89 resultados para drive-thru internet


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Plug-in hybrid electric vehicles (PHEVs) provide much promise in reducing greenhouse gas emissions and, thus, are a focal point of research and development. Existing on-board charging capacity is effective but requires the use of several power conversion devices and power converters, which reduce reliability and cost efficiency. This paper presents a novel three-phase switched reluctance (SR) motor drive with integrated charging functions (including internal combustion engine and grid charging). The electrical energy flow within the drivetrain is controlled by a power electronic converter with less power switching devices and magnetic devices. It allows the desired energy conversion between the engine generator, the battery, and the SR motor under different operation modes. Battery-charging techniques are developed to operate under both motor-driving mode and standstill-charging mode. During the magnetization mode, the machine's phase windings are energized by the dc-link voltage. The power converter and the machine phase windings are controlled with a three-phase relay to enable the use of the ac-dc rectifier. The power converter can work as a buck-boost-type or a buck-type dc-dc converter for charging the battery. Simulation results in MATLAB/Simulink and experiments on a 3-kW SR motor validate the effectiveness of the proposed technologies, which may have significant economic implications and improve the PHEVs' market acceptance

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Purpose
– This paper aims to examine what drives the adoption of different social sustainability supply chain practices. Research has shown that certain factors drive the adoption of environmental sustainability practices but few focus on social supply chain practices, delineate which practices are adopted or what drives their adoption.

Design/methodology/approach
– The authors examine the facilitative role of sustainability culture to explain the adoption of social sustainability supply chain practices: basic practices, consisting of monitoring and management systems and advanced practices, which are new product and process development and strategic redefinition. The authors then explore the role played by a firm’s entrepreneurial orientation in shaping and reinforcing the adoption of social sustainability supply chain practices. A survey of 156 supply chain managers in multiple industries in Ireland was conducted to test the relationship between the variables.

Findings
– The findings show that sustainability culture is positively related to all the practices, and entrepreneurial orientation impacts and moderates social sustainability culture in advanced social sustainability supply chain adoption.

Research limitations/implications
– As with any survey, this is a single point in time with a single respondent. Implications for managers include finding the right culture in the organisation to implement social sustainability supply chain management practices that go beyond monitoring to behavioural changes in the supply chain with implications beyond the dyad of buyer and supplier to lower tier suppliers and the community surrounding the supply chain.

Practical implications
– The implications for managers include developing and fostering cultural attributes in the organisation to implement social sustainability supply chain management practices that go beyond monitoring suppliers to behavioural changes in the supply chain with implications beyond the dyad of buyer and supplier to lower tier suppliers and the community surrounding the supply chain.

Originality/value
– This is the first time, to the authors’ knowledge, that cultural and entrepreneurial variables have been tested for social sustainability supply chain practices, giving them new insights into how and why social sustainability supply chain practices are adopted.

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Electric vehicles (EVs) and hybrid EVs are the way forward for green transportation and for establishing low-carbon economy. This paper presents a split converter-fed four-phase switched reluctance motor (SRM) drive to realize flexible integrated charging functions (dc and ac sources). The machine is featured with a central-tapped winding node, eight stator slots, and six rotor poles (8/6). In the driving mode, the developed topology has the same characteristics as the traditional asymmetric bridge topology but better fault tolerance. The proposed system supports battery energy balance and on-board dc and ac charging. When connecting with an ac power grid, the proposed topology has a merit of the multilevel converter; the charging current control can be achieved by the improved hysteresis control. The energy flow between the two batteries is balanced by the hysteresis control based on their state-of-charge conditions. Simulation results in MATLAB/Simulink and experiments on a 150-W prototype SRM validate the effectiveness of the proposed technologies, which may provide a solution to EV charging issues associated with significant infrastructure requirements.

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An experimental investigation is carried out to verify the feasibility of using an instrumented vehicle to detect and monitor bridge dynamic parameters. The low-cost method consists of the use of a moving vehicle fitted with accelerometers on its axles. In the laboratory experiment, the vehicle–bridge interaction model consists of a scaled two-axle vehicle model crossing a simply supported steel beam. The bridge model also includes a scaled road surface profile. The effects of varying the vehicle model configuration and speed are investigated. A finite element beam model is calibrated using the experimental results, and a novel algorithm for the identification of global bridge stiffness is validated. Using measured vehicle accelerations as input to the algorithm, the beam stiffness is identified with a reasonable degree of accuracy.

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This study presents a vibration-based health monitoring of short span bridges by
an inspection vehicle. How to screen health condition of short span bridges in terms of the
drive-by bridge inspection is described. Feasibility of the drive-by bridge inspection is
investigated through a scaled laboratory moving vehicle experiment. The feasibility of using an
instrumented vehicle to detect the natural frequency and changes in structural damping of a
model bridge is observed. Observations also demonstrate possibility of diagnosis of bridges by
comparing patterns of identified dynamic parameters of bridges through a periodical
monitoring. It is confirmed that the method for damage identification under a moving vehicle
identifies the damage location and severity well.

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Many of the bridges currently in use worldwide are approaching the end of their design lives. However, rehabilitating and extending the lives of these structures raises important safety issues. There is also a need for increased monitoring which has considerable cost implications for bridge management systems. Existing structural health monitoring (SHM) techniques include vibration-based approaches which typically involve direct instrumentation of the bridge and are important as they can indicate the deterioration of the bridge condition. However, they can be labour intensive and expensive. In the past decade, alternative indirect vibration-based approaches which utilise the response of a vehicle passing over a bridge have been developed. This paper investigates such an approach; a low-cost approach for the monitoring of bridge structures which consists of the use of a vehicle fitted with accelerometers on its axles. The approach aims to detect damage in the bridge while obviating the need for direct instrumentation of the bridge. Here, the effectiveness of the approach in detecting damage in a bridge is investigated using a simplified vehicle-bridge interaction (VBI) model in theoretical simulations and a scaled VBI model in a laboratory experiment. In order to identify the existence and location of damage, the vehicle accelerations are recorded and processed using a continuous Morlet wavelet transform and a damage index is established. A parametric study is carried out to investigate the effect of parameters such as the bridge span length, vehicle speed, vehicle mass, damage level and road surface roughness on the accuracy of results.

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The myriad of technologies and protocols working at different layers pose significant security challenges in the upcoming Internet of Things (IoT) paradigm. Security features and needs vary from application to application and it is layer specific. In addition, security has to consider the constraints imposed by energy limited sensor nodes and consider the specific target application in order to provide security at different layers. This paper analyses current standardization efforts and protocols. It proposes a generic secured network topology for IoT and describes the relevant security challenges. Some exploitation examples are also provided.

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Integrated energy system and Energy Internet are two hot topics in the field of energy. In this paper, these two concepts and their focuses are summarized and analyzed. Typical research in the areas of integrated energy system and Energy Internet is reviewed. The research concerns and technologies of these two concepts are then outlined respectively. The differences and similarities of these two concepts and their future development are discussed.

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This paper investigates a low-cost wavelet-based approach for the preliminary monitoring of bridge structures, consisting of the use of a vehicle fitted with accelerometers on its axles. The approach aims to reduce the need for direct instrumentation of the bridge. A time-frequency analysis is carried out in order to identify the existence and location of damage from vehicle accelerations. Firstly, in theoretical simulations, a simplified vehicle-bridge interaction model is used to investigate the effectiveness of the approach. A number of damage indicators are evaluated and compared. A range of parameters such as the bridge span, vehicle speed, damage level and location, signal noise and road roughness are varied in simulations. Secondly, a scaled laboratory experiment is carried out to validate the results of the theoretical analysis and assess the ability of the selected damage indicators to detect changes in the bridge response from vehicle accelerations.