• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.324-330
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• 2015

Energy Saving Methods in existing railway vehicle are considered by active approach such as regenerative energy storage and utilization, eco driving, etc. On the other hands, energy saving measures in railway station are operated by passive method such as reduction of operating time in ventilation system, cooing system and power equipment. To reduce energy and for independence in railway system, it requires an active energy saving measures. It needs to its own power source besides the power source of electric supply company such as renewable energy and regenerative energy and take the advantage of power storage system and stored power are used in optimum time. This paper deal with 3-level NPC inverter and T-type NPC inverter that used in various multi-level topology applicable to the railway system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.3
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• pp.110-116
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• 2017

System to automate the trial-run of energy storage system for frequency regulation was developed and demonstrated. Basic strategy was developed on the basis of trial-run procedure and verified in the computer simulation tool. The algorithm was developed and coded for 4MW trial-run automation system. 4MW trial-run automation system was connected to 4MW energy storage system for frequency regulation in Jocheon substation of Jeju city and demonstrated. 24MW trial-run automation system was developed on the basis of 4MW trial-run automation system and verified by operation system for 24MW energy storage system for frequency regulation. The operation system has own simulation model of energy storage system and power system. The verification was performed to improve the system in the view of user. 24MW trial-run automation system was demonstrated in 32MW Ul-san and 36MW Non-gong energy storage system. All tests of trial-run was done by manual and first they ware taken 1 week with no trial-run automation system. The manual trial-run tests were taken by maximum three times. Trial-run test by trial-run automation system was taken 2 days. The system helps reduce the trial-run test period and improve the accuracy of tests.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1859-1864
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• 2004

An effective methodology is reported for the optimal design of multisite batch production/transportation and storage networks under uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, internally consumed, transported to or from other plant sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between plant sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of large-scale supply chain system.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.113-119
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• 2024

This report presents guidelines for the systematic management of packaging, storage, transportation, and traceability of source cells used for organoid research. Given the important role of source cells in organoid studies, it is important to ensure the preservation of their quality and integrity throughout transportation and distribution processes. The proposed guidelines, therefore, call for a cohesive strategy through these stages to minimize the risks of contamination, deterioration, and loss-threats that significantly compromise the safety, efficacy, and efficiency of source cells. Central to these guidelines is the quality control measures that include roles and responsibilities across the entire supply chain, with recommendations specific to packaging materials, transportation facilities, and storage management. Furthermore, the need for an integrated management system is emphasized, spanning from source cell collection to the final application. This system is crucial for maintaining the traceability and accountability of source cells, facilitating the sharing, distribution, and utilization on a global scale, and supporting to advance organoid research and development.

• International Journal of Contents
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• v.10 no.1
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• pp.62-67
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• 2014

Usually, cloud storage systems are developed based on DFS (Distributed File System) for scalability and reliability reasons. DFSs are designed to improve throughput than IO response time, and therefore, they are appropriate for batch processing jobs. Recently, cloud storage systems have been used for update intensive applications such as OLTP and so on. However, in DFSs, in-place update operations are not carefully considered. Therefore, when updates are frequent, I/O performance of DFSs are degraded significantly. DFSs with RAID techniques have been proposed to improve their performance and reliability. Their performance degradation caused by frequent update operations can be more significant. In this paper, we propose an in-place update method for DFS RAID exploiting a differential logging technique. The proposed method reduces the I/O costs, network traffic and XOR operation costs for RAID. We demonstrate the efficiency of our proposed in-place update method through various experiments.

• Journal of Radiation Industry
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• v.18 no.1
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• pp.43-52
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• 2024

Currently, there are no interim storage facilities and permanent disposal facilities in Korea, so all spent nuclear fuels are temporarily stored. However, the temporary storage facility is approaching saturation, and as a measure to this, the 2nd Basic Plan for the Management of High-Level Radioactive Waste presented an operation plan for dry interim storage facilities and dry temporary storage facilities on the NPP on-site. The dry storage can be operated in various ways, and to select the optimal dry storage method, the reduction of exposure for workers must be considered. Accordingly, it is necessary to develop a worker exposure scenario according to the dry storage method and evaluate and compare the radiological impact for each method. The purpose of this study is to develop an exposure scenario for workers transporting spent nuclear fuel by dry storage method. To this end, first, the operation procedure of the foreign commercial spent nuclear fuel dry storage system was analyzed based on the Final Safety Analysis Report (FSAR). 1) the concrete overpack-based system, 2) the metal overpack-based system, and 3) the vertical storage module-based system were selected for analysis. Factors were assumed that could affect the type of work (working distance, working hours, number of workers, etc.) during transportation work. Finally, the work type of the processes involved in transporting spent nuclear fuel by dry storage method was set, and an exposure scenario was developed accordingly. The concrete overpack method, the metal overpack method, and the vertical storage module method were classified into a total of 31, 9, and 23 processes, respectively. The work distance, work time, and number of workers for each process were set. The product of working hours and number of workers (Man-hour) was set high in the order of concrete overpack method, vertical storage module method, and metal overpack method, and short-range work (10 cm) was most often applied to the concrete overpack method. The results of this study are expected to be used as basic data for performing radiological comparisons of transport workers by dry storage method of spent nuclear fuel.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.3
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• pp.216-223
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• 2016

This paper proposes a new controller design method for a fork-type lifter (FTL) of a transportation mobile robot. The transportation robot needs to pick up a package from a stack on a storage shelf and move on by a planned path in a logistics center environment. The position of the storage shelf is recognized by reading a QR code on the floor, and using this position, the robot can move to reach the storage shelf and pick up the package. PID controllers and an adaptive controller are designed to control the velocity of two wheels and the position of the FTL. An adaptive controller for the lifter is designed to elevate up and down on a slideway to the correct height position of the package on the stack of the storage shelf. The simulation results show that the PID controllers can respond smoothly to the desired angular velocity and the adaptive controller can adapt quickly and correctly to the desired height.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.321-337
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• 1997

Rapid change in the technological environment of marine transportation and the development of the ocean shipping industry have fostered a revolution in the port system. This in turn has caused major changes in the function and use of port in Korea. Aside from this. Mokpo Port, however continues to decline, because the existing port facilities and related subsystem are already obsolete with no chance of regaining operational effectiveness and treatment for proper implementation. Although a few studies have been done on the Mokpo Port, has not been found, any reseach for the analytical approach to the transportation system of it. This paper aims to make an extensive analysis of the physical distribution system in Mokpo Port focusing on the coordination of subsystems such as navigational aids system, quay handling and transfer system, storage system and inland transport system. The base of introduced simulation tool here is the queueing theory. The overall findings are as follows; 1. Among those vessels called at Mokpo Port in 1994, the average size of oceangoing vessels is 4,922.1 G/T, and the domestic is 317.8 G/T. The average arrival interval and service time of the domestic vessels are 6.0 hours and 24.1 hours respectively marking the berth occupation rate over 100%. Those for oceangoing vessels are 34.5 hours, 120.0 hours and 37.2%. In order to maintainin the berth occupation rate to 70% the capacity considering the 1994 of domestic piers must be extended to 145% and oceangoing vessels must be increased to 165% year called. 2. The capacity of approaching channel is enough to handle the total traffic volume. 3. Tugs are sufficiently being provided to handle all ships requiring their services 4. The capacity of storage and inland transportation systems are sufficient to handle the throughput and the yard stroage utilization rate of No.1 $\cdots$ No.5 is 4.5% and No.6 1S 30% of 1993's. 5. The utilization rate of LLc(Level Looping Crane) and PNT(PNeumaTic) are 2.7% and 18.8%, respectively. Practical solution and proposal for improvement of Transportation System in Mokpo Port are as follows; 1. To avoid the congestion in domestic pier introduction of a new port operation system is necessary allowing the domestic vessel to use the oceangoing pier. 2. To establish the port management information system to improve the efficiency of port operation. 3. To build a new storage system for high valued cargos including modernization of the present storage and handling system. 4. To insure the safety of navigation in approaching channel, The Vessel Traffic System including separation scheme is introduced. 5. To interest enormously on public relation to ship owner's association, shippers and consignees by showing that they can save cost and ship turnaround time in order to promote the call to Mokpo Port. At last, to be strategically change the function of Mokpo Port to the Leisure, Fishing & Ferry as well as Maritime port.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1159-1163
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• 2014

This paper have been dealt with the analysis for energy efficiency improvement effect of unity storage capacity as a part of the energy storage application study to improve energy efficiency in the electric railway systems. Especially, in order to estimate the amount of energy saving according to the variation of power capacity of each storage, the current limit module was mounted on an existing DC electric railway loadflow program which is based on the analysis model for railway system and storages, and combined optimization algorithm to determine optimal voltage boundary.

• Solar Energy
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• v.18 no.3
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• pp.169-175
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• 1998

Metal hydrides can be used for the purpose of heat storage and transportation from the industrial complex which own recoverable waste heats to the neighboring cities by the medium of hydrogen. The properties of metal hydrides, some problems of heat transportation using metal hydrides, and the example of heat transportation system were discussed.