• Food Science and Preservation
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• v.16 no.2
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• pp.299-303
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• 2009

To explore the preservation parameters of a prototype anti-inflammatory drink containing a Helianthus annuus seed extract, we first examined sweetness, pH and color changes, and temperature effects during preservation. Over 25 days, pH rose slightly from 3.50 to 3.65. Small color changes in L, a, and b values occurred on prolonged storage. Temperature most affected storage properties, which differed considerably at $10^{\circ}C$ and $40^{\circ}C$. Microbiological safety tests showed that the prototype drink was safe; neither general bacterial contamination nor Escherichia coli growth occurred. We concluded that the prototype drink was biologically and microbiologically safe on preservation.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1038-1044
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• 1996

The salt-fermented anchovy sauce (AS) was packed in round No. 307-1 can, and thermally processed at $121.1^{\circ}C$ to obtain Fo values of 3, 5 and 10. The changes of food components and qualifies by thermal processing of sterilized AS (RAS) were examined. The compositions of AS were as followed; pH 6.81, VBN 394.7 mg/100g, total nitrogen 2,195.5 mg%, amino-nitrogen 1,010.5 mg%, and acidity 10.5 ml. Viable cell counts of AS on 0%, 5%, 20% NaCl-medium were $2.9{\times}10^3,\;9.1{\times}10^3$ and not detected, respectively. And viable cell counts of RAS were not detected. Acidity, total nitrogen and amino nitrogen contents of AS decreased slightly with the severeness of heat treatments, whereas pH and VBN content were increased. Total free amino acid contents of raw AS and RAS were 12,802.5 mg% and $11,212.6{\sim}12,105.4\;mg%$, and major amino acids were alanine, glutamic acid, leucine, isoleucine, valine and lysine. Also contents of IMP, hypoxanthine, TMAO and TMA in AS and RAS were 42.1 mg% and $35.5{\sim}40.9\;mg%$, 103.7 mg% and $103.1{\sim}105.5\;mg%$, 78.8 mg% and $58.2{\sim}71.6\;mg%$, 55.8 mg% and $58.9{\sim}68.5\;mg%$ respectively. And a little changes were observed in whole volatile components of AS with severeness of heat treatments by GC chromatogram patterns. Judging from the chemical and sensory evaluations, the Fo 3 heat treatment sample was not inferior to raw AS, and maintained good quality for 1 year storage.

• Electronics and Telecommunications Trends
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• v.16 no.4 s.70
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• pp.54-66
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• 2001

본 논문은 지금까지 제안 및 개발되어 온 암호화 파일시스템에 대하여 살펴본다. 암호화 파일시스템은 사용자 개개인 혹은 조직 등에서 기밀을 유지하여야 하는 중요한 데이터에 대한 안전한 저장을 목적으로 개발되었다. 암호화 파일시스템의 기능으로는 침입자 혹은 원하지 않는 타인의 접근에 대해 데이터의 기밀성 및 안정성을 보장하고, 암호화 기능의 투명화를 통해 사용의 편리성을 제공하며, 암호화 기능의 수행으로 인해 시스템의 성능이 저하되는 것을 방지하는 것 등이 있다. 현재까지 개발되어 온 대표적인 암호화 파일시스템으로는 Cryptographic File System(CFS), Transparent Cryptographic File System(TCFS), Cryptfs, 그리고 Steganographic File System(StegFS) 등이 있다. 차후에는 분석된 암호화 파일시스템을 통해 좀 더 효율적인 보안성과 이식성을 제공하고, 사용자에 대해 편리성을 제공하는 파일시스템 구조의 설계 및 개발이 필요하다.

• Annual Conference of KIPS
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• 2022.11a
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• pp.893-895
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• 2022

기술의 무궁한 발전을 이루고 있는 현대사회에서도 전기 산업 현장에서는 크고 작은 사고가 빈번하게 발생하고 있다. 그에 따라 해당 장비는 안정성, 자율성, 내구성을 겸비하고, 무선 통신 시스템을 갖추어 위험 요소와 작업자 간 사이를 이격시켜 안전한 작업 환경을 구축 및 제공한다. 원격 제어 외에도 장비 자체의 결함 감지, 악력 측정, 실시간 영상 제공, 작업 데이터 저장 기능 등 다양한 서비스를 추가하여 제품의 완성도 및 실용성을 증가, 사용자의 작업 편의를 보장한다.

• Journal of the Korean Geotechnical Society
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• v.40 no.4
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• pp.169-178
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• 2024

While stable mid- to large-scale underground hydrogen storage infrastructures are needed to meet the rapidly increasing demand for hydrogen energy, evaluating the safety of explosion vibrations in adjacent buildings is becoming important because of gas explosions in underground hydrogen storage facilities. In this study, a numerical analysis of vibration safety effects on nearby building structures was performed assuming a hydrogen gas explosion disaster scenario in a low-depth underground hydrogen storage facility. A parametric study using a meta-model was conducted to predict changes in ground dynamic behavior for each combination of ground properties and to analyze sensitivity to geotechnical influencing factors. Directly above the hydrogen storage facility, the unit weight of the ground had the greatest influence on the change in ground vibration due to the explosion, whereas, farther away from the facility, the sensitivity of dynamic properties was found to be high. In addition, in evaluating the vibration stability of ground building structures based on the predicted ground vibration data and blasting vibration tolerance criteria, in the case of large reinforced concrete building structures, the ground vibration safety was guaranteed with a separation distance of about 10-30 m.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.8-14
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• 1996

The effects of temperature variations during storage, pasteurization on the quality of orange juices were investigated. To evaluate the quality of orange juices pasteurized at 75, 85 and $95^{\circ}C$ for 15 sec, microbial and physicochemical measurements and sensory evaluations were conducted during storage at 10, 20 and $30^{\circ}C$ for 32days. Color(lightness) and contents of vitamin C and sucrose were not changed at $10^{\circ}C$, but decreased at $20^{\circ}C$ and $30^{\circ}C$ as the storage time was increased. The pasteurization temperature had a little effect on the color and the contents of vitamin C and sucrose. Furfural contents were apparently increased as the storage period extended, but the samples stored at $10^{\circ}C$ had less amounts than the others. On the other hand, the pasteurization temperature did not affect furfural accumulation. Furfural was produced as a result of the degradation of vitamin C and deterioration of the color. The PH values were not changed during the entire storage period, and microorganisms were not detected in most of the samples. The result of sensory evaluation indicated no taste difference between the control and the sample stored at $10^{\circ}C$, but the taste changes were recognized when the samples were stored over 24 and 20 days at $20^{\circ}C$ and $30^{\circ}C$, respectively. Therefore, the storage temperature affected the quality of orange juices more markedly than the pasteurization temperature, and the storage at lower temperature appears to reduce the deterioration of orange juices.

• Clean Technology
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• v.27 no.4
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• pp.277-290
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• 2021

A supercapacitor, also called an ultracapacitor or an electrochemical capacitor, stores electrochemical energy by the adsorption/desorption of electrolytic ions or a fast and reversible redox reaction at the electrode surface, which is distinct from the chemical reaction of a battery. A supercapacitor features high specific power, high capacitance, almost infinite cyclability (~ 100,000 cycle), short charging time, good stability, low maintenance cost, and fast frequency response. Supercapacitors have been used in electronic devices to meet the requirements of rapid charging/discharging, such as for memory back-up, and uninterruptible power supply (UPS). Also, their use is being extended to transportation and large industry applications that require high power/energy density, such as for electric vehicles and power quality systems of smart grids. In power generation using intermittent power sources such as solar and wind, a supercapacitor is configured in the energy storage system together with a battery to compensate for the relatively slow charging/discharging time of the battery, to contribute to extending the lifecycle of the battery, and to improve the system power quality. This article provides a concise overview of the principles, mechanisms, and classification of energy storage of supercapacitors in accordance with the electrode materials. Also, it provides a review of the status of recent research and patent, product, and market trends in supercapacitor technology. There are many challenges to be solved to meet industrial demands such as for high voltage module technologies, high efficiency charging, safety, performance improvement, and competitive prices.

• Tunnel and Underground Space
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• v.16 no.4 s.63
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• pp.296-306
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• 2006

It is difficult to solve problems regarding the adjustment on demand and supply of LNG due to seasonal variations of domestic demand of LNG, a discordance among import pattern and limits of storage facilities and so on. Also, there may be instability in LNG supply due to chances of accidents at LNG producing areas. Therefore, it is very important to secure large LNG storage facilities and to stabilize LNG supply management on a long term basis. The objective of this study is to examine the real-scale applicability of a lined underground rock storage system, which have been verified by a successful operation of the Daejeon LNG pilot plant. The new technology has many advantages of better economy, safety and environment protection, for above-ground and in-ground storage systems. The results of this study may promote the first ever real scale underground LNG storage system in a rock cavern.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.217-246
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• 2018

During the selection and characterization of target formations in the Small-scale Offshore $CO_2$ Storage Demonstration Project in the Pohang Basin, we have carefully investigated the possibility of induced earthquakes and leakage of $CO_2$ during the injection, and have designed the storage processes to minimize these effects. However, people in Pohang city have a great concern on $CO_2$-injection-intrigued seismicity, since they have greatly suffered from the 5.4 magnitude earthquake on Nov. 15, 2017. The research team of the project performed an extensive self-investigation on the safety issues, especially on the possible $CO_2$ leakage from the target formation and induced earthquakes. The target formation is 10 km apart from the epicenter of the Pohang earthquake and the depth is also quite shallow, only 750 to 800 m from the sea bottom. The project performed a pilot injection in the target formation from Jan. 12 to Mar. 12, 2017, which implies that there are no direct correlation of the Pohang earthquake on Nov. 15, 2017. In addition, the $CO_2$ injection of the storage project does not fracture rock formations, instead, the supercritical $CO_2$ fluid replaces formation water in the pore space gradually. The self-investigation results show that there is almost no chance for the injection to induce significant earthquakes unless injection lasts for a very long time to build a very high pore pressure, which can be easily monitored. The amount of injected $CO_2$ in the project was around 100 metric-tonne that is irrelevant to the Pohang earthquake. The investigation result on long-term safety also shows that the induced earthquakes or the reactivation of existing faults can be prevented successfully when the injection pressure is controlled not to demage cap-rock formation nor exceed Coulomb stresses of existing faults. The project has been performing extensive studies on critical stress for fracturing neighboring formations, reactivation stress of existing faults, well-completion processes to minimize possible leakage, transport/leakage monitoring of injected $CO_2$, and operation procedures for ensuring the storage safety. These extensive studies showed that there will be little chance in $CO_2$ leakage that affects human life. In conclusion, the Small-scale Offshore $CO_2$ Storage Demonstration Project in the Pohang Basin would not cause any induced earthquakes nor signifiant $CO_2$ leakage that people can sense. The research team will give every effort to secure the safety of the storage site.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.521-528
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• 1986

In this paper, proteolytic activity of the tissue extracts from the internal organs such as alimentary canal, pancreas, pyloric caeca, stomach, liver and spleen of mackerel, Scomber japonicus, and sardine, Sardinops melanosticta, was compared with each other under the optimum reaction condition. The proteinases distributed in alimentary canal, pancreas, pyloric caeca and spleen were active in alkaline pH range, but those in stomach were shown the activity in acid pH range, furthermore those in liver were exhibited the activity in acid, neutral and alkaline pH range. The proteinases distributed in the internal organs of both fish were stable at the heat treatment of $45^{\circ}C$ for 5 minutes. The proteinases from stomach and pyloric caeca of the two fish and those from pancreas of sardine were less stable than those from any other internal organs of both fish. Whereas the proteinases from spleen and neutral proteinases from liver were shown to be stable by the heat treatment at $55^{\circ}C$ for 5 minutes. The proteinases from pyloric caeca of both fish, and stomach, pancreas and spleen of mackerel were stable during the whole storage days at $5^{\circ}C$, but the other proteinases were slowly inactivated after 14 days of storage. The enzymes were seemed to be more stable in the storage at $-15^{\circ}C$ than at $5^{\circ}C$.