602 research outputs found

    Generalized Uncertainty Principle as a Consequence of the Effective Field Theory

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    We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because, in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counterterms for this scalar field theory deformed by the generalized uncertainty principle and show that the generalized uncertainty principle contributes to the matter conformal anomaly.Comment: 15 pages, no figures, Accepted for Publication in Physics Letters

    Automated Mapping Of Accessibility Signs With Deep Learning From Ground-level Imagery and Open Data

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    International audienceIn some areas or regions, accessible parking spots are not geolocalized and therefore both difficult to find online and excluded from open data sources. In this paper, we aim at detecting accessible parking signs from street view panoramas and geolocalize them. Object detection is an open challenge in computer vision, and numerous methods exist whether based on handcrafted features or deep learning. Our method consists of processing Google Street View images of French cities in order to geolocalize the accessible parking signs on posts and on the ground where the parking spot is not available on GIS systems. To accomplish this, we rely on the deep learning object detection method called Faster R-CNN with Region Proposal Networks which has proven excellent performance in object detection benchmarks. This helps to map accurate locations of where the parking areas do exist, which can be used to build services or update online mapping services such as Open Street Map. We provide some preliminary results which show the feasibility and relevance of our approach

    Lubricating Oil Additives

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    Identify and Analyze the Most Important Factors Affecting the Safety of Employees in Construction Sites in Iraq

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    تعد المشاريع الانشائية من أخطر الصناعات الانشائية من حيث تعرض سلامة وصحة العمال للحوادث المتنوعة والخطرة اثناء عملية البناء. إذ تبين احصائيات منظمة العمل الدولية وجود حادثة وفاة كل ثلاثة دقائق نتيجة إصابة العمال وان هنالك اربع إصابات مختلفة تحدث في العالم كل ثانية.  وقد تم تحديد صناعة البناء باعتبارها واحدة من الصناعات الأكثر خطورة، وذلك بسبب طبيعة العمل الناتج عن تكامل المواد والأدوات والبيئة والعوامل البشرية المختلفة حيث من الضروري إعطاء أهمية قصوى للسلامة المهنية والصحية للعمالة في مواقع المشاريع الانشائية وذلك لتقليل المخاطر والخسائر بين العمالة. حيث يعاني العراق من عدم الاهتمام بسلامة وصحة العمالة. ورغم أهمية السلامة والصحة للعاملين نلاحظ ان الأبحاث التي تطرقت لموضوع السلامة في المشاريع الانشائية تضل قليلة. يبدو أن الدراسات التجريبية حول تأثير الثقافة الوطنية على مواقف وسلوك وأداء السلامة قليلة. لا يبدو من غير المعقول أن نتوقع أن تختلف مواقف الناس تجاه المخاطر وفقًا للقيم والمعتقدات والافتراضات العميقة. لذا تم التركيز في هذا على اهم العوامل المؤثرة على سلامة وصحة العاملين في المواقع الانشائية وعمل اقتراحات حول من يتحمل هذه الإصابات صاحب العمل او المقاول ويتم ذكر كافة إجراءات السلامة اثناء كتابة عقد المقاولة ووضعها من الشروط الأساسية في المشروع.Construction sites are among the most dangerous construction industries in terms of exposing the safety and health of workers to various dangerous accidents during the construction process. Where the statistics of the International Labor Organization show that there is one death every three minutes as a result of a work injury and that there are four different injuries occurring in the world every second. The construction industry has been identified as one of the most dangerous industries, due to the nature of the work resulting from the integration of materials, tools, the environment and various human factors. A message of worker safety consideration during design sites. It is necessary to give the highest importance to the occupational and health safety of workers in construction projects sites in order to reduce risks and losses. Among worker. Iraq suffers from a lack of attention to safety and health of employment. Despite the importance of safety and health for workers, we note that research that deals with on the issue of safety in construction projects is still very little. Empirical studies on the effect of national culture on safety attitudes, behavior, and performance appear to be few. It does not seem unreasonable to expect people’s attitudes toward risk to differ according to the deep values, beliefs and assumptions that local culture influences safety in projects. Therefore, the focus was on the most important factors affecting the safety and health of workers in construction sites and making suggestions about who bears these injuries to the employer or contractor and all safety measures are mentioned while writing the contract and placing them as basic conditions in the project.                                                     &nbsp

    Improvements of Primary and Secondary Control of the Turkish Power System for Interconnection with the European System

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    The Turkish power system suffers from frequency oscillations with 20 – 30 seconds period. This thesis focuses on solving the frequency control problem within the Turkish power system. Design criteria and requirements related to primary and secondary control are elaborated in order to establish the frequency stability of the isolated Turkish power system and to fulfil the requirements of the extended system after the interconnection of Turkey with the European system. On 18 September 2010 the Turkish power system was synchronized with the interconnected power systems of Continental Europe

    Identifying and Explaining Public Preferences for Renewable Energy Sources in Qatar

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    As a major natural gas and oil producer, Qatar has made significant strides towards its energy transition. This paper uses a survey research design with statistical tests to investigate citizens’ preferences for a wide range of energy resources. In this study, participants were asked to prioritize energy sources based on their environmental impact, price, benefits to Qatar’s economy, support of energy security, and ability to create jobs. The results showed that approximately two-thirds of the sample (n = 354) preferred renewable energy sources, particularly solar, which ranks first. Renewable energy sources were more likely to be favored by the group with greater knowledge of energy sources than those with limited knowledge, except for solar energy, which was preferred by both groups. Additionally, both natural gas and wind rank second in terms of preference, followed by hydropower. In contrast, nuclear power was not ranked, indicating a strong opposition to this type of energy. The study provides an evidence-based example of the tendency of citizens in a hydrocarbon-rich country to prefer renewable energy sources and natural gas. The energy policymakers need to collaborate with local communities so that citizens can participate in important future energy discussions to develop a personal connection to climate solutionsOpen Access funding provided by the Qatar National Library

    Quelques conséquences sociales des programmes d'ajustement structurel

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    Cet article n'a pas pour objectif de critiquer les programmes d'ajustement structurel ni d'en évaluer l'efficacité. Nous essaierons plutôt, dans ces pages, de mettre en évidence certaines de leurs conséquences sociales, ce qui suppose de définir les divers domaines qu'ils couvrent et de comprendre clairement leur interaction à la lumière des spécificités de chaque domaine. À cet effet, nous classerons les politiques d'ajustement en trois catégories, chacune pouvant être associée à un impact d..

    Urban Growth and Its Impact on Urban Heat Sink and Island Formation in the Desert City of Dubai.

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    The rapid pace of urban growth in Dubai has attracted the attention of economists, environmentalists and urban planners. This thesis quantifies the extent of urbanisation within the Emirate since the discovery of oil and investigates the impacts of such growth on urban temperatures. The study used remotely-sensed imagery in the absence of publicly available data on city growth and microclimate. The study used a hybrid classification method and landscape metrics to capture historical urban forms, rates and engines of growth in the Emirate. Stepwise multiple regression analysis techniques were subsequently used to investigate the relationship between the rate and form of urbanisation and the intensity of the urban heat sink between 1990 and 2011. Local Climate Zones were then developed to specifically investigate the impacts of urban geometry variables and proximity to water on both urban heat sinks during the day-time and urban heat islands during the night. The study revealed a significant increase in urban area over time (1972-2011) with accelerated phases of growth, linked to local and global economic conditions, occurring during specific periods. Physical urban growth has now outpaced population growth, indicating urban sprawl. This growth has occurred at the expense of sand and has included a significant increase in vegetation and water bodies unlike other desert cities in the Gulf region. The results demonstrated that urban growth has promoted a heat sink effect during daytime and that all urban land use types contributed to this effect. Urban albedo was not responsible for the daytime urban heat sink; other factors including the specific heat capacity of urban materials, urban geometry and proximity to the Gulf were mainly responsible. Furthermore, increases in vegetation cover and impervious surface cover over time have contributed to the daytime (morning) urban heat sink. At night-time, urban geometry and proximity to the Gulf were the major influences upon the formation of urban heat islands. This research contributes to better understanding of urbanisation in desert cities as demonstrated through Dubai, revealing previously unknown spatiotemporal variations in urban areas across the city through the use of a time-series of satellite images. The findings provide new insights into the impacts of land cover, land use, proximity to water and urban geometry on the formation of urban heat sinks and urban heat islands in the desert environment
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