761 research outputs found

    Multi-Attribute Utility Model for Selection of Appropriate Procurement Method in the Construction Projects

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    The selection of an appropriate procurement method is becoming an increasingly important issue due to complex decision-making that has to be made by clients early in the project lifecycle. The aim at this paper is to improve and enhance procurement system in the construction industry through developing a model using the multi-attribute utility theory (MAUT) as a decision support system for the selection of appropriate procurement method for construction projects in the Gaza Strip. Factors that influence the selection of an appropriate method for construction projects in Gaza Strip were identified. The results indicated that the top significant six factors that have most influence on the selection of procurement methods in the Gaza Strip construction projects are: price competition, degree of project complexity, time constrains of project, project size, client's financial capability, and client's experience in procurement methods. The study concludes that there is no variety of procurement methods used in the Gaza Strip construction industry where a traditional procurement method is preferred. This is because most of professionals' in Gaza Strip are not familiar and not widely experienced with the other alternative procurement methods. A model was developed using Multi Atrribute Utility Theory to select the most appropriate procurement method. The multi-attribute utility-theory (MAUT) as a decision support system was able to identify the appropriate procurement method

    Multi-Attribute Utility Theory for Selecting an Appropriate Procurement Method in the Construction Projects

    Get PDF
    The selection of an appropriate procurement method is becoming an increasingly important issue due to complex decision making that clients are facing early in the lifecycle of construction projects. The aim of this paper is to improve the procurement system in the construction industry by developing a model using the multi-attribute utility theory (MAUT) as a decision support system for the selection of an appropriate procurement method for construction projects in the Gaza Strip. Factors that influence the selection of an appropriate method for construction projects in the Gaza Strip are identified and the results indicate that the most significant six factors influencing the selection of procurement methods in the Gaza Strip construction projects are price competition, degree of project complexity, time constraints of the project, project size, client financial capability and client experience in procurement methods. The study concludes that there is no variety of procurement methods used in the Gaza Strip construction industry, as a traditional procurement method is preferred. This is because most professionals in the Gaza Strip are not familiar or experienced with alternative procurement methods. A model was developed using the MAUT to select the most appropriate procurement method. The MAUT as a decision support system was successful in identifying the appropriate procurement method

    Theoretical and experimental studies of a switched inertance hydraulic system in a four-port high speed switching valve configuration

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    The switched inertance hydraulic system (SIHS) is a novel high-bandwidth and energy-efficient digital device which can adjust or control flow and pressure by a means that does not rely on throttling the flow and dissipation of power. An SIHS can provide an efficient step-up or step-down of pressure or flow rate by using a digital control signal. In this article, analytical models of an SIHS in a four-port high-speed switching valve configuration are proposed, and the system dynamics and performance are investigated theoretically and experimentally. The flow responses, system characteristics, and power consumption can be predicted effectively and accurately by using the proposed models, which were validated by comparing with experiments and with numerical simulation. The four-port configuration is compared with the three-port configuration, and it is concluded that the former one is less efficient for valves of the same size, but provides a bi-direction control capability. As bi-direction control is a common requirement, this constitutes an important contribution to the development of efficient digital hydraulics

    Arab Students at Five Oklahoma Institutions of Higher Education: A Study of Academic Achievement

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    Higher Educatio

    The environmental impact on the hydrogeochemical characterization of the Kurkar aquifer system, Gaza strip, Palestine.

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    The Gaza strip is suffering groundwater deterioration as a result of high population density where the outflow exceeds inflow by about 20 Mm3/y. This quantity of water is believed to be replaced by deep seawater intrusion and/or upconing of deep brines in the southern areas or by anthropogenic wastewater. Large cones of depression have been formed over the last 40 years within the Gaza, Khan Younis, and Rafah governorates. The salinity increases in the northwestern and the southeastern parts of Gaza Strip. Nitrate and chloride exceed the WHO maximum permissible limits and are considered as the major pollutants of the aquifer, their high concentration values are attributed to agricultural activity and leaked wastewaters as well as the scarcity of the resource. The cluster analysis (Q-mode) classified the data into 5 clusters and 3 independent cases depending upon salinity and nitrate concentrations. The rotated factor analysis identified 3 factors. The AquaChem program clarified that the study area was supersaturated with calcite and dolomite and undersaturated with gypsum and anhydrite minerals. In general, the groundwater was unsuitable for drinking according to their TDS and NO3 contents. The groundwater can be used in permeable soils for irrigation purposes

    A Survey on Malware Detection with Graph Representation Learning

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    Malware detection has become a major concern due to the increasing number and complexity of malware. Traditional detection methods based on signatures and heuristics are used for malware detection, but unfortunately, they suffer from poor generalization to unknown attacks and can be easily circumvented using obfuscation techniques. In recent years, Machine Learning (ML) and notably Deep Learning (DL) achieved impressive results in malware detection by learning useful representations from data and have become a solution preferred over traditional methods. More recently, the application of such techniques on graph-structured data has achieved state-of-the-art performance in various domains and demonstrates promising results in learning more robust representations from malware. Yet, no literature review focusing on graph-based deep learning for malware detection exists. In this survey, we provide an in-depth literature review to summarize and unify existing works under the common approaches and architectures. We notably demonstrate that Graph Neural Networks (GNNs) reach competitive results in learning robust embeddings from malware represented as expressive graph structures, leading to an efficient detection by downstream classifiers. This paper also reviews adversarial attacks that are utilized to fool graph-based detection methods. Challenges and future research directions are discussed at the end of the paper.Comment: Preprint, submitted to ACM Computing Surveys on March 2023. For any suggestions or improvements, please contact me directly by e-mai

    Multi-Attribute Utility Theory for Selecting an Appropriate Procurement Method in the Construction Projects

    Get PDF
    The selection of an appropriate procurement method is becoming an increasingly important issue due to complex decision making that clients are facing early in the lifecycle of construction projects. The aim of this paper is to improve the procurement system in the construction industry by developing a model using the multi-attribute utility theory (MAUT) as a decision support system for the selection of an appropriate procurement method for construction projects in the Gaza Strip. Factors that influence the selection of an appropriate method for construction projects in the Gaza Strip are identified and the results indicate that the most significant six factors influencing the selection of procurement methods in the Gaza Strip construction projects are price competition, degree of project complexity, time constraints of the project, project size, client financial capability and client experience in procurement methods. The study concludes that there is no variety of procurement methods used in the Gaza Strip construction industry, as a traditional procurement method is preferred. This is because most professionals in the Gaza Strip are not familiar or experienced with alternative procurement methods. A model was developed using the MAUT to select the most appropriate procurement method. The MAUT as a decision support system was successful in identifying the appropriate procurement method

    Mesenchymal adenomatous polyposis coli plays critical and diverse roles in regulating lung development.

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    BackgroundAdenomatous polyposis coli (Apc) is a tumor suppressor that inhibits Wnt/Ctnnb1. Mutations of Apc will not only lead to familial adenomatous polyposis with associated epithelial lesions, but will also cause aggressive fibromatosis in mesenchymal cells. However, the roles of Apc in regulating mesenchymal cell biology and organogenesis during development are unknown.ResultsWe have specifically deleted the Apc gene in lung mesenchymal cells during early lung development in mice. Loss of Apc function resulted in immediate mesenchymal cell hyperproliferation through abnormal activation of Wnt/Ctnnb1, followed by a subsequent inhibition of cell proliferation due to cell cycle arrest at G0/G1, which was caused by a mechanism independent of Wnt/Ctnnb1. Meanwhile, abrogation of Apc also disrupted lung mesenchymal cell differentiation, including decreased airway and vascular smooth muscle cells, the presence of Sox9-positive mesenchymal cells in the peripheral lung, and excessive versican production. Moreover, lung epithelial branching morphogenesis was drastically inhibited due to disrupted Bmp4-Fgf10 morphogen production and regulation in surrounding lung mesenchyme. Lastly, lung mesenchyme-specific Apc conditional knockout also resulted in altered lung vasculogenesis and disrupted pulmonary vascular continuity through a paracrine mechanism, leading to massive pulmonary hemorrhage and lethality at mid-gestation when the pulmonary circulation should have started.ConclusionsOur study suggests that Apc in lung mesenchyme plays central roles in coordinating the proper development of several quite different cellular compartments including lung epithelial branching and pulmonary vascular circulation during lung organogenesis

    Heavy Metals Distribution and Pollution in the Sediments of the Wadi Gaza Mouth, Eastern Mediterranean Coast, Palestine

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    Wadi Gaza is the most important wetland in Gaza Strip. Due to the difficult economic conditions, the Israeli occupation and lack of the resources, Wadi Gaza became a place for solid and liquid waste disposal from surrounding provinces. The aim of this study is to assess the heavy metals in the sediments of the Wadi Gaza, North, and South of downstream along the beach of Gaza Strip. This was achieved through sediment sampling along the course of the Wadi downstream; north and south of the beach sands, and the geochemical analysis was done in the Ministry of Health Laboratories. The concentrations of Mn, Zn, Ni, Cd, Cu, and Pb were determined in the sediments, using atomic absorption spectrophotometer
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