Academic literature on the topic 'Vehicle size classes'
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Journal articles on the topic "Vehicle size classes"
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Zhang, T., G. Vosselman, and S. J. Oude Elberink. "VEHICLE RECOGNITION IN AERIAL LIDAR POINT CLOUD BASED ON DYNAMIC TIME WARPING." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2/W4 (September 13, 2017): 193–98. http://dx.doi.org/10.5194/isprs-annals-iv-2-w4-193-2017.
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A two-step vehicle recognition method from an aerial Lidar point cloud is proposed in this paper. First, the Lidar point cloud is segmented using the region-growing algorithm with vehicle size limitation. Then the vehicle is recognized according to the profile shape based on dynamic time warping. The proposed method can detect vehicles parking under trees in an urban scene, and classifies the vehicles into different classes. The vehicle location, orientation, parking direction and size can also be determined. The experimental result based on a real urban Lidar point cloud shows that the proposed method can correctly recognize 95.1 % of vehicles.
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Li, Bo, Zhi Yuan Zeng, and Ji Xiong Chen. "Vehicle Classification and Tracking Based on Particle Swarm Optimization and Meanshift." Advanced Materials Research 121-122 (June 2010): 417–22. http://dx.doi.org/10.4028/www.scientific.net/amr.121-122.417.
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Vehicle classification and tracking is considered as one of the most challenging problems in the field of pattern recognition. In this paper, Particle Swarm Optimization (PSO) based method is exploited to recognize vehicle classes. Vehicle features, such as vehicle size, shape information, contour information are extracted. Each vehicle class is encoded as a centroid with multidimensional feature and PSO is employed to search the optimal position for each class centroid based on fitness function. After vehicle classification, an improved meanshift algorithm is presented for vehicle tracking. The algorithm’s evaluations on video image series, moving vehicle detection, vehicle classification and tracking are respectively conducted. The results show that PSO ensures a promising and stable performances in recognizing these vehicle classes, and the improved meanshift algorithm can achieve accuracy and real-time for tracking moving vehicles.
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González Palencia, Juan C., Van Tuan Nguyen, Mikiya Araki, and Seiichi Shiga. "The Role of Powertrain Electrification in Achieving Deep Decarbonization in Road Freight Transport." Energies 13, no. 10 (May 13, 2020): 2459. http://dx.doi.org/10.3390/en13102459.
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Decarbonizing road freight transport is difficult due to its reliance on fossil fuel internal combustion engine vehicles (ICEVs). The role of powertrain electrification in achieving deep decarbonization in road freight transport was studied using a vehicle stock turnover model, focusing on Japan. Twelve vehicle types were considered; combining four powertrains, ICEV, hybrid electric vehicle (HEV), battery electric vehicle (BEV) and fuel cell electric vehicle (FCEV); and three vehicle size classes, normal, compact and mini-sized vehicles. A scenario-based approach was used; considering a Base scenario, and three alternative scenarios targeting powertrain electrification. Between 2012 and 2050, tank to wheel CO2 emissions decrease 42.8% in the Base scenario, due to the reduction of vehicle stock, the improvement of vehicle fuel consumption and the adoption of HEVs. Diffusion of FCEVs in normal vehicles and BEVs in compact and mini-sized vehicles achieves the largest tank to wheel CO2 emissions reductions, up to 44.6% compared with the 2050 baseline value. The net cash flow is positive over the whole time horizon, peaking at 6.7 billion USD/year in 2049 and reaching 6.6 billion USD/year by 2050. Powertrain electrification is not enough to achieve any of the CO2 emissions reduction targets in road freight transport.
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Pejić, Goran, Franjo Bijelić, Goran Zovak, and Zoran Lulić. "Model for Calculating Average Vehicle Mileage for Different Vehicle Classes Based on Real Data: A Case Study of Croatia." PROMET - Traffic&Transportation 31, no. 2 (April 19, 2019): 213–22. http://dx.doi.org/10.7307/ptt.v31i2.3043.
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Mileage data collected via surveys based on self-estimation, reports from garages and other sources which use estimations are rough estimates and differ greatly from the actual mileage. Vehicle mileage is a major factor in emission calculations and needs to be as accurate as possible to obtain reliable emission models. Odometer readings are collected annually at the periodic technical inspection in Croatia. Average mileage data were analyzed for vehicles up to 20 years of age in 2017. Vehicles were classified by curb weight and fuel type. Such classification proved to follow driver behavior and the intended purpose of the vehicle. For each vehicle class, the model was applied using the vehicle age and its population size as inputs for calculating average mileage. Real data shows that vehicles in Croatia considerably exceed the estimated mileage in the years following the first registration of the vehicle and that they cannot be compared to data collected in other studies based on estimations. The difference lies in the covered mileage after vehicles reach ten years of age. The outcome of this study has resulted in a model for calculating average vehicle mileage. The model is suitable for use in various analyses for Croatia or for countries with similar driving habits and economic status now and for years to come.
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Sterne, Kevin T., Joseph M. Ernst, Deirdre K. Kilcoyne, Alan J. Michaels, and Geffrey Moy. "Tire Pressure Monitoring System Sensor Radio Frequency Measurements for Privacy Concerns." Transportation Research Record: Journal of the Transportation Research Board 2643, no. 1 (January 2017): 34–44. http://dx.doi.org/10.3141/2643-05.
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Since the National Highway Traffic Safety Administration mandated the incorporation of tire pressure monitoring systems (TPMSs) in all newly produced passenger vehicles, most vehicle manufacturers have adopted direct pressure measurement. Direct TPMS sensors embedded in each tire require a wireless radio frequency (RF) communications link that broadcasts tire status to the vehicle once per minute from each tire when at speed. Each TPMS message communicates benign information that includes pressure and temperature as well as a static unique identifier that may be exploited, which raises concerns about privacy and spoofing. To focus on concerns related to the TPMS-RF interface, vehicle motion simulations were integrated with live propagation modeling measurements from three classes of passenger vehicles: subcompact car, full-size sedan, and full-size pickup. The RF link and channel models for this TPMS interface with the vehicle resulted in surprisingly long ranges away from the vehicle for the radiation of the unique identifiers. A TPMS sensor redesign could use the proposed RF channel propagation measurements to change the directions of signal propagation while reducing battery consumption by the TPMS sensor (which is affected primarily by RF transmission).
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Jacobsen, Mark R. "Fuel Economy and Safety: The Influences of Vehicle Class and Driver Behavior." American Economic Journal: Applied Economics 5, no. 3 (July 1, 2013): 1–26. http://dx.doi.org/10.1257/app.5.3.1.
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Fuel economy standards change the composition of the vehicle fleet, influencing accident safety. The direction and size of the effect depend on the combination of vehicles in the fleet. I provide empirical estimates of vehicle safety across classes, accounting for unobserved driving behavior and selection. I apply the model to the present structure of US fuel economy standards, accounting for shifts in the composition of vehicle ownership, and estimate an adverse safety effect of 33 cents per gallon of gasoline saved. I show how two alternative regulatory provisions fully offset this effect, producing a nearzero change in accident fatalities. (JEL D12, L51, L62, Q48, R41)
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Zeng, Zhi Yuan, Bo Li, Xiao Jun Tan, and Jian Zhong Zhou. "Moving Vehicle Classification Using Cloud Model." Key Engineering Materials 467-469 (February 2011): 2123–28. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.2123.
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In this paper, we proposed a vehicle classification algorithm based on cloud model. Cloud model is a new theory which can express the relationship between randomness and fuzziness. Vehicle features, such as vehicle size, shape information, contour information and edge information are extracted for cloud model. Each vehicle class is expressed through cloud model parameters, such as Ex (expectation), En (entropy), with multi-dimensional feature. And cloud classification model is employed to judge the optimal class for each vehicle. Furthermore, attribute similarity is introduced to judge the weight of each feature in classification. Decision tree classifier is utilized for classification. The algorithm’s evaluations on video image series, the results show that cloud model ensures a promising and stable performance in recognizing these vehicle classes, and the algorithm can achieve accuracy and real-time.
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Ullah, Shan, and Deok-Hwan Kim. "Lightweight Driver Behavior Identification Model with Sparse Learning on In-Vehicle CAN-BUS Sensor Data." Sensors 20, no. 18 (September 4, 2020): 5030. http://dx.doi.org/10.3390/s20185030.
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This study focuses on driver-behavior identification and its application to finding embedded solutions in a connected car environment. We present a lightweight, end-to-end deep-learning framework for performing driver-behavior identification using in-vehicle controller area network (CAN-BUS) sensor data. The proposed method outperforms the state-of-the-art driver-behavior profiling models. Particularly, it exhibits significantly reduced computations (i.e., reduced numbers both of floating-point operations and parameters), more efficient memory usage (compact model size), and less inference time. The proposed architecture features depth-wise convolution, along with augmented recurrent neural networks (long short-term memory or gated recurrent unit), for time-series classification. The minimum time-step length (window size) required in the proposed method is significantly lower than that required by recent algorithms. We compared our results with compressed versions of existing models by applying efficient channel pruning on several layers of current models. Furthermore, our network can adapt to new classes using sparse-learning techniques, that is, by freezing relatively strong nodes at the fully connected layer for the existing classes and improving the weaker nodes by retraining them using data regarding the new classes. We successfully deploy the proposed method in a container environment using NVIDIA Docker in an embedded system (Xavier, TX2, and Nano) and comprehensively evaluate it with regard to numerous performance metrics.
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Richardson, Brian, Carol A. Rolando, Mark O. Kimberley, and Tara M. Strand. "Spray Application Efficiency from a Multi-Rotor Unmanned Aerial Vehicle Configured for Aerial Pesticide Application." Transactions of the ASABE 62, no. 6 (2019): 1447–53. http://dx.doi.org/10.13031/trans.13509.
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HighlightsThe swath pattern was measured from an Agras MG-1 UAV spraying fine and extra-coarse droplet spectra.The recommended lane separation of 3.6 m did not differ for the two droplet size classes tested in this study.The applied spray deposited within the swath was higher with extra-coarse (>90%) than with fine (73%) droplets.There was potential for substantial downwind drift with fine droplets, even when flying close to the ground at low speed.Abstract. While there is increasing interest in the use of small, multi-rotor UAVs for application of agrichemicals, there is also uncertainty about their performance. Consequently, the purpose of this study was to quantify the performance of an Agras MG-1 with modified nozzle positions that, at the time of writing, was being used for commercial spraying in New Zealand. The approach was to release spray from the UAV along a single 50 m line. Spray deposits were measured using horizontal collectors placed on the ground in three 15 m transects centered on, and perpendicular to, the flight line. Airborne deposits were measured with a 10 m mast that supported spherical samplers at 1 m vertical intervals. Analysis of deposition data was undertaken to quantify factors influencing overall swath pattern variability, lane separation associated with a coefficient of variation (CV) of deposition of 30%, and spray application efficiency, which is the proportion of applied spray deposited within the swath. For two droplet size classes (extra-coarse and fine), the lane separation associated with a CV of 30% was about 3.6 m, with no significant effect of droplet size. This is a surprising result and may reflect the relatively small range of environmental conditions experienced during the field tests, including wind speed, which was relatively low for all tests. We speculate that this result may also be a consequence of the strong downwash. The swath width was positively correlated with wind speed. Spray efficiency was shown to be high (>90%) for the extra-coarse droplets but dropped significantly (73%) with the fine droplet spectrum. Combining in-swath deposition with the amount of airborne spray sampled in a 10 m vertical profile close to the edge of the swath accounted for 98.0% of the spray released with the extra-coarse spectrum but only 88.6% of the spray with the fine droplet spectrum. These results highlight that even with UAVs flying relatively close to the ground at a low forward speed, there is potential for substantial drift downwind of the swath when using smaller droplet size classes. Overall, the swath pattern was reasonably consistent across the two droplet size classes and for the narrow range of operational and meteorological conditions tested. Keywords: Aerial spraying, Pesticides, Spray application efficiency, Spray deposition, Swath pattern, UAV, Unmanned aerial vehicle.
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Lesser, Lawrence M. "Delving Deeper: Sizing Up Class Size: A Deeper Classroom Investigation of Central Tendency." Mathematics Teacher 103, no. 5 (December 2009): 376–80. http://dx.doi.org/10.5951/mt.103.5.0376.
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Being able to select, use, and interpret measures of center is expected of all secondary students (NCTM 2000, 2006). Discussing average class size can be a motivational vehicle for exploring this topic because students (and teachers) at all grade levels notice when they have significantly bigger classes and high school juniors and seniors see average class size touted in the publicity brochures they receive from colleges. Also, educators, administrators, policy makers, and parents are concerned about the impact class size may have on student achievement and equity (e.g., Finn, Gerber, and Boyd-Zaharias 2005; Nye, Hedges, and Konstantopoulos 2004; Pong and Pallas 2001). Finally, using situations that readily yield results that students initially find counterintuitive can be motivating (Lesser 1998).
Dissertations / Theses on the topic "Vehicle size classes"
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Vašíček, Jiří. "Kompatibilita vozidel při čelním střetu." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-232731.
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Thesis deals with the compatibility of vehicles in a frontal collision. The first section discusses about compatibility from different views. There are the physical processes used in the mechanics of impact. The second part is focused on solving the compatibility of vehicles in a frontal collision by crash analysis using the finite element method. Firstly there are described collisions of vehicles from different vehicle classes (small cars, lower middle class, Pick up / SUV) into the fixed barrier by the US NCAP. Furthermore there are simulated head-on collisions of vehicles from different vehicle classes. In the end there is shown the possibility of using data from crash tests to determine the EES.
Book chapters on the topic "Vehicle size classes"
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Utamima, Amalia, Torsten Reiners, Amir Ansaripoor, and Hasan Seyyedhasani. "The Agricultural Routing Planning in Field Logistics." In Contemporary Approaches and Strategies for Applied Logistics, 261–83. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-5273-4.ch010.
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The agricultural sector is facing the need to gain a higher yield on their fields while optimising their operations to stay competitive and satisfy the continuously increasing demand for produce. Cost reductions can be achieved by increasing the effective field size and reducing the operations without gain (e.g., driving longer distance to harvest the field). The agricultural routing planning (ARP) problem represents a specialisation of the travelling salesman problem (TSP) or vehicle routing problem (VRP) with focus on the agricultural operations and considerations of the field and vehicles configurations. In addition, various adaptations of the problem can be found in the literature that define a new problem class with specialised optimisation needs. This chapter introduces the ARP and reviews the past and current research and developments.
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Kaiwartya, Omprakash, Pawan Kumar Tiwari, Sushil Kumar, and Mukesh Prasad. "Dynamic Vehicle Routing Solution in the Framework of Nature-Inspired Algorithms." In Designing and Implementing Global Supply Chain Management, 36–50. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9720-1.ch003.
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Vehicle Routing Problem (VRP), a well-known combinatorial optimization problem had been presented by Dantzing and Hamser in 1959. The problem has taken its inspiration from the transport field. In real field environment, a lot of variants of the problem exist that actually belongs to the class of NP-hard problem. Dynamic Vehicle routing problem (DVRP) is one of the variant of VRP that varies with respect to time. In DVRP, new customer orders appear over time and new route must be reconfigured at any instantaneous time. Although, some exact algorithms such as dynamic programming methods, branch and bound etc. can be applied to find the optimal route of a smaller size VRP. But, These Algorithms fail to give the solution of existed model of VRP in real field environment under given real time constraints. Courier services, dial a ride services and express mail delivery etc. are the few examples of real field environment problems that can be formulated in the form of DVRP. In this chapter, A novel variants of DVRP named as DVRP with geographic ranking (DVRP-GR) has been proposed. In DVRP-GR, geographical ranking, customer ranking, service time, expected reachability time, customer satisfaction level have been optimized. A solution of DVRP-GR using seed based particle swarm optimization (S-DVRS-PSO) has been also proposed. The simulations have been performed using customized simulator developed in C++ environment. The data sets used in the simulations are OMK-01, OMK-02 and OMK-03 generated in real vehicular environment. The solution of the proposed algorithm has been compared with the randomized solution technique. Analysis of the simulation results confirms the effectiveness of the proposed solution in terms of various parameters considered viz. number of vehicles, expected reachability time, profit and customer satisfaction.
Conference papers on the topic "Vehicle size classes"
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Sturari, Mirco, Luca Esposto, Christian Spurio, Domenico Tigano, Adriano Mancini, and Primo Zingaretti. "Vehicle Tracking and Classification From Videos Under Illumination Changes and Occlusions." In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/detc2017-68004.
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Vehicle tracking and classification algorithms that remain robust under illuminations changes and occlusions remain a challenging task for vehicle recognition systems. A vehicle which reappears in the scene after disappearing behind an obstacle or a bigger vehicle has to re-obtain the previous identification number assigned by the system. In other circumstances, two or more vehicles overlapping each other are recognized by the system as a single entity: for this reason, after splitting, the system has to reassign pending identification numbers to the respective vehicles. In this paper we propose a three steps (vehicle identification with removal of headlight reflections, tracking with occlusion management and classification with size and speed estimation) algorithm operating in presence of illumination changes, reflections and occlusions. The experimental results obtained by processing a video recorded from a static camera show that the approach is able to successfully manage occlusions in over 90% of cases and to satisfactory classify vehicles into four classes, depending on their length/dimension.
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Sakamoto, Haruo, Takashi Uchino, Toru Kaino, Tatsuro Sawada, and Masaaki Yokoyama. "Capstone Design and Manufacture of Hand–Made Small-Sized Electric Vehicle." In ASME 2001 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/detc2001/ied-21220.
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Abstract This paper describes an engineering education attempt in a synthesis class during the 4th year. Since the Kochi University of Technology was inaugurated in April, 1997, engineering education trials had been conducted in the past 4 years. In 1997, 3 student teams participated in an eco-power race held in Kochi, Japan, with hand-made ecological vehicles. In the summer, 1998, three teams participated in the Shikoku Electric Vehicle Rally using light weight vehicles converted into electric cars. The synthesis class was performed based on such past engineering activities out of class. In order to provide an active learning opportunity, a synthetic learning environment is needed rather than just teaching in classes. Manufacturing is also considered to be of great importance for mechanical engineering as well as the basic sciences such as mathematics and physics. As a capstone learning course, a team of four students in the laboratory tried to design and manufacture a hand-made small-sized electric vehicle.
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Samaha, Randa Radwan, Priyaranjan Prasad, Dhafer Marzougui, Chongzhen Cui, Cing-Dao (Steve) Kan, and Azim Eskandarian. "An Integrated Modeling Method to Evaluate Fleet Safety Performance of New Vehicle Designs." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-66285.
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A methodology for Evaluating Fleet, i.e., self and partner, Protection (EFP) of new vehicle designs is developed through a systems modeling approach driven by structural and occupant modeling and real world crash and full scale test data. The EFP methodology consists of a virtual model simulating the real world crash environment (i.e., different types of vehicles, impact velocities, impact directions, impact types, etc.). A concept or new vehicle design could be introduced into this model to evaluate the safety of its occupants and those of other vehicles with which it is involved in crashes. The initial implementation of EFP methodology is to frontal crashes where the modeled crash configurations are derived from a new crash taxonomy based on real world structural engagement. Simulation data to drive the methodology is obtained from finite element structural models of the vehicles. Occupant responses are based on three dimensional articulated rigid body models of the occupant and the passenger compartment. The occupant is restrained by seat belts and airbags and the structural deformations and kinematics of the passenger compartment needed to drive the occupant models are predicted by the finite element structural models. Both the structural and the occupant models are subjected to validation and robustness checks for the modeled crash configurations. The aggregate of injury risk across vehicle classes, impact speeds, occupant sizes, and crash configurations, weighted by relative frequency of the specific event in real world crashes, is used as a measure of overall societal safety. Results from a proof-of-concept application are presented.
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Pendleton, Scott Drew, Hans Andersen, Xiaotong Shen, You Hong Eng, Chen Zhang, Hai Xun Kong, Wei Kang Leong, Marcelo H. Ang, and Daniela Rus. "Multi-class autonomous vehicles for mobility-on-demand service." In 2016 IEEE/SICE International Symposium on System Integration (SII). IEEE, 2016. http://dx.doi.org/10.1109/sii.2016.7843999.
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Pritchard, Ewan, and Richard R. Johnson. "Technical Performance Modeling of Hybrid and Plug-In Hybrid Electric School Buses Using ADVISOR." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79530.
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The hybrid electric vehicle is changing the automotive market at an impressive rate. While not as highly publicized, the transit bus market is being transformed at an equally great rate. As these markets move forward, the school bus market remains largely unchanged. As an unchanged market, there is still the opportunity to optimize a hybrid vehicle platform for school buses. This study models an existing class C school bus and investigates the potential of both series and parallel hybrids to reduce fuel consumption and emissions. The primary focus of this study is to investigate the potential benefits of adding an electric grid interconnection to hybrid electric school buses, allowing them to add to the hybrid potential to a pre-charged battery pack. These vehicles are known as plug-in hybrids. The school bus models shown in this paper were generated in a Matlab/Simulink-based program developed by NREL called ADVISOR. ADVISOR is used by vehicle manufacturers as a tool to experiment with different vehicle configurations. In this study both a generic series hybrid and a generic parallel hybrid are generated and used in both charge-sustaining and charge-depleting scenarios with varying sizes of battery packs to increase the “grid energy.” The results of each model are presented by fuel economy and emissions reductions taking into account the power plant emissions and electricity costs. The results of the study show that by adding a plug-in connection to existing hybrids, significant savings can be achieved, both in fuel costs and in overall emissions. By analyzing the emissions at the power plant level and at the vehicle level we show that emission of NOx, Particulate Matter and Carbon Dioxide can all be reduced while saving on fuel costs. This study also shows that some models of traditional hybrid can be operated as plug-in models with little or no change to the system to gain significant benefit from the initial charge.
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Li, Yan, and Andrew Alleyne. "A Generalized Robust Control Framework Utilizing Dimensional Analysis." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-82191.
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Most engineered systems designed under heavy external constraints share similar dynamics. Using a dimensionless model as system representation, a dimensionless robust controller can be designed and implemented for a class of dynamically similar systems that are different in size. Dimensionless transformations of time scale, inputs and outputs determine a nominal plant model and plant-to-plant uncertainties in a dimensionless form. Using parameter-dependent normalization, a normalized dimensionless model can be derived that has low level of plant-to-plant uncertainties. The benefit of this dimensional analysis is demonstrated by the analysis of a passenger vehicle model for yaw rate control with a database consisting of 36 sets of vehicle data.
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Krishnan, Shankar, Steve Leith, and Terry Hendricks. "Enhanced Gas-Side Heat Transfer in Rectangular Micro-Honeycombs." In ASME 2012 6th International Conference on Energy Sustainability collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/es2012-91223.
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Gas and air-side heat transfer is ubiquitous throughout many technological sectors, including HVAC (heating, ventilating, and air conditioning) systems, thermo-electric power generators and coolers, renewable energy, electronics and vehicle cooling, and forced-draft cooling in the petrochemical and power industries. The poor thermal conductivity and low heat capacity of air causes air-side heat transfer to typically dominate heat transfer resistance even with the use of extended area structures. In this paper, we report design, analysis, cost modeling, fabrication, and performance characterization of micro-honeycombs for gas-side heat transfer augmentation in thermoelectric (TE) cooling and power systems. Semi-empirical model aided by experimental validation was undertaken to characterize fluid flow and heat transfer parameters. We explored a variety of polygonal shapes to optimize the duct shape for air-side heat transfer enhancement. Predictions using rectangular micro-honeycomb heat exchangers, among other polygonal shapes, suggest that these classes of geometries are able to provide augmented heat transfer performance in high-temperature energy recovery streams and low-temperature cooling streams. Based on insight gained from theoretical models, rectangular micro-honeycomb heat exchangers that can deliver high performance were fabricated and tested. High- and low-cost manufacturing prototype designs with different thermal performance expectations were fabricated to explore the cost-performance design domain. Simple metrics were developed to correlate heat transfer performance with heat exchanger cost and weight and define optimum design points. The merits of the proposed air-side heat transfer augmentation approach are also discussed within the context of relevant thermoelectric power and cooling systems.
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Xing, Yihan, Kristian Fotland, and Muk Chen Ong. "OpenModelica Modelling of the Thruster in a Compact Subsea Work-Class Remotely Operated Vehicle." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-96839.
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Abstract Thrusters are vital for the functionalities of remotely operated vehicles (ROVs). The development of thruster design is a trade-off between cost, thrust force, physical weight and size. A six degree of freedom model is created in OpenModelica to investigate the vibrations and bearing responses in thruster systems. The model consists of a marine propeller, a shaft, and two bearings. The propeller used is based on the Wageningen B-screw propeller series. The hydrodynamic added mass and damping forces are calculated from empirical equations based on open water tests and are functions of the propeller geometry, rotational speed and fluid density. Meanwhile, the mean thrust and torque are obtained from open water test data of the relevant propeller and are used to calculate the dynamic forces and moments from the marine propeller. Displacements in the axial, horizontal, and vertical directions are calculated and used to investigate vibration amplitudes and bearing life. Initial steady-state simulations show that the bearing life of the bearings in the thruster is found to be highly dependent on the axial load acting on the bearing, i.e., the thrust force. Moreover, if the propeller is not balanced then high centrifugal forces can occur and result in severe forces in the radial direction which can be of concern regarding the bearing life.
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Rodgers, C. "Affordable Smaller Turbofans." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68042.
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Smaller smarter un-manned air vehicles (UAV’s) and missiles are being proposed and developed to function in a variety of roles previously performed by larger manned aircraft and limited range missiles. The endurance and stealth demanded of such advanced vehicles requires small turbofan engines possessing relatively higher power density combined with increased thermal efficiency. It is shown that these two major performance related criteria are indirectly related to improved affordability for a specific turbofan design configuration. Changing the design configuration by implementing lower component count and flowpath simplification however is an alternate trade-off route to improved affordability, albeit at a slight performance decrement. As an example the classic two spool (2SC) turbofan with concentric shafting for the inner spool is the engine of choice for extended range applications, but can present shaft dynamic and bearing lubrication mechanical design concerns as size is reduced and core rotational speeds approach and exceed 100Krpm. Preliminary design features of two alternate non concentric drive small turbofan flowpath candidates are presented, neither of which can match the full performance capability of the classic two spool concentric drive turbofan, yet they potentially offer several affordability virtues, inasmuch as lower component count, reduced cost, higher reliability, oil less lubrication, and electric driven accessories.
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Ahn, Sang-Yeoul, Ui-Sik Jeon, and Byung-Ki Ahn. "Development of the BOP Bench System for PEM Fuel Cell Vehicles at Hyundai MOBIS." In ASME 2005 3rd International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2005. http://dx.doi.org/10.1115/fuelcell2005-74150.
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We have developed a BOP test bench of 80kW-class PEMFC systems to evaluate the performance and optimize the size of the core components of the BOP for fuel cell vehicles. The BOP components including heat exchangers, water pumps, deionizers, and compressors are connected to provide the reactant gases and the coolant to a mock-up stack which is designed to reasonably simulate the electrochemical phenomena of an actual stack. Sensors and actuators are installed between the inlets and outlets of the components, and are connected to the data acquisition and control systems to control pressure, temperature, flow rate and humidity of the used fluids.
Reports on the topic "Vehicle size classes"
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Burnham, Andrew, David Gohlke, Luke Rush, Thomas Stephens, Yan Zhou, Mark Delucchi, Alicia Birky, et al. Comprehensive Total Cost of Ownership Quantification for Vehicles with Different Size Classes and Powertrains. Office of Scientific and Technical Information (OSTI), April 2021. http://dx.doi.org/10.2172/1780970.
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Jorgensen, Frieda, Andre Charlett, Craig Swift, Anais Painset, and Nicolae Corcionivoschi. A survey of the levels of Campylobacter spp. contamination and prevalence of selected antimicrobial resistance determinants in fresh whole UK-produced chilled chickens at retail sale (non-major retailers). Food Standards Agency, June 2021. http://dx.doi.org/10.46756/sci.fsa.xls618.
Full textAbstract:
Campylobacter spp. are the most common bacterial cause of foodborne illness in the UK, with chicken considered to be the most important vehicle for this organism. The UK Food Standards Agency (FSA) agreed with industry to reduce Campylobacter spp. contamination in raw chicken and issued a target to reduce the prevalence of the most contaminated chickens (those with more than 1000 cfu per g chicken neck skin) to below 10 % at the end of the slaughter process, initially by 2016. To help monitor progress, a series of UK-wide surveys were undertaken to determine the levels of Campylobacter spp. on whole UK-produced, fresh chicken at retail sale in the UK. The data obtained for the first four years was reported in FSA projects FS241044 (2014/15) and FS102121 (2015 to 2018). The FSA has indicated that the retail proxy target for the percentage of highly contaminated raw whole retail chickens should be less than 7% and while continued monitoring has demonstrated a sustained decline for chickens from major retailer stores, chicken on sale in other stores have yet to meet this target. This report presents results from testing chickens from non-major retailer stores (only) in a fifth survey year from 2018 to 2019. In line with previous practise, samples were collected from stores distributed throughout the UK (in proportion to the population size of each country). Testing was performed by two laboratories - a Public Health England (PHE) laboratory or the Agri-Food & Biosciences Institute (AFBI), Belfast. Enumeration of Campylobacter spp. was performed using the ISO 10272-2 standard enumeration method applied with a detection limit of 10 colony forming units (cfu) per gram (g) of neck skin. Antimicrobial resistance (AMR) to selected antimicrobials in accordance with those advised in the EU harmonised monitoring protocol was predicted from genome sequence data in Campylobacter jejuni and Campylobacter coli isolates The percentage (10.8%) of fresh, whole chicken at retail sale in stores of smaller chains (for example, Iceland, McColl’s, Budgens, Nisa, Costcutter, One Stop), independents and butchers (collectively referred to as non-major retailer stores in this report) in the UK that are highly contaminated (at more than 1000 cfu per g) with Campylobacter spp. has decreased since the previous survey year but is still higher than that found in samples from major retailers. 8 whole fresh raw chickens from non-major retailer stores were collected from August 2018 to July 2019 (n = 1009). Campylobacter spp. were detected in 55.8% of the chicken skin samples obtained from non-major retailer shops, and 10.8% of the samples had counts above 1000 cfu per g chicken skin. Comparison among production plant approval codes showed significant differences of the percentages of chicken samples with more than 1000 cfu per g, ranging from 0% to 28.1%. The percentage of samples with more than 1000 cfu of Campylobacter spp. per g was significantly higher in the period May, June and July than in the period November to April. The percentage of highly contaminated samples was significantly higher for samples taken from larger compared to smaller chickens. There was no statistical difference in the percentage of highly contaminated samples between those obtained from chicken reared with access to range (for example, free-range and organic birds) and those reared under standard regime (for example, no access to range) but the small sample size for organic and to a lesser extent free-range chickens, may have limited the ability to detect important differences should they exist. Campylobacter species was determined for isolates from 93.4% of the positive samples. C. jejuni was isolated from the majority (72.6%) of samples while C. coli was identified in 22.1% of samples. A combination of both species was found in 5.3% of samples. C. coli was more frequently isolated from samples obtained from chicken reared with access to range in comparison to those reared as standard birds. C. jejuni was less prevalent during the summer months of June, July and August compared to the remaining months of the year. Resistance to ciprofloxacin (fluoroquinolone), erythromycin (macrolide), tetracycline, (tetracyclines), gentamicin and streptomycin (aminoglycosides) was predicted from WGS data by the detection of known antimicrobial resistance determinants. Resistance to ciprofloxacin was detected in 185 (51.7%) isolates of C. jejuni and 49 (42.1%) isolates of C. coli; while 220 (61.1%) isolates of C. jejuni and 73 (62.9%) isolates of C. coli isolates were resistant to tetracycline. Three C. coli (2.6%) but none of the C. jejuni isolates harboured 23S mutations predicting reduced susceptibility to erythromycin. Multidrug resistance (MDR), defined as harbouring genetic determinants for resistance to at least three unrelated antimicrobial classes, was found in 10 (8.6%) C. coli isolates but not in any C. jejuni isolates. Co-resistance to ciprofloxacin and erythromycin was predicted in 1.7% of C. coli isolates. 9 Overall, the percentages of isolates with genetic AMR determinants found in this study were similar to those reported in the previous survey year (August 2016 to July 2017) where testing was based on phenotypic break-point testing. Multi-drug resistance was similar to that found in the previous survey years. It is recommended that trends in AMR in Campylobacter spp. isolates from retail chickens continue to be monitored to realise any increasing resistance of concern, particulary to erythromycin (macrolide). Considering that the percentage of fresh, whole chicken from non-major retailer stores in the UK that are highly contaminated (at more than 1000 cfu per g) with Campylobacter spp. continues to be above that in samples from major retailers more action including consideration of interventions such as improved biosecurity and slaughterhouse measures is needed to achieve better control of Campylobacter spp. for this section of the industry. The FSA has indicated that the retail proxy target for the percentage of highly contaminated retail chickens should be less than 7% and while continued monitoring has demonstrated a sustained decline for chickens from major retailer stores, chicken on sale in other stores have yet to meet this target.