• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.445-450
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• 2019

Recently, consumers using cosmetics have a great interest in raw material safety. Among them, interest in natural preservatives is increasing, and as the demand for cosmetics excluding paraben preservatives increases, a method of replacing synthetic preservatives with antibacterial essential oils is being considered. The antibacterial effect of essential oils depends on the components, concentrations and interactions between the main active compounds. Effective preservatives should have antimicrobial activity against a wide range of strains even at minimal concentrations. All preservatives should be considered to increase skin concentration and cause skin irritation and allergic reactions. Consumers recognize that essential oils from nature are safe, but some should be careful because they can cause contact allergies or phototoxic reactions. As such, it is important to balance natural preservatives with maximum preservative effects and low toxicity. This paper describes the characteristics of essential oils focused on antibacterial properties, efficacy and safety as cosmetic preservatives.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.40-40
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• 2018

현실화된 기후변화로 인하여 강수패턴 및 강수량의 변화가 발생함에 따라 물 관리의 불확실성이 증가하고 있는 실정이며 또한 2014년부터 시작된 극심한 가뭄은 안정적인 용수공급에 많은 어려움을 주고 있다. 예로 보령댐의 경우 저수율이 2015년 19%, 2017년 8.3%로 역대 최저를 기록한 바 있고 2018년 3월 기준 운문댐과 밀양댐의 경우 저수율이 각각 11%(심각), 26.2%(경계)로 극심한 물부족에 시달리고 있다. 이러한 극심한 가뭄에 대응하기 위해서는 시설간 연계 운영, 급수체계 조정, 도수로 가동 등과 같은 구조적 대책과 더불어 저수용량에 따라 용수공급량을 감축하는 형태의 비구조적 대책의 일환인 용수공급 조정기준이 동시에 이루어져야 한다. 용수공급 조정기준은 국토교통부에서 주기적으로 발생하고 있는 가뭄에 대하여 대응하기 위해 만들어진 기준으로 다목적댐의 저수량을 기준으로 단계별(관심, 주의, 경계, 심각) 공급량을 감축하여 장기간 공급함으로써 국가재난을 사전에 예방하는 것을 목표로 하고 있다. 이러한 용수공급 조정기준을 수립하기 위해서는 최소 20년 이상의 과거 관측된 유입량 자료를 모의 발생하여 이수안전도 95%이상을 만족하는 단계별 용수공급 조정 기준선을 작성하게 된다. 하지만 신규 댐의 경우 관측된 유입량 자료가 전무함에 따라 용수공급 조정 기준을 수립하는데 어려움이 있다. 따라서 본 연구에서는 신뢰할 수 있는 유입량 자료를 생산하기 위해 첫 번째로 물리적 기반인 분포형 강우-유출 모형을 구축하고 검보정을 수행하였으며 이처럼 구축된 강우-유출모형을 이용하여 다수의 유입량 자료를 생산하였다. 두 번째로 SAMS 2007을 이용하여 유입량 자료를 모의 발생시켰으며 이를 저수지 운영에 활용하여 이수안전도 95%를 만족하는 용수공급 조정기준을 수립하였다. 본 연구의 결과는 극심한 가뭄에 대비하여 안정적인 용수공급 및 수자원 확보 등 이수적인 측면에서 크게 활용 가능할 것으로 판단된다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.3
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• pp.27-33
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• 2007

Recently, a new hard problem on a two dimensional vector space called vector decomposition problem (VDP) was proposed by M. Yoshida et al. and proved that it is at least as hard as the computational Diffe-Hellman problem (CDHP) on a one dimensional subspace under certain conditions. However, in this paper we present the VDP relative to a specific basis can be solved in polynomial time although the conditions proposed by M. Yoshida on the vector space are satisfied. We also suggest strong instances based on a certain type basis which make the VDP difficult for any random vector relative to the basis. Therefore, we need to choose the basis carefully so that the VDP can serve as the underlying intractable problem in the cryptographic protocols.

• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.233-236
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• 2021

Recently, the Justice Party is pushing for legislation of a bill called the Algorithm Transparency Act. The bill is a revision to the Information and Communication Network Act proposed by Rep. Ryu Ho-jung on June 25, 2021, and aims to form a separate committee under the Korea Communications Commission to ask organizations operated for profit to search algorithms and explain the principles of arrangement. Currently, Korea treats algorithms as corporate secrets and does not disclose them, while the European Union (EU) implements the Personal Information Protection Regulations (GDPR) in relation to algorithm regulations. Therefore, this study summarizes the main contents of the Algorithm Transparency Act currently proposed to the National Assembly and reviews the current status of algorithm-related laws and systems in the European Union (EU) and the improvement of algorithm transparency.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.80-80
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• 2021

2020년은 장마와 태풍으로 인해 중부 및 남부지방에 폭우가 발생하여 강남역을 비롯한 지하철 역사와 지하 주차장 등 많은 지하시설이 침수되었고, 부산에서는 침수된 지하차도에 진입한 차량의 운전자가 사망하는 등의 사고가 발생하였다. 지하에 설치된 시설들은 침수가 발생할 경우 대부분 출입구를 통해 유입되는 물을 거슬러 대피해야 하므로 낙상과 그로 인한 익사 등 자칫 큰 인명피해를 초래할 수 있어 특별히 주의할 필요가 있다. 대피 여부를 결정하고 그에 필요한 시간을 계산하기 위해서는 안전하게 대피 가능한 최대수심(한계수심)을 결정하는 것이 필요하다. 현재 한계수심을 제시한 여러 연구가 있지만 대부분 소수의 성인만을 대상으로 한 실험 결과이기 때문에 성별, 연령, 체중 등 다양한 유형의 사람을 고려한 대피방법 제시가 필요하다. 이에 본 연구에서는 실험 참가자의 유형(성별, 연령, 체중, 신장)에 따른 대피시간의 차이를 고려한 한계수심을 제시할 수 있도록 하였다. 총 308명이 실험에 참여하였으며, 이중 남성은 164명, 여성은 144명이었다. 참가자의 연령은 14세부터 75세까지이며, 신장은 최소 145cm에서 최대 187cm, 체중은 35kgf에서 110kgf 범위이다. 대피시간은 물이 흘러 내려오는 5.1m 길이의 계단을, 난간을 잡은 채 거슬러 올라가는 시간으로 설정하였으며, 계단 상층부의 수심이 30cm일 때와 40cm일 때(한계수심 조건), 2회 측정하였다. 또한, 측정이 종료된 후, '안전하게 대피 가능할 것으로 예상되는 수심'을 선택하도록 하여 참가자가 체감한 실험 난이도를 간접적으로 확인하고 향후 연구에 활용할 수 있도록 하였다. 수집된 자료를 분석한 결과 여성의 경우 수심 30cm와 40cm의 평균 대피시간이 4초 정도의 차이가 나타났으나, 남성의 경우 유의미한 차이가 나타나지 않았다. 또한 '안전하게 대피 가능할 것으로 예상되는 수심'에 대한 답변으로 다수가 실험의 최대 수심 조건인 40cm 이상을 선택하였다. 이와 같은 결과를 보아, 실험의 난도가 높지 않았다고 예상할 수 있으며, 그 원인은 참가자의 안전을 고려해 실험 조건을 난간을 잡은 채 보행하도록 설정한 것이 한계수심을 증가시키는 결과를 가져왔다고 볼 수 있다. 유형에 따른 대피시간의 차이를 분석하기 위해서는 실험의 한계수심 조건을 높이거나, 난간을 잡지 않고 보행할 수 있도록 안전장치를 추가하는 등, 실험조건의 변화가 필요할 것으로 판단되며, 추가적으로 난간을 잡은 채 보행하는 것이 한계수심을 얼마나 높일 수 있는지에 대한 검토를 통하여 정량적인 대피가능 시간을 제시할 수 있을 것으로 사료된다.

• 한국노년학
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• v.30 no.4
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• pp.1045-1058
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• 2010

Based on Rawl's Justice Theory, the author examines the rationales for educating older adults and advocates for their needs for just distributions of educational resources and opportunities. The author also seeks policy implications for establishing just educational systems for older citizens. On the basis of Rawl's Justice Theory, the essential principles for realizing social justice are presented. The author points out the Veil of Ignorance and Rational Indifference. As the practical methods for achieving social justice, the author presents Exclusion of Coincidence, Difference Principle, Democratic Equality, and Common Asset. Implications for establishing just education systems for older adults include: 1) The least advantaged groups such as older adults, females, and the disabled should not be discriminated in the distribution of educational resources; 2) People with higher capacities are obliged to serve less capable people; and 3) Older adults should mobilize all resources to empower themselves and to develop their potentials. The author concludes that Rawl's Justice Theory can be tapped into as a useful ideological framework in order to expand educational resources and opportunities for older adults.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.119-126
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• 1987

This study was conducted to elucidate the most appropriate method to obtain auxotrophic mutants from Valsa ceratosperma, the causal fungus of apple canker, which may be used as a gene marker in detecting the transfer of the factors of avirulent strains to virulent strains. Among the 3 kinds of synthetic media tested, each have two formula for minimal and complete, the medium which has been used in study of Endothia parasitica (E. P medium) was turned out to be most appropriate for the growth of V. ceratosperma. A medium for single colony formation from pycnidiospore of this fungus was developed by adding 0.5% L - sorbose to the E. P minimal medium. The period of incubation in dark for preventing the photoreactivation after U. V irradiation was estimated as about 60hrs at which most of the spores become binucleate. Largest number of putative auxotrophs were obtained at about 50second of irradiation to the spores smeared on the medium for single colony formation, at which the survival rate of spores was 5 to 6 percent. With these method developed in this experiment, 161 isolates of putative auxotrophs were detected among which the nutrient requirement for 10 isolates were determined. Five out of 10 mutants were still virulent to apple tree and all but one could not sporulate.

• Journal of Korean Home Economics Education Association
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• v.21 no.3
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• pp.45-64
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• 2009

The purpose of this study was to develope issue-centered teaching learning process plan for environment-friendly housing education and to apply it to the housing section of Technology Home Economics in a middle school. PRO-CON cooperative group model was used for the teaching learning process plans of 2-session lessons according to the ADDIE model. In the development stage, 7 activity materials and 20 teaching learning materials (4 reading texts, 12 pictures and photos, & 5 moving pictures) were developed for 2-session lessons. The plans applied to the 7 classes, 222 students, in the third grade of the G middle school in Gyeonggi-do during July 10th-17th, 2008. The results showed that the final pro-con was influenced by the rationals of juries' pro-con of each team and the representative's discussion besides one's environmental perspective. The intention to implement environment-friendly housing activities was significantly increased between before and after the lessons. The contents, methods, goals, and process of the 2-session lessons were evaluated over medium to somewhat higher levels. Those evaluations except methods and general satisfaction with the lessons were differed by sex, students' and their families' interests in environments but not by the type of housing. These results might support that pro-con cooperative group model of controversial issues on parking lot would be appropriate to environment-friendly housing lessons and could apply to broad issues on housing and various schools in other areas.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.19-30
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• 2000

LaF, KzFS1, LBO glass were manufactured successfully by using platinum crucible in LaF and using clay crucible in the KzFS1 and LBO. There was optically transparent and the refractive indexes were measured by minum deviation method of prism. LaF, KzFS1, LBO show that the refrective indexes are $n_d$ = 1.770 in LaF, $n_d$ = 1.603 in KzFS1, $n_d$ = 1.560 in LBO. The transmittance were obtained that LaF has 85%, and KzFS1 has 83% and LBO has 89% in visible range. These glasses have no any absorption spectrum under visible range. Therefore it has no any color.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.146-156
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• 2016

In this study, we developed a large fire forecasting system using critical weather conditions, such as strong winds and effective humidity. We incorporated information on forest type prior to large fires using an incident case study. The case study includes thirty-seven large fires covering more than 100 ha of damaged area over the last 20 years. Dangerous large fire regions were identified as areas of more than 30 ha of Korean red pine and the surrounding two kilometers. Large fires occur when wind speeds average 5.3 m/s with a maximum of 11.6 m/s and standard deviation of 2.5 m/s. Effective humidity for large fires average 30% with a minimum of 13% and standard deviation of 14.5%. In dangerous Korean red pine stand areas, the large fire 'Watch' level is issued when effective humidity is 30-45% for more than two days and average wind speed is 7-10 m/s. The 'Warning' level is issued when effective humidity is less than 30% for more than two days and average wind speed is more than 11 m/s. Therefore, from now on, the large fire forecasting system can be used effectively for forest fire prevention activities based on a selection and concentration strategy in dangerous large fire regions using severe weather conditions.