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651.
Abstract This article examines the efforts of the California Coastal Commission to pursue simultaneously goals of environmental quality and affordable housing in the same state‐imposed regulatory program. The authors conclude that the Commission made substantial progress toward realizing both ends. However, the coastal body fell victim to its own successes, and housing was removed from its jurisdiction. As the Coastal Commission exercised its authority, opposition grew in strength and numbers. Key opponents included local government, which lost land‐use regulatory power to the Commission, the building industry, whose relationships with coastal localities were disrupted, and local property owners, whose land was restricted to uses other than the most profitable one. 相似文献
652.
S. S. Merola P. Sementa C. Tornatore 《International Journal of Automotive Technology》2011,12(1):93-101
In this paper, flame front propagation during normal and abnormal combustion was investigated. Cycle-resolved flame emission
imaging was applied in the combustion chamber of a port fuel injection-boosted spark ignition engine. The engine was fueled
with a mixture of 90% iso-octane and 10% n-heptane by volume (Primary Reference Fuel 90: PRF90) and commercial gasoline. The
combustion process was monitored from the flame kernel formation until the exhaust valves opened. Different phenomena associated
with abnormal combustion were analyzed, including the fuel deposition burning. Moreover, the ignition surfaces and end-gas
auto-ignitions were investigated in terms of timing, location and frequency of occurrence. The analysis was performed by considering
different knocking intensities for both the selected fuels. 相似文献
653.
Due to decline in response rate to household travel surveys, it is essential that survey methods research explore the use of mixed-mode surveys. With this in mind, the Laboratoire d??économie des transports (Transport Economics Laboratory) conducted a web-based survey on non-respondents to a face-to-face household travel survey administered in the Lyon urban area in 2005?C2006. Comparative analysis of the figures shows that, overall, face-to-face respondents travel more than web-based respondents. This difference is partly explained by a high proportion of individuals who did not travel on the survey reference day and also by a lower trip level for those who travel. Classical regression methods can explain the individual mobility level with individuals socioeconomic characteristics, but do not take account of individuals who did not travel during the survey reference period. Using two econometric methods (simple Poisson and Hurdle Poisson regression) we examined factors affecting the decision to travel on one hand and the level of mobility on the other hand. This involves estimating the average daily mobility of individuals as a function of their socioeconomic characteristics while taking into account the fact that for a considerable part of the survey population, daily mobility is nil. Our approach intends firstly to define the causes of immobility better and secondly to characterise the mobility level with the help of a Hurdle model, so as to compare the results obtained in the web-based and faceto-face samples. 相似文献
654.
A. J. Torregrosa A. Broatch P. Olmeda C. Romero 《International Journal of Automotive Technology》2008,9(4):447-458
One of the major goals of engine designers is the reduction of fuel consumption and pollutant emissions while keeping or even
improving engine performance. In recent years, different technical issues have been investigated and incorporated into internal
combustion engines in order to fulfill these requirements. Most are related to the combustion process since it is responsible
for both fuel consumption and pollutant emissions. Additionally, the most critical operating points for an engine are both
the starting and the warming up periods (the time the engine takes to reach its nominal temperature, generally between 80°C
and 90°C), since at these points fuel consumption and pollutant emissions are larger than at any other points. Thus, reducing
the warm-up period can be crucial to fulfill new demands and regulations. This period depends strongly on the engine cooling
system and the different strategies used to control and regulate coolant flow and temperature. In the present work, the influences
of different engine cooling system configurations on the warm-up period of a Diesel engine are studied. The first part of
the work focuses on the modeling of a baseline engine cooling system and the tests performed to adjust and validate the model.
Once the model was validated, different modifications of the engine coolant system were simulated. From the modelled results,
the most favourable condition was selected in order to check on the test bench the reduction achieved in engine warm-up time
and to quantify the benefits obtained in terms of engine fuel consumption and pollutant emissions under the New European Driving
Cycle (NEDC). The results show that one of the selected configurations reduced the warm-up period by approximately 159 s when
compared with the baseline configuration. As a consequence, important reductions in fuel consumption and pollutant emissions
(HC and CO) were obtained.
On doctoral leave from Universidad Technológica de Pereira (Colombia) 相似文献
655.
The Prince Edward Islands pelagic ecosystem, south Indian Ocean: a review of achievements, 1976–1990
This review summarizes the main research findings of the multi-year oceanographic and biological studies conducted in the vicinity of the Prince Edward Archipelago during the period 1976 to 1990. The Prince Edward Islands represent a flow-through system on the mainstream of the Antarctic Circumpolar Current. Although there are no taxonomic differences between the pelagic communities of the upstream, inter-island and downstream regions, these mesoscale subsystems may operate differently. The mesoscale oceanographic and biological processes appear to be affected by the position of the Subantarctic Front (SAF) in the vicinity of the islands. Both the rich benthic community, which is supported by the local enhancement of primary production, and the strong advection of zooplankton/micronekton from the upstream region provide the food resources necessary for the survival of the huge community of land-based predators present on the islands. Collectively this is termed the ‘life-support system'. Future studies should concentrate on the meridional shifts in the position of the SAF and its influence on background productivity upstream and downstream of the Prince Edward Archipelago. 相似文献
656.
V. Gheorghita P. Gümpel A. Chiru J. Strittmatter 《International Journal of Automotive Technology》2014,15(3):469-474
The shape memory alloys present unusual thermo-mechanical properties. The most important of them are pseudo-elasticity and memory effect. The paper investigates this behaviour for the Ni-Ti wires under static (v < 50 mm/s) and dynamic conditions (v > 50 mm/s) at different temperatures. Ni-Ti actuator and pseudoelastic wires with diameter between 0.1 mm to 0.5 mm are being tested. For dynamic investigation a new testing plant able to satisfy the testing conditions is created. This new testing plant is still under development and the reported results originate from the first tests on this new machine. The new device is designed to reach speeds higher than 50 mm/s. These speeds can be achieved using a drop weight which will hit a bottom plate and by this the kinetic energy is transferred to the sample. Because the weight is dropped, the stroke for the sample is measured in two points. The force of this impact will be in-line measured and, if the sample will be electrically activated during this test, it is also possible to log the electrical voltage. To widen the application range of the shape memory alloys it is necessary to study their behaviour in the dynamic region. With the new testing facility, it is expected to test the damping properties of SMA wires. In that case, these results can generate the basis for finding new applications for shape memory alloys especially in the automotive safety industry. 相似文献
657.
W. Hong C. Choi W. Lee J. P. Hong D. Kum 《International Journal of Automotive Technology》2009,10(4):489-495
This paper proposes an advanced permanent magnet (PM) motor drive modeling for dynamic analysis of automotive control systems
with PM motor drives. To enhance the reusability of the proposed PM motor drive model, each component is modeled in an object-oriented
manner according to the physical partitioning of a real drive system, and userfriendly and well-organized interfaces are also
proposed. These characteristics enable this model to be used as a kind of a programming library. A multi-level modeling strategy
is also proposed, which helps make a compromise between model accuracy and simulation speed without structural modification
of the system model. The model and modeling strategy developed allow for a comprehensive analysis of each component and dynamic
analysis of the total system. System simulation results show the practical effectiveness of the proposed modeling strategy. 相似文献
658.
S. I. Kim G. H. Lee J. J. Lee J. P. Hong 《International Journal of Automotive Technology》2010,11(2):277-282
In this paper, a simple design method for improving the performance of an interior permanent magnet synchronous motor (IPMSM),
for driving the air-conditioning compressor used in hybrid electric vehicles, is presented. There are many design methods
that optimize the IPMSM. Each method deals with a variety of design factors, such as slot opening, pole arc, and rotor shape.
However, as the number of design variables increases, a lot of modeling and analysis time is needed in order to improve the
characteristics of an IPMSM. This paper demonstrates that the optimization of a double-layer IPMSM, satisfying the given design
conditions, is possible with only a flux barrier shape design. Then, response surface methodology is applied as the optimization
method, and the validity of the design approach is verified by comparison with test results. 相似文献
659.
A multilevel decentralized control scheme, the cascading technique, with application to the regulation of traffic on an urban freeway is presented. Performance of the decentralized system is compared to the performance of a centralized and a fixed time control structure. It is shown that the decentralized structure performs better than the centralized structure when incidents (lane closures) occur on the freeway. The freeway is modeled in terms of the aggregate variables section density and section speed, and is considered as a system of interconnected subsystems. 相似文献
660.
P.J.Th. Venhovens A.C.M. Van Der Knaap H.B. Pacejka 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(5):359-381
The paper discusses the attitude and vibration control of a passenger car on the basis of a full vehicle model. The analysis presented consists of two parts: (I) The introduction of a newly developed semi-active anti-roll/pitch system, (ii) An example of an actively suspended full vehicle model using a simple control strategy to improve ride comfort. The attitude control using semi-actively generated compensation forces prevents the car from rolling in curves and pitching during braking or accelerating. The strength of the system is the small energy consumption. The performance of the combination of both attitude and vibration control can compete with a fully active suspension system. 相似文献