49 research outputs found

    Risk-averse stochastic dynamic power dispatch based on deep reinforcement learning with risk-oriented Graph-Gan sampling

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    The increasing penetration of renewable energy sources (RES) brings volatile stochasticity, which significantly challenge the optimal dispatch of power systems. This paper aims at developing a cost-effective and robust policy for stochastic dynamic optimization of power systems, which improves the economy as well as avoiding the risk of high costs in some critical scenarios with small probability. However, it is hard for existing risk-neutral methods to incorporate risk measure since most samples are normal. For this regard, a novel risk-averse policy learning approach based on deep reinforcement learning with risk-oriented sampling is proposed. Firstly, a generative adversarial network (GAN) with graph convolutional neural network (GCN) is proposed to learn from historical data and achieve risk-oriented sampling. Specifically, system state is modelled as graph data and GCN is employed to capture the underlying correlation of the uncertainty corresponding to the system topology. Risk knowledge is the embedded to encourage more critical scenarios are sampled while aligning with historical data distributions. Secondly, a modified deep reinforcement learning (DRL) with risk-measure under soft actor critic framework is proposed to learn the optimal dispatch policy from sampling data. Compared with the traditional deep reinforcement learning which is risk-neutral, the proposed method is more robust and adaptable to uncertainties. Comparative simulations verify the effectiveness of the proposed method

    Epidemiological characteristics analysis of foodborne disease outbreaks caused by takeaway in China’s Mainland from 2010 to 2020

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    ObjectiveTo analyze the epidemiological characteristics of foodborne disease outbreaks caused by takeaway in China’s Mainland from 2010 to 2020, and put forward relevant regulatory suggestions.MethodsThrough the National Foodborne Disease Outbreak Monitoring System, the data of foodborne disease outbreaks caused by takeaway in China’s Mainland from 2010 to 2020 were collected and analyzed, and descriptive epidemiological characteristics were performed.ResultsA total of 549 foodborne disease outbreaks caused by takeaway were reported in China’s Mainland (except Tibet Autonomous Region) from 2010 to 2020, resulting in 9 285 illnesses and 2 deaths. The largest number of outbreaks and illnesses was in the third quarter, accounting for 41.53% and 44.58% of the total respectively. Except the unknown pathogenic factors, the number of outbreaks and illnesses caused by microbial pathogenic factors were the highest, accounting for 39.16% and 60.26% of the total respectively. Except the unknown suspected food, the number of outbreaks and illnesses caused by mixed food and multiple food were higher, accounting for 21.86% and 15.12% of the outbreaks respectively, and accounting for 20.58% and 13.10% of the number of illnesses respectively. Except the unknown food source, the top 3 food source were school canteens, collective dining delivery units/central kitchens and fast food restaurants, the number of outbreaks accounted for 20.04%, 15.66% and 15.48% respectively, and the number of illnesses accounted for 35.30%, 17.52% and 10.57% respectively. Except the multiple factors and unknown factors, the number of outbreaks caused by improper storage were the highest accounting for 8.74%, and the number of illnesses caused by improper processing accounted for 7.74%.ConclusionMicrobial growth and reproduction due to improper storage and processing is the major cause of foodborne disease outbreaks caused by takeaway. It is suggested that the food safety supervision and administration departments should strengthen the whole process supervision and management of takeaway, establish and ensure catering services strictly abide by the good hygiene operations according to food raw in materials, production, transportation, distribution and other aspects, so as to effectively prevent and control the occurrence foodborne diseases

    Электрохимическая прошивка микроотверстий в трубчатом ступенчатом концентраторе-волноводе медицинского назначения

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    A great attention has been recently paid to development of ultrasound technologies for treatment of blood vessels throughout the world. Authors of the paper have developed a new effective treatment method and ultrasound equipment that allow to carry out destruction of intravascular formations with simultaneous increase in elasticity of a vascular wall together with cardiologists from Belarusian Medical Academy of Postgraduate Education and Republican Scientific and Practical Center “Cardiology”. Advantages of the method are absence of necessity in surgical intervention, low probability of complications, low cost of treatment. The main component of the developed ultrasonic equipment is a tube-type stepped concentrator-waveguide having a spherical tip at a distal end with a single axial hole of 0.5 mm-diameter and three radial holes of 0.3 mmdiameter located at an angle of 120° relative to each other. The main effect for application of the concentratorwaveguide is achieved by ultrasonic vibromechanical action of a spherical tip on intravascular formation with subsequent removal of destruction products by their aspiration from a vascular bed. An additional effect is provided due to cavitation action on vascular formation and vessel walls by flow of fluid supplied via an internal cavity of the stepped concentratorwaveguide through the holes in the spherical tip. This contributes to a significant improvement in elastic properties of a vascular wall in atherosclerosis and diabetes. It is necessary to ensure high accuracy and quality of surfaces for the formed microholes in order to achieve maximum efficiency of the cavitation jet impact on intravascular formations and on the vascular wall. According to the analysis results on specific features of existing methods for small-diameter hole shaping, an electrochemical hole cutting method has been proposed which allows to obtain accurate micro-holes with a diameter of 0.3 mm and high surface quality in parts of small cross section and rigidity. The paper presents results of study on effect of electrochemical holes cutting parameters (voltage, concentration and consumption of electrolyte) on size and shape of the formed microholes. Main modes of electrochemical holes cutting process have been developed which allow to form micro-holes in a spherical tip of a tubular concentrator-waveguide with required accuracy, dimensions and shape.Развитию ультразвуковых технологий лечения сосудов в последнее время уделяют большое внимание во всем мире. Авторами статьи совместно с кардиологами из БелМАПО и РНПЦ «Кардиология» разработаны новый эффективный метод лечения и ультразвуковое оборудование, позволяющие выполнять разрушение внутрисосудистых образований с одновременным повышением эластичности сосудистой стенки. Преимуществами метода являются отсутствие оперативного вмешательства, низкая вероятность осложнений, небольшая стоимость лечения. Основной компонент разработанного ультразвукового оборудования – ступенчатый концентратор-волновод трубчатого типа, имеющий на дистальном конце сферический наконечник с одним осевым отверстием диаметром 0,5 мм и тремя радиальными отверстиями диаметрами 0,3 мм, расположенными под углом 120° друг относительно друга. Основной эффект применения концентратора-волновода достигается за счет ультразвукового вибромеханического воздействия сферическим наконечником на внутрисосудистое образование с последующим удалением продуктов разрушения путем их аспирации из сосудистого русла. Дополнительный эффект обеспечивается за счет кавитационного воздействия на сосудистое образование и стенки сосуда через отверстия в сферическом наконечнике потоками жидкости, подаваемой по внутренней полости ступенчатого концентратора-волновода, что способствует значительному улучшению эластических свойств сосудистой стенки при атеросклерозе и сахарном диабете. Для достижения максимальной эффективности воздействия кавитирующей струей на внутрисосудистые образования и на сосудистую стенку необходимо обеспечить высокие точность и качество поверхностей формируемых микроотверстий. По результатам анализа особенностей существующих методов формообразования отверстий малого диаметра предложен метод электрохимической прошивки, позволяющий получать точные микроотверстия диаметром 0,3 мм с высоким качеством поверхности на деталях малого сечения и жесткости. В статье представлены результаты исследования влияния параметров процесса электрохимической прошивки (напряжения, концентрации и расхода электролита) на размеры и форму получаемых микроотверстий. Разработаны основные режимы процесса электрохимической прошивки, позволяющие сформировать микроотверстия в сферическом наконечнике трубчатого концентратора-волновода требуемых точности, размеров и формы

    Пластическое деформирование и электрофизикохимическая обработка трубчатых медицинских концентраторов-волноводов

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    Ultrasonic methods for eliminating vascular obstruction are widespread throughout the world. The advantages of such methods are the absence of surgical intervention, a low probability of complications, and a low cost of treatment. Ultrasonic waveguide systems for the destruction of intravascular formations and elimination of vessel obstruction are made in the form of hollow or continuous long rods of constant and variable cross-section (concentrator waveguides). The development of  new methods of  treatment based on the use of  stepped  ultrasonic  waveguide systems of a tubular type is underway, allowing to supply fluids to the zone of dislocation of an intravascular formation. The presence of a hollow spherical tip with axial and lateral micro-holes in the distal part of such waveguide systems, designed to influence the resulting cavitation jet, both on the intravascular mass and on the affected area of the vascular wall, allows the vessel to be restored with a simultaneous increase in the elasticity of the vascular wall. Such a combined vibration and shock and cavitation effect is currently one of the most effective methods of treating intravascular formations. An analysis of the sizes, structures and materials for the manufacture of tubular concentrator waveguides shows that their shaping can be carried out by various methods: cold deformation, mechanical, hydroabrasive treatment, using welding (or related processes), electrolytic, and also combined processing methods. The existing processes for obtaining long products of small diameter, based on plastic methods, mechanical processing and physical and technical methods, have a number of disadvantages that do not allow the manufacture of tubular concentrator waveguides with the required characteristics. The paper presents the results of the analysis of literary sources, as well as the results of experimental studies, which have made it possible to substantiate the choice of methods for the step-by-step manufacture of tubular concentrator waveguides: obtaining a tubular stepped element by unrestricted drawing, obtaining a working tip by distributing and crimping, obtaining side holes in the working tip by electrochemical сutting.Ультразвуковые методы устранения непроходимости сосудов получили широкое распространение во всем мире. Преимущества – отсутствие оперативного вмешательства, низкая вероятность осложнений и стоимость лечения. Ультразвуковые волноводные системы для разрушения внутрисосудистых образований и устранения непроходимости сосуда изготавливаются в виде полых или сплошных длинномерных стержней постоянного и переменного сечений (концентраторов-волноводов). Ведутся разработки новых методик лечения, основанных на применении ступенчатых ультразвуковых волноводных систем трубчатого типа, позволяющих подавать жидкости в зону дислокации внутрисосудистого образования. Наличие в дистальной части таких волноводных систем полого сферического наконечника с осевым и боковыми микроотверстиями, предназначенными для воздействия образующейся кавитационной струей как на внутрисосудистое образование, так и на пораженный участок сосудистой стенки, позволяет восстанавливать проходимость сосуда с одновременным повышением эластичности сосудистой стенки. Такое комбинированное виброударное и кавитационное воздействие является в настоящее время одним из наиболее эффективных методов лечения внутрисосудистых образований. Анализ размеров, конструкций и материалов для изготовления трубчатых концентраторов-волноводов показывает, что их формообразование возможно проводить различными методами: холодного деформирования, механической, гидроабразивной обработки, с использованием сварочных (или родственных процессов), электролитических, а также комбинированных методов обработки. Существующие процессы получения длинномерных изделий малого диаметра, основанные на пластических методах, механической обработке и физико-технических методах, имеют ряд недостатков, не позволяющих изготавливать трубчатые концентраторы-волноводы с требуемыми характеристиками. В статье представлены результаты анализа литературных источников, а также выполненных экспериментальных исследований, которые позволили обосновать выбор методов поэтапного изготовления трубчатых концентраторов-волноводов: получение трубчатого ступенчатого элемента безоправочным волочением, получение рабочего наконечника раздачей и обжимом, получение боковых отверстий в рабочем наконечнике электрохимической прошивкой

    Пластическое формообразование наконечника концентратора-волновода для ультразвуковой эндоваскулярной абляции

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    One of the most effective methods of treating intravascular formations at present is the use of stepped ultrasonic waveguide systems of a tubular type (concentrators-waveguides) with a hollow spherical tip, the presence of which makesit possible to supply liquid media to the dislocation zone of an intravascular formation with the aim of additional cavitation effect and as efficiently as possible. destroy intravascular formations due to vibration impact. Based on the results of the analysis on the features of the existing shaping methods for obtaining a hollow spherical tip of the concentrator-waveguide, it is advisable to use methods of plastic deformation – expansion and crimping. The paper presents results of preliminary calculations, numerical modeling and experimental studies of tip shaping processes of the concentrator-waveguide by distribution and crimping. On the basis of the finite element method in the environment of the ABAQUS software package, modeling of the expansion and crimping of a pipe billet was carried out, which has made it possible to: evaluate the stress-strain state of the deformable conical section of the billet, the change in wall thickness during the forming process and calculate the length of the billet for the design of the conical section; to establish the patterns of the influence of geometric parameters on the power modes of the distribution process; to set the parameters of the modes of forming the tip of the concentrator-waveguide by the method of distribution and crimping, which ensure the formation of the required geometry. The obtained results of preliminary calculation, numerical modeling and experimental studies of tip shaping processes of the concentrator-waveguide by distribution and crimping have similar values, which confirms the correctness of using both the method of preliminary calculation and numerical modeling in the development of the technology for manufacturing the concentrator-waveguide.Одним из наиболее эффективных методов лечения внутрисосудистых образований в настоящее время является применение ступенчатых ультразвуковых волноводных систем трубчатого типа (концентраторов-волноводов) с полым сферическим наконечником. Его наличие обеспечивает возможность подачи жидких сред в зону дислокации внутрисосудистого образования с целью дополнительного кавитационного воздействия, а также максимально эффективное разрушение внутрисосудистых образований за счет виброударного воздействия. При существующих особенностях методов формообразования для получения полого сферического наконечника концентратора-волновода целесообразно использовать методы пластического деформирования – раздачу и обжим. В статье представлены результаты предварительного расчета, численного моделирования и экспериментальных исследований процессов формообразования наконечника концентратора-волновода раздачей и обжимом. На основе метода конечных элементов в среде программного комплекса ABAQUS выполнено моделирование операций раздачи и обжима трубной заготовки, позволившее: оценить напряженно-деформированное состояние деформируемого конического участка заготовки, изменение толщины стенки в процессе формоизменения и рассчитать длину заготовки для оформления конического участка; установить закономерности влияния геометрических параметров на силовые режимы процесса раздачи; установить параметры режимов формообразования наконечника концентратора-волновода методом раздачи и обжима, обеспечивающие формирование требуемой геометрии. Полученные результаты предварительного расчета, численного моделирования и экспериментальных исследований процессов формообразования наконечника концентратора-волновода раздачей и обжимом имеют схожие значения, что подтверждает корректность использования как метода предварительного расчета, так и численного моделирования при разработке технологии изготовления концентратора-волновода

    A SARS-CoV-2 protein interaction map reveals targets for drug repurposing

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    The novel coronavirus SARS-CoV-2, the causative agent of COVID-19 respiratory disease, has infected over 2.3 million people, killed over 160,000, and caused worldwide social and economic disruption1,2. There are currently no antiviral drugs with proven clinical efficacy, nor are there vaccines for its prevention, and these efforts are hampered by limited knowledge of the molecular details of SARS-CoV-2 infection. To address this, we cloned, tagged and expressed 26 of the 29 SARS-CoV-2 proteins in human cells and identified the human proteins physically associated with each using affinity-purification mass spectrometry (AP-MS), identifying 332 high-confidence SARS-CoV-2-human protein-protein interactions (PPIs). Among these, we identify 66 druggable human proteins or host factors targeted by 69 compounds (29 FDA-approved drugs, 12 drugs in clinical trials, and 28 preclinical compounds). Screening a subset of these in multiple viral assays identified two sets of pharmacological agents that displayed antiviral activity: inhibitors of mRNA translation and predicted regulators of the Sigma1 and Sigma2 receptors. Further studies of these host factor targeting agents, including their combination with drugs that directly target viral enzymes, could lead to a therapeutic regimen to treat COVID-19

    A Novel Approach to the Combination of Knowledge Flow with Organizational Learning Process

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    Knowledge is becoming one of the most important factors for organizations (especially knowledge intensive ones) to keep their predominance of high competencies. This paper proposes a new approach to bringing knowledge flow into knowledge management system (KMS), through which the organizational learning could be better supported. Knowledge flow is an effective assistant for knowledge acquisition, sharing, reposition and generation (the key functions of KMS) in an organization. According to the usual notion that organizational learning could be divided into two types, internal learning and external learning, this paper presents a way to combine knowledge flow with KMS in common knowledge-based organizations, and we basically focus on the combination between knowledge flow and four domains of internal learning: individuals learning, intra -functional, inter- functional and multilevel learning, through which we improve the organization’s structure and core competency in the changeful environment.The original publication is available at JAIST Press http://www.jaist.ac.jp/library/jaist-press/index.htmlIFSR 2005 : Proceedings of the First World Congress of the International Federation for Systems Research : The New Roles of Systems Sciences For a Knowledge-based Society : Nov. 14-17, 2137, Kobe, JapanSymposium 6, Session 6 : Vision of Knowledge Civilization Society and Knowledg

    Sufficient conditions for graphs with{P2,P5}-factors

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    For a graph G , a spanning subgraph F of G is called an { P 2 ,P 5 }-factor if every component of F is isomorphic to P 2 or P 5 , where P k denotes the path of order k . It was proved by Egawa and Furuya that if G satisfies 3 c 1 ( G − S )+2 c 3 ( G − S ) ≤ 4| S |+1 for all S ⊆ V ( G ), then G has a { P 2 ,P 5 }-factor, where c k ( G − S ) denotes the number of components of G − S with order k . By this result, we give some other sufficient conditions for a graph to have a { P 2 ,P 5 }-factor by various graphic parameters such as toughness, binding number, degree sums, etc. Moreover, we obtain some regular graphs and some K 1 ,r -free graphs having { P 2 ,P 5 }-factors

    Plastic Deformation and Electrophysicochemical Treatment of Tubular Medical Concentrator Waveguides

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    Ultrasonic methods for eliminating vascular obstruction are widespread throughout the world. The advantages of such methods are the absence of surgical intervention, a low probability of complications, and a low cost of treatment. Ultrasonic waveguide systems for the destruction of intravascular formations and elimination of vessel obstruction are made in the form of hollow or continuous long rods of constant and variable cross-section (concentrator waveguides). The development of  new methods of  treatment based on the use of  stepped  ultrasonic  waveguide systems of a tubular type is underway, allowing to supply fluids to the zone of dislocation of an intravascular formation. The presence of a hollow spherical tip with axial and lateral micro-holes in the distal part of such waveguide systems, designed to influence the resulting cavitation jet, both on the intravascular mass and on the affected area of the vascular wall, allows the vessel to be restored with a simultaneous increase in the elasticity of the vascular wall. Such a combined vibration and shock and cavitation effect is currently one of the most effective methods of treating intravascular formations. An analysis of the sizes, structures and materials for the manufacture of tubular concentrator waveguides shows that their shaping can be carried out by various methods: cold deformation, mechanical, hydroabrasive treatment, using welding (or related processes), electrolytic, and also combined processing methods. The existing processes for obtaining long products of small diameter, based on plastic methods, mechanical processing and physical and technical methods, have a number of disadvantages that do not allow the manufacture of tubular concentrator waveguides with the required characteristics. The paper presents the results of the analysis of literary sources, as well as the results of experimental studies, which have made it possible to substantiate the choice of methods for the step-by-step manufacture of tubular concentrator waveguides: obtaining a tubular stepped element by unrestricted drawing, obtaining a working tip by distributing and crimping, obtaining side holes in the working tip by electrochemical сutting

    Electrochemical Cutting of Micro-Holes in Tubular Stepped Concentrator-Waveguide for Medical Purposes

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    A great attention has been recently paid to development of ultrasound technologies for treatment of blood vessels throughout the world. Authors of the paper have developed a new effective treatment method and ultrasound equipment that allow to carry out destruction of intravascular formations with simultaneous increase in elasticity of a vascular wall together with cardiologists from Belarusian Medical Academy of Postgraduate Education and Republican Scientific and Practical Center “Cardiology”. Advantages of the method are absence of necessity in surgical intervention, low probability of complications, low cost of treatment. The main component of the developed ultrasonic equipment is a tube-type stepped concentrator-waveguide having a spherical tip at a distal end with a single axial hole of 0.5 mm-diameter and three radial holes of 0.3 mmdiameter located at an angle of 120° relative to each other. The main effect for application of the concentratorwaveguide is achieved by ultrasonic vibromechanical action of a spherical tip on intravascular formation with subsequent removal of destruction products by their aspiration from a vascular bed. An additional effect is provided due to cavitation action on vascular formation and vessel walls by flow of fluid supplied via an internal cavity of the stepped concentratorwaveguide through the holes in the spherical tip. This contributes to a significant improvement in elastic properties of a vascular wall in atherosclerosis and diabetes. It is necessary to ensure high accuracy and quality of surfaces for the formed microholes in order to achieve maximum efficiency of the cavitation jet impact on intravascular formations and on the vascular wall. According to the analysis results on specific features of existing methods for small-diameter hole shaping, an electrochemical hole cutting method has been proposed which allows to obtain accurate micro-holes with a diameter of 0.3 mm and high surface quality in parts of small cross section and rigidity. The paper presents results of study on effect of electrochemical holes cutting parameters (voltage, concentration and consumption of electrolyte) on size and shape of the formed microholes. Main modes of electrochemical holes cutting process have been developed which allow to form micro-holes in a spherical tip of a tubular concentrator-waveguide with required accuracy, dimensions and shape
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