• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.929-932
• /
• 2013

In preperation for the compulsory installation of VHF(Very High Frequency) wireless equipment and fishing vessel automatic identification system according to the revision of "The Ships Safety Act" and "Fishing Vessel act", Fishery Information & Communication Department of National Federation of Fisheries Cooperatives is building VHF communication network and automatic identification system for fishing vessel monitoring. This study suggests the protocol analysis for the calling of location requirement using DSC(Digital Selective Calling) function and show best way for fishing vessel automatic identification system. Also, it suggest way to realize fishing vessel monitoring system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2800-2805
• /
• 2013

In preperation for the compulsory installation of VHF(Very High Frequency) wireless equipment and fishing vessel automatic identification system according to the revision of "The Ships Safety Act" and "Fishing Vessel act", Fishery Information & Communication Department of National Federation of Fisheries Cooperatives is building VHF communication network and automatic identification system for fishing vessel monitoring. This study suggests the protocol analysis for the calling of location requirement using DSC(Digital Selective Calling) function and show best way for fishing vessel automatic identification system. Also, it suggest way to realize fishing vessel monitoring system.

• Proceedings of the KIEE Conference
• /
• 2002.07a
• /
• pp.560-562
• /
• 2002

This paper describes measurement and diagnosis methods for electromagnetic wave using a VHF(Very High Frequency) antenna. In the laboratory partial discharges are generated on a needle-plate and a plate-plate configuration. The detected electromagnetic wave is analyzed by FFT(Fast Fourier Transform). We propose a methode to classify creeping partial discharge and corona partial discharge that are detected in three frequency bands.

• Journal of Internet of Things and Convergence
• /
• v.10 no.4
• /
• pp.109-115
• /
• 2024

This paper proposes an interference recognition-based resource allocation (IaRA) scheme for very high frequency (VHF) data exchange-terrestrial (VDE-TER) to ensure the reliability of automatic identification system (AIS) message transmission in a coastal environment with dense vessels. To this end, IaRA conducts channel selection and slot allocation based on scheduling information obtained through monitoring VHF data exchange system (VDES) channels. The simulation results show that IaRA achieved an 8.79% higher packet delivery ratio (PDR) and a 9.69% lower channel interference ratio (CIR) compared to the VDE-TER resource allocation scheme of the existing VDES standard.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.4
• /
• pp.839-843
• /
• 2005

In this paper, wish to improve reception performance of general receiver manufacturing maritime broadband reception amplifier that can thread easily in VHF transmit-receive equipment into downsize, light weight, low-coat. Manufactured reception amplifier expressed Characteristic that improve reception sensitive 3dBm in $140MHz\~170MHz$ frequency band. Therefore, may use communications equipment that utilize VHF wide-band more efficiently. Also, practical use degree is considered to be very high because telecommunication of good quality is available.

• The Journal of the Acoustical Society of Korea
• /
• v.23 no.4E
• /
• pp.120-124
• /
• 2004

A new type of high frequency wideband ultrasonic transducer with a separation between a transmitter and a receiver was proposed and its characteristics were simulated using a PSpice model. The piezoelectric ceramic $PbTiO_{3}$ as a transmitter and the piezoelectric copolymer P(VDF- TrFE) as a receiver were used for high sensitivity and wide bandwidth, respectively. The characteristics of the focusing transducer with center frequency of approximately 35MHz fabricated in this study showed very wide bandwidth, which could give an axial spatial resolution better than $30{\mu}m$ in B-mode image for biological tissues.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.3
• /
• pp.246-252
• /
• 2013

This paper presents method to suppress signal interference by using the filter in the RF output stage of the radiation equipment as a way to avoid interference between the RF(Radio Frequency) equipment mounted on aircraft. Especially filter design to suppress harmonics of the radiation equipment and testing method to verify the filter's performance is presented. Filter was installed at RF output stage of U/VHF radio in order to prevent interference between U/VHF(Ultra/Very High Frequency) radio and data link system. Filter design and testing method in this paper will be able to give help in the design of aircraft equipments as a tool that can be used to establish measures for problem of interference in the aircraft.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.21 no.1
• /
• pp.15-22
• /
• 2013

In oceanic flight routes, HF radio and satellite data links have weather restrictions, long propagation delay and low data throughput. In this paper, we propose oceanic aeronautical communications scheme in the VHF band based on ad-hoc communication. The proposed scheme organizes autonomously a multi-hop network that is divided into multiple local network using aircraft to fly long-distance communication and supports a hybrid type of multiple access, which consists of random access and TDMA (Time Division Multiple Access) scheme. In addition, several algorithms to apply spatial reuse of transmission to multi-hop long range communication environments have been proposed. The proposed system proves performance improvement on delay time as an effective solution to communicate end-to-end on the oceanic flight routes and strengthens the reliability of oceanic aeronautical communication.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.20 no.3
• /
• pp.22-27
• /
• 2012

In oceanic flight routes, HF radio and satellite data links have been used for air-to-ground communication, but these systems have long propagation delay and low data throughput. In this paper, we propose a reliable system to overcome the weakness of current HF radio and satellite communication systems for oceanic aeronautical flight routes. The proposed scheme uses only one aeronautical VHF channel in multi-hop oceanic communication environments and supports a hybrid type of multiple access, which consists of random access and TDMA (Time Division Multiple Access) scheme. The proposed system improves performance on delay and throughput as an effective solution to communicate end-to-end on the oceanic flight routes and strengthens the reliability of oceanic aeronautical communication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.261-264
• /
• 2005

In this paper, wish to improve reception performance of general receiver manufacturing broadband reception amplifier that can thread easily in VHF transmit-receive equipment into downsize, light weight, low-cost. Manufactured reception amplifier expressed Characteristic that improve reception sensitive 3dBm in 140MHz ${\cdot}$ 170MHz frequency band. Therefore, may use communications equipment that utilize VHF wide-band more efficiently. Also, practical use degree is considered to be very high because telecommunication of good quality is available.