• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.401-406
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• 1998

This study aimed at the technique for the construction control in braced excavation works. Selecting a case of Kwangju subway works, field observational values were compared with prediction using Plaxis's. Maximum observational values relevant to both horizontal and vertical proved satisfactory in that they were within the criteria. Numerical results by used Plaxis were overestimated greater than observational values, which meant the prediction were safe tendency. .It must be emphasized that displacement measurement for neighboring important structures should be carried out in order to take countermeasure charge for construction methods, in case that the risk or failure was previewed.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.76-83
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• 2004

There is a greater importance for underground work designed and built in the urban areas when it comes to considering the cost-effectiveness and the period of construction commensurate with an increasing trend of skyscrapers. At this stage of underground work, it's extremely necessary to choose a proper earth retaining method. However, a frequent change order during construction happens in Korea where different performers design and construct separately, so there is a great possibility for the change order to affect the aspects of construction cost and period which normally define the outcome of construction work. Therefore, the study has suggested the rational retaining wall method by developing the case-based reasoning model as stool to choose a proper retaining wall method applied at the stage of selecting the earth retaining method. Applying the 'CBR Model' developed in the study to the designing and developing stages of the earth retaining work will contribute to the successful outcomes by decreasing any changes of design from implementing the earth retaining work.

• Journal of the Korea Institute of Building Construction
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• v.16 no.4
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• pp.331-339
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• 2016

According to high-rise, complexation, and enlargement of buildings, various construction methods are being developed, and the significance of construction method selection about main work types has emerged as a major interest. However, it has been pointed out that hand-on workers cannot consider project characteristics carefully, and they lack an objective standard or reference for main construction method selection. Hence, the selection is being made depending on hand-on workers' experience and intuition. To solve this problem, various studies have proceeded for construction method selection of main work types using Artificial Intelligence like Fuzzy, AHP and Case-based reasoning. It is difficult to apply many different kinds of construction method selection to every main work type with consideration for characteristics of work types and condition of a construction site when selecting construction method in the field. Accordingly, this study proposed the decision-making model which can apply to fields easily. Using matrix analysis and liner transformation, this study verified consistency of study models applied in the process of soil retaining selection with a case study.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.136-145
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• 2008

Recently the Ministry of Finance and Economy of Korea launched two new project delivery systems called "Best Value Contract (Design-Bid-Build)" and "Bridging Contract (Design-Build)" in October of 2007 by revising enforcement ordinances of "Act on Contracts to Which the State is a Party". These project delivery systems require the bidders to submit technical proposal adjusted to the project characteristics and objectives for selecting the contractor by evaluating technical proposals. This research aimed to suggest guideline to effectively operate the project delivery systems described above. To reach the goal of the research, the framework of the operation model was developed, which includes the four categories: the standard bidding process, the technical proposal requirements, the technical proposal evaluation criteria, and the award methods. The contents of the four categories above were fulfilled throughout conferring with the advisory experts. In particular, the award methods, which are the important decision-making factor in the perspective of the owner, consist of four types: Low Bid-Fully Qualified, Weighted Criteria, Adjusted Bid, and Adjusted Score. The quantitative features and application criteria of these four types of award methods were suggested throughout the simulation using the virtual case.

• Geomechanics and Engineering
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• v.36 no.3
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• pp.205-215
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• 2024

Manually mapping fractures in construction stone mines is challenging, time-consuming, and hazardous. In this method, there is no physical access to all points. In contrast, digital image processing offers a safe, cost-effective, and fast alternative, with the capability to map all joints. In this study, two methods of detecting the trace of discontinuities using image processing in construction stone mines are presented. To achieve this, we employ two modified Hough transform algorithms and the degree of neighborhood technique. Initially, we introduced a method for selecting the best edge detector and smoothing algorithms. Subsequently, the Canny detector and median smoother were identified as the most efficient tools. To trace discontinuities using the mentioned methods, common preprocessing steps were initially applied to the image. Following this, each of the two algorithms followed a distinct approach. The Hough transform algorithm was first applied to the image, and the traces were represented through line drawings. Subsequently, the Hough transform results were refined using fuzzy clustering and reduced clustering algorithms, along with a novel algorithm known as the farthest points' algorithm. Additionally, we developed another algorithm, the degree of neighborhood, tailored for detecting discontinuity traces in construction stones. After completing the common preprocessing steps, the thinning operation was performed on the target image, and the degree of neighborhood for lineament pixels was determined. Subsequently, short lines were removed, and the discontinuities were determined based on the degree of neighborhood. In the final step, we connected lines that were previously separated using the method to be described. The comparison of results demonstrates that image processing is a suitable tool for identifying rock mass discontinuity traces. Finally, a comparison of two images from different construction stone mines presented at the end of this study reveals that in images with fewer traces of discontinuities and a softer texture, both algorithms effectively detect the discontinuity traces.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.77-85
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• 2019

Reconstruction and remodeling have been introduced as a part of renewal (redevelopment) projects for old apartments built after the mid-1970's and government policies for revitalizing each project has been changed continually. However, the frequent changes of the policies have caused conflicts among business entities in selecting business methods. The conflicts from their early stages have made serious problems in the entire business process. Therefore, this study deduced factors of business selection by applying comparison analysis between the two business projects on how certain factors have an influence on selecting reconstruction and remodeling business projects. Based on the analysis, four categories and 26 factors were finally selected. After then, the priority of each selection factor was deduced through the AHP method and PROMETHEE method used for analysis of relative importance and impact values regarding to the business selection.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.143-150
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• 2004

Nowaday, The tendency of complexity and extension of construction fields increase the need for efficient works managements like a construction management. Consequently, by the introduction of Decision-Making Theories, researches for improving construction field's efficiencies are actively performed. Fuzzy Analytical Hierarchy Process method is invented, so that describes a decision maker's ambiguous linguistic judgment with fuzzy numbers. but most of researches on Fuzzy-AHP use symmetric triangular fuzzy function for estimating each evaluation item with the consequence that exact judgments are impossible. those limits are caused by the point that employed fuzzy ranking methods can not support dissymmetric fuzzy numbers. In this research, we aims to overcome this problem with R.P.R(Relative Preference Ratio) method and suggest improved Fuzzy-AHP method which can use dissymmetric fuzzy triangular numbers.

• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.28-39
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• 2009

Recently, it has been an issue on BPM(Business Process Management, below BPM), which is a sort of business management methods that secures agility and flexibility through sustainable improving and monitoring in a rapid-changing environment. To introduce BPM to construction company we need to set up a procedure for objective, define criteria according to the business structure defined by BPA(Business Process Architecture, below BPA) and analyze works and then select targets. Those BPM target works need to have a close relationship with corporate strategy and to support realizing corporate value. Therefore, this paper will study BPM Target works of construction companies for an effective introduction BPM through questioning from working-level staff. In addition, it will analyze their types and corporate core strategy and BPM target works, then study the main strategy according to BPM target types. And also, this study is expected to help construction companies to choose the business for BPM adoption through analyzing current situation and strategy for business selection when adopting BPM.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.5
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• pp.12-24
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• 2008

With recent emphasis on the creation of environment-friendly new towns, introduction of ecological facilities for habitation and migration of wild animal's species is requested when developing new towns. In order to introduce such facilities, building an eco-network within the site based on the connectivity of the source area and habitats is essential in new town development. Therefore, this study mainly aimed at selecting species targeted for building an eco-network in Pangyo new town, which is intended to be an environment-friendly city. Therefore, criteria for selecting target species were generated. Then, species observed within the site through field surveys and literature review was evaluated based on the selection criteria and items. By totaling the score, a list of appropriate targeted species was finalized. Among species surveyed and observed in the site, appropriate target species that may be selected for Pangyo new town's eco-network include Falco tinnunculus interstinctus, Accipiter soloensis, Picus canus, Paradoxornis webbiana, Parus palustris, Parus ater, Parus major and Passer montanus Egretta in birds, Asiatic chipmunk, Nyctereutes procyonoides in mammals. For Pangyo new town, it is essential to create living environment and build a network for major wild animal species within the site based on target species. This will play a crucial role in building a reasonable ecological network enabling harmonious co-existence between mankind and nature. In order to build an ecological network successfully, follow-up studies need to be conducted on restoration technology and methods required for creating habitats appropriate to target species.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.89-97
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• 2015

In bidding processes conducted by government agencies, local governments or public agencies, budget prices are critical to both ordering bodies and bidders since budget prices are bases for selecting a successful bidder. Since a high budget price goes against ordering bodies and a low one goes against bidders, most ordering bodies adopt a system using multiple preliminary prices for determining a budget price to ensure fair and transparent manners. Discussed are how budget prices change depending on the methods of sampling 15 preliminary prices and the methods of sampling 4 out of 15 prices. Computer simulation is conducted to analyze budget prices for various methods to determine multiple preliminary prices. It is more likely for budget prices to be close to base prices when splitting a range of generating preliminary prices into 15 intervals and taking 4 preliminary prices from 15 intervals than when taking 4 preliminary prices from a whole range. In cases when splitting a range of generating preliminary prices, if we take 2 preliminary prices out of intervals above 100% and take 2 out of intervals below 100%, the expected budget prices are equal to a base price and the standard deviations are about half in comparison with those when taking 4 out of 15 intervals.