A HGGSA Approach to Beam Forming for DOA Estimation in Smart Antenna Arrays

Beam forming is one of the most important processes in smart antenna systems for DOA estimation. The most important function in beam forming is changing beam pattern of antenna for a particular angle. If the antenna does not change the position for the specified angle, the signal losses will be high. For avoiding this, a hybrid method, called HGGSA (hybrid genetic and gravity search algorithm) is proposed that is developed by combining genetic algorithm and GSA to beam forming for DOA estimation in smart antenna arrays. In the proposed method, if an angle is given as input, it will give the maximum signal gain in the beam pattern of the antenna with corresponding position and phase angle after searching through the space based on the HGGSA algorithm.

     

Recommender system: prediction/diagnosis of breast cancer using hybrid machine learning algorithm

Multimedia Tools and Applications - Breast cancer is the second popular cause of the women’s death. There are some existing techniques for identifying the breast cancer and one of them is...     

Salient object based visual sentiment analysis by combining deep features and handcrafted features

Multimedia Tools and Applications - With the rapid growth of social networks, the visual sentiment analysis has quickly emerged for opinion mining. Recent study reveals that the sentiments conveyed...     

An extractive text summarization approach using tagged-LDA based topic modeling

Multimedia Tools and Applications - Automatic text summarization is an exertion of contriving the abridged form of a text document covering salient knowledge. Numerous statistical, linguistic,...     

Fabrication of superhydrophobic and self cleaning PVA-silica fiber coating on 304L SS surfaces by electrospinning

In this work superhydrophobic coating with self cleaning property is fabricated on 304L SS samples directly using a simple one step electrospinning process followed by silane treatment by using polyvinyl alcohol (PVA) and tetraethyl orthosilicate solution. A maximum water contact angle of 169.2° ± 2.1° is obtained at an electrospinning potential of 15 kV for 2 h, with a distance of 18 cm between the collector and needle. The hierarchical nanostructures thus formed on 304L SS composed of poly(vinyl alcohol)-silica microbeads and nanofibers. The surface morphologies are optimized by varying the electrospinning voltage, time, distance between needle and the collector and aging duration of the precursors. Attenuated total reflectance-infrared spectroscopy studies at different stages of preparation confirmed the presence of PVA/SiO₂ composite nanofibers deposited on the 304L SS surface. The reaction of SiO₂ nanofibers with hexamethyl disilazane resulted in the formation of Si O Si bonds that provided water repellent property. The developed SHP surface coating on 304L SS sample showed dynamic bouncing of water droplets and excellent self cleaning performance. The sample retained the SHP behavior in chloride solutions with different ionic strengths and pH.     

Rietveld refinement,micro-structural,optical and thermal parameters of zirconium titanate composites

Pure titania and zirconium titanate composites have been synthesized using sol-gel technique and annealed at 650, 875 and 1100 °C for 4 h. Acetylacetone was used to control the rate of hydrolysis of precursors. The Rietveld refinement, micro-structural, optical and thermal parameters of prepared composites was investigated. Effect of annealing and concentration of Zr and Ti in composites on their crystal structure, morphology, PL emission wavelength and band gap have been studied. X-ray diffraction and Rietveld analysis exhibit that all prepared samples of composites have orthorhombic single phase of zirconium titanate with space group pbcn. The lower values of profile parameters such as R_p, R_wp, R_B, R_F, χ² indicated that the calculated diffraction pattern is in fair agreement with observed pattern. The increase in zirconia concentration decreases the degree of crystallization of ZrTiO₄. The photoluminescence spectra show the blue shifting of emission peak at 420 nm as the zirconia concentration increases. The optical band gap of zirconium titanate composites also blue shifted (3.24–3.64 eV) with decrease in crystallite size of composites.     

Cost analysis in two-unit warm standby models with a regular repairman and patience time

The present paper deals with two-unit warm standby models having one regular and one expert repairman. It is assumed that the expert is called only if the regular repairman is not able to complete the repairs within some tolerable (patience) time. In model 1, it is assumed that the regular repairman can always do the repairs of the unit, failed from standby state. In model 2, the regular repairman sometimes may not be able to do the repairs of the above nature within some patience time and the expert is called for in case of standby failure also.The various measures of system effectiveness are calculated using semi-Markov and regenerative processes. Based on these measures a rule is developed when the services of the expert man should be utilized profitably.     

Infinite arrays and controlled deterministic table 0L array systems

Deterministic table 0L array systems with control are considered for the generation of infinite arrays. Rewriting of a rectangular array is done in parallel by a table of rules, the rightmost edge horizontally or the lowermost edge vertically downwards. The application of the tables is controlled by a control set. Cube-free and square-free infinite arrays are obtained as an application of this model. The adherence of the array language of a controlled deterministic table 0L array system is related to the adherence of its control set. The limit language equivalence problem and the adherence equivalence problem are shown to be undecidable for this system.     

Effects of wavelength and intensity of light in initiation of body fattening and gonadal growth in a migratory bunting under complete and skeleton photoperiods

A series of experiments investigated the effects of wavelength and intensity of light in initiation of body fattening (gain in body weight) and gonadal growth in migratory blackheaded bunting under complete and skeleton photoperiods. Using fluorescent light at an intensity approximately 700 lx, the first experiment compared the inductiveness of a complete (13 h continuous light coupled with 11 h darkness; 13L:11D) and a skeleton (two light pulses of 6 and 1 h at 6 h apart; 6L:6D:1L:11D) photoperiod. Observations at the beginning and after 3, 8, 10, and 13 weeks of the treatment indicated that both photoperiods were fully inductive but that birds under 13L photoperiod fattened and lost body weight significantly earlier than birds under skeleton photoperiod. In the second experiment, bunting were subjected to 13L:11D (L = 100 lx; D = 0 lx) of white, green (528 nm), and red (654 nm) light for a period of 5 weeks. Birds gained weight and testes grew in all groups except for an inconsistent fattening response in the white light group. The third experiment tested if the inductive effects of 1-h light pulse in a skeleton photoperiod were intensity dependent. Groups of bunting were exposed to 6L:6D:1L:11D (intensity of 1-h white light pulse = 2, 10, 50, or 100 lux) and examined at the beginning and after 3 and 8 weeks of the treatment. Photoinduction occurred at a slower rate and only at 50- and 100-lx intensities. The fourth experiment was similar to the third in design but it employed 1-h light pulse of two different wavelengths (green = 528 nm, and red = 654 nm) at 50- and 100-lx intensities. Birds fattened and testes grew only under red light. The last experiment varied the wavelength and intensity of the first (6 h) light pulse of the skeleton photoperiod (6L:6D:1L:11D): 6-h entraining light pulse of white, green (528 nm), or red (654 nm) colour at 10- or 50-lx intensity was used with 1-h inducing light pulse of white light at approximately 700-lx intensity. Testes grew in all groups but significant fattening occurred only in birds entrained to 50-lx light intensity. These results indicate i) the dissociation of body weight and gonadal responses, in the sense that the timing of photostimulation and/or magnitude of photoperiod-induced body weight and testicular responses differed under various photoperiodic manipulations, and ii) the circadian processes involved in photoperiod-induced responses have differential spectral and intensity sensitivity.