• Korean Journal of Construction Engineering and Management
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• v.1 no.1 s.1
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• pp.87-94
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• 2000

Crack sealing, a routine and necessary part of pavement maintenance, is a dangerous, costly, and labor-intensive operation. Within the North America, about ${\$}200$ million is spent annually on crack sealing, with the Texas Department of Transportation (TxDOT) spending about ${\$}7$ million annually (labor alone accounts for over 50 percent of these costs). Prompted by concerns of safety and cost, the University of Texas at Austin, in cooperation with TxDOT and the Federal Highway Administration (FHWA) has developed a unique computer-guided Automated Road Maintenance Machine (ARMM) for pavement crack sealing. In 1999, successful field tests have been undertaken in 8 States around the U.S. This paper first describes significance of the automated crack sealing and technical advances in automated crack sealers including the ARMM, developed in the U.S. It then discusses the ARMM's field implementation and performance evaluation results, and improvements and modifications suggested through the technology evaluation during the field trials. Current research efforts and future work plans in its further development are also presented in this paper.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1289-1298
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• 2014

Pavement crack sealing method, which is one of the methods to maintain and repair the road, prevents the extending of cracks by repairing cracks in its early occurrence and has already been applied to many roadworks in advanced foreign country for a long time. But in the conventional crack sealing method, traffic accidents occur frequently during the repair because it's commonly performed on the heavy traffic road or highway. It also has some difficulties in securing the safety of workers from the risk of burns caused by heated sealant. In an effort to solve these problems, automated pavement crack sealing machines such as ARMM, OCCSM, TTLS have been developed in advanced foreign country since early 1990s. Also APCS in 2004 and ACSTM in 2013 were already developed domestically. However, since these automated crack sealers developed from a number of research institutions have different test-bed conditions and productivity measurement models, it's difficult to compare and evaluate them objectively. In this study, the image processing time of the respective machines and the movement time of each motion on the work process were estimated by using fully autonomous mapping and semi-automatic mapping in order to measure the productivity in the same environmental conditions. In addition, the productivity measurement test-bed reflected domestic road characteristics was designed to estimate and compare the productivity of the automated crack sealing machines.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.230-233
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• 2009

3D(Difficult, Dirty, Dangerous) 산업의 대표적인 산업으로 인식되는 건설업은 현재 노무기능인력의 고령화와 신규 기능인력 육성의 어려움이라는 문제에 당면하였으며, 이러한 3D 산업이라는 이미지의 탈피 및 노동집약적 사업구조에 대한 변화에 대한 대안으로써 타산업과의 융복합을 통한 이미지 쇄신 및 생산성 향상을 위해 자동화 및 정보화를 위한 노력을 경주하고 있다. 본 연구에서는 건설 자동화 및 정보화를 위한 알고리즘 개발 연구방법론에 대한 기초연구로써, 초고층 공사에서의 물류 효율화를 위한 장비간 통신방법에 대한 모델을 설정하고, 해당 모델에 대해 적용 가능한 알고리즘을 도출하는 프로세스를 규명함으로써, 건설 자동화 및 정보화 연구를 진행하는 단계에서 최적화(Optimization)를 위한 알고리즘 규명에 대한 방안을 제시하고자 한다.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.153-161
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• 2004

The systematic material and labor management planning should be established on accomplished EVM data. The matrix method of integrated cost and schedule was used with common category concept according to the construction project control system. The construction project control system was suggested through analyzing process and data modeling based on integrated cost, schedule and material. Information of construction project can be developed the relationship between the field data and the integrated cost, schedule database. Process and data modelling is provide a standard data format which are related to the material, labor management based on integrated cost, schedule database.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.531-534
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• 2004

Cutting work of the concrete pile is an important task to chsh a part of pile head which is compressed with more than $800kgf/cm^{2}$. It is usually performed by a crusher and three to four skilled workers. llecent analysis results of the pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose the end-effector which can effectively break PHC Pile without any longitudinal cracks before developing an automated pile cutting machine having unified grinder and crusher parts. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

• Korean Journal of Labor Studies
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• v.17 no.1
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• pp.177-208
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• 2011

This article examines that how in-house subcontract has been introduced and developed in metal industry in 1970s, focusing typical workplaces in steel industry. That was essential for the capital to insure control mechanism for large number of laborer because of mobilizing a large scale of capital in industrialization of heavy metal industry. In case of Pohang steel industry, this necessity was fulfilled by introduction and imitation of Japanese personnel management by being included of Japanese economic hinterland. This was embodied in both constructing internal labor market for regular workers and introducing in-house subcontracting system for contingent workers at workplaces. This was exceptional comparing in-house subcontracting system in Korean steel industry with in-house subcontracting system in advanced economies, because of disappearing in-house subcontracting system by making internal labor market. And this was closely linked by late development of Korea. Implications of Pohang steel company's case are as follows : first, late development effect in formation of employment system, second, in linking informality of Korean employment system. This implications mean that in-house subcontracting in steel industry is structured as mechanism for personnel management in large factory being influenced by industrialization of heavy industry. In this point, improvements which include wide economic solution beyond labor solution for present problem of in-house subcontracting system is desirable.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.367-376
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• 2012

Crack sealing is a maintenance technique commonly used to prevent water and debris penetration and reduce future degradation in pavement. The conventional crack sealing operations are, however, dangerous, costly, and labor-intensive. Automating crack sealing will improve productivity and quality, and offer safety benefits by getting worker off the road. During the last two decades, several teleoperated and machine-vision assisted systems have been developed to automate the overall process of routing and sealing pavement cracks. However, the developed systems have not been commonly used in the construction sites because of the technical problems. Especially, the performance of end-effector, related to the productivity and quality improvement, is very important factor to improve the practical use of the developed systems. The main objective of this research is to develop an end-effector in automated pavement crack sealing machine and to analyze the technical feasibility of the developed end-effector.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.1
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• pp.77-86
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• 2000

Even manual materials handling tasks(MMHT) is decreasing by adopt of automatic manufacturing system & transportation supporting machine because of increase of productivity, wage lack of labor, safety, in fact working at inclined & complicated slope such as farm, orchard, harbor loading & unloading, logging place and mining place can't be substituted by machine perfectly. So, workers should do MMHT at this place by themselves, lifting on slope can cause much of hazard, include falling. Keeping balance net to slip can be a reason of low back pain(LBP) by overloaded musculoskeletal system but, there's no enough study about lift on slope. Therefore, In this study, we assessed and analyzed change of center of pressure(COP) when lifting on slope by force platform. The result showed that the length lengthen as increasing angle of slope. Especially, the length extremely increased over 15°. Through These basic result, present proper angle boundary, prevent industrial accidents and give proper data not only lifting but also pushing and pulling on slope someday.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.120-129
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• 2011

An installation of the construction lift has a few limitations by many constrains and these have influences on labor productivity, that can be changed by vertical-transportation management. In the super-tall building construction, a management of construction lift operation is one of the most important factor, but existing methodologies depend on skilled practitioners' experiences. And it is true that the expertise resulted by the experiences does not transfer to the next generation. This study is a part of lifting-management simulation development which aims at the optimal construction lift management. A proposed algorithm is focus on lifting time calculation considering an acceleration capability. This research evaluates the result accuracy using comparative analysis on simulation result and field measuring time.

• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.103-112
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• 2012

Republic of Korea is recently becoming an advanced country with increasing standard of living. This is causing a lack of employment in the construction industry because of high labor costs and it is resulting rapid increase in foreign labors. Modular Method of Construction can be defined as 50%~90% of the entire process is completed in factory, and transferred to construction field to install. The main purpose of this process is to minimize the entire process that possibly can be done at construction field in order to maximize the quality. The current local usage of Modular Method of Construction started at Shin Ki Elementary School during 2003 and it is widely used for military facilities. It should be used more because it has strengths of spending short time period to complete and low production costs. It can make a change if Modular Method of Construction is applied. Toyota is currently producing vehicle with conveyor system and if Modular Method of Construction is applied, then it is possible to reduce the waste of labor, and automatic production time. Expansion of the modular Market can be expected by applying this method because it will improve producing costs, high quality, and enforced process. This research tried to solve the problem of factory's manufacturing production by applying local Modular Method of Construction to provide suggestions and analyze the profitability with applied conveyor system. It is depending on produced model, but this research's model will take 20 months including assessment of payback period.