• Title/Summary/Keyword: communication networks

Search Result 5,470, Processing Time 0.029 seconds

A study on the implementation of the wireless video security system (무선 영상보안시스템 구현에 관한 연구)

  • Kim, Young-Min;Kim, Myeong-Hwan;Kim, Sun-Hyung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.7 no.1
    • /
    • pp.99-104
    • /
    • 2012
  • In this paper, implementation of a wireless video security system relates to a situation outside of using infrared sensors to detect changes when using Zigbee network security in the area of the sensor sends information to the server. The server can judge the situation if an emergency situation through the IP network security camera shot of the area to be transferred command to pantilte. The camera images and information in the security area, sent to administrator's smartphone users to control the camera can see the situation and More than a small video security system was designed so that user can monitor the security zone. Finally, for real-time to identify and respond to emergency situations based on the available wireless networks for video surveillance systems were verified through research and implementation.

  • PDF

Development of real-time monitoring system using wired and wireless networks ina full-scale ship

  • Paik, Bu-Geun;Cho, Seong-Rak;Park, Beom-Jin;Lee, Dong-Kon;Bae, Byung-Dueg
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.2 no.3
    • /
    • pp.132-138
    • /
    • 2010
  • In the present study, the real-time monitoring system is developed based on the wireless sensor network (WSN) and power line communication (PLC) employed in the 3,000-ton-class training ship. The WSN consists of sensor nodes, router, gateway and middleware. The PLC is composed of power lines, modems, Ethernet gateway and phase-coupler. The basic tests show that the ship has rather good environments for the wired and wireless communications. The developed real-time monitoring system is applied to recognize the thermal environments of main-engine room and one cabin in the ship. The main-engine room has lots of heat sources and needs careful monitoring to satisfy safe operation condition or detect any human errors beforehand. The monitoring is performed in two regions near the turbocharger and cascade tank, considered as heat sources. The cabin on the second deck is selected to monitor the thermal environments because it is close to the heat source of main engine. The monitoring results of the cabin show the thermal environment is varied by the human activity. The real-time monitoring for the thermal environment would be useful for the planning of the ventilation strategy based on the traces of the human activity against inconvenient thermal environments as well as the recognizing the temperature itself in each cabin.

An Efficient Error Concealment Algorithm using Adaptive Selection of Adjacent Motion Vectors (주변 움직임 벡터의 적응적 선택을 이용한 효율적인 에러은닉 알고리즘)

  • Lee Hyun-Woo;Seong Dong-Su
    • The KIPS Transactions:PartB
    • /
    • v.11B no.6
    • /
    • pp.661-666
    • /
    • 2004
  • In the wireless communication systems, transmission errors degrade the reconstructed image quality severely. Error concealment in video communication is becoming increasingly important because transmission errors can cause single or multiple loss of macroblocks in video delivery over unreliable channels such as wireless networks and internet. Among various techniques which can reduce the degradation of video quality, the error concealment techniques yield good performance without overheads and the modification of the encoder. In this paper, lost image blocks can be concealed with the OBMC(Overlapped Block Motion Compensation) after new motion vectors of the lost image blocks are allocated by median values using the adaptive selection with motion vectors of adjacent blocks. We know our algorithm is more effective in case of continuous GOB loss. The results show a significant improvement over the zero motion error concealment and other temporal concealment methods such as Motion Vector Rational Interpolation or Median+OBMC by 3dB gain in PSNR.

A base technical development and standardization plan of Customer Premises (21C 댁내 정보화 기반조성을 위한 구내통신선로설비 기반기술개발 및 표준화 계획)

  • 최세하
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.2 no.4
    • /
    • pp.495-509
    • /
    • 1998
  • Telecommunication network has been constructed and developed to provide voice. data, and simple image communication service in accordance with the demand increase and the various service tendency according to the growth of social economy It is expected that various multimedia services are transmitted and received through a telecommunication media. First of all, for the sake of realization of these schemes in house, it is essential to make the customer premises networks to be higher level. Especially, the demand increment of customer services and the improvement of technology would be expected to be a result of a main-stream strategic industry. This paper briefly describes investigation results concerning technical development and standardization trends of advanced nation, and introduce technical development and standardization plan which the Government is presently carrying out. We also proposes the schedule of technical development and standardization plan related to international standard.

  • PDF

SNS disclosure of personal information in M2M environment threats and countermeasures (M2M 환경에서의 SNS 개인정보 유출 위협 및 대응방안)

  • Go, Jun-Young;Lee, Keun-Ho
    • Journal of the Korea Convergence Society
    • /
    • v.5 no.1
    • /
    • pp.29-34
    • /
    • 2014
  • It appeared with the development of IT skills to help the social network SNS(Social Network Service) on the online form. Many people around the world and in the business environment changes is the emergence of social networks are bringing. And the rapid development of the idea, but are insignificant for the security threats that are used by many people in many companies, and social network services. In addition, although it is true that this connection is increased from the number of mobile machines to the development of M2M, that is not recognized for that vulnerability. To evaluate and identify vulnerabilities against security threats and countermeasures for the SNS access the social network on the M2M After looking for privacy and in the present.

A Design and Implementation of Dual-band Monopole Antenna with DGS (DGS를 이용한 이중 대역 모노폴 안테나의 설계 및 제작)

  • Choi, Tea-Il;Kim, Jeong-Geun;Yoon, Joong-Han
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.11 no.9
    • /
    • pp.841-848
    • /
    • 2016
  • In this paper, a microstrip-fed dual-band monopole antenna with DGS(: Defected Ground System) for WLAN(: Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a microstrip-fed structure, and composed of two strip lines and DGS structure and then designed in order to get dual band characteristics. We used the simulator, Ansoft's High Frequency Structure Simulator(: HFSS) and carried out simulation about parameters W2, L10, W3, and DGS to get the optimized parameters. The proposed antenna is made of $21.0{\times}36.0{\times}1.6mm3$ and is fabricated on the permittivity 4.4 FR-4 substrate. The experiment results are shown that the proposed antenna obtained the -10 dB impedance bandwidth 700 MHz(2.10~2.80 GHz) and 1,780 MHz(5.02~6.80 GHz) covering the WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required dual-band(2.4GHz band/5.0GHz band), respectively.

Design of Circular Ring Antenna with Half-Circular Strip for WLAN/WiMAX Applications (WLAN/WiMAX 시스템에 적용 가능한 반원 스트립 구조를 갖는 원형 링 안테나의 설계)

  • Yoon, Joong-Han
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.9 no.4
    • /
    • pp.417-424
    • /
    • 2014
  • In this paper, a dual-band circular ring monopole antenna with semi-circular strip for WLAN(Wireless Local Area Networks)/WiMAX(World interoperability for Microwave Access) applications. The proposed antenna is based on a planar monopole design, and composed of half circular strip for dual-band operation which cover WLAN and WiMAX frequency bands. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is fabricated. The numerical and experiment results demonstrated that the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are obtained for WLAN/WiMAX frequency bands.

Transmission Performance of Lattice Structure Ad-Hoc Network under Intrusions (침해가 있는 격자구조 애드-혹 네트워크의 전송성능)

  • Kim, Young-Dong
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.9 no.7
    • /
    • pp.767-772
    • /
    • 2014
  • As temporary network, ad-hoc network has been effected by structures and implemented environments of networks. In this paper, transmission performance of lattice structure ad-hoc network, which is expected to use in sensor network and IoT(Internet of Things), is analyzed in point of intrusions and countermeasure for intrusion is suggested. In this paper, computer simulation based on NS-2 is used for performance analysis, VoIP(Voice over Internet Protocol) as a widely used service is chosen for performance measure. MOS(Mean Opinion Score) and call connection rate is used as performance parameter. As results of performance analysis, it is shown that for MOS, random network is better then lattice network at intrusion environments, but for call connection rate, lattice network is better then random network.

Study on Cochlodinium polykrikoides Red tide Prediction using Deep Neural Network under Imbalanced Data (심층신경망을 활용한 Cochlodinium polykrikoides 적조 발생 예측 연구)

  • Bak, Su-Ho;Jeong, Min-Ji;Hwang, Do-Hyun;Enkhjargal, Unuzaya;Kim, Na-Kyeong;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.14 no.6
    • /
    • pp.1161-1170
    • /
    • 2019
  • In this study, we propose a model for predicting Cochlodinium polykrikoides red tide occurrence using deep neural networks. A deep neural network with eight hidden layers was constructed to predict red tide occurrence. The 59 marine and meteorological factors were extracted and used for neural network model training using satellite reanalysis data and meteorological model data. The red tide occurred in the entire dataset is very small compared to the case of no red tide, resulting in an unbalanced data problem. In this study, we applied over sampling with adding noise based data augmentation to solve this problem. As a result of evaluating the accuracy of the model using test data, the accuracy was about 97%.

Improved BER Performance of Non-Orthogonal Multiple Access System for Interactive Mobile Users: Maximum Likelihood Detection Perspective (상호작용 이동통신 사용자에 대한 비직교 다중접속 시스템의 BER 성능 향상: ML 검출 관점)

  • Chung, Kyu-Hyuk
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.15 no.5
    • /
    • pp.865-872
    • /
    • 2020
  • In the fifth generation (5G) mobile networks, non-orthogonal multiple access (: NOMA) has been considered as a promising technology, to increase the channel capacity. In NOMA, the multiple users share the channel resources and multiplex simultaneously. Recently, for the stronger channel user, it was reported that the bit-error rate (: BER) performance with interactive mobile users is degraded, compared to the BER of non-interactive users. In this paper, in order to improve such degraded BER performance, we propose the maximum-likelihood (: ML) receiver. First, the closed-form expression for the BER of the ML receiver is derived, and then it is shown that the BER of the ML receiver is improved, compared with the BER of the ideal perfect successive interference cancellation (: SIC) receiver. Additionally, based on the analytical expression, Monte Carlo simulations validates the above-mentioned results.