• Current Industrial and Technological Trends in Aerospace
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• v.6 no.2
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• pp.60-68
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• 2008

The characteristic and properties of materials are rapidly degraded when subjected to the synergistic effects of the space environment such as atomic oxygen, radiation, vacuum and thermal cycling. In order to understand the mechanism of material property variation in space environment and to develop new space materials applicable to the future space program, advanced space organizations such as NASA, ESA and JAXA have been continuing many researches on material test specimens used on ISSE(International Space Station Experiment) or LDEF(Long Duration Exposure Facility). In this paper, the selection requirements and verification trend of materials in space applications

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.75-88
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• 2011

Messages need to transmit to the neighbors securely in wireless sensor network, because a sensor node is deployed in hostile area. Thus it is necessary to support secure communication. One of the most important communication part is secure multicast. Especially, group rekeying is a big problem for multicast key management. So, group rekeying must be proceed securely when secrete information is exposed by attacker. Many group rekeying schemes have been studied for ad hoc networks. However, these schemes are Ill1desirable in WSNs. In this paper, we proposed a novel group rekeying scheme in WSNs that it has very powerful security.

• Analytical Science and Technology
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• v.20 no.2
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• pp.91-108
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• 2007

This study was investigated both the Korean official soil test method and the international various methods for PCBs in soil sample. The analytical guideline of PCBs in contaminated soil were proposed based on the official soil test methods by discussing the extraction, column cleanup, instrumental conditions, quantification methods of peak matching and individual isomers. The total 28 soil samples were selected by consideration of PCBs-contamination, land use etc., and then analyzed using gas chromatography/electron capture detection (GC/ECD) and gas chromatography/mass spectrometry(GC/MS). In this study, the PCBs were not detected as peak matching method using GC/ECD, but PCBs detected $0.002{\sim}0.487{\mu}g/kg$ using GC/MS in background concentrations.

• Korean journal of applied entomology
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• v.49 no.1
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• pp.23-29
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• 2010

The environmental risks of cucumber mosaic virus resistant transgenic chili peppers with the CMVP0-CP gene on non-target organisms in the agroecosystem environments was evaluated during the periods of the chili pepper growing season (June 19, July 30, August 31) in 2007. Arthropods assemblages leaves and flowers of chili peppers were quantitatively collected by using an insect vacuum collector to compare the arthropod community structures between non-transgenic chili peppers (nTR, P 915) and mosaic virus resistant transgenic chili peppers (TR, CMV-cp, line 7). There was no statistical difference in the arthropod community structure between the two types of crops, nTR and TR, at the same season, although the species richness and Shannon's index were somewhat different among seasons; indicating no effects of genetically modified peppers on the arthropod community. However, further studies were required to conclude more concretely for the potential environmental risk of the transgenic chili pepper of CMV-cp.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.232-239
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• 2018

Our study aims to provide a guideline of deer-proof fence heights to prevent roadkill of water deer (Hydropotes inermis), the most frequently killed by a vehicle collision, in South Korea. With 27 water deer in deer ecology center of the National Institute of Ecology, we measured the ability of water deer to jump gradually higher fences from 0.5cm by 10cm until the deterrence rate reached 100%. Ourresultrevealed that the deterrence rate became 96.7% at the fence height of 1.5m and the rate reached 100% at the 1.8m. We believe that our result provides the fundamental information to prepare a standard of deer-proof fence height. This evidence-based standard will contribute to improving the guideline for wildlife crossing construction and management, established by Ministry of Environment Korea.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.322-328
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• 2012

To estimate the population size of Miho spine roach (Cobitis choii), one of national monument species in Korea, multiple mark-recapture experiments (Jolly-Seber model) by VIE tagging were conducted in the upper region of the Backgok Stream located in the Kum-River system, Korea. Fish sampling was conducted at four different times from October 5 to October 26, 2011. A total of 335 sampling points were sampled, where the species was determined in 217. The population size was estimated to be 6,143 in this study. Compared to a previous report conducted by the Korean Ministry of Environment (2009), the population size of this species has decreased by 41%. The reasons for population decline are thought to be due to loss of microhabitat, sedimentation, water pollution. Consequently, a habitat restoration program is required to protect the microhabitat and recover the population size in this area.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.69-76
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• 2021

This study is to identify the mineralogical properties of caprock samples from drilling cores of the Pohang basin, which is the research area for the demonstration-scale CO2 storage project in Korea. The interaction of water-rock-gas that can occur due to CO2 injection was identified using geochemical modeling. Results of mineralogical studies, together with petrographic data of caprock and data on the physicochemical parameters of pore water were used for geochemical modeling. Modelling was carried out using the The Geochemist's Workbench 14.0.1 geochemical simulator. Two steps of modeling enabled prediction of immediate changes in the caprocks impacted by the first stage of CO2 injection and the assessment of long-term effects of sequestration. Results of minerlaogical analysis showed that the caprock samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, kaolinite and montmollonite. After the injection of carbon dioxide, the porosity of the caprock increased due to the dissolution of calcite, and dawsonite and chalcedony were precipitated as a result of the dissolution of albite and k-feldspar. In the second step after the injection was completed, the precipitation of dawsonite and chalcedony occurred as a result of dissolution of calcite and albite, and the pH was increased due to this reaction. Results of these studies are expected to be used as data to quantitatively evaluate the efficiency of mineral trapping capture in long-term storage of carbon dioxide.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.308-311
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• 2007

대부분의 센서 네트워크에서 센서 노드들은 열린 환경에서 독립적으로 동작하므로 보안 공격에 취약하다. 허위 보고서 삽입 공격에서 공격자는 허위 경보를 발생시키거나 혹은 네트워크 내 에너지의 고갈을 목적으로 포획된 노드들을 통해 허위 보고서를 네트워크에 삽입한다. 이러한 허위 보고서를 조기에 검출, 제거하기 위해 많은 여과 기법들이 제안되었다. 가환 암호 기반 여과 기법에서 각각의 중간 노드는 확률에 기반 하여 보고서 인증을 수행한다. 따라서 허위 보고서가 여과되지 않거나 정상 보고서가 여러 번 인증 받을 가능성이 있다. 또한 네트워크의 상태 변화에 적응하기 어렵다. 본 논문은 퍼지 논리를 이용한 무선 센서 네트워크에서의 임계값 기반 여과 기법을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.756-758
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• 1999

본 논문에서는 최적의 성능을 갖는 병렬 프로그램을 개발하는데 필수 도구인 성능가시화기를 이식성, 확장성 그리고 효율성을 고려해 설계 및 구현한 PnP 스타일의 성능 가시화기에 대하여 기술한다. 본 가시화기는 기존 가시화기의 문제점인 수정 및 변용에의 어려움을 해결하기 위하여 독립된 계층구조인 인스트루멘테이션층, 인터페이스층, 가시화층으로 구성함으로써 확장성 및 이식성을 갖도록 하였다. 인스트루멘테이션층은 사건(event)을 포획하기 위해 개발된 라이브러리인 ECL(Event Capture Library)로 구성되며, 인터페이스층은 인스트루멘테이션층과 가시화층간에 확장성 있는 문제중심 인터페이스를 제공하기 위해 개발된 사건 기술 언어 및 Java 문제중심 엑세스 라이브러리로 구성되었다. 그리고 PnP 스타일의 성능 가시화기를 설계함으로써 뷰와 필터의 추가 및 수정이 용이하도록 가시화층을 구현하였다. 이렇게 구현된 성능가시화기는 독립된 도구로 사용될 수 있을 뿐 아니라 병렬 프로그래밍, 디버깅, 그리고 성능 분석이 통합된 프로그램 개발환경 구축의 핵심도구로서 활용될 수 있을 것이다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.507-508
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• 2018

본 논문에서는 라즈베리파이를 활용하여 야생조류의 행동에 반응하는 비전기반 야생조류 퇴치 장치를 구현하였다. 저가형 라즈베리파이 보드를 기반으로 카메라센서와 OpenCV 모션탐지기법을 활용하여 야생조류의 침입을 탐지하고, 그리고 야생조류가 소리별로 반응하는 데이터를 누적시키는 방법을 활용하여 효율적으로 퇴치하도록 개발하였다. 성능평가는 야생 직박구리와 박새를 포획하여 야외 실험장에서 진행하였고 실제 환경에서도 야생조류를 퇴치할 수 있다는 결과를 보여준다.