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1
Katulski e Namiotko. "Topological Model of an Electromagnetic Environment Inside a Ship for Electromagnetic Compatibility (EMC) Analysis". Applied Sciences 9, n. 20 (12 ottobre 2019): 4293. http://dx.doi.org/10.3390/app9204293.
Testo completoAbstract (sommario):
The mutual electromagnetic (EM) interactions between electrical and electronic devices in a segmented space, such as a ship’s environment, are described. Knowledge of EM interference signal (EM disturbance) distribution is important when setting correct locations for electrical and electronic equipment in a ship’s environment. Firstly, the topological structure of a ship’s segmented internal environment (under the main deck), which consists of many electrical screening walls (shielding planes), is presented. The planes attenuate the EM disturbances. Then, taking into account the ship’s topological structure, a general description of the EM disturbance distribution, called the ship’s topological electromagnetic compatibility (EMC) model, is formulated using matrix expressions. This model includes EM disturbances that radiate from a ship’s own internal sources (located under the main deck) and/or external sources (located above the main deck), and/or that radiate from extraneous external sources, i.e., from other ships and/or aircrafts. A description of the model for an example EMC ship scenario and a partial verification of its measurements are shown and discussed. Finally, a discussion of the usefulness of the proposed model in an analysis of a ship’s EMC conditions concludes this study.
2
Karami, Hamidreza, Marcos Rubinstein, Farhad Rachidi, Christophe Perrenoud, Emmanuel de Raemy, Pascal Kraehenbuehl e Arturo Mediano. "EMC Impact of Disturbances Generated by Multiple Sources". Electronics 11, n. 21 (29 ottobre 2022): 3530. http://dx.doi.org/10.3390/electronics11213530.
Testo completoAbstract (sommario):
In this paper, the impact of an increasing number of arbitrary electrical/electronic devices on the overall radiated emissions is investigated. Understanding and quantifying such an impact are prerequisites to the proper evaluation of electromagnetic compatibility (EMC) of various electronic systems and devices and, if needed, to revisiting the international standards. To evaluate the radiated emissions from multiple electronic devices, each arbitrary electronic device is characterized using an equivalent Huygens’s surface, in which the tangential components of electric and magnetic near fields are calculated (or measured). The radiated emission from the arbitrary electronic device can be calculated using the electric and magnetic near fields for an arbitrary phase (correlated or uncorrelated), position, and orientation. The influence of several parameters affecting the radiated emissions from multiple arbitrary electronic devices, including the number of disturbance sources, the polarization of each device, the radiation pattern of each device, the location and orientation of each device, and the phase shifts between devices, are analyzed. The numerical results show that the mentioned parameters have a significant effect on the radiated emissions, and cannot be neglected in EMC considerations. In general, increasing the number of electronic devices leads to an increase in the level of radiated emissions. However, the increase depends on other parameters such as the arrangement (the radiation pattern for each device, the distance between the devices, and the orientation and/or polarization of each device). The proposed method can be straightforwardly applied to devices characterized by near-field measurements or multimodular large equipment with long cables.
3
Brodecki, Dariusz, Ernest Stano, Mateusz Andrychowicz e Piotr Kaczmarek. "EMC of Wideband Power Sources". Energies 14, n. 5 (7 marzo 2021): 1457. http://dx.doi.org/10.3390/en14051457.
Testo completoAbstract (sommario):
In this paper the results of the EMC tests of the wideband power sources: the PWM-based power source and audio power amplifier are discussed. They are intended to be used to supply the measuring system developed for evaluation of the wideband transformation accuracy of instrument transformers. Therefore, it is required to detect possible interferences that may be caused by the power supply to its operation and that may cause a decrease in its accuracy. The tests concern the conducted emission in the frequencies range from 150 kHz to 30 MHz and the radiated emission in the frequencies range from 30 MHz to 1 GHz. Moreover, the level of conducted disturbances in frequencies range from 100 Hz to 5 kHz generated into the supplying current is measured and the immunity of both wideband power sources to low frequency conductive disturbances in the supplying voltage and current is tested. Then, the voltage gain error and phase shift of the output voltage are measured. The EMC tests of both power sources show lack of compliance with the requirement of the standard IEC 61326-1. However, in system application of the audio power amplifier is possible if required increased immunity to conducted emission of the measuring system is ensured.
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Mazurek, Paweł. "Chosen Aspects of the Electromagnetic Compatibility of Plasma Reactors with Gliding Arc Discharges". Applied Sciences 10, n. 11 (29 maggio 2020): 3789. http://dx.doi.org/10.3390/app10113789.
Testo completoAbstract (sommario):
This paper presents an analysis of electromagnetic disturbance interactions inside the three-phase gliding arc plasma generation installation. This is the main part of the electromagnetic compatibility analysis of the reactor installation. All elements of the nonthermal plasma installation are described from the point of view of disturbance generation and their influence on the power supply system. The analysis is based on the results of tests carried out in accordance with the guidelines of the electromagnetic compatibility (EMC) Directive and harmonised standards. The disturbances measured are large, over 20 dB above the limits. The disturbances measured allow valid conclusions to be reached in relation to this type of installation. The implication is the need for plasma reactors designed with elements that reduce radiated and conducted interference.
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Hubacz, Marcin, Dariusz Klepacki, Kazimierz Kuryło, Bartosz Pawłowicz, Wiesław Sabat e Bartosz Trybus. "Analysis of Electromagnetic Disturbances Generated by an Autonomous RFID-Based Navigation Robot". Periodica Polytechnica Electrical Engineering and Computer Science 63, n. 2 (19 marzo 2019): 112–21. http://dx.doi.org/10.3311/ppee.13461.
Testo completoAbstract (sommario):
The paper discusses the issue of EMC compatibility of autonomous navigation robots that utilize the RFID technology for surface discovery. The robots can work individually or in a group in environments equipped with RFID transponders. The need to examine EMC compatibility of such robots is pointed out, so that they can work and communicate without disturbing other devices or each other. Measurements and analysis of electromagnetic disturbances generated by a prototype of a navigation mobile robot has been carried out. Results of the measurements for the model of the robot are presented. Factors determining generation of the disturbances in the model are pointed out.
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Asmanis, Gundars, Leonids Ribickis e Vladimirs Novikovs. "Troubleshooting of Matrix Frequency Converter Conducted and Radiated Emissions". Scientific Journal of Riga Technical University. Power and Electrical Engineering 27, n. 1 (1 gennaio 2010): 146–51. http://dx.doi.org/10.2478/v10144-010-0038-7.
Testo completoAbstract (sommario):
Troubleshooting of Matrix Frequency Converter Conducted and Radiated EmissionsMatrix converter inherently exhibits sinusoidal input current waveforms and has less stressful output voltage waveforms, but it is causing problems with conducted and radiated emissions. This paper deals with matrix converter emitted disturbances from point of view of electromagnetic compatibility (EMC) standard EN61800-3 and allocates the sources of undesirable emissions using standard equipment used for EMC assessment according to variety international EMC standards and discusses methodology of troubleshooting flow, using low cost equipment available in almost every laboratory of Industrial Electronics and Electrical Engineering.
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Grganić, Hrvoje, Marko Valjak, Gregor Škorc e Luka Romac. "Ensuring Electromagnetic Compatibility in Nuclear Power Plant beyond Equipment Qualification Tests". Journal of Energy - Energija 68, n. 2-3 (8 luglio 2022): 43–50. http://dx.doi.org/10.37798/2019682-3190.
Testo completoAbstract (sommario):
Electromagnetic compatibility (EMC) is defined as the capability of equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that same environment [1]. EMC regulatory requirements for instrumentation and control (I&C) equipment were not developed or in effect until the last few years. Therefore, there is a considerable number of plant equipment that has not been qualified for EMC. The current EMC regulatory requirements address new and modified equipment only, and do not call for testing of existing equipment. There is a gap, which has to be overcome, in order to understand the current level of EMC within the plant. Equipment qualification normally implies formal tests in EMC chambers, which is not practical for the equipment already installed. This paper is a short overview of the preparation phase of a project that includes various EMC-related activities currently being performed in Krško nuclear power plant (NPP). The activities are categorized into two main groups: equipment immunity (susceptibility) tests, used as an assessment of the immunity of the existing equipment such as process cabinets, transmitters and similar, and zone mapping measurements, which are performed to record the electromagnetic environment of the selected plant areas. There is no clear, detailed and unambiguous guidance on how to perform any of these tests. It takes a lot of engineering judgement to optimize them for a specific plant. Some of the most important questions addressed in this paper are 1) the selection of the plant areas for zone mapping measurements and susceptible equipment to be tested for immunity, 2) choice of electromagnetic disturbances, which shall be simulated during those tests, and 3) practical performance, i.e. harmonization of immunity tests with operation of other plant systems. It is necessary to decide which operation mode poses the “worst-case”, i.e. how and when the immunity tests and zone mapping measurement should be performed. The paper also addresses troubleshooting of poor EMC design and installation practices, which can significantly reduce the number of EMC-related problems in a plant.
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Chand, B., T. Kut e S. Dickmann. "Optimal design of active EMC filters". Advances in Radio Science 11 (4 luglio 2013): 243–49. http://dx.doi.org/10.5194/ars-11-243-2013.
Testo completoAbstract (sommario):
Abstract. A recent trend in automotive industry is adding electrical drive systems to conventional drives. The electrification allows an expansion of energy sources and provides great opportunities for environmental friendly mobility. The electrical powertrain and its components can also cause disturbances which couple into nearby electronic control units and communication cables. Therefore the communication can be degraded or even permanently disrupted. To minimize these interferences, different approaches are possible. One possibility is to use EMC filters. However, the diversity of filters is very large and the determination of an appropriate filter for each application is time-consuming. Therefore, the filter design is determined by using a simulation tool including an effective optimization algorithm. This method leads to improvements in terms of weight, volume and cost.
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Ivo Uglešić, Miroslav Křepela e Viktor Milardić. "Solving EMC problems in the design of new HV test laboratory". Journal of Energy - Energija 59, n. 1-4 (22 agosto 2022): 77–82. http://dx.doi.org/10.37798/2010591-4281.
Testo completoAbstract (sommario):
The paper deals with solving electromagnetic compatibility (EMC) problems in the design of a new, case study, industrial high voltage test laboratory, intended to be used for testing of transformers and other apparatus up to 550 kV rated voltage. Modern high voltage test facilities are equipped, apart from primary test devices like AC, DC and impulse voltage generators etc., also with sophisticated numerical measuring instruments and informatics technology. Since such devices are sensitive to transient overvoltages, the highest degree of EMC is to be secured. This can be achieved by proper earthing and screening of test laboratory, what shall be designed in a way to satisfy all requirements conditioned by building lightning protection, personal protection and system earthing, avoiding electromagnetic compatibility disturbances at the same time. One of the main tasks is solving electromagnetic compatibility problems caused by outdoor electromagnetic disturbances originating from various unknown sources. Those disturbances and interferences may seriously influence measuring accuracy and readings of test devices, what consequently leads to false results. The stated is especially relating to partial discharge measurements. As to avoid such disturbances, the laboratory shall be completely screened with a net forming optimally designed Faraday cage. On the other hand, at high voltage tests with impulse voltages, especially with chopped tail waves, steep transient overvoltages may be generated. As a consequence, high transient potential differences between particular points along the earth electrode may occur, what can even lead to flashovers between parts of it. Therefore is of utmost importance to provide proper earthing and low inductance current return path for impulse high voltage test equipment where high frequency transients are to be anticipated. Improper earthing and bonding may result, apart from mentioned flashovers, in severe induced voltages in secondary cables with consequential influence on test results, possible destruction of measuring instruments and hazardous touch voltages for personnel. For analyzing transient potential differences, it is important to model, with maximum accuracy, impulse test circuit (impulse generator, chopping spark gap, voltage divider, Faraday cage, fundament earth electrode, earthing strips, earthing rods etc.). Magnitude of transient potential difference between particular points is proportional to earth electrode inductance, i.e. low inductance of earth electrode will result in decrease of transient potential difference.
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GHALEM, Sara, Abdelber BENDAOUD, Houcine MILOUDI, Mohamed Hamza BERMAKI, Mohamed MILOUDI e Abdelhakim ZEGHOUDI. "Prediction of Conducted Disturbances Generated by a DC/DC Converter". Eurasia Proceedings of Science Technology Engineering and Mathematics 26 (30 dicembre 2023): 507–18. http://dx.doi.org/10.55549/epstem.1411082.
Testo completoAbstract (sommario):
This paper introduces a detailed approach to model and simulate conducted electromagnetic interference (EMI) in the time domain using Lt-Spice software. The focus of the study is on the Buck converter, with the aim of identifying and characterizing electromagnetic disturbance sources arising from the power supply. The research also seeks to analyze their propagation paths and examine the impact of switch selection and control parameters on the electromagnetic compatibility (EMC) signature of the converter. The proposed methodology employs a comprehensive modeling strategy that accounts for the interactions between various converter components and their associated parasitic elements. By accurately representing the electrical and magnetic fields in the time domain, the simulation captures the dynamic behavior of the system, allowing for a realistic assessment of conducted disturbances. The research begins with a thorough examination of the power supply and its switching behavior. Key device characteristics, including switching frequency, voltage, and current waveforms, are carefully analyzed to understand their influence on conducted EMI. Additionally, the model integrates parasitic elements linked to the power device, such as inductive and capacitive components, to address their impact on electromagnetic emissions. Furthermore, the study delves into the propagation paths of conducted disturbances, considering the parasitic elements of the converter's layout, such as PCB traces, cables, and connectors. It evaluates the effects of these elements on electromagnetic emissions, providing insights into propagation mechanisms and potential coupling paths. Various switch types, such as MOSFET or IGBT, are examined, and their effects on conducted EMI are evaluated. Through comprehensive simulations and analysis, the paper offers valuable insights into the conducted disturbances generated by the DC/DC converter, contributing to a comprehensive understanding of the system's electromagnetic behavior. The findings presented in this study can inform the design and optimization of DC/DC converters, facilitating the development of more EMC-friendly solutions.
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Zych, Piotr, Radosław Roszczyk, Jan Sroka e Ken Kawamata. "The Phenomena of Bursts by Opening Low-Voltage Relay". Energies 15, n. 17 (24 agosto 2022): 6155. http://dx.doi.org/10.3390/en15176155.
Testo completoAbstract (sommario):
The article deals with the issue of electromagnetic disturbances caused by electromechanical relays. Electromagnetic compatibility (EMC) is important for the reliable work of electrical and electronic devices. Our research focused on the low-voltage relay, which is the source of electrical fast transients (EFT)/burst disturbances. The voltage and current waveforms were tested on the constructed stand while opening the relays’ contacts. We investigated one-circuit topology with varied element parameters in order to observe their influence on the burst phenomenon. The new technologies in the measurement equipment allow us to observe many detailed aspects of the burst phenomenon, which were not reported up to now. In order to analyze the disturbances, they have been fragmented into restoration, ignition and arc times. The number of disturbance cycles differs depending on the value of the circuit capacitance on the load side. The effect of capacity on times of restoration, ignition and burning arc was also observed. The division into cycles allowed us to observe changes in the studied phenomenon along with the increased distance between the relay contacts during its opening. There were also discrepancies between the presentation of the phenomenon in the standard defining the method of measuring the resistance to interference EFT/burst and the measurement results.
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Baghdadi, Benazza, Bendaoud Abdelber, Reineix Alain, Dafif Omar e Slimani Helima. "Experimental study of the behaviour of the crosstalk of shielded or untwisted-pair cables in high frequency". Serbian Journal of Electrical Engineering 16, n. 3 (2019): 311–24. http://dx.doi.org/10.2298/sjee1903311b.
Testo completoAbstract (sommario):
Electromagnetic disturbances from natural phenomena such as lightning, or those generated from industrial activity, can cause harmful interference in onboard electronic systems. The disturbances are generally transformed into radiated and conducted disturbances, using wired connections to spread their effects in electrical and electronic systems. In order to identify the paths of propagation and coupling of these HF currents into a complete system and propose solutions to reduce EMC interference, it is necessary and important to carry out experimental case studies on the coupling between shielded as well as unarmoured cables, in order to identify the importance of differential and common-mode currents. Measurements were made using a 4-way vector network analyser giving the results of the crosstalk between victim and culprit cables as well as for module and phase.
13
González-Ramos, Jon, Itziar Angulo, Igor Fernández, Amaia Arrinda e David de la Vega. "Characterization of the Potential Effects of EMC Filters for Power Converters on Narrowband Power Line Communications". Electronics 10, n. 2 (12 gennaio 2021): 152. http://dx.doi.org/10.3390/electronics10020152.
Testo completoAbstract (sommario):
Electromagnetic Compatibility (EMC) filters are one of the main solutions for dealing with the disturbances generated by power inverters. However, they show series/parallel resonances that introduce variations in the impedance seen from the grid. Consequently, in some cases, these filters have low impedances at resonance frequencies, which can affect Narrowband Power Line Communications (NB-PLC) due to notching effects. For that reason, the potential effects of four EMC filters on NB-PLC have been studied. Laboratory trials in a controlled environment have been carried out, in which the attenuation and the Signal-to-Noise Ratio (SNR) thresholds that define the communication’s quality have been studied. The results presented in this paper show that, although the variations of the channel frequency response are not selective enough to degrade the communication thresholds, the attenuation measured when the filter is connected near the receiver might be sufficiently high to be critical for the communications in some situations. Therefore, EMC filters might have a negative impact on NB-PLC that had not been previously considered.
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Razek, Adel. "Assessment of a Functional Electromagnetic Compatibility Analysis of Near-Body Medical Devices Subject to Electromagnetic Field Perturbation". Electronics 12, n. 23 (25 novembre 2023): 4780. http://dx.doi.org/10.3390/electronics12234780.
Testo completoAbstract (sommario):
This article aims to assess, discuss and analyze the disturbances caused by electromagnetic field (EMF) noise of medical devices used near living tissues, as well as the corresponding functional control via the electromagnetic compatibility (EMC) of these devices. These are minimally invasive and non-ionizing devices allowing various healthcare actions involving monitoring, assistance, diagnoses and image-guided medical interventions. Following an introduction of the main items of the paper, the different imaging methodologies are conferred, accounting for their nature, functioning, employment condition and patient comfort and safety. Then the magnetic resonance imaging (MRI) components and their fields, the consequential MRI-compatibility concept and possible image artifacts are detailed and analyzed. Next, the MRI-assisted robotic treatments, the possible robotic external matter introductions in the MRI scaffold, the features of MRI-compatible materials and the conformity control of such compatibility are analyzed and conferred. Afterward, the embedded, wearable and detachable medical devices, their EMF perturbation control and their necessary protection via shielding technologies are presented and analyzed. Then, the EMC control procedure, the EMF governing equations and the body numerical virtual models are conferred and reviewed. A qualitative methodology, case study and simple example illustrating the mentioned methodology are presented. The last section of the paper discusses potential details and expansions of the different notions conferred in the paper, in the perspective of monitoring the disturbances due to EMF noise of medical devices working near living tissues. This contribution highlights the possibility of the proper functioning of medical instruments working close to the patient’s body tissues and their protection by monitoring possible disturbances. Thanks to these commitments, various health recommendations have been taken into account. This concerns piezoelectric actuated robotics, assisted with MRI and the possible use of conductive materials in this imager under certain conditions. The safe use of onboard devices with EMF-insensitive or intelligently shielded materials with short exposure intervals is also of concern. Additionally, the need to monitor body temperature in case of prolonged exposure of onboard devices to EMF is analyzed in the Discussion section. Moreover, the use of virtual tissue models in EMC testing to achieve more realistic evaluation capabilities also features in the Discussion section.
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Furman, Juliusz, e Andrzej Białoń. "Influence of Commutational Interferences on the Analysis of Harmonics in the Traction Current". Problemy Kolejnictwa - Railway Reports 64, n. 187 (giugno 2020): 87–97. http://dx.doi.org/10.36137/183e.
Testo completoAbstract (sommario):
Commutation phenomena related to the processes of changing the amount of power taken or returned by a vehicle affect the frequency spectrum contained within the traction current. The paper presents the influence of selected physical phenomena on the parameters taken for FFT analysis utilized for assessment of the disturbances generated into the traction network. The paper also describes the stands used for measuring disturbances generated into the traction network. The results of the measurements and calculations of the frequency response of simulated signals are presented, as well as signals measured in real conditions during traction vehicle tests, which are useful for assessing the influence of commutational interferences on the analysis of harmonics in the traction current. Keywords: interferences, EMC, traction, interoperability
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Sun, Ji Ping, Hui Chen e Zi Jian Tian. "Radiation Disturbance from AC Motors in Underground Coal Mines". Applied Mechanics and Materials 490-491 (gennaio 2014): 1105–9. http://dx.doi.org/10.4028/www.scientific.net/amm.490-491.1105.
Testo completoAbstract (sommario):
The radiated electromagnetic disturbances produced by operating electromotor equipments in coal mines have some effects on the electromagnetic environment in coal mines. Based on the analysis of the Chinese national EMC standard on rotating electrical machines and the operation characteristics of the electromotor equipments in coal mines, it can be concluded that frequency spectrum of the radiated disturbances resulting from AC motors ranges from 9kHz to 1GHz. The radiated electromagnetic disturbances in the pumping house underground mines have been measured. The results show that the radiated emissions above 30MHz produced by the normal running electromotor system are quite low, which are comparable to the radiated emission limits set in the Chinese national standard GB 755-2008;the maximum radiated field strength reaches about 0.56V/m under 30MHz. However, when motors start or stop, the radiated field strength can reach about 1.26V/m or higher. Therefore, some shielding measures for monitoring and communication equipments should be taken to reduce the radiation interference from AC motors.
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Jaekel, Bernd, e Darren Carpenter. "Probabilistic approach for deriving immunity levels against electromagnetic disturbances". Facta universitatis - series: Electronics and Energetics 23, n. 1 (2010): 45–53. http://dx.doi.org/10.2298/fuee1001045j.
Testo completoAbstract (sommario):
Knowledge of electromagnetic environments existing at locations where equipment is intended to be operated is an essential prerequisite for achievement of electromagnetic compatibility. The necessity of such a knowledge results from the fact that suitable immunity requirements can be concluded from corresponding data regarding the electromagnetic environment. This information should include the type as well as the characteristics of electromagnetic phenomena occurring at those locations. Appropriate information can be obtained by various approaches, such as site surveys or technical assessments accompanied by evaluations of technical literature. It is obvious that the description of a general electromagnetic environment should consider a multitude of phenomena having a broad spectrum of parameters. However, in many cases such a general description is not helpful because it would imply that immunity against all such phenomena has to be taken into consideration. A more practical approach consists in introducing a classification scheme which gives a correlation between locations and the electromagnetic phenomena existing there. This concept forms the basis of the EMC publication IEC 61000-2-5. Because of continuous change of existing technologies and introduction of new ones, electromagnetic environments in a certain respect change fundamentally. This is very obvious in case of all the recently introduced radio and communication services with the generation of electromagnetic fields in the frequency range above 1 GHz. Hence the need arises to monitor continuously the electromagnetic environment and to adapt its description. Such adaptation is currently being done by a working group of IEC TC 77. The results of its work is object of the next edition of IEC 61000-2-5. The present status as well as expected changes are discussed in this paper. .
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Matsushima, Sayaka, Tohlu Matsushima, Takashi Hisakado e Osami Wada. "Trends of EMC standards for automotive network devices and communication quality of ethernet in relation to parameters of pulse disturbances". IEEE Electromagnetic Compatibility Magazine 7, n. 1 (2018): 46–50. http://dx.doi.org/10.1109/memc.0.8339542.
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Kotny, J. L., T. Duquesne e N. Idir. "Influence of the common mode impedance paths on the design of the EMI filters used with SiC-buck converter". Advanced Electromagnetics 4, n. 2 (9 dicembre 2015): 44. http://dx.doi.org/10.7716/aem.v4i2.281.
Testo completoAbstract (sommario):
This paper deals the design of EMI filter associated with buck converter using fast semiconductors silicon carbide SiC (diode and transistor JFET). To comply with EMC standards, a filter design method based on an equivalent electrical circuit is proposed. The aim is to identify the different values of the EMI filter elements but also to obtain the limits values of the parasitic elements of the passive components which have a major influence on the attenuation of the filters. The purpose is to study the influence of the modification of the common mode propagation paths before and after the installation of the filter. A solution is also proposed to reduce the conducted disturbances that occur at high frequency caused by the fast SiC components.The comparison of the simulation results with the measurements data carried out on a DC-DC converter without and with the EMI filter, shows the effectiveness of the proposed design approach.
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Suarez, Adrian, Jorge Victoria, Jose Torres, Pedro A. Martinez, Antonio Alcarria, Joaquin Perez, Raimundo Garcia-Olcina, Jesus Soret, Steffen Muetsch e Alexander Gerfer. "Performance Study of Split Ferrite Cores Designed for EMI Suppression on Cables". Electronics 9, n. 12 (24 novembre 2020): 1992. http://dx.doi.org/10.3390/electronics9121992.
Testo completoAbstract (sommario):
The ideal procedure to start designing an electronic device is to consider the electromagnetic compatibility (EMC) from the beginning. Even so, EMC problems can appear afterward, especially when the designed system is interconnected with external devices. Thereby, electromagnetic interferences (EMIs) could be transmitted to our device from power cables that interconnect it with an external power source or are connected to another system to establish wired communication. The application of an EMI suppressor such as a sleeve core that encircles the cables is a widely used technique to attenuate EM disturbances. This contribution is focused on the characterization of a variation of this cable filtering solution based on openable core clamp or snap ferrites. This component is manufactured by two split parts pressed together by a snap-on mechanism which turns this into a quick, easy to install solution for reducing post-cable assembly EMI problems. The performance of three different materials, including two polycrystalline (MnZn and NiZn) materials and nanocrystalline (NC) solution, are analyzed in terms of effectiveness when the solid sleeve cores are split. The possibility of splitting an NC core implies an innovative technique due to the brittleness of this material. Thus, the results obtained from this research make it possible to evaluate this sample’s effectiveness compared to the polycrystalline ones. This characterization is carried out by the introduction of different gaps between the different split-cores and analyzing their behavior in terms of relative permeability and impedance. The results obtained experimentally are corroborated with the results obtained by a finite element method (FEM) simulation model with the aim of determining the performance of each material when it is used as an openable core clamp.
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Borecki, Michał, e Jan Sroka. "Diversity Pertaining to the Attenuation of the RF Disturbance Suppression Power Line Filters". Electronics 12, n. 4 (6 febbraio 2023): 821. http://dx.doi.org/10.3390/electronics12040821.
Testo completoAbstract (sommario):
Filters for the suppression of the RF disturbances in power lines are passive; wideband stop filters attenuating common as well as differential disturbances should be insensitive to the variation in the impedance at the input and the output. The design and verification process of such filters differs entirely from that used for the signal RF filters. In the document CISPR 17, entitled “Methods of measurement of the suppression characteristics of passive EMC filtering devices”, two definitions of the attenuation of the common and differential modes are presented. The first is simply direct measurement, and the second is based on a calculation using the single-ended S-parameters of the multiport. These two definitions are the source of diversity. In this paper, we hypothesize that the attenuations achieved with these two methods are identical only if the filter is in perfect balance. Consequently, different attenuations can be achieved. The requirement of balance can be violated due to the tolerances of the components used in the filter. The paper begins with a simple unbalanced four-port, for which analytical formulas are derived. It is also shown that an approach with single-ended S-parameters enables the calculation of the mode conversion between the input and the output, which is called the conversion loss. This is the measure of the grade of the imbalance. Thereafter, the common-mode attenuation of an exemplary RF suppression filter is derived with the presented methods. Additionally, the conversion loss of the filter is calculated. The comparison of the conversion loss with both attenuations is satisfactory, proving the hypothesis formulated in the paper.
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Phukapak, Sorawin, Daisuke Koyama, Kotaro Hashikura, Md Kama, Iwanori Murakami e Kou Yamada. "Parameterization of All Disturbance Observers for Periodic Input Disturbances". ECTI Transactions on Electrical Engineering, Electronics, and Communications 21, n. 2 (27 giugno 2023): 249809. http://dx.doi.org/10.37936/ecti-eec.2023212.249809.
Testo completoAbstract (sommario):
In this paper, we examine the parameterizations of all disturbance observers and all linear functional disturbance observers for periodic input disturbances. The plant disturbance observers have been used to estimate the disturbance in the plant. Several papers on design methods for disturbance observers have been published. Recently, the parameterization of all dis- turbance observers and all linear functional disturbance observers for plants with any input disturbance was clarified. However, no paper examines the parameteriza- tion of all disturbance observers or all linear functional disturbances for periodic input disturbances. In this paper, we propose parameterizations of all disturbance observers and all linear functional disturbance observers for periodic input disturbances.
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Keghie, J., R. Kanyou Nana, B. Schetelig, S. Potthast e S. Dickmann. "Estimation of the interference coupling into cables within electrically large multiroom structures". Advances in Radio Science 8 (1 ottobre 2010): 175–78. http://dx.doi.org/10.5194/ars-8-175-2010.
Testo completoAbstract (sommario):
Abstract. Communication cables are used to transfer data between components of a system. As a part of the EMC analysis of complex systems, it is necessary to determine which level of interference can be expected at the input of connected devices due to the coupling into the irradiated cable. For electrically large systems consisting of several rooms with cables connecting components located in different rooms, an estimation of the coupled disturbances inside cables using commercial field computation software is often not feasible without several restrictions. In many cases, this is related to the non-availability of computing memory and processing power needed for the computation. In this paper, we are going to show that, starting from a topological analysis of the entire system, weak coupling paths within the system can be can be identified. By neglecting these coupling paths and using the transmission line approach, the original system will be simplified so that a simpler estimation is possible. Using the example of a system which is composed of two rooms, multiple apertures, and a network cable located in both chambers, it is shown that an estimation of the coupled disturbances due to external electromagnetic sources is feasible with this approach. Starting from an incident electromagnetic field, we determine transfer functions describing the coupling means (apertures, cables). Using these transfer functions and the knowledge of the weak coupling paths above, a decision is taken regarding the means for paths that can be neglected during the estimation. The estimation of the coupling into the cable is then made while taking only paths with strong coupling into account. The remaining part of the wiring harness in areas with weak coupling is represented by its input impedance. A comparison with the original network shows a good agreement.
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Olszewski, Jurek. "Evaluation the results of electromagnetic compatibility of a prototype device for ear stimulation in patients with tinnitus". Otolaryngologia Polska 77, n. 6 (16 ottobre 2023): 37–42. http://dx.doi.org/10.5604/01.3001.0053.6157.
Testo completoAbstract (sommario):
<b><br>Aim:</b> The aim of the study was to evaluate the results of electromagnetic compatibility of a prototype device for ear stimulation in patients with tinnitus.</br> <b><br>Material and methods:</b> The electromagnetic compatibility tests of the prototype device for electro- and magnetostimulation of the hearing organ were carried out at the Center for Attestation and Certification Tests OBAC Sp. z o. o. in Gliwice in 2020. The following product standards were used: PN-EN 60601-1-2:2015-11 – medical electrical equipment (general requirements for basic safety and essential functioning; PN-EN 55011:2012 - industrial, scientific and medical equipment [characteristics of radio frequency disturbances] ) PN-EN 61000-3-2:2014-10 – electromagnetic compatibility (EMC), permissible levels of harmonic current emissions (phase load current ≤ 16 A).</br> <b><br>Results:</b> The level of expanded uncertainty in the measurement of conducted disturbances in the range of 0.150–30MHz does not exceed the level specified in the PN-EN-55016-4-2:2011 standard. In the study of the emission of radiated disturbances up to 1GHz in the frequency range of 30–1000MHz (PN-EN 55011:2012 standard), it was found that the setting of the EUT during the tests was in accordance with the requirements of the standard. The level of expanded uncertainty in the measurement of radiated disturbances in the 30–1000MHz range does not exceed the level specified in the PN-EN 55016–4-2:2011 standard. The measured current harmonic levels (phase power supply current ≤16A) with a frequency range of 50Hz–2kHz do not exceed the permissible levels specified in the PN-EN 61000-3-2:2014-10 standard. The test of resistance to the magnetic field at the frequency of the power grid (PN-EN 61000-4-8: 2010 standard also showed that the setting of the EUT during the tests was in accordance with the requirements of the standard and the result was positive.</br> <b><br>Conclusions:</b> Testing of immunity to radiated radio frequency electromagnetic field (PN-EN 61000-4-3:2007 +A1:2008+A2:2011 standard) and testing of resistance to magnetic field at power frequency (PN-EN 61000-4-8 standard :2010) did not exceed the level specified in the standard and showed a positive result. The measured harmonic levels of the network current (phase supply current ≤16A) with the frequency range 50Hz–2kHz do not exceed the permissible levels specified in the PN-EN 61000- 3-2:2014-10 standard for a class A device.</br>
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Hu, Jie, Kou Yamada, Tatsuya Sakanushi, Yuki Nakui e Yusuke Atsuta. "A Design Method for Control System to Attenuate Periodic Input Disturbances Using Disturbance Observers for Time-Delay Plants". ECTI Transactions on Electrical Engineering, Electronics, and Communications 11, n. 1 (12 luglio 2012): 37–46. http://dx.doi.org/10.37936/ecti-eec.2013111.170607.
Testo completoAbstract (sommario):
In this paper, we examine a design method for control system to attenuate periodic input disturbances using disturbance observers for time-delay plants. The disturbance observers have been used to estimate the disturbance in the plant. Several papers on design methods of disturbance observers have been published. Recently, parameterizations of all disturbance observers and all linear functional disturbance observers for time-delay plants with any input disturbance were clarified. If parameterizations of all such observers for time-delay plants with any input disturbance are used, there is a possibility that we can design control systems to attenuate input dis- turbances effectively. However, no paper examines a design method for control system using parameterizations of all disturbance observers and all linear functional disturbance observers for time-delay plants with any input disturbance. In this paper, to attenuate periodic input disturbances effectively, we propose a design method for control system using these parameterizations.
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Jyothiraman, Neelagandan Virchuly, e Viraduchalam Sivachidambaranathan. "Improve the voltage profile of the grid-integrated induction motor with a fuzzy-based voltage source converter". International Journal of Power Electronics and Drive Systems (IJPEDS) 15, n. 2 (1 giugno 2024): 874. http://dx.doi.org/10.11591/ijpeds.v15.i2.pp874-882.
Testo completoAbstract (sommario):
This article suggests installing a series compensator on grid-connected induction motors that allows for the ride-through of unbalanced voltage sag. Fuzzy logic controls the motor voltages in a standard three-phase voltage source inverter or voltage source inverter (VSI). An open-ended three-phase machine and the grid form a series connection for the VSI. The proposed system is well suited for uses where frequency variation is unnecessary, such as with large pumps or fans. There is no requirement for a direct current (DC) source or injection transformer when conducting an electric mutual coupling The severity of the sag in the grid voltage that will prevent EMC from shutting down is proportional to the load on the motors. An increase in the voltage of the DC link may be necessary if the voltage is not balanced. A 1.5 hp four-pole induction motor was used alongside grid voltage disturbances to test the proposed compensator's ride-through capability. Grid's current analysis demonstrates that the proposed system does not require the addition of a passive filter to achieve low levels of total harmonic distortion (THD). Additionally, the control strategy, component ratings, and analysis of the converter's output voltage operating principle and pulse width modulation technique are covered. The system's viability is shown via simulation and experimental results.
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H. Punia, H. Dhiman, H. Saharan e S. Jakhar. "Floristic Composition and Diversity in Response to Varying Degrees of Disturbance in Tropical Dry Deciduous Forests of Southern Haryana, India". Ecology, Environment and Conservation 28, n. 04 (2022): 2164–73. http://dx.doi.org/10.53550/eec.2022.v28i04.079.
Testo completoAbstract (sommario):
The aim of the current investigation was to study the effects of anthropogenic disturbances on the vegetation structure of the three Tropical Dry Deciduous Forests of Southern Haryana i.e., Mandhana, Ghasola, and Mandhiali in the Bhiwani, Charkhi Dadri, and Mahendergarh districts, respectively. The data were collected from March, 2020 to March, 2021. The floristic composition was quantified by randomly placing 15 quadrats per site (45 in total). A disturbance index was developed for each site and high, medium and low disturbance areas were identified based on prevailing disturbances that were found to be maximum for Mandhiali (21), followed by Ghasola (16) and Mandhana (9). Ecological parameters such as frequency, density, abundance, basal area, IVI, and diversity indices were calculated for each siteduring the study. A total of 50 species of plants representing 44 genera and 25 families were observed consisting of 14 trees, 9 shrubs, and 27 herbs during the investigation of floristic composition. The species richness decreased with an increase in the disturbance level on the three sites viz., Mandhana (40), Ghasola (33), and Mandhiali (29) respectively. The value of Shannon Weiner diversity index (H’) and Pielou Index of evenness (E) declined with an increasing disturbance while Simpson index of dominance (Cd) increased as the disturbance levels increased across the three sites. The results offer significant evidence that anthropogenic disturbances in arid regions of South Haryana play a vital role in community structure and composition. In a forest ecosystem, anthropogenic disturbances cause habitat fragmentation along with soil erosion, loss of soil fertility and biodiversity, etc. The selected forests are in urgent need of management activities to check the intensity of disturbances by controlling anthropogenic pressure on these ecosystems and save them from further degradation. Thus, the present study intensifies the need for phytosociological studies crucial for proper management and conservation purposes.
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Kanchanaharuthai, Adirak, Piraporn Konkhum e Kruwan Wongsurith. "A Composite Nonlinear Controller for Power Systems with STATCOM under External Disturbances". ECTI Transactions on Electrical Engineering, Electronics, and Communications 18, n. 2 (31 agosto 2020): 107–17. http://dx.doi.org/10.37936/ecti-eec.2020182.240342.
Testo completoAbstract (sommario):
This paper concentrates on the design of a composite nonlinear stabilizing state feedback control for power systems with static synchronous compensator (STATCOM) with the help of a combination of backstepping strategy and a nonlinear disturbance approach. The disturbance observer is used to estimate unavoidably external disturbances. Thus, the obtained control law can be used to successfully stabilize the system stability and reject undesired external disturbances. In order to demonstrate the effectiveness of the developed process design, numerical simulation results are provided to indicate that the presented composite controller can improve dynamic performances, rapidly suppress system oscillations of the overall closed-loop dynamics, and despite having inevitably external disturbances, performs better than a conventional backstepping control technique.
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Niu, Haoran, Olufemi A. Omitaomu e Qing C. Cao. "Machine Committee Framework for Power Grid Disturbances Analysis Using Synchrophasors Data". Smart Cities 4, n. 1 (22 dicembre 2020): 1–16. http://dx.doi.org/10.3390/smartcities4010001.
Testo completoAbstract (sommario):
Events detection is a key challenge in power grid frequency disturbances analysis. Accurate detection of events is crucial for situational awareness of the power system. In this paper, we study the problem of events detection in power grid frequency disturbance analysis using synchrophasors data streams. Current events detection approaches for power grid rely on individual detection algorithm. This study integrates some of the existing detection algorithms using the concept of machine committee to develop improved detection approaches for grid disturbance analysis. Specifically, we propose two algorithms—an Event Detection Machine Committee (EDMC) algorithm and a Change-Point Detection Machine Committee (CPDMC) algorithm. Both algorithms use parallel architecture to fuse detection knowledge of its individual methods to arrive at an overall output. The EDMC algorithm combines five individual event detection methods, while the CPDMC algorithm combines two change-point detection methods. Each method performs the detection task separately. The overall output of each algorithm is then computed using a voting strategy. The proposed algorithms are evaluated using three case studies of actual power grid disturbances. Compared with the individual results of the various detection methods, we found that the EDMC algorithm is a better fit for analyzing synchrophasors data; it improves the detection accuracy; and it is suitable for practical scenarios.
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Lazaruk, Lance W., Gavin Kernaghan, S. Ellen Macdonald e Damase Khasa. "Effects of partial cutting on the ectomycorrhizae of Picea glauca forests in northwestern Alberta". Canadian Journal of Forest Research 35, n. 6 (1 giugno 2005): 1442–54. http://dx.doi.org/10.1139/x05-062.
Testo completoAbstract (sommario):
This study assessed the impact of various harvesting practices (including those designed to emulate natural disturbances) on ectomycorrhizae (ECM) associated with white spruce (Picea glauca (Moench) Voss) in northwestern Alberta, Canada. Treatments included clearcuts, partial cuts (dispersed green-tree retention with 20%, 50%, and 75% residual live trees, and aggregated green-tree retention), unharvested control sites, and a burned stand. The percentage of active white spruce root tips and ECM richness and diversity, as observed in soil cores collected throughout the study site, all decreased with increasing disturbance intensity. Effects were particularly pronounced in clearcuts, machine corridors used for access by harvesting equipment in the dispersed green-tree retention stands, and in burned areas. Reductions in ECM biodiversity could be attributed to the sensitivity of late-stage ectomycorrhizae (e.g., Cortinarius spp., Lactarius spp., and Russula spp.) to soil disturbances and changes in microclimate associated with harvesting or burning. Areas of dispersed and aggregated green-tree retention were not dramatically different than unharvested forest in terms of root tip density and ECM richness, diversity, and composition. Harvesting practices that retain a percentage of residual live trees, either dispersed throughout the cutting unit or in aggregated patches, could be an effective means of maintaining ectomycorrhizal biodiversity at the stand level.
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Huang, S. T., Jing Feng Zhi, Hao Bo Cheng e W. Zuo. "Robust Position Controller Design for Linear Servo Units Used in Noncircular Machining". Materials Science Forum 471-472 (dicembre 2004): 755–59. http://dx.doi.org/10.4028/www.scientific.net/msf.471-472.755.
Testo completoAbstract (sommario):
This paper presents the design and implementation of a robust motion control structure for linear servo units used in noncircular machining. Compared with ball/screw driven system, the controller of the linear motor driven system must provide a high level of disturbance rejection performance, as the system is more sensitive to force disturbances and parameter variations. Thus, in this paper, a robust feedback controller based on disturbance observer is applied to enhance the stiffness and robustness. A magnitude and phase regulating control scheme (MPRC) is proposed to improve the system tracking accuracy, and a simple error feedforward compensator (EFC) further reduces the feedforward control error that result from inaccurate frequency response data. The effectiveness of the proposed controller is demonstrated by experiments.
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An, Guang Pei, Wei Dong Zhang, Xiang Cui e Chong Qing Jiao. "EMC on Fiber-Optic Transceivers under EFT". Applied Mechanics and Materials 336-338 (luglio 2013): 96–99. http://dx.doi.org/10.4028/www.scientific.net/amm.336-338.96.
Testo completoAbstract (sommario):
Under high voltage and ferromagnetic condition, the optical fiber, as the new communication carrier, is widely used in power signal transmission. However, the interference rejection performance of optical-fiber transceiver, an important part of photoelectric conversion, has always been of great concerns. Whether the optical fiber transceiver works properly or not, will directly affect the quality of the whole communication network. This paper focuses on the time-domain and frequency-domain features of power ports and control ports under the strong transient electromagnetic disturbance. At the same time, this paper makes use of magnetic toroid to suppress electromagnetic interference (EMI). The results provide a reference for future anti-jamming design of optical-fiber transceivers.
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Veselá, Petra, Martina Vašutová, Karolína Hofmannová, Magda Edwards-Jonášová e Pavel Cudlín. "Ectomycorrhizal Community on Norway Spruce Seedlings Following Bark Beetle Infestation". Forests 10, n. 9 (28 agosto 2019): 740. http://dx.doi.org/10.3390/f10090740.
Testo completoAbstract (sommario):
Ectomycorrhizal (ECM) fungi importantly influence seedling growth, nutrition, and survival and create an extensive mycelial network interconnecting tree species and enabling resource redistribution. Due to their symbiotic relationship with trees, they are impacted by forest disturbances, which are of increasing relevance due to climate change. The effect of disturbance on seedling colonization and their morphology is still largely unknown. Seedling growth parameters and the ECM fungal assemblage on the roots of Norway spruce (Picea abies (L.) H. Karst.) seedlings were assessed in mature spruce forests attacked and destroyed by bark beetle and in a mature non-attacked forest as a reference. We did not detect significant differences in number of ECM species on seedling roots among forest types, but ECM species composition changed; Tylospora fibrillosa (Burt) Donk, Meliniomyces variabilis Hambl. & Sigler, and Phialocephala fortinii C.J.K. Wang & H.E. Wilcox were characteristic species in the forest destroyed by bark beetle, whereas Lactarius, Cortinarius, and Russula were in the mature forest. Forest type further significantly influenced the height, root length, and root collar thickness of seedlings and the proportion of exploration types of mycorrhizae.
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Mao, Jian Zhou, Yan Hui Wang, Nan Si e Hui Cheng Xia. "Research on EMC Evaluation of Shipborne Electronic Equipment". Applied Mechanics and Materials 556-562 (maggio 2014): 1998–2001. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.1998.
Testo completoAbstract (sommario):
The paper addresses the central issues of electromagnetic compatibility (EMC) evaluation of shipborne electronic equipment. The mutual disturbance between equipments would show important influence on the capability of the devices, slight interferer may degrade the performance, severe interferer would make the equipment out of work even cause false action of weapon system, therefore, how to quantitatively describe the EMC state of equipment and harmonize the EMC assessments correctly is the key consideration of the warship’s commander and the combat system designer. Take the advantage of norm theory this paper proposed a method to evaluate the EMC state of the shipborne electronic equipment quantitatively, which would meet the requirements both warship’s EMC design and commander’s campaign operation.
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Munje, Ravindra, Ranvir Desai e Balasaheb Patre. "Observer-Based Integral Sliding Mode Controller for a Two-Wheeled Inverted Pendulum". ECTI Transactions on Electrical Engineering, Electronics, and Communications 21, n. 1 (28 febbraio 2023): 248610. http://dx.doi.org/10.37936/ecti-eec.2023211.248610.
Testo completoAbstract (sommario):
The modeling and control of a two-wheeled inverted pendulum (TWIP) is gaining much interest due to the various advancements in hardware and computing technologies. A TWIP system has many advantages and applications. However, it still faces many challenges such as positioning, disturbance rejection, parameter uncertainties, etc. In this paper, a control scheme based on modern control techniques is presented to overcome these issues. Furthermore, an observer-based robust integral sliding mode controller (ISMC) is proposed for the nonlinear TWIP system. Firstly, a robust integral sliding mode controller is designed to tackle short-term and long-term constant and time-varying disturbances as well as issues relating to parameter variation. Secondly, the reduced-order observer is designed to estimate immeasurable states, enabling simplified implementation. It is then applied to the nonlinear model of the TWIP system, and performance is observed under different transient conditions. A comparison with prevalent controllers in the literature is carried out. This comparison relates to graphical results, time domain specifications, and error performance indices, calculated for states. From this, a significant qualitative improvement can be observed with the proposed controller for all types of transients. In quantitative terms, zero steady-state error with disturbances and a five-fold improvement in settling time with parameter variations are observed. This paper also discusses the software Simulink realization for modeling and control of the TWIP system, which can be valuable for novices working in this area.
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Kranabetter, J. M. "Ectomycorrhizal community effects on hybrid spruce seedling growth and nutrition in clearcuts". Canadian Journal of Botany 82, n. 7 (1 luglio 2004): 983–91. http://dx.doi.org/10.1139/b04-077.
Testo completoAbstract (sommario):
A diverse community of ectomycorrhizal (ECM) fungi is generally considered beneficial to forest ecosystems, but the function of ECM communities should be considered within an ecological context. The growth of hybrid spruce (Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière) seedlings was compared after transplanting into recent clearcuts, where soil moisture and nitrogen are typically readily available. The seedlings had either a "forest" ECM community (taken from forest gap edges) or a "pioneer" ECM community (taken from disturbed road edges) and were planted at wide and close spacing. After 3 years, morphotype distribution and abundance (64% community similarity between "forest" and "pioneer" seedlings) overlapped considerably, but height growth was 25% greater for the "pioneer" seedlings. There was a reduction in diameter at close spacing, with little difference in competition effects between ECM communities. There were no differences detected in foliar nitrogen concentrations and no evidence of nitrogen or phosphorus deficiencies. The advantage of fungi such as Amphinema byssoides, Thelephora terrestris, and Laccaria laccata might be the proliferation of fine roots that allows for the fullest utilization of abundant soil resources. The results suggest that the ECM communities arising after clearcut disturbances are well adapted to these initial soil conditions.Key words: ectomycorrhiza, disturbance, diversity, productivity, competition, Picea glauca.
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Hassan, Saeed Kazem, e Eftkar Mahdy Al-Najar. "Studying the relationship between advanced oxidative stress of protein and uterine disturbance in dairy cows". Journal of Kerbala for Agricultural Sciences 10, n. 3 (23 marzo 2023): 29–37. http://dx.doi.org/10.59658/jkas.v10i3.1116.
Testo completoAbstract (sommario):
The study was conducted on 100 dairy cows in Tag-Alnahrain station, located in Al-Qadysia province, post parturition (after 40-60) days after calving. The aim of the study was to test the relationship between oxidative stress, particularly protein oxidation, and uterine health during the puerperium. The cows are divided into four groups according to intense clinical sighs of merit. In order to distinguish between degrees of inflammation, in this study, the cutoff value of PMN %. was set at 8% to distinguish between degrees of inflammation. The group (H) was (54). The SCE group consisted of 22 cows infected with subclinical endometritis, the EM1 group consisted of 11 cows infected with clinical endometritis Grade 1, and the EM2 group consisted of 13 cows infected with clinical endometriosis Grade 2. The advanced oxidation protein product (AOPP) was estimated in plasma and vaginal mucus discharges by using a commercial laboratory method to detect the dityrosin formation, which is the major content of AOPP. AOPP, a good marker of protein oxidation, was visualised by western blot,. The study demonstrated that there was an increase in plasma AOPP in the EM2 group with a significant value of p 0.01.The study also showed a significantly increased concentration of AOPP in vaginal mucus discharges in the group of animals infected with (SCE). The study clarified that there was an increase in neutrophil point age of more than 8% in vaginal mucus discharge after collecting mucus by metrecheek in the (EM1) group with a significant value of p≤0.0l while it was significantly(p≤0.01) in uterine mucus collected by cytobrush.
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Kane, Makarand M., Nathaniel Taylor e Daniel Månsson. "Electromagnetic Interference from Solar Photovoltaic Systems: A Review". Electronics 14, n. 1 (25 dicembre 2024): 31. https://doi.org/10.3390/electronics14010031.
Testo completoAbstract (sommario):
Rapid expansion of solar photovoltaic (PV) installations worldwide has increased the importance of electromagnetic compatibility (EMC) of PV components and systems. This has been highlighted by interference reported from PV installations (PVI) in the Netherlands, the United States, Sweden, etc. Significant research and development efforts are seen in the domain of enhancing efficiency and economic viability of PVI, whereas the EMC aspects have received less attention and are mainly focused on the PV system acting as a victim of lightning and a victim of changing grid impedance. This article presents a review of the important EMC aspects of PVI as a disturbance source. It has the following main parts: (a) reported cases of emissions and interference from PV installations; (b) modeling and analysis of PV subcomponents from an EMC perspective; and (c) the main standards related to the topic. Mitigation techniques for improving EMC aspects of PVI are also described, along with suggested directions for future research. The compilation brings together wide-ranging sources, both for EMC engineers who want to understand the EMC context of PV systems and for PV system designers seeking to improve EMC performance.
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Pawłowicz, Grzegorz. "Methods of Improving EMC for Ticket Validator According to UNECE Regulation No. 10.06". Pomiary Automatyka Robotyka 25, n. 3 (13 settembre 2021): 87–93. http://dx.doi.org/10.14313/par_241/87.
Testo completoAbstract (sommario):
The article presents the results of measurements and design changes to the certain electronic device, the purpose of which was to meet the requirements for the levels of electromagnetic disturbance emission from the device in accordance with the UNECE Regulation No. 10.06. The successive stages of the research are described. The subsequent modifications of the device in accordance to the research findings are also described. The subject of the research was the validator of paper and electronic tickets, enabling the purchase of tickets with the use of a contactless payment card and a city card. In the course of the research, the effectiveness of selected methods of ensuring the electromagnetic compatibility of the device was presented.
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Xu, Zhifei, Blaise Ravelo, Olivier Maurice, Jonathan Gantet e Nicolas Marier. "Radiated EMC Kron's Model of 3-D Multilayer PCB Aggressed by Broadband Disturbance". IEEE Transactions on Electromagnetic Compatibility 62, n. 2 (aprile 2020): 406–14. http://dx.doi.org/10.1109/temc.2019.2901670.
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Romito, F., C. Cormio, S. De Padova, V. Lorusso, M. A. Berio, F. Fimiani, A. Piattelli et al. "Patients attitudes towards sleep disturbances during chemotherapy". European Journal of Cancer Care 23, n. 3 (16 agosto 2013): 385–93. http://dx.doi.org/10.1111/ecc.12106.
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Rúa, Megan A. "Characterizing Ectomycorrhizal Fungal Community Structure and Function of Two Varieties of Pinus clausa That Differ in Disturbance History". Forests 12, n. 2 (13 febbraio 2021): 219. http://dx.doi.org/10.3390/f12020219.
Testo completoAbstract (sommario):
Despite the immense amount of diversity present in the soil biota, the ecological and evolutionary processes that regulate species diversity and abundance of ectomycorrhizal (ECM) fungi across space and time remain elusive. In forest ecosystems, ECM fungal diversity may be maintained by periodic disturbances which operate at different time scales due to their effects on host genetic and phenotypic characteristics and the associated environment. To investigate the degree to which these factors shape ECM fungal community composition and function, I sampled 10 independent sites for a pine species indicative of an endangered ecosystem, the Florida scrub, where disturbance history has driven the divergence of a single species into two genetically distinct varieties (Pinus clausa var. immuginata and var. clausa). A total of 300 ECM fungal species were identified based on rDNA ITS sequences, but each variety harbors different ECM species composition and function. A follow-up greenhouse experiment, in which the seed from each variety was grown in its own soil (“home”) and in the soil of the other variety (“away”), suggests these communities differentially impact the growth of their host seedlings. While var. clausa seedlings had the same total biomass regardless of soil origin, var. immuginata had higher biomass in their own soil compared to var. clausa. This is likely due to an increased number of ECM colonized tips in the home soil compared to in away soil. Taken together, these results may suggest different evolutionary histories where structure host genetic and phenotypic characteristics may be important for structuring their dynamics with ECM fungi.
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Thongsan, Taweesak, e Theerayuth Chatchanayuenyong. "Simple and Fast Voltage Disturbance Detection and Voltage Reference Generation Approach for Dynamic Voltage Restorer (DVR) to Compensate Unbalanced Voltage Sag and Swell in Three-Phase System: Simulation and Experimental Testing". ECTI Transactions on Electrical Engineering, Electronics, and Communications 21, n. 1 (28 febbraio 2023): 248611. http://dx.doi.org/10.37936/ecti-eec.2023211.248611.
Testo completoAbstract (sommario):
The dynamic voltage restorer (DVR) is an important device for coping with voltage sag, swell, and unbalance. However, it is a real-time mechanism and must operate as quickly as possible to protect the sensitive and critical load from supply-side voltage anomalies. Hence, fast detection of voltage disturbances and reference voltage generation is essential for the DVR. This paper proposes a simple and fast voltage disturbance detection approach based on a simple three-phase phasor diagram which is easy to implement. The controller employed for the DVR uses a sliding mode control, making the entire system robust and insensitive to system parameter variations. Three different scenarios are simulated according to arbitrarily imposed supply conditions, verified in laboratory tests using the DSP R&D controller board. The results demonstrate a simpler, faster voltage-anomaly detection process which is easier for implementation compared to the other methods in the literature. The best and worst detection times (DTs) of the proposed approach are 1 and 4 ms, respectively. It yields a rapid response, accurate compensation, and robustness in restoring the load voltage to its nominal value within two cycles.
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YAYOU, Ken-ichi, Makio TAKEDA, Hirokazu TSUBONE, Shigeru SUGANO e Kunio DOI. "The Disturbance of Water-Maze Task Performance in Mice with EMC-D Virus Infection." Journal of Veterinary Medical Science 55, n. 2 (1993): 341–42. http://dx.doi.org/10.1292/jvms.55.341.
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Liu, Xueming, Ping Sun, Ta Zhao, Gang Song, Caixin Fu, Weiping Liu e Tewabe Chekole Workneh. "Research on EMC Optimization of Wireless Electric Field Sensor for Rail Vehicle". Journal of Sensors 2022 (11 aprile 2022): 1–7. http://dx.doi.org/10.1155/2022/7515281.
Testo completoAbstract (sommario):
In order to improve the electromagnetic compatibility of railway vehicle wireless electric field sensor, a research on electromagnetic compatibility optimization of railway vehicle wireless electric field sensor is proposed. The results show that the optimized RF radiation energy is greatly reduced from 60 to 20, which is completely lower than the standard limit of radiation disturbance, and meets the requirements of EMC design of electronic products. The feasibility and effectiveness of the optimal design are proved. The experimental results show that the test results meet the requirements of general technical conditions of electromagnetic compatibility of speed sensor, which indicates that the electromagnetic compatibility design proposed can be popularized and applied.
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Agiananda, Feranindhya, Tiara Nugraeni, Hervita Diatri, Tiara Aninditha e Profitasari Kusumaningrum. "Factors Influencing Distress and Coping Strategies Among Patients with Metastatic Spinal Tumor at Cipto Mangunkusumo General Hospital". Indonesian Journal of Cancer 17, n. 4 (22 dicembre 2023): 272. http://dx.doi.org/10.33371/ijoc.v17i4.994.
Testo completoAbstract (sommario):
Background: Patients with metastatic spinal tumor are experiencing various symptoms, including neurological deficits that cause distress and affects their quality of life. The vulnerability to distress is influenced by coping strategies. Therefore, this study aimed to investigate factors associated with distress and coping strategies in patients with metastatic spinal tumors at Cipto Mangunkusumo General Hospital. Methods: In a cross-sectional study conducted at Cipto Mangunkusumo General Hospital from September 2021 to May 2022, factors associated with distress and coping strategies in patients with metastatic spinal tumors were investigated. The analysis included a total of 104 subjects from both outpatient and inpatient settings. Distress levels and areas of concern were assessed using the Distress Thermometer (DT) questionnaire while coping strategies were evaluated through the Coping Orientation to the Problem Experienced (COPE) instrument. Bivariate and multivariable analyses were carried out to assess the relationship between sociodemographic factors, spinal tumor characteristics, specific areas of concern, coping strategies, and distress.Results: The results showed that 57.7% of metastatic spinal tumor patients experienced distress. In the 18-59 age group, motor disorders, sensory disturbances, autonomic disorders, treatment status, problem-focused coping (PFC), emotion-focused coping (EFC), and avoidance coping had significant associations with distress. However, the multivariable analysis showed that EFC (OR = 1.156, 95% CI: 1.024–1.304, p=0.019), avoidance coping (OR = 1.154, 95% CI: 1.005–1.326, p=0.042), and sensory disturbance (OR = 16.001, 95% CI: 1.472–173.960, p=0.023) were identified as risk factors for distress.Conclusions: Patients with metastatic spinal tumors who used emotion-focused coping, avoidance coping, and sensory disturbance faced significant risk factors for distress
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Fernaldo, Aggasy Problema, e Asrul Sani. "SISTEM PAKAR DIAGNOSA GANGGUAN MESIN EDC MENGGUNAKAN METODE FORWARD CHAINING PADA BANK INDONESIA". EBID:Ekonomi Bisnis Digital 1, n. 2 (31 dicembre 2023): 231–40. http://dx.doi.org/10.37365/ebid.v1i2.228.
Testo completoAbstract (sommario):
An EDC (Electronic Data Capture) machine is an electronic device used to collect, store and manage electronic payment transaction data, such as credit or debit cards. Typically, EDC machines are used by merchants or retailers to accept payments from customers by credit or debit card. EDC machines connect to electronic payment networks and facilitate secure data transfer between customer cards and payment systems. The aim is to implement the forward chaining method and create an expert system that can diagnose EDC machine damage and disturbances. The forward chaining method is used in this research. The result is that the forward chaining method can be implemented in an expert system and the system can be used to diagnose damage and disturbances to EDC machines.
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Yamada, Kou, Iwanori Murakami, Yoshinori Ando, Masahiko Kobayashi e Yoichi Imai. "The Parameterization of All Disturbance Observers for Time-Delay Plants". ECTI Transactions on Electrical Engineering, Electronics, and Communications 9, n. 1 (6 luglio 2009): 40–48. http://dx.doi.org/10.37936/ecti-eec.201191.172263.
Testo completoAbstract (sommario):
We examine the parameterization of all disturbance observers for time-delay plants. Disturbance observers have been used to estimate unknown disturbance in plants. There have been several works on design methods of disturbance observers for time delay plants but no published work on the parameterization of all disturbance observers for time-delay plants. We propose the parameterization of all disturbance observers for time-delay plants and that of all linear functional disturbance observers for time-delay plants.
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Fořt, Jiří, e Martin Pittermann. "Analysis of Influence on the Grid of Input Part of Special Power Source 113 kW / 1 kA DC". TRANSACTIONS ON ELECTRICAL ENGINEERING 7, n. 1 (30 marzo 2020): 1–9. http://dx.doi.org/10.14311/tee.2018.1.001.
Testo completoAbstract (sommario):
This paper compares some variants of power circuit configurations for a special power DC source 110 V / 1 kA. The requirement for the source was to ensure minimum ripple of the output current and reduced EMC-disturbance generated from this DC-source to the supply network and to other surrounding equipments.
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Frick, M., R. Eidher e R. Weigel. "Coupling path influence on the conducted emission measurement results by the EMC semiconductor test board". Advances in Radio Science 9 (1 agosto 2011): 303–8. http://dx.doi.org/10.5194/ars-9-303-2011.
Testo completoAbstract (sommario):
Abstract. The fact of reduced development time in the automotive sector requires a change in the electromagnetic compatibility (EMC) validation of electronic components. To increase the development time of automotive components, e.g. sensors or electronic control units (ECUs), it is mandatory to verify the EMC behavior of the integrated circuit (IC) itself in an early development stage simultaneous to the development process of the entire ECU into which it is embedded. The conducted IC EMC tests emission as well as immunity is realized with a specific test printed circuit board (PCB) which is built according to the guidelines of the Bosch, Infineon, Siemens VDO Specification (BISS, 2007). The measurement results of these EMC tests are affected by the test PCB itself. To deduce the application requirements of the component from the application circuit of the test PCB it is necessary to consider this influence by the printed circuit board. The text at hand gives an overview on how far the emission results are adulterated by the used test PCB. The presented method also grants a validation of the disturbance voltage directly at the IC pin considering the application circuit.