Kind Of Filter Research Articles

On Constant Resistance Filter Design with Dissipative Elements

The advantage of constant resistance filters, as compared to active filters, is that any number of such filters can be cascaded - either to sharpen or broaden the response or for designing other kinds of filters, without being sensitive to temperature or other environmental effects. Also, although using lossy elements involves a larger number of components as compared to that using lossless components, the former is a practical design, while the latter is an ideal one and cannot be realized in practice. It is proved here that the circuit for constant resistance filter designed with dissipative elements, proposed earlier in the literature, is a versatile one, in that by properly designing or reorienting, it can perform the functions of a band-pass, band-stop, low-pass as well as high-pass filters.

Stabilization of a 4D financial system with disturbance and uncertainty by UDE-based control method

The stabilization of the 4D financial system involving the external disturbance and uncertainty is investigated extensively. Firstly, two types of controllers (us) are proposed to stabilize the nominal 4D financial system which is not impacted by the external disturbances. Secondly, three kinds of filters are designed, based on which, three categories of uncertainty and disturbance estimators (uude) are presented and used to asymptotically counteract the lumped disturbance and uncertainty (ud), i.e., buude=−uˆd→−ud, as t→∞, where uˆd is the estimate of ud and b is a known vector. Consequently, the stabilization problem of such a system is implemented by the combined controllers (u=us+uude). It is noted that the obtained controllers are single input controllers, and thus easy to be implemented in applications. Finally, the proposed theoretical results are demonstrated and verified by the computer simulation.

Innovative culture in personnel management in transport industry of Ukraine

Methods. The main methods used in the work are analysis and synthesis. With their help, the role and significance of innovative culture in the personnel management system of transport industry enterprises were determined (general theoretical principles, determinants of the formation of innovative culture and its practical implementation). The methods of generalization and system analysis made it possible to determine the system of principles on which the innovative culture in the personnel management system of enterprises should be based. Results. On the basis of the conducted study of approaches to determining the essential content of the concept of «innovative culture», the article examines the views of domestic scientists on the factors of formation and improvement of innovative culture in the context of personnel management. The role and place of innovative culture in the process of implementing the innovative strategy of enterprise development is determined. The main tasks and principles of forming an effective innovative culture in the context of personnel management in the transport industry are highlighted. The main functions of innovative culture in the personnel management system of the enterprise are substantiated. Novelty. The innovative culture of enterprises in the transport sector will contribute to the formation of its positive image among external counterparties (partners, consumers, potential employees, etc.), as one that actively develops and implements innovative ideas and is open to the perception of a new idea. Activities in the conditions of an effectively formed innovative culture stimulate specialists to reveal and realize their potential through the constant generation, selection, testing and implementation of new ideas. As a result of passing all stages of the innovation process – from the emergence of an innovative idea to its implementation – new knowledge, abilities, skills and experience are accumulated. Practical value. It is substantiated that innovative culture motivates enterprises of the transport industry to choose simple, clear goals and develops the desire of all personnel for innovative development. Innovative culture reflects the holistic orientation of personnel, fixed in motives, knowledge, abilities and skills, as well as in styles and norms of behavior. The constant updating of the «abilities» of the personnel contributes to the increase of the economic effect for the enterprise, the formation of a stable workforce of highly qualified employees. Innovative culture acts as a kind of filter on the way of introducing all innovations.

Why most papers on filters are really trivial (including this one)

The aim of this note is to show that many papers on various kinds of filters (and related concepts) in (subreducts of) residuated structures are in fact easy consequences of more general results that have been known for a long time.

Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters).

In many situations in everyday life, sunlight levels need to be reduced. Optical filters with asymmetric transmittance dependent on the incident angle would be useful for sunglasses and vehicle or architectural windows, among others. Herein, we realized the production of optical filters, called "louver filters", comprising HAN-type LC film produced using liquid crystalline ink with dichroic dyes. For the formation of the HAN-type LC film, the liquid crystalline ink was aligned on a rubbed polyimide layer and polymerized by UV irradiation. Two kinds of filters are proposed: one is a filter composed of HAN-type LC film and a polarizer, and the other is composed of two HAN-LC films with a half-wave plate between them. The dependence of the asymmetric transmittance on the incident angle was confirmed for these filters. The dependence changed depending on the pretilt angle of the alignment layers. Photographs taken with the optical filters displayed their effectiveness.

Closed and Open Maps for Partial Frames

This paper concerns the notions of closed and open maps in the setting of partial frames, which, in contrast to full frames, do not necessarily have all joins. Examples of these include bounded distributive lattices, sigma - and kappa -frames and full frames. We define closed and open maps using geometrically intuitively appealing conditions involving preservation of closed, respectively open, congruences under certain maps. We then characterize them in terms of algebraic identities involving adjoints. We note that partial frame maps need have neither right nor left adjoints whereas frame maps of course always have right adjoints. The embedding of a partial frame in either its free frame or its congruence frame has proved illuminating and useful. We consider the conditions under which these embeddings are closed, open or skeletal. We then look at preservation and reflection of closed or open maps under the functors providing the free frame or the congruence frame. Points arise naturally in the construction of the spectrum functor for partial frames to partial spaces. They may be viewed as maps from the given partial frame to the 2-chain or as certain kinds of filters; using the former description we consider closed and open points. Any point of a partial frame extends naturally to a point on its free frame and a point on its congruence frame; we consider the closedness or openness of these.

Разработка фильтрующе-сорбирующих материалов в целях формирования ассортимента современных фильтров для противогазов и респираторов

The article focuses on the study of filter-sorbing materials (FSM) for the development of small-sized filters and the formation of a modern filters range for gas masks and respirators. There are various kinds of filters, namely particle filters, consisting of a filter material (FM) with protection from aerosols; gas filters, consisting of coal charge with protection from various concentrations of dangerous gases and vapors and combined filters, including anti-aerosol and gas protection. But in industry, due to the improvement of working conditions at enterprises, personal respiratory protection equipment is needed both from aerosols and from low concentrations of dangerous gases and vapors in the air of the working area. The creation of a new small-sized filter with a single filter-sorbing element with low resistance to air flow during breathing is an actual task. In order to form an assortment of modern filters for gas masks and respirators, we studied FSM in the form of polymer or glass fibers sprayed with carbon particles. An experimental series of studies based on the use of FSMs with adsorbents has been carried out, activated carbon (AC) and various absorbers were obtained by impregnation of AC. It is determined that the impregnation of AC with special additives allows for additional protection from inorganic and acid gases and vapors, from ammonia. Comparative tests of the FSMs were carried out with the analysis of the research results. Optimal FSMs have been determined. The fractional composition of coal particles is determined depending on the method of their application. The sorption properties of the obtained FSMs are determined. In this work, for the first time, the combination of a filter material with AC impregnated with chemical additives in particle filters was tested and evaluated. The effect of a combination of AC and a fibrous semi-finished product on the properties of FSM has been studied.

Design, manufacturing and properties of controllable porosity of ceramic filters based on SLA-3D printing technology

The ceramic foam filters are commonly applied in metal casting. However, this kind of filter has a number of drawbacks, such as weak impact resistance, uncontrollable technical parameters, and a long producing cycle. Our work developed a better manufacturing method for ceramic filters based on SLA-3D printing technology in which the structure of filters can be designed according to demands of porosity and hole density. Firstly, it is to propose a ceramic filter model with good mechanical properties under various porosities and hole densities using mechanical simulation and topology optimization. Secondly, SLA-3D printing technology was used to manufacture ceramic filter models with various characteristics. The results demonstrate that the porosity can be achieved with a wide range, and the higher porosity and hole density can approach 90% and 50 PPI, respectively. The preparation error of the internal pillars inside the filters model also can be revised to precisely control the porosity error of filters. Finally, the pore characteristics and compressive performance of the SLA printed ceramic filters were much better than that of the ceramic foam filters.

An Efficient Ash Cleaning Method for Flat Box Cartridge Filter: Structure, Parameters and Cleaning Mechanism of Slotted Blowing

The problem of serious ash accumulation at the lower part of flat box filter cartridges is an important limitation for the improvement of ash cleaning efficiency in this kind of filter. To solve the above-mentioned problem, the type of slotted blowing hole impacting the performance of the ash removing under the same ash cleaning area was studied. In the present work, a total of four types of slotted blowing holes with different length were designed. The influence of blowing distance and blowing pressure on dust removal performance were investigated. Numerical simulation was conducted to demonstrate the mechanism of the dust removal process. An industrial coating test was also carried out to investigate and verify the actual ash cleaning performance under the optimal conditions as obtained from the above investigations. The results showed that: (1) the performance of dust cleaning produced by a three-slit blowhole was better than that by a four-slit blowhole; (2) 0.2 MPa was determined to be the optimal blowing pressure, which meets the requirement of ash cleaning; (3) 20 mm was selected as the optimal blowing distance, as this was the distance at which the surface side wall pressure at the non-positive-to-blow hole area was obviously increased, indicating that the whole performance of ash cleaning could be improved. The results obtained in this study are of great significance for improving the efficiency of dust removal in the use of flat box filters, promoting the development of dust removal technology, protection of environment, and reduction of human health damage.

The Blood-Brain Barrier in Neuroimmune Interactions and Pathological Processes.

The blood-brain barrier (BBB) is a kind of filter, highly selective in relation to various types of substances. The BBB supports the immune status of the brain and is an important regulator of neuroimmune interactions. Some of the molecular and cellular features of the BBB, as well as the five main pathways of neuroimmune communication mediated by the BBB, are analyzed in this article. The functions of the BBB in neuroimmune interactions in various diseases are discussed: multiple sclerosis and Alzheimer's and Parkinson's diseases. The latest data on BBB dysfunction in COVID-19 coronavirus infection caused by the SARS-CoV-2 virus are considered.

Role of neurodidactics in teacher professionalization for online teaching in higher education

The objective of this article is to perform a bibliometric analysis that helps to delimit and understand the concepts of Neuroscience and Neurodidactics, taught in higher education, for a better understanding of the different learning processes, that is, to try to explain what, how and why we learn. A quantitative-bibliometric methodology was employed using the Web of Science (WoS) database. The search was performed by filtering "subject and key terms" in both titles and abstracts of scientific papers using Boolean operators and truncations. We proceeded to work with two samples: the first one without using any kind of filter or refinement of 60 scientific papers; the second one filtering by the thematic categories with a sample of 44 scientific papers. The years of production, the sources of information, the authors and the keywords of the scientific documents were considered for the analysis of the data. From the results shown through the maps, a total of five research fronts have been inferred as the most relevant and related to the topic: neurodidactics in general; neuroscience and technology; neurodidactics and technological aspects; neuroeducation programs and pedagogy and neurodidactics. As this is a developing field of study, no major specific problems have been found, but for the time being what is obtained is a broad and general view of this area of research. Future studies that complement or expand this work could be oriented towards conducting replication research.

Answering three questions about networking research

Researchers often talk about specific technical trends or research topics. But we rarely talk about how and why we do the research that we do. The process of submitting and reviewing papers puts our ideas through a particular kind of filter that may make all of the research seem like it follows some standard rubric, a SIGCOMM Normal Form if you will. During a panel at HotNets'21, five researchers---Hari Balakrishnan, Jon Crowcroft, Jennifer Rexford, Scott Shenker, and David Tennenhouse---each answered three questions about how they pick their own research topics, what areas they would like to see more research on, and how they evaluate conference papers. Due to the unexpectedly positive response to that panel, CCR will be publishing a series of answers to these three questions, starting with two participants from the panel but reaching out to others to provide answers from a broader cross-section of the SIGCOMM community.

Совершенствование процессуального порядка проверки поводов и оснований для возбуждения уголовного дела

Introduction: the range of tasks facing the stage of initiating a criminal case is quite diverse, which leads to different interpretations of their content by the scientists-processualists. The authors of the paper assess the problems of determining the reasons and grounds for initiating a criminal case. The problem considered by the authors of the manuscript is relevant because of their insufficiently clear legislative definition and their related ambiguous interpretation. The purpose of the study: to identify the problems that hinder the improvement of the procedural order for checking the reasons and grounds for initiating a criminal case. The research objectives: to analyze the points of view of the scientists-processualists about the expediency of eliminating the first stage of the criminal process; to offer some recommendations for transforming the stage of initiating a criminal case. Methods: the methodological framework for the study is represented by a system of methods of scientific cognition, which should include: general scientific, systemic, institutional, and comparative legal. Results: the paper provides an assessment of the position of some researchers specializing in criminal procedure law on the need to eliminate the stage of initiating a criminal case, which the authors of the paper do not share, citing the following arguments: the considered stage of the criminal process acts as a kind of filter that separates the law enforcement agencies from procedural activities for the analysis of information that does not hide the signs of a criminally punishable act; will cause an increase in the burden on investigators and interrogators; the burden on the federal budget will increase due to the procedural costs. Conclusions: considering the possibility of improving the stage of initiating a criminal case, borrowing the experience of the representative countries of the Anglo-Saxon legal system, the authors of the paper conclude that as a result of this, the procedural status of some participants in the criminal process will change, which is alien to the Russian criminal procedure legislation: the replacement of the functions of the investigator by the prosecutor and the court; the exercise of the function of the body of inquiry by the investigator; the acquisition by the defender of the status of the subject of proof on a par with the investigator and the inquirer. It is noted that the attempt of the legislator to give evidentiary value to the information obtained during the preinvestigation check as an independent reason for initiating a criminal case was not successful.

Конкурентные преимущества как элемент стратегии образовательной организации (на основе методологии В. Л. Квинта)

Competitive advantages are an important economic category that is receiving close attention from researchers. Any organization needs to have distinctive characteristics in order to distinguish it from other market participants. This rule is also relevant for educational organizations that operate in the educational services market, which is characterized by a stable increase in the level of competition. Thus, the relevance of this study is due to the necessity to find optimal methods for solving the problem of competition between educational organizations in the higher education system. The purpose of the study is to reveal the essence of the competitive advantages of an educational organization, as well as to study the factors contributing to their formation and development. In accordance with the goal, the following tasks are set: to reveal the content of the competitive advantages of an educational organization; to formulate the factors characterizing the competitiveness of an educational organization; put forward recommendations related to the formation and development of competitive advantages of an educational organization. The theoretical and methodological basis of the research is the scientific achievements of domestic and foreign scientists on the issues of managing the competitiveness of an economic entity, including an educational organization. The author’s scientific conclusions are based on the theory of strategy and the methodology of strategizing by the outstanding scientist V. L. Kvint. To substantiate the achieved results, a set of scientific methods and approaches were used: analysis and synthesis, generalization, analogy, scientific theory. As a result of the research, based on the theory of strategy and the methodology of strategizing by V. L. Kvint, the essence of the competitive advantages of an educational organization as an element of its strategy is revealed. It is concluded that competitive advantages are an essential element of the strategic architecture, which, firstly, ensures the effectiveness of the strategy, and secondly, is a kind of filter in the goal-setting system of an educational organization. A number of recommendations related to the management of the competitive advantages of an educational organization are put forward.

Accurate Determination, Matrix Effect Estimation, and Uncertainty Evaluation of Three Sulfonamides in Milk by Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the most commonly used method for sulfonamide determination. Its accuracy, however, can be affected by many factors. In this study, sulfadiazine (SDZ), sulfadimidine (SMZ), and sulfadimethoxine (SDM) in milk were selected to investigate an accurate determination method and the potential influencing factors in the use of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Milk samples were extracted by 25 mL perchloric acid solution (pH = 2) and cleaned up using HLB solid-phase extraction (SPE) cartridges. Four kinds of filters, including PTFE, GHP, nylon, and glass fiber, were compared, and PTFE was selected since it had the best recoveries of target sulfonamides (SAs). Three quantitative methods, including external standard (ES), matrix matching (MM), and isotope dilution mass spectrometry (IDMS), were compared, among which IDMS exhibited the best accuracy. The matrix effect under different mobile phase compositions and of different sample matrices were evaluated and discussed. Ion suppression effects were observed during the determination of all SAs, which got stronger with the increase of the methanol composition percent in the mobile phase. After correction by IDMS, the matrix effect could be neglected. Matrix spiked recoveries at three spiked levels (1 μg/kg, 10 μg/kg, and 20 μg/kg) ranged from 96.8% to 103.8% by IDMS. The expanded relative uncertainties were in the range of 2.02% to 5.75%. The method exhibited wide application range, high accuracy, good stability, and high sensitivity.

Travelling across subspecies borders: songs and calls of the Common Chaffinch Fringilla coelebs in the contact zones and adjoining areas of southern Russia

ABSTRACT Capsule Although many acoustic signals of Common Chaffinches Fringilla coelebs, including both songs and rain calls, are widespread across its distribution range, the boundaries between subspecies place formidable obstacles to the spread of vocal patterns. Aims To investigate the diversity of song types and song structure of rain calls in the contact zone between the Caucasian and Crimean subspecies of Chaffinches in the north-western Caucasus, as well as between the nominate and Caucasian subspecies in the northern Ciscaucasia (south of European Russia). Methods In total, the songs and rain calls of more than 300 males were recorded in 10 different locations in the Crimea, Caucasus, and Ciscaucasia. For comparison with more remote areas, we used our recording of Chaffinches from the Voronezh region and the city of Moscow. Results The song repertoires of Chaffinches in the Crimea and on the Abrau Peninsula (Black Sea basin) were very different despite being less than 100 km apart. In contrast, the repertoire of the Abrau population had much in common with the more distant (270–300 km) populations of the Caucasus and Ciscaucasia. The rain calls of Chaffinches on the Abrau had a unique two-syllable structure. On a sonogram, both of these types of sounds look very similar to the single-element calls of Caucasian and Crimean Chaffinches, but are significantly different in their frequency and temporal characteristics. Conclusion Zones of contact between Chaffinch subspecies appear to be a kind of filter that make it difficult to spread vocal patterns from the range of one subspecies to the range of another.

Anterior chamber angle classification in anterior segment optical coherence tomography images using hybrid attention based pyramidal convolutional network

As the main cause of irreversible visual impairment, angle-closure glaucoma (ACG) can be detected with anterior segment optical coherence tomography (AS–OCT). The automatic classification of anterior chamber angles (ACA) into closed angle, narrowed angle and open angle in the AS–OCT images is highly significant for understanding glaucoma progression. The traditional techniques for image classification usually rely on the extraction of handcrafted features from the images. Despite the popularity of deep learning methods in image classification, very few researches have been done to utilize them for the multi-class classification of AS–OCT images. In this work, a deep learning based algorithm is proposed for accurate ACA classification in AS–OCT images. The proposed method learns the distinguishable representations from numerous training AS–OCT images using the pyramidal convolution which contains multi-scale of kernels, where each scale includes several kinds of filters with changing depth and size. In this way, it can facilitate capturing the different levels of subtle visual cues that cannot be modeled by the handcrafted features. In addition, the skip connection has been adopted to concatenate the feature maps output at different levels to explore the correlation among them better. Moreover, the hybrid attention module including spatial attention and channel attention is introduced to emphasize important spatial and channel-wise information and reduce redundant information to increase the classification accuracy. We have evaluated classification performance of the proposed algorithm on 2636 ACA images from the Zhongshan Ophthalmic Center, Sun Yat-sen University in China, which is the only public ACG dataset in the world. The experimental results show that our algorithm can classify ACA as closed angle, narrowed angle and open angle effectively and it outperforms existing popular deep learning methods by providing higher specificity, sensitivity, accuracy and balanced accuracy.

Two Support Vector Machine Methods for Image Noise Filter

To solve the fatal limitation of SVMs based on the pre-known, two new image noise filter methods - Support Vector Machine based on self-learning machine (SLM-SVM) were presented, which is working better than many other non-linear filters, such as median filters and adaptive filters. A series of comparison and working parameters would be explained, performance of test showed these methods can dealing with the noise in a totally unknown image. And filter out more than 99% noise pixels from an image. In the same time, this kind of filter is still immature due to its long runtime (more than 2 second) and some error cases during testing, some recommendation and prediction were proposed.

A Recognition Method for Multi-Radial-Distance Event of Φ-OTDR System Based on CNN

This paper proposes a multi-radial-distance event classification method based on deep learning. To the best of our knowledge, this is the first time that the $\Phi $ -OTDR can tell how far the target event from the sensing fiber is through deep learning approach. The temporal-spatial data matrix collected by the system is filtered by three different band-pass filters to form RGB images as the input of the Inception_V3 network trained by ImageNet dataset. The passband of three band-pass filters is selected by searching the maximum Euclidean distance in the frequency domain. Three kinds of filters with different frequency bands enhance the effective features of data samples in advance. The simulated annealing (SA) algorithm is applied to search the maximum Euclidean distance. Field experiment includes five kinds of events with four different radial distances, where there are 17 subclasses in total, has been carried out. The classification results show that the classification accuracy reaches 86% and the method can tell both the event type and radial distance.

Compensation of Current Measurement Offset Error for Permanent Magnet Synchronous Machines

Thermal drift-caused current measurement offset error usually results in unfavorable torque ripples of fundamental frequency, and hence a compensation method for current offset error is proposed in this article, which is initially derived based on the nonsalient-pole machines and then extended to the salient-pole machines. By filtering the difference between the predicted currents from a simple nominal model and the measured currents, the offset error is directly estimated and then compensated with minimal effects on the current dynamics. It is proved that the estimation is accurate if the filter has unity gain at the frequency of the offset error. Therefore, the proposed method is free of the current regulator type and shows strong robustness against machine parameter deviations. It can also stably work even when the output voltage is saturated. Two kinds of filters are designed in the stationary reference frame, and the low-pass filter with low bandwidth is recommended for its easy implementation. Finally, the effectiveness of the proposed method is verified by simulations and experiments.