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An analysis of the video capabilities of multiple antenna LTE networks

Abstract

LTE technology has been designed to serve high data traffic and to withstand occasional traffic bursts caused by various events that arise when live video streams are watched. LTE will have to manage its resources judiciously since video traffic is not constant, and at the same time it will have to seek to offer highest quality experience. This paper demonstrates the benefits of using MIMO technique with 4 transmitters instead 2 when requesting live video streams. It also displays mobility cases each with a different subscriber moving speed, and with different gains, respectively.

Open access
Automated evaluation of agricultural damage using UAV survey

Abstract

In the last decade modern agriculture used significant resources for automated evaluation. Game damage and crop evaluation and prediction are the main focus of the precision agriculture. At John von Neumann Faculty of Informatics, Óbuda University, Hungary, researchers together with agricultural experts are developing automated evaluation methods for high-resolution survey data. With the locally developed unmanned aerial vehicles (UAVs) the agricultural survey can be easily done for 1-2km2 area from a single flight.

The paper presents the detailed method of the early steps of the automated evaluation using Matlab and the comparison of results to the GIS data.

Open access
Bimodal RMS distributions for the objective detection of theta (θ) and gamma (γ) brain oscillations during long-term continuous LFP recordings in mice

Abstract

In the rodent’s brain the theta (5-12 Hz) and gamma (30-120 Hz) oscillations can be readily detected in local field potential (LFP) recordings, but there is no universal consensus about an objective threshold for their detection.

We FIR-filtered the long-term local field potential (LFP) recordings for theta and gamma oscillations. The RMS (root mean square) values of 8 s epochs in 0.5-4 s steps (using corresponding overlaps) were obtained from the filtered recordings. For both theta and gamma oscillations, the histograms showed a bimodal distribution well fitted by two Gaussians. The point of intersection between the two distributions proved to be the most reliable for separating the RMS values belonging to the two Gaussians.

Open access
Communication Protocol for Wireless Sensor Network, Dedicated for Real Time Biosignal Acquisition, Implemented on Top of Contiki OS

Abstract

The aim of this paper is to present a communication protocol designed for Wireless Sensor Network based biosignal measurement system. The protocol addressees the issue of time synchronization of the measuring nodes and real time transmission of the acquired measurements. We run the Contiki OS on the sensor nodes and the protocol was implemented as a process. The proposed protocol was tested on custom built hardware, developed by our team for biosignal measurement.

Open access
Comparative FEM Analysis of Gears Modeled With Analytical, Solid Subtracting and Mixed CAD Generating Method

Abstract

The paper proposes a comparative FEM analysis of gears solid model bodies, obtained with three different methods. The analytical method is based on the mathematical equations of the tooth flanks. It supposed to be the most accurate and precise solid modeling process. However, it reveals it’s limits by handling of surfaces that are not deduced mathematically, or in case of tooth geometries which needs to be modified in order to perform a quick test regarding the probably effects of the mentioned modifications. The solid subtraction- and the newly developed, mixed CAD method are pure CAD generating methods. As any discrete generating method, their precision is influenced by the fineness of the iteration steps. In case of the mixed CAD solution the precision is influenced by the filtering algorithm applied to the generated Points Cloud. The visual comparison of the three mentioned methods, was presented in previously published papers. The present paper validates the novel mixed CAD method comparing the FEA analysis of the generated solid models.

Open access
Computing Algorithm for the Gear Tooth Space Points Cloud Envelope Generated by the Mixed Cad Method

Abstract

The task of the mixed pure CAD generating method developed by the authors consists in finding only the points situated on the gear tooth surface. The use of the mixed CAD gear generating method results in a very large and particular type of Points Cloud: This contains points situated both in the tooth space, and on the tooth surface. The existing filtering programs and methods, as it was presented in previous papers, cannot deal with these particular point sets. The development of the named particular generating method claims an algorithm and a computer software which can find the envelope of the Points Cloud. This papers presents an Alpha Shape algorithm based filtering algorithm, adapted and developed to be used together with the mixed CAD generating software.

Open access
Digitally Controlled AC Current Measurement and Protection Techniques

Abstract

This paper describes a cost effective AC current measurement method that avoids complex AC to DC current measurements by converting an amplified and rectified AC voltage drop across a shunt resistor to a duty cycle of a PWM signal. The current measurement chain output is fed into a microcontroller unit (MCU) and into a short circuit protection block that inhibits AC load drivers in case of overcurrent or short circuit events, overriding the state set by the MCU control algorithm. The authors present a mathematical model, simulations and a practical evaluation of custom-developed circuits that are capable to reach a convincing level of measurement precision. By counting a given number of consecutive AC periods, the effect of inrush current generated by inductive AC loads is filtered. The proposed solution allows inrush currents up to 3A, fitting the consumption range of AC control elements met in household application circuits, such as relays or solenoid valves.

Open access
DMA tests for 3D printed polymer specimens of fatigue test examination

Abstract

Alongside the using of „technical materials’, the direct 3D printed different plastic also speeded up lately. Accordingly to this, it is often designed parts, which have to sustain extreme stress. The proper definition of material qualities is expensive; despite in every phase of designing, we need it to be done perfectly. In every industrial section, it is important to work with exact material characteristics, especially in fields where strict safety rules have to be kept (in connection with the lifespan) the design of fatigue tests of 3D printed polymer specimens. We planned the examinations on the way to avoid the critical temperature range shown by the DMA examinations’ results in the bending point of the inner friction coming up in the local range. This information could be important for the Military to change the busted parts quickly and sound. That is the reason why we designed these examinations in this way, so, it could help for designers in the field of military, in development of security technology and improvement of recovery.

Open access
Evaluation and Comparison of Low FPGA Footprint, Embedded Soft-Core Processors

Abstract

The paper presents three embedded soft-core processor architectures, developed by the authors to be easily implementable while yielding low digital resource usage. These architectures will be compared and contrasted between each-other by introducing a special testing method, based on control algorithm implementations. For reference, the same testing and comparison has been implemented on a well established architecture, too, on the Xilinx PicoBlaze processor. Measurement results and application suggestion are given in the concluding section.

Open access
Finger or Stylus: Their Impact on the Performance of On-line Signature Verification Systems

Abstract

The widespread use of smartphones and the ability of these devices to digitize signatures have made it possible to sign electronic documents in this way. In this paper we compared two on-line signature databases in terms of verification performance: the MCYT containing signatures drawn by stylus pen, and MOBISIG containing finger drawn signatures. Performance evaluations were performed using both local and global systems. In the case of global systems, we evaluated the performance of a novel information theory features set. Little improvement was achieved by this feature set. There were large differences between the two databases in terms of performance. Finger drawn signatures collected by mobile device were proved inferior to signatures collected by digitizing tablet and its stylus.

Open access