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961.
In this feasibility study, we investigate the viability of using Liquefied Natural Gas (LNG) fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship’s safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship’s safety systems are required to comply with existing safety rules for this specific type of ship. 相似文献
962.
M. A. Hannan A. Hussain A. Mohamed S. A. Samad D. A. Wahab 《International Journal of Automotive Technology》2010,11(1):57-65
The need for an embedded system that can fuse incomplete, inconsistent, and imprecise decisions from several sensing systems
is a crucial step in achieving an effective decision for occupant safety measures. This paper deals with the decision fusion
strategies of a multi-sensing embedded system to achieve significant enhancement in the reliability of occupant safety through
the fused decisions. Multi-sensing approaches to determine weight, vision, and crash sensing are developed for occupant detection,
classification, position calculation, and crash detection. A rule-based decision fusion algorithm is then developed to fuse
the multi-sensing decisions. The developed sensing systems are incorporated into an embedded device. To execute the embedded
system, a system interface between the software and hardware is developed using Lab Window/CVI with the C programming language.
The experimental results demonstrated that the real time operation of the embedded system validate the effectiveness of the
decision fusion algorithm, characterize the safety measures and monitor the decision application. Several events were tested
that prove the performance of the embedded system is robust towards occupant safety measures. 相似文献
963.
Turbocharging port-injected Natural Gas (NG) engines allows them to recover gaseous-fuel related power gap with respect to
gasoline engines. However, turbolag reduction is necessary to achieve high performance during engine transient operations
and to improve vehicle fun-to-drive characteristics. Significant support for the study of turbocharged Compressed Natural
Gas (CNG) engines and guidelines for the turbo-matching process can be provided by 1-D numerical simulation tools. However,
1-D models are predictive only when a careful tuning procedure is set-up and carried out on the basis of the experimental
data. In this paper, a 1-D model of a Heavy-Duty (HD) turbocharged CNG engine was set up in the GT-POWER (Gamma Technologies
Inc., Westmont, IL, US) environment to simulate transient operations and to evaluate the turbolag. An extensive experimental
activity was carried out to provide experimental data for model tuning. The model buildup and tuning processes are described
in detail with specific reference to the turbocharger model, whose correct calibration is a key factor in accounting for the
effects of turbine flow pulsations. The second part of the paper focuses on the evaluation of different strategies for turbolag
reduction, namely, exhaust valve variable actuation and spark timing control. Such strategies were aimed at increasing the
engine exhaust-gas power transferred to the turbine, thus reducing the time required to accelerate the turbocharger group.
The effects of these strategies were examined for tip-in maneuvers at a fixed engine speed. Depending on the engine speed
and the applied turbolag reduction strategy, turbolag reductions from 70% to 10% were achieved. 相似文献
964.
G. Mirone 《International Journal of Automotive Technology》2010,11(4):461-469
The elastic response of a vehicle to an applied force determines the dynamic performance, comfort, and support of the vehicle,
where the elastic response depends primarily on the stiffness of the frame/chassis. Significant variations in the dynamic
response of a vehicle are typically achieved with suitable shock absorbing systems, which contribute significantly to whole
body flexibility. The defining feature of a go-kart is the lack of devices capable of absorbing shock and dampening vibration.
The tires and body of a go-kart, which consist of a frame of welded beams, must also function as a shock absorption system.
The objective of this study was to reproduce the elastic behavior of a commercially available Italian go-kart by modeling
the frame in a multibody ADAMS environment and to determine the effect of elastic features on the dynamic performance of the
vehicle. Frame stiffness was assessed by applying a static torsion moment, while the circular trajectory of the go-kart was
evaluated at different speeds and steering wheel angles. The proposed multibody, flexible model was validated by comparing
the static and dynamic response of the go-kart in simulated and experimental analyses. The results of numerical simulations
demonstrated that this method may be extended to the design of customized go-kart frames and to the tuning of go-karts for
specific racing conditions. 相似文献
965.
S. J. Lee 《International Journal of Automotive Technology》2010,11(4):471-479
The analytical model of an air spring can be effectively used for the design of air spring equipped vehicles to provide better
ride and handling characteristics along with various functions for passenger convenience. However, establishing a general
model of an air spring poses particular difficulties due to the severe nonlinearities in the stiffness and the hysteresis
effects, which are hardly observed in conventional coil springs. The purpose of this study is to develop a general analytic
model of an air spring — one which represents the main characteristics of stiffness and hysteresis and which can be connected
to a model of pneumatic systems desigined to control air spring height. To this end, the mathematical model was established
on the basis of thermodynamics with the assumptions that the thermodynamic parameters do not vary with the position inside
the air spring, that the air has the ideal gas property, and that the kinetic and potential energies of the air are negligible.
The analysis of the model has revealed that the stiffness is affected by the volume variation, the heat transfer, and the
variation of the air mass and the effective area. However, the hysteresis is mainly affected by the heat transfer and the
variation of the effective area. In particular, it was revealed that the increase of the volume due to the cross-sectional
area increases the stiffness, while the increase of the volume due to the other reason decreases it. In addition, the model
was used to develop the sufficient stability condition, and the stability of the model was analyzed. The paper also presents
the comparison between the simulation and experimental results to validate the established model and demonstrates the potential
of the model to be usefully employed for the development of the air spring and its algorithm for use in a pneumatic system. 相似文献
966.
T.P. Hutchinson R.W.G. Anderson 《Transportation Research Part D: Transport and Environment》2010,15(2):123-125
Attention is called to evidence that in collisions between vehicles of equal mass, and in single-vehicle collisions, there is unlikely to be a very strong effect of car size on injury severity, and that variation in crashworthiness within the set of car models of a given size has a much larger effect. Consequently, the secondary safety of a national fleet of small cars in the future could be as high as that of a national fleet of large cars today. 相似文献
967.
M.F. Yáñez S. Raveau J. de D. Ortúzar 《Transportation Research Part A: Policy and Practice》2010,44(9):744-753
Travel demand models typically use mainly objective modal attributes as explanatory variables. Nevertheless, it has been well known for many years that attitudes and perceptions also influence users’ behaviour. The use of hybrid discrete choice models constitutes a good alternative to incorporate the effect of subjective factors. We estimated hybrid models in a short-survey panel context for data among many alternatives. The paper analyses the results of applying these models to a real urban case study, and also proposes an approach to forecasting using these models. Our results show that hybrid models are clearly superior to even highly flexible traditional models that ignore the effect of subjective attitudes and perceptions. 相似文献
968.
J. Kim 《International Journal of Automotive Technology》2010,11(3):331-337
A methodology is presented for estimating vehicle handling dynamics, which are important to control system design and safety
measures. The methodology, which is based on an extended Kalman filter (EKF), makes it possible to estimate lateral vehicle
states and tire forces on the basis of the results obtained from sinusoidal steering stroke tests that are widely used in
the evaluation of vehicle and tire handling performances. This paper investigates the effect of vehicle-road system models
on the estimation of lateral vehicle dynamics in the EKF. Various vehicle-road system models are considered in this study:
vehicle models (2-DOF, 3-DOF, 4-DOF), tire models (linear, non-linear) and relaxation lengths. Handling tests are performed
with a vehicle equipped with sensors that are widely used by vehicle and tire manufacturers for handling maneuvers. The test
data are then used in the estimation of the EKF and identification of lateral tire model coefficients. The accuracy of the
identified values is validated by comparing the RMS error between experimentally measured states and regenerated states simulated
using the identified coefficients. The results show that the relaxation length of the tire model has a notable impact on the
estimation of lateral vehicle dynamics. 相似文献
969.
In this study, correlation between vehicle fuel efficiency and total fuel energy consumption is analyzed to support the energy consumption and greenhouse gas (GHG) emissions reduction master plan in Korea. The background and highlights of recently amended fuel economy regulations and fuel efficiency labeling standards in Korea are also introduced. 18 representative vehicle groups, classified by class, type, size, and fuel, are selected by investigating vehicle distribution statistics based on market penetration and registration data sets in order to reflect and predict total fuel energy consumption in the overall ground transportation sector in Korea. Validity of the vehicle survival patterns modeled and vehicle classification rules are confirmed by comparing national fuel energy consumption statistics to the total amount of fuel consumed by each selected representative vehicle group. The latter figures are approximated from representative number of registrations, weighted average fuel economy, and average annual distance traveled. 相似文献
970.
The marine shipping industry faces challenges to reduce engine exhaust emissions and greenhouse gases (GHGs) from ships, and in particular, carbon dioxide. International regulatory bodies such as the International Maritime Organization and National Environmental Agencies of many countries have issued rules and regulations to drastically reduce GHG and emissions emanating from marine sources. This study investigates the possibility of using natural gas and hydrogen as alternative fuels to diesel oil for marine gas turbines and uses a mathematical model to assess the effect of these alternative fuels on gas turbine thermodynamic performance. Results show that since natural gas is categorized as a hydrocarbon fuel, the thermodynamic performance of the gas turbine cycle using natural gas was close to that of the diesel case. However, the gas turbine thermal efficiency was found to be slightly lower for natural gas and hydrogen fuels compared to diesel fuel. 相似文献