• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.73-80
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• 2016

The preliminary test for the dual mode plasma torch system was carried out to explore the operation properties in advance. The dual mode plasma torch system that is able to operate in transferred, non-transferred, or dual mode is very adequate for melting the mixed wastes including nonconductive materials such as concrete, asbestos, etc. since it exploits both the high efficiency of heat transfer to the melt in transferred mode and stable operation in non-transferred mode. Also, system operation including restarting is reliable and very easy. A stationary melter with a refractory structure was designed and manufactured considering the melting behavior of slags to minimize the refractory erosion. The power supply for the dual mode plasma torch system built with high power insulated gate bipolar transistor (IGBT) modules has functions for both current control and voltage control and is sufficient to suppress the harmonics during the operation of the plasma torch. The power supply provides two different voltages for transferred operation and non-transferred. It is confirmed that the operation voltage in transferred is always higher than non-transferred. The dual mode plasma torch system was successfully developed and is under operation for a melting experiment to optimize operation data.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.35-41
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• 2000

In this paper, the multiplicative algorithm of two polynomals over finite field GF(2$^{m}$ ) is presented. The proposed algorithm permits an efficient realization of the parallel multiplication using iterative arrays. At the same time, it permits high-speed operation. This multiplier is consisted of three operation unit: multiplicative operation unit, the modular operation unit, the primitive irreducible operation unit. The multiplicative operation unit is composed of AND gate, X-OR gate and multiplexer. The modular operation unit is constructed by AND gate, X-OR gate. Also, an efficient pipeline form of the proposed multiplication scheme is introduced. All multipliers obtained have low circuit complexity permitting high-speed operation and interconnection of the cells are regular, well-suited for VLSI realization.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.5
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• pp.269-277
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• 2018

NAND flash memory has widely been used because of non-volatility, low power consumption and fast access time. However, it suffers from inability to provide update-in-place and the erase cycle is limited. The unit of read/write operation is a page and the unit of erase operation is a block. Moreover erase operation is slower than other operations. We proposed the Adaptive Garbage Collection (called "AGC") policy which focuses on not only reducing garbage collection process time for real-time guarantee but also wear-leveling for a flash memory lifetime. The AGC performs better than Cost-benefit policy and Greedy policy. But the AGC does not consider the operation characteristics. So we proposed the Advanced Adaptive Garbage Collection (called "A-AGC") policy which considers the page write operation count and block erase operation count. The A-AGC reduces the write operations by considering the data update frequency and update data size. Also, it reduces the erase operations by considering the file fragmentation. We implemented the A-AGC policy and measured the performance compared with the AGC policy. Simulation results show that the A-AGC policy performs better than AGC, specially for append operation.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.6
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• pp.910-920
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• 1990

This paper presents a method of constructing an Arithmetic Operation Unit Systems (A.O.U.S.) over Galois Field GF(2**m) for the purpose of the four arithmetical operation(addition, subtraction, multiplication and division between two elements in GF(2**mm). The proposed A.O.U.S. is constructed by following procedure. First of all, we obtained each four arithmetical operation algorithms for performing the four arithmetical operations using by mathematical properties over GF(2**m). Next, for the purpose of realizing the four arithmetical unit module (adder module, subtracter module, multiplier module and divider module), we constructed basic cells using the four arithmetical operation algorithms. Then, we realized the four Arithmetical Operation Unit Modules(A.O.U.M.) using basic cells and we constructd distributor modules for the purpose of merging A.O.U.M. with distributor modules. Finally, we constructed the A.O.U.S. over GF(2**m) by synthesizing A.O.U.M. with distributor modules. We prospect that we are able to construct an Arithmetic & Logical Operation Unit Systems (A.L.O.U.S.) if we will merge the proposed A.O.U.S. in this paper with Logical Operation Unit Systems (L.O.U.S.).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.44-51
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• 2009

A bonded warehouse is the warehouse located in bonded area. It functions not only as a general warehouse but also as a place for managing the work related to import and export bonded goods. As a general warehouse, it uses the rack system to store the goods and the folk lift truck to move the unitized goods. The operation of the storing system closely related to the efficiency of space uses in a warehouse and vehicle working. Thus, vehicle performance measured in distance units in the ware-house could be used as one of the key performance measure in warehouse system. This paper focuses on the operation efficiency of the bonded warehouse which uses rack system for the storing and the folk lift truck for moving goods. The method of load allocation for balancing the rack uses and vehicle operation for maximizing efficiency are the specific concerns in this paper. The simulation study is conducted to find a policy for efficient vehicle operation based on balanced rack utilization, and the favorable result for the system operation would lead the usable proposal in vehicle operation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.1
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• pp.80-90
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• 2008

This study was carried out to investigate the correlation of urinary NMF concentration in workers exposed to DMF and concentration of DMF in the workplace. Samples were collected in workers exposed to high dose solvent in the synthetic leather factory by using silicagel tubes for 5-15 minutes, and were analyzed by GC. Geometric mean concentrations of DMF in the workplaces were 4.67 ppm in normal operation and 63.95 ppm in high exposure operation. The concentration of case uppers and machine cleaning process were more than 100 ppm in short time. The correlation of urinary NMF in workers and DMF in workplace was statistically significant in normal operation and high exposure operation. Correlation coefficient are 0.215(p<0.05) and 0.263(p<0.05). The result implied that STEL of DMF should be established in normal operation processes as well as high exposure operation processes.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1335-1341
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• 2015

The utilization of electric vehicles has been suggested to support the frequency regulation of power system. Assuming that an intermediate aggregator exists, this study suggests a decentralized vehicle-to-grid operation scheme in which each vehicle-to-grid aggregator can behave independently of the power system operator. To implement this type of decentralized operation, this study adopts a price-based operation that has been proposed by many researches as an alternative operation scheme for the power system. In this environment, each vehicle-to-grid aggregator can determine its participation in vehicle-to-grid service in consideration of its residual energy of aggregated system and real-time market price. Consequently, the main purpose of this study is to verify whether or not the vehicle-to-grid power can effectively support the current frequency regulation function within the price-based operation scheme. Specifically, a frequency regulation method is proposed based on the real-time price signal, and a feedback controller for battery management is designed for decentralized vehicle-to-grid operation.

• Journal of Korean Academy of Nursing Administration
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• v.14 no.1
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• pp.72-84
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• 2008

Purpose: The purpose of this study was to identify nurses' duties and tasks for job analysis of the nurses in the operating room. Methods: This study was descriptive investigation research using the 3-point likert scale questionnaires and the level of importance, difficulty and the frequency of each duty and task were analyzed. Data were collected by 422 OR nurses from 57 hospitals. Results: Job of OR nurses included 13 duties and 105 tasks. The 13 duties were 'management of operative patient' 'assistive work for operation' 'supportive work for operation' 'infection control in OR' 'management of equipments and instruments for operation' 'administrating medicine for operation' 'supplies management for operation' 'safety management for operation' 'environmental management for operating room' 'administrative work for operation' 'education for operating room personnel' 'development of operation procedure books' and 'elf development of OR personnel' Conclusion: This study identified duties and tasks performed by OR nurses. Based on these results, the importance, frequency, and difficulty in this study will provide research evidence for developing training programs for OR nurses.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.2
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• pp.15-20
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• 2016

Background: The purpose of this study was to compared of scapular position between operation side and non-operation side to the rotator cuff surgery. Methods: This study was carried out with a total 34 patients: male (n=14), female (n=20). Shoulder range of motion (ROM), the quadruple visual analogue scale (QVAS), the shoulder pain and disability index (SPADI), and the scapular index (SI) were used to assess shoulder posture and function. SI was the resting position of the scapular was determined by measuring the distance from the mid-point of the sternal notch (SN) to the medial aspect of the coracoid process (CP) and the horizontal distance from the posterolateral angle of the acromion (PLA) to the thoracic spine (TS) with a soft tape measure. The SI was calculated using the equation: [(SN to CP/PLA to TS) ${\times}$ 100]. Results: There were no significant difference in ROM, QVAS to rotator repair patients according to SI (p>.05). There were significant differences in SI between the operation side and the non-operation side (p<.01). Conclusions: Scapular position was operation side more internal rotation, protraction, abduction than non-operation side. Therefore, health professionals managing for rotator cuff tear repair patients should consider scapular position.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.341-349
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• 2004

A parallel operation of Uninterruptible Power Supply(UPS) systems is used to increase power capacity of the system or to secure higher reliability at critical loads. In the conventional parallel operation, the load-sharing control to maintain the current balance is the most important, since the load-sharing is very sensitive to discord between components of each module, amplitude/phase difference, line impedance, output LC filter, and so on. To solve these problems various control algorithms are researching. However, these methods cannot apply to the different ratings of UPS. In the case, master and slave control algorithm for parallel operation is adequate. However, if the UPS ratings are different, the value of passive filters L, C is different, and it affects the sharing of current. This paper presents general problems of conventional parallel operation systems, and control strategy for parallel operation with different ratings. The validity of the proposed control strategy is investigated through simulation and experiment in the parallel operation system with two 3-phase UPS systems.