• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2C
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• pp.51-58
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• 2009

In this study, the small strain shear moduli ($G_{max}$) of uncemented and gypsum-cemented sands are evaluated by performing a series of bender element tests on the specimens reconstituted in the calibration chamber. It is observed from the experimental results that $G_{max}$ of crushed-sands is about 35~50% smaller than that of natural sands. The increase in gypsum content is observed to result in an exponential increase of $G_{max}$ value. It is also shown that the relative density has more significant effect on $G_{max}$ of cemented sand, whereas the vertical effective stress has more significant influence on $G_{max}$ of uncemented one. A prediction equation for cemented sand is expressed as a function of gypsum content as well as void ratio and vertical effective stress.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.247-247
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• 2010

본 연구는 주류 제조과정에서 발생하는 생전분발효 부산물을 펠릿(pellet)연료로 전환하는 과정에서 효율적인 방법에 대해 기술한다. 술을 정제하는 과정에서 발생하는 주박을 펠릿화하고 재생청정에너지인 폐자원의 효율성을 높이기 위한 방법을 제안한다. 술을 정제하고 남은 지게미를 주박(酒粕, 술지게미)이라 하고 흔히 부드러운 것을 단단하게 뭉친 알갱이를 펠릿이라 한다. 현재 펠릿화는 폐목재를 분쇄후 성형, 가공하여 목재펠릿을 만들어 상용화하고 있다. 목재펠릿은 성형, 가공하는데 비용이 주박보다 많이 들고 열량도 더 낮음을 확인하였다. 목재소에서 나온 나무(톱밥)와 주박을 열량측정기를 이용하여 측정한 결과로 나무는 약 1850 Kcal이고 주박은 약 1989 Kcal가 측정되었다. 나무는 일반 목재소 세 곳에서 채취한 것이고 주박은 막걸리, 약주 및 청주의 술지게미를 실험에 사용한다. 주류업체에서도 술을 정제하고 남은 주박을 처리하는데 많은 곤란과 비용이 든다. 또한 주박을 해양에 투척하여 처리해 왔으나 2012년부터 해양투기가 금지되어 더욱 처리에 곤란을 겪게 된다. 최근 주박을 토양개량제(비료)로 개발하여 사용하기도 하나 본 연구에서 제안하는 장점은 농산물을 재배해서 주류제조시 발생되는 주박을 펠릿화하여 연료로 사용하고 남은 재를 토양개량제로 사용하는 장점이 있다. 제품의 전체 라이프 사이클을 통해 환경으로 방출되는 모든 것을 가능한 한 0(zero)으로 하는 활동인 제로-이미션(zero-emision)이 된다. 이는 단순히 배출량만을 줄이는 것이 아니라 폐기물을 유용한 자원으로 활용한다는 측면이 가장 큰 이점이 된다. 주박의 효율성을 높이기 위해 주박을 종류별로 주박과 목재를 섞는 방법으로 열량을 측정하였다. 먼저 열량이 높은 순서로 막걸리 주박과 약주 주박의 비율을 1:1, 1:0.5, 1:0.2, 두 번째 막걸리 주박과 청주 주박의 비율을 1:1, 1:0.5, 1:0.2, 세 번째 막걸리 주박과 나무 톱밥의 비율을 1:1, 1:0.5, 1:0.2로 섞어서 열량을 측정하였다. 열량이 높은 순서는 세 번째(2015Kcal), 두 번째(1995Kcal), 첫 번째(1868Kcal)의 순이었다. 가장 열량이 높은 막걸리 주박과 나무 톱밥을 섞은 것이 가장 효율성이 높다. 주박 펠릿의 장점은 친환경적인 소재이고 지속적으로 재생이 가능한 에너지원이다. 더욱이 주박 펠릿은 발열량이 높고 다른 바이오매스 원료에 비해 청정하다는 큰 장점을 지니고 있다. 또한 사용에 소요되는 유지 관리비용을 최소화할 수 있고 자동화가 가능하여 사용에 편리하다. 가격면에서 화석연료에 비해 안정적이고 체적 또한 작아 이송의 큰 장점을 가지고 있다. 현재 펠릿의 경우는 목재펠릿이 제품화되어 있지만 주박을 이용하여 제품의 펠릿화를 통한 연료원으로 사용하는 경우는 전 세계 전무한 상태로 폐자원을 재사용하는 효율성이 제시된다. 향후 과제로 주박을 이용한 펠릿 연료원의 기술이 개발되고 기계적인 시스템을 개발하면 저탄소 녹색성장 신재생에너지 연료의 획기적인 미래형 에너지시스템이 될 것이다.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.89-98
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• 2017

The aim of this study was to compared the penetration scores and microleakage levels of flowable resin in comparison to resin-based pit and fissure sealant. A total 120 extracted premolars were used and classified with group I (resin-based pit and fissure sealant), group II (flowable resin), group III (bonding agent + flowable resin), IV (fissurotomy + bonding agent + flowable resin) depending on the materials and the application methods. The penetration scores of the group treated with flowable resin following fissurotomy were similar to those of the group treated with resin-based sealant, but higher compared to those of the other groups treated with flowable resin without fissurotomy or bonding agent. The group treated with flowable resin following fissurotomy also exhibited the lowest microleakage levels. The group treated with resin-based sealant and the one treated with a bonding agent prior to the application of flowable resin showed similar microleakage levels. In conclusion, flowable resin may be applied as a pit and fissure sealant, and its application along with fissurotomy could increase the penetration scores.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.523-530
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• 1999

Acrylic pressure-sensitive adhesive has been made utilizing organic solvents, but nowadays it is made by solvent-free system due to environmental problems. In this study, emulsion polymerization were carried out at $40^{\circ}C$ with methacrylic acid(MAA), n-butyl acrylate(n-BA) and 2-ethylhexyl acrylate(2-EHA) as monomers in the presence of anionic(sodium dodecyl sulfate, SDS) and nonionic(ethylene oxide types) surfactant mixtures. The overall conversion of the polymerization reaction in a mixed surfactant system was found to be higher than that in a single surfactant system. Emulsion stability in mixed or anionic surfactant systems was found to be over 12 week, which was better than that in nonionic surfactant system. Emulsion particle size decreased as surfactant content increased. The Tg and molecular weight of emulsion polymer were inependent of the type, the amount and the mixing ratio of surfactant. Based on the results of stability and peel strength, the optimum nonionic surfactant ratio in total 4 g of surfactant mixture systems is found to be 40~60% by weight where the nonionic surfactant has 50 ethylene oxide groups and 16~18 carbon atoms in hydrophobic alkyl chain.

• Applied Microscopy
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• v.38 no.4
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• pp.339-345
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• 2008

In this study, we compared the stress and tensile strength of the hair treated with oxidative permanent dye with those of virgin hair. We investigated the fine structure of the hair section after the tensile test using scanning electron microscopy. The tensile strength of the virgin hair was measured as $14.66\;g/cm^2$, tensile energy was $108\;erg/cm^2$, and the maximum stress was 146.64g. Those of the dyed hair were $13.69\;g/cm^2$, $89.62\;erg/cm^2$ and 136.90 g, respectively. The differences in the tensile strength, the tensile energy and the maximum stress were $-0.97\;g/cm^2$, $-18.38\;erg/cm^2$, -9.74 g, respectively, which showed that the dyed hair had less elasticity and strength than the virgin hair. In the scanning electron microscopy investigation of the damaged hair after the tensile test, lift-off of the cuticle outer layer were shown in both virgin hair and dyed hair, which was more severe in the dyed hair than the virgin hair. Adjacent cuticular cells of the cuticle layer were separated by the destruction of intercellular membrane complex. The macrofibrils were exposed and separated from the cortex torn by tensile strength.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.69-77
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• 2003

This study reviewed antioxidants and various enzymic physiological functions of Korean ash tree extractives that contains coumarine and ester component in order to examine the practical possibility of those materials as pharmaceutical and cosmetic additive applications. first, in the experiment of enzymic physiological activity, the electron donating ability showed 62.00% at 1ppm and over 90% at 10ppm or higher concentration, and the pseudo SOD ability showed 39% at the concentration of 2000ppm and 84.73% at the concentration of 5000ppm. Second, the inhibition activity of xanthine oxidase showed a relatively low inhibition effect of 45.57% at 200ppm, and the inhibition effect of tyrosinase showed 57.51% at 2000ppm. However, it showed a very low inhibition effect at the concentration of 500ppm or less. Third, the lipid oxidation, when Cu$\^$2＋/ion was used as an oxidation accelerator, showed the inhibition effect of 82% at the concentration of 10ppm, and when Fe$\^$2＋/ion was used also as the oxidation accelerator, it showed a very outstanding effect of 60% and more at 100ppm. Conclusively it is clear that the extracts of Korean ash tree bark can be used as cosmetic and pharmaceutical additive agents due to their excellent activities as antioxidant and enzymic physiological functions of it.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.8
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• pp.341-354
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• 2023

The title of a document is the brief summarization of the document. Readers can easily understand a document if we provide them with its title in their preferred styles and the languages. In this research, we propose a cross-lingual and style-based title generation model using multiple adapters. To train the model, we need a parallel corpus in several languages with different styles. It is quite difficult to construct this kind of parallel corpus; however, a monolingual title generation corpus of the same style can be built easily. Therefore, we apply a zero-shot strategy to generate a title in a different language and with a different style for an input document. A baseline model is Transformer consisting of an encoder and a decoder, pre-trained by several languages. The model is then equipped with multiple adapters for translation, languages, and styles. After the model learns a translation task from parallel corpus, it learns a title generation task from monolingual title generation corpus. When training the model with a task, we only activate an adapter that corresponds to the task. When generating a cross-lingual and style-based title, we only activate adapters that correspond to a target language and a target style. An experimental result shows that our proposed model is only as good as a pipeline model that first translates into a target language and then generates a title. There have been significant changes in natural language generation due to the emergence of large-scale language models. However, research to improve the performance of natural language generation using limited resources and limited data needs to continue. In this regard, this study seeks to explore the significance of such research.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.11
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• pp.481-492
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• 2023

This study explores how to build a Korean dataset to extract information from text using generative large language models. In modern society, mixed information circulates rapidly, and effectively categorizing and extracting it is crucial to the decision-making process. However, there is still a lack of Korean datasets for training. To overcome this, this study attempts to extract information using text-based zero-shot learning using a generative large language model to build a purposeful Korean dataset. In this study, the language model is instructed to output the desired result through prompt engineering in the form of "system"-"instruction"-"source input"-"output format", and the dataset is built by utilizing the in-context learning characteristics of the language model through input sentences. We validate our approach by comparing the generated dataset with the existing benchmark dataset, and achieve 25.47% higher performance compared to the KLUE-RoBERTa-large model for the relation information extraction task. The results of this study are expected to contribute to AI research by showing the feasibility of extracting knowledge elements from Korean text. Furthermore, this methodology can be utilized for various fields and purposes, and has potential for building various Korean datasets.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.7-17
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• 2005

The determination of seismic velocities in refractors for near-surface seismic refraction investigations is an ill-posed problem. Small variations in the computed time parameters can result in quite large lateral variations in the derived velocities, which are often artefacts of the inversion algorithms. Such artefacts are usually not recognized or corrected with forward modelling. Therefore, if detailed refractor models are sought with model based inversion, then detailed starting models are required. The usual source of artefacts in seismic velocities is irregular refractors. Under most circumstances, the variable migration of the generalized reciprocal method (GRM) is able to accommodate irregular interfaces and generate detailed starting models of the refractor. However, where the very-near-surface environment of the Earth is also irregular, the efficacy of the GRM is reduced, and weathering corrections can be necessary. Standard methods for correcting for surface irregularities are usually not practical where the very-near-surface irregularities are of limited lateral extent. In such circumstances, the GRM smoothing statics method (SSM) is a simple and robust approach, which can facilitate more-accurate estimates of refractor velocities. The GRM SSM generates a smoothing 'statics' correction by subtracting an average of the time-depths computed with a range of XY values from the time-depths computed with a zero XY value (where the XY value is the separation between the receivers used to compute the time-depth). The time-depths to the deeper target refractors do not vary greatly with varying XY values, and therefore an average is much the same as the optimum value. However, the time-depths for the very-near-surface irregularities migrate laterally with increasing XY values and they are substantially reduced with the averaging process. As a result, the time-depth profile averaged over a range of XY values is effectively corrected for the near-surface irregularities. In addition, the time-depths computed with a Bero XY value are the sum of both the near-surface effects and the time-depths to the target refractor. Therefore, their subtraction generates an approximate 'statics' correction, which in turn, is subtracted from the traveltimes The GRM SSM is essentially a smoothing procedure, rather than a deterministic weathering correction approach, and it is most effective with near-surface irregularities of quite limited lateral extent. Model and case studies demonstrate that the GRM SSM substantially improves the reliability in determining detailed seismic velocities in irregular refractors.

• Journal of Life Science
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• v.30 no.6
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• pp.532-541
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• 2020

In this study, we describe the inhibition of adipocyte differentiation by the lactic acid bacteria (LAB) fermentation product of Chrysanthemum indicum L. (CI) extract to control obesity. Preparation of LAB-fermented products was performed to overcome the cytotoxicity of CI extract. During fermentation and 3T3-L1 cell line experiment, cytotoxicity was not induced in the CI fermentation products over 1 day in culture. Fermented materials from highly proliferative cultures were selected for treatment of 3T3-L1 cells and for comparison with unfermented control groups. Cell survival and undifferentiated cell populations were decreased differentiation population in all experimental groups compared with controls, as measured using fluorescence-activated cell sorting analysis. Akt pathway activity increased upon treatment with these fermented extracts in 3T3-L1 cells. Gli2 depleted at the protein level in association with adipocyte differentiation. LAB KCTC 3115- and 3109-fermented extract treatment caused controlled Gli2 protein accumulation. Moreover, KCTC 3115 and 3109 were found to reduce C/EBPα and FAS was depleted, whereas pACC was increased at the protein level upon treatment with the fermentation products of each of the four LAB used in this study. With Lactococcus lactis subsp. lactis KCTC 3115 fermentation, the regulation of adipose differentiation and hedgehog signaling were also suppressed, thereby inhibiting the differentiation of progenitor cells. The basis for the activation of hedgehog signaling may provide insights into the treatment of obesity and the inhibition of adipocyte differentiation.