SOME DEFINITIONS FOR CONVOLUTIONS AND THE CONVOLUTIONS FOR THE FOURIER TRANSFORMS WITH GEOMETRIC VARIABLES

Joint Research on Environmental Science and Technology for the Eart

La décroissance bêta des produits de fission pour la non-prolifération et la puissance résiduelle des réacteurs nucléaires

Aujourd hui, l énergie nucléaire représente une partie non-négligeable du marché énergétique mondial, très probablement vouée à croître dans les prochaines décennies. Les réacteurs du futur devront notamment répondre à des critères supplémentaires économiques mais surtout de sûreté, de non-prolifération, de gestion optimisée du combustible et d une gestion responsable des déchets nucléaires. Dans le cadre de cette thèse, des études concernant la non-prolifération des armes nucléaires sont abordées, dans le cadre de la recherche et développement d un nouvel outil potentiel de surveillance des réacteurs nucléaires ; la détection des antineutrinos des réacteurs. En effet, les propriétés de ces particules pourraient intéresser l Agence Internationale de l Energie Atomique (AIEA) en charge de l application du Traité de non-prolifération des armes nucléaires. L AIEA encourage ainsi ses états membres à mener une étude de faisabilité. Une première étude de non-prolifération est réalisée avec la simulation d un scénario proliférant utilisant un réacteur de type CANDU et de l émission en antineutrinos associée. Nous en déduisons une prédiction de la sensibilité d un détecteur d antineutrinos de taille modeste à la diversion d une quantité significative de plutonium. Une seconde étude est réalisée dans le cadre du projet Nucifer, détecteur d antineutrinos placé auprès du réacteur de recherche OSIRIS. Nucifer est un détecteur d antineutrinos dédié à la non-prolifération à l efficacité optimisée conçu pour être un démonstrateur pour l AIEA. La simulation du réacteur OSIRIS est développée ici pour le calcul de l émission d antineutrinos qui sera comparée aux données mesurées par le détecteur ainsi que pour caractériser le bruit de fond important émis par le réacteur détecté dans Nucifer. De façon générale, les antineutrinos des réacteurs sont émis lors des décroissances radioactives des produits de fission. Ces décroissances radioactives sont également à l origine de la puissance résiduelle émise après l arrêt d un réacteur nucléaire, dont l estimation est un enjeu de sûreté. Nous présenterons dans cette thèse un travail expérimental dont le but est de mesurer les propriétés de décroissance bêta de produits de fission importants pour la non-prolifération et la puissance résiduelle des réacteurs. Des premières mesures utilisant la technique de Spectroscopie par Absorption Totale (TAGS) ont été réalisées auprès du dispositif de l Université de Jyväskylä. Nous présenterons la technique employée, le dispositif expérimental ainsi qu une partie de l analyse de cette expérience.Today, nuclear energy represents a non-negligible part of the global energy market, most likely a rolling wheel to grow in the coming decades. Reactors of the future must face the criteria including additional economic but also safety, non-proliferation, optimized fuel management and responsible management of nuclear waste. In the framework of this thesis, studies on non-proliferation of nuclear weapons are discussed in the context of research and development of a new potential tool for monitoring nuclear reactors, the detection of reactor antineutrinos, because the properties of these particles may be of interest for the International Agency of Atomic Energy (IAEA), in charge of the verification of the compliance by States with their safeguards obligations as well as on matters relating to international peace and security. The IAEA encouraged its member states to carry on a feasibility study. A first study of non-proliferation is performed with a simulation, using a proliferating scenario with a CANDU reactor and the associated antineutrinos emission. We derive a prediction of the sensitivity of an antineutrino detector of modest size for the purpose of the diversion of a significant amount of plutonium. A second study was realized as part of the Nucifer project, an antineutrino detector placed nearby the OSIRIS research reactor. The Nucifer antineutrino detector is dedicated to non-proliferation with an optimized efficiency, designed to be a demonstrator for the IAEA. The simulation of the OSIRIS reactor is developed here for calculating the emission of antineutrinos which will be compared with the data measured by the detector and also for characterizing the level of background noises emitted by the reactor detected in Nucifer. In general, the reactor antineutrinos are emitted during radioactive decay of fission products. These radioactive decays are also the cause of the decay heat emitted after the shutdown of a nuclear reactor of which the estimation is an issue of nuclear safety. In this thesis, we present an experimental work which aims to measure the properties of beta decay of fission products important to the non-proliferation and reactor decay heat. First steps using the technique of Total Absorption Gamma-ray Spectroscopy (TAGS) were carried on at the radioactive beam facility of the University of Jyvaskyla. We will present the technique used, the experimental setup and part of the analysis of this experiment.NANTES-ENS Mines (441092314) / SudocSudocFranceF

Economic impact of climate change on agriculture: a case of Vietnam

Food security, agricultural exports, and livelihoods have improved by rapid agricultural expansion in the previous 30 years. In the coming decades, warming trends and human pressures are expected to exacerbate the impact of climate change on agriculture. A time series of data from 1990 to 2020 examines the economic effects of climate change on Vietnamese farm production. After using the Augmented Dickey-Fuller and Philips-Perron unit root tests, the ARDL bounds testing technique estimates short and long-run cointegration. They found long-run cointegration between the variables. A positive influence of CO2 emissions is identified, although negative impacts of average temperature and rainfall are found. But only in the short term can energy consumption benefit agriculture. Non-climatic factors like crop production and fertiliser consumption have beneficial short- and long-term impacts on agriculture production and yield. Juselius Jhansen As well as proving long-term cointegration between variables. The report advises the Vietnamese government to create and implement many adaptation programmes to preserve the agriculture industry from climate change.Nguyen Van Huong (Faculty of Economics, Hung Yen University of Technology and Education (UTEHY)), Bui Thi Minh Nguyet (Vietnam National University of Forestry), Hoang Van Hung (Faculty of Economics, Hung Yen University of Technology and Education (UTEHY)), Hoang Minh Duc (Faculty of Economics, Hung Yen University of Technology and Education (UTEHY)), Nguyen Van Chuong (University of Financial and Business Administration (UFBA)), Do Minh Tri (Nguyen Van Linh Political School), Phung Van Hien (National Academy of Public Administration (NAPA))Includes bibliographical references

Neural network based patient recovery estimation of a PAM-based rehabilitation robot

Rehabilitation robots have shown a promise in aiding patient recovery by supporting them in repetitive, systematic training sessions. A critical factor in the success of such training is the patient’s recovery progress, which can guide suitable treatment plans and reduce recovery time. In this study, a neural network-based approach is proposed to estimate the patient’s recovery, which can aid in the development of an assist-as-needed training strategy for the gait training system. Experimental results show that the proposed method can accurately estimate the external torques generated by the patient to determine their recovery. The estimated patient recovery is used for an impedance control of a 2-DOF robotic orthosis powered by pneumatic artificial muscles, which improves the robot joint compliance coefficients and makes the patient more comfortable and confident during rehabilitation exercises

A DOUBLE-SHRINK AUTOENCODER FOR NETWORK ANOMALY DETECTION

The rapid development of the Internet and the wide spread of its applications has affected many aspects of our life. However, this development also makes the cyberspace more vulnerable to various attacks. Thus, detecting and preventing these attacks are crucial for the next development of the Internet and its services. Recently, machine learning methods have been widely adopted in detecting network attacks. Among many machine learning methods, AutoEncoders (AEs) are known as the state-of-the-art techniques for network anomaly detection. Although, AEs have been successfully applied to detect many types of attacks, it is often unable to detect some difficult attacks that attempt to mimic the normal network traffic. In order to handle this issue, we propose a new model based on AutoEncoder called Double-Shrink AutoEncoder (DSAE). DSAE put more shrinkage on the normal data in the middle hidden layer. This helps to pull out some anomalies that are very similar to normal data. DSAE are evaluated on six well-known network attacks datasets. The experimental results show that our model performs competitively to the state-of-the-art model, and often out-performs this model on the attacks group that is difficult for the previous methods

Optimal Design of V-Shaped Fin Heat Sink for Active Antenna Unit of 5G Base Station

The active antenna unit (AAU) is one of the main parts of the 5G base station, which has a large size and a high density of chipsets, and operates at a significantly high temperature. This systematic study presents an optimal design for the heat sink of an AAU with a V-shaped fin arrangement. First, a simulation of the heat dissipation was conducted on two designs of the heat sink – in-line and V-shaped fins – which was validated by experimental results. The result shows that the heat sink with V-shaped fins performed better compared to conventional models such as heat sinks with in-line fins. Secondly, computational fluid dynamics (CFD) and the Lagrange interpolation method were applied to find out an optimal set of design parameters for the heat sink. It is worth noting that the optimal parameters of the orientation angle and fin spacing considerably affected the heat sink’s performance.