1,811 research outputs found
Electromagnetic Energy for a Charged Kerr Black Hole in a Uniform Magnetic Field
With the Komar mass formula we calculate the electromagnetic energy for a
charged Kerr black hole in a uniform magnetic field. We find that the total
electromagnetic energy takes the minimum when the Kerr black hole possesses a
non-zero net charge where is the strength of the
magnetic field, is the angular momentum of the black hole, is a
dimensionless parameter determined by the spin of the black hole.Comment: 9 pages, 1 figur
Symmetry, singularities and integrability in complex dynamics III: approximate symmetries and invariants
The different natures of approximate symmetries and their corresponding first
integrals/invariants are delineated in the contexts of both Lie symmetries of
ordinary differential equations and Noether symmetries of the Action Integral.
Particular note is taken of the effect of taking higher orders of the
perturbation parameter. Approximate symmetries of approximate first
integrals/invariants and the problems of calculating them using the Lie method
are considered
АНАЛІЗ ПОКАЗНИКІВ НАЙБІЛЬШ РОЗПОВСЮДЖЕНИХ ЗАХВОРЮВАНЬ, ЩО ПЕРЕДАЮТЬСЯ СТАТЕВИМ ШЛЯХОМ, У ВІННИЦЬКІЙ ОБЛАСТІ
Purpose: to analyze the dynamics of the most widespread sexually transmitted diseases (STDs) indicators in Vinnytsia region within 2014–2018.
Materials and Methods. An epidemiological retrospective research of the summary and statistical documentation of the Vinnytsia Regional Clinical Dermatovenerologic Dispensary (according to the Report of the Therapeutic and Prophylactic Institution No. 20) was carried out using the data retrieval method for the five-year period starting from 2014 to 2018. The parameters of the most common STDs in the Vinnytsia region and the Ukraine wide (syphilis, gonorrhea, trichomoniasis, chlamidiosis, urogenital mycoplasmosis) were treated with the means of statistical processing, analysis and evaluation. Methods of research – epidemiological, medical and statistical.
Results. The analysis of the five most common STDs indicators in the Vinnytsia region throughout 2014–2018 showed that four of them (syphilis, gonorrhea, trichomoniasis, chlamidiosis) have been decreasing annually, except for urogenital mycoplasmosis, whose visibility in 2018 in comparison with 2014 base was (+) 0.9%. The same trend (to decrease) for the period researched is typical for all of the mentioned diseases in Ukraine: syphilis – (-) 30.2 %, gonorrhea – (-) 32.6 %, trichomoniasis – (-) 31.9 %, chlamidiosis – (-) 16.7 %, urogenital mycoplasmosis – (-) 19.9 %. The annual growth (according to the growth rate) of the regional indicators of specific diseases by gender and place of residence is proven but the incidence rate of trichomoniasis, which was constantly decreasing in all cohorts.
Conclusions. The most important reasons for the decrease in the incidence of STDs in Ukraine and in the Vinnytsia region for the period researched are the following: 1) the absence of registration of these diseases in: private clinics, the predominant treatment of patients is due to the avoidance of stigmatization, especially among the people of rural areas; specialists of other specialties (urologists, obstetrician-gynecologists, etc.) of public health institutions; 2) financial inaccessibility to expensive medicines.Мета: проаналізувати динаміку показників найбільш розповсюджених захворювань, що передаються статевим шляхом (ЗПСШ), у Вінницькій області за 2014–2018 рр.
Матеріали і методи. Проведено епідеміологічне ретроспективне дослідження підсумково-звітної статистичної документації Вінницького обласного клінічного шкірно-венерологічного диспансеру (за даними звіту лікувально-профілактичного закладу ф. № 20) з використанням методу викопіювання даних за п’ятирічний період 2014–2018 рр. Статистичній обробці, аналізу та оцінці підлягали показники найбільш розповсюджених ЗПСШ захворювань, що передаються статевим шляхом (сифіліс, гонорея, трихомоніаз, хламідіоз, урогенітальний мікоплазмоз), у Вінницькій області та по Україні. Методи дослідження – епідеміологічний, медико-статистичний.
Результати. Аналіз показників п’яти найбільш розповсюджених захворювань, що передаються статевим шляхом, у Вінницькій області за 2014–2018 рр. виявив, що чотири з них (сифіліс, гонорея, трихомоніаз, хламідіоз) щорічно знижувались, крім урогенітального мікоплазмозу, показник наочності якого у 2018 р. до базового 2014 р. склав (+) 0,9 %. Така ж тенденція (до зниження), за досліджуваний період, характерна для усіх вказаних захворювань по Україні: сифіліс – (-) 30,2 %, гонорея – (-) 32,6 %, трихомоніаз – (-) 31,9 %, хламідіоз – (-) 16,7 %, урогенітальний мікоплазмоз – (-) 19,9 %. Доведено річні темпи зростання регіональних показників виокремлених захворювань за статтю і місцем проживання, крім показника захворюваності на трихомоніаз, який постійно знижувався у всіх когортах.
Висновки. Найбільш вагомими причинами зниження показників розповсюдження захворювань, що передаються статевим шляхом, в Україні й Вінницькій області за досліджуваний період є: 1) відсутність реєстрації цих захворювань у: приватних клініках, переважне звертання хворих до яких пов’язано з причиною уникнення стигматизації, особливо жителів сільської місцевості; фахівців інших спеціальностей (урологи, акушер-гінекологи та ін.) державних закладів охорони здоров’я; 2) фінансова недоступність до дороговартісної фармакотерапії
Moving boulders in flash floods and estimating flow conditions using boulders in ancient deposits
Boulders moving in flash floods cause considerable damage and casualties. More and bigger boulders move in flash floods than predicted from published theory. The interpretation of flow conditions from the size of large particles within flash flood deposits has, until now, generally assumed that the velocity (or discharge) is unchanging in time (i.e. flow is steady), or changes instantaneously between periods of constant conditions. Standard practice is to apply theories developed for steady flow conditions to flash floods, which are however inherently very unsteady flows. This is likely to lead to overestimates of peak flow velocity (or discharge). Flash floods are characterised by extremely rapid variations in flow that generate significant transient forces in addition to the mean-flow drag. These transient forces, generated by rapid velocity changes, are generally ignored in published theories, but they are briefly so large that they could initiate the motion of boulders. This paper develops a theory for the initiation of boulder movement due to the additional impulsive force generated by unsteady flow, and discusses the implications. Keywords
Methodical manual on the implementation of the course project on discipline "Designing of machine-building industries" for students of all forms of study Direction of preparation 131 "Applied mechanics"
Electromagnetic properties of non-Dirac particles with rest spin 1/2
We resolve a number of questions related to an analytic description of
electromagnetic form factors of non-Dirac particles with the rest spin 1/2. We
find the general structure of a matrix antisymmetric tensor operator. We obtain
two recurrence relations for matrix elements of finite transformations of the
proper Lorentz group and explicit formulas for a certain set of such elements.
Within the theory of fields with double symmetry, we discuss writing the
components of wave vectors of particles in the form of infinite continued
fractions. We show that for (GeV/c), where is
the transferred momentum squared, electromagnetic form factors that decrease as
increases and are close to those experimentally observed in the proton
can be obtained without explicitly introducing an internal particle structure.Comment: 18 pages, 2 figure
URBAN TRAFFIC FLOW ANALYSIS BASED ON DEEP LEARNING CAR DETECTION FROM CCTV IMAGE SERIES
Traffic flow analysis is fundamental for urban planning and management of road traffic infrastructure. Automatic number plate recognition (ANPR) systems are conventional methods for vehicle detection and travel times estimation. However, such systems are specifically focused on car plates, providing a limited extent of road users. The advance of open-source deep learning convolutional neural networks (CNN) in combination with freely-available closed-circuit television (CCTV) datasets have offered the opportunities for detection and classification of various road users. The research, presented here, aims to analyse traffic flow patterns through fine-tuning pre-trained CNN models on domain-specific low quality imagery, as captured in various weather conditions and seasons of the year 2018. Such imagery is collected from the North East Combined Authority (NECA) Travel and Transport Data, Newcastle upon Tyne, UK. Results show that the fine-tuned MobileNet model with 98.2 % precision, 58.5 % recall and 73.4 % harmonic mean could potentially be used for a real time traffic monitoring application with big data, due to its fast performance. Compared to MobileNet, the fine-tuned Faster region proposal R-CNN model, providing a better harmonic mean (80.4 %), recall (68.8 %) and more accurate estimations of car units, could be used for traffic analysis applications that demand higher accuracy than speed. This research ultimately exploits machine learning alogrithms for a wider understanding of traffic congestion and disruption under social events and extreme weather conditions
Proof of the Thin Sandwich Conjecture
We prove that the Thin Sandwich Conjecture in general relativity is valid,
provided that the data satisfy certain geometric
conditions. These conditions define an open set in the class of possible data,
but are not generically satisfied. The implications for the ``superspace''
picture of the Einstein evolution equations are discussed.Comment: 8 page
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