• Title/Summary/Keyword: Mitigation techniques

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A Study on the Frequency Sharing between HEO FSS System and GSO FSS Network in the 12GHz Band (12GHz 대역에서 HEO 위성시스템과 GSO 위성망간의 주파수 공유 방법 연구)

  • Lim, Sang-Hee;Seong, Hyang-Suk
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.567-571
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    • 2003
  • Owing to the insufficient satellite resources such as frequency and orbit, the interest in the sharing of these resources has been increasing. ITU-R has been studying on the power limitation, the interference mitigation techniques etc. in order to facilitate the frequency sharing between different systems. Therefore, we studied on the interference mitigation techniques between HEO FSS system and GSO FSS network. We performed the simulation using four mitigation techniques and, based on the results of simulation, evaluated these techniques.

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Experimental and Numerical Study on the Mitigation of High Explosive Blast using Shear Thickening based Shock-Absorbing Materials (전단농화유체기반의 충격완화물질을 이용한 고폭속 폭약의 폭발파 저감에 관한 실험 및 수치해석적 연구)

  • Younghun Ko
    • Explosives and Blasting
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    • v.41 no.3
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    • pp.1-12
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    • 2023
  • A basic assessment of techniques to mitigate the risk of blast shock waves from proximity explosions was conducted. Common existing techniques include using mitigant materials to form barriers around the explosive or in the direction of propagation of the shock wave. Various explosive energy dissipation mechanisms have been proposed, and research on blast shock wave mitigation utilizing impedance differences has drawn considerable interest. In this study, shear thickening fluid (STF) was applied as a blast mitigation material to evaluate the effectiveness of STF mitigation material on explosion shock wave mitigation through explosion experiments and numerical analysis. As a result, the effectiveness of the STF mitigant material in reducing the explosion shock pressure was verified.

Classification and Comparison of EMI Mitigation Techniques in Switching Power Converters - A Review

  • Yazdani, Mohammad Rouhollah;Farzanehfard, Hosein;Faiz, Jawad
    • Journal of Power Electronics
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    • v.11 no.5
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    • pp.767-777
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    • 2011
  • Power electronic systems such as switching power supplies are accounted as noise sources for other sensitive circuits. EMI caused by power converters can disturb the normal operation of the converter and other adjacent systems. Major research is concentrated on EMI mitigation for power converters in which the main concern is compliance with EMC standards to ensure proper operation of converters and nearby systems. This paper reviews EMI reduction techniques related to switching power converters with emphasis on the conducted EMI. A comprehensive review of significant research works is performed and various methods are thoroughly discussed and compared. Also, a classification of methods is presented. Moreover, converter prototypes are realized which contain several EMI mitigation techniques and their effects are presented via experimental results.

Water Environment and Mitigation Technique of Coastal Zone (연안역의 환경과 미티게이션 기술)

  • 최영박
    • Journal of the Korean Professional Engineers Association
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    • v.33 no.1
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    • pp.51-60
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    • 2000
  • The mitigation technique is to minimize influences to the environments, and it is one of the environmental management(or administration) to techniques. Its objective is to create sustainable environment by keeping human assistance to the environment as minimal as possible. It restores, creates, enhances, and most importantly preserves the environment by avoiding, minizing, rectifying, eliminating, and compensating the natural circumstances The evaluation of adverse effects to the environment and their reduction is as follow: HEP(Habitat Evaluation Procedure) WET(Wet land evaluation technique) HGM(Hydro Geomorphic Assessment) BEST(Biological Evaluation Standardized Technique) Since there are both pro and cons in the American and Japanese mitigation methods, it is hard to choose which one is better.

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Adaptive Mitigation of Narrowband Interference in Impulse Radio UWB Systems Using Time-Hopping Sequence Design

  • Khedr, Mohamed E.;El-Helw, Amr;Afifi, Mohamed Hossam
    • Journal of Communications and Networks
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    • v.17 no.6
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    • pp.622-633
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    • 2015
  • The coexistence among different systems is a major problem in communications. Mutual interference between different systems should be analyzed and mitigated before their deployment. The paper focuses on two aspects that have an impact on the system performance. First, the coexistence analysis, i.e. evaluating the mutual interference. Second aspect is the coexistence techniques, i.e. appropriate system modifications that guarantee the simultaneous use of the spectrum by different technologies. In particular, the coexistence problem is analyzed between ultra-wide bandwidth (UWB) and narrow bandwidth (NB) systems emphasizing the role of spectrum sensing to identify and classify the NB interferers that mostly affect the performance of UWB system. A direct sequence (DS)-time hopping (TH) code design technique is used to mitigate the identified NB interference. Due to the severe effect of Narrowband Interference on UWB communications, we propose an UWB transceiver that utilizes spectrum-sensing techniques together with mitigation techniques. The proposed transceiver improves both the UWB and NB systems performance by adaptively reducing the mutual interference. Detection and avoidance method is used where spectrum is sensed every time duration to detect the NB interferer's frequency location and power avoiding it's effect by using the appropriate mitigation technique. Two scenarios are presented to identify, classify, and mitigate NB interferers.

A Study on Injection Attacks and Defenses on Microsoft Windows (MS Windows에서 인젝션 공격 및 방어 기법 연구)

  • Seong, HoJun;Cho, ChangYeon;Lee, HoWoong;Cho, Seong-Je
    • Journal of Software Assessment and Valuation
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    • v.16 no.2
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    • pp.9-23
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    • 2020
  • Microsoft's Windows system is widely used as an operating system for the desktops and enterprise servers of companies or organizations, and is a major target of cyber attacks. Microsoft provides various protection technologies and strives for defending the attacks through periodic security patches, however the threats such as DLL injection and process injection still exist. In this paper, we analyze 12 types of injection techniques in Microsoft Windows, and perform injection attack experiments on four application programs. Through the results of the experiments, we identify the risk of injection techniques, and verify the effectiveness of the mitigation technology for defending injection attacks provided by Microsoft. As a result of the experiments, we have found that the current applications are vulnerable to several injection techniques. Finally, we have presented the mitigation techniques for these injection attacks and analyzed their effectiveness.

Managing the Vulnerability of Megacities in North America and Europe to Seismic Hazards

  • Waugh, William L.
    • Fire Science and Engineering
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    • v.15 no.2
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    • pp.20-30
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    • 2001
  • The science and technology of seismic hazard mitigation are increasingly being shared among scientists and policy makers around the world. Administrative expertise is also being shared. While there is still tremendous unevenness in technical and administrative capacities and resources, a global community of emergency managers is developing and there is a globalization of expertise. Hazards are better understood, tools for risk assessment are improving, techniques for hazard mitigation are being perfected, and communities and states are implementing more comprehensive disaster preparedness, response, and recovery programs. Priorities are also emerging and hazard mitigation has emerged as the priority of choice in North America and Europe. An increasingly important component of hazard mitigation is resilience, in terms of increased capacities for disaster mitigation and recovery at the community and even individual levels. Each year, more is known about the locations and natures of seismic hazards, although there are still unknown and poorly understood fault lines and limited understanding of related disasters such as tsunamis and landslides. More is known about the impact of earthquakes on the built environment, although nature still provides surprises to confound man's best extorts to reduce risk. More is known about human nature and how people respond to uncertain risk and when confronted by certain catastrophe. However, despite the increased understanding of seismic phenomena and how to protect people and property, there is much that needs to be done to reduce the risk, particularly in major metropolitan areas.

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ANALYSIS OF SPATIAL AND TEMPORAL ADAPTIVE PROCESSING FOR GNSS INTERFERENCE MITIGATION

  • Chang, Chung-Liang;Juang, Jyh-Ching
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.143-148
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    • 2006
  • The goal of this paper is to analyze, through simulations and experiments, GNSS interference mitigation performance under various types of antenna structures against wideband and narrowband interferences using spatial-temporal adaptive signal processing (STAP) techniques. The STAP approach, which combines spatial and temporal processing, is a viable means of GNSS array signal processing that enhancing the desired signal quality and providing protection against interference. In this paper, we consider four types of 3D antenna array structure - Uniform Linear Array (ULA), Uniform Rectangular Array (URA), Uniform Circular Array (UCA), and the Single-Ring Cylindrical Array (SRCA) under an interference environment. Analytical evaluation and simulations are performed to investigate the system performance. This is followed by simulation GPS orbits in interfered environment are used to evaluate the STAP performance. Furthermore, experiments using a 2x2 URA hardware simulator data show that with the removal of wideband and narrowband interference through the STAP techniques, the signal tracking performance can be enhanced.

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