Search

The electronic structure and the transport phenomena of δ-MIGFETs have been studied in an AlxGa1−xAs host matrix. The subband structure and mobility calculations were performed within the effective mass approximation and relative mobility formula, respectively. Both the electronic structure and the transport properties are calculated as dependent on the applied magnetic field (B), the aluminum molar fraction (x) and the contact voltage in one of the gates (VC1). It was found that the mobility and conductivity are enhanced by increasing the magnetic field for appropriate aluminum molar fraction and contact voltage. In particular, the mobility (conductivity) is improved almost 26% (32%) for VC1 = 900 meV (850 meV), x = 0.2, and B = 20 T.

In this paper, a low cost, stand-alone and configurable data acquisition system with wireless communication to remote host is presented. The system allows recording up to eight multiplexed analog signals, with 12-bits resolution in variable ranges and a maximum sampling rate 11,500 S/s for each channel. The realization of the systems was done using FPGA as the main chip, and control multi-channel ADC chip to collect data. The data are transmitted to the host using wireless connectivity technologies Bluetooth or XBee, these data can be displayed and analyzed by computer application. The channels, sampling frequency and transmission rate can be configured by the user.

Various feedback strategies are proposed to improve the traffic flow. However, most of these works did not take road safety into consideration. In this paper, we studied the impact of four feedback strategies on the probability of rear-end collisions ([Formula: see text]). We proposed a new feedback strategy named Accidents Coefficient Feedback Strategy (ACFS) in which dynamic information can be generated and displayed on a board at the entrance of two-route scenario with intersection to help drivers to choose the appropriate road. This new strategy can greatly improve road safety and make the flow smooth as possible at the same time. Moreover, the impact of the intersection and boundary rates ([Formula: see text] and [Formula: see text]) on [Formula: see text] is also studied.

Using the Nagel-Schreckenberg model, we investigate the flow characteristics in a traffic circle system, where the entry lanes are controlled by traffic lights operating in a fixed-time ([Formula: see text]. We considered four different strategies to control traffic coming from [Formula: see text] entry lanes. We found that depending on the strategy used, four distinct traffic phases can appear in the circulating lane of the traffic circle, namely free flow, congestion, maximum current, and gridlock. Also, we investigate the origin of the gridlock phase in both cases (i.e. with/without traffic lights). Furthermore, the lengths of queues of stopped vehicles in the entry lanes were studied. We found that the traffic flow behavior on the exit/entry lanes depends strongly on the flow characteristics at the circulating lane as well as traffic lights strategy. To improve the operation of the traffic circle system, we have studied the time delay between the traffic lights to switch where all entry lanes go red, which allowing vehicles to clear the circulating lane.

In this paper, we propose a stochastic cellular automata model to study the traffic behavior at a single-lane roundabout. Vehicles can enter the interior lane or exit from it via [Formula: see text] intersecting lane, the boundary conditions are stochastic. The traffic is controlled by a self-organized scheme. It has turned out that depending on the rules of insertion to the roundabout, five distinct traffic phases can appear, namely, free flow, congestion, maximum current, jammed and gridlock. The transition between the free flow and the gridlock is forbidden. The density profiles are used to study the traffic pattern at the interior lane of the roundabout. In order to quantify the interactions between vehicles in the interior lane of the roundabout, the velocity correlation coefficient (VCC) is also studied. Besides, the spatiotemporal diagrams corresponding to the entry/exit lanes are derived numerically. Furthermore, we have investigated the effect of displaying signal ([Formula: see text], as the [Formula: see text] decreases, the maximum current increases at the expense of the free flow and the jamming phase. Finally, we have investigated the effect of the braking probability [Formula: see text] on the interior lane of the roundabout. We have found that the increase of [Formula: see text] raises the spontaneous jam formation on the ring. Thus, enlarges the maximum current and the jamming phase while the free flow phase decreases.