Optimal Control of Four Wheel Steering Vehicle

This paper derives a method of controlling four wheel steering using optimal control theory. The purpose of control is to minimize the sideslip angle at the center of gravity. The control method feeds forward the steering wheel angle and feeds back the yaw velocity and the sideslip angle to the front and rear wheel angles. Theoretical studies show that the sideslip angle is reduced to zero even in the transient state, and that the understeer characteristic and frequency response can be changed regardless of the vehicle static margin. This Paper also examines various characteristics of the influence of the side force nonlinearities of tires and crosswinds.     

Liner alliances in the globalization era: a strategic tool for Asian container carriers

There has been an increased interest recently in alliances as successors of the large consortia that used to operate in the context of the conference system. Today, having become a common means and term of co-operation in a variety of other industries, alliances are posited as the response of the supply side of liner shipping to important changes on the demand side; alliances have, thus, become predominant in the most important routes for container cargoes. In recent years, however, the list of major container traffic generators and the list of major carriers of containerized cargoes have begun to contain more common entries, generally originating from the Asian region. Asia is, however, a large continent and the entrance of Asian carriers into liner shipping has not been simultaneous; the position, strategies and co-operation strategies of Asian companies have more differences than they share common features. Nevertheless, this paper suggests that alliances are a distinct form of co-operation in liner shipping and the empirical evidence based on a survey in the region supports this hypothesis. The similarity of attitudes of the major Asian container carriers vis a vis alliances is in this way revealing in terms of the range of motivations for participating in the alliance system in a globalized transport environment.     

Reducing pedestrian exposure to environmental pollutants: A combined noise exposure and air quality analysis approach

This study offers a combined analysis of pedestrian exposure to noise and air pollution within a specific urban setting in Dublin, Ireland. The impact of a recent boardwalk development on reducing pedestrian exposure to air and noise pollution is examined while modelling experiments are undertaken to explore the possibility of achieving further reductions in pollutant exposure through better urban design and planning. The results show that the boardwalk has reduced pedestrian exposure to air and noise pollution and that further reductions may be achieved by more strict segregation of pedestrian and road traffic in urban areas.     

Influence of injection parameters on the transition from PCCI combustion to diffusion combustion in a small-bore HSDI diesel engine

In this paper, the influence of injection parameters on the transition from Premixed Charge Combustion Ignition (PCCI) combustion to conventional diesel combustion was investigated in an optically accessible High-Speed Direct-Injection (HSDI) diesel engine using multiple injection strategies. The heat release characteristics were analyzed using incylinder pressure for different operating conditions. The whole cycle combustion process was visualized with a high-speed video camera by simultaneously capturing the natural flame luminosity from both the bottom of the optical piston and the side window, showing the three dimensional combustion structure within the combustion chamber. Eight operating conditions were selected to address the influences of injection pressure, injection timing, and fuel quantity of the first injection on the development of second injection combustion. For some cases with early first injection timing and a small fuel quantity, no liquid fuel is found when luminous flame points appear, which shows that premixed combustion occurs for these cases. However, with the increase of first injection fuel quantity and retardation of the first injection timing, the combustion mode transitions from PCCI combustion to diffusion flame combustion, with liquid fuel being injected into the hot flame. The observed combustion phenomena are mainly determined by the ambient temperature and pressure at the start of the second injection event. The start-of-injection ambient conditions are greatly influenced by the first injection timing, fuel quantity, and injection pressure. Small fuel quantity and early injection timing of the first injection event and high injection pressure are preferable for low sooting combustion.     

Chevrolet Volt on-road test programs in Canada part 1: Effects of drive cycle,ambient temperature and accessory usage on energy consumption and all-electric range

Environment Canada (EC) and Natural Resources Canada (NRCan) separately tested two 2012 Chevrolet Volts between 2013 and 2014 in Ottawa, Ontario on public roads in the summer and winter months using realistic cabin-climate control settings. More than 1300 trips were conducted over nine routes: three city, one congested, two arterial, one highway and two expressway routes. EC tests recorded cabin conditioning, traction battery and 12 V accessory power, select vehicle component temperatures, regulated emission rates and exhaust flow, and DC charge energy. Both NRCan and EC tests measured cumulative electrically driven distance (all-electric range), select CANbus signals and AC grid supply charge energy. Results from these studies were analysed to evaluate the overall performance of the Chevrolet Volt on public roads in climates representative of most of Canada (-27 °C to 37 °C) using realistic accessory settings. At 25 °C the Chevrolet Volt’s on-road all-electric EPA-method adjusted range is generally less than the U.S. EPA sticker rating (57.9 km). Cabin conditioning energy was found to be directly related to the difference between ambient and cabin temperature, except at low temperatures (< 0 °C) when the 1.4 L engine activates to assist the thermal management system. On average, heating the cabin in the winter months consumed significantly more electric energy than cooling the cabin in the summer months. Summer city and highway driving resulted in the lowest energy consumption (Wh/km), while congested and expressway driving cycles resulted in the highest. In the winter months, many differences between the drive cycles were not discernible due to the high cabin conditioning energy consumptions.     

揭露“法轮功”的唯心主义本质

清除“法轮功”的危害和影响，要认真分析包括其组织产生和泛滥的根源。不断解放和发展生产力，采取各种政策和措施，弘扬科学精神，反对愚昧落后。     

Phytoplankton dynamics related to water mass properties in the Gulf of Gabes: Ecological implications

The spatial distribution of chlorophylls and carotenoids was recorded throughout the Gulf of Gabes (South Ionian Sea) in March 2007, and was related to patterns of the physical structure and the nutrient concentrations.Two distinct water masses were identified based on the temperature and salinity (T–S) analysis: a cool and less salty Modified Atlantic Water (MAW) and a saltier Mediterranean Mixed Water (MMW). There was no significant difference in the mean nitrogen and phosphate concentrations between MMW and MAW, although the silica values were significantly higher in MAW. The Integrated chlorophyll a mean value was about 4 mg m^? 2, with a maximum of 13 mg m^? 2 at MAW stations.Higher Chlorophyll a records in typical MAW stations were mainly due to chlorophytes, which contributed up to 58% of the pigments concentrations in the MAW and about 46% in the MMW. The contribution of chlorophytes to total Chlorophyll a was found to be relatively stable throughout the water column. The contribution of diatoms, which were twofold higher in the MMW than in the MAW, did not exceed 17% of chlorophyll a and was mainly due to subsurface maxima. The chlorophytes, pelagophytes, prymnesiophytes and cryptophytes all together accounted for more than 77% of total chlorophyll a in the MAW and about 67% in the MMW.There were statistically significant differences between MMW and MAW in the pigment contribution of cyanobacteria and pelagophytes. These two taxa accounted for 13% and 24% of chlorophyll a respectively in the MAW and MMW indicating that these differences concerned phytoplankton classes at relatively low contributions to total chlorophyll a.     

Hydro-pneumatic Slow-active Suspension with Preview Control

In this work, the preview control problem is considered for fully active and hydro-pneumatic slow-active systems. Based on the quarter car model, linear optimal control theory is used to derive the control laws. The Pade approximation technique is used to represent the preview time resulting from a preview sensor mounted at the front bumper to measure the road irregularities ahead of the front wheels. The results for the slow-active system with preview showed that there is 15% improvement in ride comfort compared to slow-active without preview and 28.5% improvement over passive system at similar root mean square (r.m.s) dynamic tyre load and suspension working space. The performance gains are, however, lower by about 15% than those obtainable with the theoretically ideal, fully active system with preview. The power results for slow active with and without preview showed that a 2kW fixed displacement hydraulic pump is enough for full vehicle requirements.     

自发高血压大鼠心脏功能及血压的增龄性变化

４～１８周之雄性自发高血压大鼠（ＳＨＲ）与正常血压（ＷＫＹ）鼠各分为５个年龄组。乙醚麻醉下测取有关心功能指标，并以短暂的主动脉阻闭所得到的左室发展压峰值（ｐＤｅｖＰ，由左室收缩压减去左室舒张末压获得）作为左室最大压力产生能力的指标。实验结果显示：①各年龄组ＳＨＲ之动脉收缩压、舒张压、平均动脉压、左室收缩压均高于同龄组ＷＫＹ鼠（Ｐ＜０．０５）。ＳＨＲ之上述指标随年龄增长而增高。②各年龄组ＳＨＲ之ｐＤｅｖＰ均高于同龄组ＷＫＹ鼠（Ｐ＜０．０５）。ＳＨＲ之ｐＤｅｖＰ随年龄增长而增大。     

Biological effects of Mississippi River nitrogen on the northern gulf of Mexico—a review and synthesis

The Mississippi River currently delivers approximately 1.82 Tg N year⁻¹ (1.3×10¹¹ mol N year⁻¹) to the northern Gulf of Mexico. This large input dominates the biological processes of the region. The “new” nitrogen from the river stimulates high levels of phytoplankton production which in turn support high rates of bacterial production, protozoan and metazoan grazing, and fisheries production. A portion of the particulate organic matter produced in the pelagic food web sinks out of the euphotic zone where it contributes to high rates of oxygen consumption in the bottom waters of the inner shelf, resulting in the development of an extensive zone of hypoxia each summer. In spite of the significance of this river system to the coastal ocean of the northern gulf, we do not have an adequate understanding of the inputs, processing and ultimate fates of river nitrogen. Here we review available literature on this important system and propose a conceptual model showing how biological processes evolve in the river plume between the point of discharge and the point where plume waters are fully diluted by mixing with oceanic water.