scholarly journals Criterion for evaluating vehicle performance

2019 ◽  
Vol 78 (2) ◽  
pp. 96-99
Author(s):  
E. E. KOSSOV ◽  
V. V. ASABIN ◽  
A. G. SILYUTA ◽  
L. E. L. E. KOSSOVA
Keyword(s):  
Energy Efficiency ◽  
Autonomous Vehicle ◽  
Operating Conditions ◽  
Railway Transport ◽  
Vehicle Performance ◽  
Actual Performance ◽  
Operational Energy ◽  
Energy Efficiency Indicator ◽  
Technical Specifications ◽  
And Performance

The article proposes to evaluate the efficiency of an autonomous vehicle, taking into account not only the energy consumption for motion, but also the time of motion, i. e. both factors — efficiency and performance — should be taken into account. As a criterion for evaluating the efficiency of vehicles, authors propose the multiplication of efficiency on performance — the energy efficiency indicator (EEI). The best will be the vehicle with the highest EEI. The indicator should be calculated according to the specified technical characteristics of the vehicle laid down in the technical specifications. This criterion is suitable both for the evaluation of the vehicle during the design and during operation. At the same time, it is possible to evaluate and compare the EEI of technical vehicles not only of railway transport. The article presents the criterion values for water, rail and air transport. Proposed criterion makes it possible to evaluate the change in vehicle efficiency over time due to technical progress. Since 1953, the energy efficiency of a diesel locomotive has increased almost 3 times. To calculate the operational energy efficiency, it is necessary to obtain data on the actual performance of the vehicle. On railway transport, this is data on train work in t·km, speed and fuel consumption. The EEI assessment based on operating data will show how correctly the organization of vehicle operation is built, how non-stationary modes of the power plant and specific modes of traction influence the overall performance of the vehicle, how well the vehicle is selected for these operating conditions.

Analysis and Assessment of Tower Solar Collector Driven Trigeneration System

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Abdul Khaliq ◽  
Mathkar A. Alharthi ◽  
Saeed Alqaed ◽  
Esmail M. A. Mokheimer ◽  
Rajesh Kumar
Keyword(s):  
Energy Efficiency ◽  
Solar Collector ◽  
Lithium Bromide ◽  
Rankine Cycle ◽  
Significant Rise ◽  
Exergy Efficiency ◽  
Integrated System ◽  
Operating Conditions ◽  
Heating And Cooling ◽  
And Performance

Abstract This paper describes the development and performance assessment of a tower solar collector driven integrated system operating in trigeneration mode to generate electricity, heating, and cooling, in a carbon-free manner. The proposed system applies a heliostat-based central receiver unit as a base of solar energy input to drive the steam Rankine cycle which is combined with the process heater and the lithium bromide-water operated absorption chiller. An analysis is performed to monitor the behavior of energy and exergy efficiency at various operating conditions of the proposed trigeneration system. The computed results are authenticated with the reported literature. A comparison is made between the present findings and reported results in the form of exergy efficiency, total exergy destroyed, and energy efficiency. Consideration of process heat and cold along with electricity provides a promising increase in energy efficiency from 15.8% to 64.1% while the exergy efficiency is enhanced from 16.9% to 24.4%. Variation in direct normal irradiations from 600 W/m2 to 1000 W/m2 results in the significant rise of energetic and exergetic outcomes of the proposed trigeneration system. Out of 100% solar exergy supplied to the proposed trigeneration, 24% is generated as the exergetic output, 1.6% is lost to ambient, and the remaining 74.4% is the exergy destroyed in the system components.

Trust in Branded Autonomous Vehicles & Performance Expectations: A Theoretical Framework

2018 ◽  
Vol 62 (1) ◽  
pp. 1761-1765 ◽  
Author(s):  
Natalie Celmer ◽  
Russell Branaghan ◽  
Erin Chiou
Keyword(s):  
Systems Engineering ◽  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Theoretical Framework ◽  
Performance Expectations ◽  
Vehicle Performance ◽  
Vehicle Systems ◽  
Automated Technology ◽  
And Performance ◽  
Performance Perceptions

Future autonomous vehicle systems will be diverse in design and functionality because they will be produced by different brands. It is possible these brand differences yield different levels of trust in the automation, therefore different expectations for vehicle performance. Perceptions of system safety, trustworthiness, and performance are important because they help users determine how reliant they can be on the system. Based on a review of the literature, the system’s perceived intent, competence, method, and history could be differentiating factors. Importantly, these perceptions are based on both the automated technology and the brand’s personality. The following theoretical framework reflects a Human Systems Engineering approach to consider how brand differences impact perceived trustworthiness, performance expectations and ultimate safety of autonomous vehicles.

MODERN EQUIPMENT FOR DETERMINING TRACTOR-SPEED PROPERTIES OF THE VEHICLE: CHARACTERISTICS’ ANALYSIS IN LABORATORY CONDITIONS

2019 ◽  
Vol 16 (3) ◽  
pp. 276-289
Author(s):  
N. V. Savenkov ◽  
V. V. Ponyakin ◽  
S. A. Chekulaev ◽  
V. V. Butenko
Keyword(s):  
Environmental Performance ◽  
Operating Conditions ◽  
Special Role ◽  
Development Stages ◽  
Advantages And Disadvantages ◽  
Force Transfer ◽  
Characteristics Analysis ◽  
And Performance ◽  
Loading Devices ◽  
Structural Solutions

Introduction. At present, stands with running drums are widely used for various types of tests. Power stands play a special role. Such stands take the mechanical power from the driving wheels of the car. This simulates the process of movement of the vehicle under operating conditions. Such equipment has various designs, principles of operation and performance. It is also used in tests that are different by purpose, development stages and types: research, control, certification, etc. Therefore, it is necessary in order to determine the traction-speed, fuel-efficient and environmental performance characteristics.Materials and methods. The paper provides the overview of the power stands with running drums, which are widespread on the domestic market. The authors carried out the analysis of the main structural solutions: schemes of force transfer between the wheel and the drum; types of loading devices; transmission layout schemes and features of the control and measuring complex. The authors also considered corresponding advantages and disadvantages, recommended spheres of application, demonstrated parameters and characteristics of the units’ workflow, presented components and equipment.Discussion and conclusions. The authors critically evaluate existing models of stands with running drums. Such information is useful for choosing serial models of stands and for developing technical tasks for designing or upgrading the equipment.

Application of vacuum belt press filters for cane mud filtration and performance comparison with rotary filters

2014 ◽  
pp. 298-301 ◽  
Author(s):  
Arnaud Petit
Keyword(s):  
Electricity Consumption ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Vacuum Filter ◽  
Sugar Mill ◽  
Belt Press ◽  
Vacuum Belt ◽  
And Performance ◽  
Mud Filtration ◽  
The Impact

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.

Second-Law Analysis in a Steam Power Plant for Minimization of Avoidable Exergy Destruction

2010 ◽  
Author(s):  
Tapan K. Ray ◽  
Pankaj Ekbote ◽  
Ranjan Ganguly ◽  
Amitava Gupta
Keyword(s):  
Work Performance ◽  
Operating Conditions ◽  
Performance Criteria ◽  
Second Law ◽  
Feed Water ◽  
Exergy Destruction ◽  
Actual Performance ◽  
Time Operation ◽  
Major Equipment ◽  
Cycle Efficiency

Performance analysis of a 500 MWe steam turbine cycle is performed combining the thermodynamic first and second-law constraints to identify the potential avenues for significant enhancement in efficiency. The efficiency of certain plant components, e.g. condenser, feed water heaters etc., is not readily defined in the gamut of the first law, since their output do not involve any thermodynamic work. Performance criteria for such components are defined in a way which can easily be translated to the overall influence of the cycle input and output, and can be used to assess performances under different operating conditions. A performance calculation software has been developed that computes the energy and exergy flows using thermodynamic property values with the real time operation parameters at the terminal points of each system/equipment and evaluates the relevant rational performance parameters for them. Exergy-based analysis of the turbine cycle under different strategic conditions with different degrees of superheat and reheat sprays exhibit the extent of performance deterioration of the major equipment and its impact to the overall cycle efficiency. For example, during a unit operation with attemperation flow, a traditional energy analysis alone would wrongly indicate an improved thermal performance of HP heater 5, since the feed water temperature rise across it increases. However, the actual performance degradation is reflected as an exergy analysis indicates an increased exergy destruction within the HP heater 5 under reheat spray. These results corroborate to the deterioration of overall cycle efficiency and rightly assist operational optimization. The exergy-based analysis is found to offer a more direct tool for evaluating the commercial implication of the off-design operation of an individual component of a turbine cycle. The exergy destruction is also translated in terms of its environmental impact, since the irretrievable loss of useful work eventually leads to thermal pollution. The technique can be effectively used by practicing engineers in order to improve efficiency by reducing the avoidable exergy destruction, directly assisting the saving of energy resources and decreasing environmental pollution.

scholarly journals Integrated economic and environmental building classification and optimal seismic vulnerability/energy efficiency retrofitting

2021 ◽  
Author(s):  
Martina Caruso ◽  
Rui Pinho ◽  
Federica Bianchi ◽  
Francesco Cavalieri ◽  
Maria Teresa Lemmo
Keyword(s):  
Energy Efficiency ◽  
Life Cycle ◽  
Seismic Hazard ◽  
Environmental Impacts ◽  
Classification System ◽  
Seismic Vulnerability ◽  
Performance Metrics ◽  
Climatic Conditions ◽  
Economic Losses ◽  
Operational Energy

AbstractA life cycle framework for a new integrated classification system for buildings and the identification of renovation strategies that lead to an optimal balance between reduction of seismic vulnerability and increase of energy efficiency, considering both economic losses and environmental impacts, is discussed through a parametric application to an exemplificative case-study building. Such framework accounts for the economic and environmental contributions of initial construction, operational energy consumption, earthquake-induced damage repair activities, retrofitting interventions, and demolition. One-off and annual monetary expenses and environmental impacts through the building life cycle are suggested as meaningful performance metrics to develop an integrated classification system for buildings and to identify the optimal renovation strategy leading to a combined reduction of economic and environmental impacts, depending on the climatic conditions and the seismic hazard at the site of interest. The illustrative application of the framework to an existing school building is then carried out, investigating alternative retrofitting solutions, including either sole structural retrofitting options or sole energy refurbishments, as well as integrated strategies that target both objectives, with a view to demonstrate its practicality and to explore its ensuing results. The influence of seismic hazard and climatic conditions is quantitatively investigated, by assuming the building to be located into different geographic locations.

scholarly journals Importance-Performance Analysis of Health Perception among Korean Adolescents during the COVID-19 Pandemic

2021 ◽  
Vol 18 (3) ◽  
pp. 1280
Author(s):  
Seung-Man Lee ◽  
Wi-Young So ◽  
Hyun-Su Youn
Keyword(s):  
Mental Health ◽  
Physical Activity ◽  
Performance Analysis ◽  
Health Perception ◽  
Good Work ◽  
Online Questionnaire ◽  
Actual Performance ◽  
Korean Adolescents ◽  
Control Dimension ◽  
And Performance

This study assessed the health perceptions of 333 Korean adolescents during the coronavirus disease (COVID-19) pandemic via an online questionnaire administered in October 2020, which queried the perceived importance and actual performance of health behaviors. The health perception scales used in the survey consists of the six dimensions of mental health, disease, physical activity, sleep, diet, and sanitary health. The data were primarily analyzed using paired sample t-test for analysis of difference and importance-performance analysis (IPA). The IPA results were presented in four quadrants—“keep up the good work,” “concentrate here,” “low priority,” and “possible overkill.” The results indicated that first, there was a positive relationship between the importance and performance of all the subdimensions of health perception. Second, sanitary healthcare was rated as being of the greatest importance and was performed most, while physical activity management was rated least important and performed least. Third, statistically significant differences were found between importance and performance for all items of mental health, disease, physical activity, sleep, and diet dimensions, and some differences were found for items assessing the hygiene control dimension. Fourth, in the two-dimensional IPA model, “sanitary health” and “disease” are in Quadrant I (keep up the good work); “mental health,” in Quadrant II (concentrate here); and “physical activity,” “sleep,” and “diet,” in Quadrant III (low priority). No components of healthcare were in Quadrant IV (possible overkill). Based on these results, we emphasize the importance of adolescent health education and discuss solutions to enhance the performance of healthcare activities.

scholarly journals Power and Performance Evaluation of Memory-Intensive Applications

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4089
Author(s):  
Kaiqiang Zhang ◽  
Dongyang Ou ◽  
Congfeng Jiang ◽  
Yeliang Qiu ◽  
Longchuan Yan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Power Consumption ◽  
Job Scheduling ◽  
Memory System ◽  
Processor Core ◽  
Memory Efficiency ◽  
And Performance ◽  
Reasonable Use ◽  
Server System

In terms of power and energy consumption, DRAMs play a key role in a modern server system as well as processors. Although power-aware scheduling is based on the proportion of energy between DRAM and other components, when running memory-intensive applications, the energy consumption of the whole server system will be significantly affected by the non-energy proportion of DRAM. Furthermore, modern servers usually use NUMA architecture to replace the original SMP architecture to increase its memory bandwidth. It is of great significance to study the energy efficiency of these two different memory architectures. Therefore, in order to explore the power consumption characteristics of servers under memory-intensive workload, this paper evaluates the power consumption and performance of memory-intensive applications in different generations of real rack servers. Through analysis, we find that: (1) Workload intensity and concurrent execution threads affects server power consumption, but a fully utilized memory system may not necessarily bring good energy efficiency indicators. (2) Even if the memory system is not fully utilized, the memory capacity of each processor core has a significant impact on application performance and server power consumption. (3) When running memory-intensive applications, memory utilization is not always a good indicator of server power consumption. (4) The reasonable use of the NUMA architecture will improve the memory energy efficiency significantly. The experimental results show that reasonable use of NUMA architecture can improve memory efficiency by 16% compared with SMP architecture, while unreasonable use of NUMA architecture reduces memory efficiency by 13%. The findings we present in this paper provide useful insights and guidance for system designers and data center operators to help them in energy-efficiency-aware job scheduling and energy conservation.

scholarly journals Managing energy performance in buildings from design to operation using modelling and calibration

2021 ◽  
pp. 014362442110083
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Dejan Mumovic ◽  
Mike Davies
Keyword(s):  
Best Practice ◽  
Good Practice ◽  
Energy Performance ◽  
Operating Conditions ◽  
Design Stage ◽  
Performance Gap ◽  
Actual Performance ◽  
Simulation Tools ◽  
Calibration Protocol ◽  
Covering Design

To manage the concerns regarding the energy performance gap in buildings, a structured and longitudinal performance assessment of buildings, covering design through to operation, is necessary. Modelling can form an integral part of this process by ensuring that a good practice design stage modelling is followed by an ongoing evaluation of operational stage performance using a robust calibration protocol. In this paper, we demonstrate, via a case study of an office building, how a good practice design stage model can be fine-tuned for operational stage using a new framework that helps validate the causes for deviations of actual performance from design intents. This paper maps the modelling based process of tracking building performance from design to operation, identifying the various types of performance gaps. Further, during the operational stage, the framework provides a systematic way to separate the effect of (i) operating conditions that are driven by the building’s actual function and occupancy as compared with the design assumptions, and (ii) the effect of potential technical issues that cause underperformance. As the identification of issues is based on energy modelling, the process requires use of advanced and well-documented simulation tools. The paper concludes with providing an outline of the software platform requirements needed to generate robust design models and their calibration for operational performance assessments. Practical application The paper’s findings are a useful guide for building industry professionals to manage the performance gap with appropriate accuracy through a robust methodology in an easy to use workflow. The methodological framework to analyse building energy performance in-use links best practice design stage modelling guidance with a robust operational stage investigation. It helps designers, contractors, building managers and other stakeholders with an understanding of procedures to follow to undertake an effective measurement and verification exercise.

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