433 research outputs found

    Прогнозирование остаточного ресурса колёсных пар вагонов метрополитена «Русич» моделей 81-740/741

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    A modern approach to determining the useful life of components and parts of rolling stock allows not only to estimate the pre-failure state of an object, but also to predict its useful life.The objective of the study is to predict the mileage of wheelsets of modern electric trains of the «Rusich» series based on the use of statistical data and assessment of the residual life.The study used real data recorded during maintenance and repair of electric trains.The proposed approach allows getting a vivid presentation of the equipment wear rate, since it is based on the use of the measured parameters of the object. The analysis of these values makes it possible to determine the processes occurring in the product. When using large samples, it becomes possible to approximate the obtained numerical values and make a forecast of the technical condition with greater reliability.The task of predicting the residual life is quite complicated and must be solved separately for each type of equipment. That is why the generally accepted world practices are associated with preventive maintenance and repair system, while modern automated digital systems for technical diagnostics (including on-board and built-in ones) make it possible to partially switch to technical maintenance and repair considering the actual technical condition of the rolling stock.Современный подход к определению ресурса узлов и деталей подвижного состава позволяет не только оценивать предотказное состояние объекта, но и прогнозировать его ресурс.Целью исследования является прогнозирование величины пробега колёсных пар современных электропоездов модели «Русич» на основе использования статистических данных и определения остаточного ресурса.При проведении исследования использованы реальные данные, фиксируемые при обслуживании и ремонте электропоездов.Предложенный подход позволяет получить наглядное представление о скорости износа оборудования, так как он основан на использовании измеренных параметров объекта.Проведение анализа указанных величин даёт возможность определить процессы, протекающие в изделии. При использовании больших выборок появляется возможность провести аппроксимацию полученных числовых значений и произвести прогноз технического состояния с бóльшей достоверностью.Задача прогнозирования остаточного ресурса является достаточно сложной и должна решаться отдельно для каждого вида оборудования. Именно поэтому общепринятой мировой практикой является планово-предупредительная система технического обслуживания и ремонта. Но современные автоматизированные цифровые системы технического диагностирования (включая бортовые и встроенные) позволяют частично перейти на техническое обслуживание и ремонт с учётом фактического технического состояния подвижного состава

    Математические методы проверки достоверности данных о надёжности локомотивов, их эксплуатации и техническом обслуживании

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    The objective of the article is to describe the method proposed by the authors and intended for validity check of initial data for managing reliability of locomotives and the entire locomotive facilities. It is shown that probabilistic-statistical methods which constitute the basis of Edward Deming’s theory of enterprise variability allowing to control the quality of enterprises’ products, including their reliability.The averaged statistical data used in practices of railway transport and its locomotive economy are not homogeneous, representing what is called in popular publications «average temperature of hospital patients». The homogeneity of data is determined by their unimodality, i.e., the presence of a single process in the sample. Unsuccessful sampling leads to its bimodality and even multimodality.The research method proposed in the article is check for unimodality of the initial data based on the consequence of the law of large numbers, according to which, with an increase in the number of data, homogeneous samples tend to one of the laws of distribution of random variable: to normal, exponential, lognormal or other known law. Therefore, and since any unimodal sample must meet a goodness-of-fit test, the article proposes to apply Pearson’s chisquare test (χ2). The unimodality of the data is suggested to be estimated through the probability of compliance with the chosen law of distribution of a random variable considering the probability of more than 0,3 (30 %) to be sufficient.Using the example of locomotive operation data and on-board microprocessor systems data, data are shown that cannot really be unimodal, as well as the data that require changing the sampling rules to achieve unimodality. For example, when considering the average daily runs of locomotives by series at specific home depots with participation in one type of traffi (main traffi export, or shunting operations), their unimodality is achieved. An attempt to enlarge the data (to consider several series, several polygons, etc.) results in loss of unimodality.The article considers the unimodality of data of MSU-TP on-board microprocessor control systems for diesel locomotives of 2TE116U series. The expected operating time for the positions of the driver’s controller turned out to be multimodal data. Surprisingly, the current of the traction motors turned out to be unimodal, regardless of the driving position of the driver’s controller.Целью статьи является описание предлагаемого авторами метода контроля достоверности исходных данных для управления надёжностью локомотивов и локомотивным хозяйством в целом. Показано, что вероятностно-статистические методы являются основой теории вариабельности предприятия Эдварда Деминга, позволяющей управлять качеством продукции предприятий, включая их надёжность. В практике железнодорожного транспорта и локомотивного комплекса используемые среднестатистические данные на практике не являются однородными, что в популярных изданиях принято называть «средней температурой по больнице». Однородность данных определяется их унимодальностью, т.е. наличием в выборке одного процесса. Неудачное формирование выборки приводит к её бимодальности и даже мультимодальности.Методом исследования, предложенным в статье, является проверка на унимодальность исходных данных на основании следствия закона больших чисел, согласно которому при увеличении числа данных однородные выборки стремятся к одному из законов распределения случайной величины: нормальному, экспоненциальному, логнормальному или другому известному закону. Следовательно, любая унимодальная выборка должна соответствовать критерию согласия, в качестве которого в статье предлагается использовать критерий Пирсона («хи-квадрат», χ2). Унимодальность данных предлагается оценивать через вероятность соответствия выбранному для рассмотрения закону распределения случайной величины, считая достаточной вероятность более 0,3 (30 %).На примере данных эксплуатации локомотивов и данных бортовых микропроцессорных систем показаны данные, которые действительно не могут быть унимодальными, и указано на наличие данных, требующих изменения правил формирования выборки для достижения унимодальности. Например, при рассмотрении среднесуточных пробегов локомотивов по сериям по конкретным депо приписки при участии в одном виде движения (магистральное движение, вывозная или маневровая работа) достигается их унимодальность. Попытка укрупнить данные (взять несколько серий, несколько полигонов и др.) приводит к потере унимодальности.В статье рассмотрена унимодальность данных бортовых микропроцессорных систем управления МСУ-ТП тепловозов серии 2ТЭ116У. Ожидаемое время работы по позициям контроллёра машиниста оказалось относящимся к мультимодальным данным. Неожиданно унимодальным оказался ток тяговых электродвигателей независимо от ходовой позиции контроллера машиниста

    Whole-body mathematical model for simulating intracranial pressure dynamics

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    A whole-body mathematical model (10) for simulating intracranial pressure dynamics. In one embodiment, model (10) includes 17 interacting compartments, of which nine lie entirely outside of intracranial vault (14). Compartments (F) and (T) are defined to distinguish ventricular from extraventricular CSF. The vasculature of the intracranial system within cranial vault (14) is also subdivided into five compartments (A, C, P, V, and S, respectively) representing the intracranial arteries, capillaries, choroid plexus, veins, and venous sinus. The body's extracranial systemic vasculature is divided into six compartments (I, J, O, Z, D, and X, respectively) representing the arteries, capillaries, and veins of the central body and the lower body. Compartments (G) and (B) include tissue and the associated interstitial fluid in the intracranial and lower regions. Compartment (Y) is a composite involving the tissues, organs, and pulmonary circulation of the central body and compartment (M) represents the external environment

    Impacts of Conditionalities on Cash Transfer Beneficiaries in Osun State, Nigeria

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    The study examined the conditionalities of the cash transfer programme in Osun state, Nigeria. It examined the level of compliance of the beneficiaries of the programme and investigated the impacts of conditionalities of the cash transfer programme. A descriptive research design was adopted for the study and a sample size of 240 respondents was involved. Twenty-four communities were purposively selected for the study in Osun State. Ten recipients of the cash transfer programme were selected from each of the 24 communities using a simple random sampling technique. A research instrument was used for data collection known as the ‘Beneficiaries’ Questionnaire on Impacts of Conditionalities on Cash Transfer programme in Osun State’. Data collected were subjected to percentage analysis. Findings showed that the majority of the programme’s beneficiaries complied with the requirements or conditions attached to it. The findings of the study equally showed that the conditional cash transfer programme has changed the orientation of the beneficiaries on regular visitation to maternity centres. The study therefore concluded that for any poverty alleviation programme to be successful in Nigeria, especially in Osun state, conditionalities must be attached and beneficiaries should be encouraged to comply

    Направления повышения эффективности эксплуатации локомотивов

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    The article contains the analysis of statistics of locomotives’ operation and define main opportunities to increase its efficiency. The main objective of the study is to reveal factors influencing the increase in reliability of locomotives.Data of the sample of 40 locomotives of main series operated in Russia for the period of 400–500 days are used, which ensures accuracy of results obtained. The method of the study is mainly statistical processing of data. Besides commonly statistically analyzed positions like «in operation» and «faulty» new positions «at the head of the train» (effective work) and some other are considered. The coefficient of useful (effective) work is introduced. As a result, it is proved that feasible level of value-added use of locomotive up to 75 % of total time versus 49 % nowadays is possible. It is shown that reduction of time and cost of technical maintenance and repair of locomotives (TMR) is an important opportunity to increase efficiency of locomotives’ operation. Besides, it has been proved that one of the reasons of over-downtime of locomotives under repair is a significant volume of violations of operating modes, which is also confirmed by statistical data used in previous publications.В статье выполнен анализ статистики эксплуатации локомотивов и определены основные направления повышения эффективности тяги поездов. Основная цель исследования – выявление факторов повышения надёжности локомотивов.При этом использованы данные выборки по 40 локомотивам всех основных серий, эксплуатируемых в России, за 400–500 дней эксплуатации, что гарантирует достоверность полученных результатов. Метод исследования – статистическая обработка данных. При этом в дополнение к общепринятым состояниям «исправное» и «неисправное» рассмотрены новые «в голове поезда» (полезная работа) и ряд других. Введён коэффициент полезной работы. В результате доказан реально возможный уровень полезного использования локомотива до 75 % от общего времени против 49 % в настоящее время. Показано, что сокращение времени и стоимости технического обслуживания и ремонта локомотивов (ТОиР) является важным направлением повышения эффективности эксплуатации локомотивов. При этом ранее было показано, что одна из причин перепростоя локомотивов на ремонте – это существенный объём нарушений режимов эксплуатации, что было подтверждено статистическими данными

    МОДЕЛЬ УПРАВЛЕНИЯ РИСКАМИ ОТКАЗОВ ЛОКОМОТИВОВ

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    The article suggests methods of implementation of risk management for the tasks of increasing of locomotives’ reliability. The proposed key approaches are based on the methodology of Heinrich’s pyramid, correlation analysis and probability theory. This approach, followed by appropriate mathematical apparatus, leads to three circuit model comprising reliability management through accident management, problem management and service quality management. The authors cite the example of continuing implementation of automatic reliability control system with regard to service and based on described model.В статье предложена методика реализации подходов риск- менеджмента для решения задач, направленных на повышение надёжности локомотивов. Основу действий определяет методология пирамид Гейнриха с использованием корреляционного анализа и теории вероятности. В числе моделируемых механизмов контуры управления надёжностью и уровнем сервиса. Описан сопутствующий строящейся модели математический аппарат.

    Is automatic imitation a specialized form of stimulus–response compatibility? Dissociating imitative and spatial compatibilities

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    In recent years research on automatic imitation has received considerable attention because it represents an experimental platform for investigating a number of inter-related theories suggesting that the perception of action automatically activates corresponding motor programs. A key debate within this research centers on whether automatic imitation is any different than other long-term S-R associations, such as spatial stimulus-response compatibility. One approach to resolving this issue is to examine whether automatic imitation shows similar response characteristics as other classes of stimulus-response compatibility. This hypothesis was tested by comparing imitative and spatial compatibility effects with a two alternative forced-choice stimulus-response compatibility paradigm and two tasks: one that involved selecting a response to the stimulus (S-R) and one that involved selecting a response to the opposite stimulus (OS-R), i.e., the one not presented. The stimulus for both tasks was a left or right hand with either the index or middle finger tapping down. Speeded responses were performed with the index or middle finger of the right hand in response to the finger identity or the left-right spatial position of the fingers. Based on previous research and a connectionist model, we predicted standard compatibility effects for both spatial and imitative compatibility in the S-R task, and a reverse compatibility effect for spatial compatibility but not for imitative compatibility in the OS-R task. The results from the mean response times, mean percentage of errors, and response time distributions all converged to support these predictions. A second noteworthy result was that the recoding of the finger identity in the OS-R task required significantly more time than the recoding of the left-right spatial position, but the encoding time for the two stimuli in the S-R task was equivalent. In sum, this evidence suggests that the processing of spatial and imitative compatibility is dissociable with regard to two different processes in dual processing models of stimulus-response compatibility

    Detection of C3_{3} in Diffuse Interstellar Clouds

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    The smallest polyatomic carbon chain, C3_{3}, has been identified in interstellar clouds (Av_{v}\sim1 mag) towards ζ\zeta Ophiuchi, 20 Aquilae, and ζ\zeta Persei by detection of the origin band in its A1ΠuX1Σg+A^{1}\Pi_{u}-X^{1}\Sigma^{+}_{g} electronic transition, near 4052\AA. Individual rotational lines were resolved up to JJ=30 enabling the rotational level column densities and temperature distributions to be determined. The inferred limits for the total column densities (\sim1 to 2×1012\times10^{12} cm2^{-2}) offer a strong incentive to laboratory and astrophysical searches for the longer carbon chains. Concurrent searches for C2+_2^{+}, C2_2^{-} and C3_3^{-} were negative but provide sensitive estimates for their maximum column densities.Comment: 14 pages, 5 figures, 3 tables. To appear in the Astrophysical Journa

    Alignment to the Actions of a Robot

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    Alignment is a phenomenon observed in human conversation: Dialog partners’ behavior converges in many respects. Such alignment has been proposed to be automatic and the basis for communicating successfully. Recent research on human–computer dialog promotes a mediated communicative design account of alignment according to which the extent of alignment is influenced by interlocutors’ beliefs about each other. Our work aims at adding to these findings in two ways. (a) Our work investigates alignment of manual actions, instead of lexical choice. (b) Participants interact with the iCub humanoid robot, instead of an artificial computer dialog system. Our results confirm that alignment also takes place in the domain of actions. We were not able to replicate the results of the original study in general in this setting, but in accordance with its findings, participants with a high questionnaire score for emotional stability and participants who are familiar with robots align their actions more to a robot they believe to be basic than to one they believe to be advanced. Regarding alignment over the course of an interaction, the extent of alignment seems to remain constant, when participants believe the robot to be advanced, but it increases over time, when participants believe the robot to be a basic version
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