On the capacity of the state‐dependent interference relay channel

This paper considers the state‐dependent interference relay channel (SIRC) in which one of the two users may operate as a secondary user and the relay has a noncausal access to the signals from both users. For discrete memoryless SIRC, we first establish the achievable rate region by carefully merging Han‐Kobayashi rate splitting encoding technique, superposition encoding, and Gelfand‐Pinsker encoding technique. Then, based on the achievable rate region that we derive, the capacity of the SIRC is established in many different scenarios including (a) the weak interference regime, (b) the strong interference regime, and (c) the very strong interference regime. This means that our capacity results contain all available known results in the literature. Next, the achievable rate region and the associated capacity results are also evaluated in the case of additive Gaussian noise. Additionally, many numerical examples are investigated to show the value of our theoretical derivations.     

Co-Channel Interference of Spread Spectrum Systems in a Multiple User Environment

This paper considers the mutual interference problem of several users employing the same spread spectrum technique in selected multiple user environments. The spread spectrum techniques consist of pseudo noise (PN), time division multiple access/PN, synchronous and asynchronous frequency hopping (FH). The environment consists of a desired transmitter-receiver pair located in an area where there areMinterfering users distributed in accordance with a specified probability density function. Both coherent phase-shift-keyed-and noncoherent frequency-shift-keyed modulations are considered. The general relationship between the probability of bit error of PN and FH systems is derived which is independent of the signal modulation and distribution of users. The degradation of the communication system performance (average probability of bit error) of the desired link as a function of the total number of interfering users within the considered area is investigated. The analysis shows that the mutual interference problem is less severe with users employing synchronous FH than with the other spread spectrum techniques. The comparison between asynchronous FH and PN is highly dependent on the relative location of interferers to the desired link and the time duty factor of the hopping.     

Investigation of microstructure and wear behaviors of al matrix composites reinforced by carbon nanotube

In this study, the effect of CNT amount in Al-CNT composites produced by adding carbon nanotube (CNT) to 7075 Al alloy in various amounts on microstructure and wear behaviors of aluminum matrix composites was investigated. CNT was added to 7075 Al alloy powder at five different amounts. The powders were mechanically milled for 2 hours. Mechanical milled powders were cold pressed and then pre-shaped by hot pressing. Pre-shaped samples were sintered for 1 hour under 10^?6 millibar in 580°C. Microstructure examinations, hardness measurements, and wear tests were carried out. The results show that CNT's in the microstructure were agglomerated as nanotube amount increases and there was no uniform distribution. The highest hardness value was obtained in AMC reinforced with 1% CNT while it is seen that hardness of the composite decreases and weight loss increases as CNT amount increases.     

Optimization of citrus peels D-limonene extraction using solvent-free microwave green technology

Attention is presently drawn to the development of a new and green alternative technique for the extraction of essential oil from citrus plant materials. This study was aimed at the extracting essential oil from orange and lemon peels using solvent-free microwave method. This process uses microwave-assisted hydro-diffusion technique to extract essential oil from citrus peels. Response surface methodology was used to investigate the effect of microwave power (200–1,000?W) and extraction time (10–40?min) on the essential oil yield. The oil extracted was characterized using Fourier transform infrared radiation (FTIR) and Gas chromatography–mass spectrometry analysis to determine the functional groups and chemical components present, respectively. The optimum yield of extract from orange and lemon peels were 3.7 and 2.0%, respectively at corresponding power of 1,000?W and time of 10?min. The analysis of variance results showed that the resulting models for both orange and lemon peels were significant and microwave power had greater influence on the extraction processes at both linear and quadratic levels. The FTIR analysis revealed prominent functional groups of alkenes that majorly constitute limonene compound at 1,642 and 1,643?cm^?1 for orange and lemon peels, respectively. The present process permits fast and efficient extraction, avoids water and solvent consumption, and allows substantial energy savings.     

An Optimal Algorithm for Resource Allocation in D2D Communication

The number of mobile devices accessing wireless networks is skyrocketing due to the rapid advancement of sensors and wireless communication technology. In the upcoming years, it is anticipated that mobile data traffic would rise even more. The development of a new cellular network paradigm is being driven by the Internet of Things, smart homes, and more sophisticated applications with greater data rates and latency requirements. Resources are being used up quickly due to the steady growth of smartphone devices and multimedia apps. Computation offloading to either several distant clouds or close mobile devices has consistently improved the performance of mobile devices. The computation latency can also be decreased by offloading computing duties to edge servers with a specific level of computing power. Device-to-device (D2D) collaboration can assist in processing small-scale activities that are time-sensitive in order to further reduce task delays. The task offloading performance is drastically reduced due to the variation of different performance capabilities of edge nodes. Therefore, this paper addressed this problem and proposed a new method for D2D communication. In this method, the time delay is reduced by enabling the edge nodes to exchange data samples. Simulation results show that the proposed algorithm has better performance than traditional algorithm.     

Performance of SOR methods on modern vector and scalar processors

The building-cube method (BCM) is a new generation algorithm for CFD simulations. The basic idea of BCM is to simplify the algorithm in all stages of flow computation to achieve large-scale simulations. Calculation of a pressure field using the Successive Over Relaxation (SOR) method consumes most of the total execution time required for BCM. In this paper, effective implementations on modern vector and scalar processors are investigated. NEC SX-9 and Intel Nehalem-EX are the latest vector and scalar processors. Those processors have much higher peak performances than their previous-generation processors. However, their memory bandwidth improvement cannot catch up with the performance improvement of processors. This is the so-called memory wall problem. In our paper, we discuss optimization techniques for implementation of the SOR method based on architectural characteristics of these modern processors, and evaluate their effects on the sustained performances of these processors for BCM.     

Effect of carbohydrate supplementation provided through drinking water during feed withdrawal on meat and liver colours in broilers

BACKGROUND: The effect of saccarose supplementation provided through drinking water during feed withdrawal on meat and liver colour was investigated in a total of 50 broilers (five floor pens with 10 broilers) at 43 days. Treatments consisted of: (1) full‐fed control broilers fed the standard broiler diet and water for the full 10 h (control); (2) fasted broilers receiving only water (FW); (3) 1 g (0.01SW); (4) 2 g (0.02SW); and (5) 3 g (0.03SW) saccarose L^?1 supplemented water for the 10 h. The CIE colour values representing lightness (L*), redness (a*), and yellowness (b*) were measured on raw livers, breast and thigh meats. RESULTS: Full‐fed broilers had lower dressing percentage, higher abdominal fat and liver yield and lighter thigh meat coloration than the FW birds (P < 0.05). The 0.02SW and 0.03SW resulted in live shrinks that were lower (P < 0.05) than those found in FW broilers. The 0.02SW and 0.03SW resulted in liver colours that were lighter than those found in FW and 0.01SW birds but darker than from control birds (P < 0.05). CONCLUSION: It was concluded that saccarose supplementation during feed withdrawal appears to have a measurable impact on live shrink, and lightness of liver and thigh meat colour in broilers. Copyright © 2007 Society of Chemical Industry