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Gas adsorption and Surface Diffusion on 5Ã… Microporous Adsorbent in Transition and Turbulent Flow Region
No full textThe flow of O2, H2 and CO2 was in transition regime at relatively lower ΔT and then became turbulent at relatively higher ΔT when passed through the 5Å microporous zeolite adsorbent. Adsorption and surface diffusivity of all the gases that are being studied in these regimes increased with increase in ΔT. For the temperature difference from 5 to 115 K, the range of adsorption of O2 was between 6.319?10-12 and 5.762?10-11 kg/s. The adsorption of H2 was between 4.4?10-13 and 3.88?10-12 kg/s for the temperature difference ranging from 1 to 20 K. The adsorption of CO2 was between 5.3?10-12 and 4.9?10-11 kg/s for the temperature difference ranging from 5 to 100 K. At pressure of 1 bar, CO2 adsorption was the highest at all ΔT, followed by O2 and H2. The surface diffusivity increases with increase in ΔT. At a particular ΔT, the diffusivity increases asymptotically regardless of the flow regions
Operational characteristics optimization of human-computer system
No full textComputer operational parameters are having vital influence on the operators efficiency from readability viewpoint. Four parameters namely font, text/background color, viewing angle and viewing distance are analyzed. The text reading task, in the form of English text, was presented on the computer screen to the participating subjects and their performance, measured in terms of number of words read per minute (NWRPM), was recorded. For the purpose of optimization, the Taguchi method is used to find the optimal parameters to maximize operators’ efficiency for performing readability task. Two levels of each parameter have been considered in this study. An orthogonal array, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to investigate the operators’ performance/efficiency. Results showed that Times Roman font, black text on white background, 40 degree viewing angle and 60 cm viewing distance, the subjects were quite comfortable, efficient and read maximum number of words per minute. Text/background color was dominant parameter with a percentage contribution of 76.18% towards the laid down objective followed by font type at 18.17%, viewing distance 7.04% and viewing angle 0.58%. Experimental results are provided to confirm the effectiveness of this approach
ON PERFORMANCE ANALYSIS OF AMBR PROTOCOL IN MOBILE AD HOC NETWORKS
Get PDFDue to mobility of nodes in ad hoc networks, the most challenging issue is to design and to make sound analysis of a routing protocol that determines its robustness to deliver packets in low routing packet overhead. In this paper, we thoroughly analyzed the Adaptive Monitor Based Routing (AMBR) protocol by varying different parameters that affect a routing protocol to measure its performance. Analysis shows that it requires less routing control overhead comparing with other prevalent routing protocols. An improved analytical model is also presented in this paper. All these analyses firmly prove that AMBR is a sound and robust protocol in terms of flooding, routing overhead and hence, enhances reliabilit
MULTI-LEVEL SAMPLING APPROACH FOR CONTINOUS LOSS DETECTION USING ITERATIVE WINDOW AND STATISTICAL MODEL
Get PDFThis paper proposes a Multi-Level Sampling (MLS) approach for continuous Loss of Self-Similarity (LoSS) detection using iterative window. The method defines LoSS based on Second Order Self-Similarity (SOSS) statistical model. The Optimization Method (OM) is used to estimate self-similarity parameter since it is fast and more accurate in comparison with other estimation methods known in the literature. Probability of LoSS detection is introduced to measure continuous LoSS detection performance. The proposed method has been tested with real Internet traffic simulation dataset. The results demonstrate that normal traces have probability of LoSS detection below the threshold at all sampling levels. Meanwhile, false positive detection can occur where abnormal traces have probability of LoSS that imitates normal behavior at sampling levels below 100ms. However, the LoSS probability exceeds the threshold at sampling levels larger than 100ms. Our results show the possibility of detecting anomaly traffic behavior based on obtaining continuous LoSS detection monitorin
IMPROVING NONLINEAR PROCESS MODELING USING MULTIPLE NEURAL NETWORK COMBINATION THROUGH BAYESIAN MODEL AVERAGING (BMA)
Get PDFImproving model generalization of aggregated multiple neural networks for nonlinear dynamic process modeling using Bayesian Model Averaging (BMA) is proposed in this paper. Using BMA method, the posterior probability of a particular network being the true model is used as the combination weight for aggregating the network despite of using fixed combination weight as the model. The posterior probabilities are calculated using the sum square error (SSE) from the training data on each of the sample time, and tested to the testing data. The selections for the final weight are based on the least SSE calculated when each of the posterior probability is applied to the testing data. The likelihood method is employed for calculating the network error for each input data. Then, it is used to calculate the combination weight for the networks. Two non-linear dynamic system-modeling case studies are selected for this proposed method, which are water tank level prediction and pH neutralization process. Application result demonstrates that the combination using BMA technique can significantly improve model generalization compared to other linear combination approaches
TUNABLE BANDPASS FILTER USING RF MEMS SWITCHES
No full textoai:ojs2.journals.iium.edu.my:article/6A band pass tunable RF filter is proposed by using Radio Frequency (RF) Microelectro Mechanical Systems (MEMS). The tunability is obtained by using capacitive MEMS switches that can be tuned within the bandwidth of 3.6 GHz to 4.4 GHz. The performance of the filter depends on geometry and location and types of the MEMS switches. Optimization has been done to achieve tunability by using 3-D high frequency electromagnetic simulator (HFSS)
DESIGN AND PERFORMANCE ANALYSIS OF VCO FOR STANDARD GSM USING MEMS
Get PDFThe design of a prototype monolithic Micro Electro-Mechanical Systems (MEMS) electronic circuits, namely the Voltage Controlled Oscillators (VCOs) is presented. The components can achieve the stringent requirements of wireless communication applications such as GSM cellular telephony. The VCO meets the low phase noise specifications of -136 dBc/Hz at large offset frequency of 3MHz, over the appropriate frequency range. The model of the monolithic VCO is based on the topology of the Colpitts Oscillator. It is relatively less complicated, which facilitates the practical integration of the MEMS components into the configuration. The variable capacitor and the monolithic 3-D coil inductor are suitable for low phase-noise and low power consumption at the application frequencies. A PSpice simulation model was developed with MEMS switching devices that can be integrated into the system. The model helps in determining the design parameters, which affect the performance and operation reliability of the RF transceiver system, for which a prototype has been tested and proved successful
FAST ZEROX ALGORITHM FOR ROUTING IN OPTICAL MULTISTAGE INTERCONNECTION NETWORKS
Get PDFBased on the ZeroX algorithm, a fast and efficient crosstalk-free time- domain algorithm called the Fast ZeroX or shortly FastZ_X algorithm is proposed for solving optical crosstalk problem in optical Omega multistage interconnection networks. A new pre-routing technique called the inverse Conflict Matrix (iCM) is also introduced to map all possible conflicts identified between each node in the network as another representation of the standard conflict matrix commonly used in previous Zero-based algorithms. It is shown that using the new iCM, the original ZeroX algorithm is simplified, thus improved the algorithm by reducing the time to complete routing process. Through simulation modeling, the new approach yields the best performance in terms of minimal routing time in comparison to the original ZeroX algorithm as well as previous algorithms tested for comparison in this paper
Catalytic Combustion of Voc in Air Stream Over Bimetallic Chromium-Copper Supported On Sicl4-Modified H-Zsm-5 Catalyst
No full textThe performance of chromium (Cr) and copper (Cu) on silicon tetrachloride modified H-ZSM-5 (SiCl4-Z) catalyst in VOC combustion is reported. H-ZSM-5, modified with SiCl4 at 500?C for 3 h was impregnated with 1.0 wt. % of Cr and 0.5 wt. % of Cu. Performance studies were carried out at GHSV of 3,800 to 32,000 h-1 with 2,000 to 35,000 ppm of VOC. Changes in the activity of Cr-Cu/ SiCl4-Z were ascribed to extra framework deposits, surface acidity and pore characteristics. Cr-Cu/SiCl4-Z catalyst was more stable to coking, humidity and HCl than Cr-Cu/Z. In the combustion of chlorinated VOC, the chlorination of metal species deactivated the catalyst by rendering lower redox ability
An Efficient Tasks Scheduling Algorithm for Distributed Memory Machines With Communication Delays
No full textThe scheduling of multiple interacting tasks of a single parallel program is considered the most important issue to exploit the true performance of the multiprocessor system. The problem is to find a schedule that will minimize the execution time (Make_Span) of a program. On the other hand, task scheduling on a multiprocessor system with and without communication delays is known to be NP-complete problem. Consequently, many heuristic algorithms have been developed, each of which may find optimal scheduling under different circumstances. One of the well known iterative algorithms is the hill-climbing. This algorithm starts with a complete solution and searches to improve this solution by choosing a better neighbor based on a cost function. This will lead to a local optimum which is considered the main drawback of this algorithm. The research in this study concerns to develop an efficient iterative algorithm for scheduling problem based on the hill-climbing. Present algorithm satisfies a local optimum that is very close to the global one in a reasonable amount of time. In most experiments, it satisfies the actual global optimum