Deviations of a random walk in a random scenery with stretched exponential tails

Let (Z_n)_{n\in\N_0} be a d-dimensional random walk in random scenery, i.e., Z_n=\sum_{k=0}^{n-1}Y_{S_k} with (S_k)_{k\in\N_0} a random walk in Z^d and (Y_z)_{z\in Z^d} an i.i.d. scenery, independent of the walk. We assume that the random variables Y_z have a stretched exponential tail. In particular, they do not possess exponential moments. We identify the speed and the rate of the logarithmic decay of Pr(Z_n>t_n n) for all sequences (t_n)_{n\in\N} satisfying a certain lower bound. This complements previous results, where it was assumed that Y_z has exponential moments of all orders. In contrast to the previous situation,the event \{Z_n>t_nn\} is not realized by a homogeneous behavior of the walk's local times and the scenery, but by many visits of the walker to a particular site and a large value of the scenery at that site. This reflects a well-known extreme behavior typical for random variables having no exponential moments.Comment: 12 page

Weighted norm inequalities, off-diagonal estimates and elliptic operators. Part I: General operator theory and weights

This is the first part of a series of four articles. In this work, we are interested in weighted norm estimates. We put the emphasis on two results of different nature: one is based on a good-$\lambda$ inequality with two-parameters and the other uses Calder\'on-Zygmund decomposition. These results apply well to singular 'non-integral' operators and their commutators with bounded mean oscillation functions. Singular means that they are of order 0, 'non-integral' that they do not have an integral representation by a kernel with size estimates, even rough, so that they may not be bounded on all $L^p$ spaces for $1 < p < \infty$. Pointwise estimates are then replaced by appropriate localized $L^p-L^q$ estimates. We obtain weighted $L^p$ estimates for a range of $p$ that is different from $(1,\infty)$ and isolate the right class of weights. In particular, we prove an extrapolation theorem ' \`a la Rubio de Francia' for such a class and thus vector-valued estimates.Comment: 43 pages. Series of 4 paper

Relationship between Real Earnings Management with Cost of Debt in Chinese Listed High-Tech Enterprises: The Perspective of Corporate Income Tax Incentives

To encourage corporate investment in innovation or R&D and foster innovative firms, the government of China established standards for the certification of high-tech enterprises in 2008. The business entities that fulfill these standards are entitled to tax deductions. One of the criteria is the ratio of R&D expenses to sales exceeding a specific percentage (which depends on the annual revenue) in the preceding 3 years. Moreover, this study examines data from the CSMAR database for the period 2008-2019 and includes data from 8,233 listed high-tech enterprises. The results show that if the proportion of pre-managed R&D expenses to pre-managed sales that are less than 6% (or 5%), 4%, or 3% in the past three years of firms with different sales range in the current year and managed earnings through sales or R&D expenses to fulfill the standards required for the certification positively influenced the costs of debt (non-significant)

Improved integrated real-time contamination monitor

The laboratory model of the ITREM including the photomultiplier is described along with the utilization of the instrument. The preliminary designs are reviewed, and the development of the optical module for the instrument is discussed

Protocolo de estudio de las infecciones del tracto reproductor masculino en reproducción humana asistida

El diagnóstico de esterilidad masculina habitualmente se basa en el análisis del semen. Sin embargo, la Infección del Tracto Reproductor Masculino (ITREM) es uno de los factores que pueden contribuir a la misma. Se determina la conveniencia de incorporar el cribado microbiológico de los pacientes asintomáticos a estudio de esterilidad del Área Sanitaria de Santiago de Compostela, estableciendo el protocolo más adecuado, así como la eficacia del tratamiento antimicrobiano en los casos positivos. Para ello se evalúa la prevalencia de los principales microorganismos asociados a ITREM mediante el protocolo de Meares y Stamey modificado y técnicas moleculares, se evalúa la validez del cuestionario NIH-CPSI como herramienta para el diagnóstico presuntivo de prostatitis, y se analiza la relación existente entre la presencia de microorganismos y los parámetros de calidad seminal así como con el factor femenino de esterilidad

Estudio del mercado turístico de Costa Cálida

Ciencias de la Comunicació

Клинико-экспериментальная оценка применения нанонаполненного стеклоиономерного цемента Ketac N-100 для эстетико-функциональной реставрации зубов

Результаты проведенного экспериментального и клинического исследования свидетельствуют об эффективном использовании в качестве пломбировочного материала кариозных и некариозных дефектов твердых тканей зубов пришеечной локализации нанонаполненного стеклоиономерного цемента Ketac N-100. По сравнению с традиционным СИЦ Vitremer были выявлены эстетические преимущества Ketac N-100 (цветопередача, полируемость), а по сравнению с нанокомпозитом Filtek Supreme XT - улучшение сохранности пломб, особенно у больных с низким уровнем резистентности к кариесу в течение года наблюдения. Полученные данные позволяют рекомендовать новый нанонаполненный СИЦ для восстановления дефектов пришеечной области как материал выбора

Influence des tests d'intrusion sur l'évaluation des risques

La sécurité de l’information est un domaine prenant un essor considérable suite aux attaques informatiques fréquentes ayant fait l’objet d’une couverture médiatique internationale, depuis les dix dernières années. Nous sommes donc à l’ère où la protection de l’information numérique représente un enjeu capital pour les entreprises et les gouvernements. Ces acteurs sont de plus en plus sujets à la numérisation de leur processus d’affaires et des documents associés. Les attaques informatiques auxquelles ils sont exposés ont donc des impacts d’autant plus importants selon la criticité de l’information. L’évaluation des risques informatiques est la discipline permettant d’analyser les actifs informationnels détenus par ces acteurs. Elle a pour but d’en évaluer les différents aspects de sécurité afin d’identifier les risques, les évaluer et formuler des recommandations pour les réduire. Pour cela, les méthodologies actuelles d’évaluation des risques se basent principalement sur des scénarios de menaces pouvant potentiellement se matérialiser sur l’environnement informatique d’une entreprise. Ces approches prennent pour acquis que la démarche d’analyse de risque repose principalement sur l’énumération de scénarios de menaces qui sont génériques et peu adaptés à l’environnement de l’entreprise concernée. Nous sommes donc arrivés à nous questionner sur plusieurs aspects liés à la validité des processus d’analyse et d’évaluation des risques informatiques. Cette notion de risque informatique n’a cessé de croître durant les vingt dernières années, et ce principalement dû à la médiatisation des incidents de sécurité ainsi qu’à la prise de conscience concernant l’importance des actifs informationnels numériques, tant du côté corporatif qu’individuel. L’évaluation des risques informatiques est désormais une des préoccupations principales des entreprises soucieuses de la protection liée à leurs actifs informationnels.----------ABSTRACT: The security of digital information is an area of extreme importance nowadays, since the various attacks on the Internet have been the focus of international media coverage for the last ten years. We therefore are in an era where the protection of information is a key issue for businesses and governments. These actors are increasingly subject to the digitization of their business processes and related documents. The attacks they are exposed to can have severe impacts depending on the criticality of the proprietary information concerned. Computer risk assessment is the discipline used to analyze the information assets held by these enterprises and governments. Its purpose is to evaluate the various aspects of security in order to identify risks, evaluate them, and implement recommendations to reduce them. To this end, current risk assessment methodologies are based mainly on threat scenarios that could potentially materialize on a company's digital environment. These approaches enforce that the risk analysis approach relies mainly on the enumeration of threat scenarios that are generic and not adapted to the digital environment of the company concerned. Thus, we have come to question several aspects related to the validity of the processes of analysis and evaluation of computer risks. This notion of computer risk has kept increasing for the last twenty years, mainly due to media coverage of security incidents and to raising awareness about the importance of securing digital assets. IT security risk assessment is now one of the main concerns of companies concerned about the protection of their information assets