The last few decades, a great deal of attention has been paid to low-voltage (LV) low-power (LP) integrated circuits design since the power consumption has become a critical issue. Among many techniques used for the design of LV LP analog circuits, the Bulk-driven principle offers a promising route towards this design for many aspects mainly the simplicity and using the conventional MOS technology to implement these designs. This paper is devoted to the Bulk-driven (BD) principle and utilizing this principle to design LV LP building blocks of Current Mirror (CM), Enhanced Current Mirror (ECM), Operational Transconductance Amplifier (OTA), Current Conveyor (CCII) and Current Differencing Transconductance Amplifier (CDTA) in standard CMOS processes and supply voltage ±0.7 V. The simulation results have been carried out by the Spice simulator using the 0.25 μ CMOS technology from TSMC.
To adapt to current changes, such as globalization, climate change, and demographic growth, modern cities must embrace the digitalization of city management. In this paper, we examine a concept for digitalizing a city based on Rotterdam’s digital twin showcase. Data-processing frameworks for different sources of data are presented. Security risks and the potential of smart cities for military usage are discussed. Lastly, using an example of available datasets for air quality and public lighting consumption, functions of the Rotterdam digital twin are compared with the Brno city digital platform. It was found that every city has its approach to digitalization, and it is probably impossible to unify every city’s digitalization process. This means that the digitalization of the city is very individual. Both systems in their current form make it possible to visualize the collected data about the city. So far, however, these systems do not use advanced functions such as AI-assisted decision-making and prediction of various events in the city. Even so, they are a source of very interesting data that can be used by third parties.
The ever-increasing demands for the use of fiber-optic sensors powered by long optical fibers is forcing developers to solve problems associated with powering these remote sensors. Due to their non-electric character, these sensors are suitable for many uses, including military applications. The Army of the Czech Republic is very interested in this type of optical fiber sensor as it fulfils the significant prerequisites for use in military areas. However, the army’s requirements are challenging because they require long supply cables in which there is significant attenuation of optical power. At the same time, there is a need for high sensitivity. The subject of our research team’s work was to use amplifiers to power these sensors. The army already uses this type of sensor for short distances as it cannot ignite a gas mixture with an explosive concentration and thus meet the strict requirements of the explosion-poof standard. The novelty of our research lies in the discovered measurement technique that allows the sensors to be powered remotely and in the saving of optical fibers by utilizing duplex communication with a circulator. Furthermore, the research presents an innovative approach to the optimization of the entire sensor by using a bidirectional, sensory, polarization-maintaining optical fiber. The proposed sensor was first verified in laboratory conditions at the Optoelectronics Laboratory of the University of Defense in Brno, and further tests were carried out in the military training areas of Boletice and Březina in the Czech Republic, which is a member of North Atlantic Treaty Organization.
24 July 2012 in Analog Integrated Circuits and Signal Processing
The application in polarization sensor systems uses changes in the polarization of light in the optical fiber during temperature changes. The principle of operation consists in the specific propagation of polarized light by special optical fibers, which, thanks to their construction, keep the light in two axes, but change the speed of their propagation and thus the instantaneous state of light polarization. It has been shown that by suitable methods it is possible to transform changes in the polarization of light into changes in its intensity, which can be detected very efficiently and quickly by a photodiode. This method has been practically verified, implemented by fiber components and confirmed as suitable for the implementation of a fiber sensor of thermal field disturbance. However, it turns out that especially in military and biomedical applications it is impossible to place a source of optical radiation close to the measured subject and the sensor must be powered remotely using optical fibers of the order of kilometers. This paper shows the possibility of using long optical paths to power the polarization sensor.
Two-ports for mutual transformation between flux-controlled memristors and charge-controlled memristors are proposed. Attention is paid to memristors with the region of negative differential memristance in the charge-flux constitutive relation, when such a transformation should be made carefully. Connections between this transformation, duality rules, and Chua’s table of higher-order elements are described. The proposed transforming cells can be made up of commercially available integrated circuits. Their proper operation is demonstrated via simulations and lab experiments with memristive oscillators.