Performance assessment of VoIP service over different handover mechanisms in UMTS networks

Many researchers have discussed various topics in universal mobile telecommunication system (UMTS) networks: the process of switching from one cell to another for the subscriber and the impact of the quality of the connection during the transition process, quality of services (QoS), the quality of the uplink and downlink carrier line, the various types of code for the voice transmitted through the Internet, especially the research that discussed voice over internet protocol (VoIP) technology as voice travels from cell to cell in mobile networks, depending on the type of delivery. In this paper, a proposed scenario of a UMTS network was implemented to evaluate the multicellular VoIP movement; the proposed UMTS network was simulated using the OPNET 14.5 simulator. The calculation and analysis of the different parameters of the user while moving from one cell to another with different movement speeds considered, the best mean opinion score (MOS) value (3.19) registered for the scenario (soft handover) comparing with another type of handover (3.00)

Adaptive wavelet thresholding with robust hybrid features for text-independent speaker identification system

The robustness of speaker identification system over additive noise channel is crucial for real-world applications. In speaker identification (SID) systems, the extracted features from each speech frame are an essential factor for building a reliable identification system. For clean environments, the identification system works well; in noisy environments, there is an additive noise, which is affect the system. To eliminate the problem of additive noise and to achieve a high accuracy in speaker identification system a proposed algorithm for feature extraction based on speech enhancement and a combined features is presents. In this paper, a wavelet thresholding pre-processing stage, and feature warping (FW) techniques are used with two combined features named power normalized cepstral coefficients (PNCC) and gammatone frequency cepstral coefficients (GFCC) to improve the identification system robustness against different types of additive noises. Universal Background Model Gaussian Mixture Model (UBM-GMM) is used for features matching between the claim and actual speakers. The results showed performance improvement for the proposed feature extraction algorithm of identification system comparing with conventional features over most types of noises and different SNR ratios

Nd:YAG laser welding of stainless steel 304 for photonics device packaging

Although pulsed Nd:YAG laser welding has been widely used in microelectronics and photonics packaging industry, a full understanding of various phenomena involved is still a matter of trials and speculations. In this research, an ultra compact pulsed Nd:YAG laser with wavelength of 1.064 µm has been used to produce a spot weld on stainless steel 304. The principal objective of this research is to examine the effects of laser welding parameters such as laser beam peak powers, pulse durations, incident angles, focus point positions and number of shots on the weld dimensions: penetration depth and bead width. The ratio of the penetration depth to the bead width is considered as one of the most critical parameters to determine the weld quality. It is found that the penetration depth and bead width increase when the laser beam peak power, pulse duration and number of shot increase. In contrast, the penetration depth decreases when the laser beam defocus position and incident angle increase. This is due to the reduction of the laser beam intensity causing by the widening of the laser spot size. These experimental results provide a reference on an optimal laser welding operations for a reliable photonics device packaging. The results obtained shows that stainless steel 304 is suitable to be used as a base material for photonics device packaging employing Nd:YAG laser welding technique

Degradation of glass polymers due to successive exposure to acid rain and UV radiation

Utilization of polymer products for outdoor applications is continuously increasing. So the stability of polymers against environmental degradation became top of interests for many researchers. The effect of environmental elements on the polymers stability has been studied, but individually. A solution against an environmental element may conflict with a solution against other element. Therefore current study aimed to clarify a sort of these conflicts. Polymethylmethacrylate (PMMA) films as example of glassy polymers are exposed to acid rains and Ultraviolet (UV) radiation in sequenced method for different time intervals. The effects on both structural and optical parameters are deduced from the measurements of Infrared spectra, X-ray diffraction charts, refractive indices and optical dispersion of samples before and after treatments. Chain scission is found to reduce the transparency of the samples. Acid rains are found to enhance the transparency of PMMA films by disordering chain fragments that are released by chain scission. Lot of experimental data are given in many coloured graphs

A FRAMEWORK FOR DEVELOPMENT OF SOCIAL NETWORKING SITE SKILL AMONG RURAL WOMEN COMMUNITIES

Purpose: A Social Networking Site (also social networking service or social media) is a platform to make people connected and share anything about them. The purpose of this research to construct a framework for the Development of Social Networking Site Skill to help women in rural areas to face the growth of ICT. This paper discusses how the proposed framework can help them to develop their skills of marketing using the SNS. This kind of effort, hopefully could empower the targeted marginalized group with the knowledge of information engineering, increase their awareness and utilization of ICT in their everyday actions. Methodology: The data obtained are the result of on-going projects in Setiu Wetlands, Terengganu.  Community rural women in Setiu Wetlands are respondent for this study. A total of 30 people (identified as women entrepreneurs) were respondents and profile data was preliminary studies about the skills and existing ICT literacy and internet use. Main Findings: Based on profiling data that have been collected, a framework for the development of skills in using social media as a business medium has been developed. Implications/Applications: The framework developed is expected to produce successful entrepreneurs from rural women communities. The entrepreneur will be an example to other women. This effort also is expected to help rural women community can improve the living standards of their families

Significant effect of ph on photocatalytic degradation of organic pollutants using semiconductor catalysts

Photocatalytic is one of the inexpensive and non-toxic techniques for degradation of organic pollutants into harmless substances such as water and carbon dioxide. In this study, simple electrolysis method was used in preparation of Ag/TiO2 and α-Fe2O3/HY catalysts. The physicochemical properties of the catalysts were studied using XRD, FTIR, FESEM-EDX and surface area analysis. The pH of solution plays an important role in the photocatalytic degradation of organic pollutants which influences the surface-charge properties of the catalysts. Ag/TiO2 and α-Fe2O3/HY were used as catalyst on degradation of 2-chlorophenol (2-CP) and methyl orange (MO), respectively. The effect of pH on degradation of 2-CP and MO were investigated over a pH range from 2 to 9. Higher degradation of 2-CP and MO were obtained at pH 5 (74%) and pH 2 (80%), respectively. This finding might be explained by the amphoteric performance of the catalyst using point zero charge (pHZPC). The pHZPC for Ag/TiO2 and α-Fe2O3/HY was found to be at pH 6.3 and pH 7.2, respectively. Hence, the activities of the catalysts may have been affected by the existence of a strong electrostatic field between the positively charged catalysts surface and negatively charged 2-CP and MO caused a pH value lower than their pHZPC give greater degradation

Analysis of temperature sensor in all-pass microring resonator

The temperature sensor using all-pass microrin resonator (APMRR) investigated theoretically and analyzed. An optical bright soliton is used as a probe to study the effect of applied temperature on the light behavior pass through microring waveguide. The split-step Fourier method is used to study the pulse propagation inside the APMRR. Result shows that the rise of temperature on peak amplitude ratio fit with quadratic line in temperature range of 27 oC-37 oC. . The temperature at 30 oC generate higher slope of reduction compare to temperature at 36oC. The amplitude ratio is reduced into 0.6 (-4.4370 dB) when the temperature increased as small as 1 oC. The operating range for all-pass resonator is 97 oC with amplitude reduction of -8.3975 dB

Photonic and or gate by using fiber coupler

The development of optical logic gate by using fiber coupler can be realized by properly determine the delay in Pulse Position Propagation (PPM) to set a logic bit in Time Domain Multiplexing (TDM) systems. Soliton has been used to maintain the pulse shape for a long haul distance connection up to 100km. In this study, a numerical modeling of secant hyperbolic soliton pulse based on Nonlinear Schrodinger Equation (NLSE) was performed in balance of Self-Phase modulation and Group velocity dispersion by normalized distance, time and field calculated by 1032 iteration step. Two picosecond soliton pulse transmission in anomalous dispersion region served as input generated inside fiber coupler and the code generator will encode signal within the altered time difference of ±0.25t. The signal would move in the fiber coupler and the phase modulator controls the phase of the bisoliton generation from 0 to 2p. The result is the formation of optical logic AND and OR gate at the phase difference of 0.4p and 1.1p with normalized power of ~6 and parameter offset ε=0.25

Numerical and Experimental Study of CPU Cooling with Finned Heat Sink and Different P.C. Air Passages Configurations

This study investigated numerically and experimentally fluid flow and heat transfer in the desktop PC. Three patterns of the positions of air inlet and outlet were tested to find the best one for cooling. The computer components in the present study are CPU, finned heat sink, power supply, motherboard, CD, HDD and fans. Three components which were generate heat are CPU, motherboard and power supply and there were two openings for air inlet and two for air outlet. The air inlet velocities were 1.2, 1.8, 2.4 m/s with constant CPU fan velocity. The studied parameters were the changed of inlet air velocity, powers of CPU, motherboard and PSU and the positions of inlet air. The numerical results obtained are found in a good agreement with the experimental results. The experimental results show that the maximum temperature was 81  at 16.5 W and 1.2 m/s. Numerical results showed that the CPU temperature reaches 89.6  at 18.5 W and 1.2 m/s. From the results, it was found that; the temperatures of the main components (PSU and motherboard) affected little by CPU power and vice versa, the finned heat sink has higher cooling efficiency and the pattern 1 was the best pattern for CPU cooling