• 제목/요약/키워드: Cost Functions

검색결과 1,365건 처리시간 0.025초

복합화력발전기의 운전조합별 비용함수에 관한 연구 (A Study on the Cost Function Based on Operating Modes for Combined Cycle Power Plant)

  • 이재희;윤혁준;오창진;노유림;주성관;유상민;위영민
    • 전기학회논문지
    • /
    • 제67권3호
    • /
    • pp.358-364
    • /
    • 2018
  • In this study, the theoretical methodology is presented for estimating cost function based on operating modes for Combined Cycle Power Plant. The proposed method has estimated cost functions using the relationship between the gas turbine heat input and the output ratio of the steam turbine. In order to verify the proposed method, a regression analysis was performed using the single cost function estimated by the existing performance test method and the cost function for each operating mode estimated by the proposed method. The results of case studies using the 2016 generator input and output data are presented to show the effectiveness of the proposed method.

Cost-Oriented QC and Process-Oriented QC; Which is more Desirable Approach?

  • Lee, Sang-Do;Lee, Dong-Choon
    • 품질경영학회지
    • /
    • 제13권2호
    • /
    • pp.2-7
    • /
    • 1985
  • 본(本) 연구(硏究)에서는 품질관리(品質管理)의 추진(推進)을 비용(費用) 지향적(指向的)인 방법(方法)과 공정지향적(工程指向的)인 방법(方法)으로 대별(大別)하고 각각(各各)의 특징(特徵)을 설명(說明)함과 아울러 비교분석(比較分析) 하였다. 또 현장(現場) Q.C 담당기술자(擔當技術者)들이 품질관리(品質管理)를 실시(實施)함에 있어서 방향(方向)을 모색한다거나 현재(現在) 실시(實施)하고 있는 방법(方法)의 부당성(不當性)을 첵크하기 위한 기준(基準)을 비용함수(費用函數)로서 제시(提示)하였다.

  • PDF

공사별 변동요인을 고려한 적정 감리대가의 산정기준 연구 (A Criterion for Estimating Supervision Cost Considering the Change Factors by Construction Works)

  • 이배호;강인석;이양규
    • 대한토목학회논문집
    • /
    • 제14권5호
    • /
    • pp.1199-1208
    • /
    • 1994
  • 현재 국내의 공사감리제도는 표준적인 기준이 없이 공사비비율방식 및 실비정액가산방식으로 산정되고 있다. 이러한 산정방식에서는 공사의 복잡도나 감리업무량의 범위, 물가상승등에 따른 조정기능이 없는 획일적인 감리대가가 산정되므로, 적정 감리업무의 수행을 위해서는 별도의 객관적인 감리대가 산정기준이 요구된다. 본 연구는 적정 감리대가의 산정을 위하여 개별공사에 따른 위의 변동요인을 고려한 공사별 적정 감리인원수, 감리대가 및 직접경비의 산정기준을 개발하여, 감리의 질적향상과 함께 효과적인 감리가 가능하도록 하는데 목적이 있다. 이를 위하여 국내외 감리제도의 비교분석, 감리업무의 설문조사 및 현장실사자료등의 분석을 통하여 국내실정에 적합한 감리대가 산정방식과 표준적인 기준을 수식화 또는 도표화하여 결과로서 제시하고 있다.

  • PDF

Developing an Integrated Evaluation Technology for Energy- and Cost-Efficient Building Design Based on BIM in the Real-time Manner

  • Park, Jae Wan;Lee, Yun Gil
    • Architectural research
    • /
    • 제16권3호
    • /
    • pp.93-100
    • /
    • 2014
  • Existing BIM(Building Information Modeling) based energy evaluation tools cannot be utilized enough for the potential performance of BIM because most of them have not provided the integrated model for energy evaluation, assessment of the material, cost of the construction, and so on. This research aims to propose and develop a new application, EcoBIM, to support an integrated evaluation of the energy and cost efficiencies of the design alternatives within the design process. The proposed application functions as a BIM-based evaluation system that calculates energy-savings performance as well as the construction cost of the alternatives at the design stage. This study mainly focuses on the possibilities of developing the proposed technology. We also suggest an advanced design process using the proposed system, corresponding to changes of national regulations in Korea. This study deduce that EcoBIM can allow architects to make suitable decisions regarding energy- and cost-efficient designs. The proposed design process will allow architects not only to check the eco-friendly performance of design alternatives but also predict the operation cost in a certain period in the future. EcoBIM can prevent large-scale design changes required to obtain environmental certification and enable the owner to make an informed decision about the initial investment of construction according to the result of the analysis of the energy requirement at the design stage.

Reliability-based Life Cycle Cost Analysis for Optimal Seismic Upgrading of Bridges

  • Alfredo H-S. Ang;Cho, Hyo-Nam;Lim, Jong-Kwon;An, Joong-San
    • Computational Structural Engineering : An International Journal
    • /
    • 제1권1호
    • /
    • pp.59-69
    • /
    • 2001
  • This study is intended to propose a systematic approach for reliability-based assessment of life cycle cost (LCC) effectiveness and economic efficiency for cost-effective seismic upgrading of existing bridges. The LCC function is expressed as the sum of the upgrading cost and all the discounted life cycle damage costs, which is formulated as a function of the Park-Ang damage index and structural damage probability. The damage costs are expressed in terms of direct damage costs such as repair/replacement costs, human losses and property damage costs, and indirect damage costs such as road user costs and indirect regional economic losses. For dealing with a variety of uncertainties associated with earthquake loads and capacities, a simulation-based reliability approach is used. The SMART-DRAIN-2DX, which is a modified version of the well-known DRAIN-2DX, is extended by incor-porating LCC analysis based on the LCC function developed in the study. Economic efficiencies for optimal seismic upgradings of the continuous PC segmental bridges are assessed using the proposed LCC functions and benefit-cost ratio.

  • PDF

항공운송산업의 비용분석을 통한 규모의 경제성 추정;초월대수(Translog)비용함수와 푸리에(Fourier) 신축함수 비교 분석을 중심으로 (Economies of Scale in Multiproduct Firms;Evidence from Air Transport Industry)

  • 김제철;허석민;이동희;이영수
    • 한국항공운항학회지
    • /
    • 제14권4호
    • /
    • pp.38-47
    • /
    • 2006
  • This study analyzes the expense structure of the air transport industry, based on the cost and income data of 18 major airlines, estimates the economic effectiveness of scale and conducts comparative analysis. As for the method of analysis, Translog cost function and the Fourier flexible function were used. The result showed that big companies had the economy of scale based on the Translog cost function, while the Fourier flexible function led to a estimation that expanding the input is not recommended, for the expansion of scale entails the poor economy of scale. It can be presumed that the economy of scale was estimated according to the U shape of the Translog cost function in the given data. On the other hand, the Fourier flexible cost function approaches the unknown function, as it is a Fourier series, and correctly infers the economy of scale based on the analyzed data. As for the flag carrier's economy of scale, it was inferred that the economy of scale existed by any of two functions. Therefore, the conclusion was that further expanding the scale will not cause any problem.

  • PDF

용접 조립보의 최소 생산 비용에 관한 연구 (A Study on the Minimum Production Cost of Welded Built-up Beams)

  • 장창두;서승일
    • 대한조선학회논문집
    • /
    • 제31권3호
    • /
    • pp.154-164
    • /
    • 1994
  • 본 연구에서는 경제적이고, 품질이 우수한 용접 조립보의 생산을 위해 요구되는 조건을 컴퓨터 시뮬레이션 방법 및 최적화 방법을 이용해서 찾고자 한다. 이를 위해 용접 조건과 가열 조건 등 조립보의 생산 과정을 지배하는 변수를 선정하고, 이 변수에 따라 조립보 생산비를 추정할 수 있는 모델을 제시하여, 생산에 따른 제한 조건을 만족시키면서, 생산비가 최소가 되는 생산 변수를 구하였다. 더 나아가서 설계 및 생산의 통합 제어를 위해 용접 조립보의 생산에 따른 총 비용을 산출할 수 있는 추정식을 제시하고, 선급 규정에 따라 설계하는 과정까지 포함하여 최적화를 수행하였다. 또한 곡직가열이 불가능한 경우를 가정하여, 가중치법에 기초한 다목적 최적화 기법을 도입하고 최소 비용과 최소 변형의 절충해를 얻는 방법을 제시하였다.

  • PDF

BIM 기반 견적을 위한 창호공사 내역 작성체계 개선 방안 (Improvement of Bill of Quantities of Door and Window Work for BIM-based Cost Estimation)

  • 김미현;조찬원;윤석헌
    • 한국BIM학회 논문집
    • /
    • 제10권2호
    • /
    • pp.12-20
    • /
    • 2020
  • Recently, interest in BIM technology has been growing in the domestic construction market as the number of construction projects requiring the application of BIM technology has increased. The use of BIM allows the use of various visualization functions through 3D models as well as drawing interference review, quantity calculation and integrated management of information. In particular, estimates of construction costs based on BIM can increase work efficiency by reducing the burden of calculating construction costs and managing them. In order to increase the efficiency of BIM-based cost estimates, it is necessary to improve the correlation between the BoQ(Bill of Quantity) information and the BIM model. For this purpose, the ratio of the amount and item to the detailed construction of the current BoQ was analyzed, especially the problem of the calculation of construction cost in the window work in this study. In addition, we would like to suggest a method for systematically linking the BoQ information with the BIM model by improving the BoQ information structure of the window work. It is expected that this will increase the efficiency of the quantity calculation and analysis work of construction cost of window work. In addition, it is expected that this method will help to analyze and predict changes in construction cost of windows and doors by facility characteristics and type.

3PL을 활용한 제조기업 공급사슬통합 및 녹색물류 실행을 위한 실증적 연구 (Study on the Execution of Green Logistics and Supply Chain Integration for by 3PL for Manufacturing Companies)

  • 임장혁;한영근
    • 대한안전경영과학회지
    • /
    • 제15권4호
    • /
    • pp.233-243
    • /
    • 2013
  • As companies were concerned with developing green logistics and environment, most logistics concerned functions like packaging, loading, storage, transportation and IT studies are active in study. Even if active in research studies, companies still recognized that logistics cost increases as green concepts are applied. For the efficient execution of green logistics management, it is absolutely necessary but difficult to build an optimal logistics system where each function is smoothly interacted through the proper integration and the link of various logistics functions and partners. This study aims to development of green logistics through integration of supply chain functions and partners. With this aim of study, case studies with analysis of embodiment, planning and operations for supply chain of companies are carried out.

그래픽 에디터를 이용한 지능형 전동기 제어반 설계 (A Design of the Intelligent Motor Control Center Using the Graphic Editor)

  • 이성환
    • 전기학회논문지P
    • /
    • 제55권3호
    • /
    • pp.128-132
    • /
    • 2006
  • The previous MCCs(Motor Control Centers) have the demerits of high cost and much manhour for rework because it is impossible for us to standardize the previous MCCs and they have many manual connections. The customers require the products which can operate with the SCADA system by digitalizing the functions of the current MCCs and the systematized products with capability of remote control. To solve these disadvantages and requirements, we developed the Intelligent Motor Control Center. This system has the various functions such as protection, measuring, and communication. Using these functions, we can monitor motor status through communication with the upper system and define the circuit for lowering connection costs according tn starting type and shortening the manufactural period by the graphic editor. The development of this system results in establishment of the competitive structure with domestic area and Perfect automatic monitoring through linkage with the SCADA system.