• 정보처리학회논문지A
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• 제13A권3호
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• pp.199-204
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• 2006

리눅스 운영체제에서 커널 개발자의 오류로 인하여 발생되는 시스템 정지 현상을 줄이기 위해서 커널 하드닝이 필요하다. 그러나 기존의 커널 하드닝 방식은 고장 감내 기능을 통하여 제공되고 있기 때문에 구현이 어려울 뿐만 아니라 많은 비용이 소요된다. 본 논문에서 제안하는 커널 하드닝 방식은 패닉이 발생한 커널 주소에 대한 커널 스택 내의 값들을 정상적인 값으로 복구하기 위해서 커널 내의 panic() 함수 등 커널의 일부분을 수정하므로, 적은 비용으로 시스템 가용성을 높일 수 있다. 제안한 방식의 실험을 위하여 네트워크 모듈에 강제적인 패닉 현상 유발시키고, 잘못된 스택 값을 정상적인 값으로 복구하는 동작을 확인하였다.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.57-62
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• 2022

The Sambodana project is a mobile communication security system development project using Hardening Android. The initial idea for this project is that information leakage occurs outside of a communications application with end-to-end cryptographic security. Android hardening prevents unwanted applications and bloatware from being installed, such as unavailable Google Play Store or install restrictions.

• 한국정보통신학회논문지
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• 제11권1호
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• pp.173-180
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• 2007

본 논문은 리눅스 커널 운영체제에서 커널 개발자의 실수나 의도하지 않은 오류 및 시스템 오류로 인하여 발생되는 시스템 정지 현상을 줄이기 위해서 커널 스택의 복구를 통한 커널 하드닝 기능을 구현한다. 본 논문에서 제안하는 커널 하드닝 기능은 panic이 발생한 커널 주소에 대해서 커널 스택 내의 값들을 정상적인 값으로 복구함으로써 정상적인 시스템 동작을 보장한다 본 논문에서 제안한 커널 하드닝 기능을 리눅스 커널 중에서 많이 사용하는 네트워크 모듈에 적용하였다. 커널 스택 복구를 통한 커널 하드닝 기능의 실험을 위하여 네트워크 모듈에 강제적인 panic 현상을 유발시키고, 잘못된 스택 값의 복구를 통해서 정상 동작을 실험하였다.

• 정보처리학회논문지A
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• 제11A권4호
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• pp.227-234
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• 2004

본 논문은 리눅스 커널 운영체제에서 커널 개발자의 실수나 의도하지 않은 오류 등으로 인하여 발생되는 시스템 정지 현상 또는 시스템 패닉 현상을 줄이기 위한 커널 하드닝 구현 내용을 제안한다. 본 논문에서 제안하는 커널 하드닝 기능은 문제가 발생한 리눅스 커널 부분을 수행중인 프로세스를 정지시킴으로써 안정적인 커널 수행을 보장한다. 그러나 커널 하드닝 기능을 구현할 경우에 문제가 있는 모든 프로세스를 무조건 복구하는 것이 아니라 복구 가능성을 판별하여, 복구 가능한 프로세스에 대해서만 동작이 되도록 한다. 오류가 발생한 커널 코드에 대해서 복구 가능한 경우에는 ASSERT( ) 함수에서 복구가 가능하도록 구현되었다.

• Earthquakes and Structures
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• 제14권5호
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• pp.459-465
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• 2018

Reducing response of buildings during earthquakes by mass dampers, has been examined in many articles and books. Nowadays, many researchers are trying to realistically examine this type of dampers by new methods of performance. In this paper, for the better study of tuned mass damper (TMD), two schematic models are presented for a passive TMD with softening stiffness (softening TMD) and a passive TMD with hardening stiffness (hardening TMD). Then by modeling and analysis of the damper on a single degree of freedom (SDOF) structure and an 11-story steel building, the dampers performance was evaluated. State space was used for damper and structure modeling and to solve nonlinear equations, the Newton-Raphson method was used. The results show that when the structure is subjected to the Chi-Chi earthquake, response of the sixth floor in the system without TMD reduces 54.0% in comparison to the structure with softening TMD. This percentage of reduction for hardening TMD is 55.0%. Also for the Tabas earthquake, reduction in the RMS acceleration of the sixth floor in the system with hardening TMD is 96.2% more than the structure without TMD. This percentage of reduction for hardening TMD is 96.3%.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.265-266
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• 2007

• 한국지진공학회논문집
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• 제20권5호
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• pp.319-329
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• 2016

The Eradi Quake System (EQS) is a seismic isolation bearing system designed to minimize forces and displacements experienced by structures subjected to ground motion. The EQS dissipates seismic energy through friction of Poly Tetra Fluoro Ethylene (PTFE) disk pad. In general, a force-displacement relationship of EQS has post yield stiffness hardening during large inelastic displacement. In this study, seismic responses of seismically isolated nuclear power plant (NPP) subjected to design basis earthquake (DBE) and beyond design basis earthquakes (150% DBE and 167% DBE) are compared considering the post yield stiffness hardening effect of EQS. From the results, it can be observed that if the post-yield stiffness hardening effect of EQS is increased, the displacement response of EQS is reduced, and the acceleration and shear responses of containment structures of NPP is increased.

• 한국압력기기공학회 논문집
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• 제13권2호
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• pp.67-74
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• 2017

Recently there have been many concerns on structural integrity of nuclear piping under seismic loadings. In terms of failure of nuclear piping due to seismic loadings, an important failure mechanism is low cycle fatigue with large cyclic displacements. To investigate the effects of seismic loading on low cycle fatigue behavior of nuclear piping, the cyclic behavior of materials and nuclear piping needs to be accurately estimated. In this paper, the non-linear finite element (FE) analyses have been carried out to evaluate the effects of three different cyclic hardening models on cyclic behavior of materials and nuclear piping, such as isotropic hardening, kinematic hardening and combined hardening.

• The Korean Journal of Ceramics
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• 제3권4호
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• pp.235-238
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• 1997

Basic properties of new cement pastes based on the system $CaO-Al_2O_3-P_O_5-H_2O$were studied Phosphoric acid solutions and calcium dialuminate clinkers synthesized by the hydration-burning method were used for liquid and powder components of the paste, respectively Variation in the compositions of the paste was achieved by changing the liquid/powder ratio and the concentration of phosphoric acid solution. The hardening rate of the paste was so largely affected by the amount of phosphoric acid that hardening was inhibited with the low-concentrated solution but was explosively accelerated with the high-concentrated solution. The phosphoric acid solutions of concentration of 45~50% and the liquid/powder ratio of 0.5~1.5 were favoured for the high early-strength cement paste with the reasonable hardening rate and high strength. The binding phase of hardened paste was the dense amorphous gel of the system $CaO-Al_2O_3-P_O_5-H_2O$. in which the unreacted calcium dialuminate grains were embeded.

• 펄프종이기술
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• 제46권4호
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• pp.85-92
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• 2014

The disposal of the paper mill sludge and the paper mill sludge ash become more important issue, because the environment regulation becomes more strict. In this study, the new mulching system was developed by using the paper sludge ash. The soil surface hardening mechanism for mulching with paper sludge ash, red clay and coal ash was evaluated. Since the CaO in the paper sludge ash provided the harden structure with water, the surface hardening mulching structure could cover the field surface and prevent the germination of weeds. More than 50 w.t.% of red clay and 10 w.t.% of paper sludge ash were required to create the solid soil surface structure for mulching. The field test with the new soil surface hardening mulching system for three months showed the generation of weeds could successfully be inhibited by the system.