• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1185-1193
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• 2006

The next generation networked information system over unbounded internet is open to various network attacks and incidents, so many users suffer from damage and financial loss. In this paper we propose a survivability management model to evaluate the tradeoffs between the cost of defence mechanisms for information systems with weighted service and the resulting expected survivability after a network attack or occurrence of incidents. By varying the level of defence in the simulation, we examine how survivability changes according to the defense level. We derive a cost/survivability and weighted service/survivability curve that managers can use to decide on the appropriate level of defense for the network system of their organizations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2055-2062
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• 2013

Digital evidence which is the new form of evidence to crime makes little difference in value and function with existing evidences. As time goes on, digital evidence will be the important part of the collection and the admissibility of evidence. Usually a digital forensic investigator has to spend a lot of time in order to find clues related to the investigation among the huge amount of data extracted from one or more potential containers of evidence such as computer systems, storage media and devices. Therefore, these evidences need to be ranked and prioritized based on the importance of potential relevant evidence to decrease the investigate time. In this paper we propose a methodology which prioritizes order in which evidences are to be examined in order to help in selecting the right evidence for investigation. The proposed scheme is based on Fuzzy Multi-Criteria Decision Making, in which uncertain parameters such as evidence investigation duration, value of evidence and relation between evidence, and relation between the case and time are used in the decision process using the aggregation function in fuzzy set theory.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.214-222
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• 2018

Alane(aluminum trihydride, $AlH_3$) is a candidate material involving high energetic capacity for solid propellant or explosives. In this study aluminum trihydride-etherate ($AlH_3{\cdot}(C_2H_5)_2O$) was synthesized through a wet process, and solid alane was extracted by controlled crystallization. Alane crystals were grown during the crystallization step with phase conversion of aluminum trihydride-etherate to alane using an anti-solvent. Stable crystal forms were found by a 2 hour crystallization process at $85^{\circ}C$. Finally the extracted solid aluminium trihydride consisted mainly of ${\gamma}-type$ with $50-100{\mu}m$ in size.

• Journal of the Korean Chemical Society
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• v.50 no.6
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• pp.440-446
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• 2006

ZnO nanoparticles were prepared by laser ablation of the ZnO powder dispersed in deionized water and surfactant solutions, and characterized using UV-VIS absorption spectroscopy, X-ray diffractometer and Transmission electron microscopy(TEM). ZnO nanoparticles produced show the pure ZnO crystal state without mixed state with Zn(OH)2 or Zn, and have the band gap energy of 3.35 eV, which is comparable to that of bulk ZnO. While ZnO nanoparticles prepared in SDS solution have the average diameter of 28nm with near spherical shape, those prepared in CTAB solution have the average size of 40 nm with mainly rod-like shape. ZnO colloidal solution of CTAB is more stable than that of SDS. These difference according to surfactants can be explained by difference of electrostatic interaction between surface charge of ZnO and surfactant molecules and by solvation effect in solution.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.4
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• pp.259-269
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• 1999

Elastic wave velocity measurement technique such as impact-echo method and ultrasonic pulse velocity method has been successfully used to evaluate the moduli and strength of concrete. However, estimation results obtained by the NDT methods do not agree well with real things because longitudinal wave velocity is influenced by various factors. In this paper, among several factors influencing P-wave velocity, the influence of moisture content in concrete was investigated through the experiment. Test results show that longitudinal wave velocity is significantly affected by the moisture content of concrete, i.e., the lower moisture content. the lower velocity. Moisture content influences rod-wave velocity measured by impact-echo method stronger than ultrasonic pulse velocity measured by transmission method. During drying process with ages. the difference of increasing rate between longitudinal wave velocity and compressive strength of concrete is gradually increased. Therefore, to establish more accurate relationship between longitudinal wave velocity and strength, the difference of the increasing rate should be considered.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.211-217
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• 2010

It is important to measure the mechanical properties of nanostructures because they are required to determine the lifetime and reliability of nanodevices developed for various fields. In this study, tensile tests for a multi-walled carbon nanotube (MWCNT) and a ZnO nanorod were performed in a scanning electron microscope (SEM). The force sensor was a cantilever type and was mounted in front of a nanomanipulator placed in the chamber. The nanomanipulator was controlled using a joystick and personal computer. The nanostructures dispersed on the cut area of a transmission electron microscope (TEM) grid were gripped with the force sensor by exposing an electron beam in the SEM; the tensile tests were the performed. The in situ tensile loads of the nanostructure were obtained. After the tensile test, the cross-sectional areas of the nanostructures were observed by TEM and SEM. Based on the TEM and SEM results, the elastic modulus of the MWCNT and ZnO nanorod were calculated to be 0.98 TPa and 55.85 GPa, respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.33-39
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• 2008

Typhoon Lusa in 2002 and Typhoon Maemi in 2003 caused the worst damage of landslide and debris flow to Gangwon-do. This damage includes severe damage in riverside road. The damage register indicates that this damage is concentrated on mountain areas in Gangwon-do. In recent years, the studies on GIS application to predicting landslide and debris flow have been progressing actively. Landslide risk map managed by The Forest Service is the representative one. In this study, we generated landslide and debris flow hazard maps using statistical analysis and deterministic analysis in Gangnung area where Typhoons caused severe damage to riverside roads. We built damage point GIS DB from damage registers of National Road Maintenance Agency and field survey, and verified accuracy of landslide and debris flow hazard maps using GIS methods.

• 프린팅코리아
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• v.11 no.4
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• pp.86-104
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• 2012

4년마다 개최돼 인쇄 산업의 올림픽이라고 불리는 세계 최대 규모의 인쇄 기술 전시회인 드루파2012가 5월 3일부터 16일까지 독일 뒤셀도르프에서 개최된다. 전 세계 인쇄산업을 선도하는 전문 전시회인 드루파는 인쇄 산업과 기술을 비롯해 관련 산업 및 경제에 막대한 영향을 주는 전 세계 인쇄인들의 축제다. 전 세계 약 140개 국가에서 40만여 명이 드루파2012를 관람하기 위해 뒤셀도르프로 모여들 것으로 보인다. 방문객의 약 60%가 지난 드루파2008과 마찬가지로 독일 외 지역에서 오는 외국 방문객이다. 이는 드루파 전시회의 뛰어난 국제성을 증명하는 수치로 다른 어떤 전시회와도 비교할 수 없는 국제적 흡인력을 보여준다. 또한 40만 명의 방문객 중 약 78%가 각 기업 내 의사 결정권을 가진 주요 인사들이며 드루파 방문객의 98%는 재방문객이다. 이러한 결과는 드루파는 인쇄인들에게 필수 전시회라는 점을 보여준다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.75-77
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• 2013

엘리베이터 내에서는 흡연이 금지되어 있으며 엘리베이터 내에서 흡연을 하는 것은 매우 잘못된 일이다. 흡연은 우리 청소년과 여성들에게 매우 좋지 않다. 본 논문에서는 엘리베이터 내에서 흡연을 하는 사람을 추출하여 포렌식 증거 자료로 법원에 제출하기 위해서이다. 추출을 위하여 엘리베이터에 탄 사람의 얼굴 주위를 부분적으로 장면 전환 검출하여 추출한다. 얼굴 주변에 흰색 막대를 검출하는 방법으로 흡연 여부를 결정한다. 연기를 내뿜는 것에 관한 연구는 나중에 할 것이다. 장면 전환 검출은 컬러히스토그램으로 추출하도록 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.149.1-149.1
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• 2010

가스 하이드레이트는 작은 고체 부피 내에 막대한 양의 가스를 저장할 수 있다는 특징으로 인하여 최근 주목을 받고 있지만, 엔지니어링 분야에서는 천연가스 수송 파이프라인에 blockage problem을 일으키는 해로운 물질로 처음 관심을 받았다. 이러한 문제를 해결하기 위한 방법으로 초기에는 하이드레이트 형성영역을 벗어나도록 온도, 압력을 유지하기도 하였으나, 최근에는 다양한 형성 억제제가 사용되고 있다. 본 연구에서는 기존에 억제제로 알려져 있는 대표적인 알코올 화합물인 에탄올을 이용하여 고압의 메탄과 binary 하이드레이트의 형성 연구를 수행하였다. 다양한 농도의 에탄올을 이용하여 형성된 하이드레이트 샘플은 고체 NMR 분석을 통하여 분자 거동을 자세히 측정하였으며, 분말 XRD 분석을 통하여 헝성된 미세 결정 구조도 확인하였다. 본 연구에서 얻어진 결과는 에탄올 및 알코올 화합물의 가스 하이드레이트 형성 거동 및 binary guest 시스템에서의 tuning 효과에 대한 유용한 정보를 제시할 수 있을 것이라 판단된다.