Polar codes, that have been recently introduced by Arikan, are one of the first codes that achieved the capacity for vast numerous channels and they also have low complexity in symmetric memoryless channels. Polar codes are constructed based on a phenomenon called channel polarization. This paper discusses relay channel polarization in order to achieve the capacity and show that if inputs of two different relay channels follow the Arikan polarization structure, then they will be categorized as good and bad relay channels. Also, it has been shown that the eencoding and decoding complexity for these codes is O(N logN ), N is the code-length, and their error probability is O(2 (N ) )   like the Arikan's work, β is a number between [0, 0. 5]. In order to validate our construction of polar codes for relay channels, some numerical examples for this idea have been presented. Also, the efficiency of this construction for decode-and-forward and compressand-forward relaying strategies have been analyzed by using simulation results for finite block length in relay channels with orthogonal receiver.

In this study, we introduce a new two-way relay channel and obtain an inner bound and an outer bound for the discrete and memoryless multiple access relay channels with receiver-source feedback via two-way relay channel in which end nodes exchange signals by a relay node. And we extend these results to the Gaussian case. By numerical computing, we show that our inner bound is the same with one obtained by Hou-Koetter-Kramer, for the channel with relay-source feedback.

Extensive damages in welded unreinforced flange (WUF) connections in 1994 Northridge earthquakes has led to the idea of using reduced beam section (RBS) connections and Drilled Flange (DF) connection to prevent brittle failure modes in welded joints. In this paper, the seismic behavior of DF moment resisting connection with slot holes as an easy-to-construct method for DF connection in seismic regions was investigated. DF connection is made by drilling at top and bottom beam flange along beam main axis to establish intentional weak point to reduce stress concentration at beam to column flange welded connection. In this investigation, Finite Element models which were validated with previous experiments were utilized to consider the effect of slot holes compared to circular holes on rupture potential of beam to column welded connection. The utilized FE models of DF connection with various geometric properties and different panel zone strength ratios were developed to investigate the optimum slot hole configuration and reduce the rupture potential at CJP groove weld. The results showed that the optimum drilled slot holes is able to shift the plastic strain at beam to column welded connection having the ratio of slot hole length to hole diameter (L/D) by up to 2. Using the latter holes configuration, the plastic strain at beam to column weld connection and around the holes decreases up to 28 and 70% respectively compared to corresponding values of DF connection with circular holes.

In order to evaluate the effect of irrigation regimes on yield and growth parameters of cumim [Cuminum cyminum L.] an experiment was implemented in Mashhad during the years 1998-2000. Six irrigation treatments were used as; T1: No irrigation during growing period (rainfed). T2: One irrigation during the flowering stage, T3: One irrigation during the seed formation T4: Tow irrigation during the growing season: one at the flowering stage and one at the seed formation, T5: Three irrigation during the growing season: one after germination, one at flowering and one at seed formation stage, and T6: full irrigation during the growing season. During The growing season, treatments of rainfed and full irrigation received 190 mm and 350 mm of water respectively. The resuets showed that by reducing numbers of irrigation in various treatments, plant water potential also decreased. It reached to-30 bars without showing any sign of witting in T1 as compared to-15 bars at T6-Seed yield the number of umbells per plant and the number of seeds per umbeI1swere not significantly different at 5 percent level of significance. However, treatment T6, showed to have the least weight or 1000 seeds and harvest index and highest total biomass. Differences between Height of 1000 seeds of 11 and harvest index in T3. T4, T5 and total biomass of T1, T2, T3, T4 with T6 were significantly different at 5 percent level. The overall results of one year experiment showed hat in Mashhad climatic condition, cumin doesn't need to be irrigated in normal years.

In this paper, an Unmanned Aerial Vehicle (UAV) assisted cooperative communication system is studied, wherein a source transmits information to the destination through an energy harvesting decode-and-forward UAV. It is assumed that the UAV can freely move in between the source-destination pair to set up line of sight communications with both nodes. Since the battery of the UAV may be limited, it can harvest energy from the received signal by power splitting technique to be able to perfectly transmit data to the destination. Therefore, we study throughput maximization problem for multiple time slots data transmission through the cooperative energy harvesting UAV.  To maximize the throughput, optimal power allocation at the source and the UAV and power splitting ratio at the UAV are studied over each time slot in presence of energy-causality constraints at the UAV. Finally, numerical results are presented to analyze the spectral and energy efficiency of the proposed system, and effects of optimal power allocations and power splitting ratio.  The results indicate that by utilizing optimal resource allocations at the source and the UAV, and utilizing Simultaneous Wireless Information and Power Transfer (SWIPT), significant throughput improvement is achieved compared to those without optimal resource allocation or SWIPT. All of static UAV scenarios (i.e., the maximum throughput between the source and the destination) increases, while there is no need to increase the battery capacity of the UAV.