• Title/Summary/Keyword: 커널기법

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Performance Enhancement of Tree Kernel-based Protein-Protein Interaction Extraction by Parse Tree Pruning and Decay Factor Adjustment (구문 트리 가지치기 및 소멸 인자 조정을 통한 트리 커널 기반 단백질 간 상호작용 추출 성능 향상)

  • Choi, Sung-Pil;Choi, Yun-Soo;Jeong, Chang-Hoo;Myaeng, Sung-Hyon
    • Journal of KIISE:Software and Applications
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    • v.37 no.2
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    • pp.85-94
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    • 2010
  • This paper introduces a novel way to leverage convolution parse tree kernel to extract the interaction information between two proteins in a sentence without multiple features, clues and complicated kernels. Our approach needs only the parse tree alone of a candidate sentence including pairs of protein names which is potential to have interaction information. The main contribution of this paper is two folds. First, we show that for the PPI, it is imperative to execute parse tree pruning removing unnecessary context information in deciding whether the current sentence imposes interaction information between proteins by comparing with the latest existing approaches' performance. Secondly, this paper presents that tree kernel decay factor can play an pivotal role in improving the extraction performance with the identical learning conditions. Consequently, we could witness that it is not always the case that multiple kernels with multiple parsers perform better than each kernels alone for PPI extraction, which has been argued in the previous research by presenting our out-performed experimental results compared to the two existing methods by 19.8% and 14% respectively.

Prevention of Buffer Overflow Attack on Linux Kernel Level (리눅스 커널 수준에서의 버퍼오버플로우 공격 방지 기법)

  • 김홍철;송병욱;박인성;김상욱
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2001.11a
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    • pp.111-114
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    • 2001
  • 시스템 침입을 위해서 사용할 수 있는 공격 기법은 그 종류가 매우 다양하다. 그러나 최종적인 시스템 침입의 목표는 버퍼오버플로우 공격을 통한 관리자 권한의 획득이다. 버퍼오버플로우 현상은 메모리 공간의 경계 영역에 대한 프로그래밍 언어 수준의 검사 도구를 제공하지 않는 C/C++ 의 언어적 특성으로 인해 발생한다. 본 논문에서는 리눅스 커널 수준에서 시스템 보안을 위한 참조 모니터를 제안하고 이를 이용하여 버퍼오버플로우 공격에 대응할 수 있는 보안 기법을 제시한다.

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Ontology Alignment based on Parse Tree Kernel usig Structural and Semantic Information (구조 및 의미 정보를 활용한 파스 트리 커널 기반의 온톨로지 정렬 방법)

  • Son, Jeong-Woo;Park, Seong-Bae
    • Journal of KIISE:Software and Applications
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    • v.36 no.4
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    • pp.329-334
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    • 2009
  • The ontology alignment has two kinds of major problems. First, the features used for ontology alignment are usually defined by experts, but it is highly possible for some critical features to be excluded from the feature set. Second, the semantic and the structural similarities are usually computed independently, and then they are combined in an ad-hoc way where the weights are determined heuristically. This paper proposes the modified parse tree kernel (MPTK) for ontology alignment. In order to compute the similarity between entities in the ontologies, a tree is adopted as a representation of an ontology. After transforming an ontology into a set of trees, their similarity is computed using MPTK without explicit enumeration of features. In computing the similarity between trees, the approximate string matching is adopted to naturally reflect not only the structural information but also the semantic information. According to a series of experiments with a standard data set, the kernel method outperforms other structural similarities such as GMO. In addition, the proposed method shows the state-of-the-art performance in the ontology alignment.

Microkernel-based System Call Interposition Mechanism (마이크로커널 기반 시스템 콜 인터포지션 기법)

  • Kim, Young-Pil;Ko, Young-Woong;Hong, Chul-Ho;Kim, Jung-Nyu;Yoo, Hyuk
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2002.11a
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    • pp.183-186
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    • 2002
  • 시스템 콜 인터포지션 메커니즘은 침입 탐지 및 접근 제어와 같은 시스템 보안 기능을 강화하기 위해서 사용하는 방법이다. 현재까지 알려진 시스템 콜 인터포지션의 구현 방법은 크게 라이브러리 기반, 커널 기반 그리고 유저레벨 프로세스 기반의 접근방식이었다. 기존의 방식들은 대부분 범용적인 모노리틱커널에 적용되어 사용되고 있으며, 최근에 보안 운영체제로 개발되고 있는 마이크로커널 방식의 시스템에서는 적합하지 않다. 본 논문에서는 기존에 연구되었던 시스템 콜 인터포지션 방법들을 소개하고 마이크로커널 기반의 시스템 콜 인터포지션을 위한 메커니즘을 제안하고 있다. 제안된 메커니즘은 마이크로커널 위에 모니터 서버를 두고, IPC가 수행될 때 특정 시스템 콜을 비동기 IPC를 이용하여 감시하는 방식을 취하고 있다.

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A Study of USB Device Kernel Hardening Using DLM, in Linux Operating System (리눅스 운영체제에서 DLM을 이용한 USB 디바이스 커널 하드닝에 관한 연구)

  • Jang, Seung-Ju;Choi, Eun-Seok
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.693-698
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    • 2009
  • Computer system to operate normally without interruption, is one of the important issues. Likewise, a computer system to operate without interruption, failure to endure a variety of techniques, development and commercial use is arranged. Most guards will take a lot of technique failure endure. In this paper on the Linux operating system, dynamic module (DLM) to connect using the USB device to use USB devices can cause the symptoms to reduce the kernel PANIC hadeuning technique for studying the kernel.

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The Blocking of buffer overflow based attack for Linux kernel (리눅스 시스템의 버퍼 오버플로우 공격 대응 기법)

  • Kim, Jeong-Nyeo;Jeong, Gyo-Il;Lee, Cheol-Hun
    • The KIPS Transactions:PartA
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    • v.8A no.4
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    • pp.385-390
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    • 2001
  • In this paper, we describe a blocking method of buffer overflow attack for secure operating system. Our team developed secure operating system using MAC and ACL access control added on Linux kernel. We describe secure operating system (SecuROS) and standardized Secure utility and library. A working prototype able to detect and block buffer overflow attack is available.

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A Method of Embedded Linux Light-Weight for Efficient Application Execution (어플리케이션 처리속도 개선을 위한 임베디드 리눅스 경량화 기법)

  • Lee, Tae-Woo;Cho, Ji-Yong;Cho, Yong-Hwan
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.3
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    • pp.1-10
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    • 2013
  • In this paper, we propose a method of embedded linux light-weight to improve efficiency of application running on embedded systems. Three methods including fast booting scheme applying the Hibernation technique, JFFS2 file system optimization applying the Symbolic Link and virtual address mapping, kernel light-weight that guarantees the general purpose was applied. Since then check the system dependency and generate kernel image according to the target embedded kit. And embedded system performance of existing linux and linux which the method proposed in this paper was compared. In experimental result, the kernel size was 9.6% improved and the system booting time was 18% improved. And application processing speed on target embedded kit was improved 11% in the best case, 66% in the worst case. This result show that the light-weight method proposed in this paper is guarantee fast booting time and securing resources and it is good for the application processing speed improvement.

Quantile regression using asymmetric Laplace distribution (비대칭 라플라스 분포를 이용한 분위수 회귀)

  • Park, Hye-Jung
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.6
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    • pp.1093-1101
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    • 2009
  • Quantile regression has become a more widely used technique to describe the distribution of a response variable given a set of explanatory variables. This paper proposes a novel modelfor quantile regression using doubly penalized kernel machine with support vector machine iteratively reweighted least squares (SVM-IRWLS). To make inference about the shape of a population distribution, the widely popularregression, would be inadequate, if the distribution is not approximately Gaussian. We present a likelihood-based approach to the estimation of the regression quantiles that uses the asymmetric Laplace density.

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Audio Watermarking in Sub-band Signals Using Multiple Echo Kernel (다중 반향 커널을 이용한 부대역 신호 기반 오디오 워터마킹)

  • Oh In-Jung;Cho Jae-Won;Chung Hyun-Yeol;Jung Ho-Youl
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.355-358
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    • 2004
  • 최근 웨이블릿 변환을 이용하여 저주파수 부대역 신호를 반복적으로 분해하고 삽입된 워터마크 비트에 따라 특정 부대역 신호에 두개의 다른 반향 중 하나를 삽입하는 반향 삽입 기법을 제안하였다. 이 기법은 오디오 신호의 주파수 특성을 고려했기 때문에 시간 영역에서의 기존의 반향 삽입 기법에 비해 비가청성(inaudibility), 워터마크의 강인성(robustness) 및 용적성(capacity)을 모두 증가시킬 수 있다. 기존의 부대역 신호 기반 반향 삽입 기법이 단일 반향 커널만을 이용하였으나, 본 논문에서는 부대역 신호에 다중 반향 커널을 이용한 반향 삽입 기법을 제안한다. 이 기법은 주관적 왜곡(perceptibility)과 SNR(signal to Noise Ratio)과 같은 객관적인 왜곡 면에서, 원본 오디오 신호의 왜곡을 줄일 수 있다. 실험 결과를 통하여 기존의 방법에 비해 제안된 방법이 SNR과 DR(Detection Rate) 모두 좋은 성능을 보여 제안된 방법의 유효성을 입증하였다.

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A Virtualized Kernel for Effective Memory Test (효과적인 메모리 테스트를 위한 가상화 저널)

  • Park, Hee-Kwon;Youn, Dea-Seok;Choi, Jong-Moo
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.12
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    • pp.618-629
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    • 2007
  • In this paper, we propose an effective memory test environment, called a virtualized kernel, for 64bit multi-core computing environments. The term of effectiveness means that we can test all of the physical memory space, even the memory space occupied by the kernel itself, without rebooting. To obtain this capability, our virtualized kernel provides four mechanisms. The first is direct accessing to physical memory both in kernel and user mode, which allows applying various test patterns to any place of physical memory. The second is making kernel virtualized so that we can run two or more kernel image at the different location of physical memory. The third is isolating memory space used by different instances of virtualized kernel. The final is kernel hibernation, which enables the context switch between kernels. We have implemented the proposed virtualized kernel by modifying the latest Linux kernel 2.6.18 running on Intel Xeon system that has two 64bit dual-core CPUs with hyper-threading technology and 2GB main memory. Experimental results have shown that the two instances of virtualized kernel run at the different location of physical memory and the kernel hibernation works well as we have designed. As the results, the every place of physical memory can be tested without rebooting.