• Journal of the Korean GEO-environmental Society
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• v.14 no.10
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• pp.49-57
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• 2013

Recently, recycling of the industrial by-products has been an important issue of the Yeosu bay, where large industrial complex is located. Major industrial by-products which are produced from Yeosu industrial complex area are phosphogypsum and flyash, which are about 82% and 10% of the 1.6 million tons industrial by-products. Moreover since the Yeosu industrial complex is located at seaside, phosphogypsum has been pointed as cause of serious environmental contaminant from the regional society. Therefore recycling study can't be delayed anymore. In this paper, artificial aggregate was manufactured by non-sintering process from industrial byproducts - e.g., phosphogypsum and slag - as a geotechnical drainage material. To show the feasibility of the artificial aggregate as a geotechnical drainage material, geotechnical experiments including particle size analysis, permeability test, and large scale direct shear test were carried out. Test results show that the permeability of the artificial aggregates range from $6.94{\times}10^{-1}cm/sec$ to $8.86{\times}10^{-1}cm/sec$, which is much larger value than those are required for the drainage material from the construction specification in Korea, and the friction angle of the artificial aggregate is as large as that of sand in water immersion conditions. From the test results, it was concluded that artificial aggregate made from industrial by-products can be used successfully as a geotechnical drainage material.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.160-170
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• 2017

As a monumental building in the form of an arch, an archway has the characteristics of praise and honor. More and more historic, cultural and social connotations are given during the development of history. Four archways that are located on the middle route of the Red Gate Palace in the Mount Tai Scenic Area were chosen for research. Based on a literature review and field investigation with a visual analysis method, the physical attributes, spatial scale, perceptions and functions of the archways were discussed. The results were as follows: The archways in the research area are all made of stone. According to building location, they are classified into two types: Cultural archway and temple archway. Regarding functions, they are divided into symbolic archway, memorial archway and portal archway. From the point of view of form and scale, the Confucius Boarding Archway enjoys a higher standard than the other three. This reflects the importance of Confucian culture on Mount Tai. Regarding spatial scale, the archway becomes the focus in a restrictive linear space by an object-to-object and person-to-object comparison. Visitor experience of crossing the archways is strongly enhanced as it acts as entrance and exit, and it has the function of guiding sight since the arrangement of the archways further extend the line of sight. Couplets and inscriptions on the archways increase a sense of expectation for visitors on their way to the top of Mount Tai.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.177-182
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• 2020

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/㎠ UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120℃ for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110℃ for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121℃, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.414-414
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• 2017

토양수분은 지면환경에서 일어나는 수문 및 에너지 순환을 이해하는 데 있어 중요한 기상인자이다. 토양수분 현장관측은 땅속에 매설된 센서에 의해 상당히 정확하게 이루어지만, 관측점 수가 충분치 않아 공간적 연속성을 확보하지 못하는 어려움이 존재한다. 이에 광역적 및 연속적 관측이 가능한 마이크로파 위성센서가 토양수분 정보 획득을 위한 보조수단으로서 그 중요성이 부각되고 있다. 마이크로파 위성센서는 구름 등 기상조건의 제약을 받지 않으며, 1978년 이래 현재까지 여러 위성에 의해 25 km 및 10 km 해상도의 전지구 토양수분자료가 생산되어 왔다. 마이크로파 센서를 이용한 토양수분자료는 동일지점에 대하여 하루 2회 정도 산출되므로 적절한 시간분해능을 가지지만, 공간해상도가 최고 10 km로서 지역규모의 수문분석에 적용하기에는 충분치 않다. 이러한 토양수분자료의 공간해상도 문제 해결을 위하여 다양한 지면환경요소를 활용한 통계적 다운스케일링이 대안으로 제시되었다. 최근의 선행연구들은 대부분 방정식을 이용한 결합모형을 통해 통계적 다운스케일링을 수행하였는데, 회귀식과 같은 선형결합뿐 아니라 신경망이나 기계학습 등의 비선형결합에서도, 불가피하게 발생할 수밖에 없는 잔차(residual)로 인하여 다운스케일링 전후의 공간분포 패턴이 달라져버리는 문제를 안고 있었다. 회귀분석에 잔차의 공간내삽을 결합시킨 회귀크리깅(regression kriging)은 잔차보정을 통해 이러한 문제를 해결함으로써 다운스케일링 전후의 공간분포 일관성을 보장하는 기법이다. 이 연구에서는 회귀크리깅을 이용하여 일자별 AMSR2(Advanced Microwave Scanning Radiometer 2) 토양수분 자료를 10 km에서 1 km 해상도로 다운스케일링하고, 다운스케일링 전후의 자료패턴 일관성을 평가한다. 지면온도(LST), 지면온도상승률(RR), 식생온도건조지수(TVDI)는 일자별로 DB를 구축하였고, 식생지수(NDVI), 수분지수(NDWI), 지면알베도(SA)는 8일 간격으로 DB를 구축하였다. 이러한 8일 간격의 자료를 일자별로 변환하기 위하여 큐빅스플라인(cubic spline)을 이용하여 시계열내삽을 수행하였다. 또한 상이한 공간해상도의 자료는 최근린법을 이용하여 다운스케일링 목표해상도인 1 km에 맞도록 변환하였다. 우선 저해상도 스케일에서 추정치를 산출하기 위해서는 저해상도 픽셀별로 이에 해당하는 복수의 고해상도 픽셀을 평균화하여 대응시켜야 하며, 이를 통해 6개의 설명변수(LST, RR, TVDI, NDVI, NDWI, SA)와 AMSR2 토양수분을 반응변수로 하는 다중회귀식을 도출하였다. 이식을 고해상도 스케일의 설명변수들에 적용하면 고해상도 토양수분 추정치가 산출되는데, 이때 추정치와 원자료의 차이에 해당하는 잔차에 대한 보정이 필요하다. 저해상도 스케일로 존재하는 잔차를 크리깅 공간내삽을 통해 고해상도로 변환한 후 이를 고해상도 추정치에 부가해주는 방식으로 잔차보정이 이루어짐으로써, 다운스케일링 전후의 자료패턴 일관성이 유지되는(r>0.95) 공간상세화된 토양수분 자료를 생산할 수 있다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.91-91
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• 2019

전북 완주군 농가에서 2017년 12월에 재배한 '시베리아'와 '메두사' 품종을 1시간 이내에 국립원예특작과학원 실험실로 이동하였다. 알약(SmartFreshTM, AgroFresh Inc., USA)형태의 1-MCP를 1.875g/3.55m3 기준으로 정량하여 Activator Kit(SmartFreshTM, AgroFresh Inc., USA)에 넣어 마개를 닫고 몇 번 흔들어주어 녹인 후 1.5 ppm이 되도록 처리하였으며 3시간 훈증 후 30분 환기하였다. 훈증처리 후 절화 백합은 유공 필름 슬리브를 이용하여 포장한 후 골판지상자에 넣어 모의 수출환경에서 수송방식은 건식(건조처리)상태로 $4^{\circ}C$ 저장고에 암상태로 저장하면서 무처리를 대조로 에틸렌 노출 조건 조성을 위하여 후레쉬라이프(탑프레쉬) 5g 봉지를 상자내부 5개, 상자외부 저장고 내에 10개로 총 15개의 에틸렌 발생제 처리를 하였다. 백합 절화 신선도 유지기간 연장을 위한 선도유지제 전처리 효과는 1.5 ppm 1-MCP 3시간 훈증처리에 의해 잎의 황화현상을 지연시키는 효과가 있었다. 전체적으로 판정한 절화수명은 '시베리아'는 무처리 9.0일, 1-MCP 훈증 9.0일, 에틸렌 발생제 8.3일, 1-MCP 훈증+에틸렌 발생제 9.5일이었으며 '메두사'는 무처리 6.5일, 1-MCP 훈증 7.5일, 에틸렌 발생제 5.7일, 1-MCP 훈증+에틸렌 발생제 8.5일로 나타났다. 에틸렌에 노출은 꽃의 빠른 노화를 야기하여 절화수명을 단축 시켰으며 이상개화를 보이는 꽃도 있어 상품성이 크게 떨어졌다. 1-MCP에 의해 잎의 황화 억제에 효과적이었으며 저장 중 에틸렌 발생제를 동시에 처리하였을 때 품질유지 효과가 더 크게 나타났으며 '메두사' 품종에서는 만개시 화색도 더 진하게 나타났다. 따라서, 저온저장이나 선적시 에틸렌 발생이 많은 품목과 혼합하게 될 것이 예상될 경우에 품질유지를 위해 1-MCP 훈증처리를 하면 효과적일 것으로 사료된다.

• Journal of the Korean Geotechnical Society
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• v.35 no.1
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• pp.31-42
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• 2019

About 3% of Casein is included in milk and it accounts for 80% of milk's protein. It has an adhesive property when mixed with calcium hydroxide and sodium hydroxide solutions. It has been usually used to bond woods under dry condition but becomes weak when exposed to moisture. Such weakness is very critical when casein is applied for soil cementation under groundwater condition. Therefore, this study was aimed to protect such weakness by changing or adding certain ingredients of casein adhesive. Two types of cemented specimens were prepared with Nakdong river sand and tested for unconfined compressive strength and durability. Each specimen was mixed with casein or cement. Ingredients of casein binder suggested by the University of Wisconsin, which is called a standard casein recipe, was also prepared. This study tried 6 different types of casein binder recipe. Among them, one with 30% hydroxide calcium increase and 50% hydroxide sodium decrease compared with the standard casein was most effective. Based on the most effective casein recipe, cemented sand with 1-4% of casein ratio was prepared and tested. The unconfined compressive strength and durability index were 6,253kPa and 92% for the specimen with 4% of casein ratio and 1,500kPa and 62% for the one with 8% of cement ratio. Therefore, casein cemented sand showed better performance. In addition, over 3% of casein cemented sand had over 80% durability index.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.498-505
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• 2020

Aggregate occupies about 70-85% of the concrete volume and is an important factor in reducing the drying shrinkage of concrete. However, when constructing high-rise buildings, it acts as a problem due to the high load of natural aggregates. If the load becomes large during the construction of a high-rise building, creep may occur and the ground may be eroded. Material costs increase and there are financial problems. In order to reduce the load on concrete, we are working to reduce the weight of aggregates. However, artificial lightweight aggregates affect the interface between the aggregate and the paste due to its higher absorption rate and lower adhesion strength than natural aggregates, affecting the overall strength of concrete. Therefore, in this study, in order to grasp the interface between natural aggregate and lightweight aggregate by type, we adopted a method of measuring electrical resistance using an EIS measuring device, which is a non-destructive test, and lightweight bone. The change in the state of the interface was tested on the outside of the material through a blast furnace slag coating. As a result of the experiment, it was confirmed that the electric resistance was about 90% lower than that in the air-dried state through the electrolyte immersion, and the electric resistance differs depending on the type of aggregate and the presence or absence of coating. As a result of the experiment, the difference in compressive strength depending on the type of aggregate and the presence or absence of coating was shown, and the difference in impedance value and phase angle for each type of lightweight aggregate was shown.

• Journal of Conservation Science
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• v.37 no.2
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• pp.135-143
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• 2021

Conservation treatment that involved filling the lifting parts of wooden cultural heritage is carried out by obtaining wood or wood powder of the same species and mixing it with synthetic resin or natural glue to charge the blank area. Various concentrations and mixing ratios of adhesives and additives are used, depending on the type and condition of the target. Accordingly, in this study, we determined the conditions of the filler suitable for conservation treatment of wooden sculptures with lifted or separated bark in the National Museum of Modern and Contemporary Art. The optimal filler conditions for each adhesive were selected based on drying speed, shrinkage and expansion rates, and physical deformation degree. Then, to verify their actual applicability, these fillers were applied to wood and exposed to high-humidity environment and their cross-sections were observed. The fillers showed stable application in the following order: animal glue, PVAc adhesive, acrylic adhesive. In conclusion, a 1:2 mixture of animal glue and wood powder is a suitable filler for conservation treatment of wooden sculpture with lifted bark. The results of this study suggest appropriate ways to stabilize the bark that was lifted or separated from a wooden sculpture, thus enabling the future conservation treatment of the artworks under similar conditions.

• Journal of the Korean Geotechnical Society
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• v.38 no.12
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• pp.113-123
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• 2022

The required density relationship according to the press pressure of the floating die method and the homogeneity of the density distribution in the buffer block was evaluated to analyze the manufacturing characteristics of engineering scale bentonite-sand buffer blocks. In addition, the thermal conductivity was measured and compared with that of the pure bentonite buffer block to evaluate the level of thermal conductivity performance improvement of the bentonite-sand buffer material. As a result, it was confirmed that the standard deviation of dry density decreased to 0.011 and showed a homogeneous density distribution under the condition of press pressure greater than 400 kg/cm². Furthermore, as a result of the thermal conductivity test, the thermal conductivity of the buffer with optimum moisture content conditions was 1.345 and 1.261 W/(m·K) under the press pressure of 400 and 600 kg/cm², respectively. It increased by 16.1% and 11.0% compared to the pure bentonite buffer material. Based on the results of this study, it is judged that it can be used as fundamental data for manufacturing a homogeneous bentonite-sand buffer block on an engineering scale.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.77-85
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• 2022

Retinaldehyde (RA), vitamin A derivative, is an intermediate between retinol and retinoic acid and has an excellent wrinkle improving effect. In this study, Drug-in-cyclodextrin-in-liposome (DCL) was used to enhance the stability and skin penetration of RA. The complex of RA and hydroxypropyl-beta-cyclodextrin (HP-β-CD) was prepared by the freeze-drying method, and the presence or absence of inclusion of retinal was confirmed by UV-Vis spectrometer, FT-IR and SEM images. RA was captured in HP-β-CD about 95.6% on 1 : 15 (w/w). The retinal-HP-β-CD complex was encapsulated in liposomes using a homomixer and microfluidizer, with an average particle size of 215 ± 4.2 nm and a zeta potential of -31.2 ± 0.5 mv. In the evaluation of the degradation stability of RA, degradation rate of RA-HP-β-CD-liposomes in water was 1.8% higher than RA-liposome (5.8%), RA-HP-β-CD complex (9.7%) and RA alone (37.6%). RA cream (0.05% RA) including RA-HP-β-CD-liposomes was prepared for clinical test with wrinkle-improving efficacy and skin dermis denseness evaluated for 2 or 4 weeks. RA cream showed a significant wrinkle improving effect without skin irritation. In conclusion, it was confirmed that the double stabilization technology using the DCL system contribu tes to the effect of improving skin wrinkles by increasing the stabilization of retinal.