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761.
Hydraulic hybrid powertrains are a critical technology used in buses to improve fuel economy and emission performance. New exploration in configuring a parallel hydraulic hybrid bus (PHHB) is developed in this paper with no changes made to the conventional base bus driveline. An integrated model and simulation of the parallel hydraulic hybrid bus is built based on AMESim, which is used to model the hydraulic powertrain and conventional bus driveline, and interlinked with a Matlab/Simulink/Stateflow model of the control unit. Compared to conventional buses, the fuel economy of the PHHB improved by 28% in real road tests at the SMVIC (National Center of Supervision and Inspection on Motor Products Quality (Shanghai)); the approximate improvement of fuel economy was 30% in simulated runs, which validates our model. Then a Non-linear Programming by Quadratic Lagrangian algorithm (NLPQL), is applied to optimize control strategies for improving fuel economy and emissions. Simulations also demonstrate that fuel economy and emission performance can be significantly improved. However, optimum parameters for maximum fuel economy and minimum emissions are not consistent. Simulation results show tradeoffs between fuel economy and emissions in PHHB, and optimal parameters can be selected by balancing design objectives. 相似文献
762.
S. H. Jeong C. G. Choi J. N. Oh P. J. Yoon B. S. Kim M. Kim K. H. Lee 《International Journal of Automotive Technology》2010,11(3):409-416
This paper presents a low cost design and implementation of a parallel parking assist system (PPAS) based on ultrasonic sensors.
Generally, a PPAS requires several types of sensors, such as an ultrasonic sensor, camera sensor, radar sensor and laser sensor
for parking space detection. However, our proposed PPAS only requires two ultrasonic sensors on the front and lateral sides
for parking space detection. Moreover, a steering angle sensor and wheel speed sensor installed in the vehicle are used to
obtain vehicle position information for localization in ultrasonic range data. The hardware architecture of the PPAS based
on an electronic control unit (ECU) module, sensor modules and a human machine interface (HMI) module was proposed. Moreover,
the software architecture of the PPAS is based on system initialization, scheduling, recognition and a control algorithm.
In particular, a novel sensor algorithm was proposed to minimize the vehicle corner error of the ultrasonic sensor. A prototype
of the PPAS based on the proposed architecture was constructed. The experimental results demonstrate that the implemented
prototype is robust and successfully performs parking space detection and automatic steering control. Finally, the low cost
design and implementation of the PPAS was possible due to the cheap ultrasonic sensors, simple hardware design and low computational
complexity of the proposed algorithm. 相似文献
763.
当私家车的使用可与公共交通结合时,人们会更倾向于乘坐公共交通出行. 因此,P+R(停车换乘系统)在为公共交通吸引客流的同时也为公共交通的运营起到重要的作用. 在建立和运营P+R系统时,制定合理的用户收费政策是诸多影响因素之一. 事实上,收费政策作为调节手段之一,利用其鼓励或约束停车场的各类用户,将有助于交通部门管理和经营P+R设施. 基于社会经济水平,本文为确定停车设施最优定价方案提供了一种新方法. 结合遗传算法,本文利用财务分析模型确定了P+R设施最优定价方案参数. 该模型应用于希腊雅典地铁网络的P+R设施. 结果表明,该模型可在短时间内提供近似最优定价方案. 另外,本文还在方便用户的计算机框架下结合该模型开发了相应决策支持系统. 相似文献
764.
Hai-Yan Lü 《西安交通大学学报(英文版)》2010,22(1):20-24
Objective To establish a flow-injection chemiluminescence method for the determination of doxorubicin, epirubicin and mitoxantrone and study its reaction mechanism. Methods In alkaline medium, chemiluminescence of luminol-potassium permanganate system could be inhibited obviously by anthracycline antibiotics. Combined with flow-injection technique, a new chemiluminescence method for determining the anthracycline antibiotics was set up. The chemiluminescence mechanism of the luminol-potassium permanganate system was also discussed. Results Under optimal conditions, the good linear ranges of doxorubicin, epirubicin and mitoxantrone were 5.0×10-9-1.0×10-6g/mL, 1.0×10-9-1.0×10-5g/mL and 3×10-9-1.0×10-6g/mL, respectively. The detection limits of doxorubicin, epirubicin and mitoxantrone were 3.0×10-9g/mL, 5.0×10-8g/mL and 2.0×10-9g/mL, respectively. During eleven repeated inter-day and intra-day precision tests of 1.0×10-6g/mL samples, the relative standard deviations corresponded to reference values of 3.0%, 2.8% and 2.1%. Conclusion The developed method is sensitive, accurate, rapid and of low cost. It can be applied to determine doxorubicin hydrochloride, epirubicin hydrochloride and mitoxantrone hydrochloride in injection preparations. 相似文献
765.
Objective To investigate the dynamic expression of the 20S proteasome in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic patients without vascular complications. Methods PBMCs were prepared from 30 type 2 diabetic patients and 30 nondiabetic controls. The general indexes including weight, height and blood pressure were recorded. Fasting plasma glucose, fasting plasma insulin and glycosylated hemoglobin were measured. The protein level of the 20S proteasome was measured by Western blotting. The mRNA expression levels of the 20S proteasome β1, β2 and β5 subunits were detected by real-time PCR. Results Compared with that in the nondiabetic controls, the protein level of the 20S proteasome was significantly increased in the diabetic patients and was positively associated with glycosylated hemoglobin. Conclusion Type 2 diabetic patients without vascular complications have an increased 20S proteasome expression, the significance of which needs to be explored by further study. 相似文献
766.
The nitrogen adsorption isotherms at 77.69 K were measured for two samples of activated carbon fibers and their microstructures were investigated. Among established isotherm equations, the Dubinin-Radushkevich equation showed the best agreement with the experimental data, while the Langmuir equation showed a large deviation when employed at low relative pressures. The MP method, t-method and αs-method were used to analyze the pore size distribution. The calculated average pore widths and BET (Brunauer-Emmett-Teller) surface areas for the sample A-13 were 0.86 nm and 1 286.60 m2/g, while for the sample A-16, they were 0.82 nm and 1 490.64 m2/g. The sample with larger pore width was more suitable to be used as additive in chemical heat pumps, while the other one could be used as adsorbent in adsorption refrigeration systems. 相似文献
767.
H. G. Jung Y. H. Lee H. J. Kang J. Kim 《International Journal of Automotive Technology》2009,10(2):219-228
This paper discusses the market trends and advantages of a safety system integrating LKS (Lane Keeping System) and ACC (Adaptive
Cruise Control), referred to as the LKS+ACC system, and proposes a method utilizing the range data from ACC for the sake of
lane detection. The overall structure of lane detection is the same as the conventional method using monocular vision: EDF
(Edge Distribution Function)-based initialization, sub-ROI (Region Of Interest) for left/right and distance-based layers,
steerable filter-based feature extraction, and model fitting in each sub-ROI. The proposed method adds only the system for
confining lane detection ROI to free space that is established by range data. Experimental results indicate that such a simple
adaptive ROI can overcome occlusion of lane markings and disturbance of neighboring vehicles. 相似文献
768.
769.
In order to plan bus operations, it is necessary for transit planners to understand what factors may influence travelers’ choice of buses for travels within a city. The proposed method involves various scenarios of a hypothetical bus operation which was rated by a group of individuals. Analysis of Covariance technique is employed to analyze people's sensitivities to their perceived levels of bus service characteristics. The technique involves:
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testing for the significant effects of varying levels of service characteristics upon people's intentions to use bus service, and
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assessing differences among various population segments in their sensitivity patterns towards bus service characteristics.
770.
Transportation - The maturing of autonomous driving technology in recent years has led to several pilot projects and the initial integration of autonomous pods and buses into the public transport... 相似文献