• Title/Summary/Keyword: Update

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A New Penalty Parameter Update Rule in the Augmented Lagrange Multiplier Method for Dynamic Response Optimization

  • Kim, Min-Soo;Choi, Dong-Hoon
    • Journal of Mechanical Science and Technology
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    • v.14 no.10
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    • pp.1122-1130
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    • 2000
  • Based on the value of the Lagrange multiplier and the degree of constraint activeness, a new update rule is proposed for penalty parameters of the ALM method. The theoretical exposition of this suggested update rule is presented by using the algorithmic interpretation and the geometric interpretation of the augmented Lagrangian. This interpretation shows that the penalty parameters can effect the performance of the ALM method. Also, it offers a lower limit on the penalty parameters that makes the augmented Lagrangian to be bounded. This lower limit forms the backbone of the proposed update rule. To investigate the numerical performance of the update rule, it is embedded in our ALM based dynamic response optimizer, and the optimizer is applied to solve six typical dynamic response optimization problems. Our optimization results are compared with those obtained by employing three conventional update rules used in the literature, which shows that the suggested update rule is more efficient and more stable than the conventional ones.

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An Efficient Software Update Technique with Code-Banking & Delta-Image for Wireless Sensor Networks (무선 센서 네트워크상에서 코드뱅킹 및 델타이미지 기반의 효율적인 센서노드 소프트웨어 업데이트 기법)

  • Nam, Young-Jin;Nam, Min-Seok;Park, Young-Kyun;Kim, Chang-Hoon;Lee, Dong-Ha
    • IEMEK Journal of Embedded Systems and Applications
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    • v.4 no.3
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    • pp.103-111
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    • 2009
  • Software update has been regarded as one of fundamental functions in wireless sensor networks. It can disseminate a delta-image between a current software image operating on a sensor node and its new image in order to reduce an update image(transmission data) size, resultantly saving energy. In addition, code-banking capability of micro-controllers can decrease the update image size. In order to maximize the efficiency of the software update, the proposed scheme exploits both the delta-image and the code-banking at the same time. Besides, it additionally delivers a recovery delta-image to properly handle abnormal conditions, such as message corruptions and unexpected power-off during the update.

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Threats and response measures according to the type of software updates (소프트웨어 업데이트 유형별 위협요소 및 대응방안)

  • Lee, Daesung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.277-279
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    • 2014
  • In case of APT attacks, the update server is being used as a means of dissemination, the update program is running malicious code or data in applications such as anti-virus signature is vulnerable to manipulation, SW Update threat identification and prevention measures are urgently required. This paper presents a natiional and international SW update structure, update process exploits and response measures to examine, Through the extraction/analysis of a domestic famous SW update log, we are willing to select the necessary component of the normal program update to identify a white list.

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The Evaluation of the Various Update Conditions on the Performance of Gravity Gradient Referenced Navigation

  • Lee, Jisun;Kwon, Jay Hyoun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.6
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    • pp.569-577
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    • 2015
  • The navigation algorithm developed based on the extended Kalman filter (EKF) sometimes diverges when the linearity between the measurements and the states is not preserved. In this study, new update conditions together with two conditions from previous study for gravity gradient referenced navigation (GGRN) were deduced for the filter performance. Also, the effect of each update conditions was evaluated imposing the various magnitudes of the database (DB) and the sensor errors. In case the DB and the sensor errors were supposed to 0.1 Eo and 0.01 Eo, the navigation performance was improved in the eight trajectories by using part of gravity gradient components that independently estimate states located within trust boundary. When applying only the components showing larger variation, around 200% of improvement was found. Even the DB and sensor error were supposed to 3 Eo, six update conditions improved performance in at least seven trajectories. More than five trajectories generated better results with 5 Eo error of the DB and the sensor. Especially, two update conditions successfully control divergence, and bounded the navigation error to the 1/10 level. However, these update conditions could not be generalized for all trajectories so that it is recommended to apply update conditions at the stage of planning, or as an index of precision of GGRN when combine with various types of geophysical data and algorithm.

A Remote Firmware Update Mechanism for a TDMA-based Bidirectional Linear Wireless Sensor Network (양방향 통신을 지원하는 시분할 기반 선형 무선 센서 네트워크를 위한 원격 펌웨어 업데이트 방법)

  • Moon, Jung-Ho;Kim, Dae-Il;Park, Lae-Jeong;Lee, Hyung-Bong;Chung, Tae-Yoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.8
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    • pp.867-875
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    • 2009
  • A wireless sensor network inherently comprises a plurality of sensor nodes widely deployed for sensing environmental information. To add new functions or to correct some faulty functions of an existing wireless sensor network, the firmware for each sensor node needs to be updated. Firmware update would be quite troublesome if it requires the gathering, reprogramming, and redeploy of all of already deployed sensor nodes. Over-the-air programming (OTA) facilitates the firmware update process, thereby allowing convenient maintenance of an already-deployed sensor network. This paper proposes and implements a remote firmware update mechanism for a TDMA-based wireless sensor network, in which the firmware for sensor nodes constituting the TDMA-based sensor network can be easily updated and the update process can be conveniently monitored from a remote site. We verify the validity of the proposed firmware update method via experiments and introduce three wireless sensor networks installed in outdoor sites in which the proposed firmware update mechanism has been exploited.

Overlay Multicast Update Strategy Based on Perturbation Theory

  • Shen, Ye;Feng, Jing;Ma, Weijun;Jiang, Lei;Yin, Min
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.1
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    • pp.171-192
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    • 2017
  • The change of any element in the network is possible to cause performance degradation of the multicast network. So it is necessary to optimize the topology path through the multicast update strategy, which directly affects the performance and user experience of the overlay multicast. In view of the above, a new multicast tree update strategy based on perturbation theory Musp (Multicast Update Strategy based on Perturbation theory) is proposed, which reduces the data transmission interruption caused by the multicast tree update and improves user experiences. According to the multicast tree's elements performance and the topology structure, the Musp strategy defines the multicast metric matrix and based on the matrix perturbation theory it also defines the multicast fluctuation factor. Besides it also demonstrates the calculability of the multicast fluctuation factor presents the steps of the Musp algorithm and calculates the complexity. The experimental results show that compared with other update strategies, as for the sensitivity of the multicast fluctuation factor's energized multicast tree to the network disturbance, the maximum delay of the Musp update strategy is minimal in the case of the local degradation of network performance.

Threats according to the Type of Software Updates and White-List Construction Scheme for Advanced Security (소프트웨어 업데이트 유형별 위협요소와 안전성 강화를 위한 화이트리스트 구성 방안)

  • Lee, Daesung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1369-1374
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    • 2014
  • In case of APT attacks, the update server is being used as a means of dissemination, the update program is running malicious code or data in applications such as anti-virus signature is vulnerable to manipulation, SW Update threat identification and prevention measures are urgently required. This paper presents a natiional and international SW update structure, update process exploits and response measures to examine, Through the extraction/analysis of a domestic famous SW update log, we are willing to select the necessary component of the normal program update to identify a white list.

Bayesian model update for damage detection of a steel plate girder bridge

  • Xin Zhou;Feng-Liang Zhang;Yoshinao Goi;Chul-Woo Kim
    • Smart Structures and Systems
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    • v.31 no.1
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    • pp.29-43
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    • 2023
  • This study investigates the possibility of damage detection of a real bridge by means of a modal parameter-based finite element (FE) model update. Field moving vehicle experiments were conducted on an actual steel plate girder bridge. In the damage experiment, cracks were applied to the bridge to simulate damage states. A fast Bayesian FFT method was employed to identify and quantify uncertainties of the modal parameters then these modal parameters were used in the Bayesian model update. Material properties and boundary conditions are taken as uncertainties and updated in the model update process. Observations showed that although some differences existed in the results obtained from different model classes, the discrepancy between modal parameters of the FE model and those experimentally obtained was reduced after the model update process, and the updated parameters in the numerical model were indeed affected by the damage. The importance of boundary conditions in the model updating process is also observed. The capability of the MCMC model update method for application to the actual bridge structure is assessed, and the limitation of FE model update in damage detection of bridges using only modal parameters is observed.

Analysis of Design Error in Windows Update and Automatic Updates, and the Solutions (Windows Update 및 Automatic Updates의 설계 오류 분석 및 해결 방안)

  • Kim, Yun-Ju;Yun, Young-Tae;Kang, Sung-Moon
    • Convergence Security Journal
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    • v.6 no.3
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    • pp.107-115
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    • 2006
  • It discovered a design error from the module to search required installing security patch of Windows Update and Automatic Updates that Microsoft supports it to install security patch easily and quickly. It explains and tests security patch-disguise attack by this error. Security patch-disguise attack is to maintains a vulnerability and to be not searched the security patch simultaneously. Also it composes an attack scenario. Is like that, it proposes the method which solves an design error of the module to search required installing security patch.

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Performance Analysis of an Adaptive Link Status Update Scheme Based on Link-Usage Statistics for QoS Routing

  • Yang, Mi-Jeong;Kim, Tae-Il;Jung, Hae-Won;Jung, Myoung-Hee;Choi, Seung-Hyuk;Chung, Min-Young;Park, Jae-Hyung
    • ETRI Journal
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    • v.28 no.6
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    • pp.815-818
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    • 2006
  • In the global Internet, a constraint-based routing algorithm performs the function of selecting a routing path while satisfying some given constraints rather than selecting the shortest path based on physical topology. It is necessary for constraint-based routing to disseminate and update link state information. The triggering policy of link state updates significantly affects the volume of update traffic and the quality of services (QoS). In this letter, we propose an adaptive triggering policy based on link-usage statistics in order to reduce the volume of link state update traffic without deterioration of QoS. Also, we evaluate the performance of the proposed policy via simulations.

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