• Title/Summary/Keyword: 유기자원

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개불, Urechis unicinctus의 난발생 및 유생사육에 미치는 수온의 영향

  • 강경호;김재민;양호철
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.247-248
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    • 2000
  • 개불류는 연안의 사니질에서 쉽게 발견되며 그 종류의 수나 자원량이 풍부한 저서동물군이다. 이들은 번식력이 강하고 저질에 U자형의 굴을 뚫어 해수를 순환하게 함으로써 유기성분을 변화시켜 저질을 정화시키기도 하는 등, 연안생태계에서 매우 중요한 위치를 점하고 있다. 개불의 양식기술을 개발하기 위해서는 우선적으로 어미의 확보 및 산란유발, 난발생 및 유생사육 등에 관한 생물학적인 기초자료가 필요하게 된다. (중략)

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An analysis of HFC for Wired and Wireless Networks (유.무선 통합을 위한 HFC(Hybrid Fiber Coaxial)망 분석)

  • 이성구;이병욱;조성호
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10c
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    • pp.349-351
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    • 2003
  • 최근 유선 및 무선통신의 응용서비스와 제공기반을 유기적으로 결합한 서비스를 이용하려는 욕구가 증가하고 있으며 제공 기능의 통합에 따른 단일 패키지 형태의 서비스 전개가 요구되고 있다. 이를 위해서는 유무선 통신망 자원의 공유 및 상호 의존도를 높여 통신망 상호간 재활용성 및 운용비용의 절감을 유도하는 통신망 구축의 필요성이 대두되고 있다. 본 논문에서는 향후 2~3년 내에 보급이 활성화 될 것으로 예측되는 유무선 통합망을 케이블망에 적용했을 경우에 대해 분석해 본다.

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Detecting scheme against bypass Denial of Service Attack (우회 DoS 공격을 탐지하기 위한 모델 설계)

  • 김용석;전준철;유기영
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10a
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    • pp.709-711
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    • 2003
  • 현재 사용되어지는 컴퓨터 통신 프로토콜(OSI 7 layer reference model)은 구조적인 문제점을 들어내고 있다. 이런 문제점 때문에, 해커들은 수많은 패킷들을 생성시키는 Denial of Service(DoS) 공격과 Distributed Denial of Service(DDoS) 공격을 사용하여 한 호스트나 한 네트워크 자원에 치명적인 악영향을 미친다. 특정한 TCP 포트나 UDP 포트에 공격을 가하는 경우에는 룰 기반의 침입탐지 시스템(IDS)이 탐지 해낼 수 있지만 다른 임의의 포트에 공격을 가하게 되연 IDS는 이것을 탐지하지 못한다. 따라서 우리는 잉의의 포트에 DoS나 DDoS 공격들이 일어났을 때 이 공격들을 탐지할 수 있는 모델을 설계하였다.

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Activation method for biogas production from organic waste (긴급제언: 유기성폐기물 자원(바이오가스 생산) 활성화 방안)

  • Kwak, Che-Sik
    • Journal of the Korean Professional Engineers Association
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    • v.43 no.5
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    • pp.35-40
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    • 2010
  • The world economy is threatened by rising oil prices due to the depletion of resources, and climatic changes are intensified due to rapid increase of greenhouse gases emission. Global warming is recognized as a worldwide problem not only as national level one, collaborative efforts are in progress actively. The fact is that the development of new & renewable energy which can replace fossil fuel and preserve the environment is the key of the attention in accordance with "low carbon, green growth" policy of our government. Biogas is an energy source. And the best part of using biogas is that wastes are treated in its production process.

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개불, Urechis unicinctus 유생의 수온과 염분 내성

  • 강경호;김재민
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.620-621
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    • 2001
  • 개불류는 연안의 사니질에서 쉽게 발견되며 그 종류의 수나 자원량이 풍부한 저서 동물군이다. 이들은 번식력이 강하고 저질에 U자형의 굴을 들어 해수를 순환하게 함으로써 유기성분을 변화시켜 저질을 정화시키기도 하는 등, 연안생태계에서 매우 중요한 위치를 점하고 있다. 개불의 양식기술을 개발하기 위해서는 우선적으로 어미의 확보 및 산란유발, 난발생 및 유생사육 등에 관한 생물학적인 기초자료가 필요하게 된다. (중략)

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Basic study on the biological and physicochemical properties of burnt forest soil for the ecological restoration by organic waste (유기성폐자원을 이용한 산불토양의 생태학적 복원을 위한 토양의 생물학적, 물리화학적 기초특성연구)

  • Jung, Young-Ryul;Song, In-Geun;Kim, Young-Jun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.13 no.1
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    • pp.79-89
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    • 2005
  • Forest soils were analyzed on their biological and physicochemical properties for the ecological restoration of burnt forest soil using organic wastes and proper microorganisms. Three kinds of soil samples were collected from undamaged soil(US), naturally restoring soil(NS) and artificially restoring soil(AS). All soil samples were sandy soil and acidic soil, ranged pH 5.34~5.78. Moisture content was higher in the soil of NS region. And the others were similar. Total organic matter and soluble sugar were higher at the surface, generally. Heterotrophic soil microbes were abundant at the surface soil of NS and subsoil of AS. Dehydrogenase, cellulase and phosphatase activities were higher at the NS soil. Especially, Dehydrogenase activity as primary index of soil microbial process showed high correlationship with moisture content(r=0.90, P < 0.05).

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Deicing Performance of Environment-friendly Deicing Agents (친환경 제설제인 CMO의 성능평가 분석)

  • Lee, Seung-Woo;Woo, Chang-Wan;Kim, Jong-Oh;Park, Hee-Mun
    • International Journal of Highway Engineering
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    • v.7 no.3 s.25
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    • pp.53-62
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    • 2005
  • Efficient snow-removing work is one of important processes of winter road management. Calcium chloride has been used as a typical deicing agent in Korea. It presents superial performance as snow deicing agents, however it has been known to give serious environmental problem and to deteriorate durability of concrete structure in road by corrosion. The environment-friendly road deicing agents made from the waste material which is liquid phase organic matter that is Ca Mg and reactant of organic acid (nitric acid and propionic acid) have been introduced by number of researchers. They indicated the calcium magnesium salt of organic acids have advantage over the calcium choride in terms of lower production unit cost by resources recycling and can solve environmental problem and durability deterioration of structures. In this study, the deicing performance of calcium magnesium salt of organic acids(CMO) is investigated based on the series of experiments including the test for heat of dissolution, freezing point, ice melting test and ice penetration test.

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Recovery and Characterization of Lactic Acid from Fermentation Broth Using Chemical Precipitation (화학침전을 이용한 발효액의 젖산 회수 및 유기물 특성분석)

  • Lee, Wontae
    • Journal of the Korea Organic Resources Recycling Association
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    • v.26 no.1
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    • pp.47-53
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    • 2018
  • Recovery of lactic acid from fermentation broth using chemical precipitation was investigated with various chemicals. Effects of chemical types, mixing speeds, settling duration, and solvent addition were evaluated to improve the recovery rates of lactic acid. Overall, recovery efficiencies increased as the dosage of chemicals increased. Recovery rate of lactic acid by CaO was higher than those of $Ca(OH)_2$ and $CaCO_3$. Recovery of lactic acid increased by 48% under the optimized reaction conditions which included a mixing speed at 180 rpm, a settling duration of 24 h, and addition of ethanol at 25%(v/v). Practical application needs to consider types and concentrations of other organic acids as well as lactic acid. Based upon the results of fluorescence excitation emission matrix (FEEM), size exclusion chromatography (SEC), characteristics of recovered lactic acid were same as that in the fermentation broth.