• Fire Science and Engineering
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• v.34 no.3
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• pp.43-48
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• 2020

The purpose of this study is to develop an earth leakage alarm circuit breaker, equipped with a leakage alarming function (JER-E2S, ETECKOREA Co., Korea), and to analyze its characteristics. The developed mechanism is exclusively used for single-phase and 220 V circuits, with a rated current of 32 A, 20 A, 20 A (for restrooms), 16 A, etc. It satisfies all characteristics of existing earth leakage circuit breakers (ELB). If a fire current, which is a resistive leakage current (Igr), flows through an electric line, the device detects the leakage current in real time and warns against the leakage through a blinking LED lamp. Since the developed device displays a tolerance to a capacitative leakage current (Igc) that inevitably occurs in LED lamps, communication devices, etc., it ensures a stable power supply. In addition, the earth leakage alarm circuit breaker protects against power failure due to a momentary ground fault. Therefore, it can supply power without the risk of the circuit breaker malfunctioning due to a momentary ground fault caused by water droplets, leaves, etc. Moreover, with a standby power of less than 0.1 W, the developed earth leakage alarm circuit breaker exhibits a power saving performance that is 3~8 times greater than that of other ELBs. Installation of approximately 10 earth leakage alarm circuit breakers in one apartment household, with an area of 120 ㎡, can save 2~5 kWh per month. Therefore, the developed earth leakage alarm breaker not only satisfies the characteristics of existing earth leakage breakers, but also exhibits outstanding power supply quality since it has the functions of electric fire prevention and malfunction prevention. Therefore, this device can innovatively contribute to electric fire prevention.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.704-710
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• 2012

This study was designed to investigate the effect of pulsed electric fields on the drying of ginseng and extraction of dried ginseng to reduce energy-consumption. Fresh ginseng was treated in a PEF system of 1 and 2 kV/cm electric field strength, 25 and 200 Hz of frequency, $30{\mu}s$ of pulse width and pulse number of 175. The samples were subsequently dried for 26 h at $55{\pm}1^{\circ}C$, and the characteristic of hot-water extraction on dried ginseng was investigated. The ginseng pretreated with an intensity of 2 kV/cm (200 Hz, n=175) resulted in a reduction of approximately 38% for drying time. The influence of PEF treatment on the water extraction of dried ginseng at $95{\pm}1^{\circ}C$ was also investigated. The application of an electric field intensity of 2 kV/cm (25 and 200 Hz, n=175) increased soluble solid content, significantly reducing sugar content and free sugar content of the extract compared to non-PEF-treated samples.

• Journal of Life Science
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• v.21 no.1
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• pp.56-61
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• 2011

This study was performed to investigate effective extract conditions in fronds of the Ostrich fern (Matteuccia struthiopteris) to increase antioxidant compound contents and antioxidant capacity. Powder (1 g) of lyophilizated fronds were mixed with 3 kinds of solvents (MeOH, 80% EtOH and water). Extractions were carried out using not only immersion (room temp.), heating ($60^{\circ}C$) and stirring (200rpm) for 6 hr, but also through sonication in a 42 kHz ultrasonic bath for 15, 30 and 45 min. Extracts were filtrated and measured for contents of soluble solids (SS), total polyphenols (TP; tannic acid as a standard) and total flavonoids (TF; Naringin as a standard). Antioxidant activity was expressed as $RC_{50}$ for DPPH and ABTS radical scavenging. SS (0.317 $g{\cdot}g^{-1}$ db), TP (70.90 $mg{\cdot}g^{-1}$ db) and TF (41.53 $mg{\cdot}g^{-1}$ db) contents reached their highest levels when 30 minute sonication extraction with 80% EtOH was performed, and the highest DPPH and ABTS scavenging activity was observed in the same extraction conditions ($RC_{50}$=0.14 $mg{\cdot}ml^{-1}$ and 0.09 $mg{\cdot}ml^{-1}$, respectively). From the present investigation, it can be concluded that fronds of the ostrich fern can be used as a natural material for antioxidants, and sonication for 15-30 min with 80% EtOH is an ideal extraction method for increasing their antioxidant effects and saving extraction time.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.101-111
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• 2015

The modular construction method has been getting more attention followed by global eco-friendly trend as the domestic construction industry has focused more on remodeling and extension work. The modular construction method is an industrialized construction system which is not likely as the existing construction method it manufactures more than 70% modules at the factory then assembling can be completed in a short amount of time on site. The modular construction method has various strengths; shortening of construction period by on-site work decrease, weight pressure reduction by usage of light steel frames and cost saving by repetitive manufacturing. However, it is currently not expanded due to the existing commercialized construction method. Therefore, this research is in order to help the related authorities make decisions to select the construction method and motivate expansion of modular construction method which can be utilized effectively in the extension works. The intention of this research is to stress differentiation from other construction methods in construction period, construction expenses, labor and forces by comparing and analyzing actual cases, to inform competitiveness of modular construction method by concrete effect analysis and to support adoption of the modular construction method into the domestic industry.

• Journal of Information Technology and Architecture
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• v.10 no.4
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• pp.435-449
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• 2013

The performance of Enterprise Architecture (EA) in the Korea's public IT domain produces mixed results and responses. On the one hand, EA earns positive remarks and enthusiasm as a central government-wide IT governance framework with its significant IT budget saving records. At the same time, however, the response to EA at the department and agency level is tainted with disappointment, fatigue, and reluctance. This essay suggests that this is perhaps caused by the sterile lackluster concept of EA Business Architecture employed in the current EA practice of the enterprise. The possibility for liberating and reviving the concept of EA Business Architecture is explored. Various conceptual axes and branches of EA Business Architecture are identified based upon extensive EA field experience and observations, and discussions are made on how the concept of EA Business Architecture can be expanded and amplified on those conceptual axes and branched. The resulting EA Business Architecture conceptualization is consolidated into an illustrative typology for EA Business Architecture. In the end the theoretical and practical implications of the research are discussed along with its contribution and limitation.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.2
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• pp.53-60
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• 2016

In this paper, we introduce the implementation and test results of a new method of correlated result storage to achieve the full performance of the Daejeon hardware correlator. Recently, the observation of 8 Gbps speed, which is the maximum observational standard of KVN(Korean VLBI Network), has been performed. The correlation processing using the Daejeon hardware correlator is also required. Therefore, a new correlation result storage introduction has become necessary. The maximum correlation result output speed of the Daejeon hardware correlator is 1.4 GB/sec per 25.6 ms integration time. The conventional correlation result storage system can not cope with the maximum correlation output speed of the Daejeon hardware correlator, and the output speed is limited to 1/4. That is, among the four input ports of the Daejeon hardware correlator, the three inputs are limited to correspond to the observation rate of 1 Gbps. This new storage system uses the Gluster file system among many of the latest technologies used in storage systems. In tests that meet the maximum output rate of 1.4 GB/sec for the Daejeon hardware correlator, 350 MB/sec for each of the four optical outputs, resulting in 1.4 GB/sec in total.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.592-603
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• 2019

This study is about the implementation of low energy sewage management technology through effective control of blower which consumes the most energy in sewage treatment. In calculating the amount of oxygen required for microorganisms, unlike the existing method using the operating index in the bioreactor or TMS data in the discharge port, the CODcr and NH₄⁺-N concentration changes in sewage flowing into the sewage treatment plant were detected in advance before entering the bioreactor and the amount of air was controlled based on this. The pre-sensing was found to have a high correlation compared with conventional products. As a result of blower control, it was possible to save about 9.9% energy more than the manual control. Consequently, this study suggested the possibility of blower's real-time control combined with pre-sensing technology. Also, it is expected that the low energy sewage treatment can be applied to sewage treatment facilities dependent on operation by manpower, and it will contribute to the reduction of greenhouse gas emissions.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.108-121
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• 2012

As Scalable Video Coding (SVC) is a video compression standard extended from H.264/AVC, it is a way to provide scalability in terms of temporal, spatial and quality. Although the compression efficiency of SVC is increased due to the scalability in many aspect, it is essential to reduce the complexity in order to efficiently use because the complexity is relatively increased. To reduce the complexity of SVC in the paper, we propose fast mode decision algorithm to reduce the complexity of encoding process using direction information of B-picture by efficiently performing inter-layer prediction. The proposed algorithm is a fast mode decision algorithm that makes different from detection mode number of forward and backward, bi-direction in the way using best mode of base-layer up-sampled after simply SKIP mode detection using the direction information of best mode of base-layer up-sampled. The experimental results show that the proposed algorithm approach can achieve the maximum computational time saving about 53% with almost no loss of rate distortion (RD) performance in the enhancement layer.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.179-190
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• 2012

In Distributed Video Coding(DVC), a low complexity encoder can be realized by shifting complex processes of encoder such as motion estimation to decoder. Since not only motion estimation/compensation processes but also channel decoding process needs to be performed at DVC decoder, the complexity of a decoder is significantly increased in consequence. Therefore, various fast channel decoding methods are proposed for the most computationally complex part, which is the channel decoding process in DVC decoding. As the channel decoding process becomes faster using various methods, however, the complexity of the other processes are relatively highlighted. For instance, the complexity of side information generation process in the DVC decoder is relatively increased. In this paper, therefore, a fast method for the DVC decoding is proposed by using adaptive search range method in side information generation process. Experimental results show that the proposed method achieves time saving of about 63% in side information generation process, while its rate distortion performance is degraded only by about 0.17% in BDBR.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.342-352
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• 2016

Purpose: This study conducted an Importance-Performance Analysis (IPA) of selective attributes of Home Meal Replacement (HMR) as well as it examined the consumers' needs and willingness to buy HMR products to explore the need for developing more HMR products. Methods: This study was conducted among domestic consumers living in Seoul and its metropolitan areas, in the age range from the 20s to the 50s, and who had experience in purchasing HMR products. From the 490 surveys retrieved, 472 (96.3%) valid surveys were analyzed. Results: The analysis of the frequency of consuming HMR products showed the following results: 247 respondents answered '1-3 times a month' (52.3%); 167 respondents stated '1-2 times a week' (35.3%). With respect to the reason of purchase, 'simplicity of the recipe' was the most common, accounting for 188 respondents (39.8%), followed by 'time efficiency' accounting for 172 respondents (36.4%). Analysis of the demand for bibimbap (mixed rice) HMR products showed that 'chicken bibimbap' had the highest preference with 5.32 points, followed by 'bulgogi bibimbap' (5.08 points), and 'kimchi bibimbap' (4.96 points). In the case of HMR products that need to undergo further development, 'low-sodium products' received the highest points of 5.41 points, followed by 'small packaged products' (5.05 points), and 'functional products' (4.98 points). The factor analysis of the 13 selective attributes showed that they can be divided into 3 factors. The IPA analysis of the selective attributes of HMRs showed 'hygiene', 'taste', 'easy to go packaging', 'convenience in intake', and 'accessibility' in the 1st quadrant. In the 2nd quadrant, 'price' and 'freshness' were shown as the factors. In the 3rd quadrant, 'easy to serve', 'familiar food menu', and 'consistent menu' were shown as the leading factors, and in the 4th quadrant, 'saving labor' was the only factor. Conclusion: Based on these results, the research concludes that with respect to developing HMR products, there is a high demand for low sodium, low calorie, small packaged products; thus, showing the need to develop various HMR products for customer satisfaction. Furthermore, it shows that there is a need to consider developing HMR products that can maintain freshness at an affordable price.