• Smart Structures and Systems
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• 제20권6호
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• pp.697-708
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• 2017

Maintenance plays a critical role in the bridge industry, but actual practices show many limitations because of traditional, 2D-based information systems. It is necessary to develop a new generation of maintenance information management systems for more reliable decision making in bridge maintenance. Enhancing current work processes requires a BIM-based 3D digital model that can use information from the whole lifecycle of a project (design, construction, operation, and maintenance) through continuous exchanges and updates from each stakeholder. This study describes the development of a data scheme for maintenance of cable-stayed bridges. We implemented the proposed system for a cable-stayed bridge and discussed its effectiveness.

• 기술혁신연구
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• 제12권3호
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• pp.135-157
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• 2004

As the speed of technological changes increase with the investment requirements steadily expanding, private firms and government-funded research institutes experience similar pressures with respect to the necessity of risk reduction and technological alliances in R&D activities. This paper first attempts to review previous research in managing R&D projects with large, risky, and long-term investment requirements. Our primary focus is placed on the "fuzzy front-end" (FFE) projects with uncertainties at the investigation and planning stages. We analyze various elements that create FFE conditions, classify them into basic constructs, and suggest tools and methods to deal with FFE conditions. The findings suggest that both initial FFE conditions and the effectiveness of FFE management affect the performance of the project later on, and thus, especially for large projects, we must deal with FFE seriously in a comprehensive manner. We utilize in-depth panel interviews and case studies to approach the research questions.

• Advances in concrete construction
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• 제5권1호
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• pp.1-15
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• 2017

This research project aimed at evaluating experimentally the effect of natural perlite powder as an alternative supplementary cementing material (SCM) on the performance of fiber reinforced self-consolidating repair mortars (FR-SCRMs). For this purpose, four FR-SCRMs mixes incorporating 0%, 10%, 20%, and 30% of natural perlite powder as cement replacements were prepared. The evaluation was based on fresh (slump flow, flow time, and unit weight), hardened (air-dry unit weight, compressive and flexural strengths, dynamic modulus of elasticity), and durability (water absorption test) performances. The results reveal that structural repair mortars confronting the performance requirements of class R4 materials (European Standard EN 1504-3) could be designed using 10%, 20%, and 30% of perlite powder as cement substitutions. Bonding results between repair mortars containing perlite powder and old concrete substrate investigated by the slant shear test showed good interlocking justifying the effectiveness of these produced mortars.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 폐기물 매립지의 공학적 특성과 개량기술
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• pp.19-32
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• 1992

Objectives of this study are : 1) to utilize capillary theory and obtain pore-size distribution profiles from moisture-suction relationships using Laplace theory. 2) to investigate the behavior of Light Non-Aqueous Phase Liquids(LNAPLs) in the subsurface environment and to develop several predictive relationships which can be used to assess the effectiveness of various LNAPLs remediation technologies. The relationship to predict pore-size distribution function expressed in differencial equation is found by using capillary theory. Also, experiments are conducted to : the various LNAPLs subjected to vadose zone drainage, groundwater table drainage, waterflooding with surfactants. The experiments are performed with #2 heating oil, jet fuel. and kerosene. Several relationships have been derived describing the effect of various properties and process parameters on the LNAPL residual saturation.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.672-683
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• 2007

The rapid development of Kuala Lumpur has seen numerous new and high-rise buildings introducing Building Automation System (BAS). Whilst effective application of Knowledge Management (KM) within BAS is the pre-requisite for the achievement of optimum BAS performance, there has been little research undertaken to investigate if have been the case. This paper presents a research undertaken to get a view of how KM applies in BAS in six (6) selected case-study buildings in Kuala Lumpur, all operating with the 'one-system' M&E workstation control BAS. The emergent findings positively suggest that adequate KM approaches were employed within their BAS management processes, but further studies would be necessary to determine the extent of their application and effectiveness.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.224-229
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• 2009

Digital image recognition has been used for steel bridge surface assessment since late 1990s. However, the non-uniform illumination problems such as shades, shadows, and highlights are still challenges in image processing to date. Therefore, this paper develops a new approach to tackle the non-uniform illumination problem for rust image adjustment. The inhomogeneous illumination problem is divided into shades/shadows and highlights in this paper. The proposed BEMD-morphology approach (BMA) utilizes the bidimensional empirical mode decomposition to mitigate the shade/shadow effect, and the morphological processing to detect and replace the highlight area. Finally, the rust image processed with the BMA will be segmented by the K-Means algorithm, one of the most popular and effective methods, to show the effectiveness of illumination adjustment.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1618-1624
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• 2009

Since various methods for repairing and rehabilitating have been applied to damaged bridges to increase their load carrying capacity, many researches on the methods have been widely carried out. In particular, In terms of applicability, strengthening efficiency and economical efficiency, external tendons using lifting hole anchorage system is the most effective method among the aforementioned methods. In order to verify the strengthening effectiveness, flexural experiments on the beams strengthened with external tendons using lifting hole anchorage system were carried out. The experiments were conducted on two groups of systems, the existing and the proposed external tendons using lifting hole anchorage system. In addition, An evaluation on ductility of the beams were conducted in this paper.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.302-309
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• 2009

The effectiveness of Building Information Modeling (BIM) tools and processes has been recognized by the industry and owners are beginning to adopt Triple Bottom Line accounting practices, to enhance economic performance and environmental and social performance. However, the widespread and practical application of Green BIM remains largely unrealized. The authors identify that lack of understanding of the applicability of sustainability metrics to BIM design process is a significant barrier to this adoption. Through literature review this paper outlines the various sustainability metrics available to construction and elaborates on the potential of BIM for sustainable design. The paper maps and correlates applicable concepts of sustainability evaluation systems to BIM and describes the constraints in current BIM tools.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.486-490
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• 2005

Classic construction safety management functions - such as recruitment, training, supervision, etc. - are determined by different conceptions of the role and nature of management effectiveness, and these conceptions are underpinned by related cultural values. This paper attempts to shed some light on in what way, and to what extent, does the national cultural value orientations influence individual preferences for safety management policies and practices. It presents the empirical results of a questionnaire survey administered in Pakistan targeting construction managers with safety management responsibilities. Based on the survey findings, the paper argues that there is a causal link between cultural values' orientations and preferences for, and perceptions of, safety management policies and practices.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.808-813
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• 2022

This study presents the problems of data imbalance, varying difficulties across target objects, and small objects in construction object segmentation for far-field monitoring and utilize compound loss functions to address it. Construction site scenes of assembling scaffolds were analyzed to test the effectiveness of compound loss functions for five construction object classes---workers, hardhats, harnesses, straps, hooks. The challenging problem was mitigated by employing a focal and Jaccard loss terms in the original loss function of LinkNet segmentation model. The findings indicates the importance of the loss function design for model performance on construction site scenes for far-field monitoring.