This paper gives an overview of the issues in the choice of a coordinate system in the case when multiple target are tracked using multiple sensors. In modern target tracking systems, tracking is based on results obtained using some of the target state estimation algorithms. These algorithms involve equations describing the target movement and the measurement process. The existence of different coordinate systems requires appropriate transformations in the state estimation process. In some algorithms this decreases the state estimation accuracy. Since numerous calculations have to be done, a problem may occur in real-time implementation of these algorithms. The goal of this paper is to emphasize the relevant facts that must be taken into consideration during the planning and development of multiple targets multiple sensors tracking (MTSTT) systems.
In this paper the systems of classic passive radar detection of radar targets are analyzed and the requests of superposition of two very close radar targets are defined. Also, there are analyzed reference methods of superposition based on the angle determination of incoming electromagnetic waves by waves sampling and determination of signal power spectrum as a function of space frequency in the presence of angular noise (clutter). By sampling a number of footprints of signals and by the estimation of the space frequency and the co variation matrix of received useful signals and noise, it is possible to repeat accurately necessary information about the resolution of two close targets at the sensor of the antiradar missile homing head. After comparing required and gained parameters: accuracy of direction standard deviation of direction, accuracy of separation of two sources and probability of reliable separation, it is recommended in the paper to use a modified method of maximum entropy, as the best method for the separation of two angular very close targets that are seen by the homing head of the antiradar missile.
Today's and future telecommunication networks must enable transmission throughout heterogeneous environment, using different Quality of Service protocols, Quality of Service protocols use a variety of complementary mechanisms to enable deterministic end-to-end different data delivery. The analysis of these protocols and their efficiency in providing QoS and CoS has been given in this paper.
In the years to come, variety of devices, from cell phones and laptops to personal digital assistants and household appliances, will be capable of communicating and interoperating with one another using a new high-speed low-power microwave wireless link technology called Bluetooth. The overview of this technology, standardization and application of Bluetooth are the contents of this paper.
This paper describes architecture, design, and implementation of Code Tutor a Web-based intelligent tutoring system that facilitates learning of radio communications to the students of a telecommunications college. Code Tutor designed as a Web classroom client-server system, is ontologically founded and built using modern intelligent and Web-related technologies. Experience with Code Tutor so far shows that both teachers and learners have positive feelings about using Code Tutor as a support tool for learning different topics in the domain. In order to illustrate the use of Code Tutor in practice, the paper also presents some details of both students' and teachers' sessions with the system.
Acetone vapors influence on the double base propellant mechanical properties and the burning rate is shown and analyzed. Mechanical investigations were done with uniaxial tensile and impact tests. Burning rate investigations were carried out in the manometric bomb and rocket motors. The obtained results of the investigations show a significant acetone vapors influence on mechanical properties without a significant influence on the burning rate.
The concept of heavy motor vehicles exerts influence on their dynamic parameters. Some dynamic parameters also depend on the load position with respect to load space. In this paper, the effects of the load position, i.e. the center of gravity on dynamic parameters of trucks have been analyzed. Besides the dynamic parameter variation analysis, the first order sensitivity functions have been given as well. The influence of changing the center of gravity position in the longitudinal direction on vertical oscillations as well as changing the position of the center of gravity in the lateral direction on angular oscillations have been noticed.
Intensive research for decreasing fuel consumption of 1C engines is due wainly to ecologycal reasons. The problem can be solved by applying numerous diferent design solutions, among them methods for friction decrease. In order to achieve any success in that field it is necessary to be familiar with tribological features of a complete engine and its individual parts and assemblies. The main influence on 1C engine friction losses comes from the piston group, the cranckshaft bearings, the timing system and the lubrication system. Tribological characteristics have to be determined in the first stage of 1C engine design, because this is the only way to give full contribution to the decreasing of fuel consumption and exhaust emission.
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