• Title/Summary/Keyword: 오버 런

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A Method Verifying Execution Environment Integrity for Secure Execution of Packed Android Application (패킹된 안드로이드 어플리케이션의 안전한 실행을 위한 실행 환경 무결성 검증 기법)

  • Ha, Dongsoo;Oh, Heekuck
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.6
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    • pp.1553-1561
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    • 2018
  • The source code for Android is open and easy to modify depending on the purpose. Recently, this charateristic has been exploited to bypass the runtime protection technique and extract the original executable code. Unfortunately, Android devices are so fragmented that it is difficult to verify the integrity of the system. To solve this problem, this paper proposes a technique to verify the integrity of the execution environment indirectly using the features of the application permission. Before executing the original executable code, it loads and executes the dummy DEX file to monitor for abnormal events and determine whether the system is intact. The proposed technique shows a performance overhead of about 2 seconds and shows that it can detect the bypassing technique that is currently disclosed.

An Upshift Improvement in the Quality of Forklift's Automatic Transmission by Learning Control (학습제어를 이용한 지게차 자동변속기 상향 변속품질 개선)

  • Jung, Gyuhong
    • Journal of Drive and Control
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    • v.19 no.2
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    • pp.17-26
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    • 2022
  • Recently, automatic transmissions caused a good improvement in the shift quality of a forklift. An advanced shift control algorithm, which was based on TCU firmware, was applied with embedded control technology and microcontrollers. In the clutch-to-clutch shifting, one friction element is released and the other friction element is activated. During this process, if the release and application timings are not synchronized, an overrun or tie-up occurs and ultimately leads to a shift shock. The TCU, which measures only the speed of the forklift, inevitably applies the open-loop shift control. In this situation, the speed ratio does not change during the clutch fill. The torque phase occurs until the clutch is disengaged. In this study, an offline shift logic of the learning control was proposed. It induced a synchronous shift when the learning control progressed. During this process, the reference current trajectory of the release clutch was corrected and applied to the next upshift. We considered the results of the overrun/tie-up characteristics of the upshift performed immediately before. The vehicle test proved that the deviation in shift quality, which was caused by the difference in the mechanical characteristics of the clutch, could be improved by the learning control.

Design and Implementation of Static Program Analyzer Finding All Buffer Overrun Errors in C Programs (C 프로그램의 버퍼 오버런(buffer overrun) 오류를 찾아 주는 정적 분석기의 설계와 구현)

  • Yi Kwang-Keun;Kim Jae-Whang;Jung Yung-Bum
    • Journal of KIISE:Software and Applications
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    • v.33 no.5
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    • pp.508-524
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    • 2006
  • We present our experience of combining, in a realistic setting, a static analyzer with a statistical analysis. This combination is in order to reduce the inevitable false alarms from a domain-unaware static analyzer. Our analyzer named Airac(Array Index Range Analyzer for C) collects all the true buffer-overrun points in ANSI C programs. The soundness is maintained, and the analysis' cost-accuracy improvement is achieved by techniques that static analysis community has long accumulated. For still inevitable false alarms (e.g. Airac raised 970 buffer-overrun alarms in commercial C programs of 5.3 million lines and 737 among the 970 alarms were false), which are always apt for particular C programs, we use a statistical post analysis. The statistical analysis, given the analysis results (alarms), sifts out probable false alarms and prioritizes true alarms. It estimates the probability of each alarm being true. The probabilities are used in two ways: 1) only the alarms that have true-alarm probabilities higher than a threshold are reported to the user; 2) the alarms are sorted by the probability before reporting, so that the user can check highly probable errors first. In our experiments with Linux kernel sources, if we set the risk of missing true error is about 3 times greater than false alarming, 74.83% of false alarms could be filtered; only 15.17% of false alarms were mixed up until the user observes 50% of the true alarms.

Quality Characteristics of Ice Creams using Tarak (타락을 이용한 아이스크림류의 품질 특성)

  • Ko, Seong-Hee;Han, Young-Sook;Yoon, Hyun-Geun;Jang, Sung-Sik;Myoung, Kil-Sun;Kim, Soo-A;Shim, Jae-Hun;Park, Seon-Yeong;Lee, Hye-Jin;Lee, Kyung-Yeoun
    • Culinary science and hospitality research
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    • v.20 no.6
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    • pp.91-101
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    • 2014
  • This study examines ice cream products with higher preference as dessert food using Tarak which is Korean traditional fermented milk (sherbet 1 kind, ice milk 2 kinds(IM-2, IM-4), ice cream 1 kind (IC-6)), and investigates the quality characteristics of each Tarak ice cream. For viscosity of the mix for Tarak ice creams, sherbet showed the lowest, and IC-6 showed the highest, significantly. For overrun, at 10 minutes, IC-6 with high milk fat content showed a higher value, and at the final 30 minutes, there was no significant difference among all samples. For melting point, IC-6 showed the highest and sherbet showed the lowest. For number of lactic acid bacteria, sherbet showed 7.32 Log CFU/g and IM-2, IM-4 and IM-6 showed 8.35~8.49 Log CFU/g, not showing significant difference. For sensory test of Tarak ice creams, IC-6 showed milk flavor highest, 4.10, and for sourness, sherbet showed 4.20 and IM-2 showed 4.10. For sweet taste, IC-6 showed the highest 5.05, and for bitter, IC-6 showed the lowest, 1.65. For the degree of creaminess, IC-6 was assessed significantly higher as 4.60 and body sense was also assessed higher as 5.05. For acceptance of appearance, taste, flavor and texture, IC-6 was assessed significantly higher than the other samples and for overall acceptability, IC-6 was assessed the highest at 5.15, sherbet showed 3.75, IM-2 showed 3.05 and IM-4 showed 2.50. This suggests that for Tarak ice creams, sensory preference of ice creams with high milk fat content or sherbet with non milk fat content is high.