Fast Decodable Turbo Codes

Decoding delay is an important consideration for the use of turbo codes in practical applications. We propose a new structure for turbo codes which is very suitable for parallel decoding. It is shown by union bound analysis and simulation results that the proposed system performance is comparable to that of the classical turbo codes     

Concomitant Crystallization of Copper(II) Sachharinato Complexes with 2-methylpyrazine as a Monomer and an One-dimensional Polymer: Syntheses,Crystal Structures,Spectroscopic and Thermal Properties

The reaction of [Cu(sac)₂(H₂O)₄] · 2H₂O with 2-methylpyrazine (mpyz) leads two complexes, concomitant crystallization of a mononuclear complex [Cu(sac)₂(mpyz)(H₂O)₂] (1) and a polymeric complex [Cu(sac)₂(μ-mpyz)]_n (2). Both complexes have been characterized by elemental analyses, magnetic measurements, FT-IR and ESR, TG-DTA and single-crystal X-ray diffraction analyses. Single-crystal X-ray analyses show that complex 1 consists of discrete molecules in which the copper(II) ions exhibits a square-pyramidal coordination geometry. The individual molecules of 1 are connected into a hydrogen-bonded chain structure, which is further assembled to form a three-dimensional network by π–π stacking interactions. Complex 2 is an 1D coordination polymer in which copper(II) centers are bridged by the mpyz ligand. The chains are further assembled to form two-dimensional frameworks by π–π and C–H···π stacking interactions.     

纳米RDX基PBX混合炸药的热分解特性和感度研究?

采用溶液-水悬浮法,通过控制料液质量比、包覆温度、搅拌速度等工艺参数制备了纳米RDX基PBX。使用TG/DSC同步热分析仪研究其热分解特性,并依据GJB 772A—1997分别对其撞击感度和摩擦感度进行了测试。结果表明:与微米RDX基PBX相比,纳米RDX基PBX的DTG峰温提前约0.6℃,活化能降低约2.5 k J/mol;纳米RDX基PBX撞击感度H_(50)为46.3 cm,微米RDX基PBX H_(50)为29.8 cm,相对降低55.4%;纳米RDX基PBX摩擦感度比微米RDX基PBX相对降低21.1%。     

Comparison on efficiency factors of F and C types of fly ashes

Fly ashes are obtained from thermal power plants and they are pozzolanic materials, which can act as partial replacement material for both portland cement and fine aggregate. With their economical advantages and potential for improving fresh and hardened concrete performance, they have some benefits for using in concrete industry. In this study, the objective was to find the efficiency factors of Turkish C and F-type fly ashes and to compare their properties. Three different cement dosages were used (260, 320, 400 kg/m³), two different ratios (10% and 17%) of cement reduced from the control concretes and three different ratios (depending on cement reduction ratio) of fly ash were added into the mixtures. At the ages of 28 and 90 days, compressive strength, modulus of elasticity and ultrasound velocity tests were carried out. From the compressive strength results, the k efficiency factors of C and F-type fly ashes were obtained. As a result, it is seen that efficiency factors of the concrete produced by the replacement of F and C type fly ashes with cement increase with the increase in cement dosage and concrete age.     

NODIC: a novel distributed clustering routing protocol in WSNs by using a time-sharing approach for CH election

Wireless Networks - Due to the battery limitations, energy-efficient routing is one of the most important issues in WSNs. In this paper, a novel distributed clustering routing protocol (NODIC) is...     

Stability analysis of social foraging swarms.

In this article we specify an M-member "individual-based" continuous time swarm model with individuals that move in an n-dimensional space according to an attractant/repellent or a nutrient profile. The motion of each individual is determined by three factors: i) attraction to the other individuals on long distances; ii) repulsion from the other individuals on short distances; and iii) attraction to the more favorable regions (or repulsion from the unfavorable regions) of the attractant/repellent profile. The emergent behavior of the swarm motion is the result of a balance between inter-individual interactions and the simultaneous interactions of the swarm members with their environment. We study the stability properties of the collective behavior of the swarm for different profiles and provide conditions for collective convergence to more favorable regions of the profile.     

Virtue ethics, multiculturalism, and the paradox of cultural dialogue.

Comments on the article by Fowers and Davidov, "The virtue of multiculturalism: Personal transformation, character and openess to the other," (see record 2006-11202-002). Fowers and Davidov offered a virtue-based approach to understanding and fostering multiculturalism in psychology. Fowers and Davidov argued that multiculturalism fulfills the classical components of being a virtue, being a worthy goal that requires the wise use of consistent and worthwhile goods. They concluded that the virtue of multiculturalism and its correlate, openness, provide a sound basis for transformative cultural dialogue. It appears that Fowers and Davidov may be caught in what Meiland (1980) has called "The Paradox of Cognitive Relativism." I would argue that the problem, rather than being a faulty argument on their part, is the intrinsic incoherence of an ethic of multiculturalism, which insists that we respect a diversity of cultural backgrounds, and yet insists. The virtue model of ethics is relevant to our cultural concerns as psychologists but certainly does not resolve them. Instead, because it is soundly based in the idea of personal character, its value lies in bringing to light the very dilemmas involving human similarity and difference that have troubled psychologists since the inception of the field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heat transfer enhancement in a tube using circular cross sectional rings separated from wall

A numerical study was undertaken for investigating the heat transfer enhancement in a tube with the circular cross sectional rings. The rings were inserted near the tube wall. Five different spacings between the rings were considered as p = d/2, p = d, p = 3d/2, p = 2d and p = 3d. Uniform heat flux was applied to the external surface of the tube and air was selected as working fluid. Numerical calculations were performed with FLUENT 6.1.22 code, in the range of Reynolds number 4475–43725. The results obtained from a smooth tube were compared with those from the studies in literature in order to validate the numerical method. Consequently, the variation of Nusselt number, friction factor and overall enhancement ratios for the tube with rings were presented and the best overall enhancement of 18% was achieved for Re = 15,600 for which the spacing between the rings is 3d.     

The Effect of NaCl on the Krafft Temperature and Related Behavior of Cetyltrimethylammonium Bromide in Aqueous Solution

This paper presents the effect of NaCl on the Krafft temperature (T _K), surface adsorption and bulk micellization of cetyltrimethylammonium bromide (CTAB) in aqueous solution. The critical micelle concentration (CMC) of CTAB in the presence of NaCl increased and then decreased with increasing temperature. Thus, the CMC–temperature data can be represented by a bell-shaped curve. The micellar dissociation (fraction of counterion binding) and energetic parameters (free energy, enthalpy and entropy changes) of both adsorption and micellization were calculated. The processes were found to be both enthalpy and entropy controlled and appeared to be more and more enthalpy driven with increasing temperature. An enthalpy–entropy compensation rule was observed for both adsorption and micelle formation. The T _K of the surfactant decreased significantly in the presence of NaCl, which is a sharp contrast to the usual behavior of the effect of electrolytes on the T _K of classical ionic surfactants. The surface excess concentrations decreased with increasing temperature. However, the values were much higher in the presence of NaCl compared to the corresponding values in pure water. The solubilization behavior of a water-insoluble dye, Sudan red B (SRB), in the micellar system was studied by the UV–visible spectrophotometric technique. The molar solubilization ratio in the presence of NaCl was found to be about three times higher than that in pure water, indicating that the solubilization of SRB in the CTAB micelles significantly increases in the presence of NaCl.