Search

This Editorial introduces a Special Issue of papers from the SEE International Conference RADAR 2019, which took place in Toulon, France, 23–27 September 2019. The papers are expanded versions of ones that were judged in the reviewing process to be of the highest quality and relevance. Benefitting from the unique location of the conference centre on the French Riviera, the conference was given the theme ‘Sensing from sea to space’, attracting nearly 400 attendees from 26 countries from all over the world (Figure 1). Engineers and researchers coming from private or public sector (universities and laboratories) shared their knowledge and experience on radar topics of common interests from physics to signal processing, from sensor validation to system design, and also on emerging technologies based on artificial intelligence; all topics being supported by 200 papers presented either in oral (150 papers in 36 sessions), or poster sessions (50 papers). Figure 2 shows the range of topics of the papers. 1 FIGURE Conference attendees by country 2 FIGURE Conference paper topics

This paper presents the design, manufacturing and measurements of antennas on paper, realized using ink-jetprinting of conductive inks based on nano-silver particles (nSPs). The extraction of the substrate characteristicssuch as the dielectric constant and dielectric loss is performed using a printed ring resonator technique. Thecharacterization of the nSPs conductive inks assesses different parameters as sintering time and temperature.Two antennas are realized corresponding to the most common needs for Wireless Sensor Networks (WSN) inTrains Environment. The first one is a patch antenna characterized by a broadside radiation pattern and suitedfor operation on metallic structures. The second one is a quasi-yagi antenna, with an end fire radiation patternand higher directivity, without requiring a metallic ground plane. Both antennas present a good matching (S11 < -20 dB and S11 < -30 dB, respectively) and acceptable efficiency (55 % and 45 %, respectively) for the papersubstrate used at the center frequency of 2.4 GHz, corresponding to the first channel of the IEEE 802.15.4 band.

Two-dimensional (2D) transition metal carbides and carbonitrides, called MXenes, with metallic conductivity and hydrophilic surfaces, show great promise as electrode materials for supercapacitors. ...

SUMMARY Digital books have become popular as electronic media has become more common. An evaluation that includes not only a subjective assessment of readability or usability, but also an objective assessment of psychometric health impact is needed. The goal of this study is an objective assessment of the physiological and psychological effects of reading books using electronic or paper media. This paper focuses on hemodynamic parameters. The measurement items include VAS and POMS as a psychological index and hemodynamic parameters as a physiological index. As a result, low levels of vigor and limited readability were recognized as significant (p < 0.05) when reading a book using electronic media as compared to paper media. The cardiovascular system was actively engaged in coping because of sympathetic hyperactivity in the hemodynamic reaction. By contrast, using electronic media was not seen to involve stress coping. We also found that the parasympathetic nervous system activity was enhanced by the illegibility of sentences and fatigue due to using electronic media. Based on all of these results, we identified a difference in how people react physiologically when reading a book using electronic and paper media.

One of the most interesting and important problems, met during the development of non-pressurized impregnated paper cables for high voltage direct current, arose from the introduction of a long-duration type test at thermal cycles under a DC steady voltage of twice the working voltage. DC cables manufactured according to a traditional paper insulating technique showed during the cooling phase of a thermal cycle a catastrophic fall of the dielectric strength of the order of 50 %. The reason for this fall is analysed both theoretically and experimentally and the way to overcome the obstacle is explained and discussed.

SUMMARY In the late years, personal information must be protected at the agency in the field of insurance. We develop an agency contract system that protects personal information of the contractor and information to confirm intention to contract by background texture watermarks. When the contractor carries an application form, it may be folded, rumpled, or waved little. In this case, contractor's information must be recognized from background watermarks printed on the application form. But it cannot be recognized surely folded, rumpled, or waved application form by the conventional method. In this paper, we propose a new recognition of watermark dot information from folded, rumpled, or waved application form. The new recognition is composed of crooked point sequence recognition expressing character borders by searching around calculated point, and dot recognition by shading folded, rumpled, or waved paper and emphasizing dot in luminosity from this paper. As a result, we got correct recognition ratio of more than 99% from folded, rumpled, or waved paper.

This paper describes the dielectric breakdown characteristics of oil and oil-impregnated paper for very fast transient (VFT) voltages. Blumlein circuits generate VFT voltages of 60 and 300 ns in a pulse width that simulates disconnecting switching surges in gas-insulated switch gears. We measured the breakdown voltages of needle-to-plane, plane-to-plane oil gaps and several pieces of paper between plane electrodes for VFT and lightning impulse voltages. The measured data were formulated in V-t characteristics and Weibull probability distributions. The inclination n of V-t characteristics of insulating paper is 150, which is less than n = 13.7 of the plane-to-plane oil gap in the VFT time range. The shape parameters of Weibull distribution obtained in this study show that the scattering of breakdown voltages of paper is much less than that of oil. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 16–24, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10043

Power capacitors are highly reliable due to their completely enclosed configuration. They are relatively trouble-free over the long term. However, their dielectric strength can be reduced due to some stresses, including overvoltage application or thermal degradation of the insulation material during long periods of operation; these events can result in dielectric breakdown of capacitors in extreme cases. Since almost all power capacitors with oil-impregnated paper have been operated for more than twenty years, some kind of failure should be expected. To prevent these incipient accidents, it is important to examine the insulation deterioration mechanism and evaluate the degree of deterioration before capacitor breakdown. To establish a diagnostic method of deterioration of the capacitors with oil-impregnated paper, we have conducted thermally and electrically accelerated deterioration tests and investigated the changes of their characteristics. Based on the experimental results we obtained, it can be concluded that the behavior of the oil-dissolved gases can be used as a useful index to diagnose the insulation deterioration of these capacitors.

A sudden capacity increase in demand during the summer peak, or in contingencies such as malfunctioning transformers, may cause an overload in normal transformers. In this paper, on the basis of overloaded transformer operation in distribution substations, thermal aging testing in oil was carried out under various overload patterns, such as short-term overload and long-term overload, but with the winding insulation paper's lifespan loss kept constant. From the results, various characteristics, such as the mean degree of polymerization and production of furfural and (CO2 +CO), and their effects on the lifespan loss of the insulation paper, were obtained. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(2): 1–8, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21292

This letter presents a high-voltage power amplifier for driving flexible paper speaker. Simple circuit complexity and high signal quality can be achieved. The operating principles and design considerations of the studied paper speaker power amplifier are analyzed and discussed. A laboratory prototype is built and tested. The experimental results are shown to verify the studied scheme. Copyright © 2012 John Wiley & Sons, Ltd.

The letter presents the design, fabrication, and measurement of a configurable radio frequency identification (RFID) tag based on time-domain reflections. The tag circuit contains a microstrip line (ML) that propagates radio frequency (RF) signals, and a group of capacitors that introduce impedance discontinuities to encode binary codes. The configurability of the tag circuit is allowed by connecting the nearby-placed capacitors with the ML. Ink-jet printing technology is employed to implement the layout of the proposed tag on paper substrate. To overcome the limitations of printed metallic tracks, a linearly tapering technique is proposed. With this technique, a four-bit configurable passive chipless RFID tag is realized. Both time-domain reflectometry (TDR) measurements and ultrawideband (UWB) characterizations were conducted for the proposed tag, and the results are in good consistence with the simulation ones from the circuit simulator advanced design system (ADS). Owing to its low cost fabrication and environmentally friendly nature, the proposed tag has great potential to be widely employed in low-end RFID applications. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53: 2781-2786, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26412

This paper discusses a λ/4-type wave absorber for the microwave band made with conductive paper, which is paper with a coating of conductive material. A simplified wave absorber of this type is first designed and constructed for the X band and Ku band. Using the resulting absorption characteristics, experimental formulas are derived for the relative permittivity and surface resistance. These formulas are then used to design and construct a more practical wave absorber, whose absorption characteristics are measured. Excellent absorption characteristics, better than 20 dB, are verified in the intervals from 8.2 to 10.6 GHz and from 14.1 to 17.2 GHz for wave absorption in the X band and Ku band, respectively, although there is a difference of approximately 0.4 dB between the designed matching frequency and the measured value. Design guidelines for such a microwave absorber using a conductive coating are then presented. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(10): 100–107, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1180

The bushing of a transformer is one part of the transformer system, but is as vital as the transformer itself because it forms a part of the main circuit. Deterioration and abnormal condition of the bushing possibly cause its destruction, shortage of the main circuit to the Earth, and fire in the systems, so that diagnosis of the bushings is thus very important. At present, mainly visual inspection from outside of the bushing is carried out. Inspection of the inside condition of the bushing by dissolved gas analysis of the inside oil is done only as sampling for selected bushings because it is difficult due to the sealed construction of the bushings. Therefore, a simple diagnostic method for bushings has been expected for a long time. In Eastern Europe, the RVM (Return Voltage Measurement) method based on scanning the polarization spectra was applied to the oil–paper insulation systems inside the transformer as a diagnostic method. In this paper we investigate theoretically the principle of the RVM method applied to bushings with the same oil–paper insulation systems as the transformer by using the equivalent circuit, and the possibility of using this novel diagnostic method for condenser-type bushings is demonstrated by a model experiment. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 21–29, 2000

Today's advanced high-speed technology requires building behavioral models of systems, from measured/simulated data, with increasingly higher operating frequencies. Different research efforts have come to light in literature for macromodeling, based on such types of data. Ensuring passivity is one of the most fundamental issues affecting system macromodeling, because system-level performance can be unstable if even a single component of the system becomes nonpassive. Thus, from the computer-aided design perspective, generation and provision of macromodels, while preserving passivity, is a significant challenge. In this paper, we carefully review novel techniques of passive macromodeling as well as their passivity verification and enforcement, from the early days to the present. We critically review the prominent methods in literature developed for macromodeling, and for verification and enforcement of passivity, and emphasize on their strengths and shortcomings.

A compact dual-WLAN-band antenna, in the shape of a paper clip, is presented. The antenna can be easily manufactured by bending few times a single copper wire with a length of about 65 mm, and it operates in the 2.4 and 5.2 GHz bands in the WLAN environment. In addition to the simple configuration, the antenna is easily fed by a 50-Ω mini-coaxial cable which allows it to be flexible in a defined location for installation. An experimental prototype of the proposed antenna with the overall dimensions of about 5 mm × 23.5 mm is constructed, tested, and demonstrated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2572–2574, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23760

Applications of HTS to radiating elements and beam-forming networks of multibeam and/or multifrequency arrays are discussed. This includes radiating elements which meet special requirements with respect to size and frequency response. Realized versions of both a three-port HTS array and a April × 4 Butler matrix are presented. © 1993 John Wiley & Sons, Inc.

This note is a corrigendum of the paper ‘Linear Time Varying Model Predictive Control and its Application to Active Steering Systems: Stability Analysis and Experimental Validation’, published on the volume 18, issue 8, pages 862–875 of the International Journal of Robust and Nonlinear Control in 2008. Next we point out a technical error in the proof of Lemma 2 of the paper, and provide the corrected version of the lemma. Copyright © 2011 John Wiley & Sons, Ltd.