Regular Modes Research Articles

The Calculating Method of Thinning Pipes Ends before Rolling in the Reduction Mill

In this article it is discussed one of the main directions of improving the rolling tubes technology on a pipe-rolling plant with a continuous mill, in order to reduce the pipe-ends cut. A method for preliminary end sections thinning modes, calculating during rolling on a continuous mill, to compensate for wall subsequent thickening in the reduction mill, has been developed. Method distinctive feature is the calculation of end thickening volume, which must be reduced by a specified quantity when end sections rolled. The sequence of technological calculations is given. The results of pipe reduction computer simulation by regular rolling modes, and modes calculated by the proposed method, are represented The analysis of the simulation results showed the possibility of thickened ends length reducing of at least 10%.

Психологические особенности аудирования англоязычных видеоматериалов студентами технического вуза в режиме опережающей самостоятельной работы

Listening comprehension, as the most challenging receptive aspect of learning a foreign language at a technical university, is considered. It is noted that in addition to linguistic difficulties, students experience such psychological difficulties as a lack of recipient’s own perceptual experience, uncomfortable perception conditions, anxiety and fear of failure to perform this type of speech activity. It is shown that the perceptual activity of students, aimed at the auditory perception of English discourse, is naturally included in the most relevant students’ communicative competence. The study is aimed at considering psychological and pedagogical aspects in teaching ordinary listening comprehension without a video sequence and with the use of video materials. We reveal the advantages of using video materials that contribute to the creation of psychologically comfortable conditions for students in the educational process. Opinion analysis of first-year students of the St. Petersburg State University of Telecommunications on conducting listening comprehension in regular and flipped classroom modes is presented: it turns out that most students prefer to perform listening practice at home. We describe the audiovisual technology of advanced independent work on listening comprehension to professionally oriented video materials using the electronic resources VideoAnt, Mindmeister, LMS MOODLE. An advertising film of the computer company CISCO (USA) was used as video course basis, with its subject fully corresponding to the “Service” programme of St. Petersburg State University of Telecommunications.

Demand and Driver Supply Implications of Regular Public Transportation System for Policy Makers: A Case Study of Kandahar City, Afghanistan

Kandahar city of Afghanistan being one of the largest cities of the country does not have any regular system of public transportation. Unfortunately, at the moment the entire picture of the current services and future plans is unclear due to the lack of travel behavioral data including trip rate, travel time distribution, modal share and so on. More serious is that mechanism behind the behavior has not been figured out, so that no comprehensive transportation planning was established from theoretical basis. As the unprecedented study in Kandahar city, this paper attempted to carry out a travel survey with Revealed and Stated Preference (RP/SP) approach to understand travel behavior for the first time, by focusing on determinant factors of demand for regular public transportation modes and supply of drivers using discrete choice modelling approach. The results revealed that travel time and travel cost are among the most influential factors for forecasting the demand of public transport. Other socio-demographic factors such as gender, age, monthly income, and vehicle ownership are also demand determinant factors. Furthermore, consideration of women in all processes of planning and operating public transit is very essential. On the other hand, due to low income, higher working loads and some other job related factors, the drivers of paratransit system are not satisfied with their current jobs and have shown strong willingness to become bus drivers in future. Their willingness to change their jobs is effected by their personal income levels, availability of other income sources, education and some other social factors.

FINDING THE TEMPERATURE CONDUCTIVITY COEFFICIENT FROM THE SOLUTION OF THE DIRECT PROBLEM OF HEAT CONDUCTIVITY FOR A SEMI-LIMITED SOLID

The article concerns methods and formulas for the calculation of the coefficient of thermal conductivity of solid bodies using the known solutions of direct thermal conductivity tasks. The solution to the inverse problem of heat conductivity is based on the quite complicated methods including both hyperbolic functions and finite-difference methods. Under certain experimental conditions, the task is simplified at the regular thermal modes of 1, 2, or 3 types. Thus final formulas are simplified to algebraic equations. The simplification of the inverse problem of heat conductivity to algebraic equations is possible using other approaches. These methods are based on the analysis of the reference points, zero values of temperature distribution function, function inflection points, and its first and second derivatives. Here, we present formulas for the calculations of the temperature field on the assumption of the direct task solution for the half-bounded bar under the pulsed heating followed the re-definition of the boundary conditions. The regular thermal mode of the third family is name the mode at which the harmonic heating is set (repetitive) in time. At the set harmonic mode the law of fluctuation in the temperature of all points of body is known in time. The article describes three methods in which solutions are reduced to simple algebraic formulas when using the specified points on heating thermograms of test examples. These solutions allow algebraic deriving of simple relations for inverse problems of determination of thermophysical characteristics of solid bodies. The calculation formulas are given for the determination of the heat conductivity coefficient determination by three methods: by amplitude of temperature wave, a period of vibrations is a relative coefficient of heat exchange; by the change of phase of temperature wave; by a wave-length. The second method uses the values of two coordinates of the test sample in two different points where the equal temperature is reached at different points in time. The final solution of the equation is logarithmic. The analysis of known methods and techniques shows that experimental methods are oriented on the technical implementation and based on facilities of available equipment and instruments. Existing experimental techniques are based on specific constructions of measuring facilities. Simultaneously, there are well-studied methods of solution of thermal conductivity standard tasks set out in fundamental issues. The theoretical methods come from axioms, equations, and theoretical postulates, and they give the solution of inverse tasks of thermal conductivity. This work uses the solutions of direct tasks presented in the monograph by A. V. Lykov “The theory of heat conductivity”. These solutions have a good theoretical background and experts' credit. The boundary conditions of the problem are next: the half-bounded thin bar is given. The side surface of the bar has a thermal insulation. At the initial moment, the harmonic heat source acts on the bar in its section at some distance from its end. Heat exchange occurs between the environment and the end of the bar according to Newton's law. The initial (relative) temperature of the bar is accepted equal to zero. The heat exchange between the free end face of the bar and the environment is gone according to Newton's law.

Stellar Dynamos in the Transition Regime: Multiple Dynamo Modes and Antisolar Differential Rotation

Abstract Global and semi-global convective dynamo simulations of solar-like stars are known to show a transition from an antisolar (fast poles, slow equator) to solar-like (fast equator, slow poles) differential rotation (DR) for increasing rotation rate. The dynamo solutions in the latter regime can exhibit regular cyclic modes, whereas in the former one, only stationary or temporally irregular solutions have been obtained so far. In this paper we present a semi-global dynamo simulation in the transition region, exhibiting two coexisting dynamo modes, a cyclic and a stationary one, both being dynamically significant. We seek to understand how such a dynamo is driven by analyzing the large-scale flow properties (DR and meridional circulation) together with the turbulent transport coefficients obtained with the test-field method. Neither an αΩ dynamo wave nor an advection-dominated dynamo are able to explain the cycle period and the propagation direction of the mean magnetic field. Furthermore, we find that the α effect is comparable or even larger than the Ω effect in generating the toroidal magnetic field, and therefore, the dynamo seems to be of α 2Ω or α 2 type. We further find that the effective large-scale flows are significantly altered by turbulent pumping.

Reverse Task of Heat Conductivity for the Semilimited Bar

The article concerns methods and formulas for the calculation of the coefficient of thermal conductivity of solid bodies using the known solutions of direct thermal conductivity tasks. The solution to the inverse problem of heat conductivity is based on the quite complicated methods including both hyperbolic functions and finite-difference methods. Under certain experimental conditions, the task is simplified at the regular thermal modes of 1, 2, or 3 types. Thus final formulas are simplified to algebraic equations.
 The simplification of the inverse problem of heat conductivity to algebraic equations is possible using other approaches. These me­thods are based on the analysis of the reference points, zero values of temperature distribution function, function inflection points, and its first and second derivatives. Here, we present formulas for the calculations of the temperature field on the assumption of the direct task solution for the half-bounded bar under the pulsed heating followed the re-definition of the boundary conditions.
 The article describes two methods in which solutions are reduced to simple algebraic formulas when using the specified points on hea­ting thermograms of test examples. These solutions allow algebraic deriving of simple relations for inverse problems of determination of thermophysical characteristics of solid bodies. The calculation formulas are given for the determination of the heat conductivity coefficient determination by two methods: by value of temperature, coordinate, and two moments at which this temperature is reached.
 The second method uses the values of two coordinates of the test sample in two different points where the equal temperature is reached at different points in time. The final solution of the equation is logarithmic. The analysis of known methods and techniques shows that experimental methods are oriented on the technical implementation and based on facilities of available equipment and instruments.
 Existing experimental techniques are based on specific constructions of measuring facilities. Simultaneously, there are well-studied methods of solution of thermal conductivity standard tasks set out in fundamental issues. The theoretical methods come from axioms, equations, and theoretical postulates, and they give the solution of inverse tasks of thermal conductivity. This work uses the solutions of direct tasks presented in the monograph by A.V.Lykov “The theory of heat conductivity”. These solutions have a good theoretical background and experts’ credit.
 The boundary conditions of the problem are next: the half-bounded thin bar is given. The side surface of the bar has a thermal insulation. At the initial moment, the instant heat source acts on the bar in its section at some distance from its end. Heat exchange occurs between the environment and the end of the bar according to Newton’s law. The initial (relative) temperature of the bar is accepted equal to zero. The heat exchange between the free end face of the bar and the environment is gone according to Newton’s law.

TISSUE STRUCTURE CHANGES AS THE GROUND TO CHOOSE A METHOD OF ELECTRIC WELDING OF CHRONIC HEMORRHOIDS

Using of electric welding makes possible bloodless division of live tissues, reliable clamping of vessels. Due to this fact, the technology is successfully spreading through the surgical clinics. However, tissue structure changes, occurred as the result of current passage, are not studied sufficiently. Meanwhile, its knowledge is necessary for surgeons in order to understand the possibilities of technologies, indications and contraindications for its use. Objective of study: to investigate changes in the arterial wall up to 2.0 mm in diameter and venous wall up to 4.0 mm in diameter, adipose tissue and fascia as the result of use of basic modes of the apparatus Patonmed® EKVZ-300 for the purpose to determine their most effective application in the surgical treatment of chronic hemorrhoids. Material and methods. During the last 3 years surgical treatment of combined chronic hemorrhoids was performed on 58 patients, 32 males and 26 females at the age from 36 to 74 years. Surgical procedure was performed by means of main regular voltage modes, provided by Patonmed® EKVZ-300. In 58 patients 216 hemorrhoidal piles were found, including 32 of II degree, 143 of III degree and 41 of IV degree. Surgery consisted of hemorrhoidectomy beginning with mobilization of external piles which enabled to assess subcutaneous-submucosal blood flow in the transitional zone. At first, the zone of excision was outlined in order to avoid postsurgical anal stenosis. The perianal skin was cut by a scalpel up to the lower edge. The following stages of surgery were performed by means of welding. In the transitional zone and near the anal canal mobilization was performed by means of welding with modes of cutting (HL), coagulation (LL), automatic welding (DA) in different variants of power. Results and discussion. In case of high density of the superficial fascia varicose changed piles were isolated with HL-1 mode. All the varicose changed veins were mobilized in one block with completely controlled hemostasis. In case of significant destruction of superficial fascia, a grape-like varicose dilation of hemorrhoidal piles and their dense filling with blood the mode LL was used. Mobilization of one pile required 9-12 welding with HL-1 mode or 10-16 with LL-5 mode. Mobilization of one pile lasted 4.8±2.6 minutes and 7.3±3.8 minutes respectively. Near the edge of the transient zone for the purpose of mobilization only LL mode was used. Welding in the transient zone lasted 4,5±3,5 minutes. Welding of internal hemorrhoids was fully-fledged by using LL-5 mode in 93.1 % of cases, LL-4 – in 82.6 %, LL-3 – in 69 %. Mobilization of one pile took 11.4±4.6 minutes. In 26 cases when the diameter of a pile was up to 8.0 mm, undamaged serratus line and the absence of large dilation of veins in its projection, transmucous welding was applied by two-three time voltage supply. Welding was successful in case of LL-5 mode used in 50 % of observations, DA-3 – in 87.5 % DA-5 – in 87.5 %. Fixation by means of suturing as a part of surgery was used in case of prolapsed segment longer than 15.0 mm or more than 25.0 mm. As in case of internal hemorrhoids welding, the most effective were modes LL-5, DA-3 and DA-5. Wound edges were approximated by application of interrupted sutures or they were left untouched. Morphologic investigation showed coagulative changes in the walls of welded arteries and veins with the formation of homogeneous junction at the place of electrodes application. Outside of this area dystrophic changes of the vascular wall were observed not far than 1 mm aside. Conclusions. 1. To cut the skin hypoderm and highly dense superficial fascia the mode HL-1 is preferable. In case of significant destruction of the superficial fascia, a grape-like varicose dilation of hemorrhoidal piles and their dense filling with blood surgery on a dry field and good identification of all anatomic structures may be achieved by using of LL mode. 2. By using LL-5 mode well-controlled and bloodless mobilization of the external and the internal hemorrhoids of all sizes and localization was possible to perform, except the transient zone, where considering minimal thermal damage, the use of LL-3 mode is reasonable. 3. DA-3 mode appeared to be effective for transmucous welding of a hemorrhoidal pile of II degree, up to 8.0 mm in diameter, a pile without visible supplying vessels in its projection over the serratus line, and in case of fixation of a prolapsed segment of the anal and rectal mucosa up to 20.0 mm in length. 4. DA-5 mode makes it possible to perform transmucous welding of hemorrhoids of II-III stages, submucous coagulation with simultaneous fixation of a prolapsed segment of the anal and rectal mucosa more than 20.0 mm long.

A Study of the Operability of an RZhFA-6500 Reactor Consisting of an L-Shaped Filter Device of a Direct Current Traction Substation

Abstract—Two units of an RZhFA-6500 reactor were put into operation into a current return circuit of the Uglerod traction substation of the West Siberian Railroad in series connection with RBFA-U-6500/3250 reactor as a part of a resonant-aperiodic L-shaped filter device. Before assembling the new type reactor, its inductances were measured with the ammeter–voltmeter method under alternating current. The phase-shift angle between current and voltage drop on the RZhFA-6500 reactor was not controlled. To check the operability of the new of type reactor and analyze its efficiency, a series of experiments in the regular and emergency operation modes of the dc traction power supply system were conducted. An experiment using a forced short circuit without cessation of the motion of electric vehicle over the section was performed. Oscillograms at the catenary feeder and the circuit of traction current return were synchronously recorded upon disconnection of a high-speed switch. A comparative analysis of harmonic composition of the voltage drops on the reactors of two types was carried out. The amplitude–frequency responses of traction current for different operation modes of the Uglerod traction substation were plotted. The method for calculation of the RZhFA-6500 reactor inductance based on recorded oscillograms in regular and emergency operation modes of the traction power supply system was developed and tested. A universal formula for inductance calculation taking into account the phase-shift angle between the current and the voltage drop on the reactor when measurements by the ammeter–voltmeter method was derived.

Monte Carlo modeling of a X-ray tube for superficial radiotherapy for evaluating the beam quality and the depth-dose distribution

The purpose of this study was to evaluate the possibility of using GEANT4 modeling package in the problems of dosimetry and treatment planning of superficial radiotherapy on the apparatus “Roentgen TA-02”. Experimental measurements and calculation of half-value layer for beams in the regular operation modes, as well as depth dose distributions were carried out in accordance with the recommendations of American Association of Physicists in Medicine (AAPM). These parameters were compared with the results of the computer model of the x-ray tube. Comparison of partial half-value layer showed high efficiency of GEANT4 package in processing of physical processes associated with x-ray radiation and interaction with the matter. The data obtained during the work with the x-ray tube model are comparable both with the estimated results and published by other authors. The x-ray beams obtained in the simulation is comparable in quality with the real ones. The simulated and real beams coincide with the depth-dose distribution in the tissue equivalent medium with high accuracy.

Non-normality increases variance of gravity waves trapped in a tilted box

ABSTRACTWe study the prototype problem of internal gravity waves in a square domain tilted with respect to the gravity vector by an angle θ. Only for and a countable number of other angles regular normal modes exist, for all other angles wave attractors and singularities dominate the flow. We show that the linear operator of the governing PDE becomes non-normal for giving rise to non-modal transient growth. This growth depends on the underlying norm: for the variance norm significant growth rates can be found whereas for the energy norm, no growth is possible since, in contrast to shear flows for which the mean flow feeds the perturbations, there is no energy source. We continue by showing that the non-normality of the system matrix is increasing with θ and reaches a maximum for . Moreover, with increasing tilt angle the growth rate is increasing as can be expected from the increasing non-normality of the matrix. Our results imply that at least the most simple wave attractors can be seen as those initial flow fields that gain most of the variance during a given time period. We conclude that in a closed confinement with walls tilted with respect to gravity, internal wave variance can be maintained by transient growth of perturbations without a direct contribution of unstable normal modes.

Effect of annealing on photoluminescence and Raman scattering of Sb-doped ZnO epitaxial layers grown on a-Al2O3

ZnO thin films have been realized via monodoping antimony (Sb) acceptor by Molecular Beam Epitaxy on a-Al2O3 substrates. The influence of annealing on photoluminescence (PL) and micro-Raman spectra of ZnO:Sb layers was analyzed. PL spectra recorded at 6 K are dominated by two peaks: at around 3.31 eV and 3.35 eV. First one is assigned to free electrons to neutral acceptors (FA) transition and the second peak corresponds to donor bound exciton (D0X). In order to properly identify and analyze Raman modes, the room temperature Stokes Raman spectra were compared with the spectra of similar ZnO:As/Al2O3 structures. In addition to regular ZnO and Al2O3 modes, recorded ZnO:Sb Raman spectra contain 3 additional modes at around 509, 532 and 575 cm−1 that are associated with antimony doping. The intensity of doping-related bands decreases with increasing annealing temperature, which indicates the improvement of crystalline quality of the structure. The spectra also reveal the presence of compressive in-plane strain that decreases in value with increasing annealing temperature and is due to thermal residual stress, resulting from differences in thermal expansion coefficients of ZnO and Al2O3

Analysis of Various Approaches to Modeling of Dynamics of Lifting-Transport Vehicles

The results of analytical and numerical modeling of dynamic characteristics of linear and non-linear mathematical models of the “trolley-load” system of bridge and container cranes are presented. KiDyM software complex is used for numerical modeling, which, based on the use of the apparatus of structural matrices and the built-in computer algebra system, allows the construction of ordinary differential equations of motion of the class of systems under consideration at the analytical level. Recommendations on the possible use of the considered mathematical models of the “trolley-load” system in various regular and forced operation modes of bridge and container cranes are given on the basis of the analysis. The ratio of the results of calculations for various design models of regular and forced operation of the bridge crane has been established. The magnitude of the distribution of the maximum values of the dynamic characteristics of motion of the container crane has been designed by calculating the forced operation mode using various mathematical models.

Single-Station Location of Radio Emission Sources in the Decameter Wavelength Range Using a Wide-Aperture Direction Finder and a Chirp Ionosonde–Radio Direction Finder

We present the results of single-station location of radio emission sources on the mid-latitude Vasil’sursk—Rostov-on-Don path using a wide-aperture direction finder and a chirp ionosonde–radio direction finder. Methods for determining the arrival angles under conditions of multipath reception of radio signals are described. It is shown that when single- and double-hop propagation modes are separated by different direction-finding techniques, deviations of the arrival angles reach 5° in the azimuthal plane and up to 10◦ in the elevation plane, which is due to the traveling ionospheric disturbances. It is established that under conditions of a sporadic Es layer, the chirptransmitter azimuth with averaging over frequency and sounding sessions can be determined to an accuracy of 0.1°. When regular 1F and 2F propagation modes are used to estimate the chirptransmitter azimuth, the average errors are 0.5° and 1°–2°, respectively. An algorithm for solving the inverse problem, by which the coordinates of the radio emission sources can be determined from the arrival angles using both the IRI-2012 ionospheric prediction model and correction of the data from the vertical sounding station at the reception point, have been developed. It is shown that the average error in determining the range to radio emission sources is 13%.

PD53-04 DOUBLE-BLIND PROSPECTIVE RANDOMIZED CLINICAL TRIAL COMPARING REGULAR AND MOSES MODES OF HOLMIUM LASER LITHOTRIPSY: PRELIMINARY RESULTS

You have accessJournal of UrologyStone Disease: Surgical Therapy V1 Apr 2018PD53-04 DOUBLE-BLIND PROSPECTIVE RANDOMIZED CLINICAL TRIAL COMPARING REGULAR AND MOSES MODES OF HOLMIUM LASER LITHOTRIPSY: PRELIMINARY RESULTS Ahmed Ibrahim, Nader Fahmy, Serge Carrier, Mostafa Elhilali, and Sero Andonian Ahmed IbrahimAhmed Ibrahim More articles by this author , Nader FahmyNader Fahmy More articles by this author , Serge CarrierSerge Carrier More articles by this author , Mostafa ElhilaliMostafa Elhilali More articles by this author , and Sero AndonianSero Andonian More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2500AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Moses Technology has been shown to improve the fragmentation efficiency and reduced stone retropulsion both in in vivo and in vitro studies. However, there are no randomized trials evaluating effectiveness of this new technology during laser lithotripsy. Therefore, the objective was to compare Regular and Moses modes of holmium laser lithotripsy in terms of stone fragmentation efficiency and perioperative complications. METHODS After obtaining ethics approval, a prospective double-blind randomized trial was conducted for patients undergoing holmium laser lithotripsy. Patients were randomly assigned to have holmium laser lithotripsy with either Regular or Moses modes. Both patients and surgeons were blinded to the laser mode. All procedures were performed by four experienced urologists. Lumenis 120W generator with 200 Moses D/F/L fibers were used for all cases. Demographic data, stone parameters, peri-operative complications and success rates were compared. The degree of stone retropulsion was graded on a Likert scale from zero (no retropulsion) to 3 (maximum retropulsion). RESULTS A total of 66 patients were included in the study (33 per each arm). Both groups were comparable in terms of age, and pre-operative stone size (1.7 vs. 1.6 cm, p>0.05). When compared with the Regular mode, Moses Technology was associated with significantly lower fragmentation time (23.4 vs. 17.5 min, p<0.05) and total procedural time (53 vs. 42.1 min, p<0.05). However, there were no significant differences in terms of lasing time (6.5 vs. 7.1 min, p>0.05) and total energy applied to the stones (10.8 vs. 11.5 KJ, p>0.05). When compared between Regular and Moses modes, Moses technology was associated with significantly less retropulsion (mean grade was 1 vs. 0.4, p<0.05). There was no significant difference between both modes in terms of intra-operative complications (12.1 % vs. 3%, p>0.05). Only one case from Moses group had a small ureteral perforation requiring prolonged indwelling ureteral stenting. The success rate at the end of 1 month was comparable between both groups (90.1 vs. 87.9 %, p> 0.05). CONCLUSIONS Moses technology is associated with significantly lower fragmentation and procedural times. The reduced fragmentation time could be explained by the significantly lower reropulsion of the stones during laser lithotripsy; thus improving stone fragmentation efficiency. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e1047 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Ahmed Ibrahim More articles by this author Nader Fahmy More articles by this author Serge Carrier More articles by this author Mostafa Elhilali More articles by this author Sero Andonian More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Dynamic modes in a network of five oscillators with inhibitory all-to-all pulse coupling.

The dynamic modes of five almost identical oscillators with pulsatile inhibitory coupling with time delay have been studied theoretically. The models of the Belousov-Zhabotinsky reaction and phase oscillators with all-to-all coupling have been considered. In the parametric plane Cinh-τ, where Cinh is the coupling strength and τ is the time delay between a spike in one oscillator and pulsed perturbations of all other oscillators, three main regimes have been found: regular modes, when each oscillator gives only one spike during the global period T, C (complex) modes, when the number of pulses of different oscillators is different, and OS (oscillations-suppression) modes, when at least one oscillator is suppressed. The regular modes consist of several cluster modes and are found at relatively small Cinh. The C and OS modes observed at larger Cinh intertwine in the Cinh-τ plane. In a relatively narrow range of Cinh, the dynamics of the C modes are very sensitive to small changes in Cinh and τ, as well as to the initial conditions, which are the characteristic features of the chaos. On the other hand, the dynamics of the C modes are periodic (but with different periods) and well reproducible. The number of different C modes is enormously large. At still larger Cinh, the C modes lose sensitivity to small changes in the parameters and finally vanish, while the OS modes survive.

Analysis and Scheduling in a 5G Heterogeneous Content Delivery Network

Caching popular multimedia content constitutes a promising solution to mitigate the congestion in the ultimate potential for 5G networks. Moreover, a three-tier heterogeneous network, where device-to-device pairs, small cells, and macro base stations (BSs) are included, is suggested in 5G wireless networks. In addition, local caching of popular multimedia content for small-cell base stations (SBSs) and user equipment has been considered to decrease the BS transmission cost without requiring high capacity backhaul or access to the core network. Thus, in this paper, we first analyze the numerous relevant performances in this three-tier content delivery network. For the independent Poisson point process and uniform distribution, where there are two regular different SBS assumption modes, we first provide theoretical analysis of the hitting probability in this heterogeneous network in different user request transmission modes based on a stochastic geometry theory. Then, we further propose a novel resource selection and scheduling algorithm satisfying the signal-to-interference-plus-noise ratio and signal-to-interference ratio criteria and the optimal transmission link selections and scheduling strategy for the three-tier heterogeneous network in order to reasonably allocate restricted resources. Finally, the numerical results reveal that the theoretical results are in agreement with the simulation results of the Zipf-distribution caching scheme. Meanwhile, the proposed algorithm performs well compared with the theoretical limit and an increase in the state of the art.

НЕВЕРБАЛЬНІ ЗАСОБИ РЕПРЕЗЕНТАЦІЇ НАУКОВИХ НАРАТИВІВ

The considerations of scientific prestige, global competition among scientists, the speed and dynamics of modern life have led to the modifications in scientific discourse. Currently, scientists pay even more attention not only to the content of a message, but also to its form. The esthetic mode and narrativization have become the features of modern Anglo-American scientific discourse. The article deals with the narratives in the language of science through the prism of polycode nature of academic discourse. Various non-verbal research narratives are represented via book covers, pictures, images, graphs, diagrams and so on. The main characteristics of the research narrative, such as descriptive instruments, narrative intentionality, actionality, understandability, accessibility, creativity, logic, intrigue, esthetical mode were extensively illustrated with non-verbal narrative fragments found in scientific discourse. Narrative discourse stands out due to its eventfulness. We have paid special attention to the structural characteristics of the change of state, or condition, considering it as the main narrative feature. The action has been also considered in terms of singularity, fractality and intentionality. The action, together with the esthetical mode make the narrative scientific discourse stand out from the regular modes of research genres. The more narrative features we observe, the more evident is the narrative nature of a scientific discourse fragment. The language of science in the modern world is becoming more and more polycodal. Our research proves the polycode nature of narration in scientific discourse.

Interplay Between Dissipation and Modal Truncation in Ball-Beam Impact

We study a ball-beam impact in detail; and in particular, we study the interplay between dissipation and modal truncation. With Hertzian contact between a solid ball and an Euler–Bernoulli beam model, we find using detailed numerical simulations that many (well above 60) modes are needed before convergence occurs; that contact dissipation (either viscous or hysteretic) has only a slight effect; and that contact location plays a significant role. However, and more interestingly, we find that as little as 2% modal damping speeds up convergence of the net interaction so that only about 25 modes are needed. We offer a qualitative explanation for this effect in terms of the many subimpacts that occur in the overall single macroscopic impact. In particular, we find that in cases where the overall interaction time is long enough to damp out high modes yet short enough to leave lower modes undissipated, modal truncation at about 25 modes gives good results. In contrast, if modal damping is absent so that higher mode vibrations persist throughout the interaction, final outcomes are less regular and many more modes are needed. The regime of impact interactions studied here occurs for reasonable parameter ranges, e.g., for a 3–4 cm steel ball dropped at speeds of 0.1–1.0 m/s on a meter-long steel beam of net mass 1 kg. We are unaware of any prior similarly detailed numerical study which clearly offers the one summarizing idea that we obtain here.

Dynamics of the lattice of magnetic nanodipoles with cubic anisotropy

The 5 × 5 square lattices of magnetic dipoles with cubic crystallographic anisotropy were investigated by the computer simulation method. The conditions for implementing the random orientation of lattice configurations, each of which are characterized by a certain response to the influence of an external magnetic pulse, as well as by the established regime of the oscillation of the total magnetic moment under the influence of an alternating field, are revealed. Regular vibration modes with a doubled frequency and quasi-periodic and chaotic modes are detected. The dependence of the system response on the parameters of the magnetic field pulse is studied.

Counting statistics of chaotic resonances at optical frequencies: Theory and experiments.

A deformed dielectric microcavity is used as an experimental platform for the analysis of the statistics of chaotic resonances, in the perspective of testing fractal Weyl laws at optical frequencies. In order to surmount the difficulties that arise from reading strongly overlapping spectra, we exploit the mixed nature of the phase space at hand, and only count the high-Q whispering-gallery modes (WGMs) directly. That enables us to draw statistical information on the more lossy chaotic resonances, coupled to the high-Q regular modes via dynamical tunneling. Three different models [classical, Random-Matrix-Theory (RMT) based, semiclassical] to interpret the experimental data are discussed. On the basis of least-squares analysis, theoretical estimates of Ehrenfest time, and independent measurements, we find that a semiclassically modified RMT-based expression best describes the experiment in all its realizations, particularly when the resonator is coupled to visible light, while RMT alone still works quite well in the infrared. In this work we reexamine and substantially extend the results of a short paper published earlier [L. Wang et al., Phys. Rev. E 93, 040201(R) (2016)2470-004510.1103/PhysRevE.93.040201].