• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.583-593
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• 2022

The harvesting system in South Korea faces the problems of aging workers and high wages, so it is necessary to improve the operation system and train workers to use high-performance forestry machines. This study compared the effectiveness and costs of yarding and processing operations between a multi-operation system using a tower yarder (HAM300) and a processor (KESLA 20SH) with those of a single-system using a forestry combi-machine. A whole-tree (cable) yarding operation was conducted in the clear-cutting area located at Compartment 15, Gwangneung Experimental Forest, National Institute of Forest Science, and the productivity and cost of multi- and single-system were analyzed. The productivity of the single-system was 1.5 m³/PMH and 1.6 m³/PMH higher than that of the multi- system because the single-system produced 1 log/cycle more than the multi-system in the yarding operation. The cost was approximately 12.1% lower for the single-system (￦36,113/m³) than for the multi-system (￦41,065/m³). The costs of the single-system and multi-system were decreased by maximums of 22.6% and 15.9%, respectively, by decreasing the idle time.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.13-19
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• 2015

Continued efforts to build up Safety Management System(SMS) and to improve its efficiency in airports, to which customers have direct access, are taken for granted due to continuous development of the aviation industry in both quantity and quality and rapid growth of air transportation market. This thesis proposed efficient operation methods of SMS for domestic airport organizations including Incheon International Airport(IIA), the largest airport in South Korea, aiming at strengthening aviation safety from the perspective of airport operators who play a pivotal role in service provider SMS. Those are consolidation of the existing safety management organizations and various improvements to promote voluntary incident reporting system. To draw a proposal for the improvements, conducted a research on domestic safety management status, carried out an analysis on operating conditions and did a research on ICAO regulations, domestic legal system as well as statistics data. Relevant studies and researches were also gathered and analyzed. A search for further improvements can also help increase operational efficiency and promoting a higher-level of safety awareness among operators can establish mature safety culture at airports.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.852-858
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• 2011

This paper is aiming to estimate the mutual influence of the stack cooling performances with the operation modes of the thermal management system for the hydrogen fuel cell vehicles. The heat capacity of the thermal management system was measured by varying the operating modes such as stack cooling heat exchanger only (Mode 1), stack cooling and electric devices cooling heat exchangers (Mode 2), and stack cooling and electric devices cooling heat exchangers with an operation of the condenser (Mode 3).As the results, Performance of the thermal management system (TMS) at Mode 3 decreased up to 34.0%, compared with the result of the Mode 1. In addition, in order to optimize the performance of TMS, the entropy change of stack cooling heat exchanger using irreversibility analysis technique was analyzed with the relationship between entropy generation and entering air velocity of the thermal management system.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.3
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• pp.36-46
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• 1993

In CVT vehicle, the engine speed is completely decoupled from the vehicle speed within the range from maximum transmission ratio to minimum transmission ratio. This allows the engine to operate in optimal state(e.g. best fuel economy or maximum power mode.) In this study, the CVT control algorithm for optimal operation of engine is suggested. In order to implement the real time digital control of electro-hydraulic CVT system, a software called CVTCON has been developed. CVTCON also includes the CVT operation module, (2) system test module, (3) system control module and (4) data management module. By using the CVTCON and the electro-hydraulic CVT system, two modes of experiments were carried out: constant throttle opening mode and acceleration mode. From the experimental result, it was found that the algorithm suggested in this study showed optimal operation of the CVT system.

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.282-286
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• 2014

This study is to present an improvement of physical security system operation by survey on the install and operation of physical security system of 90 facilities. The level of CCTV operation is higher than Access Control system and Intrusion Detection System. But the level of maintenance and management of physical security system is low. The rate of install of X-ray Inspection device show the concern on material detection, although the rate is low. The level of install and operation for the Integration of physical security system is low, so integration of security personnel and security system is necessary for the effective operation. For reinforcement of access control management, security gate and preparing of some obstacles are required with RFID.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.113-118
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• 2016

Project management is a tool for smooth operation during a full cycle from the design to normal operation including the schedule, document, and budget management, and document management is an important work for big projects such as the JRTR (Jordan Research and Training Reactor). To manage the various large documents for a research reactor, a project management system was resolved, a project procedure manual was prepared, and a document control system was established. The ANSIM (Advanced Nuclear Safety Information Management) system consists of a document management folder, document container folder, project management folder, organization management folder, and EPC (Engineering, Procurement and Construction) document folder. First, the system composition is a computerized version of the Inter-office Correspondence (IOC), the Document Distribution for Agreement (DDA), Design Documents, and Project Manager Memorandum (PM Memo) works prepared for the research reactor design. Second, it reviews, distributes, and approves design documents in the system and approves those documents to register and supply them to the research reactor user. Third, it integrates the information of the document system-using organization and its members, as well as users' rights regarding the ANSIM document system. Throughout these functions, the ANSIM system has been contributing to the vitalization of united research. Not only did the ANSIM system realize a design document input, data load, and search system and manage KAERI's long-period experience and knowledge information properties using a management strategy, but in doing so, it also contributed to research activation and will actively help in the construction of other nuclear facilities and exports abroad.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.123-130
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• 1999

The bus as a feeder trip should supply equality service to the whole community. But in spite of the change of latent demand to the bus by the variety of regional structural change, the existing bus route can not supply effective feeder service. For cope with the latent demand to the bus, this study establish a concept that frame of the bus operation and management. This study tackled to evidence this fact by analyzing the bus transport problems in terms of the urban growth, and following issues were discussed: 1) the strategy for improvement of bus operation, 2) the land use control which is appropriate for the public transport network, 3) the economical range to justify the bus operation, 4) the allowance for the private transport mode. On the second part of this study, the difference on the bus operation was compared to determine the range within which the bus operation can be justified. This would provide the direction to improve the management for bus operation and fundamental information to develop the bus operation system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.830-837
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• 2015

A study which is to develop the low-cost urban railway system for low-density line such as Gwang-ju subway Line 2 is in progress, and its TCS(Train Control System) is required as an economic system which is able to train operation suitable in low-density line. We have developed the signaling equipment which is configured with automatic block system between stations, and the control center's equipment in order to meet the requirements of TCS mentioned above. In this paper, we propose the control procedure of ATS to be required for train operation management in the low-density line such as Gwang-ju subway Line 2. The control procedure of ATS considered all features such as the requirements analysis for train operation management, the functions of train control system to be applied and the block type. Also, it considered the station(interlocking, passenger, turn-back) type, station control(stop, route, departure, turn-back departure, turn-back) type, and train operation management for exiting and entering depot. The ATS control procedure proposed in this paper has an advantage in the cost and efficiency through unification and optimization of its function. And in cost of operating and maintenance, the ATS system has a feature that can be significantly reduced.

• Health Policy and Management
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• v.8 no.2
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• pp.88-109
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• 1998

The main purpose of this study is to compare the traditional cost system and ABC(Activity Based Cost) system of clinical laboratory department in a hospital. The study subject was 296 services in clinical laboratory from March, 1997 to August, 1997. In a new costing system, cost for a lab test consist of direct cost element, activity based cost element, and allocated common cost element. In a traditional cost system, cost elements included direct cost element and indirect cost allocated based on test volumes The major findings of this research were as follows. 1. In the application of ABC system, total cost was analyzed as follows. Direct cost was 39.3% of total cost. Activity cost and allocation were 20.9% and 39.8%, respectively. The results of analysis to use traditional cost system were as follows. Direct cost was 39.3% and it was as same as the result of direct cost of ABC system. Indirect cost was 60.7%. 2. Activities of clinical laboratory of subject hospital were registration, pre-test operation, test, test result handling, delivery, culture, post-test operation, technical support, management support, and educational support. 3. The differences of the case of higher number of test case being carried out, the cost of ABC system was lower than the cost of traditional cost system. Otherwise in the case of lower number of test case being carried out, the rests have not been appropriately evaluated, and effective management were needed in clinical laboratory.

• Nuclear Engineering and Technology
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• v.40 no.6
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• pp.451-458
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• 2008

After more than 10 years construction, KSTAR (Korea Superconducting Tokamak Advanced Research) had finally completed its assembly in June 2007, and then achieved the goal of first-plasma in July 2008 through the four month's commissioning. KSTAR was constructed with fully superconducting magnets with material of $Nb_3Sn$ and NbTi, and their operation temperatures are maintained below 4.5K by the help of Helium Refrigerator System. During the first-plasma operation, plasmas of maximum current of 133kA and maximum pulse width of 865ms were obtained. The KSTAR Integrated Control System (KICS) has successfully fulfilled its missions of surveillance, device operation, machine protection interlock, and data acquisition and management. These and more were all KSTAR commissioning requirements. For reliable and safe operation of KSTAR, 17 local control systems were developed. Those systems must be integrated into the logically single control system, and operate regardless of their platforms and location installed. In order to meet these requirements, KICS was developed as a network-based distributed system and adopted a new framework, named as EPICS (Experimental Physics and Industrial Control System). Also, KICS has some features in KSTAR operation. It performs not only 24 hour continuous plant operation, but the shot-based real-time feedback control by exchanging the initiatives of operation between a central controller and a plasma control system in accordance with the operation sequence. For the diagnosis and analysis of plasma, 11 types of diagnostic system were implemented in KSTAR, and the acquired data from them were archived using MDSpius (Model Driven System), which is widely used in data management of fusion control systems. This paper will cover the design and implementation of the KSTAR integrated control system and the data management and visualization systems. Commissioning results will be introduced in brief.