山地城市建成环境对居民小汽车拥有影响研究——以贵阳市为例

为分析山地城市建成环境对居民小汽车拥有的影响，探究不同坡度下居民地形感知对小汽车拥有影响的差异，采用贵阳市中心城区不同坡度下的小区居民调研数据，引入3个观测变量来评价居民的地形感知，将结构方程模型（SEM）计算出的潜变量适配值融入Logit模型中，构建包含潜变量和显变量的SEM-Logit模型来研究主客观建成环境与小汽车拥有的关系。结果表明:坡度对小汽车拥有产生积极影响，但不同坡度下的地形感知对小汽车拥有的影响有所不同。在地形条件相对较好的环境中，当小区坡度小于8%，居民对地形感知并不强烈，并认为从小区步行到公共交通站点的距离和时间花费在其承受范围内。因此，地形感知并未对小汽车拥有造成显著影响；在小区坡度为8%~15%时，地形感知对小汽车拥有产生显著负效应。生活在该小区类型的居民，尤其是收入相对偏低的居民，更喜欢选择电动自行车出行，削弱了小汽车拥有量；当小区坡度大于15%时，小区坡度与小汽车拥有量具有正相关性。该小区类型的道路坡度大，居民出行过程中通常会经历频繁的上下坡，造成出行时间花费长，继而形成强烈的地形感知。这严重降低了居民出行选择步行或骑行的可能性，转而提升了小汽车拥有的概率。同时，在SEM-Logit模型中也证明了除地形因素外，家庭年收入、到地铁站最近距离、土地利用混合度、目的地可达性、出行态度对小汽车拥有具有较大影响。      

The high-expansion-ratio gasoline engine for the hybrid passenger car

A 50% reduction in CO₂ and fuel consumption has been achieved by the Toyota Hybrid System, which has been in mass production since 1997. This is achieved by the combination of two permanent magnet motors and a newly developed gasoline engine that is optimized in terms of its displacement and heat cycle. Delaying the closing timing of the intake valves effectively separates the compression ratio and expansion ratio, so that the expansion ratio, which is normally set from 9 : 1 to 10 : 1 to suppress knocking, can be set to 13.5 : 1. This new engine shows better than 230 g/kWh BSFC over a wide operating range. Motor-assisted quick start, improved catalyst warm-up, and the elimination of light-load firing allow the system to achieve very clean emissions levels.     

Development of a time-to-digital converter IC for laser radar

A CMOS time-to-digital converter IC with half-nanosecond resolution by inverter-delay-time has been developed for measuring time intervals with a fully digital circuit. A new circuit “ring-gate-delay” system using two revolution counters can make the area of the circuit far smaller than it would be without them. Accuracy is assured through digital processing with a 2 MHz crystal clock reference. A time resolution of 0.5 ns and a measurement range of 0–2200 ns using 1.5 μm CMOS were confirmed.     

A study on speed control law for automated driving of heavy-duty vehicles considering acceleration characteristics (simulation of transient responses)

In order to develop a proper speed control technique for automated driving of heavy-duty vehicles, in the situation of mixed traffic of heavy-duty vehicles and passengers cars, a simulation study is carried out considering the transient characteristics of heavy-duty vehicles in acceleration and deceleration. The control performance is observed and some problems to be solved are listed as follows: (1) to check control performance for time-dependent target speed and distance (2) to improve the control algorithms to suppress chattering of the acceleration.     

Road characteristics and environment factors associated with motorcycle fatal crashes in Malaysia

This study aims to determine risk factors contributing to traffic crashes in 9,176 fatal cases involving motorcycle in Malaysia between 2010 and 2012. For this purpose, both multinomial and mixed models of motorcycle fatal crash outcome based on the number of vehicle involved are estimated. The corresponding model predicts the probability of three fatal crash outcomes: motorcycle single-vehicle fatal crash, motorcycle fatal crash involving another vehicle and motorcycle fatal crash involving two or more vehicles. Several road characteristic and environmental factors are considered including type of road in the hierarchy, location, road geometry, posted speed limit, road marking type, lighting, time of day and weather conditions during the fatal crash. The estimation results suggest that curve road sections, no road marking, smooth, rut and corrugation of road surface and wee hours, i.e. between 00.00 am to 6 am, increase the probability of motorcycle single-vehicle fatal crashes. As for the motorcycle fatal crashes involving multiple vehicles, factors such as expressway, primary and secondary roads, speed limit more than 70 km/h, roads with non-permissible marking, i.e. double lane line and daylight condition are found to cause an increase the probability of their occurrence. The estimation results also suggest that time of day (between 7 pm to 12 pm) has an increasing impact on the probability of motorcycle single-vehicle fatal crashes and motorcycle fatal crashes involving two or more vehicles. Whilst the multinomial logit model was found as more parsimonious, the mixed logit model is likely to capture the unobserved heterogeneity in fatal motorcycle crashes based on the number of vehicles involved due to the underreporting data with two random effect parameters including 70 km/h speed limit and double lane line road marking.     

780 N/mm2 grade hot-rolled high-strength steel sheet for automotive suspension system

590 N/mm²-grade high-strength hot-rolled steel sheet has been applied to an automotive suspension system, and 780 N/mm²-grade has recently been applied on trial to the same parts. Both of the steels used for the suspension system are required to have good formability, especially high stretch-flangeability. This paper describes the effect of the microstructure of the steel on stretch-flangeability. The results of mill trials have shown that the bainitic-ferrite mono-phase microstructure has the best mechanical properties.     

Gasification and dry distillation of automobile shredder residue (ASR)

A variety of energy recovery technologies are being developed for recovering usable materials from automobile shredder residue (ASR), considering combustible gases and protecting the environment. We measured the pyrolysis characteristics of ASR in a gasification, dry distillation process. For efficiently recovering thermal energy, we determined that a heating value of the evolved gas of about 15.5 MJ/kg (3700 kcal/kg) can be achieved at a pyrolysis temperature greater than 500°C. We also determined that pyrolysis temperatures must be maintained below 700°C to prevent forming significant levels of oxidized copper in the ASR residue. In this paper we describe such a dry distillation system and operating conditions to achieve efficient operation.     

Development of the ultra-low-fuel-consumption hybrid car – INSIGHT

This paper describes the key technologies that achieve high fuel efficiency in a variety of driving conditions. For the global environment preservation, a vehicle has been developed with the objective of reducing fuel consumption and exhaust CO₂ to half that of Honda's typical low-fuel-consumption car Civic. These new technologies have been developed around a new hybrid power train layout. They include improvement in engine thermal efficiency, vehicle weight reduction and reduction of aerodynamic drag, resulting in extremely high fuel economy of 35 km/l at 10–15 mode. Also, the exhaust emissions are as low as half of the 2000 Japanese exhaust emission regulation. Consideration was also given to recycling compatibility, crash safety performance, comfortable running and styling to create a highly sophisticated ultra-low-fuel-consumption hybrid car.     

Combustion characteristics of a direct-injection stratified charge S.I. engine

A direct-injection stratified charge gasoline engine has been developed that can run on an air–fuel ratio of 40–50 : 1. Major characteristics of the engine system include swirl gas flow and fuel injection in a swirl spray at a maximum fuel pressure of 10 MPa. Another notable feature is that the intake port configuration is virtually identical to that of a conventional engine, allowing flexibility for shared use of components among different engines. This new engine achieves better fuel economy, lower cold-start HC emissions and higher power output than conventional multipoint injection engines.     

The new 1.3-liter 2-plug engine for the 2002 Honda Fit

A new 1.3 l engine developed for the 2002 model Honda “Fit” achieves high fuel economy (23 km/l in the Japanese 10.15 mode) and more than 50% emissions reduction from the 2000 standards in Japan. This engine has dual spark plugs that are located in a diagonal position in order to conduct the flame closely, and which control the ignition sequentially to burn rapidly. In addition, new technology of shot peening with MoS₂ reduced mechanical friction and a six-hole injector and oblique structuring converter reduced its emissions.     

Speed ratio control of a parallel layout double cavity half-toroidal CVT for four-wheel drive

A double cavity half-toroidal CVT has two variators, which gives a hint of a new four-wheel drive without a center differential gear unit by applying each of them to drive front and rear drive shafts independently. Torque re-circulation at cornering or different tire radii between front and rear tire is avoided by compensating the speed ratio of variator. The controller adjusts the attitude angle of power roller of the front variator against the rear by measuring the steering angle at cornering. This paper describes the speed ratio control system of the 4WD-CVT with speed ratio range of 1 : 8.7 and test results of vehicle motion mounted on a 3.2L RV.     

Do driver training programs reduce crashes and traffic violations? — A critical examination of the literature

This paper reviews the evaluation literature on the effectiveness of classroom and behind-the-wheel driver training. The primary focus is on North America programs as originally taught in high schools but now also by private instructors. Studies from the United Kingdom, Australia, New Zealand and Scandinavia are also included.By far the most rigorous study to date was the experimental study in DeKalb, Georgia, U.S.A. This study used a randomized design including a control group and a very large sample size to provide reasonable statistical precision. I reexamine the DeKalb data in detail and conclude that the study did show evidence of small short-term crash and violation reductions per licensed driver. However, when the accelerated licensure caused by the training is allowed to influence the crash and violation counts, there is evidence of a net increase in crashes.The other studies reviewed present a mixed picture but the better designed quasi-experimental evaluations usually showed no effects on crash rates but almost all suffer from inadequate sample size. I show that as many as 35,000 drivers would be required in a two group design to reliably detect a 10% reduction in crash rates.The advent of GDL laws in North America and other countries has largely remedied the concern over accelerated licensure of high risk teenage drivers by delaying the progress to full licensure. Conventional driver training programs in the U.S. (30 h classroom and 6 h on-the-road) probably reduce per licensed driver crash rates by as little as 5% over the first 6–12 months of driving. The possibility of an effect closer to 0 cannot be dismissed.Some GDLs contain an incentive for applicants to complete an advanced driver training program in return for shortening the provisional period of the GDL. The results of Canadian studies indicate that any effects of the driver training component are not sufficient to offset the increase in accidents due to increased exposure.There is no evidence or reason to believe that merely lengthening the number of hours on the road will increase effectiveness. Programs directed toward attitude change and risk taking better address the underlying cause of the elevated crash risk of young drivers but these behaviors are notoriously resistant to modification in young people.     

环形交叉口优化设计的思考和分析

交叉口是城市道路的重要组成部分，城市路网体系的咽喉和城市交通大动脉畅通的关键节点，故交叉口的选型至关重要。由于我国早期城市规划理念落后、城市发展不均衡、居民汽车拥有量逐步攀升及交叉口选型不合理等因素，交通拥堵已成为各城市日益突出的民生问题。以丰城市龙光大道人民医院环形交叉口优化方案为例，以问题为导向，形成多方案比选，最后选择合理的交叉口改造方式，以解决城市的交通安全和交通拥堵问题。     

Effects of field of view on lateral control performance in a vision-based autonomous vehicle

This paper addresses the effects of field of view on lateral control performance in a vision-based autonomous vehicle with simulation studies. When a vehicle drives around a circle with the lateral control algorithm proposed here, the performance is evaluated for a tracking error and ride quality for locations and sizes of the field of view. The results show that a field of view covering from 10 to 30 m in front of a vehicle is the optimal with respect to both the error and the ride quality, and it is independent of the vehicle speed.     

Knocking detection using wavelet instantaneous correlation method

In this study, we propose a new method for knocking detection that utilizes the vibration signal measured by a knock sensor under the knocking conditions known as a real mother wavelet (RMW), and carry out instantaneous correlation from the wavelet transform. We call this method the wavelet instantaneous correlation (WIC) method. The degree of similarity between the RMW and the vibration of the engine block was judged and only the knocking signal from the vibration of the engine block was extracted. The results obtained here show that the method proposed in this study is useful for knocking detection even if the engine speed is very high at 6000 rpm.     

Is vehicle ownership in urban india influenced by the availability of high quality dedicated public transit systems?

As India's economy grows, so too does the number of people who can afford to own vehicles. A downside of this rapid increase in private vehicle ownership is a corresponding increase in traffic congestion, air pollution, and carbon emissions. Although affordability may be one reason for the shift toward commuting via private vehicles, another contributing factor could be the quality of public transportation. The objective of this paper is to determine whether private vehicle ownership in large urban areas in India is influenced by the presence of high quality dedicated public transit systems. Consumer expenditure survey data acquired from the National Sample Survey Office (NSSO) for the year 2009–2010 were used to develop a vehicle ownership model for 26 Indian cities with a population of at least one million. The results show that the availability of public transportation has a negative correlation to motorcycle/moped ownership but has no strong effect on car ownership. These results should encourage governments in developing economies to invest in high-quality dedicated public transit systems.     

小汽车限行政策实践评述与反思

为解决小汽车保有量增加过快引发的交通相关问题,国内外许多城市开始实施限行政策.本文梳理总结了国内外城市限行政策的演化进程,发现尽管限行政策对缓解交通拥堵和改善空气污染有一定的作用,但不同城市的限行措施和限行效果也各有差异,出行者的一些规避限行的行为可能会对限行政策的实施效果产生一定的影响.     

Recycling technology of tire rubber

Material recycling technology for automotive tire rubber waste was developed by the continuous devulcanization method. The deodorization during the recycling process has become possible by the newly developed method. The devulcanized rubber obtained by these methods from tire rubber waste, generated from both the manufacturing products and scrap tires, shows excellent mechanical properties applicable to the new tire rubber compounds in engineering practice. Furthermore, it was confirmed by actual road tests that a test truck tire containing 10 wt % of the devulcanized rubber in the tread might exhibit tread wear behavior almost equal to that for the standard type with the new rubber compound.     

大型市政桥梁工程概算编制方法初探

由于中国经济和汽车拥有的迅速增长,目前全国各大中城市都在加快城市道路建设以提高城市交通通行能力,缓解城市交通拥堵状况。在这类建设中不乏大型复杂的桥梁工程。从广东省某市一座跨I级航道桥梁工程为例,介绍大型市政桥梁工程设计概算的编制方法及注意事项。