• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.675-678
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• 2017

본 논문에서는 스트림 환경에서의 샘플링 기법 중 랜덤 샘플링과 유사한 특성을 갖는 KSample의 균일신뢰도 향상에 초점을 맞춘다. 이를 위해, 먼저 KSample의 균일신뢰도 문제점을 분석하여 KSample의 균일신뢰도가 초기에 많이 감소하는 현상을 초기 균일신뢰도 저하 문제로, KSample의 균일신뢰도가 지속적으로 감소하는 현상을 지속 균일신뢰도 저하 문제라 정의한다. 그리고 초기 균일신뢰도 저하 문제를 발생시키는 성질을 과거 샘플 불변으로, 지속 균일신뢰도 저하 문제를 발생시키는 성질을 샘플 추출 범위 증가로 정의하고 이를 해결하여 균일신뢰도를 향상시킨 UC KSample을 제안한다. 실험 결과, 샘플링 비율 p=0.01, 균일신뢰도 하한 ${\varepsilon}=0.7$일 때, UC KSample의 균일신뢰도가 기존 KSample 보다 약 2.2배 증가하였고, 균일신뢰도는 항상 하한 이상으로 유지되었다. 본 연구는 스트림 환경에서 중요한 척도인 균일신뢰도를 KSample에 결합시킨 최초의 시도로서, 샘플링 비율을 유지하며 동적으로 샘플링하는 KSample의 장점은 유지하면서도 균일신뢰도를 증가시킨 우수한 연구라 사료된다.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.3
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• pp.140-148
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• 2017

The effectiveness of the first flush treatment system using settling process was evaluated to reduce urban nonpoint source pollutant loads to surface water during storm events. A pilot scale system was constructed and tested in the field and surface runoff samples were collected automatically according to pre-defined conditions. Nine rainfall events were tested and average removal efficiencies of TSS (Total Suspended Solid), TP (Total Phosphorus) and TN (Total Nitrogen) were evaluated as 87.4%, 75.3%, and 43.6%, respectively. Concentration and removal efficiency of pollutants were found to be affected by an amount of rainfall and rainfall intensities of the respective events. This seemed to be caused by the greater particulate fractions of first flushed samples than the samples collected in later time periods during the same rainfall events. The study showed that it is possible to remove a significant portion of the nonpoint source pollutant loads in initial rainfall runoff by using a simple settling process for TSS and TP without requiring additional power or chemicals.

• Journal of Life Science
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• v.13 no.4
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• pp.511-515
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• 2003

White rot fungi, Phanerochaete sp. EJ-31L, was evaluated for its ability to decolorize Remazol Black B, an azo dye that is a widespread pollutant in the wastewater of textile industry. It was observed that extent of decolorization by Phanerochaete sp. EJ-31L was dependent on the concentrations of co-carbon and nitrogen source. Effects of agitation and aeration were studied, and agitated culture at aeration condition resulted in greater extent of decolorization than static culture. Remazol Black B was readily decolorized up to 95% within 64 hr by Phanerochaete sp. EJ-31L.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.247-255
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• 2016

Non-point pollutants from surface runoff during rainfall exert adverse effects on urban river water quality management. In particular, the first flush effect during the initial phase of rainfall can deliver significant amounts of pollutant loads to surface waters with extremely high concentrations. In this study, a sustainable first flush effect management system was developed by using settling and filtration that require no additional power or chemicals. A pilot scale experiment has shown that the removal of total suspended solid (TSS), total nitrogen (TN) and total phosphorus (TP) are in ranges of 84 - 95%, 31 - 46%, and 42 - 86%, respectively. An Integrated Stormwater Runoff Management System (ISTORMS) was also developed to efficiently manage the developed system by linking weather forecast, flow rate and water quality modeling of surface runoff and automatic monitoring systems in fields and in the system. This study can provide effective solutions for the management of urban river in terms of both quantity and quality.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.250-251
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• 2015

본 논문에서는 자기 조직화 기능을 갖는 Kohonen의 SOM(Self organization map) 신경회로망과 주어지는 데이터에 따라 초기의 클러스터 개수를 설정하여 처리하는 수정된 K-Means 알고리즘을 결합한 Hybrid Kohonen Network 를 제안한다. 또한, 실제의 항공영상에 적용하여 고전적인 K-Means 알고리즘 및 고전적인 SOM 알고리즘보다 우수함을 보인다.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1511-1517
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• 1999

Effects of washing methods using electrolyzed acid water on lettuce(Lactuca sativa) and quality changes during storage were investigated. The multi-stage immersion treated 3 times in 2 min showed more effective than others to remove microorganisms. Total count of lettuce after immersion in electrolyzed acid water was decreased to 1/100-1/300 of $5.8\;{\times}\;l0^5CFU/g$ of non-immersed lettuce and $2.3\;{\times}\;l0^5CFU/g$ of tap water immersed lettuce. Also coliforms was significantly decreased to 1/3,000 of $3.1\;{\times}\;10^3CFU/g$ after electrolyzed acid water washing. However, microbial levels of electrolyzed acid water treated one became to be similar to those of non-treated lettuce after 3 days of storage at $10^{\circ}C$. The color values of L and b of lettuce treated with electrolyzed acid water were somewhat higher than those of others. Though chlorophyll content of lettuce just after immersion in electrolyzed acid water was 9% lower than those of non-treated one, the content was decreased to the same level of other treatments during storage. Decaying ratio showed the lowest value in lettuce immersed in electrolyzed acid water until 6 days of storage. The sensory tests for overall acceptability and appearance of lettuce immersed in electrolyzed acid water showed higher than those of others until $3{\sim}6$ days of storage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.3
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• pp.216-220
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• 2002

In this study, edible coatings for ‘Niikata’ pears have been applied in order to provide an alternative way to control and extend market quality and shelf life during cold storage. Fruit treated with edible coatings had better effects on maintaining some quality features such as fresh weight, firmness and SSC content than non-coated fruits. However, non-coated fruits in terms of overall quality were better evaluated than fruit with edible film. It may be caused by various factors such as film thickness effect oil emulsion on fruit skin, unknown reactions between the fruit skin and functional groups in the chitosan structure and so on.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.335-340
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• 2013

This research was conducted to know the appropriate leaf number of scion for tube grafting in context with survival rate and quality of seedlings, and early yield of $1^{st}$ and $2^{nd}$ cluster of cherry tomato plants. Scions were grafted when having leaves 1~2 (LF-2), 2~3 (LF-3), or 3~4 (LF-4). The treatment LF-3 showed the highest survival rates and the best results in 6 factors among 12 seedling quality factors. In case of early yield, the treatment LF-2 showed higher yield than others with the big difference. Economic analysis showed that LF-3 is desirable in case of nursery while LF-2 is better in case of farmers. The compromising solution is that farmers buy a little expensive seedlings grafted at the leaf stage of 1~2 from nurseries in terms of win/win strategy.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.322-327
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• 2013

This research was conducted to elucidate the appropriate light environment right after grafting to produce vigorous cherry tomato seedlings. Tomato plants were grafted and then treated in 4 different ways: to keep in the natural light (Non), to cover the grafted stem part with aluminum foil to make only that part dark (Part), to put the grafted seedlings in the acclimation room for two (Day-2) or four days (Day-4) to make the whole seedlings in the dark condition. Tube grafting method was used for grafting, in which silicon tube of 1.5mm in diameter was used. The survival rate was the maximum in the treatment Day-2. The SPAD value, seedling quality and yield of $1^{st}$ and $2^{nd}$ cluster were the best in the treatment Part. The treatment Part needs cost more than other treatments but is more economic thanks to higher yield. Therefore it was concluded to be economically feasible to make the grafted stem part dark right after grafting in case of cherry tomato.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.55-58
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• 2001

기존에 MPEG-1, 2나 H.261/263 등에 사용되고있는 움직임 예측 방법은 블록 기반의 코딩 방식으로 단순히 영상의 움직임을 선형 모델로 간주하고 영상을 일정한 크기의 사각형으로 나누어, 각 사각형이 어느 곳으로 이동하는지를 추정하는 방식이었다. 그러나 이러한 방식은 블록 당 하나의 움직임 벡터만으로 처리하기 때문에 블록 내의 복잡한 움직임은 추정할 수 없을 뿐만 아니라, 보다 일반적인 움직임인 회전, 뒤틀림, 확대, 축소 등을 추정할 수 없다. 또한, 영상의 내용에 상관없이 일정한 크기의 블록으로 나누어 처리하기 때문에 주어진 영상에 최적화된 움직임 추정을 수행하기가 어렵다. 특히 저속 비트율에서는 이러한 점들이 크게 부각된다. 이러한 점들을 극복하기 위해서 여기에서는 삼각형 메쉬를 이용한 공간 변환 방법을 이용하였다. 여기에 영상을 영상에 따라 적응적으로 분해하여 처리할 수 있는 웨이브렛 패킷 부호화를 사용하여 에너지가 많고 적음에 따라 초기 제어점의 격자를 조절하여 좀 더 우수한 성능을 얻을 수 있다.