• Title/Summary/Keyword: Fault Injection Analysis

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A Key Recovery Attack on HMAC using Fault Injection Attack (오류 주입 공격을 이용한 HMAC에 대한 키 복구 공격)

  • Jeong, Ki-Tae;Lee, Yu-Seop;Sung, Jae-Chul;Hong, Seok-Hie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.21 no.5
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    • pp.27-33
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    • 2011
  • At FDTC'05 and CISC-W'10, the authors showed that if they decrease the number of rounds of AES and Triple-DES by using the fault injections, it is possible to recover the secret key of the target algorithms, respectively. In this paper, we propose a key recovery attack on HMAC by using the main idea of these attacks. This attack is applicable to HMAC based on MD-family hash functions and can recover the secret key with the negligible computational complexity. Particularly, the attack result on HMAC-SHA-2 is the first known key recovery attack result on this algorithm.

Fault reactivation potential during $CO_2$ injection in the Gippsland Basin, Australia (호주 Gippsland Basin에서 $CO_2$ 주입 중 단층 재활성화의 가능성)

  • Ruth, Peter J. van;Nelson, Emma J.;Hillis, Richard R.
    • Geophysics and Geophysical Exploration
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    • v.9 no.1
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    • pp.50-59
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    • 2006
  • The risk of fault reactivation in the Gippsland Basin was calculated using the FAST (Fault Analysis Seal Technology) technique, which determines fault reactivation risk by estimating the increase in pore pressure required to cause reactivation within the present-day stress field. The stress regime in the Gippsland Basin is on the boundary between strike-slip and reverse faulting: maximum horizontal stress $({\sim}\;40.5\;Mpa/km)$ > vertical stress (21 Mpa/km) ${\sim}$ minimum horizontal stress (20 MPa/km). Pore pressure is hydrostatic above the Campanian Volcanics of the Golden Beach Subgroup. The NW-SE maximum horizontal stress orientation $(139^{\circ}N)$ determined herein is broadly consistent with previous estimates, and verifies a NW-SE maximum horizontal stress orientation in the Gippsland Basin. Fault reactivation risk in the Gippsland Basin was calculated using two fault strength scenarios; cohesionless faults $(C=0;{\mu}=0.65)$ and healed faults $(C=5.4;\;{\mu}=0.78)$. The orientations of faults with relatively high and relatively low reactivation potential are almost identical for healed and cohesionless fault strength scenarios. High-angle faults striking NE-SW are unlikely to reactivate in the current stress regime. High-angle faults oriented SSE-NNW and ENE-WSW have the highest fault reactivation risk. Additionally, low-angle faults (thrust faults) striking NE-SW have a relatively high risk of reactivation. The highest reactivation risk for optimally oriented faults corresponds to an estimated pore pressure increase (Delta-P) of 3.8 MPa $({\sim}548\;psi)$ for cohesionless faults and 15.6 MPa $({\sim}2262\;psi)$ for healed faults. The absolute values of pore pressure increase obtained from fault reactivation analysis presented in this paper are subject to large errors because of uncertainties in the geomechanical model (in situ stress and rock strength data). In particular, the maximum horizontal stress magnitude and fault strength data are poorly constrained. Therefore, fault reactivation analysis cannot be used to directly measure the maximum allowable pore pressure increase within a reservoir. We argue that fault reactivation analysis of this type can only be used for assessing the relative risk of fault reactivation and not to determine the maximum allowable pore pressure increase a fault can withstand prior to reactivation.

A Study on Failure Diagnosis System for a Hydraulic Pump in Injection Molding Machinery Using Vibration Analysis (진동 분석을 이용한 사출성형기 유압펌프 결함 진단 시스템에 관한 연구)

  • Kim, Taehyun;Jeon, Yongho;Lee, Moon Gu
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.3
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    • pp.343-348
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    • 2013
  • In line with the advances in factory automation, various pieces of equipment are now operated in batch processes controlled by computers. However, many kinds of faults can occur in complicated and large systems, which can result in low productivity and economic loss. The reliability and safety of systems have been studied because of the difficulty of determining the severity and location of faults. Therefore, it is necessary to detect and diagnose such faults in order to guarantee the reliability and safety of the equipment. In this paper, a diagnosis method for the ball bearings of a hydraulic pump is applied using a vibration signal for the maintenance of injection molding equipment. The bearings' defects are selected as a main failure mode through a failure mode and effect analysis (FMEA). Usually, there are nonlinear and impulse components of vibration in a ball bearing with faults. For the effective fault diagnosis of a ball bearing, nonlinear diagnostic methods and time-frequency analysis are applied, in addition to the methods currently used, such as power spectrum, time series analysis, and statistical methods. As a result of this study, a failure diagnosis system is provided that is useful even for non-experts. This is a condition-based method that makes it possible to resolve problems in a timely and economical way, in contrast to the prior method, which required regular but wasteful maintenance based on the experience of expensive external experts.

A Study on the Fail Safety of Electronics Power Steering Using Sensor Fusion (Sensor Fusion을 이용한 전자식 조향장치의 Fail Safety 연구)

  • Kim, Byeong-Woo;Her, Jin;Cho, Hyun-Duck;Lee, Young-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.8
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    • pp.1371-1376
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    • 2008
  • A Steer-by-Wire system has so many advantages comparing with conventional mechanical steering system that it is expected to take key role in future environment friendly vehicle and intelligent transportation system. The mechanical connection between the hand wheel and the front axle will become obsolete. SBW system provides many benefits in terms of functionality, and at the same time present significant challenges - fault tolerant, fail safety - too. In this paper, failure analysis of SBW system will be performed and than sensor fusion technique will be proposed for fail safety of SBW system. A sensor fusion logic of steering angle sensor by using steering angle sensor, torque sensor and rack position sensor will be developed and simulated by fault injection simulation.

Numerical Formulation of Thermo-Hydro-Mechanical Interface Element (열-수리-역학 거동 해석을 위한 경계면 요소의 수식화)

  • Shin, Hosung;Yoon, Seok
    • Journal of the Korean Geotechnical Society
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    • v.38 no.9
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    • pp.45-52
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    • 2022
  • Because discontinuity in the rock mass and contact of soil-structure interaction exhibits coupled thermal-hydromechanical (THM) behavior, it is necessary to develop an interface element based on the full governing equations. In this study, we derive force equilibrium, fluid continuity, and energy equilibrium equations for the interface element. Additionally, we present a stiffness matrix of the elastoplastic mechanical model for the interface element. The developed interface element uses six nodes for displacement and four nodes for water pressure and temperature in a two-dimensional analysis. The fully coupled THM analysis for fluid injection into a fault can model the complicated evolution of injection pressure due to decreasing effective stress in the fault and thermal contraction of the surrounding rock mass. However, the result of hydromechanical analysis ignoring thermal phenomena overestimates hydromechanical variables.

Quasi-Steady-State Analysis on the Effect of the STATCOM on FRT Performance of Fixed Speed Wind Turbines (준정상상태 해석을 통한 고정속 풍력 발전기의 FRT에 대한 STATCOM의 효과 분석)

  • Ahn, Seon-Ju;Hwang, Pyeong-Ik;Nam, Soon-Ryul;Kang, Sang-Hee;Moon, Seung-Il
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.4
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    • pp.686-692
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    • 2010
  • This paper analyzes the effect of the STATCOM on the improvement of the Fault Ride Through (FRT) capability of the fixed speed wind turbines(FSWTs). The steady-state models of the wind farm components, such as induction generator, capacitor bank, and the STATCOM, are developed based on the simplified equivalent circuit. Especially, the STATCOM is modeled as a controllable current source and a method that analytically determines the magnitude of the injection current is developed. For the quasi-steady-state(QSS) analysis, the steady-state model of the generator and STATCOM are merged with the dynamic model of drive train. The QSS simulation with the STATCOM shows that the STATCOM can enhance the FRT performance by improving the $W_r-T_e$ characteristics of the FSWTs.

A Hydro-Mechanical Basic Study on the Effect of Shut-in on Injection-Induced Seismic Magnitude (유체 주입 중단이 유발 지진 규모에 미치는 영향에 대한 수리역학적 기초 연구)

  • Yim, Juhyi;Min, Ki-Bok
    • Tunnel and Underground Space
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    • v.32 no.3
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    • pp.203-218
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    • 2022
  • A hydro-mechanical study was performed to analyze the relationship between the magnitude of injection-induced seismicity and shut-in. In hydraulic analysis, the suspension of fluid injection makes the pore pressure gradient smaller while the pore pressure at the pressure front can reach the critical value for several hours after shut-in, which leads to the additional slip with wider area than during injection. The hydro-mechanical numerical analysis was performed to model the simplified fault system, and simulated the largest magnitude earthquake during shut-in stage. The effect of the abrupt suspension of fluid injection on the large magnitude earthquake was investigated in comparison with the continuous injection. In addition to the pore pressure distribution, it was found that the geometry of multiple faults and the stress redistribution are also important in evaluating the magnitude of the induced seismicity.

A Study on Emulsified Fuel Conditions and the Behavior of Diesel Engine Injection System based on Data Analysis (데이터 분석 기반 유화연료 조건과 디젤엔진 분사시스템 거동에 관한 연구)

  • Kim, Min-Seop;Ejike, Akpudo Ugochukwu;Hur, Jang-Wook
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.7
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    • pp.80-88
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    • 2021
  • The behavior of the injection system was determined through FFT and PSD analysis of the pressure data of the common rail, and when the diesel fuel is mixed with water, the pressure data of the common rail, depending on the water content and engine rotation speed, represent a different frequency component distribution. Recently, a theory has been suggested that mixing diesel fuel with water controls engine overheating, fuel efficiency, NOx, CO, etc., but if water content exceeds 10%, it can have a fatal adverse effect on the engine's injection system. In the future, it is necessary to promote fault diagnosis and prediction studies of diesel engines using FFT and PSD results from common rail pressure data.

A Study on the Fail Safety Logic of Smart Air Conditioner using Model based Design (모델 기반 설계 기법을 이용한 지능형 공조 장치의 이중 안전성 로직 연구)

  • Kim, Ji-Ho;Kim, Byeong-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.12
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    • pp.1372-1378
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    • 2011
  • The smart air condition system is superior to conventional air condition system in the aspect of control accuracy, environmental preservation and it is foundation for intelligent vehicle such as electric vehicle, fuel cell vehicle. In this paper, failure analyses of smart air condition system will be performed and then sensor fusion technique will be proposed for fail safety of smart air condition system. A sensor fusion logic of air condition system by using CO sensor, $CO_2$ sensor and VOC, $NO_x$ sensor will be developed and simulated by fault injection simulation. The fusion technology of smart air condition system is generated in an experiment and a performance analysis is conducted with fusion algorithms. The proposed algorithm adds the error characteristic of each sensor as a conditional probability value, and ensures greater accuracy by performing the track fusion with the sensors with the most reliable performance.

Fault Reactivation Modeling Using Coupled TOUGH2 and FLAC3D Interface Model: DECOVALEX-2019 Task B (TOUGH2-FLAC3D Interface 모델을 통한 단층 재활성 모델링: DECOVALEX-2019 Task B)

  • Park, Jung-Wook;Park, Eui-Seob;Lee, Changsoo
    • Tunnel and Underground Space
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    • v.30 no.4
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    • pp.335-358
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    • 2020
  • We present a numerical model to simulate coupled hydro-mechanical behavior of fault using TOUGH-FLAC simulator. This study aims to develop a numerical method to estimate fluid injection-induced fault reactivation in low permeability rock and to access the relevant hydro-mechanical stability in rock as part of DECOVALEX-2019 Task B. A coupled fluid flow and mechanical interface model to explicitly represent a fault was suggested and validated from the applications to benchmark simulations and the field experiment at Mont Terri underground laboratory in Switzerland. The pressure build-up, hydraulic aperture evolution, displacement, and stress responses matched those obtained at the site, which indicates the capability of the model to appropriately capture the hydro-mechanical processes in rock fault.