Gold-catalyzed oxide nanopatterns for the directed assembly of Ge island arrays on Si

The heteroepitaxial growth of Ge on Au-patterned Si(001) is investigated using in situ spectromicroscopy. Patterning of a hydrogen-terminated Si surface with a square array of Au dots followed by brief exposure to air leads to the spontaneous, local oxidation of Si. The resulting oxide nanopattern limits the surface migration of Au during annealing up to 600 degrees C, resulting in complete preservation of the Au pattern. Subsequent deposition of Ge induces a redistribution of Au across the surface even as the oxide nanopattern persists. As a result, the oxide pattern drives the growth of Ge islands into an ordered assembly, while Au decorates the surfaces of the Ge islands and modifies their shape.     

Factors affecting virtual team performance in telecommunication support environment

Over the past two decades, many organizations have been taking advantage of globalization, outsourcing, and communication technology advances to enter new markets and compete wherever and whenever possible (Copeland, 2006). Telecommunication companies are among those companies that strive most to expand their customer base globally. Telecommunication industry is expected to grow on a worldwide basis to $2.7 trillion in 2017 (RCR Wireless, 2012). This global growth necessitates comparable expansion of support teams to service an expanded and distributed global customer base. Support function in the telecommunication industry has unique provisions and complex activities associated with troubleshooting customers’ networks. According to Williamson et al. (2004), troubleshooting customers’ networks involves complex activities such as making real-time traffic affecting decisions. Hence, identifying challenges that may face leaders in such complex and fast growing industry and factors that may influence the performance of support teams is critical. In addition, understanding the role and influence of leaders in virtual settings can help organizations in allocating resources and sorting teams’ priorities. In this study, we investigated factors that affect virtual team performance; factors considered include communication tools, cohesion and collaboration, leadership, trust, the location of team members and team size. One-hundred-twenty professionals in high-technology telecommunication industry participated in a survey to reveal the importance of how factors affecting virtual team performance. The findings indicated that support professionals perceived reliable communication tools and cohesion among team members as more significant performance factors than leadership.     

Integrated production planning and quality control for linear production systems under uncertainties of cycle time and finished product quality

This work considers serial production systems with several process steps and a possible quality control at final step. It deals with the problem of optimising planned lead time when the real lead time for each process is stochastic and the finished product quality is uncertain unless it is inspected. Three analytical models are proposed aiming to minimise the expected total cost, which is composed of the inventory and backlogging costs for the finished product and quality costs associated with inspection and non-conformities. These models correspond to three quality control policies: (i) without quality control, (ii) with quality control but without taking into account the inspection duration when optimising the planned lead time and (iii) with quality control and with considering the inspection duration when optimising the planned lead time. Based on the results, it can be highlighted the economic advantage of integrating quality control at the early stage of supply and production planning decisions for some cost parameters conditions. The robustness of the proposed models is also analysed regarding the variance of the probability distributions of the lead times.     

Two Analytical Approaches for Solution of Population Balance Equations: Particle Breakage Process

Various particulate systems were modeled by the population balance equation (PBE). However, only few cases of analytical solutions for the breakage process do exist, with most solutions being valid for the batch stirred vessel. The analytical solutions of the PBE for particulate processes under the influence of particle breakage in batch and continuous processes were investigated. Such solutions are obtained from the integro‐differential PBE governing the particle size distribution density function by two analytical approaches: the Adomian decomposition method (ADM) and the homotopy perturbation method (HPM). ADM generates an infinite series which converges uniformly to the exact solution of the problem, while HPM transforms a difficult problem into a simple one which can be easily handled. The results indicate that the two methods can avoid numerical stability problems which often characterize general numerical techniques in this area.     

A generic feature-independent pyramid multilevel model for Arabic handwriting recognition

Multimedia Tools and Applications - Over the last decade, several image features extraction schemes such as multi-level (ML) and pyramid multi-level (PML) have been proposed. Generally speaking,...     

A high-performance control algorithm based on a curvature-dependent decoupled planning approach and flatness concepts for non-holonomic mobile robots

Intelligent Service Robotics - This paper proposes a high-performance control strategy for an efficient manipulation of non-holonomic mobile robots in environments cluttered with static obstacles....     

Exploitation of vehicle's kinetic energy in power management of tow -wheel drive electric vehicles based on ANFIS DTC-SVM comparative study

The concept of the hybrid power system in electric vehicles means that there are many sources in this electric vehicle. The electric vehicle of two-wheel drives motors doesn't exploit the two front wheel; this kind of electric vehicle prompted us to propose using the front wheels in electric vehicle energy management, which creates another energy source. The hybrid vehicle can associate more than one source to each other to secure a long time working. The two rear wheels are generally controlled by classical controllers as the DTC-SVM controller that is one of many methods to control a motor's speed. It Based on three classical controllers. We want to replace the PI speed controller with an intelligent controller and show the possibility of integrating it in this kind of control. In this paper, we exploit the electric vehicle's Kinetic energy in energy management by combining the permanent magnet synchronous generator in the vehicle's front wheels, and integrating the ANFIS controller with back motors. The generator's power represents about 19% of the total electric vehicle power. The ANFIS management strategy gave the best résults 96.6 as efficiency and the smallest consumption of Air/fuel compared with the others methods about 55.75–199 (Ipm).     

Link failure resilience in the dynamic source routing protocol

Reactive routing protocols for mobile ad hoc networks reduce the routing cost in high mobility environments where link failures are frequent. However, route discovery in these protocols is typically performed via network‐wide flooding, which consumes a substantial amount of bandwidth and causes a significant latency to data packets. To improve the dynamic source routing (DSR) protocol and overcome these limitations, we propose two optimization techniques, viz. generalized salvaging mechanism and cache maintenance using a distributed topology discovery mechanism through mobile ant‐agents. We show, by simulations, that our contributions improve the DSR performance, and particularly in large scale networks with high mobility and heavy load that cause frequent link failures. Copyright © 2008 John Wiley & Sons, Ltd.     

Improving the Surface Electric Potential Measurement Capability for Textile Materials

The system currently employed for measuring the electric potential of the surface of textile fabrics consists in an electrostatic probe connected to an electrostatic voltmeter. The primary aim of the present work is to improve the capability of this measurement system, as evaluated by gauge repeatability and reproducibility studies. The experiments were conducted on samples of polypropylene non‐woven fabrics, electrostatically charged by exposing them to a negative corona discharge from a custom‐designed electrode system. A first series of fully operator‐controlled measurements pointed out the need to automatically control the relative position between the sample and probe, so that to eliminate the variability due to the non‐uniform structure of the non‐woven fabrics. The following series of partly automated experiments revealed that the repeatability and the reproducibility of the measurements are negatively affected by the decay of the electric potential at the surface of the samples. The best gauge capability is obtained when the measurements are delayed with respect to the moment of corona charging, in order to reduce the variability due to the fact that the samples characteristics change in time. Copyright © 2013 John Wiley & Sons, Ltd.     

Drift optimization of high‐rise buildings in earthquake zones

This paper presents a Drift Design Structural Model (DDSM) for the design optimization of high‐rise buildings in seismic zones. The model is formulated as a Generalized Single Degree of Freedom System subjected to equivalent static seismic loadings. The model objectives are: (a) the minimization of the structure weight; (b) the minimization of the structure top drift; and (c) the uniform distribution of the inter‐story drifts over the building height in order to minimize earthquake damage through the increase in plastic ductility. Seven high‐rise buildings were analysed in order to validate the model, to illustrate its use and to demonstrate its capabilities in structural design optimization in earthquake zones. The results obtained show that the DDSM performed well and consequently can be of practical value to structural designers. Copyright © 2009 John Wiley & Sons, Ltd.