In this article, an attempt has been made to estimate the amount of sound transmission loss in a flat oval Channel by applying the approach of statistical energy analysis. Correct estimation of sound transmission loss in an air conditioning Channel is of great importance due to the harmful effects of noise pollution in the environment on human health. Simulation with the statistical energy analysis method is a powerful approach to estimate sound and vibration in problems in which we deal with complex and multi-part systems; is considered. In this method, first, a system is divided into several subsystems, and then by writing a matrix equation that includes the energy exchanges between subsystems and energy loss coefficients; It is investigated from the perspective of vibration and sound estimation.On average, the model presented in this research is able to estimate the sound transmission loss in different dimensions of the air conditioning Channels according to the experimental results in the accuracy range of ± 2.5 dB. Considering that it seems that the results obtained from modeling with this method are in good agreement with the experimental data; The results of this research can be used as an efficient approach to estimate noise in oval shaped Channels stretched in different lengths.

The shopping experience in Omni-Channel distributions is influenced by the physical environment of the buyer, delivery time, and the cost of production to distribution of the goods which have a significant impact on customer loyalty and customer satisfaction. This study presents a system dynamics approach to identify the variables affecting the three aspects of customer satisfaction, cost, and delivery time, as well as the relationships among these variables in omni-Channel distribution. By reviewing previous studies and expert opinions identifying important variables, followed by generating different scenarios in the Vensim software, the optimal values of the important variables are estimated. It is observed that by approaching the values of the fourth scenario – increase in the amount of market competitiveness indices, customer referral rate, marketing costs, technology etc. and decrease in the maintenance costs – the highest customer satisfaction and the lowest cost and delivery time can be achieved.

In this paper the secrecy problem in the cognitive state-dependent interference Channel is considered. In this scenario we have a primary and a cognitive transmitter-receiver pairs. The cognitive transmitter has the message of the primary sender as side information. In addition, the state of the Channel is known at the cognitive encoder. Hence, the cognitive encoder uses this side information to cooperate with the primary transmitter. The message of the cognitive encoder must be secret at the primary receiver, i.e., the primary receiver act as an eavesdropper for the cognitive transmitter. An achievable rate region and an outer bound on the rate region in this Channel are derived. The results are extended to the previous works as special cases.

In this paper optimization of frequency offset estimation technique based on Channel estimation, which is desirable for frequency selective Channels and hasfast convergence speed, for using in HF Channel is addressed. Because of time variations coherence time in HF Channel is short, which leads to a severe degradation in the performance of above technique in this Channel. An optimization of said technique is proposed in which after removing coarse frequency offset estimation and knowing residual frequency offset range, incorrect estimations can be removed and others can be averaged to give final correct estimate. Simulation is conducted underChannel parameters with respect to MIL-STD-188-110B. the results show that proposed optimization result in improved performance of frequency offset estimation technique based on Channel estimation.

We study an entangled two-mode coherent state within the framework of 2×2-dimensional Hilbert space. We investigate the problem of quantum teleportation of a superposition coherent state via an entangled coherent Channel. By three different measures with the titles ``minimum assured fidelity (MASF)” , ``average teleportation fidelity” and ``optimal fidelity (f)” we study the quality of this kind of teleportation. Decoherence properties of the entangled coherent state due to Channel losses are analysed. For a symmetric noise Channel, the degradation of optimal fidelity and degree of entanglement are calculated. Also by two different measures with the titles ``concurrence” and ``entanglement of formation” we study the amount of entanglement of a decohered quantum Channel and discuss its details. We demonstrate that entanglement of the decohered entangled coherent state is reduced but not throughly lost. Finally we find that the optimal fidelity of the decohered entangled coherent state is more than the classical limit and the decohered entangled coherent state may be useful for quantum teleportation.

The progress of the technology in the recent decades has caused the video transmission by communication Channels to meet high demands. Therefore, many methods have been proposed to improve the quality of the video under Channel errors. The aim of this paper is to increase the Peak Signal to the Noise Ratio (PSNR) for video reconstructed by the receiver. This is achieved by increasing Channel encoder rate but in constant transmission rate. In the proposed method the video frames’ parts containing more energy are coded by the local Channel coding inside the source encoder. Then, the resulted data is embedded in the low power frames’ parts. The proposed method is able to increase the Channel coding rates without increasing the amount of the information for any frame. This method provides more robustness for video frames against Channel errors. The proposed method is tested for different source coding rates and several Signals to Noise Ratio (SNRs) for Channel and the obtained results are compared with a new method.