• 한국농림기상학회지
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• 제7권4호
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• pp.258-264
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• 2005

The objectives of this study were to study 1) emergence of pine bark beetles, 2) larval density in residual timber on Idlest land by each felling season, and 3) the secondary damage rates in the tended forest. Pine forest land which had undergone tending had a higher secondary damage ratio $(59.6\%)$ by pine bark beetles than forest land that was not tended $(2.8\%)$. The number of escape holes averaged 11.3 0.31 per $250 cm^2$ on the bark of leaf trees in the tended forest. The number of escape holes was higher in the Jinju site than in the Hamyang site. The larval habitat density of pine bark beetles as compared with each felling period was higher after mid-October than in forests tended early in October. Thus, forests should be tended before early October in order to prevent secondary damage from pine bark beetles. Secondary damage in the tended forest was higher in the upper part $(75.5\%)$ of the tree crown than in the lower part $(49.2\%)$. The damage was higher in terminal shoots $(80\%)$ than in lateral shoots $(48\%)$. Therefore, secondary damage by pine bark beetles can cause deterioration of the elongation growth of the forest trees. In conclusion, if by-products of tended pine forest forests are neglected, they will be utilized as a propagation site for pine bark beetles (Blastophagus piniperda L). The propagated adults will damage the tender shoots of the leaf trees and thus seriously limittheir elongation.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.242-250
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• 2017

Purpose: This study was conducted to determine the appropriate operating conditions through a factorial experiment for the secondary separating part of the self-propelled pepper harvester. Methods: An experimental setup that simulates the secondary separating part of the self-propelled pepper harvester was organized. Test samples were classified into three types according to the number of peppers on a stem, and 12 sets were prepared for each type. Among the operating conditions of the secondary separating part, the rotational speed of drum B (four levels), radial clearance between drums and cylindrical teeth (three levels), and speed ratio between the three drums (two levels) were set as the test factors, and tests were repeated three times for different levels of each factor. The appropriate operating conditions were determined by analyzing the separation ratio and damage ratio of the peppers collected through the secondary separating part. Results: The test factors changed the overall separation ratio and overall damage ratio in similar trends. In other words, the conditions that caused high overall separation ratios also exhibited high overall damage ratios. Owing to the high overall damage ratio in the condition with the highest overall separation ratio, the operating conditions should be selected considering both ratios. Conclusions: When the condition with more than 60% of overall separation ratio and less than 15% of overall damage ratio was considered as the appropriate operating condition, 70 rpm of the rotational speed of drum B, 5 mm of the radial clearance between drums and cylindrical teeth, and 7:3:5 for the speed ratio of the three drums A, B, and C should be applied for the secondary separating part used in this study. Supplementary studies will be required in the future to find optimal operating conditions through the actual field test under further divided test factors.

• 한국안전학회지
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• 제38권2호
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• pp.36-43
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• 2023

In this study, a four-point bending test was conducted to assess and detect the damage to reinforced concrete structures using the acoustic emission (AE) technique. Based on the crack investigation results, flexural failure was classified into four stages and compared with the characteristic analysis results of AE parameters. The parametric characterization indicated that the activity of the primary AE signal was high in the early stage, and that of the second signal increased after the flexural cracks stabilized. Because the secondary AE signal included noise generated by friction, parameter-based analysis for damage assessment was performed using the primary signal; the secondary signal was used as complement. The activity analyses of the primary and secondary signals effectively classified crack propagation; however, determining the macrocracks and yielding of reinforcing bars had certain limitations. Nevertheless, applying the damage index with cumulative AE energy is a complementary technique for detecting and assessing structure damage that well detects the occurrence of macrocracks.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.244.2-244.2
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• 2013

Contact Pattern을 Plasma Etching을 통해 Pattering 공정을 진행함에 있어서 Plasma 내에 존재하는 High Energy Ion 들의 Bombardment 에 의해, Contact Bottom 의 Silicon Lattice Atom 들은 Physical 한 Damage를 받아 Electron 의 흐름을 방해하게 되어, Resistance를 증가시키게 된다. 또한 Etchant 로 사용되는 Fluorine 과 Chlorine Atom 들은, Contact Bottom 에 Contamination 으로 작용하게 되어, 후속 Contact 공정을 진행하면서 증착되는 Ti 나 Co Layer 와 Si 이 반응하는 것을 방해하여 Ohmic Contact을 형성하기 위한 Silicide Layer를 형성하지 못하도록 만든다. High Aspect Ratio Contact (HARC) Etching 을 진행하면서 Contact Profile을 Vertical 하게 형성하기 위하여 Bias Power를 증가하여 사용하게 되는데, 이로부터 Contact Bottom에서 발생하는 Etchant 로 인한 Damage 는 더욱 더 증가하게 된다. 이 Damage Layer를 추가적인 Secondary Damage 없이 제거하기 위하여 본 연구에서는 원자층 식각방법(Atomic Layer Etching Technique)을 사용하였다. 실험에 사용된 원자층 식각방법을 이용하여, Damage 가 발생한 Si Layer를 Secondary Damage 없이 효과적으로 Control 하여 제거할 수 있음을 확인하였으며, 30 nm Deep Contact Bottom 에서 Damage 가 제거될 수 있음을 확인하였다. XPS 와 Depth SIMS Data를 이용하여 상기 실험 결과를 확인하였으며, SEM Profile 분석을 통하여, Damage 제거 결과 및 Profile 변화 여부를 확인하였으며, 4 Point Prove 결과를 통하여 결과적으로 Resistance 가 개선되는 결과를 얻을 수 있었다.

• 융합보안논문지
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• 제14권5호
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• pp.31-36
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• 2014

금융ISAC은 금융분야의 보안관제센터로서 금융사를 모니터링하고 보안서비스를 제공한다. 금융ISAC은 해킹이나 바이러스 등 외부공격에 대해서는 신속한 대응을 통해서 피해를 최소화하지만 내부공격에는 대처하지 못하는 문제가 있다. 최근 정보자원의 효율적 관리와 안정적 운영을 위하여 그리고 온라인 해킹범죄에 공동으로 대응하기 위하여 정보공유시스템에 대한 필요성이 국내외를 막론하고 날로 증가하고 있다. 본 논문에서는 금융ISAC에 개인정보 공유분석 센터를 병행 설치하여 보안서비스 제공뿐만이 아니라 개인정보가 유출되었을 시 유출된 정보로 인한 2차 피해를 방지할 수 있는 개선된 금융ISAC을 제안한다. 제안된 금융ISAC은 금융사 정보유출시 유출정보와 같은 아이디와 비밀번호가 사용되는 다른 금융사에 새로운 비밀번호를 생성하여 제공하고 금융정보가 유출되었을 경우에는 피싱 등에 주의하라는 경고를 한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.12-14
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• 2018

오래전부터 화재 예방을 위한 여러 가지 포스터 및 광고 등으로 화재의 위험성을 지속적으로 알리고 있다. 이렇게 화재를 경고하는 이유는 화재의 피해가 크기 때문이다. 더불어 2차 피해가 발생한다면 피해 규모가 더욱 커질 것이다. 본 연구에서는 열 감지센서에 일정온도의 값을 설정하고 그 값 이상으로 올라간다면 자동으로 전력을 차단시키는 자동 전력차단기를 설계할 것이다. 본 연구를 통하여 화재 2차 피해를 최소화 시킬 수 있을 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.273-276
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• 2014

2014년 카드3사의 개인정보유출로 약 1건의 고객정보가 유출되었다. 카드사는 개인정보유출로 인한 2차 피해는 없다고 단정지었지만, 실제로 개인정보유출 2차 피해가 발생하고 있다. 특히 스마트폰에서 Smishing은 유출된 개인정보를 이용하여 지인을 가장한 송금과 소치올림픽 김모양 소송, 차량단속대상적발 등 개인정보 유출로 인한 2차피해가 스마트폰에서 Smishing사고가 발생하고 있다. 본 논문에서는 스마트폰 Smishing사고에 대한 개인정보유출에 대한 Forensic 하고 스미싱 사고로 인한 금융피해에 대한 Forensic을 분석 하고자 한다.

• Corrosion Science and Technology
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• 제14권6호
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• pp.325-330
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• 2015

Pipe wall-thinning by flow-accelerated corrosion (FAC) is a significant and costly damage of secondary system piping in nuclear power plants (NPPs). All NPPs have their management programs to ensure pipe integrity from wall-thinning. This study analyzed the pipe wall-thinning caused by changing the amine, which is used for adjusting the water chemistry in the secondary system of NPPs. The pH change was analyzed according to the addition of amine. Then, the wear rate calculated in two different amines was compared at the steam cycle in NPPs. As a result, increasing the pH at operating temperature (Hot pH) can reduce the rate of FAC damage significantly. Wall-thinning is affected by amine characteristics depending on temperature and quality of water.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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• pp.837-843
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• 1998

This paper presents the thermomechanical and fracture mechanics evaluation procedure of thermal striping damage on the secondary piping of LMFR using Green's function method and standard FEM. The thermohydraulic loading conditions used in the present analysis are simplified sinusoidal thermal loads and the random type data thermal load. The thermomechainical fatigue damage was evaluated according to ASME code subsectionNH. The analysis results of fatigue for the sinusoidal and random load cases show that fatigue failure would occur at a geometrically discontinuous location during 90,000 hours of operation The fracture mechanics analysis showed that the crack would be initiated at an early stage of the operation. The fatigue crack was evaluated to propagate up to 5 ㎜ along the thickness direction during the first 944 and 1083 hours of operation for the sinusoidal and the random loading cases, respectively.

• 전기학회논문지
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• 제61권7호
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• pp.937-943
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• 2012

Most of faults occurred in transmission lines are single-phase to ground faults and transient faults. Single-phase auto reclosing is an appropriate scheme to maintain the system stability and restore the system effectively when those faults are occurred. In single-phase auto reclosing scheme, the secondary arc is generated after faulted phase is tripped to eliminate the fault and it is sustained by the capacitive and inductive coupling to the healthy phases. It is important to reclose the faulted phase after fully extinction of secondary arc because of the damage applied to system. Therefore, it is necessary to research on the detection of secondary arc extinction to ensure high success rate of reclosing. In this step, firstly, the accurate modelling of secondary arc should be performed. In this paper, the modelling of secondary arc is performed by using EMTP-RV and the simulation results show that the implemented model is correct and effective.