• Korean Journal of Construction Engineering and Management
• /
• v.7 no.5
• /
• pp.159-166
• /
• 2006

It was found that Korean Standard of Estimate which has been used as the only basis of cost estimate of public construction projects had some side effects such as jerry-build construction and over-estimation because it failed to reflect the current price and the state-of-the-art construction methods in a changing construction environment. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004. This paper presents analytic criteria and a process model for deducing more current and reasonable historical construction cost for contract items from not only previous contract prices but also all of the other bid prices that were not contracted. The procedure of estimating actual unit cost proposed in this paper focuses on the removal of abnormal values including strategically too low or high prices and the time correction. In addition, basic research is conducted for the correction of actual unit cost through the analysis of fluctuation of bid price depending on bidding types and rates of successful bid. It is anticipated that the effective use of the proposed process model for estimating actual unit cost would make the cost estimation more current and reasonable.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.5
• /
• pp.22-34
• /
• 2016

The Project Delivery System (PDS) is used in mixed way without clear classification from tendering system and the standard itself that can be selected is set with project budget or estimated cost only. Essentially, the PDS should consider and reflect project characteristics and types, internal and external factors for the purpose of improving the lives of citizens and their welfare. However, the current status is not operated flexibly due to the given budget, period and uniform laws and regulations. In order to solve this problem, this study suggests a Decision Support Model to select the optimal PDS for public construction projects. The current problem of the PDS for public construction projects were identified and the application of a decision support model was proposed. Subsequently a decision-making model was suggested for each PDS using the identified factors and linear discriminant function of discriminant analysis. An additional questionnaire survey and actual practical case analysis were carried out to verify the effectiveness and applicability of the model to actual work. It can be used by adjusting the decision support model and detailed factors according to the specific characteristics of public organization, ability of person in charge and project type.

• Korean Journal of Construction Engineering and Management
• /
• v.12 no.2
• /
• pp.3-11
• /
• 2011

There are several causes to recalculate the contract amount in public construction projects. Among them, the escalation clause was introduced in 1969 and now the condition to recalculate the cost is effective after 90 days from the date of contract and the rate of fluctuation should be more than 3% from the date of bidding. The two calculation methods for the rate of fluctuation are item-adjustment and index-adjustment. According to the results of investigation into 4 public institutions and 163 projects, all of them have used the method of index-adjustment and the rate of projects that spend over 6 months obtaining the approval of contract amount adjustment is more than 90%. The reason for spending lots of time is caused by problems of the calculation method on the price fluctuation rate. Therefore, it is necessary that the calculation method should be diversified to cope with the problems and a option of the builder should be expanded as well. Furthermore, if the way to apply correction factors to construction price index and average index based on the producer and consumer price index made by the bank of Korea is added, then the duration will be reduced without additional expenses. This study proposed the diversification of the calculation method using price fluctuation rate and builders' expanded options as improvement on the managerial method of Price Fluctuation System for the prompt and efficient contract amount adjustment.

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.6
• /
• pp.107-116
• /
• 2009

As the Fundamentals of Construction Business Act was revised in December 2004 and its implementing ordinances and enforcement regulations were adjusted in June 2005, the screening system of low price subcontracting has been an obligation to the public owners, having brought about arguments for and against since it enacted in 1983. The statutes for low price subcontracting have been reinforced from this year; for example, it underlines to submit to a project and builds an information network of subcontracting works. The system's original intention was that prevents shoddy and fraudulent constructions caused by low price subcontracting and precludes disturbances of fair trade by screening that whether it satisfies the conditions or not in advance. But, the criterion for the existing low price subcontracting has several issues having held up a true mirror to the real situation. It is arguable to discharge an important task with the primary purpose. This dissertation have researched the problem with a deposit of subcontract and the low price subcontracting basic rate are being used by the criteria for deciding whether it is a low price subcontracting or not, so showing the plan of reformation based on the findings, it wishes to contribute toward making the most of the system's essential intent.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.4
• /
• pp.73-80
• /
• 2007

As BTL(Build-Transfer-Lease) private investment business benchmarking PHI(Private Finance Initiative) of USA and Japan is introduces to Korea since 2005, as a part of supplying high leveled public service and early expanding required facilities for SOC, Value for Money on private investment business from treasury investment business at the beginning gets to be needed. Accordingly, this survey has been conducted in order to analyse BTL projects status, propriety of economic analysis method(VFM analysis, calculation of estimated business expenses, valuation of bidding price, etc.) by business advance phases from the viewpoint of person in charge, necessity of improvement and alternative plants. As the result of conducting cross tabulation analysis and correlation analysis by occupational group, BTL project advance phases and alternative plans for improvement, it is necessary ye prepare standardized service level against business expense and basis for calculating and evaluation operation expenses. Based on the necessity of quantitative analysis (LCC analysis) of VFM, standard for calculating management, maintenance and administration expenses is required. In addition, reliable economic valuation system considering domestic BTL environment should be setup, for business efficiency.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.2
• /
• pp.62-70
• /
• 2014

An apartment house, a private facility, is a house built for many persons to live independently in a building. An apartment house is a building where life damage can happen most in case of a safety accident due to insufficient inspections. However, formal inspections are being realized due to awareness shortage of managing bodies about safety inspection and low-price order-receiving of diagnosing enterprises via the lowest bidding method. This is because it is judged that remarkable costs are inputted in repairs and reinforcement such as maintenance of a structure and that there is a large possibility of human damage in case of a safety accident in a structure. So, this paper aims to derive the points to improve in the current criterion to execute an efficient detailed inspection. As its method, the design price and execution price situation of 66 buildings inspected in detail for recent 3 years for the class 2 facilities in Gwangju Metropolitan City and Jeonranam-do are examined and analyzed. The state2 object buildings to inspect are selected through this. And this paper aims to present the points to improve through the analysis of current problems by evaluating the detailed inspection report and the detailed inspection execution price calculation criterion for the selected 10 apartment houses.

• Communications for Statistical Applications and Methods
• /
• v.17 no.2
• /
• pp.293-308
• /
• 2010

In this paper, we examine the forecasting KOSPI 200 realized volatility by volatility measurements. The empirical investigation for KOSPI 200 daily returns is done during the period from 3 January 2003 to 29 June 2007. Since Korea Exchange(KRX) will launch VKOSPI futures contract in 2010, forecasting VKOSPI can be an important issue. So we analyze which volatility measurements forecast VKOSPI better. To test this hypothesis, we use 5-minute interval returns to measure realized volatilities. Also, we propose a new methodology that reflects the synchronized bidding and simultaneously takes it account the difference between overnight volatility and intra-daily volatility. The t-test and F-test show that our new realized volatility is not only different from the realized volatility by a conventional method at less than 0.01% significance level, also more stable in summary statistics. We use the correlation analysis, regression analysis, cross validation test to investigate the forecast performance. The empirical result shows that the realized volatility we propose is better than other volatilities, including historical volatility, implied volatility, and convention realized volatility, for forecasting VKOSPI. Also, the regression analysis on the predictive abilities for realized volatility, which is measured by our new methodology and conventional one, shows that VKOSPI is an efficient estimator compared to historical volatility and CRR implied volatility.

• Journal of Internet Computing and Services
• /
• v.4 no.5
• /
• pp.11-19
• /
• 2003

Since B2C(Business to Customer) from which e-commerce had originated was replaced by B2B, e-Business has shown fast growth so fa., Recently, e-Procurement by l:n concept is on the development as self-purchase system associated with their own ERP In many conglomerates in the Korean market. However, in order to vitalize e-Biz in the plant industry, we need to set up e-marketplaces where many sellers and buyers can meet each other at the same time, which has become the essential part for success as an expanded business model. In this paper, we expect that the foundation for e-transformation in the plant industry is set up by developing Purchase Process System and related modules as the prerequisite for e-Biz in the plant industry, and this report will provide an exemplary model for e-commerce. The Purchase Process System consists of 1) e-Purchasing Module that manages bidding and contract information based on quotation inquiry, 2) e-Expediting Module that manages information to guarantee the on-time delivery, 3) e-Certification Module that controls user authentification, 4) e-Basic Module that manages the bulletin boards, Q&A, etc.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.6
• /
• pp.107-116
• /
• 2019

Korean construction engineering firms want to pave the way for expansion of overseas markets through the World Bank's Official Development Assistance (ODA) projects as a way to improve their overseas project performance. However, since the World Bank project competes with global companies for limited projects, building partnerships with suitable business partners is essential to gain an upper hand in bidding competition and meet the institutional conditions of the recipient country. In this regard, many network studies have been conducted in the past through Social Network Analysis (SNA), but few have been analyzed based on the process of changes in the network. So, This study collected winning data from the three Southeast Asian countries that ended after the World Bank's ODA project performed smoothly, and established a learning-based link prediction model that reflected the dynamic nature of the network. As a result, the 11 main variables acting on building a cooperative relationship between winning companies were derived and the effect of each variables on the probability value of cooperation between individual links was identified.

• Journal of Science and Technology Studies
• /
• v.19 no.2
• /
• pp.1-40
• /
• 2019

Built upon ethnographic method such as participant observation and in-depth interview, this study analyzes the material culture of electronic flower auctions at Yangjae Flower Market. From the viewpoint of Actor-Network Theory(ANT), this research examines how human actors like dealers and auctioneers interact with nonhuman actors such as market devices and these interactions form networks called "agencement." This research is focused on three main objectives: first, to study how the performance of auctions - i.e. the interactions between auctioneers and dealers - change in the wake of new market devices in the auctions; secondly, to look into what changes artifacts bring to the social relationships between auctioneers and dealers; lastly, to analyze the influence of new market devices on auction price in the market. The results of this research are as follows. First, the appearance of new market devices generates changes in the performance of auctions, which means the change of 'agencement' of flower auctions. Direct interactions between auctioneers and dealers turned into indirect interactions through new market devices. Moreover, the changes in the agencement brought changes to the identity of auctioneers and dealers. Secondly, the new agencement caused by the inflow of new market devices formed the trust between the devices and human actors, which gave rise to the trust in electronic auction and in counterpart actors as well. In addition, new market devices lowered direct interactions between auctioneers and dealers and thus made more equal relationships between the two than before. Lastly, market devices like trading screen reduced the leverage of auctioneers by providing dealers with bidding information previously possessed by auctioneers much openly and dealers were able to decide auction prices in more reasonable and dispassionate manner. Economic agency, power, trust, price, and information in the market is material and sensory.