• Fire Science and Engineering
• /
• v.26 no.1
• /
• pp.96-101
• /
• 2012

The buildings of domestic wear the upper floors and an underground in-depth reconciliation tendency to do and the possibility of fire occurrence at the time of formation accident is coming to be high. Therefore will be scattered to various place and is established and prevention of disaster information of the receiver which will integrate there is a necessity which will manage. In this paper away where each receiver is installed in the fire for the remote monitoring and controld able to connect to the Internet and fiber optic cable that can be networked fire receiver and control desk was constructed. Between each device can be used by the fire, and more depending on the status of monitoring and alarm, control and maintenance can be performed to develop an integrated management system. The system is evaluated by the criteria of the KFI, and for each segment of the signal propagation time to perform experiments confirmed the reliability of the performance.

• 전기의세계
• /
• v.19 no.3
• /
• pp.18-25
• /
• 1970

Chesin-1 telephone currently used in Korea is quite similar in design to early Japanese model of Type-4 telephone which is now being replaced by Type-600 having much improved characteristics. Chesin-1 telephone has a relatively high side-tone level, since the line impedance was taken as a purely resistive component for simplicity in the design of its transmission networks. To meet a current trend of using a smaller diameter of wire for telephone line, it is necessary to improve the present type which has a limited receiving efficiency. A new telephone set has been designed to have an amplifier and a R-C coupled side-tone balancing network. The set offers 8dB gain in the overall performance of transmitting and receiving without any unbearable side-tone disturbances. The paper describes both theoretical and experimental characteristics of the new set.

• International Journal of Computer Science & Network Security
• /
• v.21 no.6
• /
• pp.23-28
• /
• 2021

The article discusses the features of adaptation of the parameters of the physical layer of data transmission in self-organizing networks based on unmanned aerial vehicles operating in the conditions of "smart cities". The concept of cities of this type is defined, the historical path of formation, the current state and prospects for further development in the aspect of transition to "smart cities" of the third generation are shown. Cities of this type are aimed at providing more comfortable and safe living conditions for citizens and autonomous automated work of all components of the urban economy. The perspective of the development of urban mobile automated technical means of infocommunications is shown, one of the leading directions of which is the creation and active use of wireless self-organizing networks based on unmanned aerial vehicles. The advantages of using small-sized unmanned aerial vehicles for organizing networks of this type are considered, as well as the range of tasks to be solved in the conditions of modern "smart cities". It is shown that for the transition to self-organizing networks in the conditions of "smart cities" of the third generation, it is necessary to ensure the adaptation of various levels of OSI network models to dynamically changing operating conditions, which is especially important for the physical layer. To maintain an acceptable level of the value of the bit error probability when transmitting command and telemetry data, it is proposed to adaptively change the coding rate depending on the signal-to-noise ratio at the receiver input (or on the number of channel decoder errors), and when transmitting payload data, it is also proposed to adaptively change the coding rate together with the choice of modulation methods that differ in energy and spectral efficiency. As options for the practical implementation of these solutions, it is proposed to use an approach based on the principles of neuro-fuzzy control, for which examples of determining the boundaries of theoretically achievable efficiency are given.