Hard Decision Cooperative Spectrum Sensing Based on Estimating the Noise Uncertainty Factor

Spectrum Sensing (SS) is one of the most challenging issues in Cognitive Radio (CR) systems. Cooperative Spectrum Sensing (CSS) is proposed to enhance the detection reliability of a Primary User (PU) in fading environments. In this paper, we propose a hard decision based CSS algorithm using energy detection with taking into account the noise uncertainty effect. In the proposed algorithm, two dynamic thresholds are toggled based on predicting the current PU activity, which can be successfully expected using a simple successive averaging process with time. Also, their values are evaluated using an estimated value of the noise uncertainty factor. These dynamic thresholds are used to compensate the noise uncertainty effect and increase (decrease) the probability of detection (false alarm), respectively. Theoretical analysis is performed on the proposed algorithm to deduce its enhanced false alarm and detection probabilities compared to the conventional hard decision CSS. Moreover, simulation analysis is used to confirm the theoretical claims and prove the high performance of the proposed scheme compared to the conventional CSS using different fusion rules.Comment: 5 pages, 4 figures, IEEE International Conference on Computer Engineering and Systems (ICCES 2015). arXiv admin note: text overlap with arXiv:1505.0558

Modified capsulorhexis for fluid-filled mature cataracts

Background: The aim of this study was to develop a modified capsulorhexis technique featuring a new maneuver for the removal of subcortical fluid in fluid-filled mature cataracts to avoid high intralenticular pressure. Methods: This prospective interventional study included 33 eyes with mature cataracts and evidence of subcapsular fluid spaces by slit lamp examination.  For each patient, 20% mannitol was administered intravenously according to the bodyweight 1 h preoperatively. Under peribulbar anesthesia, a 2.2-mm main incision was made, and the anterior chamber was filled with a dispersive ophthalmic viscosurgical device. Using a bent-tip cystotome, a 2-mm curved incision was made in the center of the anterior capsule, which released subcortical fluid and was drained through compression of the posterior lip of the main incision using a spatula. Then, fine gentle milking in all quadrants around the puncture on the anterior lens capsule from the periphery toward the site of puncture using the blunt-edged spatula further assists drainage of subcortical fluid and breaks fine septa inside the lens to remove fluid from intralenticular fluid pocket collections. Results: The study included 15 (45.5%) men and 18 (54.5%) women with a mean ± standard deviation (SD) of age of 63.2 ± 5.33 and 64.4 ± 6.21 years, respectively. The modified capsulorhexis technique was performed for 33 intumescent cataracts. Capsulorhexis was completed in all cases; capsulorhexis was easy in 31 (94%) eyes and difficult in 2 (6%) eyes. In the two difficult cases, radial extension occurred in one eye, and it was retrieved using the Little technique; the other case with radial tear was completed successfully using a retinal micro scissor from the other edge of the capsulorhexis until reaching an oval, continuous capsulorhexis. Conclusions: This modified capsulorhexis technique with compression on the posterior lip of the main incision and capsule milking allowed for a safe, continuous curvilinear capsulorhexis. Further comparative studies are necessary to confirm our preliminary results

Structural analysis of metal and semimetal adsorption on Cu{100} by low energy electron diffraction

The structures formed by growing a range of metals and semimetals on Cu{100} single crystal are investigated by quantitative low-energy electron-diffraction (LEED). Symmetrized Automated Tensor LEED (SATLEED) calculations are used to determine the structure of the surface alloys and overlayers formed. The Cu{100}/Pd system has been studied in the Pd coverage range 0.1-1.0 ML using SATLEED and Diffuse LEED (DLEED). Palladium atoms adsorb in the coverage range 0.1 < 0pd < 0.5 ML primarily by substitutional replacement of top layer copper atoms forming a two-dimensional CuxPd].x surface alloys leading to formation of an ordered Cu{100}-c(2x2)-Pd two-dimensional alloy at 0pa = 0.5 ML The kinetics and mechanism of an irreversible overlayer to underlayer transition in the Cu{100}-c(2x2)-Pd surface alloy (0pd = 0.5 ML) has been investigated. The activation energy for Pd site switching from the outermost layer to sub-surface (second layer) sites has been found to be 109±12 kJ mol'1 (1.13+0.12 eV). The structure of the underlayer alloy has been determined by SATLEED. Substitution of 0.5 ML of Pd into subsurface sites leads to significant expansion of the outermost two interlayer spacings Adzi2 = +3.3 ± 3.3 %, Adz23 = +6.6 ± 2.8 %. At monolayer coverage, Pd forms a double layer ordered c(2x2) CuPd alloy with p(2x2)-p2gg symmetry introduced into the outermost layer via clock rotation of the CuPd monolayer with the p(2x2) vertices centred over second layer Pd atoms. Lateral shifts of the top layer Cu and Pd atoms are determined to be 0.25+0.12A. The room temperature deposition of 0.5 ML Pt on Cu{100} followed by annealing to 525 K results an ordered c(2x2) Cu-Pt second layer capped with a pure Cu layer. The first and second interlayer spacings are found to be expanded by +5.1+1.7 % and +3.5+1.7%, respectively (relative to the bulk Cu interlayer spacing of 1.807 A) due to the insertion of the 8% larger Pt atoms into the second layer with Pt atoms rippled outwards towards the solid-vacuum interface by 0.08+0.06 A

Futures and Forwards Contracts from Perspective of Islamic Law

Futures and forwards contracts are considered of the main derivatives contracts, which offer many services and benefits, namely risk management (hedging), and speculation. However, these contracts from the perspective of Islamic experts are varying and non-uniformed, where there are those who see futures and forwards contracts as unacceptable and forbidden by Islamic law, and there are also those who see futures and forward contracts as acceptable and compatible with Islamic law. This paper attempts to clarify the Islamic law perspective of futures and forwards contracts, to give a clearer picture about the legitimacy of these contracts, in order to examine whether the using of futures and forwards contracts are permissible or prohibited. The study follows the inductive method and descriptive research by displaying texts, previous literature, opinions of futures and forwards contracts from Islamic law perspective and comparisons between them, including the balancing and elicitation in light of Islamic law standards, strength of the arguments relied upon by each party and commitment to offer the presentation matter scientifically. The study’s conclusion the current application of futures and forwards contracts in the financial markets are impermissible and are considered prohibited contracts. The study find futures and forwards contracts contain a number of forbidden elements in Islamic law, especially gambling and harm speculation additions to a number of pictures of some forbidden elements such as gharar (ambiguity), riba (usury) that are still in the circle of debate among Muslim scholars. However, the availability of a some terms and conditions that can dispose the prohibited elements in these contracts may make them compatible and consistent with the Islamic law

The Importance of Character Education for Tweens as Consumers

Tweens is a term that denotes a market segment mentality that falls between children at the lower end and teens at the upper end. Tweens marketing strategies are considered critical for most global brands. Advocates against excessive consumerism and materialism polluting innocent childhood, specifically tweens, call for values implantation through character education in the school to breed more educated consumers. The effect of implanting character building programs in schools on the consumer behavior of the exposed children in the marketplace, however, has never been tested before. This research endeavor is, in essence, an overlap between consumer behavior and educational psychology, investigating the link between personality and behavior in the market. It falls under both positivist and interpretive consumer research, specifically the consumer socialization of children. The aim of this work is to develop a conceptual model linking character education to purchasing lifestyles and consumption patterns of the exposed children as consumers. Following, prospects for future research are highlighted.Educational psychology, character education, attitudes and lifestyles, opinion-leadership, humanitarianism, ethnocentrism, adolescents and middle schools

Using Agency Theory in Understanding Switching Behavior in B2B Service Industries “I”

Understanding switching behavior is a cornerstone in sustaining customer led marketing efforts especially in services which depend on long-term relationships with the customers and where the switching process is compound and costly for both the customer and the service provider. The issue of understanding the motives and barriers behind agency-brand switching behavior still needs further conceptual support and empirical investigation in service industries context, where the emphasis placed on investigating the actual switching motives without trying to conceptualize the issue, which if done will result in better understanding for the whole switching process. In this paper, the authors attempt to bridge this gap in the literature by examining the criterion validity of the switching behavior model using the agency theory, as the relation between the business company (principle) and an Advertising agency (the agent) could be described as agency relationship. Furthermore, this approach helps in supporting the efforts for retaining the business-to-business customers, strengthening the relationship with them, developing and adopting globally integrated customer led strategies in different countries, a trend which is expected to dominate the marketing field in the future due to the increasing role of the agency brand selection and switching in today’s world markets.Brand switching, agency theory, business to business marketing, service marketing, international advertising research

Growth Inhibition of Various Pathogenic Microorganisms Using Effective Microorganisms (EM)

In recent years, researchers focus on treatment of wastewater using low-cost treatment processes. Several studies showed that using effective microorganisms (EM) is a promising technology in the treatment of wastewater. However, the treatment mechanism using EM is not clear. In this study, the effect of EM towards several pathogenic microorganisms was investigated to examine its ability to inhibit their growth. The results showed that EM has the ability to inhibit the growth of pathogenic bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Streptococcus faecalis; while no effect was detected on fungi that were examined.&nbsp; &nbsp