• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.740-743
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• 2012

The initial role of the operating system acts as an intermediary between the computer and the user, and, hardware and process management, and the convenience of your computer system is to use. Of these operating systems as well as servers and personal computers, smartphones and tablet mounted on mobile devices such as mobile operating system was born. Mobile Operating System has been expanded a TV or Car Area that built into a simple embedded operating system, is emergence of a variety of devices, cloud services, combined with the desire of users due to the high built-in simple embedded operating system that was working on a TV or a car is expanding to the area. The reason for the emergence of a variety of devices, cloud services, combined with the desire of users is high. In this paper, the mobile operating system, N-Screen, Smart TV to find out about and through the analysis of the major smart TV, the future Find out about trends in the mobile operating system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.456-461
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• 2010

This study compares the criteria of earth leakage breakers (ELB) and analyzes the characteristics of an Igc-free ELB operated by an active component which is not misoperated by capacitive current. Even for the same ELB, the earth leakage current flowing through the human body is estimated to be differ greatly depending on the power source, voltage, location and status of contact, contact time duration, etc. Earth leakage breakers are classified based on the rated voltage, rated sensing current, rated operating time etc. Mounting and demounting of the existing equipment can be performed easily since an $I_{gc}$-free ELB is manufactured with the same structure as a conventional ELB. The rated operating current of a conventional and an $I_{gc}$-free ELB is 30mA, the sensing current is 25mA and the rated non-operating current is 15mA. In the analysis of non-operating current characteristics, the rated non-operating current of 15mA was satisfied up to a 20mA charging current in the conventional ELB, but does not satisfy the rated non-operating current as it operates when the resistive leakage current is lower than 15mA for a charging current exceeding 20mA. Also, the ELB is misoperated without a resistive leakage current when the charging current exceeded 25mA. However, the newly developed $I_{gc}$-free ELB satisfied the rated non-operating current even when the charging current was 60mA. Also, in comparison to the interrupting characteristics, it was confirmed that the charging current satisfying the rated non-operating current of the $I_{gc}$-free ELB was three times higher than that of the conventional ELB.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.4
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• pp.3600-3610
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• 1974

Experimental work of batch-type dryer was conducted to develop its optimurm operating conditions by analyzing the major factors which affect the drying performance. A laboratory batch-type dryer was constructed and tested for various levels of heated-air rates, and depths of grain deposit. Tong-il rice variety having the initial moisture content of approximaely 23 per cent in wet basis was used for the experiment. The criteria selected for establishing the optimum operating condition were the drying performance rate, the thermal efficiency, and the operational cost of the dryer. The results of the study are summarized as follows: 1. The performance rate of dryer for a specific operating condition was defined as total amount of material dried per hour when the moisture content of grains in the upperlayer reaches to 16 per cent in wet basis. The optimum operating conditions as viewed in the rate of drying performance could be justified by functional realtionship between the depth of grain deposit and air flow rate. In other words, there was a definite depth of grain deposit for a given air-rate which make the dryer performance maximum. The optimum grain depth for the batch-type dryer with 3.3㎡ loading area and with the attached axial fan was about 35cm. 2. The thermal efficiency for the dryer was evaluated by the ratio of the latent heat required to evaporate the grain moisture to the heat input required to raise the ambient air-temperature to 40 degree centigrade. The optimum operating condition as viewed in term of thermal efficiency analyzed was that grater depth and lower air flow-rate may be desirable. This condition is contracted with the optimum condition as viewed by the dryer performance rate. 3. The annual operating cost of batch-type dryer was analyzed for different annual hour of use and for different operation condition. The optimum condition as viewed in terms of operating cost was almost identical to one as viewed in terms of dryer performance rate. Therefore, the most economical use of batch-type dryer for the same annual operating hours can be obtained when the dryer operated in the condition of maximum dryer performance rate. Increasing the annual operating hour may be desirable to cut down the dryer operation cost, since the annual hour of dryer use is much sensitive to the operating cost than any peractical conditions of dryer operation. 4. The most desirable operational condition as justified by combining all the criteria, dryer performance rate, thermal efficiency and annual operating cost, could be concluded to operate the dryer in the condition of maximum performance rate. The condition in general is identical to the lowest operation cost for a given annual operating hour.

• Journal of the Korean Chemical Society
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• v.55 no.5
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• pp.824-829
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• 2011

In Fischer-Tropsch Synthesis, because of few reactants ($H_2$, CO), scarce operating parameters affected on efficiency especially the selectivity of products. In this research, effect of operating parameters on the selectivity of Co-Mn-$TiO_2$ Fischer-Tropsch synthesis catalyst were studied by design of experimental procedure and Taguchi method. According to this research, interactions between operating factors have a crucial effect on light products selectivity. Among these interactions, (temperature${\times}$feed ratio) has the main influence on light hydrocarbons selectivity. It was concluded that temperature and feed ratio ($H_2$/CO) were the most integral operating parameters for much greater selectivity of light hydrocarbons.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.5
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• pp.287-293
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• 2003

The deregulation and structural reform of power markets have started from the early 90s, which has brought about new studies on the new environment. Regardless the market structure, however, power systems need to be operated and planned in a stable and reliable manner. Therefore, decisions on proper amount of operating reserves and their reliable operations are very important. Up to now, the decision processes of operating reserves depend mainly on experiences of operators in Korea. When Korean power market comes under private management, operating reserves would influence power rate as well as power Quality, Therefore, it is time to prepare reasonable operating reserve standards in a systematic way for the new environment. This study suggests the proper operating reserve standards considering rules of the power market in Korea. To verify the adequacy of the proposed standards, stability and frequency characteristics of the Korean power system are analyzed as well.

• Journal of the Korean Society of Costume
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• v.54 no.3
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• pp.65-71
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• 2004

Surgical operating gowns are worn by doctors and nurses in operating theater to address dual function of preventing transfer microorganisms like bacteria and body fluids from the operating staffs to patients. and also from patients to staff. They must allow necessary mobility without rubbing and must resist tearing. These gown must be designed to fit a diversity of body shapes and sizes with a limited range of sizes as hospitals will stock limited quantities. Also they must proper in various operating situations. In order to suggest improving design features of surgical gowns, it has been done to analyze current situation of medical uniform manufacturing and wearing. Surgical gown were made with plain fabric of cotton 100% and had a little size system without sexual division. Many doctors were unsatisfied with surgical gown size and wearing comfort. Surgical operating gowns need continuos research for new material and design as surgical situation, and new sizing system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.694-699
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• 2009

Combined cycle plants which feature distinct advantages for power generation such as fast response, high efficiency, environmental friendliness, fuel flexiblity represent the majority of new generating plant installations across the globe. Combined cycle plants have different operating modes where the operating parameters can differ greatly depending which mode is operating at the time. This paper addresses the bidding strategy model of combined cycle plants in a competitive electricity market by using a characteristic of multiple operating modes of combined cycle plants. Simulation results of case studies show that an operating mode among multiple ones is selected strategically in generation bidding for more profit of generation company.

• Journal of Korean Society of Transportation
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• v.11 no.2
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• pp.45-62
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• 1993

The major objective of this study is to analyze the differences between operating costs of teleconferencing and alternative transportation modes for the conference in major compaines. Alternative transportation modes include road, rail, and air transportation mode. A case study is conducted using the data gathered for Pohang Steel Coperations. The main results are: (1) the operating cost of the teleconferencing is cheaper than operating cost of transportation modes when the number of teleconferencing are over 12 frequencs, and the number of person are over 15. Results reveal that teleconferencing turns out to be effective means of conference. (2) the amount of differences of operating costs on teleconsferencing and transportation modes gets higher according to the time elapsed. In particular, when teleconferencing cost is compared to operating cost of road transportation, it is found that the cost saving of 2.75 billion won in year 2001 can be realized.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.63-70
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• 2010

Based on the known results of the expected busy periods for the triadic Min (N, T, D) and Max (N, T, D) operating policies applied to a controllable M/G/1 queueing model, a relation between them is constructed. Such relation is represented in terms of the expected busy periods for the simple N, T and D, and the dyadic Min (N, T), Min (T, D) and Min (N, D) operating policies. Hence, if any system characteristics for one of the two triadic operating policies are known, unknown corresponding system characteristics for the other triadic operating policy could be obtained easily from the constructed relation.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.140-144
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• 2002

A free piston and free displacer (FPFD) Stirling cryocooler has been widely used for the cooling infrared and cryo-sensor. The thermodynamic performance of the free piston and free displacer type (FPFD) Stirling cryocooler is highly dependent on the operating frequency of the linear compressor and the natural frequency of the displacer. In this study, to find optimal relation between operating and natural frequency of the displacer the dynamic characteristics of the displacer in the expansion space of the Stirling cooler was investigated by experiment. The experimental results show that the Stifling cryocooler has maximum cooling capacity at the operating frequency of about 0.8 times of the natural frequency of displacer. Therefore the operating frequency of the Stirring cryocooler should be determined by natural frequency of the linear compressor and displacer.