scholarly journals Targeting parent trust to enhance engagement in a school–home communication system: A double-blind experiment of a parental wise feedback intervention.

2019 ◽  
Vol 34 (4) ◽  
pp. 421-432
Author(s):  
Alaa K. Houri ◽  
Andrew J. Thayer ◽  
Clayton R. Cook
2022 ◽  
Author(s):  
Pingyue Yue ◽  
Jianping An ◽  
Jiankang Zhang ◽  
Gaofeng Pan ◽  
Shuai Wang ◽  
...  

<div>In view of the development status of the security of LEO satellite communication system, a comprehensive review, induction, and summary is carried out.<br></div>


2019 ◽  
Vol 55 ◽  
pp. 275-284 ◽  
Author(s):  
Jin-Taek Hwang ◽  
Jung Min Cho ◽  
In Hye Jeong ◽  
Jeong-yong Lee ◽  
Ki-Chan Ha ◽  
...  

2017 ◽  
Vol 13 (1) ◽  
pp. 57
Author(s):  
Nasaruddin Nasaruddin ◽  
Rony Kurnia ◽  
Ramzi Adriman

One of effective diversity techniques to combat fading on wireless channel is a cooperative communication system in which a source sends information through several relays and then forward it to a destination. A cooperative communication system has shown increased the system performance and reduced the energy consumption. However, it depends on the used relay mechanism that is relay protocols such as quantize and forward (QF) and amplify and forward (AF). In the previous research, energy efficiency of AF relay has investigated for a single-relay cooperative system, but multi-relay is more practical. Therefore, this research focuses on power efficiency in multi-relay cooperative communication system using QF protocol. The research method used is mathematical analysis and computer simulation for outage probability and power efficiency in the multi-relay QF. Simulation result found that multi-relay QF system could provide a high power efficiency, but the efficiency is reduced when the distance ratio increases. Power efficiency can be increased by adding the number of relays in the system. A comparison of power efficiency for QF and AF protocols has simulated, in which power efficiency of multi-relay QF is higher than that of multi-relay AF at distance ratio and power transmit. Thus, multi-relay QF system can provide high performance and power efficiency in the cooperative communication system.


2020 ◽  
Vol 24 (06) ◽  
pp. 42-56
Author(s):  
Hayder F. Fahad ◽  
◽  
Fadhil S. Hassan ◽  

Based on Orthogonal Chaotic Vector Shift Keying (OCVSK) system and Multilevel Code-Shifted Differential Chaos Shift Keying (MCS-DCSK) system, a new Multilevel Code-Shifted Differential Chaos Shift Keying (OMCS-DCSK) modulation system is proposed and designed in this paper. New orthogonal chaotic signal sets are generated using Gram-Schmidt algorithm and Walsh code function then these signals are used for bearing information bits to achieve higher data rate and better bandwidth efficiency compared with the conventional DCSK communication system. The bit error rate (BER) analysis of the OMCS-DCSK system over additive white Gaussian noise (AWGN) and multipath Rayleigh fading channel is derived and compared with the simulation results. Also, the spectral and complexity analysis of the system are presented and compared with the conventional DCSK systems. The results show that the proposed system outperforms OCVSK and MCS-DCSK in BER performance and spectral efficiency


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