• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4588-4603
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• 2014

In this paper, we present a high-quality image authentication scheme based on absolute moment block truncation coding. In the proposed scheme, we use the parity of the bitmap (BM) to generate the authentication code for each compressed image block. Data hiding is used to authenticate whether the content has been altered or not. For image authentication, we embed the authentication code to quantization levels of each image block compressed by absolute moment block truncation coding (AMBTC) which will be altered when the host image is manipulated. The embedding position is generated by a pseudo-random number generator for security concerned. Besides, to improve the detection ability we use a hierarchical structure to ensure the accuracy of tamper localization. A watermarked image can be precisely inspected whether it has been tampered intentionally or incautiously by checking the extracted watermark. Experimental results demonstrated that the proposed scheme achieved high-quality embedded images and good detection accuracy, with stable performance and high expansibility. Performance comparisons with other block-based data hiding schemes are provided to demonstrate the superiority of the proposed scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.155-156
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• 2007

This paper presents the vision-based camber and optimal cutting line detection algorithm for hot-rolling process. It is important to measure the camber of head and tail part of strips because many problems are caused by the camber in the hot-rolling process. The hot-rolling process has time constraints. The camber detection algorithm of head and tail parts requires fast and less complex for satisfying time constraints. The proposed algorithm consists of two parts: measurement of the camber in the head and tail part of strips and decision part of the optimal cutting line of hot-rolled strip. First, we obtain the camber value of the strip from the difference between the real center line and the center line of head, tail part. Second, the head and tail part of strips isn't suitable for strips connections. Therefore, the cutting process is needed in the hot-rolling process. The optimal cutting line is determined by the head and tail images obtained from cameras. The algorithm is applied into the vision system with two area cameras, Matrox image processing board and host PC for verification.

• 한국정보전자통신기술학회논문지
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• 제10권1호
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• pp.38-45
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• 2017

정보 처리 기술의 컴퓨터 및 네트워크 의존도가 심화됨에 따라 컴퓨터 및 네트워크에 대한 침입 사례가 갈수록 증가하고 있다. 시스템 및 네트워크의 침입을 방지하기 위하여 호스트와 네트워크 기반 침입차단시스템(방화벽 등)이 개발되었지만 기존의 규칙 기반의 침입차단시스템만으로는 보안 관리에 많은 어려움이 있다. 이러한 이유로 인해 시스템 및 네트워크 자원에 대한 침입을 실시간으로 탐지하고 이에 대처하는 침입탐지시스템 개발에 대한 요구가 증가하고 있다. 본 논문에서는 비선형 자료에도 적용 가능하며 수렴성이 보장된 실시간 특징 추출 방법으로 APEX 알고리즘과 점증적 LS-SVM 분류기를 결합한 실시간 침입탐지 시스템을 개발하였다. 일반적으로 실시간 처리 방식은 메모리의 효율성이 좋고 학습 자료의 추가를 허용하는 장점이 있지만 일괄처리 방식에 비해 정확도가 떨어지는 단점이 있다. 따라서 제안한 시스템은 정확도 면에서도 일괄 처리 방식과 비슷한 성능을 나타내고 있어 상용화가 가능한 시스템이다.

• 한국수산과학회지
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• 제48권5호
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• pp.731-738
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• 2015

Nematode infection in the epithelial tissue of cultured rockfish Sebastes schlegeli was first reported in 2012. Since then, nematode infections have caused serious economic losses in rockfish aquaculture on the west coast of Korea. Taxonomic and life cycle information for this parasite are currently unknown. In this study, 18S rRNA and cytochrome c oxidase subunit I (COI) genes were used for molecular identification and polymerase chain reaction (PCR) to detect the invisible stages of this parasite. Nucleotide sequences of the 18S rRNA of the rockfish nematode showed 98% identity with that of Philometra morii. Therefore, this rockfish nematode was classified to the Philometridae family. However, we could not identify it to genus level using 18S rRNA. Its COI nucleotide sequences shared 85% and 82% identities with those of Bursaphelenchus sinensis and Philometra overstreeti, respectively. In addition, two gene-specific primer sets were designed based on the 18S rRNA gene to detect the intermediate host and nematode larvae. These primers were specific to this rockfish nematode without cross-reacting to other pathogens. The detection limit of the PCR assay using these primers was 1,000 copies of nematoda plasmid DNA. Therefore, the PCR assay described here is suitable for the detection of nematode DNA within rockfish. In addition, this PCR assay could be used to detect nematode larvae and the intermediate host.

• 한국구조물진단유지관리공학회 논문집
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• 제14권5호
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• pp.72-78
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• 2010

CFRP보강공법은 구조물에 내하력을 증가시키기 위해 사용되고 있으며 실제 교량에 적용빈도가 높고 연구 활용성에 대한 기대가 큰 공법이다. CFRP로 보강된 콘크리트 구조물은 외부에 에폭시 등으로 접착된 CFRP로 인하여 휨파괴 및 전단파괴 외에 부착파괴가 추가적으로 발생하게 되며 이러한 부착파괴가 전체거동을 지배하게 되는 경우가 대부분이며, 취성파괴를 유발하게 된다. 따라서 이러한 CFRP 부착파괴에 대한 모니터링은 매우 중요한 의미를 갖는다. 본 논문에서는 국부적인 손상 파악에 유리한 PZT센서를 이용한 임피던스 기반 손상검색 방법을 사용하여 콘크리트 균열과 CFRP 부착파괴 모니터링에 대한 적용가능성을 검증해 보았다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.549-555
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• 2003

The objective of かis study is to investigate the feasibility of piezoelectric transducers as a damage detection system for civil infrastructures. There have been considerable amount of efforts by the modal analysis community to localize damage and evaluate its severity without looking at a reliable way to excite the structure. The detection of damages by modal analysis and similar vibration techniques depends upon the knowledge and estimation of various modal parameters. In addition to the associated difficulties, such low-frequency dynamic response based techniques fail to detect incipient damages. Smart piezoelectric ceramic (PZT) transducers which act as both actuators and sensors in a self-analyzing manner are emerging to be effective in non-parametric health monitoring of structural systems. In this paper, we present the results of an experimental study for the detection of damages using smart PZT transducers on the steel plate. The method of extracting the impedance characteristics of the PZT transducer, which is electro-mechanically coupled to the host structure, is adopted for damage detection. Two damages are simulated and assessed by the bonded PZT transducers for characterization. The experimental results verified the efficacy of the proposed approach and provided a demonstration of good robustness at the realistic steel structures, emphasizing the great potential for developing an automated in situ structural health monitoring system for application to large civil infrastructures without the need to blow the modal parameters.

• 정보처리학회논문지C
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• 제12C권6호
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• pp.865-874
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• 2005

컴퓨터 시스템에 저장된 정보는 불법적인 접근, 악의적인 파괴 및 변경, 우연적인 불일치 등으로부터 보호되어야 한다. 본 논문에서는 이러한 공격을 탐지하고 방어할 수 있는 센서기반 침입탐지시스템을 제안한다. 제안된 시스템은 각 중요 디렉터리에 센서 파일을 각 중요 파일에 센서 데이터를 설치한다. 이들 센서 객체는 일종의 덫으로서, 센서 객체에 대한 접근은 침입이라고 간주된다. 이를 통해 불법적으로 정보를 복사하거나 빼내 가려는 가로채기 위협을 효과적으로 방어할 수 있다. 제안된 시스템은 리눅스 시스템 상에서 적재 가능한 커널 모듈(LKM: Loadable Kernel Module) 방식을 사용하여 구현되었다. 본 시스템은 폭 넓은 침입탐지를 위해 호스트 기반의 탐지 기법과 네트워크 기반의 탐지 기법을 서로 결합함으로써 잘 알려지지 않은 가로재기 공격도 탐지 가능하게 하였다.

• Parasites, Hosts and Diseases
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• 제44권2호
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• pp.101-116
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• 2006

Vaginal trichomoniasis, caused by Trichomonas vaginalis, is the most common sexually transmitted disease. More than 170 million people worldwide are annually infected by this protozoan. In the Republic of Korea, 10.4% of women complaining of vaginal symptoms and signs were found to be infected with T. vagina/is. However, despite its high prevalence, the pathogenesis of T. vaginalis infection has not been clearly characterized although neutrophil infiltration is considered to be primarily responsible for the cytologic changes associated with this infection. We hypothesized that trichomonads in the vagina sometime after an acute infection secrete proteins like excretory-secretory product that have a chemotactic effect on neutrophils, and that these neutrophils are further stimulated by T. vaginalis to produce chemokines like IL-8 and $GRO-\alpha$, which further promote neutrophil recruitment and chemotaxis. Thus, neutrophil accumulation is believed to maintain or aggravate inflammation. However, enhanced neutrophil apoptosis induced by live T. vaginalis could contribute to resolution of inflammation. Macrophages may constitute an important component of host defense against T. vaginalis infection. For example, mouse macrophages alone and those activated by lymphokines or nitric oxide are known to be involved in the extracellular killing of T. vaginalis. In the host, T. vaginalis uses a capping phenomenon to cleave host immunoglobulins with proteinases and thus escape from host immune responses. Recently, we developed a highly sensitive and specific diagnostic polymerase chain reaction (PCR) technique using primers based on a repetitive sequence cloned from T. vaginalis (TV-E650), and found that the method enables the detection of T. vaginalis at concentrations as low as 1 cell per PCR mixture.

• Journal of Information Processing Systems
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• 제13권5호
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• pp.1382-1396
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• 2017

In this paper, we analyze a recently proposed semi-fragile watermarking scheme based on local binary pattern (LBP) operators, and note that it has a fundamental flaw in the design. In this work, a binary watermark is embedded into image blocks by modifying the neighborhood pixels according to the LBP pattern. However, different image blocks might have the same LBP pattern, which can lead to false detection in watermark extraction process. In other words, one can modify the host image intentionally without affecting its watermark message. In addition, there is no encryption process before watermark embedding, which brings another potential security problem. To illustrate its weakness, two special copy-paste attacks are proposed in this paper, and several experiments are conducted to prove the effectiveness of these attacks. To solve these problems, an improved semi-fragile watermarking based on LBP operators is presented. In watermark embedding process, the central pixel value of each block is taken into account and Arnold transform is adopted to guarantee the security of watermark. Experimental results show that the improved watermarking scheme can overcome the above defects and locate the tampered region effectively.

• 한국정보통신학회논문지
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• 제13권11호
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• pp.2341-2348
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• 2009

호스트 기반 침입탐지 기법에는 시스템 호출 순서를 고려하는 방법과 시스템 호출 파라미터를 고려하는 방법이 있다. 이 두 방법은 프로세스의 시스템 호출이 일어나는 전 구간에서 시스템 호출 순서에 이상이 있거나 시스템 호출 파라미터의 순서 및 길이 등에 이상이 있는 경우에 적합하지만 긍정적 결함율과 부정적 결함율이 높은 단점이 있다. 이 논문에서는 시스템 호출을 이용한 방법에서 발생하는 긍정적 결함율과 부정적 결함율을 줄이기 위해서 단위 시간을 도입한 타임 윈도우 기반의 T-N2SCD 탐지 모델을 제안한다. 제안 모델의 실험에 사용된 데이터는 DARPA에서 제공된 데이터이며, 실험 결과 제안 모델은 다른 시간 간격 보다 1000ms 시간 간격으로 실험하였을 경우가 긍정적 결합률과 부정적 결합률이 가장 낮았다.