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VLC (Visible Light Communications) technology represents nowadays a new paradigm that could have a significant impact on future wireless communications. Although this technology has many advantages, one of the most common problem generated by the use of optical communication systems (based on the light in the visible spectrum), is the increased degree of disruption of the communication channel under the direct sunlight influence. The purpose of this article is to present the technological developments specific to the VLC/IR-RF (Visible Light Communication / Infrared - Radio-Frequency) hybrid system developed in the framework of a scientific research project started in 2017, which were recorded during the first half of 2019. This system based on multiple sensory devices such as temperature, motion, light intensity, dust, IR and microbolometer sensors will present the ability of intelligent monitoring and control of indoor environments (houses, office buildings, universities, campuses, etc.). From the point of view of the final purpose of the project, this will result in a hybrid bidirectional optical communication system capable of supporting high transfer rates, increased resistance to the specific sunlight disturbance, and the possibility of transmitting sensory information over long distances. The previous experimentation activities undertaken during the project were based on the use of the Arduino UNO development boards. Currently, it has been chosen to replace them with the development boards based on the ARM Cortex-A53 processor, in order to improve the system's performance. The Arduino development boards have limited the performance of the communications system from the point of view of the transfer speeds and distances. The new Raspberry Pi development boards, being a complete operating and control system, presents high operational performances that can be used in favor of the final goal of the project. [ABSTRACT FROM AUTHOR]

Visual information plays an important role in almost all areas our life. Nowadays, much of this information is represented and processed digitally. Image processing is ubiquitous, with the applications ranging from Television (TV) to Computed Tomography, from Photography to Printing, from Robotics to remote sensing and medical applications. Ultrasound is one of the techniques for medical application. It is used for clinical usage. The most important technologies include transducers, beam forming, contrast agents, pulse compression techniques for measuring blood flow and three-dimensional imaging. Ultrasound imaging provides valuable imaging modality to provide the following functionalities as ease of use, low cost, safe, non invasive and fast examination. Ultrasound imaging system provides effective way for examining the various tissues of human body including thyroid, breast, abdominal organs, heart, muscles, tendons, arteries and veins. This paper aims to present on current segmentation algorithms used for medical images. Each and every type of algorithm is discussed as well as their main application fields identified. Experiments that apply the algorithms to segment ultrasound images are presented to further evaluate their behaviour. [ABSTRACT FROM PUBLISHER]

The use of small experiments as a tool for university teaching increases the student motivation, being considered useful elements for the improvement of the teaching and in particular skills, abilities, capacities and competences of the future engineer. This motive allows students manage his experience in the teaching/learning process while allowing to acquire a range of transverse competences that it can reveal in the course of their profession. At the same time, the development of small electronic devices is shown as a flexible, multidisciplinary science that adapts adequately to the objectives marked; on the one hand allows professors to implement various innovative teaching methods (Problem-Project Based Learning PBL, Challenge Problem CP, Case Method MdC,…) and on the other hand the student is clearly motivated to develop skills and competences related to this matter. Based on it, has been implemented a small application circuit destined to control commercial Radio-Frequency transceiver FM-433RF-RXQ1 that manages an operating frequency of 433,92 MHz in order to show to the student a simple application example of Industrial Electronic. [ABSTRACT FROM PUBLISHER]

We present a compact physics-based model of the current-voltage characteristics of graphene field-effect transistors, of especial interest for analog and radio-frequency applications where bandgap engineering of graphene could be not needed. The physical framework is a field-effect model and drift-diffusion carrier transport. Explicit closed-form expressions have been derived for the drain current covering continuosly all operation regions. The model has been benchmarked with measured prototype devices, demonstrating accuracy and predictive behavior. [ABSTRACT FROM PUBLISHER]

Recent years have been marked by the emergence of a wide variety of communication standards. The prevailing tendency is for global network convergence and wireless ubiquity. However, this leads to challenging design issues that have to be surmounted. Design methodologies and computer-aided design (CAD) tools currently in use suffer from significant shortcomings especially in radio-frequency (RF) microelectronics. Dependence of the design process on the underlying technology and the absence of high-level abstractions do not help designers. In this context, we propose in this paper a new design framework based on hardware abstraction in order to enhance design reliability and efficiency. Then, we discuss how this design framework can be a suitable response to the lacks of the conventional design schemes in RF and microelectronic systems. [ABSTRACT FROM PUBLISHER]

Efficient system-level design is increasingly relying on hierarchical design-space exploration, as well as compositional methods, to shorten time-to-market, leverage design re-use, and achieve optimal performances. However, in analog electronic systems, circuit behaviors are so tightly dependent on their interface conditions that accurate system performance estimations based on characterizations of individual stand-alone circuits is a hard task. Since there is no general solution to this problem, analog system integration has traditionally used ad-hoc solutions heavily dependent on designers' experience. In this paper, we build upon the analog platform-based design methodology by exploiting contracts to enforce correct-by-construction system-level composition. Contracts intuitively capture the thought process of a designer, who aims at guaranteeing circuit performance only under specific assumptions (e.g. loading and dynamic range) on the interface properties. Our approach allows automatic detection and composition of compatible components in a given library. We apply our methodology to an ultra-wide band receiver front-end to show that contracts allow pre-designed IP components to be smoothly integrated and design decisions to be reliably made at a higher abstraction level, both key factors to improve designer productivity. [ABSTRACT FROM AUTHOR]

Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas with bare metallic electrodes have shown their promising prospects in different fields. In this paper, based on the induced gas discharge approach, the discharge characteristics of RF, APGD plasmas using helium/oxygen mixture as the plasma working-gas are presented. The bio-medical effects of the helium RF APGD plasma jet acting on the gfp DNA and E. coli are also reported. Studies concerning the lethal and sub-lethal effects of the RF APGDs on the molecular and cell levels, which are related with the characteristics of the plasmas and their operation conditions are necessary in the future work based on a closer cooperation between the researchers in the field of the plasma science & technology and of the bio-medical science. [ABSTRACT FROM AUTHOR]

A superconducting 500-MHz cavity module has been installed into the electron storage ring of NSRRC. This SRF module is tested on both the RF and cryogenic performances, before and after installation into the electron ring. Calibrations and measurements on its cryogenic load at different operating helium bath pressures are described and concluded. The test results of unloaded quality factor are reported. Meanwhile the excellent regulation on helium bath pressure is so advantageous to all these measurements. During normal operation with RF power, fluctuations of the helium bath pressure and liquid helium level are +/- 1.38 mbar (0.02 psi) and +/-0.2%, respectively. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]