This paper describes the design and fabrication of an intelligent gate system that allows only certain vehicles or cars passing through the gate. It is very important to design an intelligent gate to control the flow of entered people or vehicles to the premises. The gate system should have capabilities to control the gate, where only specified vehicles or cars are allowed to enter the premises. The gate will open when the known vehicles are identified. The gate will not open if unauthorized vehicles try to pass. The system is a combination of mechanical, electrical and electronic components. It is one of the mechatronics engineering products. This intelligent gate system is suitable to be installed at universities, companies where only certain vehicles are allowed to enter. The list of certain vehicles must be stored in the database of the system. When the unknown vehicles try to pass through the gate, the gate will show a warning signal to the driver that they are unauthorized.

This paper predicts the effect of the user’s hand-hold position on the Total Isotropic Sensitivity (TIS) of GSM900/1800 mobile phone antennas of realistic in-use conditions, where different semi-realistic mobile phone models, i.e., candy bar and clamshell, as well as different antenna types, i.e., external and internal, are simulated using a FDTD-based platform. A semi-realistic hand model consisting of three tissues and the SAM head are used in simulations. The results show a considerable impact on TIS of the adopted mobile phone models owing to the user’s hand presence at different positions, where a maximum level of TIS is obtained while grasping the upper part of the mobile phone against head. Maximum TIS levels are recorded in talk position for mobile phones with external antenna and maximum differences in TIS levels due to the hand-hold alteration are recorded for clamshell-type phones.

Using Verilog Hardware Description Language to teach Computer Architecture Courses

This paper investigates both the computation accuracy (based on the power balance error) and the cost in terms of the number of FDTD-grid cells due to the artifact rotation for a cellular handset close to the user’s head. Two study cases are simulated to assess the EM coupling of a cellular handset and a MRI-based human head model at 900 MHz; firstly, both handset and head CAD models are aligned to the FDTD-grid, secondly, handset close to a rotated head in compliance with IEEE-1528 standard. A FDTD-based platform, SEMCAD-X, is used; where conventional and interactive gridder approaches are implemented to achieve the simulations. The results show that owing to the artifact rotation, the computation error may increase up to 30%, whereas, the required number of grid cells may increase up to 25%

As software systems grow, their complexity augments dramatically. In consequence their understandability and evolvability are becoming a difficult task, therefore a way to describe the architecture of software systems is becoming a must. The architecture of a software system can be described using either an architecture description language (ADL) or an object-oriented modeling language. In this article, we show how we can build a hybrid model, based on the two approaches, to describe the architecture of software systems. This approach profits from the advantages of the two approaches, i.e. the explicit presentation of functional aspects in object-oriented modeling and the explicit separation of competition (components) from interactions (connectors) in architectural description.

Significant challenges has been introduced for IP networks with the advent of new emerging applications, such as VOIP and E-Commerce, that require delivering quality guarantees. However, IP networks were originally designed to support best effort delivery only. Two Quality of Service (QoS) standard models, IntServ, DiffServ have been standardized by the Internet Engineering Task Force (IETF). Although these methods guarantee delivery, they have drawbacks such as complexity, restrictions of predefined classes and higher end-to-end delay. In this paper, a new QoS mathematical model has been proposed. This model is based on the principles of Network Calculus in which an incoming traffic flow is regulated by an arrival curve that upper bounds its rate. Then, this traffic flow is lower bounded and delayed by a service latency time at each node on its way to the destination node. The worst case end-to-end delay is derived and illustrated by a numerical example. The proposed model has achieved acceptable end-to-end delay compared with the other models.

Abstract

This paper presents the effect of corrugation geometry on the crushing behavior, energy absorption, failure mechanism, and failure mode of woven roving glass fibre/epoxy laminated composite tube. Experimental investigations were carried out on three geometrical different types of composite tubes subjected to axial and lateral compressive loadings. On the addition to a radial corrugated composite tube, cylindrical composite tube, and corrugated surrounded by cylindrical tube were fabricated and tested under the same condition in order to know the effect of corrugation geometry. The results showed that the loading carrying capability is significantly influenced by corrugation geometry in axial crushing. However, no affect of corrugation geometry was observed for lateral crushing. Load–displacement curve was plotted for all conducted tests, thus clear comparison between different specimen's geometry was achieved. It is also found that radial corrugation could significantly applicable as a stable and effective energy absorber.

Abstract

A numerical simulation of a two-stage reciprocating compressor has replicated the operations of the compressor under various conditions for the development of diagnostic features for predictive condition monitoring. The simulation involves the development of a mathematical model of five different physical processes: speed–torque characteristics of an induction motor, cylinder pressure variation, crankshaft rotational motion, flow characteristics through valves and vibration of the valve plates. Modelling both valve leakage and valve spring deterioration has also been achieved. The simulation was implemented in a MATLAB environment for an efficient numerical solution and ease of result presentation. For normal operating conditions, the simulated results are in good agreement with the test results for cylinder pressure waveforms and crankshaft instantaneous angular speed (IAS). It has been found that both the IAS fluctuation and pressure waveform are sensitive detection features for compressor faults such as valve leakage and valve spring deterioration. However, IAS is preferred because of its non-intrusive measurement nature. Further studies using the model and experiments are being undertaken in order to develop fault detection features for compressor driving motors and transmission systems.