The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Time delay estimation (TDE) is one of the traditional methods in source location. TDE is used to derive the time difference of signal propagation from the source to the spatially separated sensors. Based on TDE a location algorithm of four-element array is express by matrix under the condition of low altitude and far field moving target. The best structure of four-element arbitrarily acoustic array...
We study a problem in which a single sensor is scheduled to observe sites periodically, motivated by applications in which the goal is to maintain up-to-date readings for all the observed sites. In the existing literature, it is typically assumed that the time for a sensor switching from one site to another is negligible. This may not be the case in applications such as camera surveillance of a border,...
This paper proposes a systematic approach of determining the optimal amplitude taper for a shared aperture linear array that possesses true-time-delay (TTD) multiple beam functionality. Conventionally, uniform taper is used to achieve maximum gain, while Taylor taper is widely used in low side lobe applications. However, when multiple beams are generated across ultra-wideband frequencies, they seem...
This paper presents an optimal design for gears considering gear transmission error, size and lubrication parameters and using Grey Relational Analysis Technique. For this purpose, a new approach has been utilized in order to calculate the transmission error in involute spur gears to get outputs in the shortest time with a high accuracy. In this model, a statically un-determined problem is considered...
Designing of the mathematical model is based on rigorous electromagnetic equations for antenna system as thin-wire dipoles above perfectly conductive screen which corresponds the given continuity restrictions. This model must consider mutual couple between screen's surface current j??s and current distribution of dipoles. It allows to calculate antenna system's pattern for arbitrary directions and...
An improved pattern synthesis algorithm based on optimization theory is proposed. The non-convex problem of array pattern synthesis with a dynamic range constraint in amplitude is converted to two convex formulations for optimization, and the amplitude of the optimal weight is confined to a certain dynamic range. The proposed method provides the optimal tradeoff among the mainlobe pattern, the sidelobe...
This work develops a maximum power point tracking (MPPT) algorithm for optimizing solar array performance that is robust to rapidly varying weather conditions. In particular, a novel extremum seeking (ES) controller, which utilizes the inverter ripple, is designed and tested on a simulated array with grid-tied inverter. The new algorithm is benchmarked against the perturb and observe (PO) method using...
Distributed generation in microgrid is mainly composed of new energy and renewable energy resources. The maximum power point of the PV cell array is various from time to time with the change of circumstance and load. The fuzzy control can react to the environment change quickly and keep the photovoltaic system work on its maximum power point all the time. However, the limitation in the fuzzy control...
Accurate data dependence testing allows a compiler to perform safe automatic code optimization and parallelization. It has been shown that factors, such as loop variants and nonlinear expressions, limit opportunity for data dependence testing and parallelization. Recently, the NLVI-Test has been introduced as new technology to enable exact data dependence testing on nonlinear expressions. Apart from...
This paper discusses the antenna phase centre trajectory (APCT) design for the sparse linear array 3-D imaging SAR(LASAR). Firstly, we introduce the signal model of the sparse LASAR. Based on the model, we discuss the 3-D ambiguity function (AF) of the sparse LASAR, and reveal the relationship between the 3-D AF and the system parameters. Finally, the distribution of the pseudo-random APCF is optimized...
This paper introduces a procedure for multi-objective optimization in antenna design. The problem described consists of the optimization of a seven element antenna array to improve the radiating performance. The three objectives considered are the minimization of the return loss, together with the minimization of the cross polarization and the mutual coupling between the ports; simultaneously, the...
Practical Halbach array is only close to ideal structure, hence it has to be optimized and improved before being used in project. In this paper new approaches are presented to optimize 8-piece linear Halbach array. By changing the length, width and magnetization direction, we can get stronger magnetic field with less magnet. Optimization indexes are presented to get the reasonable length of the module;...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.