912 resultados para Point-to-point speed enforcement
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National Highway Traffic Safety Administration, Washington, D.C.
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This thesis describes work completed on the application of H controller synthesis to the design of controllers for single axis high speed independent drive design examples. H controller synthesis was used in a single controller format and in a self-tuning regulator, a type of adaptive controller. Three types of industrial design examples were attempted using H controller synthesis, both in simulation and on a Drives Test Facility at Aston University. The results were benchmarked against a Proportional, Integral and Derivative (PID) with velocity feedforward controller (VFF), the industrial standard for this application. An analysis of the differences between a H and PID with VFF controller was completed. A direct-form H controller was determined for a limited class of weighting function and plants which shows the relationship between the weighting function, nominal plant and the controller parameters. The direct-form controller was utilised in two ways. Firstly it allowed the production of simple guidelines for the industrial design of H controllers. Secondly it was used as the controller modifier in a self-tuning regulator (STR). The STR had a controller modification time (including nominal model parameter estimation) of 8ms. A Set-Point Gain Scheduling (SPGS) controller was developed and applied to an industrial design example. The applicability of each control strategy, PID with VFF, H, SPGS and STR, was investigated and a set of general guidelines for their use was determined. All controllers developed were implemented using standard industrial equipment.
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Suihku/viira-nopeussuhde on perälaatikon huulisuihkun ja viiran välinen nopeusero. Se vaikuttaa suuresti paperin ja kartongin loppuominaisuuksiin, kuten formaatioon sekä kuituorientaatioon ja näin ollen paperin lujuusominaisuuksiin. Tämän johdosta on erityisen tärkeää tietää todellinen suihku/viira-nopeussuhde paperin- ja kartonginvalmistuksessa. Perinteinen suihku/viira-nopeussuhteen määritysmenetelmä perustuu perälaatikon kokonaispaineeseen. Tällä menetelmällä kuitenkin todellinen huulisuihkun nopeus saattaa usein jäädä tietämättä johtuen mahdollisesta virheellisestä painemittarin kalibroinnista sekä laskuyhtälön epätarkkuuksista. Tämän johdosta on kehitetty useita reaaliaikaisia huulisuihkun mittausmenetelmiä. Perälaatikon parametrien optimaaliset asetukset ovat mahdollista määrittää ja ylläpitää huulisuihkun nopeuden “on-line” määrityksellä. Perälaatikon parametrejä ovat mm. huulisuihku, huuliaukon korkeusprofiili, reunavirtaukset ja syöttövirtauksen tasaisuus. Huulisuihkun nopeuden on-line mittauksella paljastuu myös muita perälaatikon ongelmakohtia, kuten mekaaniset viat, joita on perinteisesti tutkittu aikaa vievillä paperin ja kartongin lopputuoteanalyyseillä.
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Recently, it has been shown that the speed of virus infections can be explained by time-delayed reactiondiffusion [J. Fort and V. Me´ndez, Phys. Rev. Lett. 89, 178101 (2002)], but no analytical solutions were found. Here we derive formulas for the front speed, valid in appropriate limits. We also integrate numerically the evolution equations of the system. There is good agreement with both numerical and experimental speeds
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The purpose of the study was to investigate the relative contribution of skate blade properties to on-ice skating speed. Thirty-two male ice hockey players (mean age = 19±2.65 yrs.) representing the Ontario Minor Hockey Association (OMHA; Midget AAA and Junior), Canadian Inter University Sport (CIS: Varsity), Ontario hockey league (OHL) and East Coast Hockey League (ECHL), and the playing positions of forwards (n=18) and defense (n=14) were recruited to participate. Skate related equipment worn by the players for the purpose of the research was documented and revealed that 80% of the players wore Bauer skates, Tuuk blade holders and LS2 skate blades. Subjects completed a battery of eight on-ice skating drills used to measure and compare two aspects of skating speed; acceleration [T1(s)] and total time to complete each drill [TT(s)] while skating on three skate blade conditions. The drills represented skills used in the game of hockey, both in isolation (e.g., forward skating, backward skating, stops and starts, and cornering) and in sequence to simulate the combination of skills used in a shift of game play. The three blade conditions consisted of (i) baseline, represented by the blades worn by the player throughout their current season of play; (ii) experimental blades (EB), represented by brand name experimental blades with manufacturers radius of contour and a standardized radius of hollow; and (iii) customized experimental blades (CEB), represented by the same brand name experimental blades sharpened to the players’ preference as identified in the baseline condition. No significant differences were found in acceleration time [T1(s)] or total time to complete [TT(s)] the isolated drills across blade conditions; however significant differences were revealed in both T1(s) and TT(s) measured during the execution of the sequenced drill across blade conditions. A iii Bonferroni post hoc test revealed that players skated significantly faster when skating on the CEB condition compared to the baseline condition (p≤.05). A questionnaire assessing subjects perceived comfort, confidence and effort expended while skating on the experimental blades revealed that players were significantly more comfortable when skating on the CEB versus the EB condition (p≤.05). Outcomes of the study provide evidence to suggest that the experimental skate blades customized with the players preferred blade sharpening characteristics results in faster skating speed in a combination drill representing skills performed in gameplay.
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Wider economic benefits resulting from extended geographical mobility is one argument for investments in high-speed rail. More specifically, the argument for high-speed trains in Sweden has been that they can help to further spatially extend labor market regions which in turn has a positive effect on growth and development. In this paper the aim is to cartographically visualize the potential size of the labor markets in areas that could be affected by possible future high-speed trains. The visualization is based on the forecasts of labor mobility with public transport made by the Swedish national mobility transport forecasting tool, SAMPERS, for two alternative high-speed rail scenarios. The analysis, not surprisingly, suggests that the largest impact of high-speed trains results in the area where the future high speed rail tracks are planned to be built. This expected effect on local labor market regions of high-speed trains could mean that possible regional economic development effects also are to be expected in this area. However, the results, in general, from the SAMPERS forecasts indicaterelatively small increases in local labor market potentials.
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Mode of access: Internet.
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National Highway Traffic Safety Administration, Washington, D.C.
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National Highway Traffic Safety Administration, Washington, D.C.
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National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.
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"Serial no. 97-70."
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Description based on: 2000.
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In Bohmian mechanics, a version of quantum mechanics that ascribes world lines to electrons, we can meaningfully ask about an electron's instantaneous speed relative to a given inertial frame. Interestingly, according to the relativistic version of Bohmian mechanics using the Dirac equation, a massive particle's speed is less than or equal to the speed of light, but not necessarily less. That is, there are situations in which the particle actually reaches the speed of light-a very nonclassical behavior. That leads us to the question of whether such situations can be arranged experimentally. We prove a theorem, Theorem 5, implying that for generic initial wave functions the probability that the particle ever reaches the speed of light, even if at only one point in time, is zero. We conclude that the answer to the question is no. Since a trajectory reaches the speed of light whenever the quantum probability current (psi) over bar gamma(mu)psi is a lightlike 4-vector, our analysis concerns the current vector field of a generic wave function and may thus be of interest also independently of Bohmian mechanics. The fact that the current is never spacelike has been used to argue against the possibility of faster-than-light tunneling through a barrier, a somewhat similar question. Theorem 5, as well as a more general version provided by Theorem 6, are also interesting in their own right. They concern a certain property of a function psi : R(4) -> C(4) that is crucial to the question of reaching the speed of light, namely being transverse to a certain submanifold of C(4) along a given compact subset of space-time. While it follows from the known transversality theorem of differential topology that this property is generic among smooth functions psi : R(4) -> C(4), Theorem 5 asserts that it is also generic among smooth solutions of the Dirac equation. (C) 2010 American Institute of Physics. [doi:10.1063/1.3520529]
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Public travel by motor vehicles is often necessary in road and street sections that have been officially closed for construction, repair, and/or other reasons. This authorization is permitted in order to provide access to homes and businesses located beyond the point of closure. The MUTCD does address appropriate use of specific regulatory signs at the entrance to closed sections; however, direct guidance for temporary traffic control measures within these areas is not included but may be needed. Interpretation and enforcement of common practices may vary among transportation agencies. For example, some law enforcement officers in Iowa have indicated a concern regarding enforcement and jurisdiction of traffic laws in these areas because the Code of Iowa only appears to address violations on roadways open to “public travel.” Enforcement of traffic laws in closed road sections is desirable to maintain safety for workers and for specifically authorized road users. In addition, occasional unauthorized entry by motor vehicles is experienced in closed road areas causing property damage. Citations beyond simple trespass may be advisable to provide better security for construction sites, reduce economic losses from damage to completed work, and create safer work zones.
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Previous to 1970, state and federal agencies held exclusive enforcement responsibilities over the violation of pollution control standards. However, recognizing that the government had neither the time nor resources to provide full enforcement, Congress created citizen suits. Citizen suits, first amended to the Clean Air Act in 1970, authorize citizens to act as private attorney generals and to sue polluters for violating the terms of their operating permits. Since that time, Congress has included citizen suits in 13 other federal statutes. The citizen suit phenomenon is sufficiently new that little is known about it. However, we do know that citizen suits have increased rapidly since the early 1980's. Between 1982 and 1986 the number of citizen suits jumped from 41 to 266. Obviously, they are becoming a widely used method of enforcing the environmental statutes. This paper will provide a detailed description, analysis and evaluation of citizen suits. It will begin with an introduction and will then move on to provide some historic and descriptive background on such issues as how citizen suit powers are delegated, what limitations are placed on the citizens, what parties are on each side of the suit, what citizens can enforce against, and the types of remedies available. The following section of the paper will provide an economic analysis of citizen suits. It will begin with a discussion of non-profit organizations, especially non-profit environmental organizations, detailing the economic factors which instigate their creation and activities. Three models will be developed to investigate the evolution and effects of citizen suits. The first model will provide an analysis of the demand for citizen suits from the point of view of a potential litigator showing how varying remedies, limitations and reimbursement procedures can effect both the level and types of activities undertaken. The second model shows how firm behavior could be expected to respond to citizen suits. Finally, a third model will look specifically at the issue of efficiency to determine whether the introduction of citizen enforcement leads to greater or lesser economic efficiency in pollution control. The database on which the analysis rests consists of 1205 cases compiled by the author. For the purposes of this project this list of citizen suit cases and their attributes were computerized and used to test a series of hypotheses derived from three original economic models. The database includes information regarding plaintiffs, defendants date notice and/or complaint was filed and statutes involved in the claim. The analysis focuses on six federal environmental statutes (Clean Water Act} Resource Conservation and Recovery Act, Comprehensive Environmental Response Compensation and Liability Act, Clean Air Act, Toxic Substances Control Act, and Safe Drinking Water Act) because the majority of citizen suits have occurred under these statutes.