• Journal of the Korean Geotechnical Society
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• v.27 no.10
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• pp.93-104
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• 2011

In this paper, a numerical procedure of probabilistic steady seepage analysis that considers the spatial variability of soil permeability is presented. The procedure extends the deterministic analysis based on the finite element method to a probabilistic approach that accounts for the uncertainties and spatial variation of the soil permeability. Two-dimensional random fields are generated based on a Karhunen-Lo$\grave{e}$ve expansion in a fashion consistent with a specified marginal distribution function and an autocorrelation function. A Monte Carlo simulation is then used to determine the statistical response based on the random fields. A series of analyses were performed to verify the application potential of the proposed method and to study the effects of uncertainty due to the spatial heterogeneity on the seepage behavior of soil foundation beneath water retaining structure with a single sheet pile wall. The results showed that the probabilistic framework can be used to efficiently consider the various flow patterns caused by the spatial variability of the soil permeability in seepage assessment for a soil foundation beneath water retaining structures.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.97-105
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• 2021

The CM at Risk project, which started with the aim of strengthening the global competitiveness of the domestic construction industry through innovation of ordering system, is being implemented in the form of pilot projects in the public sector. However, it seems that it is necessary to enact related laws and regulations to move to the formal ordering system, and the performance analysis of the project is still insufficient. In this paper, the effectiveness and reliability of the project were verified through the performance analysis of the Pre-Construction Service of the four pilot projects currently being implemented. The results of the study were analyzed in five areas including Team Building, Design Book, Construction Period, VE, and BIM. Through the interview survey, the problems were confirmed and improvement plans were presented. The results of this study are expected to be used as basic data for the legalization of ordering system to be implemented in the future.

• Korean Journal of Construction Engineering and Management
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• v.9 no.4
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• pp.182-192
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• 2008

The purpose of this research is to identify problems and solutions of domestic Life Cycle Cost analysis in BTL(Build-Transfer-Lease), a PFI(Private Finance Initiatives) project. It is expected BTL would be quite effective delivery method for public construction introducing the private's major capital investments and technologies, and obviously LCC analysis is becoming more important factor for success of BTL projects. Nevertheless, there are still some complicated issues in LCC analysis, a technique for selecting the optimal VE(Value Engineering) proposals and estimating OM&R (Operation, Maintenance, & Repair) cost of the buildings, and has been applied limitedly. This research mainly focuses on educational facility, as most frequently delivered by BTL currently, especially with two levels (Alternative LCC and Building LCC) , which is occupied main potion in BTL project. In addition, it identifies four main problems and suggests their solutions through case studies focusing six major factors (WBS, Repair Information, Life Cycle, Time value of money, Repair Information Database, LCC Model) from three projects. Advanced development of this research requires closer partnership between the private / public sectors, and their long term strategies.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.13-25
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• 2009

In this paper, a numerical procedure of probabilistic slope stability analysis that considers the spatial variability of soil properties is presented. The procedure extends the deterministic analysis based on the limit equilibrium method of slices to a probabilistic approach that accounts for the uncertainties and spatial variation of the soil parameters. Making no a priori assumptions about the critical failure surface like the Random Finite Element Method (RFEM), the approach saves the amount of solution time required to perform the analysis. Two-dimensional random fields are generated based on a Karhunen-Lo$\grave{e}$ve expansion in a fashion consistent with a specified marginal distribution function and an autocorrelation function. A Monte Carlo simulation is then used to determine the statistical response based on the random fields. A series of analyses were performed to verify the application potential of the proposed method and to study the effects of uncertainty caused by the spatial heterogeneity on the stability of slope. The results show that the proposed method can efficiently consider the various failure mechanisms caused by the spatial variability of soil property in the probabilistic slope stability assessment.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.155-161
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• 2014

The satisfaction of customers from the design stage of product was investigated and reflected by the stage of important function analysis in the enforcement of technique. The goal of this research is worked one reasonable function analysis of the cost reduction and quality enhancement to spread out by using QFD (Quality Function Development). In the case study, the function analysis of VE under the this theoretical background applied to one personal functional combination stimulator. In order to get our goal, the theoretical and case study was in parallel studied each other. This result shows that the new product by using the satisfaction of customers and the quality function development is pointed out the coincidence of the product value.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.77-97
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• 2010

Market timing is an investment strategy which is used for obtaining excessive return from financial market. In general, detection of market timing means determining when to buy and sell to get excess return from trading. In many market timing systems, trading rules have been used as an engine to generate signals for trade. On the other hand, some researchers proposed the rough set analysis as a proper tool for market timing because it does not generate a signal for trade when the pattern of the market is uncertain by using the control function. The data for the rough set analysis should be discretized of numeric value because the rough set only accepts categorical data for analysis. Discretization searches for proper "cuts" for numeric data that determine intervals. All values that lie within each interval are transformed into same value. In general, there are four methods for data discretization in rough set analysis including equal frequency scaling, expert's knowledge-based discretization, minimum entropy scaling, and na$\ddot{i}$ve and Boolean reasoning-based discretization. Equal frequency scaling fixes a number of intervals and examines the histogram of each variable, then determines cuts so that approximately the same number of samples fall into each of the intervals. Expert's knowledge-based discretization determines cuts according to knowledge of domain experts through literature review or interview with experts. Minimum entropy scaling implements the algorithm based on recursively partitioning the value set of each variable so that a local measure of entropy is optimized. Na$\ddot{i}$ve and Booleanreasoning-based discretization searches categorical values by using Na$\ddot{i}$ve scaling the data, then finds the optimized dicretization thresholds through Boolean reasoning. Although the rough set analysis is promising for market timing, there is little research on the impact of the various data discretization methods on performance from trading using the rough set analysis. In this study, we compare stock market timing models using rough set analysis with various data discretization methods. The research data used in this study are the KOSPI 200 from May 1996 to October 1998. KOSPI 200 is the underlying index of the KOSPI 200 futures which is the first derivative instrument in the Korean stock market. The KOSPI 200 is a market value weighted index which consists of 200 stocks selected by criteria on liquidity and their status in corresponding industry including manufacturing, construction, communication, electricity and gas, distribution and services, and financing. The total number of samples is 660 trading days. In addition, this study uses popular technical indicators as independent variables. The experimental results show that the most profitable method for the training sample is the na$\ddot{i}$ve and Boolean reasoning but the expert's knowledge-based discretization is the most profitable method for the validation sample. In addition, the expert's knowledge-based discretization produced robust performance for both of training and validation sample. We also compared rough set analysis and decision tree. This study experimented C4.5 for the comparison purpose. The results show that rough set analysis with expert's knowledge-based discretization produced more profitable rules than C4.5.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.3-13
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• 2009

When promoting BTL(Build Transfer Lease; below BTL) project, negotiation is a stage of examining observation and reflection of RFP(Request for Proposal below RFP) in terms with facilities, operating and financing. It keeps an important position in whole process. However, there is no consistent guideline or model which helps evaluating the result of negotiation. It is difficult to apprise the quantitative outcome after executing negotiation. Thus, this study presented the Value Engineering -based process and model of estimating the outcome of negotiation for the purpose of estimating and verifying the result of negotiation objectively, Evaluating factors of negotiation were classified into 6 fields, 38 divisions and 135 items, focused on cultural facilities on BTL project. Weight of every factor was estimated, and quantitative checklist was established. This study presented the model which could measure the outcome of negotiation. This result would be a critical checklist before negotiation on BTL project, an index of feedback during negotiation, and also a standard of estimating the outcome after negotiation.

• Korean Journal of Construction Engineering and Management
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• v.3 no.3 s.11
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• pp.58-65
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• 2002

University graduates from construction-related departments are undergoing serious difficulties in getting a job as construction companies are reluctant to employ new personnel due to the depression in the construction industry which has been downscaled in both domestic and overseas markets. In the situation is like this, statistics show that the percentage of employment among the university graduates is less than $25\%$, the unemployment problem in the construction sector has started to demand urgent countermeasures. This report anticipated demand and supply for technical man power in the field of construction in between 2002-2008. For preparation of an effectiveness of supply and demand plan on over-supplied in construction technical man power, this suggested expansion of SOC investment, induced into IT field of unemployed construction manpower, enlargement of overseas construction manpower And this considered an elastic operation of curriculum related to construction, and arranged an excess supply and demand of construction technical manpower, which has been considered to education that will meet with demand of enterprise, etc. on both side of quantity and quality simultaneously.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.965-972
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• 2014

Attitudes and behavior within the store congestion of the store is a store in any manner affect the formation process of investigating synchronism in the control of the consumer appears to analyze the influence of enemy has its purpose. Store and spatial congestion factor of social behavioral factors also revisit the help of word-of-mouth is. Consumer groups with high and low groups of synchronism suggested. Social attitudes towards the store congestion significantly positive effect that I've shown, it was not significant spatial congestion. During a revisit of action is a statistically significant relationship that I've shown, is a significant effect of word-of-mouth relationship was not significant. Investigating the moderating effects of consumer synchronism result of high consumer groups a significant impact on the social congestion showed, at low spatial influence congestion.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.44-51
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• 2008

Nowadays, the term, Knowledge Management is used at almost all areas and with various scopes and approaches just like a kind of campaign. Knowledge management addressee from a educated individuals to the inter-organizational network. And it also utilized to solve a present problem, to evaluate the past performances of a company or a organization, and to establish a strategy of the future. This study presented a knowledge management model for the construction management company based on comprehensive researches about the knowledge, the knowledge management, the knowledge management company. The results of this study would be helpful for the construction management company which is making efforts to set the knowledge management system up. And it also could be a recommendatory alternative to establish the knowledge management strategy for the company which is preparing for the knowledge management system.