Papers by Keyword: DMS

Abstract: Undoped ZnO, Gd-doped ZnO, and (Al, Gd) co-doped ZnO thin films were synthesized using the co-sputtering technique on a glass substrate. XRD data confirmed all the films are hexagonal structures with dominant (002) diffraction peaks. There are no secondary phases or other peaks detected except for ZnO which proves well incorporation of Gd³⁺ and Al³⁺ ions into ZnO ions for Gd and (Al, Gd) co-doping ZnO thin films. The EDX analysis shows the composition of Al, Gd, Zn, and O for (Al, Gd) co-doped ZnO thin films considering the successfully doping of Gd and Al into ZnO structure by this deposition method. As compared with undoped ZnO and Gd-doped ZnO, the electrical properties of (Al, Gd) co-doped ZnO showing a good enhancement of carrier concentration (2.34 x 10²⁶ m^-3) and electrical conductivity (1.41 x 10⁵ Ωm^-1) whereas the resistivity is low about 7.11 x 10⁴ Ωcm.

Abstract: Multi-channel dynamic matrix sound system (DMS) is a multi-channel input and output sound system which is based on source synthesis and Huygens' principle. The sound sources are recorded by microphone array and multi-channel independent recording, instead of the field. This paper describes the results of the subjective evaluation experiments between DMS and conventional stereo system by the semantic differential (SD) method. Five parts of the audio materials and a training material, including the human voice, music, sound effects, were used as the stimuli. All of the stimuli were recorded by the DMS and conventional stereo system respectively. The results proof that the effectiveness of DMS, which has a higher level of sound quality and can give the audience the experience of dynamic subjective feelings compared with conventional stereo system. Furthermore, sound designers must carefully consider the influence of gender, age, preferences on the hearing impression.

Abstract: By studying static scheduling algorithm Deadline Monotonous Scheduling (DMS) which assigns the priority fixedly to each message based on its deadline before starting the system and dynamic scheduling algorithm Earliest Deadline First (EDF) which assigns the priority dynamically based on its remaining deadline in the running time of system, combining the cheap CPU cost of DMS and high network utilization of EDF and using the layered structure, we presented a hybrid scheduling algorithm with considering critical level of messages. Based on the work mentioned above, the simulation platform of CANbus is developed with MATLAB/SimEvents tool box. The platform was used to real-time analysis for the scheduling algorithms mentioned before, the simulation results showed that the hybrid scheduling algorithm could not only improve the real-time performance of system, but also reduce the cost of processor.

Abstract: In this paper we have obtained CdCrTe thin layers by PLD method using the YAG:Nd3+ laser with pulse length 250μs. Synthesized CdCrTe solid solution with 50% at. of Cr has been taken as a target. The layers were deposited on KCl substrate. The target and films were analyzed using X-ray diffraction, TEM microscope and THEED electron diffraction. The morphology of the layers are homogenous. However, we have detected several crystallographic phases: cubic CdTe, hexagonal Cr and hexagonal Te. From the measurements of lattice constant of the layer, their composition was determined to be x=0,14

Abstract: Nanocrystalline Fe-doped TiO₂ was prepared by Sol-Gel technique, which was followed by freeze at-30°C temperature for 12hrs. The obtained Gel was thermally treated at 200,400,600 and 800°C. X-ray Powder Diffraction (XRD), Scanning Electron microscopy (SEM), UV-Vis Spectroscopy, Photo luminescence (PL) and EDAX was used to study its Structural and Optical properties. All Fe-doped TiO₂ nanostructures show an appearance of Red shift relative to the bulk TiO₂. The XRD pattern show the coexistence of major anatase phase and minor brookite phase for samples treated up to 600°C. Whereas at 800°C rutile is the only phase observed. All Fe doped TiO₂ nanostructures show an appearance of Red shift relative to bulk undoped TiO₂. The magnetic property by Gouy Balance of Fe doped TiO₂ exhibit Peramagnetism at room temperature.

Abstract: ZnO is a semiconductor that can be doped with transition metal ions, and thus becomes feasible to use in the diluted magnetic semiconductor (DMS), or semiconductor with magnetic properties. In this work we have studied the influence of doping of Ni⁺² on the structural, morphological and magnetic properties of Zn_1-xNi_xO system, to x = 0.07, 0.1 and 0.2 mol of Ni⁺² synthesized by combustion reaction. The systems were characterized by XRD, SEM and VSM. The maximum temperatures ranged from 639 K and 683 K. All systems showed a majority phase formation of ZnO, with the presence of the second phase NiO. The crystallite size for the majority phase varied between 49 and 56nm. All systems have resulted in samples with a morphology consisting of dense clusters, formed by particles pre-sintered and shaped roughly hexagonal plates. The magnetic measurements showed that the values of saturation magnetization lies between 4.6 to 28.5emu/g, remanent magnetization of 0.01 to 0.3 emu/g, coercive force values varies between 12.7 and 62.4 Oe and Curie temperature ranging from 308 to 311K.

Abstract: In this article, Co-doped SrTiO₃ nanofibres have been prepared by electrospinning from a sol-gel precursor and the following calcination at 923K. XRD results confirmed that no second phase was formed, and Co ions successfully occupied the Ti sites. By annealing in hydrogen, oxygen vacancies and (Co-H-Co) were formed, which both contributed to the magnetic ordering in SrTi_1-xCo_xO₃ nanofibres are at 300K.

Abstract: Using general graduated approximation (GGA) of the ab-initio based on density functional theory (DFT), three models of possible double Fe doping GaN and three models of possible N vacancy and double Fe codoping GaN were calculated. The results show that in the three models of double Fe doping GaN, the energies of antiferromagnetism (AFM) are lower than the ones of ferromagnetism (FM), which shows that the ground state of Fe doping GaN will be AFM, this agrees on the conclusion of literature [15]. After adding vacancies 2 and 3 respectively, we found a ferrimagnetic (FIM) ground state. But after adding vacancy 1, the ground state was still AFM.

Abstract: Researches on Destination Marketing System (DMS) now still have problems addressed both in the fundamental theory and operation practice. This paper paid much attention to the operation and evaluation of DMS, in which Tourist Destination Image was introduced to help design a new evaluation module added to the system. In this module, tourist responded to a survey on tourist destination image to be a reference for evaluation. Besides, supplementary means were also designed to make it reasonable for tourists. In this way, solutions for evaluation and adjusting destination promotion through DMS are raised for enterprises and policy makers.

Abstract: Diluted magnetic semiconductors (DMS), which have both semiconducting and magnetic properties, are those in which transitions metal ions substitute cations of host semiconductor materials [1]. There is a great interest for DMS for use as the material of spintronics. In this study is reported the structural and morphologic characterization of Zn1.95Co0.05O nanoparticles obtained by Pechini method and combustion reaction. The powders resulting were characterized by X-ray diffraction (XRD) for determination of the phases, crystalline phase and lattice parameter; nitrogen adsorption by BET for determination of the specific superficial area and calculation the particle size from the superficial area and scanning electron microscopy (SEM) for morphologic analysis. The XRD results demonstrated the viability of obtaining crystalline and nanosize powders by the both synthesis routes. For all samples the average crystallite sizes was nanosized, but the powders obtained by reaction combustion is smaller. The SEM micrographs shows that the powders obtained for both syntheses are constituted of soft agglomerates.