Identifying the early adopters of alternative fuel vehicles: A case study of Birmingham,United Kingdom

The transport sector has been identified as a significant contributor to greenhouse gas emissions. As part of its emissions reduction strategy, the United Kingdom Government is demonstrating support for new vehicle technologies, paying attention, in particular, to electric vehicles.Cluster analysis was applied to Census data in order to identify potential alternative fuel vehicle drivers in the city of Birmingham, United Kingdom. The clustering was undertaken based on characteristics of age, income, car ownership, home ownership, socio-economic status and education. Almost 60% of areas that most closely fitted the profile of an alternative fuel vehicle driver were found to be located across four wards furthest from Birmingham city centre, while the areas with the poorest fit were located towards the centre of Birmingham. The paper demonstrates how Census data can be used in the initial stages of identifying potential early adopters of alternative vehicle drivers. It also shows how such research can provide scope for infrastructure planning and policy development for local and national authorities, while also providing useful marketing information to car manufacturers.     

How does travel satisfaction sum up? An exploratory analysis in decomposing the door-to-door experience for multimodal trips

Transportation - Understanding how satisfaction with individual trip legs aggregates to the overall travel experience for different types of trips will enable the identification of the trip legs...     

用离子辐照的快恢复二极管等离子体技术为什么比发射效率降低的快恢复二极管等离子技术好

文章依据较高线电压的扩展比较了具有扩展安全工作区(SOA)的2个4.5 kV二极管.为了改善反向恢复特性,必须降低通态过程中靠近阳极的过剩载流子浓度.为了控制阳极的注入效率,比较了工艺技术的2种状态,即发射掺杂降低和在p掺杂区离子辐照.根据正向低电流密度(如2 A/cm2)恢复时50%的低开关损耗,表明局部寿命控制技术比发射掺杂降低技术更具优势.因此,通态特性一致的器件选择了这种改善.此外,观察到了离子辐照二极管的软开关性能.由校准的计算机仿真提供了用实验方法得到的这种性能的解释.     

铁路货车防盗系统设计

针对铁路运输的货物在途中被盗现象，提出了货车、集装箱防盗系统的设计原理，给出了系统硬件结构示意图和软件设计框图并对其在 Ｔ Ｍ Ｉ Ｓ中的使用前景进行了展望。     

Surface chlorophyll in the Black Sea over 1978–1986 derived from satellite and in situ data

Absolute values of chlorophyll a concentration and its spatial and seasonal variations in the Black Sea were assessed by using satellite CZCS and in situ data. Since the satellite CZCS had operated for the 1978–1986 period, CZCS data was used for assessing the past state of the Black Sea just before the onset of drastic changes observed in late 1980s. The approach used for the calculation of the absolute values of chlorophyll a concentration from CZCS data was based on the direct comparison of in situ chlorophyll a data and those of CZCS and by applying the algorithm developed for the transformation of CZCS data into chlorophyll a values. CZCS Level 2 data related with pigment concentration having a spatial resolution of 1 km at nadir were used. The daily Level 3 files were derived by binning Level 2 values into 4-km grid cells and the monthly and seasonal Level 3 files were created by averaging the daily Level 3 files over the corresponding period. In situ chlorophyll a data were obtained by spectrophotometric and fluorometric methods in 15 scientific cruises over the 1978–1986 period. Total number of ship-measured data used for the comparison with those CZCS values was 590.Chlorophyll a concentration (Chl) was derived from CZCS values (C) with regression equations Chl=kC; the coefficient of transformation k was calculated from six different data sets by taking into account distinctions between subregions and seasons. The reasons for difference in the k values have been analyzed.Statistical comparison of the chlorophyll a values measured in situ and those derived from CZCS data was based on log-transformed data and gave the following results: regression SLOPE=0.842, regression INTERCEPT=−0.081, coefficient of determination (R²)=0.806, root–mean–square ERROR=0.195. The mean monthly chlorophyll a distributions derived from CZCS data over 1978–1986 have been constructed and the mean seasonal chlorophyll a values in different regions have been calculated and analyzed. The significant difference in chlorophyll concentration between the western shelf regions and the open part of the Black Sea has been demonstrated, especially in warm season. At almost all seasons, the highest chlorophyll concentration is observed in the western interior shelf region which is under strong influence of Danube. The summer mean chlorophyll concentration in this region is 18 times higher than that in the open parts and about nine times higher than in the eastern shelf region. The greatest seasonal variations are observed in the open part of the Black Sea: chlorophyll concentration in cold season is four to six times higher than in summer and three to five times higher than in April and October. To the contrary, in the western interior shelf regions, the concentration is higher in May–October (about twice than that in November–March). Seasonal variations in the western outer shelf regions are smoothed out as compared with both the western interior shelf and the open regions.     

A summary of the formation and seasonal progression of the Northeast Water Polynya

A summary of the seasonal development of the Northeast Water Polynya ice cover characteristics is presented. This is based primarily on satellite remote sensing observations, with some in situ measurements, including both new and published data.     

钢结构空心截面连接杆件有效长度系数的初步研究

介绍了在钢桥连接系采用空心截面杆件时,连接系与主梁的连接问题中,偏心连接板有效长度系数的分析和确定.有效长度系数对于这种连接的设计起关键作用.在分析过程中,运用了NASTRAN有限元分析平台对实际问题进行了建模计算,并对结果进行了比较分析.从结果中,我们发现,连接板尺寸的变化可以得出不同的破坏荷载,从而推导出不同的有效长度系数.使用较长的连接板可以得出较小的有效长度系数.板厚的增大使有效长度系数明显增大.通过本文的几个模型分析结果,我们发现,有效长度系数取值在1.0～2.0之间.     

Examining the effects of out-of-home and in-home constraints on leisure activity participation in different seasons of the year

Using multi-day, multi-period travel diaries data of 56 days (four waves of two-week diaries) for 67 individuals in Stockholm, this study aims to examine the effects of out-of-home and in-home constraints (e.g. teleworking, studying at home, doing the laundry, cleaning and taking care of other household member[s]) on individuals’ day-to-day leisure activity participation decisions in four different seasons. This study also aims to explore the effects of various types of working schedules (fixed, shift, partial- and full-flexible) on individuals’ decisions to participate in day-to-day leisure activities. A pooled model (56 days) and wave-specific models (14 days in each wave) are estimated by using dynamic ordered Probit models. The effects of various types of working schedules are estimated by using 28 days of two waves’ data. The results show that an individual’s leisure activity participation decision is significantly influenced by out-of-home work durations but not influenced by in-home constraints, regardless of any seasons. Individuals with shift working hours engage less in day-to-day leisure activities than other workers’ types in both spring and summer seasons. The thermal indicator significantly affects individuals’ leisure activity participation decisions during the autumn season. Individuals exhibit routine behaviour characterized by repeated decisions in participating in day-to-day leisure activities that can last up to 14 days, regardless of any seasons.     

Dynamic analysis of seatbelt systems with anti-inertial release mechanisms

In order to prevent the uncontrolled release of seatbelt buckles due to high acceleration caused by pretensioners, anti-g buckles that have pendulum-shaped g-masses to block the releasing motion are commonly adopted in seatbelt systems. However, even with the wide applications of anti-g buckles, the underlying operational principles of anti-g buckles have yet to be investigated. This work studies conditions for the engagement of the g-mass to prevent inertial release, and conditions for maintaining a blocked state under very high acceleration. Using a multibody model of an anti-g buckle, the effects of various design parameters on the performance of the anti-g buckle have been examined. It turns out that design variables associated with the geometry of the g-mass and its contacting surface configuration play important roles. In order to account for the dynamic interaction between driver and seatbelt, a multibody model of a seatbelt system is combined with a dummy model to form a single dynamic system. Using the measured displacement of the buckle during the explosion of a pretensioner as the driving condition for simulation, dynamic analysis of the seatbelt with driver interaction has been carried out. Through comparison with measured and computed accelerations of webbing, which shows good agreement, the validity of the model has been demonstrated. The dynamic model for seatbelt and driver can be used as a design tool for the development of anti-g buckles.     

Dynamics analysis of an omni-directional vehicle

In a modern society, traffic congestion is a major problem in every metropolis. To solve the problem of traffic congestion an innovative omni-directional vehicle is proposed. This research has mainly focussed on developing the comprehensive vehicle dynamics model for an omni-directional road vehicle. Then the stability of the vehicle in the yaw plane was analysed under different scenarios based on the response of the side slip angle. Finally an active steering PID controller was suggested and which, according to the results of the simulation, improved the yaw plane stability.