• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.815-822
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• 2006

It is very important that they accurately predict the software development cost in the early stage of a software development. Because cost estimations are required when bidding for a contract or determining whether a project is feasible in terms of a cost-benefit analysis. The criterions of the software cost estimation was set up to calculate software development cost more exactly, which is applied to made up a budget of the software business or to calculate a suitable cost to start the business in our country. However, as the software technology and environment are changing very rapidly, it need to enhance the criterion of the cost estimation continuously. Therefore, we tried to apply technology of software and a variety of factors of environment changes in present. Most of all, we proposed an introduction and readjustment of the adjustment factor applying 14 general system characteristics to improve the accuracy of the cost estimation and the schedule adjustment factor that is required by practicians. For evaluating the accuracy in terms of the real data, we have used MMRE & PRED. In result, we proved that the accuracy was clearly improved by applying the scale factor and readjusted VAF with 14 general system characteristics. Moreover, we evaluated the accuracy of the schedule adjustment factor.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.205-212
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• 2020

Objectives: The purpose of this study was to identify the needs and improvement measures of the risk assessment system through a survey of asbestos abatement companies. Methods: This study prepared a questionnaire that includes improvement measures for the risk assessment system(six questions) and the necessity of a risk assessment system for asbestos abatement(one question). The questionnaire was sent to 2,170 asbestos abatement companies and returned by 83 companies(return rate = 3.8%). We conducted frequency analysis, ANOVA, and Chi-squared testing at the 5% significance level. Results: This study analyzed the survey results and identified six main opinions on the risk assessment system and improvement measures. First, giving an advantage to companies with a high grade(S and A grades) in public bidding and/or qualification screening showed a similar preference(agree: 50.6%, disagree: 49.4%). Second, 57.6% of the respondents wanted to allow air showers along with water showers for low risk asbestos work. However, 23.2% of the respondents asserted that only a water shower should be allowed since there is no scientific evidence supporting the removal of asbestos by air shower. Third, in order to prevent missing the enrollment of workers, simply submitting a change report should be allowed when any worker is changed (40.0%). Fourth, 43% of the respondents answered that they did not know how to calculate the proper number of negative pressure units. The reasons given were a lack of guidelines or standards(38.9%), inconvenience (36.1%), and absence of education(25%). Fifth, the respondents who were favorable toward the necessity of a risk assessment system gave higher scores compared to unfavorable respondents on the necessity of the management of workers' work history(favorable respondent = 3.96 out of 5, unfavorable respondent = 2.68) and the necessity of professional training for workers(favorable respondent = 3.71, unfavorable respondent = 2.56). Finally, the respondents favorable toward a risk assessment system showed higher scores on the awareness of calculating the proper number of negative pressure units(4.79) compared to unfavorable respondents(3.3). Conclusions: The opinions of asbestos abatement companies identified through the survey in this study can be usefully utilized as fundamental information to improve the risk assessment system.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.6
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• pp.641-652
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• 2001

Most of current internet auction systems are single auction server program that partly automates the function of the conventional auction house. So these systems do not provide sufficient independence, distribution and parallelism between the functions of the conventional auction house. In these suction systems, only some of suction management facilities are automated by the server program, but still users need to execute a repetitive task to monitor the dynamic progress of a certain auction, decide the proper bid price, and submit the bid. Another problem is that they support only the single auctions such as English suction and Dutch auction, but they do not support the double auctions that are superior to the single auction in terms of speed, efficiency, and the fair distribution of profit. In this paper, we present are design and implement of an agent-based continuous double auction system, called CoDABot, in order to overcome the limitations of current auction systems. CoDABot supports the continuous double auction, provides various bidding agents for users to select, and has been implemented with a multi-agent system to realize more independent, and parallel subsystems.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.397-409
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• 2015

The Global Financial Crisis and introduction of International Financial Reporting Standards (IFRS) urged the banks to strengthen their asset qualities. The banks dispose their non performing loans(NPLs) consistently to maintain a sufficient BIS capital adequacy ratio. Accordingly, the interests in auctions, as a disposal method, of real estates that secured for NPLs are on the increasing. This study suggest an alternative for fairness consolidation of real estate auctions which secured for NPLs. First, the impartial entry barriers for NPL sales markets need to be eliminated for fair bidding competition in auctions for real estate that secured for NPLs. In addition, the portion of NPL disposal by real estate auctions need to be expanded. Second, the asymmetry of trade information in the retail markets of NPLs and the abuse of offset by NPL owners' also should be restricted. The Fairness improvement of NPL trading process and real estate auction process that secured for them would of great use in the protection of bidders. Futhermore, it would also contribute to the revitalization of real estate auction markets and the resolution of NPLs of banks through fair disposal of distressed assets.

• Journal of Construction Engineering and Project Management
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• v.5 no.1
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• pp.11-19
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• 2015

This paper presents optimized artificial neural networks (ANNs) claims prediction and decision awareness framework that guides owner organizations in their pre-bid construction project decisions to minimize claims. The framework is composed of two genetic optimization ANNs models: a Claims Impact Prediction Model (CIPM), and a Decision Awareness Model (DAM). The CIPM is composed of three separate ANNs that predict the cost and time impacts of the possible claims that may arise in a project. The models also predict the expected types of relationship between the owner and the contractor based on their behavioral and technical decisions during the bidding phase of the project. The framework is implemented using actual data from international projects in the Middle East and Egypt (projects owned by either public or private local organizations who hired international prime contractors to deliver the projects). Literature review, interviews with pertinent experts in the Middle East, and lessons learned from several international construction projects in Egypt determined the input decision variables of the CIPM. The ANNs training, which has been implemented in a spreadsheet environment, was optimized using genetic algorithm (GA). Different weights were assigned as variables to the different layers of each ANN and the total square error was used as the objective function to be minimized. Data was collected from thirty-two international construction projects in order to train and test the ANNs of the CIPM, which predicted cost overruns, schedule delays, and relationships between contracting parties. A genetic optimization backward analysis technique was then applied to develop the Decision Awareness Model (DAM). The DAM combined the three artificial neural networks of the CIPM to assist project owners in setting optimum values for their behavioral and technical decision variables. It implements an intelligent user-friendly input interface which helps project owners in visualizing the impact of their decisions on the project's total cost, original duration, and expected owner-contractor relationship. The framework presents a unique and transparent hybrid genetic algorithm-ANNs training and testing method. It has been implemented in a spreadsheet environment using MS Excel$^{(R)}$ and EVOLVERTM V.5.5. It provides projects' owners of a decision-support tool that raises their awareness regarding their pre-bid decisions for a construction project.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.5
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• pp.362-370
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• 2016

The weight estimation and calculation of FPSO topsides is first performed at the bidding stage of projects. At this time, it is difficult to estimate and calculate accurately the weight because most of items of FPSO are not apparently defined. Especially, in the case of the pipe rack module, its portion of the total weight and the range of weight variation are large due to special features of piping and electric equipment in the module. Thus, it is very important to estimate and calculate accurately its weight in the task of the weight estimation and calculation of FPSO topsides. In this study, the past data for the weight of the pipe rack module were collected and analyzed, the WBS (Work Breakdown Structure) for the pipe rack module was constructed, and primary variables and secondary variables for developing a weight estimation and calculation model were selected. That is, after analyzing the past data, the volume was selected as the primary variable and the regression analysis was performed based on the variable. Then, several secondary variables were selected and incorporated into a weight estimation and calculation model. At this time, the weight per discipline was assumed from ratios of the total weight. Finally, the weight of the pipe rack module was estimated and calculated by using the developed model. As a result, the deviation from the model was better than that (-20 % ~ 60 %) of other studies about the weight estimation and calculation of FPSO topsides. Thus, the validity and applicability of the weight estimation and calculation of the pipe rack could be checked.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.2
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• pp.63-72
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• 2016

Closed-circuit television(CCTV) is a facility that forms the backbone of the ubiquitous services provided by the Integrated Management Center of the Ministry of Land, Infrastructure and Transport and the Integrated Control Center of the Ministry of the Interior. However, it is installed and managed according to different laws, as it is operated and managed by each department. Moreover, because there are no regulatory grounds for unified management of CCTV, each municipality responsible for the actual management manages it based on the individual standards of each department. Thus, the purpose of this study is to develop a standardized management form to establish an integrated management plan. The author inspected the existing situation by examining the legal system and public data and through hands-on worker interviews, and discovered the managed element by reviewing the specifications of the bidding system. The management form for integrated management comprises the above requirements along with the management histories and linkage of intelligent facilities. A uniform management form for integrated management containing specifications of the CCTVs installed by various departments is created, and is easily searched for facilities to check requirements for joint use. The result of this study can contribute to building the database of facility management system for integrated management of facilities at the integrated management center as well as for a detailed simulation of the selection of location of CCTV depending on the CCTV's specifications.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.741-749
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• 2018

The purpose of this study is to propose a rational and scientific damage calculation model in relation to damages caused by bid rigging in construction projects. Previous studies and precedents in relation to calculating damages from bid rigging suggest that the main issue was the lack of consideration in standards for deciding successful bids, selection of inadequate standard comparative markets, insufficiency in analyzing the appropriateness of competitive bid price influence factors, and absence of calculation model verification. In order to improve on these issues, a damage calculation method on alternative tenders for construction projects was proposed. For this calculation model, first, a standard market adequate to the successful bid selection standards was determined, second, an appropriate factor was selected by analyzing the correlation between competitive bid price influence factors, and third, a regression analysis was conducted on the selected factor. Lastly, this was demonstrated through verification of appropriateness, significance & normality of the proposed model and application of actual bid rigging cases. Through the proposed calculation model, this study seeks to serve as a base to prevent opportunity damages for parties involved in related court cases by early resolution of disputes and relief from issues of unfair damage burdens on a particular party.

• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.303-319
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• 2013

The purpose of this paper in the case of elementary and middle schools in Hwaseong city is that clarify spatial structure by seasonal changes of supply region of school meal foods and changes in food mileage. This paper used account registers of school meal foods of the subject schools as data for this analysis. And this paper analyzed data in March, June, September, and December in order to understand seasonal changes of school meal foods. The spatial structure of school meal foods in elementary and middle schools in Hwaseong city take four with private contracts, limited competition, and bidding quotation by suppliers. With the crops in Hwaseong city, they consist of eco-friendly vegetables in Gyeonggi-do, domestic eco-friendly vegetables and fruits, general vegetables and fruits, and imported processed foods and agricultural products. In case of food mileage, around Hwaseong city, there are spatial structure with about 17 $ton{\cdot}km$, 26 $ton{\cdot}km$, and 11,000 $ton{\cdot}km$ respectively. The spatial structure of school meal foods supplies was determined by difference in feed rate of crops, eco-friendly agricultural products, imported processed foods, and imported agricultural products.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.64-76
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• 2006

Korea's overseas construction industry has been rather depressed by the weakened profitability as well as the sharp decrease of the market shares due to the lack of international competitiveness and the declined international market. There exist a lot of various risks in performing the overseas construction, and especially EPC projects, which entail complicated process from different parts, also require a sophisticated procurement and management skill. Subsequently, to survive in the competitive international market, we need to establish strategies to select potentially profitable projects at the initial stage of bidding process and to mitigate the high degree of risk exposure through contract negotiation and its adjustment. This research discusses the trend of environment in international construction markets. Then, it identifies the key factors that affect the profitability significantly through the structured surveys from 59 actual overseas projects, and it analyzes the key factors by using statistical methods. This research provides the profitability evaluation bases, with which overseas construction participants can forecast and analyze the risk more systematically, by eliciting profit-influencing factors using the result of statistical analysis, literature review and structuring their cause-and-effect relationships. The profitability casual hierarchy structure describes the profitability factors' hierarchy in details and their interrelationships. It also enables us to find out critical factors directly related to profitability aggravation through a qualitative and quantitative analysis. Ultimately, with this hierarchy structure as the base, the research will suggest how to develop the quantitative profitability forecasting model.