A class of stochastic differential equations with super-linear growth and non-Lipschitz coefficients

The purpose of this paper is to study some properties of solutions to one dimensional as well as multidimensional stochastic differential equations (SDEs in short) with super-linear growth conditions on the coefficients. Taking inspiration from \cite{BEHP, KBahlali, Bahlali}, we introduce a new {\it{local condition}} which ensures the pathwise uniqueness, as well as the non-contact property. We moreover show that the solution produces a stochastic flow of continuous maps and satisfies a large deviations principle of Freidlin-Wentzell type. Our conditions on the coefficients go beyond the existing ones in the literature. For instance, the coefficients are not assumed uniformly continuous and therefore can not satisfy the classical Osgood condition. The drift coefficient could not be locally monotone and the diffusion is neither locally Lipschitz nor uniformly elliptic. Our conditions on the coefficients are, in some sense, near the best possible. Our results are sharp and mainly based on Gronwall lemma and the localization of the time parameter in concatenated intervalsComment: in Stochastics An International Journal of Probability and Stochastic Processes, 201

Heterobasidion root rot infections on Scots pine : A cryptic threat to sustainable forest management in Sweden

Root rot caused by Heterobasidion poses a severe threat to sustainable forestry in managed Scots pine stands in Sweden. In Scots pine, the disease remains hidden in the roots, leading to tree mortality and growth losses. Its cryptic nature often results in underestimated losses and insufficient management action. This thesis aims to highlight the issues posed by Heterobasidion in typical forest conditions, explores more efficient methods for disease identification, and assess the potential for future breeding of resistance in Scots pine. This work has been conducted under a combination of field and greenhouse conditions. Scots pine trees in stands designated as low-risk sites for Heterobasidion infection were examined for signs of infection in the crown. Subsequently, trees were uprooted, and samples were analysed for the presence of Heterobasidion infection. Drone imagery was used, and bud samples were retrieved for genetic analyses. In the greenhouse, the histological response to infection was analysed. A key finding of this study was the high prevalence of hidden infections in the roots of Scots pine trees on low-risk sites. Furthermore, the prevalence of these infections was positively correlated with site index, meaning that trees on higher-fertility soils were more likely to be infected. This finding calls for a change in forest management practices, specifically the application of stump treatment to Scots pine wherever Heterobasidion annosum is present in Sweden. Scots pine's response to infection, characterized by the formation of traumatic resin ducts, is local and impractical for effective disease detection or dating of infections. The use of drones equipped with RGB sensors demonstrated promising results, warranting further interest and development. Research is needed to explore how this technology can be applied to identifying Heterobasidion among other stressors. Heterobasidion is clearly a significant issue in Swedish forestry that deserves more attention. This thesis establishes that a promising genetic component can aid in selecting more resistant trees. In summary, this thesis underscores the cryptic nature of Heterobasidion disease on Scots pine, introduces available tools, and highlights the promising potential for further development

OSCAR: A Collaborative Bandwidth Aggregation System

The exponential increase in mobile data demand, coupled with growing user expectation to be connected in all places at all times, have introduced novel challenges for researchers to address. Fortunately, the wide spread deployment of various network technologies and the increased adoption of multi-interface enabled devices have enabled researchers to develop solutions for those challenges. Such solutions aim to exploit available interfaces on such devices in both solitary and collaborative forms. These solutions, however, have faced a steep deployment barrier. In this paper, we present OSCAR, a multi-objective, incentive-based, collaborative, and deployable bandwidth aggregation system. We present the OSCAR architecture that does not introduce any intermediate hardware nor require changes to current applications or legacy servers. The OSCAR architecture is designed to automatically estimate the system's context, dynamically schedule various connections and/or packets to different interfaces, be backwards compatible with the current Internet architecture, and provide the user with incentives for collaboration. We also formulate the OSCAR scheduler as a multi-objective, multi-modal scheduler that maximizes system throughput while minimizing energy consumption or financial cost. We evaluate OSCAR via implementation on Linux, as well as via simulation, and compare our results to the current optimal achievable throughput, cost, and energy consumption. Our evaluation shows that, in the throughput maximization mode, we provide up to 150% enhancement in throughput compared to current operating systems, without any changes to legacy servers. Moreover, this performance gain further increases with the availability of connection resume-supporting, or OSCAR-enabled servers, reaching the maximum achievable upper-bound throughput

Reconfigurable cable driven parallel mechanism

Due to the fast growth in industry and in order to reduce manufacturing budget, increase the quality of products and increase the accuracy of manufactured products in addition to assure the safety of workers, people relied on mechanisms for such purposes. Recently, cable driven parallel mechanisms (CDPMs) have attracted much attention due to their many advantages over conventional parallel mechanisms, such as the significantly large workspace and the dynamics capacity. In addition, it has lower mass compared to other parallel mechanisms because of its negligible mass cables compared to the rigid links. In many applications it is required that human interact with machines and robots to achieve tasks precisely and accurately. Therefore, a new domain of scientific research has been introduced, that is human robot interaction, where operators can share the same workspace with robots and machines such as cable driven mechanisms. One of the main requirements due to this interaction that robots should respond to human actions in accurate, harmless way. In addition, the trajectory of the end effector is coming now from the operator and it is very essential that the initial trajectory is kept unchanged to perform tasks such assembly, operating or pick and place while avoiding the cables to interfere with each other or collide with the operator. Accordingly, many issues have been raised such as control, vibrations and stability due the contact between human and robot. Also, one of the most important issues is to guarantee collision free space (to avoid collision between cables and operator and to avoid collisions between cables itself). The aim of this research project is to model, design, analysis and implement reconfigurable six degrees of freedom parallel mechanism driven by eight cables. The main contribution of this work will be as follow. First, develop a nonlinear model and solve the forward and inverse kinematics issue of a fully constrained CDPM given that the attachment points on the rails are moving vertically (conventional cable driven mechanisms have fixed attachment points on the rails) while controlling the cable lengths. Second, the new idea of reconfiguration is then used to avoid interference between cables and between cables and operator limbs in real time by moving one cable’s attachment point on the frame to increase the shortest distance between them while keeping the trajectory of the end effector unchanged. Third, the new proposed approach was tested by creating a simulated intended cable-cable and cable-human interference trajectory, hence detecting and avoiding cable-cable and cable-human collision using the proposed real time reconfiguration while maintaining the initial end effector trajectory. Fourth, study the effect of relocating the attachment points on the constant-orientation wrench feasible workspace of the CDPM. En raison de la croissance de la demande de produits personnalisés et de la nécessité de réduire les coûts de fabrication tout en augmentant la qualité des produits et en augmentant la personnalisation des produits fabriqués en plus d'assurer la sécurité des travailleurs, les concepteurs se sont appuyés sur des mécanismes robotiques afin d’atteindre ces objectifs. Récemment, les mécanismes parallèles entraînés par câble (MPEC) ont attiré beaucoup d'attention en raison de leurs nombreux avantages par rapport aux mécanismes parallèles conventionnels, tels que l'espace de travail considérablement grand et la capacité dynamique. De plus, ce mécanisme a une masse plus faible par rapport à d'autres mécanismes parallèles en raison de ses câbles de masse négligeable comparativement aux liens rigides. Dans de nombreuses applications, il est nécessaire que l’humain interagisse avec les machines et les robots pour réaliser des tâches avec précision et rapidité. Par conséquent, un nouveau domaine de recherche scientifique a été introduit, à savoir l'interaction humain-robot, où les opérateurs peuvent partager le même espace de travail avec des robots et des machines telles que les mécanismes entraînés par des câbles. L'une des principales exigences en raison de cette interaction que les robots doivent répondre aux actions humaines d'une manière sécuritaire et collaboratif. En conséquence, de nombreux problèmes ont été soulevés tels que la commande et la stabilité dues au contact physique entre l’humain et le robot. Aussi, l'un des enjeux les plus importants est de garantir un espace sans collision (pour éviter les collisions entre des câbles et un opérateur et éviter les collisions entre les câbles entre eux). Le but de ce projet de recherche est de modéliser, concevoir, analyser et mettre en œuvre un mécanisme parallèle reconfigurable à six degrés de liberté entraîné par huit câbles. La principale contribution de ces travaux de recherche est de développer un modèle non linéaire et résolvez le problème de cinématique direct et inverse d'un CDPM entièrement contraint étant donné que les points d'attache sur les rails se déplacent verticalement (les mécanismes entraînés par des câbles conventionnels ont des points d'attache fixes sur les rails) tout en contrôlant les longueurs des câbles. Dans une deuxième étape, l’idée de la reconfiguration est ensuite utilisée pour éviter les interférences entre les câbles et entre les câbles et les membres d’un opérateur en temps réel en déplaçant un point de fixation du câble sur le cadre pour augmenter la distance la plus courte entre eux tout en gardant la trajectoire de l'effecteur terminal inchangée. Troisièmement, la nouvelle approche proposée a été évaluée et testée en créant une trajectoire d'interférence câble-câble et câble-humain simulée, détectant et évitant ainsi les collisions câble-câble et câble-humain en utilisant la reconfiguration en temps réel proposée tout en conservant la trajectoire effectrice finale. Enfin la dernière étape des travaux de recherche consiste à étudiez l'effet du déplacement des points d'attache sur l'espace de travail réalisable du CDPM

Unconventional TV Detection using Mobile Devices

Recent studies show that the TV viewing experience is changing giving the rise of trends like "multi-screen viewing" and "connected viewers". These trends describe TV viewers that use mobile devices (e.g. tablets and smart phones) while watching TV. In this paper, we exploit the context information available from the ubiquitous mobile devices to detect the presence of TVs and track the media being viewed. Our approach leverages the array of sensors available in modern mobile devices, e.g. cameras and microphones, to detect the location of TV sets, their state (ON or OFF), and the channels they are currently tuned to. We present the feasibility of the proposed sensing technique using our implementation on Android phones with different realistic scenarios. Our results show that in a controlled environment a detection accuracy of 0.978 F-measure could be achieved.Comment: 4 pages, 14 figure

Priority allocation decisions in large scale MTO/MTS multi-product manufacturing systems : Technical report

In this paper, the authors consider a single stage multi-product manufacturing facility producing a large number of end-products for delivery within a service constraint for the customer lead-time. The manufacturing facility is modeled as a multi-product, multi-priority queuing system. In order to reduce inventory costs, an e±cient priority allocation between items consists in producing some items according to a Make-To-Stock (MTS) policy and others according to a Make-To-Order (MTO)policy epending on their features (costs, required lead-time, demand rates). The authors propose a general optimization procedure that gives a near-optimal °ow control (MTO or MTS) to associate with each product and the corresponding near-optimal priority strategy. We illustrate e±ciency of our procedure via several examples and by a numerical analysis. In addition, we show numerically that a small number of priority classes is su±cient to obtain near-optimal performances.Make-to-Stock (MTS); Make-to-Order (MTO); Priority allocation; Scheduling rule; Heterogeneous multi-product queuing system

The Giza Pyramids: A History of Wireless Electricity Transmission Validated by Today’s Science

This paper conducts a review to a recent theory that was introduced by Christopher Dunn in 1998 and 2010. This theory suggests that the ancient Egyptians had the technology to generate and wirelessly transmit electrical energy using the Great Pyramids of Giza. Also, the paper makes a comparison between the principle of this old technology to what is being developed in the present time to achieve wireless and efficient transmission of the electric energy