• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.212-214
• /
• 2000

The distance relay technique used for transmission line protection operates overreach and underreach to the self protection region because the power system becomes complex and fault conditions are different. To solve these problems, this paper describes new technique to set the reliable self protection lesion. The trip region of the quadrilateral distance relay is set by training of multi layer recurrent elman network. The proposed network is able to reach the trip zone for the fault impedance, fault initial angle and source impedance variance correctly.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.11a
• /
• pp.168-170
• /
• 2014

SDN(Software Defined Networking)은 프로그래밍을 통해 네트워크 경로 설정과 제어 및 기존에 복잡했던 운용관리를 처리할 수 있게 해주는 기술이다. 하지만 중앙 집중 식으로 관리하는 특성에 따라 병목현상이 발생할 수 있으며, 이는 컨트롤러에 트래픽이 집중되고 제어 명령을 지연시키는 문제가 있다. 본 논문은 이러한 문제점을 개선하고자 확장성 있는 메시지 플로우 제어 메커니즘을 제안한다. 이 방법은 기존 스위치와 다르게 목적지만을 저장하는 Table 을 별도로 관리하여 동일한 목적지로 전송되는 패킷에 대해 반복되는 제어 메시지를 감소시킨다. 이를 통해 컨트롤러의 역할을 스위치로 분산하여 Control Plane 트래픽에 대한 부하를 줄일 수 있고, 패킷 전송 Delay, Flow Setup 동안 발생하는 Latency 의 문제점을 효율적으로 개선 할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.11a
• /
• pp.715-716
• /
• 2009

인터넷의 발전은 대량의 정보를 양산하였고, 이러한 대량의 정보 집합 내에서는 비슷한 정보가 재활용 되거나 반복되는 정보중복문제를 가지고 있다. 중복되는 정보들로부터 사용자에게 원하는 정보를 신속히 검색할 수 있도록 하는 정보 요약에 대한 필요성은 점차 증가하고 있다. 본 논문은 비음수 행렬 인수분해(NMF, non-negative matrix factorization)에 의한 문서의 의미특징을 이용하여 주제기반의 다중문서를 요약하는 새로운 방법을 제안한다. 본 논문에서는 다중문서가 포함하고 있는 문서들 간의 고유구조를 문서요약에 이용하여서 요약의 질을 높일 수 있고, 주제와 문장 간의 유사성과 다양성 고려하여서 쉽게 과잉정보를 제거하여 문장을 요약할 수 있는 장점을 갖는다.

• The Journal of the Petrological Society of Korea
• /
• v.19 no.1
• /
• pp.51-65
• /
• 2010

The Dongmakgol Tuff is a stratigraphic unit which is composed of voluminous ignimbrites in the Cheolwon basin. The ignimbrites belong to pumice-rich vitric tuffs that show eutaxitic to parataxitic fabrics from fiamme or pumice clasts. They are almost densely welded and strongly flattened, but often parallel aligned and stretched. Also they exhibit flow indicators such as flow lineations, imbrications, tensional cracks and boudins from their alignment and/or elongation, and lithic and pumice clasts show lateral grading in their average maximum diameter. Flow direction map from the lineations, asymmetric structures and lateral grading diagram indicate that the Dongmakgol Tuff has a source from its southwestern part near a boundary between southern Dongmakri and northern Gomunri, and is considered that the ignimbrites took emplacement processes of laminar flows during the final stage of flowage and the flow lineations are from the result of shear stress during that times.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.9 no.5
• /
• pp.516-520
• /
• 1999

Mechanical alloying (MA) by planetary type ball mill of pure iron powders was carried out under the ammonia gas atmosphere. The powders of metastable iron nitrides was synthesized up to the nitrogen content of 23 at% N. The observed phases are identified as the super-saturated bcc solid solution for the nitrogen concentration below 14.5 at% N and the non-equilibrium hcp phase stable at high temperature for 20.8 at.% N. Magnetization of Fe-N powders gradually decreases with increasing the N concentration on contrast to the enhancement reported for the bct iron nitrides. Neutron diffraction experiments also provide detailed information concerning the local atomic structure surrounding the nitrogen atoms. The coordination number of Fe atom around a nitrogen atom for the iron nitride containing 9.5 at% N turns out to be 3.9 atoms. This suggests that a nitrogen atom is situated at a center of the tetrahedron formed by iron atoms.

• Journal of Korean Society of Forest Science
• /
• v.96 no.4
• /
• pp.432-437
• /
• 2007

The purpose of this study was to select regional distinctive Non-Timber Forest Products (NTFP) in Gangwon Inland Mountains Area. It was considered as NTFP Pine mushroom, Raw Oak Mushroom, Chestnut, Pinenut, Acorn, Resin, Cultivated Mountain Ginseng, Fernbrake, Chinese bellflower, Lance asiabell, Angelica, Aster scaber, Sap, Wood Vinegar. Regional weight, item weight and forest products quotient were used for the selection of NTFP. Forest products quotient was an application of Location Quotient that is used Input-Output analysis. As a result, Chestnut was selected in Chuncheon. Raw Oak Mushroom was selected in Wonju and Pyeongchang. It was selected Pinenut in Hongcheon, Lance asiabell in Hoengseong and Hwacheon, Acorn in Cheorwon, Aster scaber in Yanggu and Sap in Inje.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.04a
• /
• pp.425-428
• /
• 2001

알려지지 않은 악성 코드의 수행을 막는 방법으로 프로그램의 실행 환경을 제한하는 '샌드박스' 기법이 많이 쓰여져 왔다. 코드의 비정상 행위를 탐지하는 이 방식은 얼마나 다양한 샌드박스들을 두는가에 따라 적용성(configurability)과 편리성(ease of use) 간의 양면성 (trade-off)을 가진다. 기존의 MAPbox는 이 두 가지를 동시에 만족시키기 위해 프로그램의 종류별로 샌드박스를 두는 클래스별 샌드박스 적용 기법을 사용한다[3]. 그러나, 이 방법은 정적으로 클래스들이 결정되므로 적용성에 한계가 있다. 본 논문에서는 MAPbox의 개념에 동적 클래스 생성 기능을 추가함으로써 적용성을 높이는 기법을 소개하고 실제로 구현한다. MAPbox에 비해 적용성이 높아진 예로 MAPbox에서는 정상행위이지만 비정상행위로 판단되는 경우가 제안된 기법을 통해 올바르게 판단됨을 보인다.

• Aerospace Engineering and Technology
• /
• v.10 no.1
• /
• pp.39-44
• /
• 2011

A system of measurement for the thermal diffusivity of porous materials was developed. Although there are several measurement systems for thermal diffusivity, it is typically difficult to measure the thermal diffusivity of porous materials. This paper presents a measurement system for thermal diffusivity that utilizes a cyclic heating method along with the verification of the measured device. To verify the cyclic heating method, the available reference data of aceramic specimen was utilized. To apply the system to an actual porous material, polystyrene foam was tested. The thermal diffusivity of the polystyrene foam under vacuum was reduced by 63%. The measured values from both tests were in good agreement with the reference values, as they were within 10% of these values.

• Applied Biological Chemistry
• /
• v.40 no.1
• /
• pp.30-33
• /
• 1997

About 250 bp ura5 gene (Orotate phosphoribosyl transferase) fragment was cloned from genomic DNA of entomopathogenic fungus Metarhizium anisopliae by using PCR method. Entire nucleotide sequences of cloned DNA fragment were determined and analysed as compared with other fungus ura5 genes. The amino acid sequence deduced from the nucleotide sequence showed 85.5% homology to ura5 protein of Trichoderma reesei. Using this 250 bp PCR fragment we have isolated full ura5 gene of M. anisopliae by genomic Southern hybridization and the isolated 4.4 kb DNA fragments were mapped by restrictional enzyme.

• The Journal of Engineering Geology
• /
• v.8 no.2
• /
• pp.115-130
• /
• 1998

An analysis on landslide types and susceptibilities associated with geomorphic characteristics has been conducted with 916 landslide inventories in Yeonchon-Chulwon District, where two day's heavy rainfall was concentrated on July, 1996. The precipitation during the 2 days, which is equivalent to 0.372 of event cofficient, can cause large landslides based on Olivier's equation. Sliding materials are dominantly composed of debris mixed with rock fragments and soil derived from colluvium and residual soils. 66% of the landslides are belong to debris flow md 23% are due to sediments flow, in accordance with the classification of sliding materials. Most of landslides(> 90%) are small and shallow, less than l00m in length and about 1m in depth, and classified as transitional type. Granite is more susceptible as much as 4.7 times than metamorphic rocks and 2.7 times than volcanic rocks, probably due to higher weathering grade of granite. The highest landslide frequency is concentrated on the areas between 200 and 300m in height and on the slopes between $10-20^{\circ}$ in dgree. More than 50% of landslides occurred under these geomorphic conditions. Consequently, colluviums and residual soils distributed on the gentle slopes are most susceptible to the landslides of the area.