• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.1
• /
• pp.29-36
• /
• 2019

In the past, social insurance premiums, such as national pension and national health insurance, is contained within the costs of construction projects, have been lowered due to price competition of companies participating in the bidding. The government is implementing the "Ex-post settlement system" to improve the problem. Therefore, the purpose of this study is to examine the concept of an Ex-post settlement system and background of its introduction and to identify problems in the management of the system. The problems of the Ex-post settlement system are: 1) avoiding the participation of construction workers, 2) the rigidity of the insurance premium settlement method in construction field, and 3) the cause of direct construction cost reduction. The ways to improve these problems are: 1) excluding social insurance premiums from construction project cost, 2) securing flexibility of the settlement method of insurance premiums in construction field, and 3) expanding the scope of persons eligible to participate in social insurance.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2002.05a
• /
• pp.863-870
• /
• 2002

The current class scheduling has difficulties in reflecting students' preferences for the classes that they want to take and forecasting the demands of classes. Also, it is usually a repetitive and tedious work to allocate classes to limited time and cesourres Although many research studios in task allocation and meeting scheduling intend to solve similar problems, they have limitations to be directly applied to the class-scheduling problem. In this paper. a class scheduling system using multi agents-based negotiation is suggested. This system consists of student agents, professor agents and negotiation agents each agent arts in accordance with its respective human user's preference and performs the repetitive and tedious process instead of the user The suggested system utilizes negotiation cost concept to derive coalition in the agent's negotiation. The negotiation cost is derived from users' bidding prices on classes, where each biding price represents a user's preference on a selected class. The experiments were performed to verify the negotiation model in the scheduling system. The result of the experiment showed that it could produce a feasible scheduling solution minimizing the negotiation cost and reflecting the users' performance. The performance of the experiments was evaluated by a class success ratio.

• Korean Journal of Construction Engineering and Management
• /
• v.7 no.1 s.29
• /
• pp.138-147
• /
• 2006

Construction companies have been interested in the construction duration which importantly affects the performance and the success of the construction projects in accordance with the systemic changes such as five days per week system, introduction of construction duration reduction bidding system and post sale system nowadays. It is also very important to estimate and forecast properly the construction duration as the construction companies compete for the projects in the situation of construction market reduction and the lowest bidding system. Recognizing the importance about the construction duration, the researches about comparing and analyzing or estiamting the construction duration have been performed. However, comparing studies about the construction duraion have been limited to the apartment and office building in domestic area. Many studies about forecasting construction duration have been performed through stochastic analysis and simulations. Little research has been addressed the comparison analysis of the real construction duration about the mix-use building and officetel building which occured according to the changes of the building requirements. Therefore, the objective of this study is to compare and analyze the real construction duration and the hypothetical construction duration about the mix-use building and officetel building of the domestic companies. Moreover, we select the most competitve construction company to get the strengths and analyze the competitive advatages of the construction companies about construction duration.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.5
• /
• pp.108-119
• /
• 2016

Since the introduction of the converted accident rate in Pre-Qualification(PQ) process in 1992, the safety evaluation system has contributed to a reduction of construction accidents and development of the safety management system in public construction projects. As the comprehensive evaluation method the government plans to introduce includes the indicators 'accident rate' and 'death rate per 10,000 workers', the influences on the safety evaluation in the bidding process would be broader in public sector construction projects. However, the current safety evaluation system is operated by different estimating standards in the bidding process. At this point, a study of improvement on the safety evaluation index is required to review its current conditions and to propose its efficient operating method. Therefore, the purpose of this study is to analyze problems of the current safety evaluation system through the questionnaire survey on the qualified workers in construction safety management and to propose an improvement plan for the problems noticed. Our results suggest the standards of the unified process for the safety evaluation index, the size of construction firms needed for accident rate estimation, and the improvement plan for unreported accidents. The proposed improvement plan enables the reasonable estimation and efficient operation of the safety evaluation index, and further, it would contribute to reducing construction accidents through the activation of voluntary safety management by construction firms.

• The Journal of Society for e-Business Studies
• /
• v.7 no.2
• /
• pp.55-68
• /
• 2002

Internet group buying systems have been widely used recently. In those systems, because the reserve price is provided by the buyer, the success rate can be decreased if the reserve price is set too low compared with the normal price. Otherwise, an unsuitable successful bid can be made if the reserve price is set too high based on inaccurate information. Likewise, the seller's providing too high a bid price can deteriorate his/her own successful bid rate, whereas a successful bid with too low a price may make no profit in the sale. Therefore, pricing agents that recommend adequate prices based on the past buying and selling history data can be helpful. In this paper, we propose two kinds of agents. One suggests reserve prices to buyers based on the past buying history database of the system. The other recommends bid prices to a seller based on the past bidding history data of the company using the cost accounting theory. Through performance experiments, we show that the successful bid rate can increase by preventing buyers from making unreasonable reserve prices. Also, we show that, for the seller, the rate of successful bids with appropriate profits can increase. Using the pricing agents, we design and implement an XML-based group buying system.

• Journal of Digital Contents Society
• /
• v.16 no.5
• /
• pp.767-773
• /
• 2015

This study suggests a reliable auction right analysis system that improves the existing auction right analysis in a sense that the system is more applicable to a real economic world. The existing study has used an auction successful bidding price rate and an auction successful contract price for its estimation of the auction right analysis. But in this paper the degree of market vitality which is provided from the commercial zone analysis is used as an input variable so the expected auction price can be estimated and the auction right analysis is conducted in that manner.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04a
• /
• pp.355-357
• /
• 2002

기존 분산객체시스템들은 복잡한 환경 설정.고가의 소프트웨어 구입 등의 문제로 활용에 제약을 받는다. 따라서, 최근에 구현이 쉽고, 표준화되어 있어 이러한 문제를 해결할 수 있는 분산 기술로 SOAP이 많은 관심을 받고있다. 그러나 이러한 분산 기술들은 각각의 표준 환경에서만 운용이 된다. 따라서 본 논문에서는 기존 분산객체시스템과 SOAP 기반 시스템의 상호 운용성을 높일 수 있는 SOAP 브리지를 설계한다. 그리고 SOAP 브리지의 성능 실험을 통해 기존 분산객체시스템과 SOAP 기반 시스템 연동에 성능 저하가 퍼지 않음을 보인다. 또한 이러한 SOAP 브리지를 활용하는 방안으로 대규모 분산시스템인 XML 기반 전자입찰시스템을 구현한다. 이 시스템은 XML과 SOAP 기반이므로, 기존 전자상거래 시스템이 갖는 표준화.확장성의 문제를 해결할 수 있다.

• Journal of Power Electronics
• /
• v.9 no.6
• /
• pp.919-928
• /
• 2009

Microgrids (MGs) are typically comprised of distributed generators (DGs) including renewable energy sources (RESs), storage devices and controllable loads, which can operate in either interconnected or isolated mode from the main distribution grid. This paper introduces a novel dynamic programming (DP) approach to MG optimization which takes into consideration the coordination of energy supply in terms of heat and electricity. The DP method has been applied successfully to several cases in power system operations. In this paper, a special emphasis is placed on the uncontrollability of RESs, the constraints of DGs, and the application of demand response (DR) programs such as directed load control (DLC), interruptible/curtaillable (I/C) service, and/or demand-side bidding (DSB) in the deregulated market. Finally, in order to illustrate the optimization results, this approach is applied to a couple of examples of MGs in a certain configuration. The results also show the maximum profit that can be achieved.

• Architectural research
• /
• v.8 no.1
• /
• pp.69-76
• /
• 2006

The purpose of this study is to suggest policies to improve the price escalation system in a construction contract through a Policy Delphi technique. The Delphi, including two times questionnaires and a group discussion, was conducted by joining 14 experts. Also, the escalation provisions of various countries were examined. Results of the Delphi showed that the minimum fluctuation rate for price escalation was desirable at a level of 3%. To compute the fluctuation rate, calculating the price fluctuation of overall articles was more desirable than using price indices. A bidding date was more reasonable as the initial date of change in price. Losses caused by price change should be shared between contractor and owner; therefore a deduction rate should be introduced in price escalation. Meanwhile, overhead and profit should be adjusted in proportion to the fluctuation rate; but advance payment or the delayed construction amount should be deducted from the adjusted amount.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.698-700
• /
• 2004

Electric power restructuring offers a major change to the vertically integrated utility monopoly. Deregulation has had a great impact on the electric power industry in various countries. Bidding competition is one of the main transaction approaches after deregulation. The energy trading levels between market participants is largely dependent on the short-term price forecasts. This paper presents the short-term System Marginal Price (SMP) forecasting implementation using backpropagation Neural Network in competitive electricity market. Demand and SMP that supplied from Korea Power Exchange (KPX) are used by a input data and then predict SMP. It needs to analysis the input data for accurate prediction.