Mohamed Abdelaziz

Pegylated interferon alpha-2b plus ribavirin in patients with genotype 4 chronic hepatitis C: The role of rapid and early virologic response.

In patients chronically infected with hepatitis C virus (HCV) genotype 4, the optimum duration of therapy and the predictors of sustained virologic response (SVR) have not been adequately determined. In this study, 358 patients with chronic hepatitis C genotype 4 were randomly assigned to pegylated interferon (PEG‐IFN) alpha‐2b (1.5 μg/kg/week) plus oral ribavirin (10.6 mg/kg/day) for a fixed duration of 48 weeks (control group, n = 50) or for a variable duration (n = 318). In the variable‐duration group, patients with undetectable HCV RNA at week 4 were treated for 24 weeks (group A, n = 69), patients with undetectable HCV RNA at week 12 were treated for 36 weeks (group B, n = 79), and the rest of the patients were treated for 48 weeks (group C, n = 160). The primary endpoint was SVR (undetectable HCV RNA 24 weeks after treatment cessation). Groups A‐C and the control group had SVR rates of 86%, 76%, 56%, and 58%, respectively. After the study was controlled for predictors, a low baseline histologic grade and stage were associated with SVR (P < 0.029) in all groups. In addition, among patients in group C, older age (P = 0.04), a higher baseline body mass index (P = 0.013), and low baseline HCV RNA (P < 0.001) were also associated with SVR attainment. The incidence of adverse events and the rate of discontinuation were higher in patients in the variable‐duration and fixed‐duration groups treated for 48 weeks. Conclusion: In patients with chronic hepatitis C genotype 4 and undetectable HCV RNA at weeks 4 and 12, treatment with PEG‐IFN alpha‐2b and ribavirin for 24 weeks and 36 weeks, respectively, is sufficient. (HEPATOLOGY 2007.)

Hybrid cluster of multicore CPUs and GPUs for accelerating hyperspectral image hierarchical segmentation

Hierarchical image segmentation is a well-known image analysis and clustering method that is used for hyperspectral image analysis. This paper introduces a parallel implementation of hybrid CPU/GPU for the Recursive Hierarchical Segmentation method (RHSEG) algorithm, in which CPU and GPU work cooperatively and seamlessly, combining benefits of both platforms. RHSEG is a method developed by National Aeronautics and Space Administration (NASA) which is more efficient than other traditional methods for high spatial resolution images. The RHSEG algorithm is also implemented on both GPU cluster and hybrid CPU/GPU cluster and the results are compared with the hybrid CPU/GPU implementation. For single hybrid computational node of 8 cores, a speedup of 6x is achieved using both CPU and GPU. On a computer cluster of 16 hybrid CPU/GPU nodes, an average speed up of 112x times is achieved over the sequential CPU implementation.

Development of integrated brakes and engine traction control system

Traction control system (TCS) helps regulating wheel slip when vehicle starts from rest or accelerates excessively. It limits the slip either by applying braking torque or suppressing the engine torque or by using both techniques. The brakes has faster response than the engine; however, overusing brakes decrease its lifetime and increase the fuel consumed. In this paper, a TCS is proposed that utilizes both the brakes and the engine to control the wheel slip. Fuzzy and PID control strategies are used to control the brakes and engine respectively. When slip exceeds a certain threshold, the brakes TCS is activated, after a couple seconds the control is switched smoothly to the engine TCS and then the Brakes TCS is deactivated. The controller design was verified through simulations on the Simulink environment. The results show that the controller is able to maintain slip ratio at the desired value with smooth transition during switching controllers in addition to its capability of coping with sudden change in road conditions.

GPU implementation for hyperspectral image analysis using Recursive Hierarchical Segmentation

Graphics processing units (GPUs) have recently emerged as a promising parallel architecture considering the rapid growth of its computational power in comparison with uniprocessors. In this paper, we investigate a GPU parallel implementation of Recursive Hierarchical Segmentation technique (RHSEG). RHSEG is an object-based image analysis (OBIA) segmentation technique which involves region growing and spectral clustering (non-adjacent region growing). OBIA is becoming more popular compared to traditional pixel-based image analysis because of its efficiency with high spatial resolution images. The proposed parallel RHSEG algorithm was implemented using NVidias compute device unified architecture (CUDA). The experiments conducted show that the parallel GPU RHSEG achieved an average processing speedup of 3.5 times over the sequential CPU implementation.

Metaheuristic optimization in path planning of autonomous vehicles under the ATOM framework

Autonomous transportation systems are embarking our lives at an increasing pace. Over the past few years, several commercially available vehicles are incorporated with increasing levels of autonomy. The Autonomous Transportation Operating Modules (ATOM) framework is proposed to organize and coordinate the development as well as testing of these autonomous systems. One of the most important modules is the path planning of the vehicle, and finding the optimal path between two points is of great importance as it is directly to power saving of the battery. Metaheuristic optimization techniques are widely used to solve complex problems in an acceptable time interval. In this study, three metaheuristic approaches; simulated annealing, particle swarm and ant colony optimization are investigated to find the optimal path between two points in a static environment. The results of the PSO outperformed the other two, opening the door for investigating its implementation on the embedded level for further demonstration and testing on real experimental platforms.

Design and performance analysis of hybrid fuzzy robust controller for hydraulic system against variable loads

The continuous motion of hydraulic implements in industrial is important parameters which affect productivity of mould casting machine. A lab setup is designed to evaluate a position control technique of a hydraulic cylinder at different load patterns. The lab setup consists of two loops, the first loop represents the controlled cylinder and the second loop represents the control of the loading cylinder. Robust and hybrid fuzzy robust controllers are developed to reduce the synchronization errors in cylinders positions to acceptable values. The second loop is controlled so that simulates variable loads with different pattern. A model representing the lab setup is developed and the system response is verified using experimental results.

Securing Relational Databases with an Artificial Immunity Features

Database security is considered one of the major computer science research trends because of its importance in maintaining the privacy, integrity, and confidentiality of data. Human immune system is a set of defense mechanisms that can be used to defend the body against diseases caused by pathogens. Artificial immune system is the artificial simulation of human immunity that can be applied to computer security applications. The main goal of this paper is to develop a database security system based on danger theory. Danger theory is one of the most recent algorithms of artificial immunity that can provide interactive features for securing relational databases. By merging the developed features of artificial immunity to the security system, the secrecy of the database can be maintained.

Integrating Encrypted Mobile Agents with Smart Homes

Smart homes have come into reality with the integration of many technologies to provide maximum satisfaction to their inhabitants. In this paper, we present a new approach for resources management in multi-inhabitant smart homes using encrypted mobile agents. Mobility is combined with encryption in order to provide maximum privacy to the inhabitants. Conflict resolution on smart devices control is also considered between agents. The efficiency of our approach would be evaluated using our smart space simulation tool, Bosthan.