• Title/Summary/Keyword: isolation system

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A Study on Actuator Fault Detection and Isolation in Airplanes using Fuzzy Logic (퍼지로직을 이용한 항공기 고장 검출 및 분리)

  • Lee Jang-Ho;Kim You-Dan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.3 s.18
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    • pp.140-148
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    • 2004
  • Fault detection and isolation(FDI) and reconfigurable flight control system provide better survivability even though actuator faults occur. In this study, a new fault detection and isolation algorithm is proposed using fuzzy logic. When the FDI system detects the actuator fault, the fuzzy logic investigates the state variables to find which actuator has fault. Proposed fuzzy detection algorithm detect not only a single fault but also multiple faults. After detecting the fault, the reconfigurable flight control system begins operating for compensating the effects of the fault. A numerical simulation using six degree-of-freedom nonlinear aircraft model is performed to verity the performance of the proposed fault detection and isolation scheme.

Implementation of Performance Isolation with Network Virtualization in SR-IOV (SR-IOV에서 네트워크 가상화를 통한 Performance Isolation의 구현)

  • Ahn, Sung-Won;Park, Dae-Young;Lee, Jong-Won;Yoo, Chuck
    • Proceedings of the Korean Information Science Society Conference
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    • 2011.06d
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    • pp.194-197
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    • 2011
  • 네트워크 가상화 기술은 하드웨어적인 제약사항을 완화시켜 다양한 서비스를 제공하는 네트워크 토폴로지를 구성할 수 있도록 하는 기술로써, 미래 인터넷 환경과 클라우드 컴퓨팅을 지원 할 수 있는 기술이다. 또한 가상화된 네트워크를 제공하기 위한 소프트웨어 기반의 라우터는 하드웨어의 라우터보다 상대적으로 비용이 저렴하고 높은 유연성과 유지 보수성을 갖는다. 소프트웨어 기반의 라우터를 통하여 물리적인 네트워크 위에서 각기 다른 서비스를 제공하는 다양한 가상 네트워크들을 공존하게 하고, 다양한 서비스를 효과적으로 제공하기 위해서는 각 네트워크의 독립성과 서비스의 품질 제어가 필요하다. 이 논문에서는 네트워크 가상화를 통하여 각 가상 네트워크들의 독립성을 보장하는 Network Isolation 기술과 QoS 보장을 위한 동적인 대역폭 조절을 제공하는 Performance Isolation 기술을 제안한다. 이를 통하여 기존 하드웨어 라우터에서는 제공되지 않은 높은 유연성 과 다양한 응용, 비용의 절감, 유지 보수의 용이성 등을 제공 할 수 있다.

A Study on the Intrusion Detection Method using Firewall Log (방화벽 로그를 이용한 침입탐지기법 연구)

  • Yoon, Sung-Jong;Kim, Jeong-Ho
    • Journal of Information Technology Applications and Management
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    • v.13 no.4
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    • pp.141-153
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    • 2006
  • According to supply of super high way internet service, importance of security becomes more emphasizing. Therefore, flawless security solution is needed for blocking information outflow when we send or receive data. large enterprise and public organizations can react to this problem, however, small organization with limited work force and capital can't. Therefore they need to elevate their level of information security by improving their information security system without additional money. No hackings can be done without passing invasion blocking system which installed at the very front of network. Therefore, if we manage.isolation log effective, we can recognize hacking trial at the step of pre-detection. In this paper, it supports information security manager to execute isolation log analysis very effectively. It also provides isolation log analysis module which notifies hacking attack by analyzing isolation log.

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Design of the Cradle for the Improvement of Efficiency of Vibration Isolation of a Precision Machinery (초정밀 가공장비의 진동절연용 크레들 설계)

  • Hong, Seok-In;Jang, Han-Kee;Kim, Ho-Sang;Lee, Dae-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.954-954
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    • 2005
  • In this study new vibration isolation system was designed so as to decouple translational motion and rotational motion of a workstation as well as to maximize an efficiency of vibration isolation. Whole motion of the workstation as well as the transmitted vibration from the floor were compared at the two conditions; with and without the cradle system. It was shown that the cradle system had a clear effect to suppress the roiling motion of the workstation.

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Time and frequency domain identification of seismically isolated structures: advantages and limitations

  • Kampas, G.;Makris, N.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.249-270
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    • 2012
  • This paper investigates the effectiveness of widely used identification methods to identify the response of seismically isolated structures supported on bearings with bilinear behavior. The paper shows that while both time domain and frequency domain methods predict with high accuracy the modal characteristics of structures isolated by linear isolation system, their performance degrades appreciably when the isolation system exhibits bilinear behavior even when its strength assumes moderate values (say 5% of the weight). The paper also shows that the natural period of isolated structure that results from bilinear isolation systems can be satisfactorily predicted with wavelet analysis.

Lightweight Capability-Based Access Control System on File Descriptor via ARM PA (ARM PA를 통한 경량화된 파일 디스크립터 권한 관리 시스템)

  • Kyuwon Cho;Hojoon Lee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.2
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    • pp.319-323
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    • 2023
  • In intra-process isolation, file descriptors work as another attack vector from the memory corruption attacks. The attacker can read or write by corrupting file descriptors so they can escape the isolation. In this paper, we propose new lightweight capability-based access control system on file descriptor using ARM's hardware extension, PA(Pointer Authentication). Our system was implemented on Linux kernel module, only shows 5% overhead to control the access on the file descriptor.

Effect of Rocking Behavior of Isolated Nuclear Structures and Sampling Technique for Isolation-System Properties on Clearance-to-stop (면진 원전구조물의 전도거동과 면진시스템 특성에 대한 샘플링 기법이 정지거리에 미치는 영향)

  • Han, Min Soo;Hong, Kee Jeung;Cho, Sung Gook
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.6
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    • pp.293-302
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    • 2015
  • ASCE 4 requires that a hard stop be built around the seismic isolation system in nuclear power plants. In order to maintain the function of the isolation system, this hard stop is required to have clearance-to-stop, which should be no less than the 90th-percentile displacements for 150% Design Basis Earthquake (DBE) shaking. Huang et al. calculated clearance-to-stop by using a Latin Hypercube Sampling technique, without considering the rocking behavior of the isolated structure. This paper investigates the effects on estimation of clearance-to-stop due to 1) rocking behavior of the isolated structure and 2) sampling technique for considering the uncertainties of isolation system. This paper explains the simplified analysis model to consider the rocking behavior of the isolated structure, and the input earthquakes recorded at Diablo Canyon in the western United States. In order to more accurately approximate the distribution tail of the horizontal displacement in the isolated structure, a modified Latin Hypercube Sampling technique is proposed, and then this technique was applied to consider the uncertainty of the isolation system. Through the use of this technique, it was found that rocking behavior has no significant effect on horizontal displacement (and thus clearance-to-stop) of the isolated structure, and the modified Latin Hypercube Sampling technique more accurately approximates the distribution tail of the horizontal displacement than the existing Latin Hypercube Sampling technique.

A Study on the Architectural Planning of Material Handling System for the Airborne Infection Isolation Hospitals (호흡기 감염 격리병원의 물류시스템 계획에 관한 연구)

  • Choi, Kwangseok;Kwon, Soon Jung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.2
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    • pp.63-72
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    • 2017
  • Purpose: The purpose of this study is to review the material handling system of the Airborne Infection Isolation Hospitals which is the one of the key elements of infection control and to improve the basic data for the planning and design of those facilities. Methods: Research was conducted by literature reviews and case studies for the material handling system of domestic and foreign Isolation hospitals. Results: The result of this study can be summarized into three points. First, a general isolation unit and a high level isolated unit need to be distinguished in terms of efficiency and safety. In particular, it is desirable that a high level isolated unit have to completely separate clean and soiled circulations, and soiled corridor should be installed by those means. By doing this, the medical staff can observe patient rooms and supply clean materials directly in the clean zone without wearing PPE, so that safety and work efficiency can be improved at the same time. Second, for the safe disposal of wastes, it is desirable to install a dedicated sterilizer per ward and sterilize it at least in the ward. In addition, It is desirable to install a central waste treatment room and a dedicated soiled corridor in consideration of the inadequate handling capacity and emergency situation. Third, the characteristics of material flow chart in the negative pressured isolation hospitals and the corresponding material handling system have been presented. Implications: Infection control is very important in safety, but it is necessary to respond to the symptoms of the patient.

Shaking Table Test of Isolated EDG Model (면진된 모형 비상디젤발전기의 지진응답 실험)

  • Kim, Min-Kyu;Choun, Young-Sun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.3 s.55
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    • pp.33-42
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    • 2007
  • In this study, for research on an improvement of the seismic safety of an EDG system, a small scale EDG system was manufactured. For the isolation system, the Coil Spring-Viscous Damper systems were selected. For the shaking table test, 3 kinds of seismic motions were selected which had different frequency contents. In this study, the isolation effects were different and they depended on the input seismic motion. In the case of an NRC earthquake which had low fiequency contents, the isolation effects of the horizontal direction were 20%. But for the seismic motions which had high fiequency contents, the isolation effects were $50{\sim}70%$. In the case of the vertical direction, poor isolation effects were observed. It was because the design properties and the real properties of the isolation system were a little different.

Seismic Response Analysis of Computer Floors Using Base Isolation System (면진장치를 적용한 컴퓨터실 바닥의 지진응답해석)

  • 이경진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.424-431
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    • 2000
  • After the Kobe earthquake(1995) in Japan, the Izmit earthquake(1997) in Turkey and the Chi-chi earthquake(1999) in Taiwan, the small-to-medium-sized earthquakes occurred in the Koreans peninsula and this shows the fact that Korea is not located in the safety zone of earthquake. The main concept of base isolation system is to reduce the member forces by decreasing the earthquake forces transmitted to superstructure instead of the conventional techniques of strengthening the structural members. This study investigates the effect of seismic response attenuation of computer floors using base isolation systems

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