• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.780-785
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• 2005

This paper aims to consider an overall benefit-duration optimization (OBDO) problem for the sake of maximizing owner's economic benefits, whilst considering influences of schedule compression incurred opportunity income on the profitability of a large-scale construction project. Unlike previous schedule optimization models and techniques that have focused on project duration or cost minimization, with greater weight on contractors' interests, OBDO facilitates owner's economic benefits through overall benefit-duration optimization. In this paper, the objective function of OBDO model is formulated. An example is illustrated to prove the feasibility and practicability of the overall benefit-duration optimization problem. The significance of employing OBDO model and future research work are also described.

• 한국산학기술학회논문지
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• 제17권4호
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• pp.19-25
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• 2016

사회기반시설물을 포함한 구조물은 수명유지 또는 연장을 위하여 적절한 점검과 유지보수가 필수적이다. 이러한 점검과 유지보수는 일반적으로 생애주기비용 평가를 통해 관련 계획이 수립된다. 본 논문에서는 구조물의 생애주기비용과 그 사용으로 인해 발생되는 이익을 고려하는 확률론적 비용-이익분석과 이를 통한 구조물 최적수명 결정 방법을 다루고자 한다. 생애주기비용은 구조물 초기 제작/건설비용, 유지보수 비용과 구조물 파괴로 인한 예상손실을 고려하게 된다. 일반적으로 구조물의 수명연장은 생애주기비용의 증가를 유발하나 사용기간 증가로 인해 발생되는 이익 또한 증가하여, 이를 최적화하는 수명관리에 관심을 가질 필요가 있다. 생애주기 평가에 있어서 유지보수 적용이 구조성능, 구조물 파괴확률 그리고 수명에 미치는 영향을 확률론적 방법을 적용하여 평가하며, 이를 통해 생애주기비용과 이익의 차이를 목적함수로 구성하게 된다. 이 목적함수가 최대가 되는 지점이 설계변수인 구조물 최적수명이 되는데, 최적화문제 구성에 있어서 제한조건의 변화에 따라 유지보수 계획수립도 가능하다. 본 논문에서 다루어지는 구조물 수명관리 최적화기법이 안전성과 효율성을 동시에 고려하는 사회기반시설물 수명관리에 기여할 것으로 기대한다.

• 경영과학
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• 제27권1호
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• pp.45-60
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• 2010

This study evaluates life annuity plans based on two different types of measures : financial benefit and utility on consumption. The financial benefit is measured by Money's Worth (MW) ratio and return on annuity. For the measure of utility, an optimization problem is formulated with the objective of maximizing utility on consumption. To solve the optimization model, we use Dynamic Programming (DP) technique. The both types of measures are applied to cases of Korean pre-retirees at age 40 with different accumulation years of annuity (i.e. level of annuity asset at the age of retirement) and different timings of annuitization. Our results generally indicate that the utility based optimization model is superior to the financial measures in terms of providing a better evaluation of an annuity plan due to its capability to consider an individual's financial situation during his/her retirement period. Also, they suggest that the level of annuity asset is an important factor when an individual determines the optimal annuitization timing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.581-583
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• 1995

This paper presents a theory on the pricing and allocation of spinning reserve. It is shown in this paper, that it is possible to maintain system security with many participants each attempting to optimize their own benefit, through pricing incentive. Participant offers power consumption/generation and reserve contribution according to its price. And Price setter only distribute pricing signal to acquire system security. Participants induce disturbance on power system and they pay the penalty according to the size of disturbance. And they also offers some reserve capacity to earn reserve cost. In this scheme, the amount of data communication is very small.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.933-935
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• 1997

This paper presents a new approach to dispersed generation installation planning based on a Hereford Ranch Algorithm in a subtransmission system. A method to optimally locate dispersed generations in a meshed network for maximizing the potential benefits is outlined using Hereford Ranch Algorithm and its improvement in this paper. The benefit expressed as a performance index can be minimization of losses. The proposed method was tested for several sample power systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1301-1318
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• 2017

In order to utilize the licensed channel of cognitive radio (CR) when the primary user (PU) is detected busy, a benefit-exchange access mode based on cooperative communication is proposed to allow secondary user (SU) to access the busy channel through giving assistance to PU's communication in exchange for some transmission bandwidth. A holistic joint optimization problem is formulated to maximize the total throughput of CR system through jointly optimizing the parameters of cooperative spectrum sensing (CSS), including the local sensing time, the pre-configured sensing decision threshold, the forward power of cooperative communication, and the bandwidth and transmission power allocated to SUs in benefit-exchange access mode and traditional access mode, respectively. To solve this complex problem, a combination of bi-level optimization, interior-point optimization and exhaustive optimization is proposed. Simulation results show that, compared with the tradition throughput maximizing model (TTMM), the proposed holistic joint optimization model (HJOM) can make use of the channel effectively even if PU is busy, and the total throughput of CR obtains a considerable improvement by HJOM.

• 방송공학회논문지
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• 제12권5호
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• pp.423-434
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• 2007

본 연구에서는 방송콘텐츠 OSMU(One Source Multi Use, 원소스멀티유즈)의 현황 파악을 통해 OSMU의 개념적 틀을 정립하고, 한미 양국 간 사례분석을 실시함으로써 향후 방송 콘텐츠의 OSMU의 경쟁력 향상 방향을 논의하고자 한다. 연구를 통해 우선 국내에서 통용되고 있는 OSMU의 어원과 개념 및 기존이론 고찰을 통해 방송콘텐츠 OSMU 명확한 개념을 정립함과 동시에 새로운 비즈니스 분류를 도출해냈다. 또한 개발된 OSMU 분류에 따라 한국과 미국의 대표사례를 선정하여 분석하였으며, 이러한 과정에서 산업전문가들과의 간담회 및 인터뷰가 함께 이루어졌다. 마지막으로 도출된 연구결과를 바탕으로 향후 방송 콘텐츠의 OSMU의 경쟁력 향상 방향을 제시하고자 한다.

• 자원ㆍ환경경제연구
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• 제12권1호
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• pp.75-90
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• 2003

본 연구는 도로혼잡의 외부효과를 제거하기 위한 정책방안으로 선행연구들이 제안한 피구세의 타당성 여부를 편익측면의 분석을 통해 재조명하고 있다. 본 연구는 예산제약 조건과 시간제약 조건하의 효용극대화 모형을 이용하여 고속도로 이용을 통해 얻을 수 있는 사적 한계편익과 사회적 한계편익을 규명하고 있다. 그 결과 본 연구는 사적 한계편익과 사회적 한계편익의 차이인 외부 시간비용 만큼을 피구세로 부과할 것을 제안하고 있다. 이 때 외부 시간비용은 고속도로 혼잡으로 인해 고속도로 이용자가 추가로 부담하는 한계시간비용의 가치를 나타낸다. 그리고 본 연구는 효용 극대화 모형을 통해 도출한 피구세의 크기와 이윤(또는 부)의 극대화를 통해 선행연구들이 도출한 피구세의 크기가 동일하다는 사실을 이론적으로 보여주고 있다. 아울러 본 연구는 효용극대화 모형을 통하여 사회적 평균혼잡비용과 사적 한계혼잡비용이 일치한다는 사실도 동시에 보이고 있다.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.493-504
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• 2011

The present paper presents a genetic algorithm (GA) to maximize social welfare and perform congestion management by optimally placing and sizing one Thyristor-Controlled Series Capacitor (TCSC) device in a double-sided auction market. Simulation results, with line flow constraints before and after the compensation, are compared through the Sequential Quadratic Programming SQP method, and are used to analyze the effect of TCSC on the congestion levels of modified IEEE 14-bus and 30-bus test systems. Quadratic, smooth and nonsmooth (with sine components due to valve point loading effect) generator cost curves, and quadratic smooth consumer benefit functions are considered. The main aims of the present study are the inclusion of customer benefit in the social welfare maximization and congestion management objective function, the consideration of nonsmooth generator characteristics, and the optimal locating and sizing of the TCSC using real code-based GA to guarantee fast convergence to the best solution.

• Journal of Korea Trade
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• 제23권3호
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• pp.84-104
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• 2019

Purpose - This paper explains why free trade agreements (FTAs) are more popular than customs unions (CUs) in respect of tariff coordination. Design/methodology - This paper employs an equilibrium theory of trade agreements with tariff coordination. I set up three-country partial equilibrium model with competing exporters. Domestic and exporting firms decide their optimal production under given tariffs and each country levies its tariff under the trade agreements. I found stability of implicit tariff coordination and preference of each country between an FTA and a CU. Findings - I demonstrate that two FTA members can keep their external tariffs higher than separately decided external tariffs by keeping the status-quo. This implicit tariff coordination can benefit each member through trade diversion. In a CU, each member country must have a common optimal external tariff and it must incur costs because each country may seek different external tariffs for their own national welfare. The benefit of implicit coordination in an FTA and the cost of explicit coordination in a CU account for the popularity of the FTA. Originality/value - This paper uses the idea of implicit tariff coordination in trade agreements. In a CU, tariff coordination is explicit and mandatory. All member countries must have a single common external tariff for each good. On the other hand, in an FTA, each country establishes its external tariff with the goal of maximizing its own welfare. However, each country can also coordinate "implicitly" by keeping the status-quo after establishing an FTA.