• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.40-45
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• 2003

To evaluate the smoke control systems, the large eddy simulation turbulence model based Fire Dynamics Simulate was applied to a 2m $\times$ 2m $\times$ 2.4m room with an opening. The smoke removal rate was investigated for three different smoke control systems: ventilation, extraction and pressurization. When the opening was closed, the smoke removal rates of the smoke control systems were almost the same as expected. The pressurization system showed a lower smoke removal rate compared with the other two smoke control systems for the room with the opening, and hence the pressurization system might not be efficient for a place with large openings. It was shown that the lower extraction flowrate is, the longer time the ventilation system requires to remove smoke. From these results, the ventilation system is recommended for subway stations where several large openings exist.

• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.167-176
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• 2008

Vulnerability assessment of power systems is important so as to determine their ability to continue to provide service in case of any unforeseen catastrophic contingency such as power system component failures, communication system failures, human operator error, and natural calamity. An approach towards the development of on-line power system vulnerability assessment is by means of using an artificial neural network(ANN), which is being used successfully in many areas of power systems because of its ability to handle the fusion of multiple sources of data and information. An important consideration when applying ANN in power system vulnerability assessment is the proper selection and dimension reduction of training features. This paper aims to investigate the effect of using various feature extraction methods on the performance of ANN as well as to evaluate and compare the efficiency of the proposed feature extraction method named as neural network weight extraction. For assessing vulnerability of power systems, a vulnerability index based on power system loss is used and considered as the ANN output. To illustrate the effectiveness of ANN considering various feature extraction methods for vulnerability assessment on a large sized power system, it is verified on the IEEE 300-bus test system.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.527-534
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• 2021

The demand for sustainable extraction of bioactive compounds from food matrices has been increasing. Water extraction of anthocyanins in aronia was investigated using conventional and ultrasonic-assisted methods. The optimum extraction conditions for the conventional method included a sample-to-water ratio of 1:40 g/mL, extraction temperature 71℃, and extraction time of 39 min. The optimized conditions for ultrasonic-assisted extraction were a sample-to-water ratio of 1:40 g/mL, extraction temperature 80℃, extraction time of 20 min, and an amplitude of 87.2 ㎛. The anthocyanin contents of the two extracts were 155.32 and 158.02 mg/100 g fresh weight, respectively. The major anthocyanins were cyanidin 3-galactoside (65% of the total) and cyanidin 3-arabinoside (30% of the total). The contents of individual anthocyanins and phenolic acids were not significantly different between the two optimized extracts.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1175-1182
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• 2004

Installations of vertical boreholes for the ground source heat pump system are expensive to install. One way to reduce the initial cost is to increase the specific heat extraction rate of borehole system. However, as the specific heat extraction rate increases the temperature of borehole fluid decreases with the resultant lower Coefficient Of Performance in Heating(COPH) of heat pump system. The purpose of this study is to provide the basic informations about the performance of heat pump system with the specific heat extraction rate and soil thermal properties such as thermal conductivity and temperature. It is shown that the specific heat extraction rate is the most important parameter for the ground source heat pump system. To obtain the reasonable COPH value (COPH > 3) the heat extraction rate should be about 25 W/m or less. Accurate measurements of soil thermal properties are also very important to design the system properly. The effects of borehole thermal resistances are also examined in this study.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.67
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• pp.49-60
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• 2001

Data warehouse(DW) manages all information in a Enterprise and also offers the specific information to users. However, it might be difficult to develope an effective DW system due to varieties in computing facilities, data base, and operating systems. The heterogeneous system environments make it harder to extract data and to provide proper information to usesr in real time. Also commonly occurred is data inconsistency of non-integrated legacy system, which requires an effective and efficient data extraction flow control as well as data cleansing. We design the integrated automatic ETT(Extraction Transformation Transportation) system to control data extraction flow and suggest implementation methodology. Detail analysis and design are given to specify the proposed ETT approach with a real implementation.

• ETRI Journal
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• v.25 no.2
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• pp.101-108
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• 2003

This paper proposes an improved vascular pattern extraction algorithm for person verification applications. The proposed direction-based vascular pattern extraction (DBVPE) algorithm is based on the directional information of vascular patterns. It applies two different filters to the input images: row vascular pattern extraction filter (RVPEF) for effective extraction of the abscissa vascular patterns and column vascular pattern extraction filter (CVPEF) for effective extraction of the ordinate vascular patterns. We use the combined output of both filters to obtain the final hand vascular patterns. Unlike the conventional hand vascular pattern extraction algorithm, the directional extraction approach prevents loss of the vascular pattern connectivity. To validate the DBVPE algorithm, we used a prototype system with a DSP processor. The prototype system shows approximately a three-times better false acceptance rate (FAR) than the conventional single filter algorithm.

• Journal of Industrial Convergence
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• v.13 no.2
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• pp.45-54
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• 2015

This Study aims to analyze the factors for the success of commercialization of the facial extraction and recognition image security information system of the domestic companies in Korea. As the results of the analysis, the internal factors for the success of commercialization of the facial extraction and recognition image security information system of the company were found to include (1) Holding of technology for close range facial recognition, (2) Holding of several facial recognition related patents, (3) Preference for the facial recognition security system over the fingerprint recognition and (4) strong volition of the CEO of the corresponding company. On the other hand, the external environmental factors for the success were found to include (1) Extensiveness of the market, (2) Rapid growth of the global facial recognition market, (3) Increased demand for the image security system, (4) Competition in securing of the engine for facial extraction and recognition and (5) Selection by the government as one of the 100 major strategic products.

• Journal of Biomedical Engineering Research
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• v.30 no.4
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• pp.311-317
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• 2009

An automatic control system is proposed and implemented for a miniaturized DNA extraction system using magnetic bead. A host-local system is employed for the accommodation of the graphical user interface and the basic control function. The functional partitioning into the local and the host system is discussed. The control functions are classified and formalized for the flexible control scenario, which is the input of the proposed system. As the proposed scenario is consists of the sequence of the user-centric actions, the user goal can be easily programmed and modified. The DNA extraction performance of the implemented system was compared with the existing silica-membrane-based method, resulting in the comparable concentration and purity of the extracted DNA. The proposed system is currently being utilized for the development of the DNA extraction system only changing scenario, without any alteration of the system.

• Solar Energy
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• v.18 no.3
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• pp.71-80
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• 1998

In thermal energy storage system, energy collected from many types of heat source is stored in a storage tank and then supply to load for demand. Lately, practical use of thermal energy storage system and attention to essential use of energy have been increased. From this point of view, especially, a study about the energy extraction process from a storage tank is necessary. So in this study, useful rate of hot water and hot water extraction efficiency was analysed respect to dynamic and geometric parameters dominating the hot water extraction process.

• Analytical Science and Technology
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• v.13 no.4
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• pp.511-519
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• 2000

Water in the supercritical state ($T{\geq}374^{\circ}C$, $p{\geq}221$ atm) is a good solvent for nonorganic pollutants, but it is extremely corrosive. Subcritical Water Extraction (SWE) is a very fast and an efficient method to extract nonpolar environmental pollutants adsorbed on the sediments and soils. Many nonpolar organic compounds are sufficiently soluble to be extracted to the water under subcritical conditions. Complete extraction of PCBs from the sediments and soils takes only a few minutes by applying SWE with the subcritical water at 50 atm and at $260^{\circ}C$.