• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.356-360
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• 2015

In this paper, we design and implement a mobile robot with variable structure for tip-over prevention. The mobile robot is designed for the purpose of stable drive and work in outdoor terrain. The outdoor terrain is rough and uneven. In this terrain, the tip-over of the mobile robot can occur while driving and working. Therefore, the structure of the mobile robot must be designed in consideration of stable drive and work. The proposed structure is defined as an X-shape for overall balance of the mobile robot. The shape is designed by using a multi-level structure for reducing the size of the robot. To verify the effectiveness of the proposed design, we analyze the tip-over characteristics according to the height of gravitational center and the extension length of the robot. Finally, we develop a prototype of the mobile robot with variable structure, taking the results of the tip-over analysis into consideration.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.321-329
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• 2018

Classic braced walls use struts and wales to minimize ground movements induced by deep excavation. However, the installation of struts and wales is a time-consuming process and confines the work space. To secure a work space around the retaining structure, an anchoring system works in conjunction with a braced wall. However, anchoring cannot perform well when the shear strength of soil is low. In such a case, innovative retaining systems are required in excavation. This study proposes an innovative earth-retaining wall that uses in situ soil confined in dual sheet piles as a structural component. A numerical study was conducted to evaluate the stability of the proposed structure in cohesionless dry soil and establish a design chart. The displacement and factor of safety of the structural member were monitored and evaluated. According to the results, an increase in the clearance distance increases the depth of safe excavation. For a conservative design to secure the stability of the earth-retaining structure in cohesionless dry soil, the clearance distance should exceed 2 m, and the embedded depth should exceed 40% of the wall height. The results suggest that the proposed method can be used for 14 m of excavation without any internal support structure. The design chart can be used for the preliminary design of an earth-retaining structure using in situ soil with dual steel sheet piles in cohesionless dry soil.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.64-67
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• 2017

This work dealt with structural safety analysis about sandwich composite structure of automotive floor board. In this work, structural design and analysis of sandwich composite structure for automobile floor board were performed. Firstly, structural design requirement of automobile floor board was investigated. After structural design, the structural analysis of the automobile floor board were performed by the finite element analysis method. It was performed that the stress and displacement analysis at the applied load condition. After structural test of target structure, structural test results were compared with analysis results. Through the structural analysis, it was confirmed that the designed floor board structure is safety.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.71-79
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• 2008

The rebar work is very related to the safety and durability of the building. Recently, the rebar work is produced some serious problems due to the lack of skillful crafts-man and the rising cost of rebar materials. Many papers have dealt with the rebar work of the manufacturing system in plants with a view to improvement those problems. But, the research on the rebar work of the manufacturing system in field is in a insignificant condition. This study presents the following improvement schemes as a result. First, the education strengthening for evaluation on practical affairs, second, the reinforcement of drawing & management in shop drawing and finally the simplification of apartment rebar work in slab. Also, this paper aims at advancing apartment rebar work by the actual condition survey in slab work. The further research will be needed about the whole structure parts such as foundation, wall, girder and rebar truss-deck plate as one of the improvement methods.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.17-24
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• 2013

In order to have market competitiveness in local and global areas, Domestic Marine Leisure Industry business, which is a latecomer in the Marine Leisure industry, should retain a strong market adaptability by reducing time and cost that are required for work of planning, designing, and preparation for product development. To meet above requirements, it is essential that integrated system control extensive marine leisure industry. After ensuring integrated information by figuring out the systematic link between related-industries, the core of this research is to secure information classifications that are not just in the flow of simple serial order, but in that of integration and object-oriented information classifications. For this end, we examine other similar cases in industries using real information system applied to industrial production and Product Lifecycle Management (PLM), Product Data Management (PDM), Digital Manufacturing (DM) and applying the same methodology to review practical application in order to construct the information system, and Work Breakdown Structure (WBS), compared with the case studies. Through this basic task for the marine leisure industry classification system configuration (Work Breakdown Structure, WBS) and utilizing information of driving real companies of marine leisure industry, a unique area of MLWBS (Marine Leisure Work Breakdown Structure, MLWBS) is configured. This Marine Leisure Work Breakdown Structure can be used in various areas of applications like products, design information, engineering, production, purchasing, sales, marketing, AS, utilizing various forms of customer support.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.3
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• pp.733-742
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• 2013

The Korea has significant tidal current energy resources, but it is so hard to work underwater for tidal turbine installation. Therefore commercial diving work is very important for tidal current generator. Also, Jangjuk channel is vary famous as proper area to generate tidal current energy. Nevertheless, no one is studied about characteristics of commercial diving works with installation of tidal current generator. The purpose of this study is to introduce commercial diving with work types and investigate critical limits of diving working under the conditions, which are working only to minutes at slack tide during the neap tide. As the results, work types are five as like mooring installation, OMAS(Offshore Maintenance Access System), support structure installation, cable and turbine installation. Here, the original construction period is expected about 4 months, but the construction take 18 months to complete. The cause of extends construction period is insufficiency of researching tidal current conditions at the site and ignorance of slack tide which need to secure diving working time. Total diving working times are 110th during 18 months, the highest percentage of diving times is turbine installation about 43.6 %, and cable, mooring installation and support structure construction are 27.3 %, 15.5 %, 13.6 %, respectively. On the basis of this study, estimation of times of commercial diving is possible with work types of tidal current power, and has a significance as basic data to determining construction period.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.31-37
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• 2006

The objective of this research is to select the most effective technique from task related techniques(motion & time study, job redesign, physical environment improvement) for improving work efficiency in shipbuilding enterprise. This study consists of several principal steps. The first step is to design critical criteria in evaluating work efficiency in shipbuilding enterprises. The second step is to develop sub-criteria of the critical criteria. The third step is to develop a four level AHP(Analytic Hierarchy Process)structure using the critical criteria, sub-criteria and techniques from task related techniques. The fourth step is to develop the pairwise comparison matrix by each level of AHP structure, which was based on survey data collected at the H heavy industry. And the last step is to select the most effective technique from task related techniques using AHP analysis. The result of AHP analysis has shown clear difference in priority among task related techniques in terms of work efficiency of the shipbuilding enterprise: The reduction of normal time has more importance than the reduction of allowance time, motion & time study techniques are most important for the reduction of normal time, physical environment improvement is most important for the reduction of allowance time as well.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.150-158
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• 2007

As higher and bigger buildings, steel structure is so for a basic building structure. Quality management of the steel frame work is started from pre plan phase. And classification and relation of works is very important in quality management. The purpose of this study is developing a quality management model for the better quality management in a steel frame work. This model consider a interrelationship of works and $input^{\circ}{\S}utput$ information, and based on the actual condition of current quality management.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.223-232
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• 2023

The Work-Study parallel program has been promoted as a key policy to resolve the mismatch between industrial sites and school education and realize a competency-centered society, and as of December 2022, 16,664 companies participated in the training. Learning companies play a very important role as education and training supply organizations that conduct field training. In this study, for the evaluation of learning companies participating in work-study program, the authors derive important factors that determine the quality of on-site education and training by analyzing the cognitive structure of experts in charge of the company and present evaluation indicators for learning enterprises. Therefore, it is intended to lay the foundation for promoting the quality of work-study parallel program.

• JOURNAL OF ELECTRICAL WORLD
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• s.338
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• pp.80-90
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• 2005