
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• 2011

국도는 사회간접자본 중 하나로서 지속적으로 관리되어야 그 기능을 발휘할 수 있는 국가의 중요한 자산이다. 지금까지는 국도를 포장관리시스템이라는 체계로 관리하여왔다. 이 포장관리시스템은 시설물유지관리차원에서 사회기반시설을 관리하는 것으로서 주로 관리자 관점에서 공학적 판단을 기준으로 최소의 비용으로 공용수명을 최대화하는 모델이다. 그러나 경제발전으로 국민의 소득수준이 올라감에 따라 기본적인 욕구가 해결되어 이제는 납세자로서 국민의 동의는 국가의 정책을 결정하는데 중요한 변수로 작용하기 시작했다. 따라서 사용자 관점의 평가는 이러한 요구의 수준을 측정할 수 있는 중요한 척도가 되었으며 이에 기반한 LoS(Level of Service, 서비스 수준)라는 지수를 시설물 자산관리에 활용하려는 여러 가지 시도가 있다. 이 논문에서는 기존 국도포장관리시스템의 정보모델과 KTAM-40(Korea Total Asset Management-40)이라는 자산관리 정보모델을 비교하여 LoS의 필요성과 도로포장자산관리에서 LoS가 사용자 관점을 반영하는 방식을 조명해 이의 장점을 밝히고자 한다.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.190-198
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• 2009

This study shows the developing process of the risk assessment models for railway casualty accidents. To evaluate the risks of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. The frequency of each hazardous event was evaluated from the historical accident data and structured expert judgments by using the Fault Tree Analysis (FTA) technique. In addition, to assess the severity of each hazardous event, the ETA (Event Tree Analysis) technique and other safety techniques were applied. The risk assessment models developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.