arXiv subjects

Robert Mingesz

Publications and source records attributed to Robert Mingesz.

18 recordsLinked to original sources

arXiv2019

Voltmeter in series?

A recent physics challenge shows a circuit, where a voltmeter is connected in series. Indeed, real voltmeters have finite input resistance, therefore one may think that they can be used as resistors. In addition, voltmeters measure the voltage difference between their terminals, therefore it seems to be possible to calculate the current flowing through them. Is it okay? Does it make the voltmeter more universal? Are there any hidden secrets? How it is related to high-quality physics and STEM education, which are increasingly important in the modern world? Doesn't it approve an improper use that one can never see in any textbook and application? Suggesting and teaching such uncommon solutions doesn't generate undesired attitude? On the other hand, can it make the development of creativity and understanding harder if the students are taught to follow always the application rules? We do think it bears some discussion.

physics.ed-ph↗

arXiv2019

Comment on "Resistance of a digital voltmeter: teaching creative thinking through an inquiry-based lab"

Teaching about measurements and showing examples of instruments' non-ideal behaviour are important in physics education. Digital multimeter input impedance analysis is perfect for this, since these instruments are easily available, precise enough, have good value/price ratio and represent modern technology. A recent paper (2018 Phys. Educ. 53 053005) demonstrates how the investigation of the input impedance of a digital multimeter can be used in education. However, we think that some more discussion is needed to make it more complete.

physics.ed-ph↗

arXiv2019

How accurate is an Arduino Ohmmeter?

The Arduino platform is widely used in education of physics to perform a number of different measurements. Teachers and students can build their own instruments using various sensors, the analogue-to-digital converter of the Arduino board and code to calculate and display the result. In several cases this can mean incautious reproduction of what can be found on the Internet and an in-depth understanding can be missing. Here we thoroughly analyse a frequently used resistance measurement method and show demonstration experiments as well to make it clear.

physics.ed-ph↗

arXiv2019

Universal Arduino-based experimenting system to support teaching of natural sciences

The rapid evolution of intelligent electronic devices makes information technology, computer science and electronics strongly related to the teaching of natural sciences. Today almost everybody has a smart phone that can convert light, temperature, movement, sound to numbers, therefore all these can be processed, analysed, displayed, stored, shared by software applications. The fundamental question is how education can follow this knowledge and how can education take its advantages. Components and methods of modern technology are available for education also, teachers and students can play with parts and tools which were previously used only by engineers. A good example is the very popular Arduino board which is practically an industrial microcontroller whose pins are wired to easy-to-use connectors on a printed circuit board. In this paper we show a universal system which we have developed for the Arduino platform to support experimenting and understanding of the most fundamental principles of the operation of modern devices. We show our related educational concept and discuss the most important features of the system. Open source hardware and software are available and we provide a number of video tutorials as well.

physics.ed-ph↗

arXiv2015

Random noise can help to improve synchronisation of excimer laser pulses

Recently we have reported on a compact microcontroller-based unit developed to accurately synchronise excimer laser pulses (Robert Mingesz et al, Fluct. Noise Lett. 11, 1240007 (2012), DOI: 10.1142/S021947751240007X, arXiv:1109.2632). We have shown that dithering based on the random jitter noise plus pseudorandom numbers can be used in the digital control system to radically reduce the long-term drift of the laser pulse from the trigger and to improve the accuracy of the synchronisation. In this update paper we present our new experimental results obtained by the use of the delay controller unit to tune the timing of a KrF excimer laser as an addition to our previous numerical simulation results. The hardware was interfaced to the laser using optical signal paths in order to reduce sensitivity to electromagnetic interference and the control algorithm tested by simulations were applied in the experiments. We have found that the system is able to reduce the delay uncertainty very close to the theoretical limit and performs well in real applications. The simple, compact and flexible system is universal enough to be used in various multidisciplinary applications as well.

physics.ins-det↗

arXiv2015

Generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system using arbitrary resistors

The Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system has been introduced as a simple, very low cost and efficient classical physical alternative to quantum key distribution systems. The ideal system uses only a few electronic components - identical resistor pairs, switches and interconnecting wires - to guarantee perfectly protected data transmission. We show that a generalized KLJN system can provide unconditional security even if it is used with significantly less limitations. The more universal conditions ease practical realizations considerably and support more robust protection against attacks. Our theoretical results are confirmed by numerical simulations.

cs.CR↗

arXiv2014

Analysis of an attenuator artifact in an experimental attack by Gunn-Allison-Abbott against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system

A recent paper by Gunn-Allison-Abbott (GAA) [L.J. Gunn et al., Scientific Reports 4 (2014) 6461] argued that the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system could experience a severe information leak. Here we refute their results and demonstrate that GAA's arguments ensue from a serious design flaw in their system. Specifically, an attenuator broke the single Kirchhoff-loop into two coupled loops, which is an incorrect operation since the single loop is essential for the security in the KLJN system, and hence GAA's asserted information leak is trivial. Another consequence is that a fully defended KLJN system would not be able to function due to its built-in current-comparison defense against active (invasive) attacks. In this paper we crack GAA's scheme via an elementary current comparison attack which yields negligible error probability for Eve even without averaging over the correlation time of the noise.

cs.CR↗

arXiv2014

What kind of noise guarantees security for the Kirchhoff-Loop-Johnson-Noise key exchange?

This article is a supplement to our recent one about the analysis of the noise properties in the Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system [Gingl and Mingesz, PLOS ONE 9 (2014) e96109, doi:10.1371/journal.pone.0096109]. Here we use purely mathematical statistical derivations to prove that only normal distribution with special scaling can guarantee security. Our results are in agreement with earlier physical assumptions [Kish, Phys. Lett. A 352 (2006) 178-182, doi: 10.1016/j.physleta.2005.11.062]. Furthermore, we have carried out numerical simulations to show that the communication is clearly unsecure for improper selection of the noise properties. Protection against attacks using time and correlation analysis is not considered in this paper.

cs.CR↗

arXiv2014

Noise properties in the ideal Kirchhoff-Law-Johnson-Noise secure communication system

In this paper we determine the noise properties needed for unconditional security for the ideal Kirchhoff-Law-Johnson-Noise (KLJN) secure key distribution system using simple statistical analysis. It has already been shown using physical laws that resistors and Johnson-like noise sources provide unconditional security. However real implementations use artificial noise generators, therefore it is a question if other kind of noise sources and resistor values could be used as well. We answer this question and in the same time we provide a theoretical basis to analyze real systems as well.

cs.CR↗

arXiv2014

Power spectral density estimation for wireless fluctuation enhanced gas sensor nodes

Fluctuation enhanced sensing (FES) is a promising method to improve the selectivity and sensitivity of semiconductor and nanotechnology gas sensors. Most measurement setups include high cost signal conditioning and data acquisition units as well as intensive data processing. However, there are attempts to reduce the cost and energy consumption of the hardware and to find efficient processing methods for low cost wireless solutions. In our paper we propose highly efficient signal processing methods to analyze the power spectral density of fluctuations. These support the development of ultra-low-power intelligent fluctuation enhanced wireless sensor nodes while several further applications are also possible.

physics.ins-det↗

arXiv2014

Current and voltage based bit errors and their combined mitigation for the Kirchhoff-law-Johnson-noise secure key exchange

We classify and analyze bit errors in the current measurement mode of the Kirchhoff-law-Johnson-noise (KLJN) key distribution. The error probability decays exponentially with increasing bit exchange period and fixed bandwidth, which is similar to the error probability decay in the voltage measurement mode. We also analyze the combination of voltage and current modes for error removal. In this combination method, the error probability is still an exponential function that decays with the duration of the bit exchange period, but it has superior fidelity to the former schemes.

cs.CR↗

arXiv2012

Johnson(-like)-Noise-Kirchhoff-Loop Based Secure Classical Communicator Characteristics, for Ranges of Two to Two Thousand Kilometers, via Model-Line

A pair of Kirchhoff-Loop-Johnson(-like)-Noise communicators, which is able to work over variable ranges, was designed and built. Tests have been carried out on a model-line performance characteristics were obtained for ranges beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and security performance of the exchanged raw key bits. This simple device has single-wire secure key generation and sharing rates of 0.1, 1, 10, and 100 bit/second for corresponding copper wire diameters/ranges of 21 mm / 2000 km, 7 mm / 200 km, 2.3 mm / 20 km, and 0.7 mm / 2 km, respectively and it performs with 0.02% raw-bit error rate (99.98 % fidelity). The raw-bit security of this practical system significantly outperforms raw-bit quantum security. Current injection breaking tests show zero bit eavesdropping ability without triggering the alarm signal, therefore no multiple measurements are needed to build an error statistics to detect the eavesdropping as in quantum communication. Wire resistance based breaking tests of Bergou-Scheuer-Yariv type give an upper limit of eavesdropped raw bit ratio of 0.19 % and this limit is inversely proportional to the sixth power of cable diameter. Hao's breaking method yields zero (below measurement resolution) eavesdropping information.

physics.gen-ph↗

arXiv2011

Enhanced control of excimer laser pulse timing using tunable additive noise

Recently we have shown a system developed to precisely control the laser pulse timing of excimer lasers [1]. The electronic circuit based on an embedded microcontroller and utilized the natural jitter noise of the laser pulse generation to improve the long term regulation of the delay of the laser related to an external trigger pulse. Based on our results we have developed an improved system that uses additional, programmable time delay units to tune the noise source to further enhance performance and allows reduction of complexity in the same time. A mixed-signal microcontroller generates a randomly dithered delay of the pulse generation moment to enhance the resolution and also runs a dedicated algorithm to optimize regulation. The compact, flexible hardware supports further enhancements; the signal processing algorithm can be replaced even by in-system reprogramming. Optimized processing and the relaxed hardware requirements may also support low-power operation, wireless communication, therefore the application possibilities may be extended to many other disciplines.

physics.ins-det↗

arXiv2011

Compact USB-based Instruments for Education and Remote Laboratory Projects

Interactivity, experimenting and performing laboratory practicals contribute much to the efficiency of natural science and engineering education. Computers represent a natural element for today's students, thus the use of computers in experiments may engender considerable enthusiasm amongst them. Here we introduce two open-source, compact USB-based data acquisition devices, which we have developed for the purposes of education. These instruments offer connectivity to various sensors, like thermistors, photodiodes, sensors of acceleration, pressure, magnetic field and many other physical quantities, and provide both digital and analogue outputs.

physics.ed-ph↗

arXiv2011

Efficient Sound Card Based Experimention At Different Levels Of Natural Science Education

Sound cards, which count as standard equipment in today's computers, can be turned into measurement tools, making experimentation very efficient and cheap. The chief difficulties to overcome are the lack of proper hardware interfacing and processing software. Sound-card experimentation becomes really viable only if we demonstrate how to connect different sensors to the sound card and provide suitable open-source software to support the experiments. In our talk, we shall present a few applications of sound cards in measurements: photogates, stopwatches and an example of temperature measurement and registration. We also provide the software for these applications.

physics.ed-ph↗

arXiv2011

Compact USB measurement and analysis system for real-time fluctuation enhanced sensing

Measuring the resistance fluctuations of gas sensors provides new opportunities to enhance the selectivity and sensitivity of the sensor. Taking advantage of this possibility requires special low-noise measurement hardware and software to acquire data and perform analysis. In this paper we will present a small, USB-powered device capable of doing precise measurement of the resistance fluctuations of different kinds of gas sensors. We have developed a graphical user interface software to control the parameters of the measurement, to collect data and perform real time analysis on the measured data. The analysis is based on a PCA algorithm, which is proven to be a high performance tool to support fluctuation enhanced sensing. The system has been tested on Taguchi and carbon nanotube based gas sensors as well. The main advantages of the system include the small form factor, low cost and the fully featured software performing all required data analysis operations. Complemented with a gas sensor and an optional test chamber, the setup can serve as an efficient tool for practical fluctuation-enhanced gas sensing.

physics.ins-det↗

arXiv2007

Thermal noise informatics: Totally secure communication via a wire; Zero-power communication; and Thermal noise driven computing

Very recently, it has been shown that thermal noise and its artificial versions (Johnson-like noises) can be utilized as an information carrier with peculiar properties therefore it may be proper to call this topic Thermal Noise Informatics. Zero Power (Stealth) Communication, Thermal Noise Driven Computing, and Totally Secure Classical Communication are relevant examples. In this paper, while we will briefly describe the first and the second subjects, we shall focus on the third subject, the secure classical communication via wire. This way of secure telecommunication utilizes the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The communicator is unconditionally secure at the conceptual (circuit theoretical) level and this property is (so far) unique in communication systems based on classical physics. The communicator is superior to quantum alternatives in all known aspects, except the need of using a wire. In the idealized system, the eavesdropper can extract zero bit of information without getting uncovered. The scheme is naturally protected against the man-in-the-middle attack. The communication can take place also via currently used power lines or phone (wire) lines and it is not only a point-to-point communication like quantum channels but network-ready. Tests have been carried out on a model-line with ranges beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and security performance. This simple device has single-wire secure key generation/sharing rates of 0.1, 1, 10, and 100 bit/second for copper wires with diameters/ranges of 21 mm / 2000 km, 7 mm / 200 km, 2.3 mm / 20 km, and 0.7 mm / 2 km, respectively and it performs with 0.02% raw-bit error rate (99.98 % fidelity).

physics.gen-ph↗

arXiv2006

Totally secure classical networks with multipoint telecloning (teleportation) of classical bits through loops with Johnson-like noise

First, we show a new inexpensive defense against intruders and the man-in-the-middle attack in the Kirchhoff's-loop-Johnson-like-noise (KLJN) cipher. Then instead of point-to-point communication, we propose a high efficiency, secure network. The (in the idealistic case totally secure) classical network is based on an improved version of the KLJN cipher. The network consists of two parallel networks: i) a chain-like network of securely communicating, electrically isolated Kirchhoff-loops with Johnson-like noise and driven by a specific switching process of the resistances; ii) and a regular non-secure data network with a Coordinator-server. If the classical network is fast enough, the chain-like network of N communicators can generate and share an N bit long secret key within a single clock period of the ciphers and that implies a significant speed-up compared to the point-to-point key exchanges used by quantum communication or RSA-like key exchange methods. This is a teleportation-type multiple telecloning of the classical information bit because the information transfer can take place without the actual presence of the information bit at the intermediate points of the network. With similar quantum schemes the telecloning of classical bits via quantum communicator networks without telecloning the quantum states is also possible.

physics.gen-ph↗