A Review of Transmission Rate over Wireless Fading Channels: Classifications,Applications, and Challenges

To address the explosive traffic demands, the capacity of the fading channel is increasingly becoming a prime concern in the designing of the wireless communication system. The channel capacity is an extremely important quantity, since it allows the transmission of the data through the channel with an arbitrarily small probability of error. In other words, capacity dictates the maximum rate of information transmission, called as ‘capacity’ of channel, determined by the intrinsic properties of the channel and is independent of the content of the transmitted information. In this paper, we present a comprehensive survey of the existing work related to the channel capacity model over various fading channels. With an elaborated explanation of the theory of channel capacity, definitions of channel capacity based on the channel state information are reviewed. To compliment this, review of the technique to enhance the channel capacity is discussed and reviewed. An effective capacity model to overcome the channel capacity limitation is also explained. Furthermore, as the secure transmission of data is of utmost importance, to address this physical layer security model is also reviewed. We also summarize the work related to channel capacity in various types of wireless networks. We finally cover the future research directions, including less explored aspects of the channel capacity that can be studied to design efficient communication systems.

     

Designing and fabrication of phenothiazine and carbazole based sensitizers for photocatalytic water splitting application

In the present work, we have designed and synthesized two carbazole and phenothiazine donor moieties based metal-free organic sensitizers and their codes are WCBZ2 and WPTZ2 respectively. These sensitizers have been used for photocatalytic hydrogen (H₂) evaluation application. The sensitizers exhibit good light absorption capability and electrochemical properties as well. For increasing water splitting capacity, incorporate platinum salt on TiO₂ semiconductor photoanode was performed and compared hydrogen evolution with pure TiO₂ photoanode. We have also studied the influence of the sensitizer's concentration and the effect of pH of the medium was explored. Using a theoretical measurement optimized both the synthesized dimer dyes structure geometry and the calculated their HOMO-LUMO energy level. Here also reported optimized pH and concentration of sensitizers in the reaction medium and found that the high hydrogen generation efficiency from water splitting is 138.3 μmol (348 TONs) by the WPTZ2 dye.     

Annealing behaviour of electron-beam deposited tin dioxide films

The sheet resistivity of tin dioxide films deposited by electron-beam evaporation has been studied during annealing, both as a function of time and temperature. The annealing behaviour of SnO₂ films under the above two different conditions is consistent. A qualitative interpretation has been given for the decrease and the minimum observed in the resistivity. The increase in resistivity has been confirmed by scanning-electron micrographs. The films were also characterized by x-ray diffractometry.     

Reno-colo-cutaneous fistula. A case report

Reno-colo-cutaneous fistula due to genito-urinary tuberculosis is extremely rare. We describe one such case which was successfully managed by single stage surgery (nephroureterectomy, fistulectomy and primary repair of colon) and anti-tubercular treatment.     

Adsorptive recovery of water soluble essential oil components

Many essential oils are produced by the process of steam distillation. During this process valuable oxygenated components of the oil which have relatively higher solubility in water are preferentially lost in the distillate water. This loss is directly reflected in a lower yield and poor quality of the oil. Adsorption is extensively used for recovery of such valuable organics from dilute aqueous streams. This paper describes a preliminary study on the feasibility of adsorptive recovery. The following synthetic polymeric adsorbents were used in this work: Amberlite XAD-2, XAD-4 and XAD-7. Equilibrium and column exahaustion studies were carried out for the adsorption of phenyl ethyl alcohol (PEA), linalool (LL) and eugenol (EG) and also of mixtures of PEA and LL, and EG and LL from dilute aqueous solutions. The results indicate that XAD-4 is a relatively better adsorbent for all the three solutes studied.     

Blockchain-Based Security Enhancement and Spectrum Sensing in Cognitive Radio Network

Wireless Personal Communications - Biometric systems based on feature extraction from speech signals are extensively deployed in different security systems. This work presents a secure speaker...     

Experimental analogy of different texture feature extraction techniques in image retrieval systems

Content based image retrieval (CBIR) is an extrusive technique of retrieving the relevant images from vast image archives by extracting their low level features. In this research paper, the pursuance of five most prominent texture feature extraction techniques used in CBIR systems are experimentally compared in detail. The main issue with the CBIR systems is the proper selection of techniques for the extraction of low level features which comprises of color, texture and shape. Among these features, texture is one of the most decisive and dominant features. This selection of features completely depends upon the type of images to be retrieved from the database. The texture techniques explored here are Grey level co-occurrence matrix (GLCM), Discrete wavelet transform (DWT), Gabor transform, Curvelet and Local binary pattern (LBP). These are experimented on three touchstone databases which are Wang, Corel-5 K and Corel-10 K. The chief parameters of CBIR systems are evaluated here such as precision, recall and F-measure on all these databases using all the techniques. After detailed investigation it is figured out that LBP, GLCM and DWT provide highlighted and comparable results in all these datasets in terms of average precision. Besides practical implementation, the précised conceptual examination of these three texture techniques is also proposed in this article. So, this analysis is extremely beneficial for selecting the appropriate feature extraction technique by taking into consideration the experimental results along with image conditions such as noise, rotation etc.

     

Phonon dispersion and specific heat in <Emphasis Type="Italic">trans</Emphasis> 1,4, poly (2,3-dimethylbutadiene)

A comprehensive study of the normal modes and their dispersion for trans 1,4-poly (2,3 dimethylbutadiene) is described in the reduced zone scheme using Wilson’s GF matrix method as modified by Higg’s for an infinite polymeric chain. Urey Bradley force field is obtained by least square fitting of the observed IR and Raman bands. Optically active frequencies corresponding to the zone center and zone boundary are identified and discussed. Some of the characteristic features of dispersion curves are repulsion accompanied by exchange of character and Von Hove type singularities. The evaluation of normal modes and their dispersion has been taken to logical conclusion by calculating the heat capacity as a function of temperature. Specific heat has been obtained from dispersion curves via density of states in the range 10–400 K using Debye’s relation. The predictive values of specific heat show a typical variation for an one dimensional polymeric system.     

Revisiting Heat Capacity of Bulk Polycrystalline YBa2Cu3O7−δ

In this letter, we present the superconducting property characterization of a phase pure, reasonably good quality YBa₂Cu₃O_7?δ sample. Studied compound is crystallized in orthorhombic Pmmm space group with lattice parameters a, b, and c being 3.829(2), 3.887(1) and 11.666(3) Å, respectively. Bulk superconductivity is observed below 90 K as evidenced by resistivity and dc/ac magnetization measurements. The resistivity under magnetic field (ρTH) measurements showed clearly both the intra-grain and inter-grain transitions, which are supplemented by detailed (of varying frequency and amplitude) ac susceptibility studies as well. The upper critical field at 0 K, i.e. H _c2(0) being determined from ρTH measurements with 50 % criteria of resistivity drop, is ～70 T. Studied polycrystalline YBa₂Cu₃O_7?δ is subjected to detailed heat capacity (C _P ) studies. C _P exhibited well-defined anomaly at below 90 K, which decreases with applied field. Although the C _P anomaly/peak at T _c reduces with applied field, the same is not completely suppressed in high applied fields of up to 12 T. The Sommerfeld constant (γ) and Debye temperature (Θ _D), as determined from low temperature fitting of C _P (T) data to Sommerfeld–Debye model, are 10.65 mJ/mole-K² and 312.3 K, respectively. The results are compared with existing literature on bulk polycrystalline superconducting YBa₂Cu₃O_7?δ sample.