• Title/Summary/Keyword: SMPC

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Flexural analysis of thermally actuated fiber reinforced shape memory polymer composite

  • Tiwari, Nilesh;Shaikh, A.A.
    • Advances in materials Research
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    • v.8 no.4
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    • pp.337-359
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    • 2019
  • Shape Memory Polymer Composites (SMPC) have gained popularity over the last few decades due to its flexible shape memory behaviour over wide range of strains and temperatures. In this paper, non-linear bending analysis has been carried out for SMPC beam under the application of uniformly distributed transverse load (UDL). Simplified C0 continuity Finite Element Method (FEM) based on Higher Order Shear Deformation Theory (HSDT) has been adopted for flexural analysis of SMPC. The numerical solutions are obtained by iterative Newton Raphson method. Material properties of SMPC with Shape Memory Polymer (SMP) as matrix and carbon fibre as reinforcements, have been calculated by theory of volume averaging. Effect of temperature on SMPC has been evaluated for numerous parameters for instance number of layers, aspect ratio, boundary conditions, volume fraction of carbon fiber and laminate stacking orientation. Moreover, deflection profile over unit length and behavior of stresses across thickness are also presented to elaborate the effect of glass transition temperature (Tg). Present study provides detailed explanation on effect of different parameters on the bending of SMPC beam for large strain over a broad span of temperature from 273-373K, which encompasses glass transition region of SMPC.

Stochastic Model Predictive Control for Stop Maneuver of Autonomous Vehicles under Perception Uncertainty (자율주행 자동차 정지 거동에서의 인지 불확실성을 고려한 확률적 모델 예측 제어)

  • Sangyoon, Kim;Ara, Jo;Kyongsu, Yi
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.4
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    • pp.35-42
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    • 2022
  • This paper presents a stochastic model predictive control (SMPC) for stop maneuver of autonomous vehicles considering perception uncertainty of stopped vehicle. The vehicle longitudinal motion should achieve both driving comfortability and safety. The comfortable stop maneuver can be performed by mimicking acceleration profile of human driving pattern. In order to implement human-like stop motion, we propose a reference safe inter-distance and velocity model for the longitudinal control system. The SMPC is used to track the reference model which contains the position uncertainty of preceding vehicle as a chance constraint. We conduct simulation studies of deceleration scenarios against stopped vehicle in urban environment. The test results show that proposed SMPC can execute comfortable stop maneuver and guarantee safety simultaneously.

Proposal of SMPC Biometric Authentication System Based on Public Blockchain (퍼블릭 블록체인 기반 SMPC 생체인증 시스템 제안)

  • Ji-Su Doo;Hyeok Kang;Keun-Ho Lee
    • Journal of Internet of Things and Convergence
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    • v.9 no.2
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    • pp.77-82
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    • 2023
  • As the method of collecting and utilizing structured and unstructured data develops due to the influence of the Fourth Industrial Revolution, unwanted personal information data is also being collected and utilized, and hackers are attempting various attacks to steal information. As a result, the importance of information protection has increased, and various protection techniques have emerged, among which many studies have been conducted using decentralized techniques of blockchain and various algorithms to strengthen the security of biometric authentication techniques. This paper proposed a public blockchain biometric authentication system that allows users to protect their data in a safer biometric authentication method in the public blockchain and use it in the blockchain through signature with authenticated information.

Secure Multi-Party Computation Based on Homomorphic Encryption for Privacy Preserving in IoT Networks (IoT 네트워크에서 프라이버시 보호를 위한 동형암호화에 기반의 안전한 다자간 계산)

  • CHEN, Hao-Tian;Kim, Tae Woo;Park, Ji Su;Park, Jong Hyuk
    • Proceedings of the Korea Information Processing Society Conference
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    • 2021.11a
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    • pp.189-192
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    • 2021
  • 5G와 사물인터넷(IoT) 시대에 데이터의 크로스컴퓨팅은 연구, 의료, 금융, 민생 분야 등에 더 많은 지원을 할 수 있고 프라이버시 안전성이 중요해지고 있다. SMPC (Secure Multi-party Computation)은 서로 믿지 않는 참여자 간의 프라이버시 보호 시너지 컴퓨팅 문제를 해결하고, 데이터 수요자에게 원본 데이터를 누설하지 않는 범위 하에서의 다자간 컴퓨팅 능력을 제공한다. IoT 장치는 전력 소모와 지연에 제한을 받기 때문에 대부분의 장치가 여전히 경량화 보안 메커니즘에 속하고 IoT에서 트래픽의 데이터 통합관리가 어렵기 때문에 통신 중 신원인식과 데이터를 주고받는 단계에서 프라이버시 유출의 문제가 발생할 수 있고 심지어 DDOS공격, RelayAttack공격 등 사이버의 목적이 될 수도 있다. 본 논문에서 IoT 네트워크 데이터 통신 특징을 분석하고 동형 암호에 기반의 SMPC 연산 아키텍처를 제안한다. 제안하는 이키텍처에서 동형 암호를 사용함으로써 장치 데이터의 안전을 보장하는 동시에 전체 네트워크 안전성도 확보한다. SMPC 및 동형암호 기술의 지속적 발전에 따라 제안하는 아키텍처가 계속 개선할 잠재력이 있다.

An On-chip Multiprocessor Miroprocessor with Shared MMU and Cache

  • Lee, Yong-Hwan;Jeong, Woo-Kyeong;An, Sang-Jun;Lee, Yong-Surk
    • Journal of Electrical Engineering and information Science
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    • v.2 no.4
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    • pp.1-7
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    • 1997
  • A multiprocessor microprocessor named SMPC(scaleable multiprocessor chip) that contains tow IU (integer unit) is presented in this paper. It can execute multiple instructions from several tasks exploiting task-level parallelism that is free from instruction dependencies, and provide high performance and throughput on both single program and multiprogramming environments. the IU is a 32-bit scalar processor expecially designed to boost up the performance of string manipulations which are frequently used in RDBMS(relational data base management system) applications. A memory management unit and a data cache shared by two IUs improve the performance and reduce the chip area required. ETH SMPC is implemented in VLSI circuit by custom design and automated design tools.

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Preparation and Analysis of the Deployment Behavior of Shape Memory Polymer Composite Antennas (형상기억고분자 복합재료 안테나의 제조 및 전개 거동 분석)

  • An, Yongsan;Kim, Jinsu;Goo, Nam Seo;Park, Miseon;Kim, Yeontae;Park, Jong Kyoo;Yu, Woong-Ryeol
    • Composites Research
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    • v.31 no.6
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    • pp.347-354
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    • 2018
  • Shape memory polymer composites have been studied for deployable antennas in space because they have advantages of lightweight, large deformability, good processability, and low cost. In this research, shape memory polymer composites (SMPCs) were manufactured using carbon nanotubes (CNTs) as reinforcements and were used to fabricate SMPC antenna. The SMPCs were prepared by dispersing CNTs in the polymer matrix. Various dispersion methods were investigated to determine the most suitable one, focusing on the mechanical properties of SMPCs including their fracture behavior. The shape memory properties of SMPCs were measured and finally, the deployment behavior of the SMPC antenna was analyzed.

Cloud Computing and Secure Multi-Party Computation (클라우드 컴퓨팅과 안전성을 가진 다자간 연산)

  • Eun, Hasoo;Lee, Hoonjung;Son, Junggab;Oh, Heekuck;Kim, Sangjin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2011.11a
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    • pp.945-947
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    • 2011
  • 클라우드 컴퓨팅 인프라를 사용할 때 사용자의 민감한 정보가 포함된 데이터를 사용하게 될 수 있다. 데이터를 아웃소싱하여 처리하는 경우 클라우드 제공자가 데이터 처리자로서 사용자의 데이터에 접근해야 한다. 사용자는 데이터를 처리하는 과정에서 행하는 클라우드 제공자의 동작을 알 수 없으므로 클라우드 컴퓨팅을 사용하는 것을 불안해하게 되고 공개를 해도 되는 일부의 데이터만을 사용하게 된다. 본 연구에서는 클라우드 컴퓨팅을 통해 연산을 수행하는 환경에서 사용자의 데이터를 보호하기 위한 연구의 일환으로써, 시스템 및 환경을 정의하고 주로 발생할 수 있는 정보보호 위협을 정리하였다. 또한 현재 연구가 진행되고 있는 SMPC(Secure Multi-Party Computation)을 소개하고 이를 클라우드 컴퓨팅을 통해 연산을 수행하는 환경에 적용하기 위해 고려해야 할 사항들을 제시하며, 향후 연구 방향을 모색한다.