5,433 research outputs found

    Key Decision-Making Phases and Tasks for Outsourcing Information Technology

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    Flood Risk Mapping and Management in Urban Areas: Integrating Geomatics and Hydrodynamic Modeling - A Case Study of Al Bidi City, Saudi Arabia

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    In this paper, we focus on developing a comprehensive approach to map and manage flood risks in Al Bidi City, located in the Al-Aflaj Governorate of Saudi Arabia. By integrating geomatics (Remote Sensing and GIS) and hydrodynamic modeling (PCSWMM and HEC-RAS), the study aims to simulate and model flood risks in populated areas under different scenarios, considering the impact of climate change. The study generates three integrated maps: flood intensity, environmental sensitivity, and flood risks. Strategic solutions and mitigation measures are proposed based on the findings. The results indicate that Al Bidi City is exposed to flood risks originating from the west and progressing towards the east, primarily due to significant valleys such as Wadi Harm. Approximately 60% of the urban area is affected by torrential water. The study proposes the construction of embankments, channels, and culverts to redirect floodwaters to Wadi Al Jadwal in the east, as well as the implementation of industrial channels to manage floods in the northern valleys

    A wideband 3-dB directional coupler in GGW for use in V-Band communication systems

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    In this article, a broadband 3-dB directional coupler is proposed using groove gap waveguide (GGW) structures. Gap waveguide technology has been introduced to overcome manufacturing and assembling challenges of different millimeter-wave components and devices. The presented coupler has wideband coupling flatness with low return loss in 60-GHz frequency band and can be easily adapted to other frequency ranges. Experimentally, a sample prototype of the proposed 3-dB coupler has been designed and fabricated. The measured return loss and isolation are better than 20 dB and the power-split unbalance within \ub10.5 dB is obtained over the frequency range from 57 to 74 GHz (26% BW). The proposed structure has the capability of easily integrating with other millimeter-wave components

    Pollutant Removal from Highway Runoff Using Retention/Detention Units

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    Highway runoff contains total suspended solids, hydrocarbons, oil and greases, chloride, and other contaminants that are transported in solution and particulate forms to adjacent floodplains, roadside swales, and retention/detention ponds. Oil and grit chambers represent a type of retention/detention unit used for removing heavy particulates and adsorbed hydrocarbon particulates. Storage/sediment units also represent a type of retention/detention unit used for controlling peak flow and removing suspended solids. The aim of this study is to evaluate the effect of traffic volume and site characteristics on highway runoff quality. The study also aims to evaluate the performance of retention/detention units that collect runoff from the Prague-Brno and Prague-Plzeň highways, Czech Republic. The results of this study indicate no definitive relationship between average daily traffic and concentration of runoff constituents, though the site characteristics have a strong relation to some constituents. The results also show that retention/detention units are effective in treating organic compounds

    Axiomatic/asymptotic evaluation of multilayered plate theories by using single and multi-points error criteria

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    AbstractThis paper deals with refined theories for multilayered composites plates. Layer-Wise (LW) and Equivalent Single Layer (ESL) theories are evaluated by means of axiomatic–asymptotic approach. Theories with forth order displacement fields in the thickness layer/plate direction z are implemented by referring to the Unified Formulation by Carrera. The effectiveness of each term of the made expansion is evaluated by comparing the related theories with a reference solution. As a result a reduced model is obtained which preserve the accuracy of the full-model (model that include the whole terms of the z-expansion) but it removes the not-significant terms in the same expansion (those terms that do no improve the results according to a given error criteria). Various single-point and multi-point error criteria have been analyzed and compared in order to establish such an effectiveness: error localized in an assigned point along z, error localized at each interface, error located at the z-value corresponding to the maximum value of the considered variables, etc. Applications are given in case of closed form solutions of orthotropic cross-ply, rectangular, simply supported plates loaded by bisinusoidal distribution of transverse pressure. Symmetrically and unsymmetrical laminated cases are considered along with sandwich plates. It is found the reduced model is strongly influenced by the used localized error and that in same case the reduced model which is obtained by of single point criteria can be very much improved by the use of multi-point criteria

    The serial blocking effect: a testbed for the neural mechanisms of temporal-difference learning

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    Temporal-difference (TD) learning models afford the neuroscientist a theory-driven roadmap in the quest for the neural mechanisms of reinforcement learning. The application of these models to understanding the role of phasic midbrain dopaminergic responses in reward prediction learning constitutes one of the greatest success stories in behavioural and cognitive neuroscience. Critically, the classic learning paradigms associated with TD are poorly suited to cast light on its neural implementation, thus hampering progress. Here, we present a serial blocking paradigm in rodents that overcomes these limitations and allows for the simultaneous investigation of two cardinal TD tenets; namely, that learning depends on the computation of a prediction error, and that reinforcing value, whether intrinsic or acquired, propagates back to the onset of the earliest reliable predictor. The implications of this paradigm for the neural exploration of TD mechanisms are highlighted
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