• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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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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• v.42 no.4
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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.

• Journal of the Korean Society of Safety
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• v.38 no.2
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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.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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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.

• Convergence Security Journal
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• v.14 no.5
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• pp.31-36
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• 2014

As security management center of financial area, financial ISAC monitors financial corporations and provides security services. Financial ISAC minimizes damage by responding quickly to external attack such as hacking, virus but it is poor at handling internal attack. For the efficient management and stable operation of information source, also to respond jointly to online hacking, the necessity of information sharing system increases day by day in and outside country. This paper proposes financial ISAC that can prevent a secondary damage of leakage information as well as providing security services. The proposed financial ISAC provides new password to financial corporation in which the same ID and password as leakage information are used and in case of financial information leakage it warns customers against phishing etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.12-14
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• 2018

Many posters and advertisements for fire prevention have long been known to warn of the danger of fire. The reason for this warning is that the damage of the fire is large. In addition, if the second damage occurs, the damage will be larger. In this study, we will design an automatic power circuit breaker that automatically cuts off the power if the temperature sensor is set to a certain temperature value and then goes up above that value. This study will minimize the secondary damage of fire.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.273-276
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• 2014

In 2014, the leakage of personal information from 3 credit card companies resulted in divulging approximately 10,000 customers' personal information. Although the credit card companies concluded that there was no secondary loss due to the leakage of personal information, secondary financial losses resulting from the leakage of personal information currently occur. In particular, hackers who employ smishing masquerade acquaintances by using the divulged personal information to ask payment for Ms. Kim's Sochi Olympics legal processing or exposed traffic violations. The hackers cause secondary financial losses through smartphones. This study aims to conduct a forensic analysis of smishing incidents in smartphones through the leakage of personal information, and to make a forensic analysis of financial losses due to the smishing incidents.

• Corrosion Science and Technology
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• v.14 no.6
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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.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.7
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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.