• 대한산업공학회지
• /
• 제17권1호
• /
• pp.1-8
• /
• 1991

For situations where there are several markets for a product with different profit/cost structures, an economic variables sampling plan is developed for determining the market to ship the lots to. It is assumed that the quality characteristic X is normally distributed with known variability and unknown mean having a normal prior distribution. Profit models are constructed which involve four profit/cost components ; profit from a conforming item, inspection cost, replacement cost, and cost from an accepted nonconforming item. Methods of finding optimal sampling plan are presented and a numerical example is given.

• 대한산업공학회지
• /
• 제2권1호
• /
• pp.85-92
• /
• 1976

In this paper, the employment planning model is developed which is a decision-making model for determining the optimum employment level with respect to varying net manpower requirement for each planing period such that total cost in a planning horizon is minimized. It is constructed as a nonlinear programming model and a dynamic programming model on the basis of studies in the areas of production smoothing and manpower scheduling. Costs for a planning period are categorized into regular wage cost, hiring cost, and overtime cost. The first is a linear function. The other two cost functions are of quadratic nature. The planning horizon of this planning model is intermediate range (five years) for which a fair planning accuracy can be guaranteed. The model considers learning period for each job class. It is simple and an optimum solution can be easily obtained by direct search techniques.

• Asia pacific journal of information systems
• /
• 제16권2호
• /
• pp.69-84
• /
• 2006

Importance of Today's diffusion of integrated hospital information systems is that various and huge amount of data is being accumulated in their database systems. Many researchers have studied utilizing such hospital data. While most researches were conducted mainly for medical diagnosis, there have been insufficient studies to develop medical care cost prediction model, especially using machine learning techniques. In this research, therefore, we built a medical care cost prediction model for cancer patients using CBR (Case-Based Reasoning), one of the machine learning techniques. Its performance was compared with those of Neural Networks and Decision Tree models. As a result of the experiment, the CBR prediction model was shown to be the best in general with respect to error rate and linearity between real values and predicted values. It is believed that the medical care cost prediction model can be utilized for the effective management of limited resources in hospitals.

• 대한산업공학회지
• /
• 제21권4호
• /
• pp.555-570
• /
• 1995

We consider a preventive replacement policy for a cold-standby system with N components, in which only one component is in operation at a time. If the component in operation fails, a standby component is immediately switched into operation. If all components fail, the system fails. The system is inspected at random poins in time to determine whether it is to be replaced or not. If the number of failed components at the time of inspection exceeds a threshold value r, the system is replaced. Otherwise the decision is put off until the next inspection point arrives. Under the cost structure which includes a replacement cost, a system down-time cost and a holding cost of the components, we develop an efficient procedure to find the optimal control values N and r, which minimize the expected cost per unit time.

• 국제초고층학회논문집
• /
• 제10권1호
• /
• pp.29-34
• /
• 2021

Vertical greenery has become an important technological means to improve the ecological environment condition in urban high-density areas, especially in central areas of Chinese cities. The cost of vertical greenery has significantly increased both in the decision-making process of architectural design and in the assessment of the sustainability potential of urban complexes. The estimation and evaluation of the cost of vertical greenery have become important obstacles to multi-party investment in the construction of vertical greenery. Considering the factors of the building typology and full life-cycle cost, this paper constructs an assessment model of vertical greenery in seven types in urban complex, and suggests an optimized approach to vertical greenery in an urban complex.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.259-262
• /
• 2015

Due to the labor-intensiveness, high investment cost, long execution time, frequent change orders, and many stakeholders in a BIM project, a BIM manager is bound to face a lot of risks to make decisions in cost managing process. Since the productivity of a BIM team will affect the execution cost, this study investigates a simple method of assessing the productivity of a BIM team using the working timesheet records of the team. In this research, the productivity of a BIM team is defined as the effective working floor area (in square meters) of BIM uses per labor-time (in man-months) spent by the team. After the applicability of this method is tested by regression analysis using data from 5 real BIM projects in the construction phase, it is found that the simple productivity definition adopted in the method, although easy-to-implement, does not produce a statistically constant productivity value. More research is therefore needed in the future to devise better indicator(s) for assessing the productivity of a BIM team.

• 국제학술발표논문집
• /
• The 5th International Conference on Construction Engineering and Project Management
• /
• pp.169-172
• /
• 2013

Building Information Modeling (BIM) is an effective decision-making platform that helps to save project cost and enhance quality of construction. By generating and linking a wide variety of objects data, BIM can be effectively utilized, and it should be ensured that object properties maintain consistency throughout the project period of design, estimates, construction, maintenance and repair. This study examined how to utilize BIM data in a construction project, by linking cost and schedule data in web environment, to better utilize the information and maintain consistency of the BIM information. To do so, the model integrated WBS data and CBS data, linked them with BIM model to realize 5D simulation in web environment. As a result, cost and schedule data could be simultaneously acquired, and object properties-cost, schedule, location-as well. These are expected to contribute to developing a BIM-based automatic data-processing system in web environment.

• Asia pacific journal of information systems
• /
• 제12권3호
• /
• pp.213-233
• /
• 2002

Recently, a lot of companies intend to make spin-offs as the Internet usage is proliferating in the business area. A spin-off means a small but autonomous company which is thought to show higher profitability rather than it stays under the influence of a mother enterprise. To prove our hypotheses, we collected questionnaire data from 104 companies considering spin-offs. From experiments with Factor Analysis, we found that there exist four factors which decision-makers should consider before deciding spin-offs such as competence of unit, competence of mother company, competence of spin-off company, and support of mother company. After massive experiments with Regression Analysis we also found that there are significant three performance factors such as competence of unit, competence of spin-off company, and support of mother company. The survey also asked about three potential strategies that they may have been following for achieving business objectives: Cost leadership, Focus, and Differentiation, Six benefits factors emerged from this study: External competitiveness, Internal competency, Productivity, Change, Cost saving, and Improvement. External competitiveness was the most important benefit, and it predicted a Differentiation and Focus strategy. Productivity and Improvement also predicted a Differentiation strategy. External competitiveness, Change, and Cost saving predicted a Cost leadership strategy. However, organizations followed Differentiation and Focus strategies significantly more than Cost leadership. The assessment thus sheds light on the link between information strategy and spin off. We hope that based on our results, many companies considering a spin-off can make a right decision and expect higher performance in a turbulent business environment.

• 대한공간정보학회지
• /
• 제10권3호
• /
• pp.99-105
• /
• 2002

국토공간정보에 대한 수요의 증대와 다양화에 대응할 필요성으로 정부는 1995년 5월 제 1차 국가 지리정보시스템(NGIS) 기본계획을 수립하였다. 지금까지 총 7년여에 걸친 국가 지리정보시스템 사업을 통해 다양한 분야의 공간정보관련 사업을 추진하여 왔으나 투자의 효율성과 경제성 확보를 위한 과학적이며 계량적인 평가가 부족하여 투자 타당성분석 및 사업별 대안의 의사결정이 올바르게 시행되지 못하였다. 지리정보시스템(GIS)의 구축시 제안된 대안들의 효과나 비용을 각 항목별로 우선 순위를 결정하고 이를 토대로 최적의 사업을 결정하는 것은 사업의 타당성을 입증하고 예산의 효율성을 제고하는 기본적인 수단이다. 이와 같은 필요성에서 본 논문은 GIS의 구축시 관련된 세부 비용들에 대해 계층분석기법(AHP기법)을 적용하여 일반적인 GIS 사업의 추진 시 구성되는 비용별 중요도를 분석하여 보았다.

• 한국건설관리학회논문집
• /
• 제17권5호
• /
• pp.120-129
• /
• 2016

이용자 비용은 SOC 시설물의 효율적 자산관리를 위한 LCCA에서 시설물의 생애주기, 관리자 비용 그리고 할인율과 함께 반드시 고려되어야 하는 주요한 분석 항목이다. 특히, 도로분야에서는 청소 및 유지보수 등의 공사구간(Work zone)으로 인해 이용자들에게 막대한 지체비용이 발생되는 경우가 많으며, 이와 같은 경우 관리자는 보다 합리적인 의사결정을 위해 관리자비용 뿐만아니라 이용자비용까지도 고려해야만 한다. 그러나 최근까지도 대부분의 의사결정 단계에서 이용자 비용은 고려되지 않고 있으며, 이에 관한 연구들도 활발하지 못한 실정이다. 본 연구에서는 교통류 모형과 교통시설 투자 평가 지침의 직접편익 산정 모델을 이용하여 의사결정 단계에서 필요한 이용자 비용 및 지체비용을 산정 하는 방법론을 제안한다. 그리고 2014년 실제 유지보수가 시행되었던 국도 4개구간에 대해 VISSIM을 이용하여 교통류 모형을 추정하고 제안된 방법론을 토대로 이용자 비용 및 지체비용을 산정하였다. 분석결과, AADT 약 3만대의 A구간은 공사구간 발생 전 평균 17,569천원/$km{\times}day$의 이용자 비용이 발생하는 것으로 분석되었으며, 유지보수로 인해 1차로를 차단 할 경우 추가적으로 평균 10,193천원/$km{\times}day$(158%)의 지체비용이 발생하는 것으로 분석 되었다. AADT 약 2만대의 B구간과 D구간에서는 각각 1,507천원/$km{\times}day$(115%), 1,985천원/$km{\times}day$(119%)의 지체비용이 발생되는 것으로 분석되었으며, AADT 약 1만대의 C구간에서는 262천원/$km{\times}day$(105%)의 지체 비용이 발생하는 것으로 나타났다. 본 연구의 결과는 교통류 모형을 시뮬레이션 기반으로 추정함으로서 실제 적용에는 한계가 있다. 향후 실제 관측 자료를 이용한 적정성 높은 모형의 개발과 시뮬레이션 검증을 통해 적용 가능성을 높이는 연구가 필요할 것으로 판단된다.