• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.6
• /
• pp.1063-1076
• /
• 2017

To improve the productivity of the earthwork, a fleet management system for construction equipment was suggested in previous studies. But there were some gaps between theory and practice. To overcome this problem, some opinions are gathered form experts and field engineers and four improvements have been proposed and reflected in the system. First, the previous system consists of one hardware module, so it is hard to install it at a control office and construction equipment at the same time. The server module for the office and the mobile module for construction equipment are separately developed. Second, the transportation algorithm that is used in the previous system can generate shortest paths for the earthwork distribution, but embankment areas are not gathered. This situation leads to a decrease in compaction productivity. A modified algorithm for earthwork distribution is suggested. Third, the automated coordinate transformation is performed to show the position of construction equipment on the 3D terrain in real-time. Fourth, construction equipment groups should be formed in the initial stage of earthwork and the number of equipment of each groups should be changed by operation status and site environment. But this functions did not work properly in the previous system. This problem is corrected in the proposed system. The improvements can make the proposed system much more realistic one and can leads to an increase in the productivity of earthwork operations.

• Korean Journal of Construction Engineering and Management
• /
• v.18 no.2
• /
• pp.58-70
• /
• 2017

The planning for material lifting operations is one of the key processes in high-rise building construction. Several previous studies have used rough calculations by referring to existing practices or establishing a target value for lifting cycle time or operating rate. Therefore, the purpose of this study is to propose a material lifting process optimization method for reducing the lifting cycle time and increasing the operating rate. In this study, we improve the cyclic operation network (CYCLONE) modeling method that considers the duration and zone information of each work task. This method can be used to hand over work tasks to another crew group in the work process. According to this methodology, this study optimizes the material lifting process, performs a sensitivity analysis, and evaluates the field applicability of the proposed material lifting process optimization method. Therefore, the optimized process was then applied to a high-rise building construction site. The lifting work process time and operating rate for the simulated as - is lifting process data, optimized process data, and field application result data were compared for each lifting height. From this comparison, the effectiveness of the optimization methodology was confirmed.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.2
• /
• pp.95-102
• /
• 2005

Delaying and objection for the construction of storage spent-fuel disposal has prompted to consider expanding on-site storage of spent reactor fuel since it can eliminate the need for costly and difficult shipping and control of the spent fuel completely under the direction of the owner-utility. The dry storage unit developed in Canada can accommodate Korea heavy water reactor fuel elements and become a candidate for the Korean market. In this paper, finite element analysis were carried out in order to investigate the structural behavior of the nuclear spent fuel dry storage system, which is subjected to impact loads such as collision of a truck load and dropping of flask under the irregular operation.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.11a
• /
• pp.140-148
• /
• 2005

The molten carbonate fuel cell (MCFC) is endowed with the high potential especially in future electric power generation industry by its own outstanding characteristics. KEPCO (KEPRI) started a 100 kW MCFC system development program in 1993 and has been executed 100kW system develpilot plant successfully completed first phaseopment by 2005 on the basis of successful results of 25kW system development. In this program, the components and mechanical structure for 100 kW stack and system construction were completed on last year and now system pre - commissioning was being executed. A 100 kW MCFC power plant was constructed at the site of Boryeong Thermal Power Plant. A 100 kW MCFC system has characterized as a high pressure operation mode, CO2 recycle, and externally reforming power generation system. The 100 kW MCFC system consisted with stacks which was made by two 50 kW sub-stacks, 90 cells with 6,000 cm2 active area and BOP including a reformer, a recycle blower, a catalytic burner, an inverter, and etc. The system has been operated from 13th of September on this year and produced 50 kW AC under atmospheric pressure condition and expected to operate by the end of this year.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.64 no.4
• /
• pp.337-342
• /
• 2015

The company of 4 core materials that are needed for photovoltaic generation is located in area around this university in Gunsan, Saemangeum. And also, it was almost completed the value chain about the production of Polysilicon, Ingot, Wafer, modules and the design, construction of generation system. The industry-academy-government has understood that because of the relative companies' production and investment, it leads to a supply and demand of manpower and thus will have field centered manpower education. This program will help the problem of lack of manpower in relative companies by establishing competitive major agreement like vocational education system. Also, the university and the participating company in joint have pushed ahead field business education to make the least of industrial-education's mismatch, the training of professional manpower connected with related industries to make the universities chemical characteristics, companies securing excellent manpower and contributed to the revitalization of the regional economy. In this paper, are aware that photovoltaic industry is a future strategic industry for the country, so we will train the immediately site adapting manpower for the area of photovoltaic material and system as our goal. This is shown results of education operation for 4 years.

• Journal of the Korean Society of Safety
• /
• v.21 no.3 s.75
• /
• pp.67-72
• /
• 2006

This study is to investigate the related materials such as domestic law regulation, research paper, research report, and the other material, and to suggest suitable counter measures, to find out hazard degree for its works of workers and work place through direct survey, in order to determine risk score of each hazardous work which is designated by the Government, without consideration of labour's consciousness against risk level at a site. Therefore, a new questionnaire survey related to the decision of risk level are made and distributed to find out what risk level each worker recognizes. Also, the authors tried to approach reasonable conclusions after discussing reasonability of qualification standard and improving ideas of worker at hazardous work places with worker, faculty member, H&S manager, labour union. And the results show hazard degrees by each work kind of the above: 3.75 for working with machinery, 3.7 for steel structure, 3.5 for operation of tower crane, 3.51 for retaining wall, 3.85 for form work, 3.46 for scaffolding are obtained. This quantified risk can be applied to establishing a reasonable system to keep safe against hazardous works.

• Water Engineering Research
• /
• v.5 no.1
• /
• pp.17-36
• /
• 2004

This paper evaluated the water resources aspect of the operating results of the Daecheong Multipurpose Dam for the last 21 years. The elements that were evaluated included the amount of water supply from the dam. volume of outflow from the regulating dam, changes in the runoff volume at the dam site and downstream, and variations in the water supply capacity of the Daecheong Multipurpose Dam and the Geum River Barrage Dam situated in the estuary. The rainfall-runoff model was used to evaluate the changes in the runoff volume, and the water balance analysis system was used to evaluate the variations in the dams'water supply capacities. The volume of domestic and industrial water supply from the Daecheong Multipurpose Dam increased to 6.1 times for the last 21 years from 61${\times}$$10^6$$m^3$ in 1981 to 375${\times}$$10^6$$m^3$in 2001. The rate of outflow to inflow of the Daecheong Dam was analyzed 1.30 times in dry season, 1.12 times in semi-dry season, and 0.90 times in rainy season. The volume of inflow to the Geum River Barrage Dam down- stream after the dam's construction increased to 1.25 times in dry season and 1.02 times in semi-dry season and decreased to 0.94 times in rainy season. The water supply capacity of the estuary barrage dam almost did not change in cases with or without the Daecheong Multipurpose Dam, but storages were largely affected by the outflows of the Daecheong Multipurpose Dam.

• IE interfaces
• /
• v.15 no.1
• /
• pp.26-39
• /
• 2002

Two key data areas of the integrated production database in computer-integrated manufacturing (CIM) systems are the product structure in the forms of bills of material(BOM) and the process structure in the forms of routings. The great majority of existing information systems regard the BOM and routing as two separate data entities, possibly with some degree of cross-referencing. This paper proposes new information structure called the bills of material and routings(BMR) that logically integrates the BOM and routings for the CIM systems in ship production. The characteristics of ship production are described as: 1) make-to-order production type, 2) combined manufacturing principles (workshop production and construction site production), 3) significant overlapping of design, planning and manufacturing, 4) very long order throughput time, 5) complex product structure and production process. The proposed BMR systematically manages ail parts and operations data needed ship production considering characteristics of ship production. Also, the BMR situated on the integrated production database more efficiently supports interface between engineering and production functions, and integrates a wide variety of functions within production such as production planning, process planning, operation scheduling, material planning, costing etc., and simplifies information flow between sub-systems in CIM systems.

• International Journal of Precision Engineering and Manufacturing
• /
• v.6 no.3
• /
• pp.29-36
• /
• 2005

With the rapid growth of the Internet, the Internet-based robot has been realized by connecting off-line robot to the Internet. However, because the Internet is often irregular and unreliable, the varying time delay in data transmission is a significant problem for the construction of the Internet-based robot system. Thus, this paper is concerned with the development of an Internet-based robot system, which is insensitive to the Internet time delay. For this purpose, the PPS (Position Prediction Simulator) is suggested and implemented on the system. The PPS consists of two parts : the robot position prediction part and the projective virtual scene part. In the robot position prediction part, the robot position is predicted for more accurate operation of the mobile robot, based on the time at which the user's command reaches the robot system. The projective virtual scene part shows the 3D visual information of a remote site, which is obtained through image processing and position prediction. For the verification of this proposed PPS, the robot was moved to follow the planned path under the various network traffic conditions. The simulation and experimental results showed that the path error of the robot motion could be reduced using the developed PPS.

• Journal of Advanced Navigation Technology
• /
• v.22 no.3
• /
• pp.189-197
• /
• 2018

In Korea, most of the land area is composed of mountainous areas, making it difficult to develop airports because there is not enough open space to operate airports or airfields. However, the current development of the air transportation industry and the rapid increase of aviation demand, the construction of the training airfield infrastructure should be more actively reviewed for safe and smooth flight training. In this study, we analyze the actual condition of operation of domestic training airfield and the case study of overseas training site in order to establish appropriate level standard model of training infrastructures. In addition, this study suggests implications for the appropriate scale and operational efficiency of the training flight infrastructure.