Real Time Fault Location Using the Retardation Method

A new method for short circuit fault location is proposed based on instantaneous signal measurement and its derivatives, and is based on the retardation phenomena. The difference between the times in which a signal is registered in two detectors is used to locate the fault. Although a description of faults in terms of a lumped circuit is useful for elucidating the methods for detecting the fault. This description will not suffice to describe the fault signal propagation hence a distributed models is needed which is given in terms of the telegraph equations. Those equations are used to derive a transmission line transfer function, and an exact analytical description of the short circuit signal propagating in the transmission line is obtained. The analytical solution was verified both by numerical simulations and experimentally.

Do Leonardo Da Vinci’s Drawings, Room Acoustics And Radio Astronomy Have Anything In Common?

After introducing Leonardo da Vinci’s (LdV) predecessors in the field of light propagation research, his drawings on the topic of focussing light through a spherical mirror are analysed. The discovery of LdV is presented, according to which, at an infinitely distant source of rays, a small fragment of the canopy is enough to generate a focus, while the rest of the mirror forms caustics for which LdV did not indicate an application. An analytical description of the energy concentration in the focus and on the caustics is given, together with its reference to the geometric representation of the acoustic field in rooms. Using symmetry in the description of energy relations in acoustics and electromagnetism, the interference that occurs on the caustics produced by the acoustic and electromagnetic wave is discussed. It is explained why in the sound field in existing halls, instead of a whole caustic only its cusp is observed, which is perceived as a point-like sound focus. The size of the mirror aperture, shown graphically by LdV, is determined. How the development of receiving techniques increased the mirror aperture compared to the LdV estimate is also shown. The implementation of these improvements is presented via the example of the Arecibo and FAST radio telescopes.

Implementation and use of the Levenberg-Marquard algorithm in the problems of calibration of robotic manipulators

The well-known problem of calibration of an arbitrary robotic manipulator, which is formulated in the most general form, is considered. To solve the direct problem of kinematics, an alternative to the Denavit-Hartenberg method, a universal analytical description of the kinematic scheme, taking into account possible errors in the manufacture and assembly of robot parts, is proposed. At the same time, a universal description of the errors in the orientation of the axes of the articulated joints of the links is proposed. On the basis of such a description, the direct and inverse problem of kinematics of robots as spatial mechanisms can be solved, taking into account the distortions of dimensions, the position of the axes of the joints and the positions of the zeros of the angles of their rotation. The problem of calibration of manipulators is formulated as a problem of the least squares method. Analytical formulas of the objective function of the least squares method for solving the problem are obtained. Expressions for the gradient vector and the Hessian of the objective function for the direct algorithm, Newton-Gauss and Levenberg-Marquardt algorithms are obtained by analytical differentiation using a special computer algebra system KiDyM. The procedures in the C ++ language for calculating the elements of the gradient and hessian are automatically generated. On the example of a projected angular 6-degree robot-manipulator, the results of modeling the solution to the problem of its calibration, that is, determination of 36 unknown angular and linear errors, are presented. A comparison is made of the solution of the calibration problem for simulated 64 and 729 experiments, in which the generalized coordinates - the angles in the joints took the values ±90° and -90°, 0, +90°.

On modelling of thermodynamic interaction of particles suspended in two-dimensional medium

Analytical description of temperature distribution in a medium with foreign inclusions is difficult due to the complicated geometry of the problem, so asymptotic and numerical methods are usually used to model thermodynamic processes in heterogeneous media. To be convinced in convergence of these methods the authors consider model problem about two identical round particles in infinite planar medium with temperature gradient which is constant at infinity. Authors refine multipole expansion of the solution obtained earlier by continuing it up to higher powers of small parameter, that is nondimensional radius of thermodynamically interacting particles. Numerical approach to the problem using ANSYS software is described; in particular, appropriate choice of approximate boundary conditions is discussed. Authors ascertain that replacement of infinite medium by finite-sized domain is important source of error in FEM. To find domain boundaries in multiple inclusions’ problem the authors develop “fictituous particle” method; according to it the cloud of particles far from the center of the cloud acts approximately as a single equivalent particle of greater size and so may be replaced by it. Basing on particular quantitative data the dependence of domain size that provides acceptable accuracy on thermal conductivities of medium and of particles is explored. Authors establish series of numerical experiments confirming convergence of multipole expansions method and FEM as well; proximity of their results is illustrated, too.

ANALISIS SELF EFFICACY PERAWAT BERDASARKAN DATA DEMOGRAFI DI TENGAH PANDEMI COVID-19

Abstrak COVID-19 telah menyebabkan krisis kesehatan global dengan meningkatnya jumlah orang yang terinfeksi dan meninggal setiap hari. Melihat banyaknya kasus dan gejala pasien covid-19 diatas memberi gambaran bahwa betapa banyaknya pasien dan resiko yang harus dihadapi oleh perawat, hal ini mempengarui psikologi perawat secara umum dan terkhusus mempengaruhi efficacy diri perawat tersebut. Tujuan penelitian ini adalah menganalisis self efficacy perawat berdasarkan data demografi ditengah pandemi covid-19. Penelitian ini bersifat deskripsi analitik dengan menggunakan pendekatan kuantitatif di RSUD Pare pada bulan april – september 2021. Populasi penelitian adalah semua perawat RS. Kabupaten Kediri. Jumlah sampel yang diambil 181 orang, Pengambilan data dilakukan dengan lembar kuesioner yang berisi tentang self efficay. Berdasarkan data tersebut diatas menunjukkan bahwa self efficacy sedang pada umur responden 26-35 tahun (35,4%), jenis kelamin terbanyak perempuan 73,5%, tingkat pendidikan D-3 Keperawatan 69,1%, lama kerja 2-10 tahun 38,7%. Sedangkan analisis self efficacy berdasarkan data demografi ditunjukkan dengan varibel umur memiliki nilai p = 0,001 r = 0,352, jenis kelamin nilai p = 0,045 r = 0,182, pendidikan nilai p=0,513 r =0,133, lama kerja nilai p = 0,007 r = 0,297. Umur, jenis kelamin,pendidikan, dan lama kerja memberikan dukungan yang baik pada self efficacay seseorang dalam melakukan kegiatan, termasuk kondisi perawat selama pandemi covid-19, mereka mengalami perubahan self efficacy selama merawat pasien dengan covid-19. Kata kunci : Self Efficacy, Demografi, Perawat, Covid-19 Abstract COVID-19 has caused a global health crisis with the number of people getting infected and dying every day. Seeing the number of cases and symptoms of COVID-19 patients above illustrates how many patients and the risks nurses must face, this affects the psychology of nurses in general and in particular affects the nurse's self-efficacy. The purpose of this study was to analyze the self-efficacy of nurses based on demographic data amid the covid-19 pandemic. This research is an analytical description using a quantitative approach at Pare Hospital in April – September 2021. The research population is all hospital nurses. Kediri Regency. The number of samples taken was 181 people. Data was collected using a questionnaire sheet containing self-efficacy. Based on the data above, it shows that self-efficacy is moderate at the age of the respondent 26-35 years (35.4%), the most gender is female 73.5%, education level D-3 Nursing 69.1%, length of work 2-10 years 38,7%. While the self-efficacy analysis based on demographic data is indicated by the age variable having p-value = 0.001 r = 0.352, gender p = 0.045 r = 0.182, education p-value = 0.513 r = 0.133, length of work p = 0.007 r = 0.297. Age, gender, education, and length of work provide good support for a person's self-efficacy in carrying out activities, including the condition of nurses during the covid-19 pandemic, they experience changes in self-efficacy while caring for patients with covid-19. Keywords : Self Efficacy, Demographics, Nurses, Covid-19

Orpheus’ Argonautica: Decoding the Real Voyage of the Argonauts

An analytical description of the Argonautic expedition through the ancient text “Orpheus Argonautica “with the assistance of Google Earth.

The role of public libraries within ensuring information security and formation of media literacy of personality

The purpose of the article is to determine the role of public libraries in ensuring the information securityof the individual and to establish the formation of its media education. Analyze the practice of teaching medialiteracy in libraries. The methodology consists of the application of general scientific methods of analysis and synthesis, generalization, and review-analytical description, which revealed the place and role of publiclibraries in the formation of personal media literacy and information security of the individual. The scientificnovelty is that the information security of the individual is considered in the context of media literacy andthrough the prism of library activities for the formation of media literacy of users. Conclusions. As a resultof the research, it is determined that - issues of information security of the individual are not considered atthe legislative level, to the appropriate extent, and the main attention is paid to the information security ofthe state. Information security of the individual is an interdisciplinary concept that is studied by scholarsin law, information and library affairs, journalism, computer technology, psychology, sociology, pedagogy,etc. Information security of the individual is an interdisciplinary concept that is studied by scholars in law,information and library affairs, journalism, computer technology, psychology, sociology, pedagogy, etc. It hasbeen proven that the information security of an individual depends on the level of his media literacy, ability tocritically evaluate information, identify unreliable – fake or ordered information that is misleading, to resistpropaganda and manipulation. Modern public libraries play an important role in shaping the media educationof citizens, in particular through their educational and educational activities. Media literacy training is heldon the basis of libraries. Libraries create information materials on this topic, select appropriate informationsources and resources, hold mass events on this topic.Keywords: informational security, media literacy, public library, information.

Method for analytical description and modeling of the working space of a manipulation robot

This paper reports a method, built in the form of a logic function, for describing the working spaces of manipulation robots analytically. A working space is defined as a work area or reachable area by a manipulation robot. An example of describing the working space of a manipulation robot with seven rotational degrees of mobility has been considered. Technological processes in robotic industries can be associated with the positioning of the grip, at the required points, in the predefined coordinates, or with the execution of the movement of a working body along the predefined trajectories, which can also be determined using the required points in the predefined coordinates. A necessary condition for a manipulation robot to execute a specified process is that all the required positioning points should be within a working space. To solve this task, a method is proposed that involves the analysis of the kinematic scheme of a manipulation robot in order to acquire a graphic image of the working space to identify boundary surfaces, as well as identify additional surfaces. The working space is limited by a set of boundary surfaces where additional surfaces are needed to highlight parts of the working space. Specifying each surface as a logic function, the working space is described piece by piece. Next, the resulting parts are combined with a logical expression, which is a disjunctive normal form of logic functions, which is an analytical description of the working space. The correspondence of the obtained analytical description to the original graphic image of working space is verified by simulating the disjunctive normal form of logic functions using MATLAB (USA).

Digital Echelons and Interfaces within Value Chains: End-to-End Marketing and Logistics Integration

The goals of real business in the context of the digital transformation of international logistics networks and marketing channels have necessitated the application of a scientifically based theoretical approach to the development of a formalized description acceptable for predictive planning based on leading indicators. In the context of globalization and interstate and regional economic unions, this will lead to achieving the maximum end-to-end integration of digital platforms. Based on the analysis, the article presents the integration of digital logistics and marketing approaches with the mathematical models of the ecosystem organization of economic relations. The features of the organization of economic relations between contractors involved in the execution of virtual transactions and the material movement of resources were analyzed. The researchers considered prerequisites for the analytical description of interconnections between the participants of digital platforms in cross border e-commerce. The authors’ approach is based on the idea of both a sales funnel in marketing and a conversion funnel in digital transformation. Considering the integration of logistics and marketing, authors offer the definition of business echelons as stages of the consumer value creation. The theoretical contribution of this article consists in constructing a mathematical description of business echelons along the entire value chain. The developed analytical description of business echelons is acceptable both for embedding a digital management support system into various software products, and for conducting in-depth analysis and finding optimal solutions.