• Title/Summary/Keyword: Defense method

Search Result 2,436, Processing Time 0.037 seconds

A Study on the Effective Preprocessing Methods for Accelerating Point Cloud Registration

  • Chungsu, Jang;Yongmin, Kim;Taehyun, Kim;Sunyong, Choi;Jinwoo, Koh;Seungkeun, Lee
    • Korean Journal of Remote Sensing
    • /
    • v.39 no.1
    • /
    • pp.111-127
    • /
    • 2023
  • In visual slam and 3D data modeling, the Iterative Closest Point method is a primary fundamental algorithm, and many technical fields have used this method. However, it relies on search methods that take a high search time. This paper solves this problem by applying an effective point cloud refinement method. And this paper also accelerates the point cloud registration process with an indexing scheme using the spatial decomposition method. Through some experiments, the results of this paper show that the proposed point cloud refinement method helped to produce better performance.

Optimal Network Defense Strategy Selection Based on Markov Bayesian Game

  • Wang, Zengguang;Lu, Yu;Li, Xi;Nie, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.13 no.11
    • /
    • pp.5631-5652
    • /
    • 2019
  • The existing defense strategy selection methods based on game theory basically select the optimal defense strategy in the form of mixed strategy. However, it is hard for network managers to understand and implement the defense strategy in this way. To address this problem, we constructed the incomplete information stochastic game model for the dynamic analysis to predict multi-stage attack-defense process by combining Bayesian game theory and the Markov decision-making method. In addition, the payoffs are quantified from the impact value of attack-defense actions. Based on previous statements, we designed an optimal defense strategy selection method. The optimal defense strategy is selected, which regards defense effectiveness as the criterion. The proposed method is feasibly verified via a representative experiment. Compared to the classical strategy selection methods based on the game theory, the proposed method can select the optimal strategy of the multi-stage attack-defense process in the form of pure strategy, which has been proved more operable than the compared ones.

Modified nonlinear force density method for form-finding of membrane SAR antenna

  • Xu, Rui;Li, DongXu;Liu, Wang;Jiang, JianPing;Liao, YiHuan;Wang, Jie
    • Structural Engineering and Mechanics
    • /
    • v.54 no.6
    • /
    • pp.1045-1059
    • /
    • 2015
  • Form-finding for cable-membrane structures is a delicate operation. During the last decades, the force density method (FDM) was considered to be an efficient method to address the problem. Many researchers were devoted to improving this method and proposed many methods such as natural force density method (NFDM), improved nonlinear force density method (INFDM), et al. In this paper, a modified nonlinear force density method (MNFDM) is proposed. In this method, the stresses of membrane elements were transformed to the force-densities of cable nets by an equivalent relationship, and then they can be used as initial conditions. By comparing with the forming finding results by using the FDM, NFDM, INFDM and MNFDM, it had demonstrated that the MNFDM presented in this paper is the most efficient and precise.

Methods of Defense DoS Attack by Traffic Metering and Controlling Technique in a Router (트래픽 제어 기법을 이용한 라우터에서의 서비스 거부 공격 방어 기법)

  • Lee, Ho-Gyun;Kim, Jeong-Nyeo
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2003.11c
    • /
    • pp.1985-1988
    • /
    • 2003
  • As the Distributed Denial of Service attack technique is getting smarter, defense method have been developed by various means. Existing defense method baseds on detection technique is not effective to DDoS attack. Because it depend on rule set that is used to detect attack and DDoS attack pattern has become very similar to real traffic pattern. So the rule set is not efficient method to find DDoS attack. To solve this problem, DDoS defense mechanism based on QoS technique has been suggested. In this paper, we summarize existing DDoS defense mechanism and focus on method based on QoS, and introduce a new DDoS defense framework.

  • PDF

Efficient Task-Resource Matchmaking Technique for Multiple/Heterogeneous Unmanned Combat Systems (다중/이종 무인전투체계를 위한 효율적 과업-자원 할당 기법)

  • Young-il Lee;Hee-young Kim;Wonik Park;Chonghui Kim
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.26 no.2
    • /
    • pp.188-196
    • /
    • 2023
  • In the future battlefield centered on the concept of mosaic warfare, the need for an unmanned combat system will increase to value human life. It is necessary for Multiple/Heterogeneous Unmanned Combat Systems to have suitable mission planning method in order to perform various mission. In this paper, we propose the MTSR model for mission planning of the unmanned combat system, and introduce a method of identifying a task by a combination of services using a request operator and a method of allocating resources to perform a task using the requested service. In order to verify the performance of the proposed task-resource matchmaking algorithm, simulation using occupation scenarios is performed and the results are analyzed.

HILS Technique based on Inertial Sensor Modeling for High Maneuvering Missiles (고기동 유도탄 모의비행시험 기법 밀 관성센서 모델링)

  • Kim, Ki-Seung;Yu, Myeong-Jong;Ra, Won-Sang;Lee, Sang-Woo;Kim, Young-Ju
    • Proceedings of the KIEE Conference
    • /
    • 2005.07d
    • /
    • pp.2540-2542
    • /
    • 2005
  • This paper proposed the new HILS technique called Injection Method for Inertial Sensor Verification of high maneuvering missiles. The performance of Inertial Sensor is verified by Injection Method and traditional FMS Method. After all, Injection Method for Inertial Sensor has capability for various scenario and critical condition test.

  • PDF

A Study on Transmission Signal Design Using DAC to Reduce IQ Imbalance of Satellite-Mounted Synthetic Aperture Radar Transmitter (위성 탑재 영상레이다 송신기의 IQ 불균형 저감을 위한 DAC를 이용한 송신 신호 설계 기법에 관한 연구)

  • Lee, Young-Bok;Kang, Tae-Woong;Lee, Hyon-Ik
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.25 no.2
    • /
    • pp.144-150
    • /
    • 2022
  • The on-board processor of satellite synthetic aperture radar(SAR) generates transmission signal by digital signal processing, converts it into an analog signal. At this time, the transmission signal generated from the baseband requires the frequency modulation to convert it to the high-frequency band in order to improve the stability. General frequency modulation method using local oscillator(LO) causes IQ imbalance due to phase error/magnitude error and these error reduce performance of SAR. To generate transmission signal without phase/magnitude error, this paper suggests design method of the frequency modulation method using digital to analog converter(DAC) at on-board SAR. For design, this paper analyzes the characteristic of DAC mode and uses pre-compensation filter. To analyze the proposed method performance, performance index are compared with IQ imbalance signals. This method is suitable for on-board SAR using fast sampling DAC and has the advantage of being able to solve IQ imbalances.

Analysis Method of Transmission Characterization for Multi-layered Composite Material Based on Homogenization Method

  • Hyun, Se-Young;Song, Yong-Ha;Jeoun, Young-Mi;Kim, Bong-Gyu
    • Journal of Aerospace System Engineering
    • /
    • v.15 no.6
    • /
    • pp.59-65
    • /
    • 2021
  • In this paper, the transmission characteristics of the multi-layered composite material with wire mesh and honeycomb core for aircraft applications have been analyzed with the proposed method. The proposed method converts the conductive wire mesh into effective layer, while for the dielectric honeycomb core, effective permittivity has been derived based on volume fraction with the proposed method. The proposed method has been verified through comparison with full-wave simulation and revealed excellent. In addition, the calculation time of the proposed method is a few order of magnitude faster in comparison with the full-wave simulation.

Development of the Information Security Methodology for Defense Organization (국방조직의 정보보호 평가 방법론 개발)

  • Cho, Sung Rim;Choi, In Soo;Park, Ji Hoon;Shin, Woo Chang
    • Journal of Information Technology Services
    • /
    • v.12 no.4
    • /
    • pp.77-90
    • /
    • 2013
  • As Cyber threats are rising, the scope of information Security (IS) is extending from technical protection of a single information system to organizational comprehensive IS capability. The ministry of National Defense (MND) has established the IS evaluation for defense organization in 'the Directive for Defense Informatization Affairs.' However, no information about an evaluation method, process and organization is provided. We surveyed information security management system (ISMS) and related best practices in public sector and other countries, and analysed the military information security affairs. Thus, this paper recommends the IS evaluation method and process. The trial IS evaluation is in progress this year and the MND will expand this IS evaluation to the entire organization.

Range-Doppler Clustering of Radar Data for Detecting Moving Objects (이동물체 탐지를 위한 레이다 데이터의 거리-도플러 클러스터링 기법)

  • Kim, Seongjoon;Yang, Dongwon;Jung, Younghun;Kim, Sujin;Yoon, Joohong
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.17 no.6
    • /
    • pp.810-820
    • /
    • 2014
  • Recently many studies of Radar systems mounted on ground vehicles for autonomous driving, SLAM (Simultaneous localization and mapping) and collision avoidance are reported. In near field, several hits per an object are generated after signal processing of Radar data. Hence, clustering is an essential technique to estimate their shapes and positions precisely. This paper proposes a method of grouping hits in range-doppler domains into clusters which represent each object, according to the pre-defined rules. The rules are based on the perceptual cues to separate hits by object. The morphological connectedness between hits and the characteristics of SNR distribution of hits are adopted as the perceptual cues for clustering. In various simulations for the performance assessment, the proposed method yielded more effective performance than other techniques.