• 한국통신학회논문지
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• 제38B권8호
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• pp.615-622
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• 2013

페이로드 시그니쳐 기반 분석 방법에서 정확한 시그니쳐는 분석 성능을 높이는데 있어 필수적이다. 하지만 정확한 시그니쳐를 생성하기 위한 수동생성 방법에는 한계가 있다. 따라서 이를 극복 하기 위해 페이로드 시그니쳐를 자동생성하기 위한 페이로드 시그니쳐 자동 생성 시스템을 제안한다. 또한 프로토콜 필터를 이용한 응용의 프로토콜 인식을 통해 시그니쳐 자동 생성의 효율성을 향상 시키고, 프로토콜 별 응용의 페이로드 시그니쳐를 자동 생성하여 세분화된 분석에 적용 할 수 있는 페이로드 시그니쳐 자동 생성 방법을 제안하였다. 본 논문에서 제안한 시스템의 타당성을 검증하기 위해 수동 생성 시그니쳐와 자동 생성 시그니쳐의 비교 및 프로토콜 별 자동 생성 시그니쳐를 통해 시스템의 타당성을 보였다.

• 인터넷정보학회논문지
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• 제12권6호
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• pp.19-33
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• 2011

효율적인 네트워크 관리를 위한 응용 트래픽 분석의 중요성이 강조되고 있다. 헤더 기반 분석 방법론은 기존 분석 방법론의 한계점들분석 오버헤드, 페이로드 암호화 등)을 극복하기 위해 응용 트래픽의 헤더 정보를 시그니쳐로 추출{IP address, port number, transport layer protocol TCP/UDP)}하여 트래픽을 분석한다. 헤더 기반 트래픽 분석 방법론은 헤더 정보를 사용하기 때문에 많은 양의 시그니쳐가 추출된다. 따라서 최적의 시그니쳐를 유지할 수 있는 관리 방법이 필요하다. 본 논문에서는 시그니쳐로 분석된 트래픽의 특성과 시그니쳐의 분석이력을 이용하여 최적의 시그니쳐를 관리하는 방법론을 제안한다. 또한, 실험과 검증을 통하여 헤더 시그니쳐 관리 방법의 타당성을 증명한다.

• 한국통신학회논문지
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• 제34권11B호
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• pp.1234-1244
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• 2009

오늘날의 네트워크에서는 다양한 응용의 등장으로 인해 트래픽이 복잡 다양해지고 있다. 이러한 상황 속에서 트래픽의 응용 별 분류에 대한 중요성은 날이 갈수록 증가하고 있다. 트래픽의 응용 별 분류에 대한 요구에 따라 기존에도 많은 연구가 이루어졌었다. 포트 기반의 분류, 페이로드 기반의 분류, 머신러닝 기반의 분류 방법들이 제안되었는데 아직 트래픽을 완벽하게 분류해내는 방법론은 개발되지 않은 실정이다. 최근 연구 중에는 플로우의 통계 정보를 이용한 방법론이 많이 연구되고 있다. 본 논문에서는 통계 시그니쳐를 통한 응용 트래픽 분류 방법론을 제안하고자 한다. 플로우 중 첫 N개의 패킷의 페이로드 크기와 방향을 이용하여 통계 시그니쳐를 생성하고, 이를 이용하여 응용 트래픽을 분류한다. 그리고 검증 시스템을 통해 본 분류 방법론이 높은 정확도의 분류 방법론이라는 것을 보인다.

• 무역상무연구
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• 제16권
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• pp.331-359
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• 2001

Uniform Electronic Transactions Act (1999) Drafted by the National Conference of Commissioners on Uniform State Laws. The Act allows the use of electronic records and electronic signatures in any transaction, except transactions subject to the Uniform Commercial Code. The fundamental purpose of this act is to remove perceived barriers to electronic commerce. The Act's a procedural statute. It does not mandate either electronic signatures or records, but provides a means to effectuate transactions when they are used. The primary objective is to establish the legal equivalence of electronic records and signatures with paper writings and manually-signed signatures. With regard to the general scope of the Act, the Act's coverage is inherently limited by the definition of "transaction." The Act does not apply to all writings and signatures, but only to electronic records and signatures relating to a transaction, defined as those interactions between people relating to business, commercial and governmental affairs. The exclusion of specific Articles of the Uniform Commercial Code reflects the recognition that, particularly in the case of Articles 5, 8 and revised Article 9, electronic transactions were addressed in the specific contexts of those revision processes. In the context of Articles 2 and 2A the UETA provides the vehicle for assuring that such transactions may be accomplished and effected via an electronic medium. At such time as Articles 2 and 2A are revised the extent of coverage in those Articles(Acts) may make application of this Act as a gap-filling law desirable. Similar considerations apply to the recently promulgated Uniform Computer Information Transactions Act (UCITA). Another fundamental premise of the Act is that it be minimalist and procedural. The general efficacy of existing law, in an electronic context, so long as biases and barriers to the medium are removed, confirms this approach. The Act defers to existing substantive law. Specific areas of deference to other law in this Act include: i) the meaning and effect of "sign" under existing law, ii) the method and manner of displaying, transmitting and formatting information in section 8, iii) rules of attribution in section 9, and iv) the law of mistake in section 10.

• Molecules and Cells
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• 제42권3호
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• pp.237-244
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• 2019

Understanding the mechanisms of cancer drug resistance is a critical challenge in cancer therapy. For many cancer drugs, various resistance mechanisms have been identified such as target alteration, alternative signaling pathways, epithelial-mesenchymal transition, and epigenetic modulation. Resistance may arise via multiple mechanisms even for a single drug, making it necessary to investigate multiple independent models for comprehensive understanding and therapeutic application. In particular, we hypothesize that different resistance processes result in distinct gene expression changes. Here, we present a web-based database, CDRgator (Cancer Drug Resistance navigator) for comparative analysis of gene expression signatures of cancer drug resistance. Resistance signatures were extracted from two different types of datasets. First, resistance signatures were extracted from transcriptomic profiles of cancer cells or patient samples and their resistance-induced counterparts for >30 cancer drugs. Second, drug resistance group signatures were also extracted from two large-scale drug sensitivity datasets representing ~1,000 cancer cell lines. All the datasets are available for download, and are conveniently accessible based on drug class and cancer type, along with analytic features such as clustering analysis, multidimensional scaling, and pathway analysis. CDRgator allows meta-analysis of independent resistance models for more comprehensive understanding of drug-resistance mechanisms that is difficult to accomplish with individual datasets alone (database URL: http://cdrgator.ewha.ac.kr).

• 센서학회지
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• 제31권5호
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• pp.330-336
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• 2022

This paper proposes a method to calibrate the electrode misplacement in underwater electric field sensor arrays (EFSAs) for accurate measurements of underwater electric field signatures. The electrode misplacement of an EFSA was estimated by measuring the electric field signatures generated by a known electric source and by comparing the measurements with the theoretical calculations under similar measurement conditions. When the EFSA measured the electric field signatures induced by an unknown electric source, the electric properties of the unknown electric source were approximated by considering the optimized estimation of the electrode misplacement of the EFSA. Finally, the measured electric field signatures were calibrated by calculating the theoretical electric field signatures to be measured with an ideally installed EFSA without electrode misplacement; the approximated electric properties of the unknown electric source were also taken into account. Simulations were conducted to test the proposed calibration method. The results showed that the electrode misplacement could be estimated. Further, the electric field measurements and the electric field-based localization of underwater vessels became more accurate after the application of the proposed calibration method. The proposed method will contribute to applications such as the detection and localization of underwater electric sources, which require accurate measurements of underwater electric field signatures.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.674-679
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• 1994

Acoustic signal such as speech and scattered sound, are generally a nonstationary process whose frequency contents vary at any instant of time. For time-varying signal, whether a nonstationary or a deterministic transient signal, a traditional frequency domain representation does not reveal the contents of signal characteristics and may lead to erroneous results such as the loss of desired characteristics features or the mis-interpretation for a wrong conclusion. A time-frequency domain representation is needed to characterize such signatures. Pseudo Wigner-Ville distribution (PWVD) is ideally suited for portraying nonstationary signal time-frequency domain and carried out by adapting the fast Fourier transform algorithm. In this paper, the important properties of PWVD were investigated using both stationary and nonstationry signatures by numerical examples PWVD was applied to acoustic sigtnatures to demonstrate its application for time-ferquency domain analysis.

• 대한원격탐사학회지
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• 제37권4호
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• pp.719-731
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• 2021

This study proposes a two-stage hybrid classification model for crop classification using multi-temporal remote sensing images; the model combines feature embedding by using an autoencoder (AE) with a convolutional neural network (CNN) classifier to fully utilize features including informative temporal and spatial signatures. Long short-term memory (LSTM)-based AE (LAE) is fine-tuned using class label information to extract latent features that contain less noise and useful temporal signatures. The CNN classifier is then applied to effectively account for the spatial characteristics of the extracted latent features. A crop classification experiment with multi-temporal unmanned aerial vehicle images is conducted to illustrate the potential application of the proposed hybrid model. The classification performance of the proposed model is compared with various combinations of conventional deep learning models (CNN, LSTM, and convolutional LSTM) and different inputs (original multi-temporal images and features from stacked AE). From the crop classification experiment, the best classification accuracy was achieved by the proposed model that utilized the latent features by fine-tuned LAE as input for the CNN classifier. The latent features that contain useful temporal signatures and are less noisy could increase the class separability between crops with similar spectral signatures, thereby leading to superior classification accuracy. The experimental results demonstrate the importance of effective feature extraction and the potential of the proposed classification model for crop classification using multi-temporal remote sensing images.

• 정보처리학회논문지C
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• 제17C권1호
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• pp.99-108
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• 2010

네트워크 트래픽 모니터링과 분석은 엔터프라이즈 네트워크의 효율적인 운영과 안정적 서비스를 제공하기 위한 필수적인 요소이다. 응용 레벨 트래픽의 분석을 위한 다양한 방법이 존재하지만 분류의 정확성, 분석률, 실용성을 고려했을 때 페이로드 시그니쳐 기반의 분석 방법은 가장 높은 성능을 보인다. 하지만 페이로드 시그니쳐를 수작업으로 추출하는 과정은 응용프로그램 및 응용 프로토콜에 대한 선행적인 분석이 필요하기 때문에 많은 시간과 인력이 요구된다. 또한 응용프로그램의 통합, 변경, 출현은 시그니쳐의 유지 및 관리에 대한 복잡성을 증대시킨다. 따라서 본 논문에서는 응용프로그램의 페이로드 시그니쳐 생성 과정의 단점을 보완할 수 있는 시그니쳐 자동 생성 시스템을 제안하여 시그니쳐 생성 효율을 향상시키며, 응용프로그램의 변화, 출현에 유연하게 대처할 수 있는 페이로드 시그니쳐 갱신 시스템을 구축하여 지속적으로 시그니쳐 유지, 관리가 가능하도록 하였다. 또한 학내망에 적용하여 제안한 시스템의 실용성을 증명하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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• pp.1572-1593
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• 2018

The diversity and fast growth of Internet traffic volume are highly influenced by mobile and computer applications being developed. Moreover, the developed applications are too dynamic to be identified and monitored by network administrators. Several approaches have been proposed to identify network applications, however, are still not robust enough to identify modern applications. This paper proposes both, TSA (Traffic collection, Signature generation and Applications identification) system and a derived algorithm so called CSP (Contiguous Sequential Patterns) to identify applications for management and security in IP networks. The major focus of this paper is the CSP algorithm which is automated in two modules (Signature generation and Applications identification) of the proposed system. The proposed CSP algorithm generates DNA-like unique signatures capable of identifying applications and their individual services. In this paper, we show that the algorithm is suitable for generating efficient signatures to identify applications and application services in high accuracy.