• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.267.1-267.1
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• 2013

In modern science and technology, the organization of building blocks, such as spherical particles and zeolite, is important to form a nanostructure. So, it is essential to develop methods for organizing them into large scale for many precise applications. Up to now, reflux and stirring is widely used method for organization of colloidal particles. However, because this method is hard to organize building block with high coverage and uniform orientation, it is necessary to research another method. In this work, we synthesized spherical silica particles using St$\"{o}$ber method and organized them on the glass which is coated with 3-chloropropyltrimethoxysilane (CP-TMS) and polyethyleneimine (PEI) using Sonication method. Although spherical silica particles are difficult to attach on the glass due to their small attachment site, we improved this problem by coating PEI. We introduced two mode of reaction promotion, sonication (SO) and sonication with stacking between the bare glass (SS), and investigated degree of coverage (DOC) and degree of close packing (DCP).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.94-95
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• 2019

Recently, the importance of prevention has emerged for the management of construction safety accidents.. Accordingly, this study collects and quantifies various risk factors at the construction site to represent them as direct risks and to create a predictive process for prevention in advance. These risk figures can be used as comprehensive safety figures to reflect current site conditions and past accidentt cases. The prevention of industrial accidents is managed in advance through the development of applications thatt quantify and predict the risks of individuals working at construction sites. The purpose of the project is to reduce industrial accidents in the construction industry by supporting safety management of site managers and workers.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.16-17
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• 2019

In order to measure the amount of carbon dioxide emitted from the construction sites, many literature which have been conducted have proposed methodologies for calculating coefficients based on actual data collections for estimating the emission formula. The existing data collected under controlled conditions not on site measurement were too limited to apply in actual sites. The purpose of this study is to conduct analysis based on the data measured in fields and to present predictive models using artificial neural network and nonlinear regression analysis for appropriate predictions and practical applications.

• Wind and Structures
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• v.18 no.4
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• pp.375-389
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• 2014

The high-frequency force-balance (HFFB) technique and its subsequent improvements are reviewed in this paper, including a discussion about nonlinear mode shape corrections, multi-force balance measurements, and using HFFB model to identify aeroelastic parameters. To apply the HFFB technique in engineering practice, various validation studies have been conducted. This paper presents the results from an analytical validation study for a simple building with nonlinear mode shapes, three experimental validation studies for more complicated buildings, and a field measurement comparison for a super-tall building in Hong Kong. The results of these validations confirm that the improved HFFB technique is generally adequate for engineering applications. Some technical limitations of HFFB are also discussed in this paper, especially for higher-order mode response that could be considerable for super tall buildings.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.30-35
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• 2021

In this study, a machine simulation system was built using the actual scale of an AC-type 5-axis machine tool for mold surface machining that can be used in applications, such as, modeling and machine building, stroke, and collision detection. The validity of the 5-axis machine simulation system was verified by performing tool path generation, post-processing, machine simulation, prototype motion simulation, and an actual cutting experiment. This entire process was intended to activate the 5-axis machining in mold surface machining.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.687-692
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• 2005

The Building and Construction Industry Security of Payment Act 1999 (NSW) (the Act) is a unique form of statutory regulation for the building and construction industry, which gives virtually all industry participants a statutory right to, and a means of recovering, payments for work done under a construction contract. The research aim is to examine current trends in adjudication applications and determinations under the Act. The research reveals: (a) that the adjudication process is encouraging parties to resolve disputes as to payment (b) that there is low level of awareness and understanding of the provisions of the Act, particularly amongst subcontractors; (c) that claimants making small claims experience a high rate of success at adjudication; and (d) that the indirect cost of adjudication is becoming problematic.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1233-1241
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• 2023

This paper investigates the efficient application of drone LiDAR technology for acquiring precise point cloud data in construction and civil engineering. A structured workflow encompassing data acquisition, processing, and accuracy verification is introduced. Practical testing on a construction site affirms that drone LiDAR surveying yields accurate and reliable data across various applications. With a focus on accuracy and verification, the results contribute to the progression of surveying methodologies in construction and civil engineering. The findings provide valuable insights into the dynamic technological landscape of these fields, establishing a foundation for more effective and precise surveying techniques. This study underscores the transformative potential of drone LiDAR technology in shaping the future of construction and civil engineering survey practices.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.123-124
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• 2023

This study successfully developed a chromium-free paper-based analytical device (µPAD) for chloride detection in fresh concrete. The sensing materials were chemically synthesized and coated to the paper through drop casting. The fabricated µPAD was thoroughly tested with various concentrations of chloride ions. Upon interaction with the µPAD, the chloride ions in the solution react with a chromium-free silver compound, exhibiting a specific coloring height proportional to the absolute chloride concentration. The height of the color change during a reaction can vary based on the chloride concentration, which allows for predicting the chloride concentration in a solution. The results reveal that µPAD has extraordinary precision in identifying chloride in fresh concrete, which highlights its immense potential for future applications.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.457-464
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• 2013

Traditionally, the material used for the form in reinforced concrete construction has been wood or steel. But recently, aluminum forms have been widely used in wall structures such as apartment buildings. Aluminum is light, easy to handle, and economically advantageous, but the hydrogen gas created due to its reaction with the alkali component in concrete gives rise to air pockets on the concrete's surface, and deteriorates the surface's finishability. In this research, to determine the influence of aluminum material on concrete, the cement paste W/C and its chemical reactivity in alkali and acid solution were analyzed. As a prevention plan, the influence of the number of applications of calcium hydroxide and various surface coating materials was analyzed. Through the analysis, it was found that the surface voids on the aluminum form are the result of the reaction of hydrogen gas with an alkali such as $Ca(OH)_2$. This can be prevented by the surface treatment of $Ca(OH)_2$, separating material and coating material. However, poor surface form and damages to the form are expected to cause quality degradation because of the aluminum-concrete interaction. Therefore, thorough surface treatment, rather than the type of separating material or coating material, is considered the most important target of management.

• Journal of Contemporary Eastern Asia
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• v.13 no.1
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• pp.69-81
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• 2014

While much in the field of public management has emphasized the importance of nonprofit advocacy activities in policy and decision-making procedures, few have considered the relevance and impact of leading actors on structuring diverse patterns of information sharing and communication through social media. Building nonprofit advocacy is a complicated process for a single organization to undertake, but social media applications such as Facebook and Twitter have facilitated nonprofit organizations and stakeholders to effectively share information and communicate with each other for identifying their mission as it relates to environmental issues. By analyzing the Australian Marine Conservation Society's (AMCS) Twitter network data from the period 1 April to 20 April, 2013, this research discovered diverse patterns in nonprofit advocacy by leading actors in building advocacy. Based on the webometrics approach, analysis results show that nonprofit advocacy through social media is structured by dynamic information flows and intercommunications among participants and followers of the AMCS. Also, the findings indicate that the news media and international and domestic nonprofit organizations have a leading role in building nonprofit advocacy by clustering with their followers.