Generalized Cochannel Outage Analysis with DTX in PCS Channels

Spectrum limitations are often a deterrent for swift growth of cellular radio systems. Therefore, different technologies have been explored to enhance the Radio Frequency (RF) capacity as well as to improve the communication quality. Recent technologies suggest the use of Discontinuous Transmission (DTX) as a mean to achieve these goals. In this paper, we analyze and quantify the performance improvement which result from implementing DTX in microcellular systems. The performance criteria is chosen to be the outage probability of de signal to interference ratio. Closed form expressions are derived for outage probabilities for systems using discontinuous transmission. Results are obtained for generalized Nakagami(n)/Nakagami(m) channels as well as for Ricean/Nakagami(m) environments. Moreover, since DTX effectiveness depend on voice patterns, modified expressions are developed for average outage probabilities which take into consideration different voice activity factors.     

Predicting lateral displacement caused by seismic liquefaction and performing parametric sensitivity analysis: Considering cumulative absolute velocity and fine content

Lateral displacement due to liquefaction (D_H) is the most destructive effect of earthquakes in saturated loose or semi-loose sandy soil. Among all earthquake parameters, the standardized cumulative absolute velocity (CAV₅) exhibits the largest correlation with increasing pore water pressure and liquefaction. Furthermore, the complex effect of fine content (FC) at different values has been studied and demonstrated. Nevertheless, these two contexts have not been entered into empirical and semi-empirical models to predict D_H. This study bridges this gap by adding CAV₅ to the data set and developing two artificial neural network (ANN) models. The first model is based on the entire range of the parameters, whereas the second model is based on the samples with FC values that are less than the 28% critical value. The results demonstrate the higher accuracy of the second model that is developed even with less data. Additionally, according to the uncertainties in the geotechnical and earthquake parameters, sensitivity analysis was performed via Monte Carlo simulation (MCS) using the second developed ANN model that exhibited higher accuracy. The results demonstrated the significant influence of the uncertainties of earthquake parameters on predicting D_H.     

Swarm intelligence based robust active queue management design for congestion control in TCP network

Active queue management (AQM) is an effective solution for the congestion control problem. It can achieve high quality of service (QoS) by reducing the packet dropping probability and network utilization. Three robust control algorithms are proposed in this paper in order to design robust AQM schemes: conventional controller, robust particle swarm optimization (PSO)‐based PID (proportional–integral–derivative) (PSOPID) controller, and robust ant‐colony optimization (ACO)‐based PID (ACOPID) controller. PSO and ACO methods are used to tune the PID controller parameters subject to constraints to achieve the required robustness of the network. Robust PSOPID and ACOPID controllers can achieve desirable time‐response specifications with a simple design procedure and low‐order controller in comparison to the conventional controller. Wide ranges of system parameters change are used to show the robustness of the designed controllers. The ability of the designed controllers to meet the specified performance is demonstrated using MATLAB 7. 11, (R2010b): The MathWorks, Inc.3 Apple Hill Drive Natick, MA USA. On the other hand, to verify the effectiveness of the designed controller, nonlinear simulation is performed using the NS2 package. Finally, it is shown by comparison that the proposed robust ACOPID can achieve more desirable performance than the PSOPID controller and the controllers that have been proposed in previous works. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Adaptive color image watermarking based on a modified improved pixel-wise masking technique

In this paper, a family of modified wavelet-based watermarking techniques is proposed. This family of techniques is based on the improved pixel-wise (PW) watermarking scheme. The basic proposed algorithm considerably improves the PSNR of the watermarked image (in the range of 2.20–7.28 dB), and is based on selecting specific locations in the three detailed sub-bands of the first level of the DWT decomposition of the image. The selective nature of the modified PW method (denoted as selective PW: SPW) allows the scheme to be adaptive in terms of the imperceptibility and the watermark size. Also, the PW and SPW methods were extended to be implemented with color images: (1) grayscale-wise PW method (G-PW) that embeds the watermark in the Y component of the YCbCr model. (2) Multi spectral-PW method (MS-PW) that embeds the watermark in the R, G, and B layers independently. (3) Multi spectral-SPW method (MS-SPW) that gains high PSNR value compared with MS-SPW, and (4) multi spectral-maximum PW method (MS-MPW) which is proposed to improve the PSNR value as well as the level of watermarking security, when compared with MS-PW method.     

Acoustic Emission Monitoring of Hybrid FRP-Concrete Columns

Fiber-reinforced plastic tubes can be used as permanent formwork and external reinforcement for concrete columns. Failure of such columns is often accompanied by audible noise from cracking of concrete and shifting and settling of aggregates, snapping of the inner layers of the jacket, and ultimately fiber fracture. Since the state of the concrete core is not readily visible from the outside, nondestructive evaluation tools such as acoustic emission (AE) can help assess its structural integrity. The objective of this research was to investigate the applicability of AE technique to hybrid columns, and to correlate the AE parameters to the state of stress in concrete. The AE signature of hybrid columns was studied on over 40 specimens with different lengths, cross sections, jacket types, and jacket thicknesses. The study showed that (1) rate of change of cumulative AE counts with respect to the applied load correlates well with the degree of damage sustained by the concrete core; (2) longer specimens, thicker jackets, and unbonded tubes display higher AE activities; and (3) the Kaiser effect is not present in hybrid columns.     

MHD flow and heat transfer in a rectangular duct with temperature dependent viscosity and hall effect

In the present paper the laminar fully developed MHD flow and heat transfer through a rectangular duct of a viscous incompressible electrically conducting fluid is studied. A constant pressure gradient and an external uniform magnetic field are applied and the Hall effect is taken into consideration. The fluid viscosity is assumed to be temperature dependent with the assumption of constant wall heat flux axially and constant wall temperature peripherally. A numerical solution for the governing non-linear partial differential equations is obtained. The effect of the Hall term and the variable viscosity on the velocity and temperature fields is examined.     

A novel high-speed neural model for fast pattern recognition

Neural networks have shown good results for detecting a certain pattern in a given image. In this paper, faster neural networks for pattern detection are presented. Such processors are designed based on cross-correlation in the frequency domain between the input matrix and the input weights of neural networks. This approach is developed to reduce the computation steps required by these faster neural networks for the searching process. The principle of divide and conquer strategy is applied through matrix decomposition. Each matrix is divided into smaller in size sub-matrices and then each one is tested separately using a single faster neural processor. Furthermore, faster pattern detection is obtained using parallel processing techniques to test the resulting submatrices at the same time using the same number of faster neural networks. In contrast to faster neural networks, the speed up ratio is increased with the size of the input matrix when using faster neural networks and matrix decomposition. Moreover, the problem of local sub-matrix normalization in the frequency domain is solved. The effect of matrix normalization on the speed up ratio of pattern detection is discussed. Simulation results show that local sub-matrix normalization through weight normalization is faster than sub-matrix normalization in the spatial domain. The overall speed up ratio of the detection process is increased as the normalization of weights is done off line.     

Automated Data Acquisition for Bridge Inspection

Bridge management systems have a common need for a well-established inspection data acquisition system. Inspection data management requirements have expanded after establishment of new Federal Highway Administration regulations that require bridge inspection to be performed on an element-level basis. Currently, paper forms are the typical media used to record field-generated bridge inspection data. Better methods of data recording are needed to improve the accuracy and speed of the bridge inspection process. This paper discusses pen-based data acquisition technology and its potential in automating bridge inspection. The pen-based technology was utilized to develop an Automated Bridge Inspection System for the South Carolina DOT. As illustrated herein, the use of an automated inspection system simplifies the data processing effort, improves inspection data accuracy, and permits bridge inspectors to devote more time to the actual inspection process.     

Optimization of tramadol–PVC membrane electrodes using miscellaneous plasticizers and ion-pair complexes

Effect of the ISE membrane composition on the characteristics of the tramadol–PVC-electrodes has been investigated. The parameters studied include the effect of the plasticizer and the effect of the ion-pair complex. The plasticizers used were 2-nitrophenyl octyl ether (2-NPOE), dioctyl phthalate (DOP), dibutyl phthalate (DBP), tris(2-ethylhexyl) phosphate (TEPh), dioctyl sebacate (DOS), tributyl phosphate (TBPh) and dibutyl butyl phosphonate (DBBPh) and the ion-pair complexes were tramadolium–silicotungstate (TD–ST), silicomolybdate (TD–SM). These electrodes were fully characterized in terms of composition, life span, usable pH range and working concentration range. The results showed that the best combination was TD–ST as the ion-pair complex and DBP as the plasticizer that produced the electrode with favorable characteristics. Another electrode using TD–SM was tested and produced close results. The present electrodes show clear discrimination of tramadol hydrochloride from several inorganic, organic ions, sugars and some common drug excipients. The sensors were applied for determination of tramadol hydrochloride in urine, milk and pharmaceutical preparations using potentiometric determination, standard addition and the calibration curve methods. The results obtained were satisfactory with excellent percentage recovery comparable and sometimes better than those obtained by other routine methods for the assay.     

Superabsorbent nanocomposite hydrogels based on intercalation of chitosan into activated bentonite

Superabsorbent polymers, composed of acrylamide (Am) and 2-acrylamido-2-methyl-1-propane sulfonic acid, were prepared by the solution crosslinking polymerization technique. The effect of the ionic monomer content was correlated with the equilibrium swelling capacity. The swelling capacity was augmented up to 94?g/g by increasing the concentration of the ionic monomer. Intercalation of bentonite clay, by chitosan solution, was performed by two techniques, namely, microwave irradiation and heating. The basal spacing of bentonite increased from 1.21 to 1.31?nm for the former and to 1.4?nm for the latter. Specific interaction of bentonite with ?COH group of chitosan through hydrogen bonding was estimated by FT-IR. Also, TEM showed a layered morphology due to the penetration of chitosan chains into bentonite silicate layers. Different amount of the intercalated clay was dispersed in the aforementioned monomers aiming at preparing superabsorbent composites. The clay showed an exfoliated structure in the polymer matrix while the composite was porous, with a three-dimensional interconnected microstructure as proved by SEM. The prepared composites had a higher absorption capacity up to 180?g/g and a better thermal stability than the corresponding hydrogel.