• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.359-367
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• 2013

With recent growth of the economy and development of construction technology, the increase of high-rise buildings is appearing rapidly in urban areas. For this reason, the interest in building maintenance has also been increasing. However, it has many safety problems because it is difficult for the workers to access the exterior wall of building. Therefore, the maintenance system of high-rise building stands out as being important issues to be developed, so that a variety of robot systems have been developed to accomplish the building-wall maintenance works. In this paper, the maintenance robots are classified in painting, inspecting, cleaning systems according to the maintenance works. Then, their locomotion and adhesion mechanisms are analyzed including their applicability to the real maintenance works. This study can be used to develop maintenance robotic system that is more efficient and stable than existing ones.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.72-77
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• 2012

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as earth works, drainage works, pavement works, appurtenant works and etc based on accident examples and investigation on actual condition in roads construction work. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

• The Journal of Society for e-Business Studies
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• v.6 no.3
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• pp.149-161
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• 2001

Construction and engineering is one of the world largest industry. Yet, it Is one of the most inefficiently operated industry. Since buildings are not constructed by mass production, construction projects usually require intense communication and collaboration between participants, who are usually widely dispersed. That is the main reason for the inefficiency. eWorks21 that we developed in this research, is a project management system that can improve communication and collaboration among project participants using the Internet. eWorks21 can reduce project life-cycle, costs, and increase revenue, resource utilization, controls, transparency, and competitiveness, which will eventually provide infrastructure for knowledge management of construction projects. In this research, we classified currently available project collaboration systems, and analyzed the benefits gained by using project collaboration systems. Then we describe the implementation of eWorks21, and discuss employment and utilization strategies of project collaboration systems.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.145-149
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• 2015

Objective: This study aims to analyze qualitatively if PTS methods are applicable to the agricultural works of Korea. Background: Many studies on setting standard time have been performed for manufacturing and service industries, not many studies on agricultural work have been carried out domestically and internationally. Method: MTM, MOST, Work Factor, MODAPTS were applied to some agricultural works, and limitations of each method were found out. Results: MTM was found to be more applicable than other methods, except for mental works. Conclusion: In general, many Korean agricultural works need squat postures, which are not taken into account in most of PTS methods. Continuous observation with stop watch is recommended for establishing the standard time for the agricultural works of Korea. Application: The information drawn from this study would be helpful to the farmer safety assurance system being established by Korean government.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1253-1258
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• 2004

A general idea of implementing and managing real-time control on the VDN for rail transit vehicles is presented. In particular, the virtual device network considered in this paper is composed of Ethernet as the data network and LonWorks network as the device (control) network. A LonWorks/IP web server was used as a gateway to realize peer to peer data communication on the virtual device networks. Experimental results are given to validate the suggested architecture.

• International Journal of Safety
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• v.5 no.2
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• pp.6-11
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• 2006

The time delay in servo control on LonWorks/IP Virtual Device Network (VDN) is highly stochastic in nature. LonWorks/IP VDN induced time delay deteriorates the performance and stability of the real-time distributed control system and hinders an effective preventive and predictive maintenance. Especially in real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. In order to guarantee the stability and performance of the system for effective preventive and predictive maintenance, LonWorks/IP VDN induced time delay needs to be predicted and compensated for. In this paper position control simulation of DC servo motor using Zero Phase Error Tracking Controller (ZPETC) as a feedforward controller, and Internal Model Controllers (IMC) based on Smith predictor with disturbance observer as a feedback controller is performed. The validity of the proposed control scheme is demonstrated by comparing the IMC based on Smith predictor with disturbance observer.

• Journal of the Korean Society of Safety
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• v.22 no.5
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• pp.57-64
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• 2007

In the field of domestic construction demolition works, work process management system is left behind compared with that of several advanced countries such as US, Japan and UK. Especially, the problems regarding safety management are more serious in terms of the availability of safety manuals and law system. The analysis results fiom the questionnaire survey and interviews with demolition engineers indicated that current safety management practices in demolition works lack systematic approach and inappropriate in securing labors' safe working environment. In addition, field labors and managers strongly requested the improvement of safety educational system. Grounded upon the analyses results and investigations, suggestions were drawn for the establishment of advanced safety educational system.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.70-75
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• 1999

The purpose of this study is to recycle the waste concrete which is generated in large quantities as crushed stone in construction works. This study deals with the comparative analysis on the construction works and engineering properties of recycled aggregate concrete through physical experiment. The experimental variables are the kinds of aggregates, some different aggregate composition, and W/C ratio(0.40, 0.45, 0.50). It is able to find from the experimental results that the recycled aggregate concrete is good as general concrete on the construction works and engineering propperties. In addition to, the reliable regression analysis equations between compressive strength and various experimental data for recycled aggregate concrete are presented.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.75-80
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• 2015

Typically, robot system configured by articulated robot manipulator with 1 DOF transfer unit is being applied in automotive manufacturing automation process. Especially, 1 DOF transfer unit is necessary to extend workspace of robot manipulator. In this configuration, because transfer unit works only one direction, robot manipulator only works in one side in case of car body painting or sealing automation process. it is necessary three robot manipulator system at least. In this paper, in order to robot manipulator works effectively in car body sealing automation application, we are suggested omni-directional manipulator system and conducted studying on redundancy resolution method to solve manipulability-optimal problem.

• Journal of Drive and Control
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• v.12 no.4
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• pp.41-47
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• 2015

Hydraulic manipulators have been widely used in many different fields due to their high force/torque to inertia ratio. The increased speed of hydraulic manipulators requires solutions to problems ranging from mechanical design to the need to determine a robot model suitable for model-based control. As a solution, this paper presents the integration of SolidWorks with Simscape for designing and controlling hydraulic manipulators. The integration provides a platform for the rapid control prototyping of a hydraulic robot without the need to build actual prototypes. The mechanical drawings of a manipulator are first created using Solidworks and are then imported into Simscape, where the manipulator is represented by connected block diagrams based on the principle of physical modeling. Simulation examples for a 3D manipulator made by KNR SYSTEM INC are verified to show the effectiveness of the presented platform.