• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.897-905
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• 1994

Project Informations Classification System (PICS) can be utilized as a springboard for advanced construction management techniques because it marries informations to networks and maintains a disciplined cost control. The present study attempts to develop a PICS which can be applied in construction management techniques. The frame work largely consists of the three parts such as: (i) development of the tentative Work Breakdown Structure with three divisions, facility calssifications, functional classifications and work classifications, covering the whole areas of civil works, (ii) development of the integrated informations system including the other informations in cost estimating and network scheduling, (iii) construction of relational database system for computer application. The system suggested in the study is found useful for the systematic and uniform management of construction works in the various stages.

• IE interfaces
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• v.19 no.2
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• pp.124-132
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• 2006

The system under study is a single item, multi-echelon distribution system with a capacitated production facility. All the nodes at the downstream ends are demand-sites, i.e., ordered items are delivered to the customers from the node. Also any transshipment depots in the midstream can be demand-sites as well. For a given planning period, at each of demand-site, demand is forecasted and known. Our objective is to minimize the average system cost per period which is the sum of holding and backorder costs in the entire network. Due to the capacity restrictions, it is difficult to establish efficient distribution planning. To overcome such a difficulty and obtain a reasonable and better solution, we convert this problem into a single machine earliness and weighted tardiness scheduling. We propose a simple but cost-effective heuristic for this problem. The experimental results showed that the proposed heuristic obtained much better solutions compared with another approach.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.11-20
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• 2013

This Study includes the information of integrated discussion and economies of scale on local governments' sewerage treatment plant through translog function based on the reality reports of sewerage treatment plant operation published by Ministry of Environment and sewerage statistics data from 2005 to 2010. Based on analysis results from the data of 35 local governments in Jeollanamdo and Jeollabukdo, which are selected as pilot project areas of sewerage facility integration by Ministry of Environment and have low percent of sewered population, it shows the existence of economies of scale. The economies of scale on sewerage treatment show the loss of approximately 22,211 thousand ton/day in sewage treatment, it is 1.7 times compared to the average treatment amount of 35 local governments as of 2010. It means the economies of scale can be achieved by lowering operation cost along with large scale integration in installation, operation and maintenance due to the features of sewerage industry as one of network industry.

• IE interfaces
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• v.13 no.4
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• pp.658-667
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• 2000

Seasonal variation of natural gas demand coupled with rigid and stable import pattern of gas represents the characteristic feature of the Korean Liquified Natural Gas(LNG) industry. This attribute has required a huge amount of investment for the construction of storage facility. Thus, to minimize the supply cost, it is legitimate to reduce storage requirement itself. In this study, we combine three alternative methods to deal with the storage requirement to minimize the supply cost. Those are (1) adding additional storage tanks, (2) inducing large firm customers, and (3) constructing gas-turbine self generation facilities. Methodologically, we employ the mixed integer program (MIP) to optimize the system. The model also consider demand and price-setting scheme in separate modules. From the results, it is shown that if alternatives are combined optimally, a number of storage tanks can be reduced substantially compared with the original capacity plan set by the industry authorities. We perform various sensitivity analyses to check the robustness of the results. The methodology presented in this study can be applied to the other physical network industry, such as hydraulics. The empirical results will shed some light on the rationalization of capacity planning of the Korean natural gas industry.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.193-205
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• 2011

This paper suggests $p$-facility locations in $m$ candidate locations and $n$ areas in optimal cost side(population${\times}$shortest distance). This problem has been classified by NP-complete because there is not a polynomial time algorithm. In this paper, we suggests reverse-delete method that deletes a candidate facility one by one from $p=m$ until $p=2$. As a result of the proposed algorithm for the $5{\times}5$ and $7{\times}7$, the initial solution is obtained. For the Swain's 55-node network, we obtain the optimal solution through a solution improvement process with $p=4$ and it by using the initial solution with $p=5$.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.15-23
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• 1998

This paper concerns the problem of determining the spare inventory level for multi-echelon repairable-item inventory system with finite number of operating items. We consider the system which has several bases and a central depot. When an item fails, it is dispatched to a repair facility and, a spare, if available, is plugged in immediately. When the failed item is repaired, it is sent to the base and either is used to fill a backorder or is stored at a spare inventory point. Using queueing network, we develop an algorithm to find the spare inventory level which minimizes the total expected cost and, simultaneously, satisfies a specified minimum fill rate. The results of the algorithm clearly indicate that the algorithm successfully generate output with optimal solution.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.119.4-119
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• 2001

It is the advantage of PLC that digitalization and networking of existing facility can be organized at low price because there is no need further construction of communication line considering that home appliance, information device and various kind of control devices are digitalized at low price. Moreover, AMR(Automatic Meter Reading) is very attractive to utility company because not only does it reduce the cost of reading meter, but also it can control and monitor the demand for energy. So, it can solve the consumers problem best and easily. It also can be easily realized that the utilities can expand there areas to values-added service through existing network. The performance of the PLC modem which is being developed now is not moven enough and much more test for outdoor modem is needed especially. Therefore, we, KEPRI, concentrate our efforts on configuring AMR system for test and investigation of the actual performance of various kinds ...

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1931-1935
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• 2009

Korean railway network GIS-based information system requires so much cost and time. One of the difficulties is due to the fact that GIS-based information system requires the feature database for GIS, which is generally built manually from many as-built drawing files. In order to build-up database automatically Using GPS coordinates, this study suggests the automatic data conversion from electronic drawings to make feature database for GIS. The proposed method can be applied to build large-scale railway facility management system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.404-411
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• 2004

With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with CPLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.77-83
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• 2013

Nowadays, the limitation of Lighting control and management skills is the excessive cost of equipments, the operational difficulties and wasting energy. To solve this problem is in need of communication and management S/W that is worked out complexly well as a information system of smart lighting energy, which is loaded wireless network facility. This paper made a study od the energy saving technology through energy monitoring and we developed LEIS(Lighting Energy Information Sysem) to converge this one. LEIS is monitoring and control lighting energy data that is collelcted from sensors by Zigbee mesh network and shows lighting use information by visualization to users. It is consists of lighting energy information data base based on LEM(Lighting Energy Metering) information and LEIS Web application, provide function scenario to manage energy optimization through LEIS.