• Food Science of Animal Resources
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• v.40 no.5
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• pp.813-830
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• 2020

In this study, the potential of infrared assisted freeze-drying (IRAFD) was tested for the production of shelf-stable edible insects: Protaetia brevitarsis larva (larva of white-spotted flower chafer). The IRAFD system was customized using an infrared lamp, K-type thermocouple, controller, and data acquisition system. The infrared lamp provided the sublimation energy for rapid freeze-drying (FD). The IRAFD conditions were continuous IRAFD-5.0 kW/㎡ and IRAFD-5.0 kW/㎡ at different weight reduction (WR) (10%, 20%, and 30%). The continuous IRAFD reduced the drying time to 247 min compared to the 2,833 min duration of FD (p<0.05). The electrical energy could be reduced by more than 90% through infrared radiation during FD (p<0.05). The Page model resulted in the best prediction among the tested drying kinetic models. In terms of quality, IRAFD showed significantly lower hardness, chewiness, and higher protein levels than hot air drying and FD (p<0.05). IRAFD better preserved the glutamic acid (6.30-7.29 g/100 g) and proline (3.84-5.54 g/100 g). The external product appearance after IRAFD exhibited more air pockets and volume expansion, which might result in a good consumer appeal. In conclusion, this study reports the potential of IRAFD in producing shelf-stable and value-added edible insects.

• Atmosphere
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• v.26 no.1
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• pp.73-84
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• 2016

A method to make ice spike using home refrigerator with ice tray was found. Many experiments have carried out with this method and many natural phenomena occurring on the formation of ice spike are found. A new concept of the Latter Freezing Water (LFW) was imported to explain the ice spike formation. At LFW position on water surface, the Sprout of Super cooled Water (SSW) grows by the Volume Expansion Effect (VEE) caused by the phase change of water in water. And air bubbles that are expelled from ice during freezing process, gather, rise, and detonate at the upper most part of SSW that make SSW freeze and grow upward with the water pipe in it. Together with VEE the capillarity in the water pipe makes the column grow more, that makes the ice spike. Many other findings were succeeded; 1) Ice spike process is completed before the whole water freezes. 2) If water is corrupted or shocked, even though it is very slight, ice spike is not generated. 3) Rain water contains the most LFW among all kind of waters used in experiments. 4) LFW is changed into normal water after passing the ice spike. 5) A new concept of the ice bullet is introduced. 6) The reason of frequent occurrences of the ice spike at Mt. Mai is investigated also.

• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.236-241
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• 1976

A barley (20-30%)-wheat (80-70%) flour gave generally acceptable noodle-making characteristics, in which naked barley flour showed somewhat better results than covered barley flour. And also for over 40% barley flour in the barley-wheat flour, the addition of xanthan gum improved the noodle-making characteristics. A naked barley-defatted soy flour could make dried noodles with only high NSI (Nitrogen Solubility Index) defatted soy flour, however this mixture was not considered to be feasible for noodle-making. In cooking characteristics of barley-wheat flour noodles, naked barley flour was more acceptable than covered barley flour and xanthan gum influenced the water absorption and volume expansion of noodles during cooking. The firmness, cohesiveness and gumminess in cooked noodles made of the barley-wheat flour increased and then decreased as the amounts of barley increased. The mixing of defatted soy flour (high NSI) to naked barley flour increased the firmness and gumminess of cooked noodles.

• Journal of Korea Foundry Society
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• v.33 no.4
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• pp.157-161
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• 2013

A ribbon-type polycrystalline silicon wafer was directly fabricated from liquid silicon via a novel technique for both a fast growth rate and large grain size by exploiting gas pressure. Effects of processing parameters such as moving speed of a dummy bar and the length of the solidification zone on continuous casting of the silicon wafer were investigated. Silicon melt extruded from the growth region in the case of a solidification zone with a length of 1cm due to incomplete solidification. In case of a solidification zone wieh a length of 2 cm, on the other hand, continuous casting of the wafer was impossible due to the volume expansion of silicon derived from the liquid-solid transformation in solidification zone. Consequently, the optimal length of the solidification zone was 1.5 cm for maintaining the position of the solid-liquid interface in the solidification zone. The silicon wafer could be continuously casted when the moving speed of the dummy bar was 6 cm/min, but liquid silicon extruded from the growth region without solidification when the moving speed of the dummy bar was ${\geq}$ 9 cm/min. This was due to a shift of the position of the solid-liquid interface from the solidification zone to the moving area. The present study reports experimental findings on a new direct growth system for obtaining silicon wafers with both high quality and productivity, as a candidate for an alternate route for the fabrication of ribbon-type silicon wafers.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1131-1137
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• 2004

With the recent continuous expansion of subways, newly created subways tend to have lower locations and wider sections. Furthermore. since box structures and evacuating tunnels are classified into a category of mass-concrete. the thermal-stress, emitted from the inside. causes cracks to structures from the inception of constructing. In this paper, thermal-stress analysis and durability evaluation of box structure were carried out to investigate relationship between durability and parameter causing the heat of hydration. Through the examination, this paper tries to find out satisfactory solutions to regulated thermal crack and ensure the required duration period. The results of this paper showed that to control thermal crack and guarantee the required duration period it was more effective to use low-heat-portland cement and moderateheat-portland cement. As cement volume due to reduction of water-cement ratio increased, the possibility of thermal cracks occurrence increased but results of durability evaluation was different depending on evaluation method. The results showed that the appropriate water-cement ratio to control the heat of hydration and satisfy the required durability was $45\∼55\%$. And it was showed that during placement of concrete blocks ambient temperature affect the heat of hydration. thermal crack and long-term durability largely and when concrete was placed at low temperature to control thermal crack. it need to try to guarantee the required duration period. Henceforth, by studying not only internal and external conditions, such as the relative humidity and the unit weight. but also methods, to evaluate durability, in accordance with domestic situations, more reasonable design of durability should be achieved.

• International Commerce and Information Review
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• v.6 no.2
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• pp.265-285
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• 2004

The objective of this study has two folds. The first is to investigate current global certification system and the second is to suggest some possible solutions for expanding global e-trade networks. Both research and industrial communities recognize the importance of global certification problems in connection with global e-trade payment because global e-trade volume continue to grow. But not many research results have been reported to the communities in identifying some barriers against active global certification systems. This paper intents to suggest some possible solutions for improved global certification system and the results are summarized as follows: First, strict certification structure has to be relaxed by considering diverse mutual certification methods in global e-trade practice. This paper provides some comparative results about mutual certification methods among different nations. Second, numerous business models have to be derived such that they can be applied to other global certification applications than global e-trade. Third, global certified networks have to be expanded beyond mutual certification level. Once the certified structure among different nations have been established then diverse certified authority channels have to be implemented. Finally, since Korea has already established very good public certification infrastructure within the nation this platform has to be positioned in the center of global e-trade networks. This paper has of course to accept a critique such as this study provided limited results to generalized global e-trade certification model, and therefore empirical study for assessing robust model should be pursued in the future.

• Composites Research
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• v.28 no.4
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• pp.226-231
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• 2015

Various characteristics(thermal expansion, microstructure, etc.) and mechanical properties of CNT-aluminum nano composites manufactured by volume production system were evaluated. Also, formability and durability were evaluated for potential applications in automotive parts, via compared with high-elasticity material (A390) and the current commercial product. As a result, this composite has excellent mechanical properties and formability, therefore, to verity its potential for application as light and high strength materials in automobile part.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.846-850
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• 2011

Nanocomposite anodes for rechargeable lithium battery are prepared by mixing tin and nickel nanoparticles via wet method and their electrochemical properties are examined. The Sn-Ni nanocomposite anode shows a maximum discharge capacity of 700 mAh $g^{-1}$ at the first cycle but very poor cycle performance. This means that the electrode porosity and the Ni component formed by the simple mixing of nanoparticles no longer play the role of buffering the volume expansion/contraction of Sn component during charge-discharge. To solve the cycle performance problem, a novel nanostructured Sn-Ni anode should be designed and tested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.133-141
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• 2017

Traffic volume increases according to highway expansion and industrial development which causes repetitive defect and durability degradation on pavement. The research of quality assurance system used abroad has introduced Korea. Korea Expressway Corporation (KEC) has developed a Quality Performance Index (QPI) that quantitatively assesses the level of quality of the final product, and practical applications. Assessment factor on concrete pavement consisted of pavement thickness, compressive strength, IRI and spacing factor. Assessment factor on concrete pavement is determined by empirical evaluation factor from abroad. In this study, analysis of evaluation factors of concrete pavement by using pavement life prediction simulation and measured data were evaluated with consideration of feasibility of the assessment factor. Pavement life, performance and durability are affected by pavement thickness, compressive strength, IRI and spacing factor in assessment factor on concrete pavement, QPI.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.17-25
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• 2017

Relocation and expansion of existing port facilities are necessary given this increase in marine traffic volume and the presence of larger entering vessels. Therefore, this study focused on anchorage among water facilities, and examined the degree of harmony between anchorage and other water facilities at Yeosu Kwangyang Port. The number of anchoring vessels in relation to anchorage over the past 5 years, total anchored hours by anchorage-years, average number of simultaneously anchored vessels by anchorage-years, maximum number of simultaneously anchored vessels by anchorage, and maximum size of anchored vessels by anchorage have been surveyed. The minimum anchorage radius has been calculated according to the designated anchorage capacity according to anchorage. Finally, improvement plans for Yeosu Kwangyang Port's anchorage have been suggested, including relocating of Yeosu no. 2 anchorage, expanding of Kwangyang no. 1 ~ 5 anchorage, relocating of Kwangyang no. 8 ~ 9 anchorage, and repealing of Kwangyang no. 11 anchorage.