• Title/Summary/Keyword: TLS

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2D Image Reconstruction of Earth Model by Electrical Resistance Tomography (ERT를 이용한 2차원 대지모델 영상복원)

  • Boo, Chang-Jin;Kim, Ho-Chan;Kang, Min-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3460-3467
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    • 2013
  • The In this paper, we have made numerical experiments to compare 2D image reconstruction algorithm of earth model by electrical resistance tomograpy (ERT). Gauss-Newton, simultaneous iterative reconstruction technieque (SIRT) and truncated least squares (TLS) approaches for Wenner and Schlumberger electrode arrays are presented for the solution of the ERT image reconstruction. Computer simulations show that the Gauss-Newton and TLS approach in ERT are proper for 2D image reconstruction of an earth model.

Experimental Study of Waste Tire Powder-Added Lightweight Soil as Flowable Backfill (유동성 뒷채움재인 폐타이어 혼합경량토에 대한 실험적 연구)

  • Kim, Yun-Tae;Kang, Hyo-Sub
    • Journal of Ocean Engineering and Technology
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    • v.22 no.5
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    • pp.112-118
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    • 2008
  • The purpose of this study was to determine the engineering and environmental properties of the waste tire powder-added lightweight soil (TLS) used as flowable backfill. The TLS used in this experiment consisted of dredged soil, bottom ash, waste tire powder and cement. Test specimens were prepared with various contents of waste tire powder ranging from 0% to 100% at 25% intervals and water contents ranging from 140% to 200% by the weight of the dry dredged soil. Several series of unconfined compression tests, flow tests, and leaching tests were carried out. Experimental results for the TLS indicated that the unconfined compressive strength, secant modulus (), and unit weight of the TLS decreased with an increase in waste tire powder content. However, as the waste tire powder content increased, the stress-strain relationship of the TLS showed more ductile behavior rather than brittle behavior. The flow value increased with an increase in water content, but decreased with an increase in waste tire powder content. The result of the leaching test showed that the leaching amounts of heavy metals were lower than the permitted limits suggested by the Ministry of Environment.

A Performance Evaluation of EAP-TLS Authentication Model in the AAAv6 (AAAv6에서의 EAP-TLS 인증모델 성능평가)

  • Jeong, Yun-Su;Kim, Hyung-Do;Lee, Hae-Dong;Kim, Hyun-Gon;Lee, Sang-Ho
    • The KIPS Transactions:PartC
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    • v.11C no.3
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    • pp.309-318
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    • 2004
  • AAAv6-based Diameter method is using in the user authentication to satisfy the users' increasing user authentication demand and to supply a safe communication between mobile node and server in the Mobile IP. therefore, In this paper, We design a model of server capacity based on EAP-TLS that in one of AAAv6 models with mobility among domains to get the optimized capacity index of the server for user authentication accomplishment. We elicitat the authentication capacity index for each server of which is accomplishing in user authentication using DSA/RSA algorithm and purpose the optimized condition for the AAAv6 capacity by the index.

End-to-end MQTT security protocol using elliptic curve cryptography algorithm (타원곡선암호 알고리즘을 이용한 종단간 MQTT 보안 프로토콜)

  • Min, Jung-Hwan;Kim, Young-Gon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.5
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    • pp.1-8
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    • 2019
  • Internet of Things (IoT) is proliferating to provide more intelligent services by interconnecting various Internet devices, and TCP based MQTT is being used as a standard communication protocol of the IoT. Although it is recommended to use TLS/SSL security protocol for TCP with MQTT-based IoT devices, encryption and decryption performance degenerates when applied to low-specification / low-capacity IoT devices. In this paper, we propose an end-to-end message security protocol using elliptic curve cryptosystem, a lightweight encryption algorithm, which improves performance on both sides of the client and server, based on the simulation of TLS/SSL and the proposed protocol.

Error in Variable FIR Typed System Identification Using Combining Total Least Mean Squares Estimation with Least Mean Squares Estimation (입출력 변수에 부가 잡음이 있는 FIR형 시스템 인식을 위한 견실한 추정법에 관한 연구)

  • Lim, Jun-Seok
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.2
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    • pp.97-101
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    • 2010
  • FIR type system identification with noisy input and output data can be solved by a total least squares (TLS) estimation. However, the performance of the TLS estimation is very sensitive to the ratio between the variances of the input and output noises. In this paper, we propose an iterative convex combination algorithm between TLS and least squares (LS). This combined algorithm shows robustness against the noise variance ratio. Consequently, the practical workability of the TLS method with noisy data has been significantly broadened.

A Comparison Study on Total Least Squares and Least Squares (토털최소제곱법과 최소제곱법의 비교연구)

  • 이임평;최윤수;권재현
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.10a
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    • pp.15-19
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    • 2003
  • The Total Least Squares (TLS) method is introduced in comparison with the conventional Least Squares (LS) method. The principles and mathematical models for both methods are summarized and the comparison results from their applications to a simple geometric example, fitting a straight line to a set of 2D points are presented. As conceptually reasoned, the results clearly indicate that LS is more susceptible of producing wrong parameters with worse precision rather than TLS. For many applications in surveying, can adjustment computation and parameter estimation based on TLS provide better results.

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Image Reconstruction of Subspace Object Using Electrical Resistance Tomography

  • Boo, Chang-Jin;Kim, Ho-Chan;Lee, Yoon-Joon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2480-2484
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    • 2005
  • Electrical resistance tomograpy (ERT) maps resistivity values of the soil subsurface and characterizes buried objects. The characterization includes location, size, and resistivity of buried objects. In this paper, truncated least squares (TLS) is presented for the solution of the ERT image reconstruction. Results of numerical experiments in ERT solved by the TLS approach is presented and compared to that obtained by the Gauss-Newton method.

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A Gain-Phase Loop Shaping Method of QFT using TLS (TLS를 이용한 QFT의 이득-위상 루프형성법)

  • Kim, Ju-Sik;Jeong, Su-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.51 no.2
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    • pp.94-98
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    • 2002
  • QFT(Quantitative Feedback Theory) is a very practical design technique that emphasizes the use of feedback for achieving the desired system performance tolerances in despite of plant uncertainty and disturbance. The gain-phase loop shaping procedure of QFT is employed to design controller, until the bounds at desired frequencies are satisfied. This paper presents a transfer function synthesis using TLS(Total Least Squares) and offers a loop shaping method with the suggested technique. An example illustrates a feasibility of the presented algorithm.

Performance Improvement of SSL/TLS Handshake Protocol through extension of a Session Resume (Session Resume의 기한 연장을 이용한 SSL/TLS Handshake 프로토콜의 성능 개선)

  • 박지철;한명진;이경현
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.610-612
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    • 2002
  • 전송계층에서의 안전한 통신을 위한 Secure Sockets Layer(SSL)와 Transport Layer Security(TLS)의 Handshake 프로토콜에서 Session ID의 저장이 매우 짧은 시간 동안 저장됨으로 전체적인 Full Handshake의 횟수가 증가한다. 따라서, 안전한 Session resume 보장함으로 서버의 session cache 기한을 연장할 수 있으며 전체적인 Full Handshake 프로토콜의 횟수를 줄일 수 있다. 본 논문에서는 Handshake 프로토콜의 성능 개선을 위하여 S/key와 같은 해쉬의 일방향 성질을 이용하는 개선된 Session resume의 방안을 제안한다.

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Specialized intrusion detection system for TLS (TLS에 특화된 침입탐지시스템)

  • Park, KeunHo;Shon, TaeShik
    • Proceedings of the Korea Information Processing Society Conference
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    • 2015.10a
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    • pp.862-864
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    • 2015
  • 최근 몇 년 사이 FREAK, POODLE, HEARTBLEED, CRIME등등 TLS와 관련된 많은 취약점이 발생하였다. 이러한 취약점들은 해당 TLS버전을 사용하지 않거나 업데이트를 함으로서 예방할 수 있다. 하지만 오래된 서버를 사용하거나 낮은 버전의 TLS만을 지원하여 업데이트를 못하는 경우가 있고, 이러한 서버들은 취약점에 무방비상태로 노출되어있다. 그래서 이러한 서버들에게 TLS관련 취약점을 미리 알려주기 위해 Snort라는 툴을 사용하여 연구를 하였다.