• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.4
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• pp.231-236
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• 2011

When the Fukushima nuclear power plant accident occurred in March of 2011, a hydrogen explosion in the reactor building at the 4th unit of Fukushima plants led to a big surprise because the full core of the unit 4 reactor had been moved and stored underwater at the spent nuclear fuel storage pool for periodic maintenance. It was because the possible criticality in the fuel storage pool by coolant loss may yield more severe situation than the similar accident happened inside the reactor vessel. Fortunately, it was assured to be evitable to an anxious situation by a look of water filled in the storage pool later. In the paper, the safety state of the spent fuel storage pool and rack structures of the domestic nuclear plants would be roughly reviewed and compared with the Fukushima plant case by engineering viewpoint of potential severe accidents.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.244-248
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• 2007

The contents of total phenol and total flavonoid of artichoke (Cynara scolymus L.) were measured. The antioxidant activity of the artichoke was evaluated based on its potential as a scavenging the ABTS radical. These results showed the antioxidant activity of artichoke has a close relationship with the total flavonoid content. The compound showing antioxidant activity was isolated from the artichoke by repeated column chromatography and recrystallization. Based on the spectrometric studies, the compound was identified as 1,3-dicaffeoylquinic acid, known as cynarin. The content of cynarin from heads and leafs of the artichoke determined by $C_{18}$ reversed phase HPLC (high-performance liquid chromatography) coupled with photodiode array detector was 10.15 and 0.67 mg/g, respectively. This compound showed potent antioxidant activities against DPPH and ABTS radicals ($EC_{50}$ = 14.09 and 28.85 ${\mu}M$, respectively).

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.55-68
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• 2020

Because of the intensified environmental problems such as climate change and resource depletion, sewage treatment technology focused on energy management has recently attracted attention. The conversion of primary sludge from the primary sedimentation tank and excessive sludge from the secondary sedimentation tank into biogas is the key to energy-positive sewage treatment. In particular, the primary sedimentation tanks recover enriched biodegradable organic matter and anaerobic digestion process produces methane from the organic wastes for energy production. Such technologies for minimizing oxygen demand are leading the innovation regarding sewage treatment plants. However, sewage treatment facilities in Korea lack core technology and operational know-how. Actually, the energy potential of sewage is higher than sewage treatment energy consumption in the sewage treatment, but current processes are not adequately efficient in energy recovery. To improve this, it is possible to apply chemically enhanced primary treatment (CEPT), high-rate activated sludge (HRAS), and anaerobic membrane bioreactor (AnMBR) to the primary sedimentation tank. To maximize the methane production of sewage treatment plants, organic wastes such as food waste and livestock manure can be digested. Additionally, mechanical pretreatment, thermal hydrolysis, and chemical pretreatment would enhance the methane conversion of organic waste. Power generation systems based on internal combustion engines are susceptible to heat source losses, requiring breakthrough energy conversion systems such as fuel cells. To realize the energy positive sewage treatment plant, primary organic matter recovery from sewage, biogas pretreatment, and co-digestion should be optimized in the energy management system based on the knowledge-based operation.

• Journal of the Mineralogical Society of Korea
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• v.24 no.2
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• pp.133-143
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• 2011

In Mujoo area, the granitic pegmatites are developed in the granitic gneiss complex with Jurassic gneissic granites, where Nb-Ta mineralization were reported. Pegmatites are mainly composed of large crystals of quartz, feldspars of end-member orthoclase and albite, and muscovite. Nb-Ta minerals in study area are columbite (Nb > Ta) in composition. Chemistry of muscovites shows post-magmatic in origin and they are closely related with columbite. Large columbite, in pegmatites occurred with quartz and feldspars, while microcrystalline columbite is associated with muscovite. The Nb contents in large columbite are relatively higher than those in microcrystalline ones. Two pegmatites, 4~15 m in width and 120 m, 250 m in extension respective1y, are developed. Five drilling cores with total 600 m in length are finally obtained and revealed no possible potential for economic rare metals of Na-Ta deposits.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.795-801
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• 2014

STEP Cube Lab. classified as a pico-satellite has been being developed by SSTL(Space Technology Synthesis Laboratory) in Chosun University. Its main mission objective is to perform the on-orbit verification of core space technologies, which will be the potential candidates for future space missions. In this paper, to guarantee successful mission operation of the cube satellite under extremely severe space thermal environment condition, the system level thermal design and analysis has been performed. The effectiveness of the design has been verified through on-orbit thermal analysis of cube satellite.

• Korean Journal of Community Nutrition
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• v.13 no.1
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• pp.91-99
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• 2008

The present study was conducted to examine metabolic risk factors and total antioxidant capacity (TAC) of Korean females living in Seoul and to investigate the relationship between the metabolic risk factors and serum TAC. A total of 353 females aged between 20 and 64 participated in the study. Obesity indicators, blood pressure, serum lipid profile and fasting blood glucose were measured as metabolic risk factors. Ferric reducing antioxidant power (FRAP) assay was employed to determine serum TAC of subjects. Obesity indicators such as body mass index, waist circumference and waist-hip ratio were significantly higher in the participants aged $\geq$ 50 y (older group) than in the participants aged 20-49 y (younger group) (p < 0.001). Blood pressure, serum total cholesterol (TC), triglyceride (TG) and fasting blood glucose were also significantly higher in the older group than in the younger group (p < 0.001), demonstrating significant positive correlations between age and MS risk factors. The association between FRAP and MS risk factors were also investigated. FRAP values showed significant positive correlations with age (p = 0.001), serum TG (p = 0.002) and TC (p = 0.03). A tendency of positive association between FRAP and waist circumference was observed without any significant difference (p = 0.06). Increased serum FRAP with central obesity and serum lipids may be interpreted as results of activation of antioxidant defense system against oxidative stress induced by metabolic syndrome (MS) constituent factors. However, to verify the function of FRAP as a potential biomarker of susceptibility to MS various contributors to the plasma antioxidant capacity and their biological relevance related to MS should be elucidated further.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4398-4417
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• 2017

Multi-user Multiple-Input and Multiple-Output (MU-MIMO) has potential for prominently enhancing the capacity of wireless network by simultaneously transmitting to multiple users. User selection is an unavoidable problem which bottlenecks the gain of MU-MIMO to a great extent. Major state-of-the-art works are focusing on improving network throughput by using Channel State Information (CSI), however, the overhead of CSI feedback becomes unacceptable when the number of users is large. Some work does well in balancing tradeoff between complexity and achievable throughput but is lack of consideration of fairness. Current works universally ignore the rational utilizing of time resources, which may lead the improvements of network throughput to a standstill. In this paper, we propose TOUSE, a scalable and fair user selection scheme for MU-MIMO. The core design is dynamic-time-warping-based user selection mechanism for downlink MU-MIMO, which could make full use of concurrent transmitting time. TOUSE also presents a novel data-rate estimation method without any CSI feedback, providing supports for user selections. Simulation result shows that TOUSE significantly outperforms traditional contention-based user selection schemes in both throughput and fairness in an indoor condition.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.131-139
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• 2009

The existing vessel monitoring system using the ground surveillance radar has a difficulty in monitoring ships continuously due to the limited range of detecting ships. For resolving this problem, we carry out a research on ship detection which is to be the core technology of vessel monitoring system for ocean monitoring using SAR imagery. There are two different methods of detecting ships in SAR imagery: detection of the ship target itself and detection of the ship wake. In this paper, we mainly focus on algorithms which detect the ship itself, and also present the accuracy test after extracting positional and directional figures of the ships. After rectifying input SAR imagery using polynomial transformation, we use Wiener filter to remove speckle noises. A labeling technique and morphological filtering in conjunction with Otsu's method are used to automatically detect the ships based on the image processing domain. For ground truth data, information from a radar system is used, which allows assessing the accuracy of the proposed method. The results show that the proposed method has the high potential in automatically detecting the ships and its positional/directional figures in a fast way.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.246-249
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• 2011

SolarPACES is an international cooperative network bringing together teams of national exports from around the world to focus on the development and marketing of concentrating solar power systems (also known as solar thermal power systems). It is one of a number of collaborative programs, called Implementing Agreements, managed under the umbrella of the International Energy Agency to help find solutions to worldwide energy problems. Technology development is at the core of the work of SolarPACES. Member countries work together on activities aimed at solving the wide range of technical problems associated with commercialization of concentrating solar technology, including large-scale system tests and the development of advanced technologies, components, instrumentation, and systems analysis techniques. In addition to technology development, market development and building of awareness of the potential of concentrating solar technologies are key elements of the SolarPACES program The Implementing Agreement specifies broad "Tasks," or thematic areas of work SolarPACES currently has three ongoing tasks, focusing on concentrating solar electric power systems (Task I), solar chemistry research (Task II), and solar technology and applications (Task III). An Operating Agent, nominated by the ExCo, is responsible for overseeing the work of each task Each task maintains a detailed program of work that defines all task activities, including their objectives, participants, plans, and budgets. In addition to technical reports of the activities and their participants, accomplishments and progress are summarized in the SolarPACES annual report. Many SolarPACES activities involve close cooperation among member countries (either through sharing of task activities or, occasionally, cost-sharing), although some cooperation is limited to sharing of information and results with other participants. In this paper, structure, works, and members of SolarPACES and Korean activies in the SolarPACES are introduced.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.1-8
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• 1993

This study was conducted to find the potential of polyethylene wrapping, ethylene scrubber, and Prolong as postharvest application in oriental pear, 'Niitaka'. Polyethylene film($30{\mu}m$) wrapping greatly reduced weight loss during storage for 80 to 110 days but the occurrence of dark skin browning became severe because of high humidity in polyethylene bags. Also, in long term storage of 110 days, parts of fruit developed uneven skin disorder or rupturing of cuticle layer. Ethylene scrubber reduced uneven skin disorder but no beneficial effect was found on the prevention of core breakdown. This indicates that the ethylene scrubber probably be effective when applied dicrectly to the storage room. The immediate application of Prolong to harverted fruit was confirmed not to be useful as postharvest treatment in 'Niitaka' pears.