WorldWideScience

Sample records for acceleration lanes

  1. NVESD mine lane facility

    Habersat, James D.; Marshall, Christopher; Maksymonko, George

    2003-09-01

    The NVESD Mine Lane Facility has recently undergone an extensive renovation. It now consists of an indoor, dry lane portion, a greenhouse portion with moisture-controlled lanes, a control room, and two outdoor lanes. The indoor structure contains six mine lanes, each approximately 2.5m (width) × 1.2m (depth) × 33m(length). These lanes contain six different soil types: magnetite/sand, silt, crusher run gravel (bluestone gravel), bank run gravel (tan gravel), red clay, and white sand. An automated trolley system is used for mounting the various mine detection systems and sensors under test. Data acquisition and data logging is fully automated. The greenhouse structure was added to provide moisture controlled lanes for measuring the effect of moisture on sensor effectiveness. A gantry type crane was installed to permit remotely controlled positioning of a sensor package over any portion of the greenhouse lanes at elevations from ground level up to 5m without shadowing the target area. The roof of the greenhouse is motorized, and can be rolled back to allow full solar loading. A control room overlooking the lanes is complete with recording and monitoring devices and contains controls to operate the trolleys. A facility overview is presented and typical results from recent data collection exercises are presented.

  2. Lane Keeping Support

    Gayko, Jens

    Während längerer Fahrten auf autobahnähnlichen Straßen wird die Fahraufgabe des Spurhaltens von vielen Fahrern als lästig empfunden. Andererseits stellt das unbeabsichtigte Verlassen des Fahrstreifens eine häufge Unfallursache dar, wie bereits in Kapitel 34 beschrieben. Im Gegensatz zu der im vorigen Kapitel dargelegten Funktion des Lane Departure Warning (LDW) greift die hier beschriebene Spurhalteassistenz bzw. Lane Keeping Support (LKS) aktiv in das Lenksystem ein. Dadurch wird der Fahrer bei der Fahraufgabe des Spurhaltens unterstützt. Ziel dieser Funktion ist, je nach Auslegung, eine Erhöhung der Sicherheit, eine Erhöhung des Fahrkomforts oder eine Kombination beider Ziele. Ein wichtiges Merkmal der hier beschriebenen Systeme ist die Art der Assistenz, die über Warnungen hinausgeht, jedoch keine den Fahrer ersetzende Assistenz darstellt. Die motorische Ausführung der Lenkung des Fahrzeugs erfolgt somit durch den Fahrer und das LKS-System zugleich. Das Einsatzgebiet der heute verfügbaren Systeme erstreckt sich über autobahnähnliche Straßen in mittleren bis hohen Geschwindigkeiten und sichtbaren Markierungen der Fahrstreifen.

  3. Reference Model of Desired Yaw Angle for Automated Lane Changing Behavior of Vehicle

    Dianbo Ren; Guanzhe Zhang; Hangzhe Wu

    2016-01-01

    In this paper, it studies the problem of trajectory planning and tracking for lane changing behavior of vehicle in automatic highway systems. Based on the model of yaw angle acceleration with positive and negative trapezoid constraint, by analyzing the variation laws of yaw motion of vehicle during a lane changing maneuver, the reference model of desired yaw angle and yaw rate for lane changing is generated. According to the yaw angle model, the vertical and horizontal coordinates of trajectory for vehicle lane change are calculated. Assuming that the road curvature is a constant, the difference and associations between two scenarios are analyzed, the lane changing maneuvers occurred on curve road and straight road, respectively. On this basis, it deduces the calculation method of desired yaw angle for lane changing on circular road. Simulation result shows that, it is different from traditional lateral acceleration planning method with the trapezoid constraint, by applying the trapezoidal yaw acceleration reference model proposed in this paper, the resulting expected yaw angular acceleration is continuous, and the step tracking for steering angle is not needed to implement. Due to the desired yaw model is direct designed based on the variation laws of raw movement of vehicle during a lane changing maneuver, rather than indirectly calculated from the trajectory model for lane changing, the calculation steps are simplified.

  4. Shipping Lanes in U.S. Waters

    National Oceanic and Atmospheric Administration, Department of Commerce — The GIS REST service for "Shipping Lanes in U.S. waters" provides raster maps of the Shipping Lanes is a term used to indicate the general flow of merchant shipping...

  5. Lane-Changing Model in SUMO

    Erdmann, Jakob

    2014-01-01

    SUMO is an open source microscopic traffic simulation. A major component of modelling microscopic vehicle behavior is the lane-changing behavior on multi-lane roads. We describe a new model which uses a 4-layered hierarchy of motivations to determine the vehicle behavior during every simulation step and motivate in which ways it improves the current lane-changing model.

  6. Road Lane Detection by Discriminating Dashed and Solid Road Lanes Using a Visible Light Camera Sensor.

    Hoang, Toan Minh; Hong, Hyung Gil; Vokhidov, Husan; Park, Kang Ryoung

    2016-01-01

    With the increasing need for road lane detection used in lane departure warning systems and autonomous vehicles, many studies have been conducted to turn road lane detection into a virtual assistant to improve driving safety and reduce car accidents. Most of the previous research approaches detect the central line of a road lane and not the accurate left and right boundaries of the lane. In addition, they do not discriminate between dashed and solid lanes when detecting the road lanes. However, this discrimination is necessary for the safety of autonomous vehicles and the safety of vehicles driven by human drivers. To overcome these problems, we propose a method for road lane detection that distinguishes between dashed and solid lanes. Experimental results with the Caltech open database showed that our method outperforms conventional methods. PMID:27548176

  7. Measuring and Evaluation on Priority Lanes

    Shan Jiang

    2010-12-01

    Full Text Available Along with economic development, cities are increasingly congested in China. In order to eliminate peak-hour congestion, many cities establish priority lanes, commonly bus lanes. Although priority lanes could help Local Authorities gain its short-term management objectives, at the same time, it would greatly infringe on the legitimate rights of other vehicles and waste the scarce road resources, which is rigorously proved by mathematical models in this paper. In the long run, priority lanes would make social conflicts more intensified, and therefore highly undesirable. On the contrary, the social system engineering, combined with High Occupancy Vehicle (HOV lanes and High Occupancy Toll (HOT lanes, is the right way to alleviate overcrowding and build a Low-Carbon harmonious society.

  8. In What Situations Do High Occupancy Vehicle Lanes Perform Better Than General Purpose Lanes

    Dahlgren, Joy

    2001-01-01

    It is well known among HOV practitioners that the success of a high occupancy vehicle (HOV) lane in motivating people to shift to HOVs depends on maintaining a travel time differential between it and the adjacent general purpose lanes. This differential exists only if there is continuing delay on the general purpose lanes. The paradox inherent in this requirement – that HOV lanes as a congestion reduction measure require the continuance of congestion – is rarely noted. Because of this require...

  9. Vehicle Classification by Lane Allowance

    Vishakha Gaikwad

    2014-12-01

    Full Text Available Classification of vehicles from video is used for analysis of traffic, self-driving systems or security systems. This analysis is based on shape, size, velocity and track of vehicles. These features characterize vehicle in background subtraction and feature extraction methods. Extraction is done by active contours and morphological operations. Extracted vehicles are classified by applying various classification techniques. The combination of features and classification techniques varies with the application. Proposed system, Uses combination of K Nearest Neighbor (KNN and Decision Tree techniques to overcome constraints. These constraints are instances of an object, overlapping of objects, and scaling factor. KNN is utilized to classify vehicle by size and lane. Decision tree manipulates the combination of these two features to classify accurately which results increased performance. This system classifies objects into three classes. These classes are four wheeler, bikers and heavy duty vehicle extracted from video.

  10. Rebound Attack on the Full LANE Compression Function

    Matusiewicz, Krystian; Naya-Plasencia, Maria; Nikolic, Ivica; Sasaki, Yu; Martin Schlaeffer, Martin

    In this work, we apply the rebound attack to the AES based SHA-3 candidate Lane. The hash function Lane uses a permutation based compression function, consisting of a linear message expansion and 6 parallel lanes. In the rebound attack on Lane, we apply several new techniques to construct a...

  11. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  12. Dedicated lanes, tolls and ITS technology

    Lindsey, Robin

    2009-01-01

    The merits of separating cars and trucks have long been debated. Potential advantages include smoother traffic flows, lower accident rates, improved air quality and reduced maintenance and road infrastructure costs. Large trucks are often banned from urban roads and restricted to certain lanes on many highways but there are no dedicated truck facilities. However, truck-only lanes and truck tollways are now being actively studied. Tolls on cars and trucks are also becoming increasingly common ...

  13. Camera calibration from road lane markings

    Fung, GSK; Yung, NHC; Pang, GKH

    2003-01-01

    Three-dimensional computer vision techniques have been actively studied for the purpose of visual traffic surveillance. To determine the 3-D environment, camera calibration is a crucial step to resolve the relationship between the 3-D world coordinates and their corresponding image coordinates. A novel camera calibration using the geometry properties of road lane markings is proposed. A set of equations that computes the camera parameters from the image coordinates of the road lane markings a...

  14. The Walker Lane in northeastern California

    Saucedo, G.J.; Wagner, D.L.; Grose, T.L.T.

    1990-01-01

    The Walker Lane (Locke and others, 1940) was defined as a narrow northwest-trending dextral fault zone that separates basin- and range topography on the east from diverse topography on the west that extends discontinuously from Lake Mead to Honey Lake. The term Walker Lane Belt (Steward, 1988) expands the feature to include a wide zone east of the Sierra Nevada. Pease (1969), Hannah (1977), and Grose (1986) suggested that the tectonic characteristics of Walker Lane continue into the Modoc Plateau. The authors believe that it is useful to recognize the Walker Lane or Walker Lane Belt in the Modoc Plateau. Within the Modoc Plateau, a 25-km wide (15-mile wide) zone of northwest-southeast faults herein recognized as the Walker Lane, trends N35{degree}W from Honey Lake Basin to Medicine Lake Highland. Mapping in the Eagle Lake area revealed northwest-southeast, north-south, and northeast-southwest late Quaternary faults and rifts, eruptive fissures, small tectonic depressions, and the large Eagle Lake volcano-tectonic depression. To the east is a remarkably unfaulted Neogene volcanic terrane extending 70 km (42 miles) eastward to the Dry Valley-Smoke Creek Desert fault system in Nevada. To the west in the Cascades complex late Pliocene-Quaternary faulting, linear basaltic cones, and andesite volcanoes are all aligned N15{degree}-30{degree}W. This Modoc part of the Walker Lane Belt displays blocks tilted mostly 3{degree}-10{degree}E bounded by west-dipping normal faults and right diagonal normal faults. Left stepping north-south trending rifts occur within northwest trending, straight right diagonal-slip fault zones.

  15. Effects of Car Accidents on Three-Lane Traffic Flow

    Jianzhong Chen

    2014-01-01

    Full Text Available A three-lane traffic flow model is proposed to investigate the effect of car accidents on the traffic flow. The model is an extension of the full velocity difference (FVD model by taking into account the lane changing. The extended lane-changing rules are presented to model the lane-changing behaviour. The cases that the car accidents occupy the exterior or interior lane, the medium lane, and two lanes are studied by numerical simulations. The time-space diagrams and the current diagrams are presented, and the traffic jams are investigated. The results show that the car accident has a different effect on the traffic flow when it occupies different lanes. The car accidents have a more serious effect on the whole road when they occupy two lanes. The larger the density is, the greater the influence on the traffic flow becomes.

  16. A new traffic model with a lane-changing viscosity term

    Ko, Hung-Tang; Liu, Xiao-He; Guo, Ming-Min; Wu, Zheng

    2015-09-01

    In this paper, a new continuum traffic flow model is proposed, with a lane-changing source term in the continuity equation and a lane-changing viscosity term in the acceleration equation. Based on previous literature, the source term addresses the impact of speed difference and density difference between adjacent lanes, which provides better precision for free lane-changing simulation; the viscosity term turns lane-changing behavior to a “force” that may influence speed distribution. Using a flux-splitting scheme for the model discretization, two cases are investigated numerically. The case under a homogeneous initial condition shows that the numerical results by our model agree well with the analytical ones; the case with a small initial disturbance shows that our model can simulate the evolution of perturbation, including propagation, dissipation, cluster effect and stop-and-go phenomenon. Project supported by the National Natural Science Foundation of China (Grant Nos. 11002035 and 11372147) and Hui-Chun Chin and Tsung-Dao Lee Chinese Undergraduate Research Endowment (Grant No. CURE 14024).

  17. Continuum modelling of multi-lane heterogeneous traffic flow operations

    Hoogendoorn, S.P.; Bovy, P.H.L.

    1998-01-01

    This report represents the second report in regarding macroscopic traffic flow modelling. In this report we present a multiple lane generalisation of the aggregate-lane multiple user-class model. Key to its derivation is the lane-specific multiple user-class phase-space density (MUCPSD), generalisin

  18. Virtual queuing at airport security lanes

    Lange, de R.; Samoilovich, I.; Rhee, van der B.

    2013-01-01

    Airports continuously seek opportunities to reduce the security costs without negatively affecting passenger satisfaction. In this paper, we investigate the possibilities of implementing virtual queuing at airport security lanes, by offering some passengers a time window during which they can arrive

  19. Particle Swarm Optimization of Speed in Unplanned Lane Traffic

    Prasun Ghosal

    2012-08-01

    Full Text Available Analysis of Speed Optimization Technique in Traffic is a very promising research problem. Searching foran efficient optimization method to increase the degree of speed optimization and thereby increasing thetraffic flow in a lane is a widely concerning issue. However, there has been a limited research effort on theoptimization of the lane usage with speed optimization. This paper presents a novel technique to solve theproblem optimally using the knowledge base analysis of speeds of vehicles, population of lanes , usingpartial modification of Swarm Intelligence which, in turn will act as a guide for design of lanes optimally toprovide better optimized traffic with less number of transitions of vehicles between lanes..

  20. Development of lane change aid system; Lane change aid system no kaihatsu

    Uemura, H.; Yoshida, T.; Butsuen, T. [Mazda Motor Corp., Hiroshima (Japan); Sakai, N.; Nakano, T.; Nakamoto, T.

    1997-10-01

    We have developed a lane change aid system, which detects vehicles behind in adjacent lanes with CCD images, shows the driver the information of vehicle location with a head-up display, and warns him/her if necessary. By comparing the brightness on two CCD images, distance distribution along several CCD lines is measured. To assure the effective vehicle detection on public roads, we have developed a detection algorithm which distinguishes vehicles and guard-rails by observing the patterns of measured distances. We will show the system configuration, detection logic, and the system evaluation on public road. 5 refs., 12 figs.

  1. A Dust Lane in the Radio galaxy 3C270

    Mahabal, Ashish; Kembhavi, Ajit; Singh, K. P.; Bhat, P.N.; Prabhu, T. P.

    1995-01-01

    We present broad band surface photometry of the radio galaxy 3C270 (NGC~4261). We find a distinct dust lane in the $V-R$ image of the galaxy, and determine its orientation and size. We use the major axis profile of the galaxy to estimate the optical depth of the dust lane, and discuss the significance of the lane to the shape of the galaxy.

  2. Bus Lanes with Intermittent Priority: Screening Formulae and an Evaluation

    Eichler, Michael; Daganzo, Carlos F.

    2005-01-01

    This paper evaluates strategies for operating buses on signal-controlled arterials using special lanes that are made intermittently available to general traffic. The advantage of special bus lanes, intermittent or dedicated, is that they free buses from traffic interference; the disadvantage is that they disrupt traffic. We find that intermittent lanes, unlike dedicated ones, do not significantly reduce street capacity. Intermittence, however, increases the average traffic density at which th...

  3. Design and development of multi-lane smart electromechanical actuators

    Annaz, Fawaz Yahya

    2014-01-01

    Design and Development of Multi-Lane Smart Electromechanical Actuators presents the design of electromechanical actuators in two types of architectures, namely, Torque Summed Architecture (TSA) and Velocity Summed Architecture, (VSA). It examines them in: * Hardware redundancy, where the architecture is made up of 3 or 4 lanes. * Digital Math Model redundancy, where a more compact two lanes architectures will be presented. The book starts with the very basic concepts and introduces the design process logically so that an understanding of the smart multi-lane systems that drive an aileron

  4. Intelligent driving in traffic systems with partial lane discipline

    Assadi, Hamid; Emmerich, Heike

    2013-04-01

    It is a most common notion in traffic theory that driving in lanes and keeping lane changes to a minimum leads to smooth and laminar traffic flow, and hence to increased traffic capacity. On the other hand, there exist persistent vehicular traffic systems that are characterised by habitual disregarding of lane markings, and partial or complete loss of laminar traffic flow. Here, we explore the stability of such systems through a microscopic traffic flow model, where the degree of lane-discipline is taken as a variable, represented by the fraction of drivers that disregard lane markings completely. The results show that lane-free traffic may win over completely ordered traffic at high densities, and that partially ordered traffic leads to the poorest overall flow, while not considering the crash probability. Partial order in a lane-free system is similar to partial disorder in a lane-disciplined system in that both lead to decreased traffic capacity. This could explain the reason why standard enforcement methods, which rely on continuous increase of order, often fail to incur order to lane-free traffic systems. The results also provide an insight into the cooperative phenomena in open systems with self-driven particles.

  5. LANE MARKING DETECTION IN CLUTTERED ENVIRONMENT

    李青; 郑南宁; 程洪

    2003-01-01

    Objective To determine the positions of marking in the presence of distracting shadows, highlight, pavement cracks, etc. Methods RGB color space is transformed into I1I2I3 color space and I2 component was used to form a new image with less effect of the clutter. Using an improved edge detection operator, an edge strength map was produced, and binarilized by adaptive thresholds. The binary image was labeled and circularity of all connected components is calculated. The Self-Organizing Mapping is adopted to extract regions which imply potential marking. Finally the position of marking was obtained by curve fitting. Results Color information was utilized fully, all thresholds were set adaptively and lane marking could be detected in challenging images with shadows, highlight or other cars. Conclusion The method based on circularity of connected components shows its outstanding robustness to lane marking detection and has a wide variety of applications in the areas of vehicle autonomous navigation and driver assistance system.

  6. Lane detection using road planar information

    He, Qiang; Chu, Chee-Hung H.

    2011-06-01

    Intelligent vehicles have many applications in the military, aerospace, and other industries, including land-mine detection for the military, patient transportation in hospitals, and many other domains that often require automation to reduce risks to the human operators. One of important tasks of intelligent vehicles is the navigation, whose goal is to extract and determine the appropriate path that leads to a destination based on perceived environmental information. The objective of our work is to develop a simple and effective method to detect and extract road lanes and boundaries. We propose a solution by incorporating the planar information of road surfaces. We first detect all possible edges in the captured images. The straight lanes and boundaries are extracted as straight lines, which generate a vanishing point. The straight lines are described with Hough transform. A cluster analysis in Hough space is used to detect the vanishing point on road. Further, we search lines passing through the vanishing point from 180 degrees to 270 degrees and from 0 degree to negative 90 degrees. The first two strong lines will be extracted as road boundaries.

  7. An unusual ophthalmic finding in Lane-Hamilton syndrome.

    Villegas, Victor M; Rachitskaya, Aleksandra V; Lam, Byron L; McKeown, Craig A; Berrocal, Audina M

    2014-12-01

    Lane-Hamilton syndrome is a rare condition that is characterized by idiopathic pulmonary hemosiderosis and celiac disease. We report the case of an 18-month-old girl with Lane-Hamilton syndrome who had unilateral pigmentary retinopathy. PMID:25448145

  8. Lane-changing model with dynamic consideration of driver's propensity

    Wang, Xiaoyuan; Wang, Jianqiang; Zhang, Jinglei; Ban, Xuegang Jeff

    2015-07-01

    Lane-changing is the driver's selection result of the satisfaction degree in different lane driving conditions. There are many different factors influencing lane-changing behavior, such as diversity, randomicity and difficulty of measurement. So it is hard to accurately reflect the uncertainty of drivers' lane-changing behavior. As a result, the research of lane-changing models is behind that of car-following models. Driver's propensity is her/his emotion state or the corresponding preference of a decision or action toward the real objective traffic situations under the influence of various dynamic factors. It represents the psychological characteristics of the driver in the process of vehicle operation and movement. It is an important factor to influence lane-changing. In this paper, dynamic recognition of driver's propensity is considered during simulation based on its time-varying discipline and the analysis of the driver's psycho-physic characteristics. The Analytic Hierarchy Process (AHP) method is used to quantify the hierarchy of driver's dynamic lane-changing decision-making process, especially the influence of the propensity. The model is validated using real data. Test results show that the developed lane-changing model with the dynamic consideration of a driver's time-varying propensity and the AHP method are feasible and with improved accuracy.

  9. Particle Swarm Optimization of Speed in Unplanned Lane Traffic

    Prasun Ghosal

    2012-07-01

    Full Text Available Analysis of Speed Optimization Technique in Traffic is a very promising research problem. Searching for an efficient optimization method to increase the degree of speed optimization and thereby increasing the traffic flow in a lane is a widely concerning issue. However, there has been a limited research effort on the optimization of the lane usage with speed optimization. This paper presents a novel technique to solve the problem optimally using the knowledge base analysis of speeds of vehicles, population of lanes , using partial modification of Swarm Intelligence which, in turn will act as a guide for design of lanes optimally to provide better optimized traffic with less number of transitions of vehicles between lanes..

  10. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    Davis, L. C.

    2016-06-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested state at the bottleneck. The nature of the congested state, when it occurs, appears to be similar under a variety of conditions. Typically 80-100 vehicles are approximately equally distributed between the lanes in the 500 m region prior to the end of the terminated lane. Without the adaptive cruise control capability, connected vehicles can delay the onset of congestion but do not increase the asymptotic flow past the bottleneck. Calculations are done using the Kerner-Klenov three-phase theory, stochastic discrete-time model for manual vehicles. The dynamics of the connected vehicles is given by a conventional adaptive cruise control algorithm plus commanded deceleration. Because time in the model for manual vehicles is discrete (one-second intervals), it is assumed that the acceleration of any vehicle immediately in front of a connected vehicle is constant during the time interval, thereby preserving the computational simplicity and speed of a discrete-time model.

  11. Lane-changing behavior and its effect on energy dissipation using full velocity difference model

    Wang, Jian; Ding, Jian-Xun; Shi, Qin; Kühne, Reinhart D.

    2016-07-01

    In real urban traffic, roadways are usually multilane with lane-specific velocity limits. Most previous researches are derived from single-lane car-following theory which in the past years has been extensively investigated and applied. In this paper, we extend the continuous single-lane car-following model (full velocity difference model) to simulate the three-lane-changing behavior on an urban roadway which consists of three lanes. To meet incentive and security requirements, a comprehensive lane-changing rule set is constructed, taking safety distance and velocity difference into consideration and setting lane-specific speed restriction for each lane. We also investigate the effect of lane-changing behavior on distribution of cars, velocity, headway, fundamental diagram of traffic and energy dissipation. Simulation results have demonstrated asymmetric lane-changing “attraction” on changeable lane-specific speed-limited roadway, which leads to dramatically increasing energy dissipation.

  12. A Nested PID Steering Control for Lane Keeping in Vision Based Autonomous Vehicles

    Marino, R; SCALZI,S; Netto, M.

    2009-01-01

    In this paper a nested PID steering control for lane keeping in vision based autonomous vehicles is designed to perform path following in the case of roads with an uncertain curvature. The control input is the steering wheel angle: it is designed on the basis of the yaw rate, measured by a gyroscope, and the lateral offset, measured by the vision system as the distance between the road centerline and a virtual point at a fixed distance from the vehicle. No lateral acceleration and no lateral ...

  13. Shipping Fairways, Lanes, and Zones for US waters

    National Oceanic and Atmospheric Administration, Department of Commerce — Various shipping zones delineate activities and regulations for marine vessel traffic. Traffic lanes define specific traffic flow, while traffic separation zones...

  14. Social dilemma structures hidden behind traffic flow with lane changes

    Aiming to merge traffic flow analysis with evolutionary game theory, we investigated the question of whether such structures can be formed from frequent lane changes in usual traffic flow without any explicit bottlenecks. In our model system, two classes of driver-agents coexist: C-agents (cooperative strategy) always remain in the lane they are initially assigned, whereas D-agents (defective strategy) try to change lanes to move ahead. In relatively high-density flows, such as the metastable and high-density phases, we found structures that correspond to either n-person prisoner dilemma (n-PD) games or quasi-PD games. In these situations, lane changes by D-agents create heavy traffic jams that reduce social efficiency. (paper)

  15. Managing Rush Hour Congestion with Lane Reversal and Tradable Credits

    Qing Li

    2014-01-01

    Full Text Available Within the morning and evening rush hour, the two-way road flows are always unbalanced in opposite directions. In order to make full advantage of the existing lanes, the two-way road lane has to be reallocated to play the best role in managing congestion. On the other hand, an effective tradable credit scheme can help to reduce the traffic demand and improve fairness for all travelers. So as to alleviate the commute congestion in urban transportation network, a discrete bilevel programming model is established in this paper. In the bilevel model, the government at the upper level reallocates lanes on the two-way road to minimize the total system cost. The traveler at the lower level chooses the optimal route on the basis of both travel time and credit charging for the lanes involved. A numerical experiment is conducted to examine the efficiency of the proposed method.

  16. Microscopic modeling of multi-lane highway traffic flow

    Hodas, N O

    2003-01-01

    In heavy traffic with congested roadway the maximum traffic flow also depends on length of cars. This is deduced in a simple derivation suited for classroom demonstration as well as homework. The resulting equation demonstrates a new relation to an apparently unrelated area of physics, the maximum ship velocity (hull speed) and explains why traffic is sometimes faster on the slow lane on a congested multi-lane road.

  17. CMOS Image Sensor with a Built-in Lane Detector

    Li-Chen Fu; Hsien-Chein Cheng; Pei-Yung Hsiao; Shih-Shinh Huang

    2009-01-01

    This work develops a new current-mode mixed signal Complementary Metal-Oxide-Semiconductor (CMOS) imager, which can capture images and simultaneously produce vehicle lane maps. The adopted lane detection algorithm, which was modified to be compatible with hardware requirements, can achieve a high recognition rate of up to approximately 96% under various weather conditions. Instead of a Personal Computer (PC) based system or embedded platform system equipped with expensive high performance chi...

  18. Driver steering assistance: lane departure prevention for curvy roads using feedforward correction and BMI optimization

    Minoiu-Enache, N.; Mammar, S.; LUSETTI,B; Netto, M.

    2008-01-01

    This paper presents a steering assistance system that helps the driver to avoid unintended lane departure. Using a DC motor installed on the steering column, a steering control law takes action in situations of drifting off the lane. Furthermore, the steering control law provides lane keeping for straight as well as for curved roads until the driver recovers attention. In order to minimize a potential lane overshoot after the activation moment, and to reduce the curvature effect on the lane k...

  19. Reducing carbon emissions by introducing electric vehicle enhanced dedicated bus lanes

    Doolan, Ronan; Muntean, Gabriel-Miro

    2014-01-01

    Most cities have special lanes dedicated to buses, however these lanes are rarely used at full capacity. At the same time governments around the world are encouraging people to buy electric vehicles. This paper proposes the creation of electric vehicle enhanced dedicated bus lanes (E-DBL), by allowing electric vehicles access to bus lanes, in order to improve the use of road capacity. By opening bus lanes to electric vehicles, traffic congestion could be eased, the range ...

  20. MILLS B. LANE, JR. AND ENTERPRISE IN A NEW SOUTH

    Randall L. Patton

    2009-01-01

    Full Text Available For a century, Citizens & Southern Bank was a fixture in Georgia. In 1991, the C&S brand name disappeared in a merger with North Carolina National Bank. This was one of the bittersweet consequences of the slow, confusing swirl of bank deregulation after 1970, when institutions such as C&S simply disappeared, swallowed by the “winners” in the new competitive environment of interstate banking in the 1980s and 1990s. Even earlier, however, the Lane family had ceased to control the bank started by Mills Lane, Sr. in 1891. Mills B. Lane, Jr. was the last member of the Lane family to run C&S. After his retirement in 1973, Mills handpicked his successor and tried to retain some influence, but the bank began slipping away from the Lanes. By the early 80s, a decade before Hugh McColl’s NCNB acquired C&S, Mills Lane, Jr. was deeply alienated from the institution that had been, according to many, “Georgia’s cornerstone bank.”

  1. UPFLOWS IN THE CENTRAL DARK LANE OF SUNSPOT LIGHT BRIDGES

    We use high spatial and spectral resolution observations obtained with the CRisp Imaging SpectroPolarimeter at the Swedish 1 m Solar Telescope to analyze the velocity profile of granular light bridges (LBs) in a sunspot. We find upflows associated with the central dark lanes of the LBs. From bisectors in the Fe I 630.15 nm line we find that the magnitude of the upflows varies with height, with the strongest upflows being deeper in the atmosphere. Typical upflow velocities measured from the 70% bisector are around 500 m s-1 with peaks above 1 km s-1. The upflows in the central dark lane are surrounded by downflows of weaker magnitude, sometimes concentrated in patches with enhanced velocities reaching up to 1.1 km s-1. A small spatial offset between the upflows and the continuum dark lane is interpreted as a line-of-sight effect due to the elevated nature of the dark lane and the LB above the umbral surroundings. Our observations show that the central dark lane in granular LBs is not equivalent to the intergranular lanes of normal photospheric granulation that host convective downflows. These results support recent MHD simulations of magneto-convection in sunspot atmospheres.

  2. A new bus lane on urban expressway with no-bay bus stop

    Tian, Zhao; Jia, Limin

    2016-01-01

    The sharp increase in residents and vehicles causes heavy traffic pressure in many cities. To ease traffic congestion, it has been the common sense that we should develop public transit system. The priority of the bus appears particularly necessary with the rapid development of the public transport system. The bus lane is an important embodiment of the bus priority. Focusing on the problem of the unreasonable dedicated bus lane (DBL) under the lower ratio of buses, this paper proposed a new bus lane with limited physical length. And this bus lane can reduce the lane-changing conflict caused by the buses and cars running on roads without bus lanes. Based on the cellular automata (CA) traffic flow model and the lane-changing behavior of the vehicle including the optional lane-changing and the mandatory lane-changing, a three-lane traffic model with an isolated no-bay bus stop is proposed. The ordinary three-lane traffic without a bus lane and the cases of traffic with a DBL or the proposed bus lane are simulated, and the comparisons in the form of the fundamental diagrams are made among them. It is shown that the no-bay bus stop can act as a bottleneck on the traffic flow because of the mandatory lane-changing behavior. Under a certain ratio of the bus number to the total vehicles number, (1) the traffic with the proposed bus lane has less lane-changing conflict and can provide higher traffic capacity than the ordinary traffic without a bus lane, (2) compared with the DBL, the proposed bus lane is advantageous in easing congestion on the ordinary lanes when the traffic flow is high and can avoid unreasonable allocation of the road resources.

  3. Development of crash modification factors for changing lane width on roadway segments using generalized nonlinear models.

    Lee, Chris; Abdel-Aty, Mohamed; Park, Juneyoung; Wang, Jung-Han

    2015-03-01

    This study evaluates the effectiveness of changing lane width in reducing crashes on roadway segments. To consider nonlinear relationships between crash rate and lane width, the study develops generalized nonlinear models (GNMs) using 3-years crash records and road geometry data collected for all roadway segments in Florida. The study also estimates various crash modification factors (CMFs) for different ranges of lane width based on the results of the GNMs. It was found that the crash rate was highest for 12-ft lane and lower for the lane width less than or greater than 12ft. GNMs can extrapolate this nonlinear continuous effect of lane width and estimate the CMFs for any lane width, not only selected lane widths, unlike generalized linear models (GLMs) with categorical variables. The CMFs estimated using GNMs reflect that crashes are less likely to occur for narrower lanes if the lane width is less than 12ft whereas crashes are less likely to occur for wider lanes if the lane width is greater than 12ft. However, these effects varied with the posted speed limits as the effect of interaction between lane width and speed limit was significant. The estimated CMFs show that crashes are less likely to occur for lane widths less than 12ft than the lane widths greater than 12ft if the speed limit is higher than or equal to 40mph. It was also found from the CMFs that crashes at higher severity levels (KABC and KAB) are less likely to occur for lane widths greater or less than 12ft compared to 12-ft lane. The study demonstrates that the CMFs estimated using GNMs clearly reflect variations in crashes with lane width, which cannot be captured by the CMFs estimated using GLMs. Thus, it is recommended that if the relationship between crash rate and lane width is nonlinear, the CMFs are estimated using GNMs. PMID:25616033

  4. A Two-Lane Cellular Automata Model with Influence of Next-Nearest Neighbor Vehicle

    In this paper, we propose a new two-lane cellular automata model in which the influence of the next-nearest neighbor vehicle is considered. The attributes of the traffic system composed of fast-lane and slow-lane are investigated by the new traffic model. The simulation results show that the proposed two-lane traffic model can reproduce some traffic phenomena observed in real traffic, and that maximum flux and critical density are close to the field measurements. Moreover, the initial density distribution of the fast-lane and slow-lane has much influence on the traffic flow states. With the ratio between the densities of slow lane and fast lane increasing the lane changing frequency increases, but maximum flux decreases. Finally, the influence of the sensitivity coefficients is discussed.

  5. A Study of Lane Detection Algorithm for Personal Vehicle

    Kobayashi, Kazuyuki; Watanabe, Kajiro; Ohkubo, Tomoyuki; Kurihara, Yosuke

    By the word “Personal vehicle”, we mean a simple and lightweight vehicle expected to emerge as personal ground transportation devices. The motorcycle, electric wheelchair, motor-powered bicycle, etc. are examples of the personal vehicle and have been developed as the useful for transportation for a personal use. Recently, a new types of intelligent personal vehicle called the Segway has been developed which is controlled and stabilized by using on-board intelligent multiple sensors. The demand for needs for such personal vehicles are increasing, 1) to enhance human mobility, 2) to support mobility for elderly person, 3) reduction of environmental burdens. Since rapidly growing personal vehicles' market, a number of accidents caused by human error is also increasing. The accidents are caused by it's drive ability. To enhance or support drive ability as well as to prevent accidents, intelligent assistance is necessary. One of most important elemental functions for personal vehicle is robust lane detection. In this paper, we develop a robust lane detection method for personal vehicle at outdoor environments. The proposed lane detection method employing a 360 degree omni directional camera and unique robust image processing algorithm. In order to detect lanes, combination of template matching technique and Hough transform are employed. The validity of proposed lane detection algorithm is confirmed by actual developed vehicle at various type of sunshined outdoor conditions.

  6. Intelligent Lane Reservation System for Highway(s

    Ciprian Dobre

    2012-01-01

    Full Text Available Highways tend to get congested because of the increase in the number of cars travelling on them. There are two solutions to this. The first one, which is also expensive, consists in building new highways to support the traffic. A much cheaper alternative consists in the introduction of advanced intelligent traffic control systems to manage traffic and increase the efficiency of the already existing highways. Intelligent lane reservation system for highways (ILRSH is such a software control system. It is designed to assist and automate the use of a highway lane as a reserved lane. The idea is to allow and support drivers to travel at a speed higher, if in return they are willing to pay a small fee to reserve an empty virtual slot on the reserved lane. This slot is valid for a portion and of the highway and a time window, so each driver pays the fee depending thier its travelling needs. In return, drivers are guaranteed a congestion-free travel on that portion. In this paper, we present the proposed architecture of the ILRSH and its subsystems. The system is based on several proposed algorithms designed to assist the drivers, enter or exit the reserved lane, based on real-world driving observations. We present extensive simulation results showing the feasibility of the proposed approach, that can easily be implemented with little costs on already-existing highways, and the increase in traffic efficiency.

  7. Achievement of alternative configurations of vehicles on multiple lanes.

    Nishi, Ryosuke; Miki, Hiroshi; Tomoeda, Akiyasu; Nishinari, Katsuhiro

    2009-06-01

    Heavy traffic congestion occurs daily at merging sections on a highway. For relieving this congestion, possibility of alternative configuration of vehicles on multiple-lane road at a merging area is discussed in this paper. This is the configuration where no vehicles move aside on the other lane. It has merit in making a smooth merging at an intersection or a junction due to the so-called "zipper effect." We show, by developing a cellular automaton model for multiple lanes, that this configuration is achieved by simple local interactions between vehicles neighboring each other. The degree of the alternative configuration in terms of the spatial increase in parallel driving length is studied by using both numerical simulations and mean-field theory. We successfully construct a theoretical method for calculating this degree of the alternative configuration by using cluster approximation. It is shown that the theoretical results coincide with those of the simulations very well. PMID:19658576

  8. Managing Rush Hour Congestion with Lane Reversal and Tradable Credits

    Qing Li; Ziyou Gao

    2014-01-01

    Within the morning and evening rush hour, the two-way road flows are always unbalanced in opposite directions. In order to make full advantage of the existing lanes, the two-way road lane has to be reallocated to play the best role in managing congestion. On the other hand, an effective tradable credit scheme can help to reduce the traffic demand and improve fairness for all travelers. So as to alleviate the commute congestion in urban transportation network, a discrete bilevel programming mo...

  9. A Comparison of High Occupancy Vehicle, High Occupancy Toll, and Truck-Only Lanes in the Sacramento Region

    Rodier, Caroline J.; Johnston, Robert A.

    1999-01-01

    As the evidence mounts that HOV lanes will not produce expected reductions in congestion and emission, alternatives are being sought. High occupancy toll (HOT) lanes and truck only lanes are attractive alternatives. In this study, a region-wide system of new HOV lanes, HOT lanes, and truck only lanes m the Sacramento region are compared. The travel effects are simulated with the Sacramento regional travel demand model (SACMET96). The economic benefits for both personal travel and commercial v...

  10. Lane Keeping Assistance with Learning-Based Driver Model and Model Predictive Control

    Lefèvre, Stéphanie; Gao, Yiqi; Vasquez, Dizan; Tseng, H. Eric; Bajcsy, Ruzena; Borrelli, Francesco

    2014-01-01

    International audience This paper proposes a novel active Lane Keeping Assistance Systems (LKAS) which relies on a learning-based driver model. The driver model detects unintentional lane departures earlier than existing LKAS, and as a result the correction needed to keep the vehicle in the lane is smaller. When the controller has control of the car, the driver model estimates what the driver would do to keep the car in the lane, and the controller tries to reproduce that behavior as much ...

  11. A multi-objective model for the hazardous materials transportation problem based on lane reservation

    Zhou, 1 Zhen; Chu, Feng; Che, Ada; Mammar, Saïd

    2012-01-01

    This paper presents an application of the lane reservation strategy in the hazardous materials transportation. Once an accident of hazardous materials transportation happens, its effect is significant. Lane reservation can reduce the hazardous materials transportation risk enormously; however, it will also impact on the normal traffic. The proposed problem is to choose lanes to be reserved on the network and select the path for each hazardous materials shipment among the reserved lanes in ord...

  12. Lane changing and speed interaction on freeways: An analytical microscopic study

    Keyvan Ekbatani, M.; Grebert, V.; Daamen, W.; Knoop, V.L.

    2015-01-01

    Understanding the influence of lane changing manoeuvre on the capacity, stability, and breakdown of traffic flows is a crucial issue. In a recent study, four distinct lane change strategies on freeways have been empirically found: (1) Speed Leading; (2) Speed Leading with Overtaking; (3) Lane Leadin

  13. No reserved communication lanes for high energy

    Nico Pitrelli

    2006-06-01

    Full Text Available The American particle physics community is in jeopardy and may end up drowning in a boundless sea trying to grasp at non-existing funds, dragging US physics and science as a whole to the bottom. This is a price the most powerful and high-tech country of the world cannot afford, as warned by the editors of a report published in late April by the National Academy of Sciences1. Behind so much alarm is the International Linear Collider (ILC – a large particle accelerator facility which, according to the report, should be built on American territory, if research on the elementary constituents of nature is to survive in the United States. The ILC will probably cost a total of five hundred million dollars in the first five years, whereas billions will have to be invested in the subsequent seven years. Hardly impressive, however, if compared with the Superconducting Super Collider (SSC, the biggest and costliest machine ever conceived in the history of science. Devised to describe the first instants of the universe, as many will recall, the SSC project was severely hampered by political and bureaucratic plots in 1993, when the Clinton administration decided to halt work on the accelerator, after ten years and approximately two billion dollars already spent.

  14. Towards 400GBASE 4-lane Solution Using Direct Detection of MultiCAP Signal in 14 GHz Bandwidth per Lane

    Iglesias Olmedo, Miguel; Tianjian, Zuo; Jensen, Jesper Bevensee; Qiwen, Zhong; Xu, Xiaogeng; TAFUR MONROY, Idelfonso

    2013-01-01

    We report on an experimental demonstration of 102 Gbit/s transmission over a 15km single wavelength and polarization fiber link with 14GHz 3dB bandwidth. Novel multiband CAP signaling allows for a 4-lane 400GBASE long reach solution.

  15. The Problem of Reserved-lane for Hazardous Chemicals Transportation and Heuristic Algorithm

    Li Fuqing; Long Chi; Wu Naiqi

    2015-01-01

    Hazardous chemicals transportation requires a high-level of security assurance. It is an effective transport strategy that reserved-lanes are set in a transportation route to avoid accidents such as rear-end collision and crash. However, other vehicles will be inevitably influenced if a lane is set as the reserved-lane. Thus, how to minimize the influence by setting the reserved-lane becomes a problem needed to be studied. The mathematical programming model of the reserved-lane setting for ha...

  16. Fast lane recognition based on morphological multi-structure element model

    Lei, Tao; Fan, Yang-Yu; Huang, Lian-Bing

    2009-07-01

    This paper proposes a lane detection algorithm based on multi-structure element model of morphological. The innovative point of the algorithm lies in the facts that the flexible structure has the multi-structure elements that lane model features have, and that the algorithm adopts the morphological filtering principle to extract the pixels in the image, which is similar to the lane model. In the algorithm, the interested area is extracted by a model of trapezium from original image, which is detected by the operator of Canny, and the lanes are extracted by the structure elements, which have similar characteristics to that of lane model. Several lines are detected by Hough transformation, then the traffic lanes are reconstructed. Experiments show that this algorithm is simple and robust, and can efficiently detect the lane mask accurately and quickly.

  17. Microscopic simulation of multi-lane traffic under dynamic tolling and information feedback

    LIU Tian-liang; HUANG Hai-jun; TIAN Li-jun

    2009-01-01

    To investigate drivers' lane-changing behavior under different information feedback strategies, a microscopic traffic simulation based on the cellular automaton model was made on the typical freeway with a regular lane and a high-occupancy one. A new dynamic tolling scheme in terms of the real-time traffic condition on the high-occupancy lane was further designed to enhance the whole freeway's flow throughput. The results show that the mean velocity feedback strategy is generally more efficient than the travel time feedback strategy in correctly guiding drivers' lane choice behavior. Specifically, the toll level, lane-changing rate and freeway's throughput and congestion coefficient induced by the travel time feedback strategy oscillate with larger amplitude and longer period. In addition, the dynamic tolling scheme can make the high-occupancy lane less congested and maximize the freeway's throughput when the regular-lane inflow rate is larger than 0.45.

  18. Two-lane traffic rules for cellular automata: A systematic approach

    Nagel, K. [Los Alamos National Lab., NM (United States)]|[Forschungszentrum Juelich (Germany). Hoechsteleistungsrechenzentrum HLRZ; Wolf, D.E. [Forschungszentrum Juelich (Germany). Hoechstleistungsrechenzentrum HLRZ]|[Gerhard-Mercator-Univ., Duisburg (Germany). Theoretische Physik; Wagner, P. [Univ. zu Koeln (Germany). Zentrum Fuer Paralleles Rechnen]|[Deutsche Forschungsanstalt fuer Luft- und Raumfahrt, Koeln (Germany); Simon, P. [Los Alamos National Lab., NM (United States)

    1997-11-05

    Microscopic modeling of multi-lane traffic is usually done by applying heuristic lane changing rules, and often with unsatisfying results. Recently, a cellular automation model for two-lane traffic was able to overcome some of these problems and to produce a correct density inversion at densities somewhat below the maximum flow density. In this paper, the authors summarize different approaches to lane changing and their results, and propose a general scheme, according to which realistic lane changing rules can be developed. They test this scheme by applying it to several different lane changing rules, which, in spite of their differences, generate similar and realistic results. The authors thus conclude that, for producing realistic results, the logical structure of the lane changing rules, as proposed here, is at least as important as the microscopic details of the rules.

  19. Three-lane signatures of planets in planetesimal disks

    Demidova, Tatiana V

    2016-01-01

    In massive numerical experiments we show that a planet embedded in a planetesimal disk induces a characteristic three-lane "planetosignature" representing a pattern of three stellar-centric rings, one bright coorbital with the planet, and two dark gaps in the radial distribution of the particles. The gaps correspond to orbital resonances $2/1$ and $1/2$ with the planet. This theoretical prediction is in perfect agreement with recent ALMA observations of the disk of HL Tau.

  20. CMOS Image Sensor with a Built-in Lane Detector.

    Hsiao, Pei-Yung; Cheng, Hsien-Chein; Huang, Shih-Shinh; Fu, Li-Chen

    2009-01-01

    This work develops a new current-mode mixed signal Complementary Metal-Oxide-Semiconductor (CMOS) imager, which can capture images and simultaneously produce vehicle lane maps. The adopted lane detection algorithm, which was modified to be compatible with hardware requirements, can achieve a high recognition rate of up to approximately 96% under various weather conditions. Instead of a Personal Computer (PC) based system or embedded platform system equipped with expensive high performance chip of Reduced Instruction Set Computer (RISC) or Digital Signal Processor (DSP), the proposed imager, without extra Analog to Digital Converter (ADC) circuits to transform signals, is a compact, lower cost key-component chip. It is also an innovative component device that can be integrated into intelligent automotive lane departure systems. The chip size is 2,191.4 × 2,389.8 μm, and the package uses 40 pin Dual-In-Package (DIP). The pixel cell size is 18.45 × 21.8 μm and the core size of photodiode is 12.45 × 9.6 μm; the resulting fill factor is 29.7%. PMID:22573983

  1. CMOS Image Sensor with a Built-in Lane Detector

    Li-Chen Fu

    2009-03-01

    Full Text Available This work develops a new current-mode mixed signal Complementary Metal-Oxide-Semiconductor (CMOS imager, which can capture images and simultaneously produce vehicle lane maps. The adopted lane detection algorithm, which was modified to be compatible with hardware requirements, can achieve a high recognition rate of up to approximately 96% under various weather conditions. Instead of a Personal Computer (PC based system or embedded platform system equipped with expensive high performance chip of Reduced Instruction Set Computer (RISC or Digital Signal Processor (DSP, the proposed imager, without extra Analog to Digital Converter (ADC circuits to transform signals, is a compact, lower cost key-component chip. It is also an innovative component device that can be integrated into intelligent automotive lane departure systems. The chip size is 2,191.4 x 2,389.8 mm, and the package uses 40 pin Dual-In-Package (DIP. The pixel cell size is 18.45 x 21.8 mm and the core size of photodiode is 12.45 x 9.6 mm; the resulting fill factor is 29.7%.

  2. The nuclear dust lane of Circinus: collimation without a torus

    Mezcua, M; Fernández-Ontiveros, J A; Tristram, K R W

    2016-01-01

    In some AGN, nuclear dust lanes connected to kpc-scale dust structures provide all the extinction required to obscure the nucleus, challenging the role of the dusty torus proposed by the Unified Model. In this letter we show the pc-scale dust and ionized gas maps of Circinus constructed using sub-arcsec-accuracy registration of infrared VLT AO images with optical \\textit{Hubble Space Telescope} images. We find that the collimation of the ionized gas does not require a torus but is caused by the distribution of dust lanes of the host galaxy on $\\sim$10 pc scales. This finding questions the presumed torus morphology and its role at parsec scales, as one of its main attributes is to collimate the nuclear radiation, and is in line with interferometric observations which show that most of the pc-scale dust is in the polar direction. We estimate that the nuclear dust lane in Circinus provides $1/3$ of the extinction required to obscure the nucleus. This constitutes a conservative lower limit to the obscuration at t...

  3. A Real-Time Lane Detection Algorithm Based on Intelligent CCD Parameters Regulation

    Ping-shu Ge

    2012-01-01

    Full Text Available Lane departure warning system (LDWS has been regarded as an efficient method to lessen the damages of road traffic accident resulting from driver fatigue or inattention. Lane detection is one of the key techniques for LDWS. To overcome the contradiction between complexity of algorithm and the real-time requirement for vehicle onboard system, this paper introduces a new lane detection method based on intelligent CCD parameters regulation. In order to improve the real-time capability of the system, a CCD parameters regulating method is proposed which enhances the contrast between lane line and road surfaces and reduces image noise, so it lays a good foundation for the following lane detection. Hough transform algorithm is improved by selection and classification of seed points. Finally the lane line is extracted through some restrictions. Experimental results verify the effectiveness of the proposed method, which improves not only real-time capability but also the accuracy of the system.

  4. A new traffic model on compulsive lane-changing caused by off-ramp

    Xiao-He, Liu; Hung-Tang, Ko; Ming-Min, Guo; Zheng, Wu

    2016-04-01

    In the field of traffic flow studies, compulsive lane-changing refers to lane-changing (LC) behaviors due to traffic rules or bad road conditions, while free LC happens when drivers change lanes to drive on a faster or less crowded lane. LC studies based on differential equation models accurately reveal LC influence on traffic environment. This paper presents a second-order partial differential equation (PDE) model that simulates both compulsive LC behavior and free LC behavior, with lane-changing source terms in the continuity equation and a lane-changing viscosity term in the momentum equation. A specific form of this model focusing on a typical compulsive LC behavior, the ‘off-ramp problem’, is derived. Numerical simulations are given in several cases, which are consistent with real traffic phenomenon. Project supported by the National Natural Science Foundation of China (Grant Nos. 11002035 and 11372147).

  5. Visual guidance during bicycle steering through narrow lanes: a study in children.

    Vansteenkiste, Pieter; Cardon, Greet; Lenoir, Matthieu

    2015-05-01

    Recently, Vansteenkiste et al. (2013) explored how visual behaviour guides bicycle steering when cycling at different speeds through 15m long lanes of 10, 25 and 40cm wide. Participants were found to shift their gaze direction towards the end of the lanes at higher speeds, towards the near pathway on narrow lanes and more towards irrelevant areas on wider lanes. To investigate to what extent young learner bicyclists adapt their visual behaviour in a similar way as adults, the experiment was repeated with seven eight-year-old children, and results were compared to the adult data. Children were found to cycle slower through narrow lanes than adults. However, with increasing lane width and cycling speed, children made the same shifts of visual gaze direction as the adults. These results suggest that for a simple precision steering task, children are able to adopt a similar visual-motor strategy as adults, provided that they cycle at their own pace. PMID:25725423

  6. REBELLION: SECOND GENERATION BANGLADESHI IMMIGRANTS IN BRICK LANE BY MONICA ALI

    A. Nejat TÖNGÜR*

    2013-01-01

    Brick Lane is one of the few novels which reflect the lives of first and second generation Bangladeshi immigrants in Britain. Although Brick Lane focuses on Nazneen as central character, the novel provides very rich information about the life styles, work patterns, family structure, and cultural, social, economic and religious dynamics of the Bangladeshi community in Brick Lane. Ali also shows that the second-generation young Bangladeshis are distinct with their frequent clashes with their pa...

  7. A New Lane Departure Warning Algorithm Considering the Driver’s Behavior Characteristics

    Lun Hui Xu; San Gen Hu; Qiang Luo

    2015-01-01

    In order to meet the driving safety warning required for different driver types and situations, a new lane departure warning (LDW) algorithm was proposed. Its adaptability is much better through setting the different thresholds of time to lane crossing (TLC) using fuzzy control method for driver with different driving behaviors in different lanes and different vehicle movements. To ensure the accuracy of computation of TLC under the different actual driving scenarios, the algorithm was establ...

  8. Differentiated Road Pricing, Express Lanes and Carpools: Exploiting Heterogeneous Preferences in Policy Design

    Kenneth A. Small; Clifford Winston; Jia Yan

    2005-01-01

    In the face of rising congestion on the nation's road system, policymakers have explored ways to reduce travel delays. One approach has been to allocate reserved lanes, called high-occupancy-vehicle (HOV) lanes, to vehicles carrying two or more people. A recent innovation is to allow solo drivers to use the HOV lanes if they pay a toll. These so-called high-occupancy-toll (HOT) lanes can be found in Los Angeles, San Diego, Houston, and Minneapolis and are under consideration in several other ...

  9. Development of 8-lane PCI-Express protocol using VHDL

    K. Harish

    2011-11-01

    Full Text Available Flosolver Mk 8 is the latest family member of the Flosolver series of parallel computers in CSIR-NAL that is currently being developed, to have a performance of 10 TFLOPS with 1024 processors in it. It is based on distributed memory concept, using quad core xeon processors[11]. Each cluster consists of 8 processors, a FPGA based Floswitch, and 4 PCI cards. The inter Cluster communication is carried out through optical transceivers to provide high speed communication. PCI is used for interface between the server and the FloSwitch. Unlike any other switch, the Floswitch has the capability of performing information processing operation which is a unique feature, along with message passing[12]. To this existing system the project intends to replace the PCI card with 8- lane PCI-Express add-on card. The PCI-Express defines a line rate of 2.5Gbps per lane. The basic goal of this project entitled “Development of PCI Express protocol using VHDL” is to Design and Develop a PCI-Express protocol for a 8x PCI-e card, with an optical transceiver and DPM (Dual Port Memory as an external interfaces. The development includes the generation of 8 x PCI-e cores and interfacing the core for optical transaction and also for the DPM transaction. The PCI-Express add-on card contains a FPGA (Virtex V– XC5VLX110T and the card supports 8X lane. FPGA provides an interface between the PCI-Express signals, the DPM and the optical transceiver module. The protocol has to be developed using VHDL and simulated using model sim 6.1f

  10. A New Paradigm in User Equilibrium-Application in Managed Lane Pricing

    Asapol Sinprasertkool

    2011-04-01

    Full Text Available Ineffective use of the High-Occupancy-Vehicle (HOV lanes has the potential to decrease the overall roadway throughput during peak periods. Excess capacity in HOV lanes during peak periods can be made available to other types of vehicles, including single occupancy vehicles (SOV for a price (toll. Such dual use lanes are known as “Managed Lanes.” The main purpose of this research is to propose a new paradigm in user equilibrium to predict the travel demand for determining the optimal fare policy for managed lane facilities. Depending on their value of time, motorists may choose to travel on Managed Lanes (ML or General Purpose Lanes (GPL. In this study, the features in the software called Toll Pricing Modeler version 4.3 (TPM-4.3 are described. TPM-4.3 is developed based on this new user equilibrium concept and utilizes it to examine various operating scenarios. The software has two built-in operating objective options: 1 what would the ML operating speed be for a specified SOV toll, or 2 what should the SOV toll be for a desired minimum ML operating speed. A number of pricing policy scenarios are developed and examined on the proposed managed lane segment on Interstate 30 (I-30 in Grand Prairie, Texas. The software provides quantitative estimates of various factors including toll revenue, emissions and system performance such as person movement and traffic speed on managed and general purpose lanes. Overall, among the scenarios examined, higher toll rates tend to generate higher toll revenues, reduce overall CO and NOx emissions, and shift demand to general purpose lanes. On the other hand, HOV preferential treatments at any given toll level tend to reduce toll revenue, have no impact on or reduce system performance on managed lanes, and increase CO and NOx emissions.

  11. Automatic lane keeping of a vehicle based on perception net

    Boo, Kwangsuck; Jung, Moonyoung

    2000-10-01

    The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A predictive control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder through the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in forward and backward direction in such a way to satisfy the given constraint condition, maintain consistency, reduce the uncertainties, and guarantee robustness. A series of experiments was conducted to evaluate the control performance, in which a car like robot was utilized to quit unwanted safety problem. As the results, the robot was keeping very well a given lane with arbitrary shape at moderate speed.

  12. A bioinformatics approach for determining sample identity from different lanes of high-throughput sequencing data.

    Rachel L Goldfeder

    Full Text Available The ability to generate whole genome data is rapidly becoming commoditized. For example, a mammalian sized genome (∼3Gb can now be sequenced using approximately ten lanes on an Illumina HiSeq 2000. Since lanes from different runs are often combined, verifying that each lane in a genome's build is from the same sample is an important quality control. We sought to address this issue in a post hoc bioinformatic manner, instead of using upstream sample or "barcode" modifications. We rely on the inherent small differences between any two individuals to show that genotype concordance rates can be effectively used to test if any two lanes of HiSeq 2000 data are from the same sample. As proof of principle, we use recent data from three different human samples generated on this platform. We show that the distributions of concordance rates are non-overlapping when comparing lanes from the same sample versus lanes from different samples. Our method proves to be robust even when different numbers of reads are analyzed. Finally, we provide a straightforward method for determining the gender of any given sample. Our results suggest that examining the concordance of detected genotypes from lanes purported to be from the same sample is a relatively simple approach for confirming that combined lanes of data are of the same identity and quality.

  13. Real-time Lane Detection on Suburban Streets using Visual Cue Integration

    Shehan Fernando

    2014-04-01

    mask is generated using road chromaticity values estimated from CIE L*a*b* colour transformation. Extraneous points around lane boundary lines are then removed by an outlier removal procedure based on studentized residuals. The lane boundary lines are then modelled with Bezier spline curves. To validate the algorithm, extensive experimental evaluation was carried out on suburban streets and the results are presented.

  14. Safety-collision transition induced by lane changing in traffic flow

    We study the traffic behavior when a vehicle changes from the first lane to the second lane on a two-lane highway. We apply the optimal velocity model to the vehicular motion. If the incoming vehicle does not decelerate successfully, it crashes into the vehicle ahead. On the other hand, if the headway between the incoming vehicle and the vehicle behind on the second lane is not long sufficiently, the rear vehicle may come into collision with the incoming vehicle. The safety-collision transition occurs by changing the lane. The dynamical transition depends highly on the vehicular speed, the sensitivity, and the headway. We derive the phase diagram (or region map) for the safety-collision transition.

  15. Lattice hydrodynamic modeling of two-lane traffic flow with timid and aggressive driving behavior

    Sharma, Sapna

    2015-03-01

    In this paper, a new two-lane lattice hydrodynamic traffic flow model is proposed by considering the aggressive or timid characteristics of driver's behavior. The effect of driver's characteristic on the stability of traffic flow is examined through linear stability analysis. It is shown that for both the cases of lane changing or without lane changing the stability region significantly enlarges (reduces) as the proportion of aggressive (timid) drivers increases. To describe the propagation behavior of a density wave near the critical point, nonlinear analysis is conducted and mKdV equation representing kink-antikink soliton is derived. The effect of anticipation parameter with more aggressive (timid) drivers is also investigated and found that it has a positive (negative) effect on the stability of two-lane traffic flow dynamics. Simulation results are found consistent with the theoretical findings which confirm that the driver's characteristics play a significant role in a two-lane traffic system.

  16. Driver’s Awareness and Lane Changing Maneuver in Traffic Flow based on Cellular Automaton Model

    Kohei Arai

    2015-08-01

    Full Text Available Effect of driver’s awareness (e.g., to estimate the speed and arrival time of another vehicle on the lane changing maneuver is discussed. “Scope awareness” is defined as the visibility which is required for the driver to make a visual perception about road condition and the speed of vehicle that appears in the target lane for lane changing in the road. Cellular automaton based simulation model is created and applied to simulation studies for driver awareness behavior. This study clarifies relations between the lane changing behavior and the scope awareness parameter that reflects driver behavior. Simulation results show that the proposed model is valid for investigation of the important features of lane changing maneuver.

  17. The Problem of Reserved-lane for Hazardous Chemicals Transportation and Heuristic Algorithm

    Li Fuqing

    2015-01-01

    Full Text Available Hazardous chemicals transportation requires a high-level of security assurance. It is an effective transport strategy that reserved-lanes are set in a transportation route to avoid accidents such as rear-end collision and crash. However, other vehicles will be inevitably influenced if a lane is set as the reserved-lane. Thus, how to minimize the influence by setting the reserved-lane becomes a problem needed to be studied. The mathematical programming model of the reserved-lane setting for hazardous chemicals transportation is established in this paper. According to the characteristics of the problem, the heuristic algorithm based on Dijkstra algorithm is proposed. This algorithm is a simple and intelligible, satisfactory solution that can be obtained in polynomials.

  18. Extended-search, Bézier Curve-based Lane Detection and Reconstruction System for an Intelligent Vehicle

    Xiaoyun Huang

    2015-09-01

    Full Text Available To improve the real-time performance and detection rate of a Lane Detection and Reconstruction (LDR system, an extended-search-based lane detection method and a Bézier curve-based lane reconstruction algorithm are proposed in this paper. The extended search-based lane detection method is designed to search boundary blocks from the initial position, in an upwards direction and along the lane, with small search areas including continuous search, discontinuous search and bending search in order to detect different lane boundaries. The Bézier curve-based lane reconstruction algorithm is employed to describe a wide range of lane boundary forms with comparatively simple expressions. In addition, two Bézier curves are adopted to reconstruct the lanes’ outer boundaries with large curvature variation. The lane detection and reconstruction algorithm — including initial-blocks’ determining, extended search, binarization processing and lane boundaries’ fitting in different scenarios — is verified in road tests. The results show that this algorithm is robust against different shadows and illumination variations; the average processing time per frame is 13 ms. Significantly, it presents an 88.6% high-detection rate on curved lanes with large or variable curvatures, where the accident rate is higher than that of straight lanes.

  19. Gin Lane: did Hogarth know about fetal alcohol syndrome?

    Abel, E L

    2001-01-01

    Medical historians have searched for evidence that the characteristics of fetal alcohol syndrome (FAS) were recognized long before its modern description in 1973. This search has often focused on the 'gin epidemic' in 18th century London, and especially William Hogarth's Gin Lane, which some authors allege reflects an awareness of the facial characteristics of the syndrome. While the 'gin epidemic' undoubtedly resulted in the increased birth of weak and sickly children, claims about Hogarth's awareness of the stigmata of the FAS are unfounded. The birth of weak and sickly children, and the high infant mortality rates associated with this period, long preceded the 'gin epidemic' and were primarily due to disease, starvation, exposure, and deliberate infanticide. PMID:11259209

  20. PREVAILING SATURATION FLOW RATE FOR LANE GROUPS IN AN URBAN AREA

    Stephen Arhin

    2016-06-01

    Full Text Available This study focused on determining the prevailing Saturation Flow Rate (SFR for specific lane groups in an urban area: District of Columbia (DC. The lane groups considered were Through (T, shared Through and Right (TR, shared Through and Left (TL, and exclusive Left turn (L lane groups. These SFR values could then be used to calculate the local base SFR. The study determined the prevailing SFR for these lane groups based on data collected at 81 intersections. The hypothesis that the mean SFRs for all the lane groups are different was tested at a 5% level of significance. From the results, the mean prevailing SFR for the T, TR, TL and L lane groups were 1,559, 1,461, 1,566 and 1,460 vphpl respectively. Those prevailing SFRs can be used for planning analyses in the District of Columbia. The results also indicated that these mean prevailing SFRs are statistically similar at 95% confidence interval. Based on the results, a local base SFR for the City can be determined for each lane group.

  1. The Research of the Lane Detection Algorithm Base on Vision Sensor

    Li Sha Sha

    2013-06-01

    Full Text Available The intelligent vehicle is an important area country in recent years of painstaking research in Intelligent Transportation System, which become the focus of the study, based on the visual structure of the road environment recognition. Aiming at the robust and real time problems of lane detection in the visual navigation system of intelligent vehicles, a robust lane detection method is proposed for the structured road. It can provide for intelligent vehicle automatically to maintain lane and changing lanes traveling lane information necessary to make smart vehicle to achieve a smooth, safe driving. Due to the complexity of the road itself, the complexity of the road image, Therefore, the pre-road established certain assumptions and these assumptions and the detection algorithm is combined to further improve the algorithm efficiency. Simulation test of the collected road images results show that the lane detection method designed in this study is stable enough to show the lane Position for engineering application not matter in good or poor illumination road condition.

  2. Comprehensive and Practical Vision System for Self-Driving Vehicle Lane-Level Localization.

    Du, Xinxin; Tan, Kok Kiong

    2016-05-01

    Vehicle lane-level localization is a fundamental technology in autonomous driving. To achieve accurate and consistent performance, a common approach is to use the LIDAR technology. However, it is expensive and computational demanding, and thus not a practical solution in many situations. This paper proposes a stereovision system, which is of low cost, yet also able to achieve high accuracy and consistency. It integrates a new lane line detection algorithm with other lane marking detectors to effectively identify the correct lane line markings. It also fits multiple road models to improve accuracy. An effective stereo 3D reconstruction method is proposed to estimate vehicle localization. The estimation consistency is further guaranteed by a new particle filter framework, which takes vehicle dynamics into account. Experiment results based on image sequences taken under different visual conditions showed that the proposed system can identify the lane line markings with 98.6% accuracy. The maximum estimation error of the vehicle distance to lane lines is 16 cm in daytime and 26 cm at night, and the maximum estimation error of its moving direction with respect to the road tangent is 0.06 rad in daytime and 0.12 rad at night. Due to its high accuracy and consistency, the proposed system can be implemented in autonomous driving vehicles as a practical solution to vehicle lane-level localization. PMID:26992020

  3. An Optimization Model for the Selection of Bus-Only Lanes in a City

    Chen, Qun

    2015-01-01

    The planning of urban bus-only lane networks is an important measure to improve bus service and bus priority. To determine the effective arrangement of bus-only lanes, a bi-level programming model for urban bus lane layout is developed in this study that considers accessibility and budget constraints. The goal of the upper-level model is to minimize the total travel time, and the lower-level model is a capacity-constrained traffic assignment model that describes the passenger flow assignment ...

  4. A Bioinformatics Approach for Determining Sample Identity from Different Lanes of High-Throughput Sequencing Data

    Rachel L Goldfeder; Parker, Stephen C.J.; Ajay, Subramanian S.; Hatice Ozel Abaan; Margulies, Elliott H.

    2011-01-01

    The ability to generate whole genome data is rapidly becoming commoditized. For example, a mammalian sized genome (∼3Gb) can now be sequenced using approximately ten lanes on an Illumina HiSeq 2000. Since lanes from different runs are often combined, verifying that each lane in a genome's build is from the same sample is an important quality control. We sought to address this issue in a post hoc bioinformatic manner, instead of using upstream sample or "barcode" modifications. We rely on the ...

  5. Driver’s Awareness and Lane Changing Maneuver in Traffic Flow based on Cellular Automaton Model

    Kohei Arai; Steven Ray Sentinuwo

    2015-01-01

    Effect of driver’s awareness (e.g., to estimate the speed and arrival time of another vehicle) on the lane changing maneuver is discussed. “Scope awareness” is defined as the visibility which is required for the driver to make a visual perception about road condition and the speed of vehicle that appears in the target lane for lane changing in the road. Cellular automaton based simulation model is created and applied to simulation studies for driver awareness behavior. This study clarifies re...

  6. A Bioinformatics Approach for Determining Sample Identity from Different Lanes of High-Throughput Sequencing Data

    Goldfeder, Rachel L.; Stephen C J Parker; Ajay, Subramanian S.; Ozel Abaan, Hatice; Margulies, Elliott H.

    2011-01-01

    The ability to generate whole genome data is rapidly becoming commoditized. For example, a mammalian sized genome (∼3Gb) can now be sequenced using approximately ten lanes on an Illumina HiSeq 2000. Since lanes from different runs are often combined, verifying that each lane in a genome's build is from the same sample is an important quality control. We sought to address this issue in a post hoc bioinformatic manner, instead of using upstream sample or “barcode” modifications. We rely on the ...

  7. Effects of turning and through lane sharing on traffic performance at intersections

    Li, Xiang; Sun, Jian-Qiao

    2016-02-01

    Turning vehicles strongly influence traffic flows at intersections. Effective regulation of turning vehicles is important to achieve better traffic performance. This paper studies the impact of lane sharing and turning signals on traffic performance at intersections by using cellular automata. Both right-turn and left-turn lane sharing are studied. Interactions between vehicles and pedestrians are considered. The transportation efficiency, road safety and energy economy are the traffic performance metrics. Extensive simulations are carried out to study the traffic performance indices. It is observed that shared turning lanes and permissive left-turn signal improve the transportation efficiency and reduce the fuel consumption in most cases, but the safety is usually sacrificed. It is not always beneficial for the through vehicles when they are allowed to be in the turning lanes.

  8. Open Access!: Review of Online Statistics: An Interactive Multimedia Course of Study by David Lane

    Samuel L. Tunstall

    2016-01-01

    Full Text Available David M. Lane (project leader. Online Statistics Education: An Interactive Multimedia Course of Study (http://onlinestatbook.com/ Also: David M. Lane (primary author and editor, with David Scott, Mikki Hebl, Rudy Guerra, Dan Osherson, and Heidi Zimmer. Introduction to Statistics. Online edition (http://onlinestatbook.com/Online_Statistics_Education.pdf, 694 pp. It is rare that students receive high-quality textbooks for free, but David Lane's Online Statistics: An Interactive Multimedia Course of Study permits precisely that. This review gives an overview of the many features in Lane's online textbook, including the Java Applets, the textbook itself, and the resources available for instructors. A discussion of uses of the site, as well as a comparison of the text to alternative online statistics textbooks, is included.

  9. 77 FR 8253 - Notice of Proposed Settlement Agreement and Opportunity for Public Comment: Hidden Lane Landfill...

    2012-02-14

    ... AGENCY Notice of Proposed Settlement Agreement and Opportunity for Public Comment: Hidden Lane Landfill... Landfill Superfund Site, Sterling, Loudoun County, Virginia (``Site''). DATES: Written comments on the..., Hazardous Site Cleanup Division, Region III. BILLING CODE 6560-50-P...

  10. Shipping Fairways, Lanes, and Zones for US waters as of June 2013

    National Oceanic and Atmospheric Administration, Department of Commerce — Various shipping zones delineate activities and regulations for marine vessel traffic. Traffic lanes define specific traffic flow, while traffic separation zones...

  11. Lane Changing Trajectory Planning and Tracking Controller Design for Intelligent Vehicle Running on Curved Road

    Lie Guo

    2014-01-01

    Full Text Available To enhance the active safety and realize the autonomy of intelligent vehicle on highway curved road, a lane changing trajectory is planned and tracked for lane changing maneuver on curved road. The kinematics model of the intelligent vehicle with nonholonomic constraint feature and the tracking error model are established firstly. The longitudinal and lateral coupling and the difference of curvature radius between the outside and inside lane are taken into account, which is helpful to enhance the authenticity of desired lane changing trajectory on curved road. Then the trajectory tracking controller of closed-loop control structure is derived using integral backstepping method to construct a new virtual variable. The Lyapunov theory is applied to analyze the stability of the proposed tracking controller. Simulation results demonstrate that this controller can guarantee the convergences of both the relative position tracking errors and the position tracking synchronization.

  12. On Nonlinear Asymptotic Stability of the Lane-Emden Solutions for the Viscous Gaseous Star Problem

    Luo, Tao; Xin, Zhouping; Zeng, Huihui

    2015-01-01

    This paper proves the nonlinear asymptotic stability of the Lane-Emden solutions for spherically symmetric motions of viscous gaseous stars if the adiabatic constant $\\gamma$ lies in the stability range $(4/3, 2)$. It is shown that for small perturbations of a Lane-Emden solution with same mass, there exists a unique global (in time) strong solution to the vacuum free boundary problem of the compressible Navier-Stokes-Poisson system with spherical symmetry for viscous stars, and the solution ...

  13. Congestive Traffic Failure: The Case for High-Occupancy and Express Toll Lanes in Canadian Cities

    Benjamin Dachis

    2011-01-01

    Congestion on Canadian highways is having a significant negative economic impact on major Canadian cities. Rather than face the political challenge of introducing road tolls to discourage traffic, governments have chosen to build carpool lanes on urban highways, despite evidence that these lanes have limited effectiveness in curbing congestion. Policymakers in major Canadian cities need realistic options for reducing the economic cost of congestion and increasing revenue for transportation in...

  14. Dynamic bus lanes in Sweden – a pre-study : PROVDYK – Final report

    Olstam, Johan; Häll, Carl-Henrik; Smith, Göran; Habibovic, Azra; Anund, Anna

    2015-01-01

    Dedicated bus lanes and bus streets have, in recent years, become common measures for prioritisation of public transport. By ensuring free path along routes, they increase average speed and travel time reliability of buses. However, a major drawback is that the total traffic capacities of the roads decrease. Hence, these measures are only suitable when the total traffic flow is low enough to allow for a reduction of lanes; if it is possible to reroute adjacent traffic; or if it is possible to...

  15. Effect of Driver Scope Awareness in the Lane Changing Maneuvers Using Cellular Automaton Model

    Kohei Arai; Steven Ray Sentinuwo

    2013-01-01

    This paper investigated the effect of drivers’ visibility and their perception (e.g., to estimate the speed and arrival time of another vehicle) on the lane changing maneuver. The term of scope awareness was used to describe the visibility required by the driver to make a perception about road condition and the speed of vehicle that exist in that road. A computer simulation model was conducted to show this driver awareness behavior. This studying attempt to precisely catching the lane changin...

  16. Event-Based Modeling of Driver Yielding Behavior to Pedestrians at Two-Lane Roundabout Approaches

    Salamati, Katayoun; Schroeder, Bastian J.; Geruschat, Duane R.; Rouphail, Nagui M.

    2014-01-01

    Unlike other types of controlled intersections, drivers do not always comply with the “yield to pedestrian” sign at the roundabouts. This paper aims to identify the contributing factors affecting the likelihood of driver yielding to pedestrians at two-lane roundabouts. It further models the likelihood of driver yielding based on these factors using logistic regression. The models have been applied to 1150 controlled pedestrian crossings at entry and exit legs of two-lane approaches of six rou...

  17. Driver assistance system for lane departure avoidance by steering and differential braking

    Minoiu-Enache, N.; Mammar, S.; GLASER, S; LUSETTI,B

    2010-01-01

    Lane departure avoidance systems assist actively the driver during inattention or drowsiness and increase driving safety. Most of the lane departure avoidance systems use for the lateral control of the vehicle in closed loop a DC motor similar to the electrical powered steering (EPS) assistance. Important difficulties and limits of this approach are the shared control with the driver on the steering wheel and the vehicle handling at limits. In this paper a combined lateral control using a DC ...

  18. Solution of the Lane-Emden Equation Using the Bernstein Operational Matrix of Integration

    Narayan Kumar; Pandey, Rajesh K.; Carlo Cattani

    2011-01-01

    Lane-Emden's equation has fundamental importance in the recent analysis of many problems in relativity and astrophysics including some models of density profiles for dark matter halos. An efficient numerical method is presented for linear and nonlinear Lane-Emden-type equations using the Bernstein polynomial operational matrix of integration. The proposed approach is different from other numerical techniques as it is based on the Bernstein polynomial integration matrix. Some illustrative exam...

  19. Influences of overtaking on two-lane traffic with signals

    Chen, Chen; Chen, Jianqiao; Guo, Xiwei

    2010-01-01

    Based on the cellular automata method (CA method), two-lane traffic flow with the consideration of overtaking is investigated. Discrete equations are proposed to describe the traffic dynamics by using the rules of CA model. Influences of signal cycle time ( ts) and vehicular density (ρ) on the mean velocity and mean overtaking times of the traffic flow are discussed. The effects of slow vehicles and road barricades on the traffic flow are also studied. Simulation results shows that the vehicular density and the signal cycle time have significant influences on the traffic flow. The mean velocity of the traffic flow could keep a comparatively large value when ρ≤0.45. For a certain value of ρ, displays a serrated fluctuation with ts. Therefore, there may exist a certain combination of ρ and ts which optimizes the traffic flow efficiency. As compared with the results in Nagatani (2009) [7], the model proposed here and the simulation results which took into account the effects of signal cycle time, slow vehicles, and road barricades on the traffic flow with overtaking allowed, can reflect the situation of traffic flow in a more realistic way.

  20. Embedded star formation in S4G galaxy dust lanes

    Star-forming regions that are visible at 3.6 μm and Hα but not in the u, g, r, i, z bands of the Sloan Digital Sky Survey are measured in five nearby spiral galaxies to find extinctions averaging ∼3.8 mag and stellar masses averaging ∼5 × 104 M ☉. These regions are apparently young star complexes embedded in dark filamentary shock fronts connected with spiral arms. The associated cloud masses are ∼107 M ☉. The conditions required to make such complexes are explored, including gravitational instabilities in spiral-shocked gas and compression of incident clouds. We find that instabilities are too slow for a complete collapse of the observed spiral filaments, but they could lead to star formation in the denser parts. Compression of incident clouds can produce a faster collapse but has difficulty explaining the semi-regular spacing of some regions along the arms. If gravitational instabilities are involved, then the condensations have the local Jeans mass. Also in this case, the near-simultaneous appearance of equally spaced complexes suggests that the dust lanes, and perhaps the arms too, are relatively young.

  1. Comparison of color image segmentations for lane following

    Sandt, Frederic; Aubert, Didier

    1993-05-01

    For ten years, unstructured road following has been the subject of many studies. Road following must support the automatic navigation, at reasonable speed, of mobile robots on irregular paths and roads, with unhomogeneous surfaces and under variable lighting conditions. Civil and military applications of this technology include transportation, logistics, security and engineering. The definition of our lane following system requires an evaluation of the existing technologies. Although the various operational systems converge on a color perception and a region segmentation optimizing discrimination and stability respectively, the treatments and performances vary. In this paper, the robustness of four operational systems and two connected techniques are compared according to common evaluation criteria. We identify typical situations which constitute a basis for the realization of an image database. We describe the process of experimentation conceived for the comparative analysis of performances. The analytical results are useful in order to infer a few optimal combinations of techniques driven by the situations, and to define the present limits of the color perception's validity.

  2. Evaluating the Safety Effects of Bicycle Lanes in New York City

    Srinivasan, Raghavan; McKnight, Claire E.; Ewing, Reid; Roe, Matthew

    2012-01-01

    Objectives. We evaluated the effects of on-street bicycle lanes installed prior to 2007 on different categories of crashes (total crashes, bicyclist crashes, pedestrian crashes, multiple-vehicle crashes, and injurious or fatal crashes) occurring on roadway segments and at intersections in New York City. Methods. We used generalized estimating equation methodology to compare changes in police-reported crashes in a treatment group and a comparison group before and after installation of bicycle lanes. Our study approach allowed us to control confounding factors, such as built environment characteristics, that cannot typically be controlled when a comparison group is used. Results. Installation of bicycle lanes did not lead to an increase in crashes, despite the probable increase in the number of bicyclists. The most likely explanations for the lack of increase in crashes are reduced vehicular speeds and fewer conflicts between vehicles and bicyclists after installation of these lanes. Conclusions. Our results indicate that characteristics of the built environment have a direct impact on crashes and that they should thus be controlled in studies evaluating traffic countermeasures such as bicycle lanes. To prevent crashes at intersections, we recommend installation of “bike boxes” and markings that indicate the path of bicycle lanes across intersections. PMID:22095351

  3. PSO Algorithm Particle Filters for Improving the Performance of Lane Detection and Tracking Systems in Difficult Roads

    Wen-Chang Cheng

    2012-12-01

    Full Text Available In this paper we propose a robust lane detection and tracking method by combining particle filters with the particle swarm optimization method. This method mainly uses the particle filters to detect and track the local optimum of the lane model in the input image and then seeks the global optimal solution of the lane model by a particle swarm optimization method. The particle filter can effectively complete lane detection and tracking in complicated or variable lane environments. However, the result obtained is usually a local optimal system status rather than the global optimal system status. Thus, the particle swarm optimization method is used to further refine the global optimal system status in all system statuses. Since the particle swarm optimization method is a global optimization algorithm based on iterative computing, it can find the global optimal lane model by simulating the food finding way of fish school or insects under the mutual cooperation of all particles. In verification testing, the test environments included highways and ordinary roads as well as straight and curved lanes, uphill and downhill lanes, lane changes, etc. Our proposed method can complete the lane detection and tracking more accurately and effectively then existing options.

  4. Trifoliata hybrids rootstocks for 'Lane Late' navel orange in Spain

    Pilar Legua

    2011-10-01

    Full Text Available Carrizo citrange [Citrus sinensis (L. Osb. × Poncirus trifoliata (L. Raf.] and Cleopatra mandarin (C. reshni Hort. ex Tan. are the most important rootstocks used in Spain, but they are problematic and it is necessary to search for new rootstocks with better all-round performance. The performance of 'Lane Late' navel orange [Citrus sinensis (L. Osb] on ten rootstocks was determined in the South of the province of Alicante (Spain. They are Carrizo citrange, Cleopatra mandarin and eight new hybrids obtained at the Instituto Valenciano de Investigaciones Agrarias in Valencia (Spain: 020324 [Troyer citrange (C. sinensis × P. trifoliata × Cleopatra mandarin], Forner-Alcaide 418 (F&A 418 [Troyer citrange × common mandarin (C. deliciosa Ten.], Forner-Alcaide 13 (F&A 13, 030118, 030127 and 030131 (Cleopatra mandarin × P. trifoliata and 030212 and 030230 (Cleopatra mandarin × Troyer citrange. Soil is clay loam, with pH 8.5 and electric conductivity in the saturation extract at 25ºC of 5.79 mS cm-1. Yield was weighed during the first nine harvests, fruit quality was determined in the last three. Pre-harvest fruit-drop was controlled for the 4th until 9th harvests. The trees of 'Lane Late' navel budded on Cleopatra mandarin were the tallest (2.5 m and F&A 418 (1.6 m the shortest of all rootstocks tested. Trees on 030131 hybrid and Carrizo citrange rootstocks had the highest mean yield (81.2 and 80.3 kg per tree per year respectively, while trees on F&A 418 produced the lowest mean yield (22.3 kg per tree per year. Trees on 030131, 020324 and 030212 had the highest yield efficiency as total cumulative yield per cubic meter of canopy volume (62.1, 58.7 and 55.9 kg m-3 respectively whereas trees on 030127, F&A 418 and Cleopatra mandarin had lower yield efficiencies (45.0, 44.4 and 38.6 kg m-3, respectively. Pre-harvest fruit-drop was lower in trees grafted on Cleopatra mandarin (24.62 % and on 030212 (26.61 %, and was also low on F&A 418 (27

  5. Real-time lane departure warning system based on principal component analysis of grayscale distribution and risk evaluation model

    张伟伟; 宋晓琳; 张桂香

    2014-01-01

    A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.

  6. Socio-demographic impacts on lane-changing response time and distance in work zone with Drivers' Smart Advisory System

    Qing Li

    2015-10-01

    Full Text Available Lane-changing behavior is an important component of traffic simulation. A lane-changing action is normally confined to a decision-making process of the task, and the action itself is sometimes assumed as an instantaneous event. Besides, the lane-changing behavior is based mostly on observable positions and speeds of other vehicles, rather than on vehicles' intentions. In practice, changing one lane requires about 5–6 s to complete. Existing lane-changing models do not comprehensively consider drivers' response to work zone lane-changing signs (or other related messages, if any. Furthermore, drivers' socio-demographics are normally not taken into account. With regard to this, fuzzy logic-based lane-changing models that consider drivers' socio-demographics were developed to improve the realism of lane-changing maneuvers in work zones. Drivers' Smart Advisory System (DSAS messages were provided as one of the scenarios. Drivers' responses, including reactions to work zone signs and DSAS messages, and actions to change lane, were investigated. Drivers' socio-demographic factors were primary independent variables, while Lane-Changing Response Time (LCRT and Distance (LCRD were defined as output variables. The model validation process yielded acceptable error ranges. To illustrate how these models can be used in traffic simulation, the LCRT and LCRD in work zones were estimated for five geo-locations with different socio-demographic specifications. Results show that the DSAS is able to instruct all drivers to prepare and change lanes earlier, thereby shortening the duration of changing lanes. Educational background and age are essential variables, whereas the impacts of gender on the output variables are indistinctive.

  7. Absence of Metastable States in Two-Lane Traffic Flow Models With Slow-To-Start Rule

    Moussa, N

    2006-01-01

    It is widely known that one-lane traffic models with slow-to-start rule exhibit phase separation and metastability. In this paper, we show that no metastable states exist in the two-lane version of the VDR model. We show also that the structure of the steady state as well as its corresponding relaxation dynamics depend on the lane- changing probability pch. Moreover, the relaxation time T diverges as the form of a power-law.

  8. Lane-Level Road Information Mining from Vehicle GPS Trajectories Based on Naïve Bayesian Classification

    Luliang Tang

    2015-11-01

    Full Text Available In this paper, we propose a novel approach for mining lane-level road network information from low-precision vehicle GPS trajectories (MLIT, which includes the number and turn rules of traffic lanes based on naïve Bayesian classification. First, the proposed method (MLIT uses an adaptive density optimization method to remove outliers from the raw GPS trajectories based on their space-time distribution and density clustering. Second, MLIT acquires the number of lanes in two steps. The first step establishes a naïve Bayesian classifier according to the trace features of the road plane and road profiles and the real number of lanes, as found in the training samples. The second step confirms the number of lanes using test samples in reference to the naïve Bayesian classifier using the known trace features of test sample. Third, MLIT infers the turn rules of each lane through tracking GPS trajectories. Experiments were conducted using the GPS trajectories of taxis in Wuhan, China. Compared with human-interpreted results, the automatically generated lane-level road network information was demonstrated to be of higher quality in terms of displaying detailed road networks with the number of lanes and turn rules of each lane.

  9. Methodology for assessing emission reduction of truck-only toll lanes

    The emissions of carbon dioxide (CO2), the largest component of greenhouse gases (GHG) emissions, emitted from heavy trucks is second only to passenger cars in terms of GHG emissions from the transportation sector. Truck-only toll (TOT) lanes have been proposed in several cities as a means of improving truck flows and reducing freeway congestion. This paper describes an analysis that utilized the US EPA's MOBILE6.2 vehicle emissions modeling software to identify freeway locations with large pollutant emissions and estimated the changes in emission associated with TOT lanes. Emissions including hydrocarbon (HC), carbon monoxide (CO), nitrogen oxide (NOx), and CO2 were estimated by multiplying vehicle kilometers traveled by emission factors associated with various vehicle types and average speeds. The CO2 calculation was limited due to lack of sensitivity in the model of speed variation, which is one of the benefits of the implementation of TOT lanes. Mechanical equations of engine horsepower involving the change in vehicle speeds is applied to estimate the change in CO2 fuel consumption and then converted to estimate the change in CO2 emissions. The results show that voluntary and mandatory use of TOT lanes would reduce total CO2 emissions on all freeway lanes by 62% and 60%.

  10. Sensor fusion: lane marking detection and autonomous intelligent cruise control system

    Baret, Marc; Baillarin, S.; Calesse, C.; Martin, Lionel

    1995-12-01

    In the past few years MATRA and RENAULT have developed an Autonomous Intelligent Cruise Control (AICC) system based on a LIDAR sensor. This sensor incorporating a charge coupled device was designed to acquire pulsed laser diode emission reflected by standard car reflectors. The absence of moving mechanical parts, the large field of view, the high measurement rate and the very good accuracy for distance range and angular position of targets make this sensor very interesting. It provides the equipped car with the distance and the relative speed of other vehicles enabling the safety distance to be controlled by acting on the throttle and the automatic gear box. Experiments in various real traffic situations have shown the limitations of this kind of system especially on bends. All AICC sensors are unable to distinguish between a bend and a change of lane. This is easily understood if we consider a road without lane markings. This fact has led MATRA to improve its AICC system by providing the lane marking information. Also in the scope of the EUREKA PROMETHEUS project, MATRA and RENAULT have developed a lane keeping system in order to warn of the drivers lack of vigilance. Thus, MATRA have spread this system to far field lane marking detection and have coupled it with the AICC system. Experiments will be carried out on roads to estimate the gain in performance and comfort due to this fusion.

  11. Studies of vehicle lane-changing to avoid pedestrians with cellular automata

    Li, Xiang; Sun, Jian-Qiao

    2015-11-01

    This paper presents studies of interactions between vehicles and crossing pedestrians. A cellular automata system model of the traffic is developed, which includes a number of subsystem models such as the single-lane vehicle model, pedestrian model, interaction model and lane-changing model. The random street crossings of pedestrians are modeled as a Poisson process. The drivers of the passing vehicles are assumed to follow a safety-rule in order not to hit the pedestrians. The results of both single and multiple car simulations are presented. We have found that in general, the traffic can benefit from vehicle lane-changing to avoid road-crossing pedestrians. The traffic flow and average vehicle speed can be increased, which leads to higher traffic efficiency. The interactions between vehicles and pedestrians are reduced, which results in shorter vehicle decelerating time due to pedestrians and less switches of the driving mode, thus leads to the better energy economy. The traffic safety can be improved in the perspective of both vehicles and pedestrians. Finally, pedestrians can cross road faster. The negative effect of lane-changing is that pedestrians have to stay longer between the lanes in the crossing.

  12. Heterogeneous Traffic Flow Model for a Two-Lane Roundabout and Controlled Intersection

    Feng, Y.; Liu, Y.; Deo, P.; Ruskin, H. J.

    Modern urban traffic management depends heavily on the efficiency of road features, such as controlled intersections and multi-lane roundabouts. Vehicle throughput at any such configuration is modified by traffic mix, by rules governing manoeuvrability and by driver observance, as well as by traffic density. Here, we study heterogeneous traffic flow on two-lane roads through a cellular automata model for a binary mix of long and short vehicles. Throughput is investigated for a range of arrival rates and for fixed turning rate at an intersection: manoeuvres, while described in terms of left-lane driving, are completely generalisable. For a given heterogeneous distribution of vehicle type, there is a significant impact on queue length, delay times experienced and throughput at a fixed-cycle traffic light controlled two-way intersection and two-lane roundabout, when compared to the homogeneous case. As the proportion of long vehicles increases, average throughput for both configurations declines for increasing arrival rate, with average queue length and waiting time correspondingly increased. The effect is less-marked for the two-lane roundabout, due to absence of cross-traffic delays. Nevertheless, average waiting times and queue lengths remain uniformly high for arrival rates >0.25 vehicle per second (900 vph) on entry roads and for long vehicle proportion above 0.30-0.35.

  13. Effect of Driver Scope Awareness in the Lane Changing Maneuvers Using Cellular Automaton Model

    Kohei Arai

    2013-07-01

    Full Text Available This paper investigated the effect of drivers’ visibility and their perception (e.g., to estimate the speed and arrival time of another vehicle on the lane changing maneuver. The term of scope awareness was used to describe the visibility required by the driver to make a perception about road condition and the speed of vehicle that exist in that road. A computer simulation model was conducted to show this driver awareness behavior. This studying attempt to precisely catching the lane changing behavior and illustrate the scope awareness parameter that reflects driver behavior. This paper proposes a simple cellular automata model for studying driver visibility effects of lane changing maneuver and driver perception of estimated speed. Different values of scope awareness were examined to capture its effect on the traffic flow. Simulation results show the ability of this model to capture the important features of lane changing maneuver and revealed the appearance of the short-thin solid line jam and the wide solid line jam in the traffic flow as the consequences of lane changing maneuver.

  14. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    George Hess

    Full Text Available Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  15. Unidirectional laning and migrating cluster crystals in confined self-propelled particle systems

    One standard approach to describe the collective behaviour of self-propelled particles is the Vicsek model: point-like self-propelled particles tend to align their migration directions to the ones of their nearer neighbours at each time-step. Here we use a variant of the Vicsek model that includes pairwise repulsive interactions. Confining the system between parallel walls can qualitatively change its appearance: a laning state can emerge that is different from the ones previously reported. All lanes show on average the same migration direction of the contained particles with a finite separation distance between the lanes. Furthermore, in certain parameter ranges we observe collectively migrating clusters that arrange in an approximately hexagonal way. We suggest that the mechanism behind these regular textures is an overreaction in the alignment mechanism. Considering the more realistic scenario of non-point-like particles in the presence of confining surfaces is generally important for the comparison to experimental systems. (paper)

  16. An Abstract Model for Proving Safety of Multi-lane Traffic Manoeuvres

    Hilscher, Martin; Linker, Sven; Olderog, Ernst-Rüdiger;

    2011-01-01

    We present an approach to prove safety (collision freedom) of multi-lane motorway traffic with lane-change manoeuvres. This is ultimately a hybrid verification problem due to the continuous dynamics of the cars. We abstract from the dynamics by introducing a new spatial interval logic based on the...... view of each car. To guarantee safety, we present two variants of a lane-change controller, one with perfect knowledge of the safety envelopes of neighbouring cars and one which takes only the size of the neighbouring cars into account. Based on these controllers we provide a local safety proof for...... unboundedly many cars by showing that at any moment the reserved space of each car is disjoint from the reserved space of any other car....

  17. Traffic of single-headed motor proteins KIF1A: effects of lane changing

    Chowdhury, Debashish

    2007-01-01

    Kinesins are biomolecular motors which move on cylindrical nano-tubes called microtubules. A normal microtubule consists of more than one protofilament on which the equispaced motor binding sites form a periodic array. The collective movement of the kinesins on a microtubule is, therefore, analogous to vehicular traffic on multi-lane highways where each protofilament is the analogue of a single lane. We extend a recent model of the traffic of single-headed kinesin KIF1A [{\\it Phys. Rev. E {\\bf 75}, 041905 (2007)}] by incorporating processes which correspond to shifting of the motor proteins from one protofilament to another. On the basis of analytical treatment of our model, we predict the effects of lane changing on the flux of the KIF1A motors. Our quantitative predictions can be tested, in principle, by carrying out {\\it in-vitro} experiments with fluorescently labelled KIF1A molecules.

  18. Stability classification model of mine-lane surrounding rock based on distance discriminant analysis method

    ZHANG Wei; LI Xi-bing; GONG Feng-qiang

    2008-01-01

    Based on the principle of Mahalanobis distance discriminant analysis (DDA) theory, a stability classification model for mine-lane surrounding rock was established, including six indexes of discriminant factors that reflect the engineering quality of surrounding rock: lane depth below surface, span of lane, ratio of directly top layer thickness to coal thickness, uniaxial comprehensive strength of surrounding rock, development degree coefficient of surrounding rock joint and range of broken surrounding rock zone. A DDA model was obtained through training 15 practical measuring samples. The re-substitution method was introduced to verify the stability of DDA model and the ratio of mis-discrimination is zero. The DDA model was used to discriminate3 new samples and the results are identical with actual rock kind. Compared with the artificial neural network method and support vector mechanic method, the results show that this model has high prediction accuracy and can be used in practical engineering.

  19. Analysis on Traffic Conflicts of Two-lane Highway Based on Improved Cellular Automation Model

    Xiru Tang

    2013-06-01

    Full Text Available Based on microscopic traffic characteristics of two-lane highway and different driving characteristics for drivers, the characteristics of drivers and vehicle structure are introduced into Cellular Automation model for establishing new Cellular Automation model of two-lane highway. Through computer simulation, the paper analyzes the effect of the promotion of different vehicles, drivers and arrival rates on traffic conflicts of two-lane highway, which gets the relationship between the parameters such as road traffic and velocity variance and collision. The results indicate that the frequency of traffic conflicts has close relationship with the product of traffic flow and velocity variation. When the traffic flow and velocity variation are great, the frequency of the conflict is the greatest, and when the traffic flow and velocity variation are little, the frequency of the conflict is the least.

  20. Flow of autonomous traffic on a single multi-lane street

    Polito, Federico

    2007-01-01

    We investigate the behaviour of an original traffic model. The model considers a single multi-lane street, populated by autonomous vehicles directed from either end to the other. Lanes have no intrinsic directionality, and the vehicles are inserted at random at either end and any lane. Collision avoidance is fully automatic and, to enhance the transport capacity of the street, vehicles form_trains_ in which they may travel at high speed quite close to the vehicle in front. We report on the transit times for vehicles under a wide variety of conditions: vehicle insertion probability & imbalance and their maximum speed distribution. We also outline an interesting feature of the model, that the complex interactions of many vehicles are considerably more powerful than a simple "keep left" directive which each vehicle should obey.

  1. Lane formation in pedestrian counterflows driven by a potential field considering following and avoidance behaviours

    Guo, Wei; Wang, Xiaolu; Zheng, Xiaoping

    2015-08-01

    Lane formation in pedestrian counterflows is an interesting self-organization phenomenon. It is believed to be caused by the following or avoidance behaviours of pedestrians. In this paper, a potential field CA model that considers the velocity and density distributions of a crowd and their subjective consciousness is proposed to study the effects of the two behaviours on lane formation in the case of a pedestrian counterflow in a corridor with a periodic boundary. An indexing system is introduced to distinguish the three different patterns observed in the counterflow, and a smoothness index is introduced to measure the smoothness of the counterflow. It is found that avoidance behaviour is more relevant to lane formation than following behaviour. Some differences between the two behaviours are also presented.

  2. Careers in Auto Racing: Work in the Fast Lane

    Lawhorn, William

    2009-01-01

    Long before most people had seen an automobile, thrill-seekers across the globe were driving cars competitively. The speed of racecars has accelerated steadily, as has the popularity of the sport. In public opinion polls of sports popularity, in fact, auto racing consistently finishes near the top. Racecar drivers may be the star of their event,…

  3. Can Accelerators Accelerate Learning?

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  4. Economic Analysis of Bus-Lane Application: A Case Study in Millet Street

    Çorum, Adnan; Akbıyık, Emre; Demir, Göksel

    2015-01-01

    The traffic problem which gets worse with the increasing population and mobility in Istanbul, one of the biggest metropolises of the world, has been an attractive subject for the transportation experts. It is obvious that Bus-lane, which is one of the oldest methods to solve traffic jam and promote public transportation, brings advantages. In this study it is aimed to measure, quantify, and analyze the benefit of the Bus-lane application. The study contains 25 lines and their data that are se...

  5. Approximate Solution to the Fractional Second Type Lane-Emden Equation

    Abdel-Salam, E A

    2015-01-01

    The spherical isothermal Lane-Emden equation is a second order non-linear differential equation that model many configurations in astrophysics. In the present paper and based on the fractal index technique and the series expansion, the fractional lane-Emden equation involving modified Riemann-Liouville derivative is solved. The results indicate that, the series converges for the radius range with fractional parameter spreads over a wide range of the fractional parameter . Comparison with the numerical solution revealed a good agreement with a maximum relative error 0.05.

  6. Spontaneous-braking and lane-changing effect on traffic congestion using cellular automata model applied to the two-lane traffic

    Kohei Arai

    2012-08-01

    Full Text Available In the real traffic situations, vehicle would make a braking as the response to avoid collision with another vehicle or avoid some obstacle like potholes, snow, or pedestrian that crosses the road unexpectedly. However, in some cases the spontaneous-braking may occur even though there are no obstacles in front of the vehicle. In some country, the reckless driving behaviors such as sudden-stop by public-buses, motorcycle which changing lane too quickly, or tailgating make the probability of braking getting increase. The new aspect of this paper is the simulation of braking behavior of the driver and presents the new Cellular Automata model for describing this characteristic. Moreover, this paper also examines the impact of lane-changing maneuvers to reduce the number of traffic congestion that caused by spontaneous-braking behavior of the vehicles.

  7. Sílvia Lane e o projeto do "Compromisso Social da Psicologia" SÍlvia Lane and the project for a socially committed psychology

    Ana Mercês Bahia Bock; Marcos Ribeiro Ferreira; Maria da Graça M. Gonçalves; Odair Furtado

    2007-01-01

    Este artigo apresenta os principais aspectos da trajetória da Profa. Sílvia Tatiana Maurer Lane, desde a construção de uma Psicologia Social crítica até a formulação de um projeto de compromisso social da Psicologia. A Profa. Sílvia Lane foi pioneira nas formulações teóricas que colocaram a Psicologia Social brasileira em questão, ressaltando a necessidade de se explicitar seu vínculo com interesses dominantes e de se redirecionar sua produção no sentido de contribuir para a transformação soc...

  8. 78 FR 51184 - Air Pollution Control: Proposed Actions on Clean Air Act Section 105 Grant to the Lane Regional...

    2013-08-20

    ... AGENCY Air Pollution Control: Proposed Actions on Clean Air Act Section 105 Grant to the Lane Regional... Lane Regional Air Protection Agency (LRAPA) in Eugene, Oregon is a result of agency wide non-selective...-selective reduction on September 30, 2011. In consideration of legislative history, the guidance...

  9. Plasma accelerators

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  10. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.

  11. Lane Departure System Design using with IR Camera for Night-time Road Conditions

    Osman Onur Akırmak

    2015-02-01

    Full Text Available Today, one of the largest areas of research and development in the automobile industry is road safety. Many deaths and injuries occur every year on public roads from accidents caused by sleepy drivers, that technology could have been used to prevent. Lane detection at night-time is an important issue in driving assistance systems. This paper deals with vision-based lane detection and tracking at night-time. This project consists of a research and development of an algorithm for automotive systems to detect the departure of vehicle from out of lane. Once the situation is detected, a warning is issued to the driver with sound and visual message through “Head Up Display” (HUD system. The lane departure is detected through the images obtained from a single IR camera, which identifies the departure at a satisfactory accuracy via improved quality of video stream. Our experimental results and accuracy evaluation show that our algorithm has good precision and our detecting method is suitable for night-time road conditions.

  12. 112-Gbit/s × 4-lane duobinary-4-PAM for 400GBase

    Suhr, Lau Frejstrup; Vegas Olmos, Juan José; Mao, B.;

    2014-01-01

    Novel duobinary-4-PAM signaling is experimentally demonstrated to support a 4-lane low-latency 400GbE client side solution. Direct detection of 112 Gbps transmission over a 5 km single wavelength and polarization fiber link is achieved....

  13. A parallel code for multiprecision computations of the Lane-Emden differential equation

    Geroyannis, Vassilis S

    2016-01-01

    We compute multiprecision solutions of the Lane-Emden equation. This differential equation arises when introducing the well-known polytropic model into the equation of hydrostatic equilibrium for a nondistorted star. Since such multiprecision computations are time-consuming, we apply to this problem parallel programming techniques and thus the execution time of the computations is drastically reduced.

  14. Approximate Analytic and Numerical Solutions to Lane-Emden Equation via Fuzzy Modeling Method

    De-Gang Wang

    2012-01-01

    Full Text Available A novel algorithm, called variable weight fuzzy marginal linearization (VWFML method, is proposed. This method can supply approximate analytic and numerical solutions to Lane-Emden equations. And it is easy to be implemented and extended for solving other nonlinear differential equations. Numerical examples are included to demonstrate the validity and applicability of the developed technique.

  15. The global economic cycle and satellite-derived NO2 trends over shipping lanes

    Ruyter de Wildt, Martijn; Eskes, Henk; Boersma, K. Folkert

    2012-01-01

    In recent years, space-borne spectrometers have been used to detect shipping emissions of nitrogen oxides. Driven by economic growth, these emissions have been increasing for several decades, yet in few studies it has been attempted to detect trends in ship emitted NO2 from space. Here a method is presented that enhances the shipping signal in satellite measurements of NO2, which makes it possible to detect non-linear trends on a monthly to yearly basis. The method removes variations in NO2measurements over shipping lanes that are not related to shipping and that obscure shipping trends. With this method we could detect non-linear trends in NO2over major shipping lanes in the Mediterranean Sea, the Red Sea, the Indian Ocean and the South Chinese Sea. The shipping signal displays a large increase of 62-109% between 2003 and the summer of 2008 and a sharp decline of 12-36% afterwards, corresponding to the global economic recession of 2008-2009. These two trends are detected over all four shipping lanes by several space-borne spectrometers. Because of high correlations between satellite data mutually and between satellite data, shipping statistics and international trade volumes, we conclude that the detected trends are caused by actual changes in shipping emissions. This study therefore shows that it is possible to detect short-term economic fluctuations in satellite measurements of NO2 over major shipping lanes.

  16. CityMobil : Human factor issues regarding highly automated vehicles on eLane

    Toffetti, A.; Wilschut, E.S.; Martens, M.H.; Schieben, A.; Rambaldini, A.; Merat, N.; Flemisch, F.

    2009-01-01

    There are several human factor concerns with highly autonomous or semiautonomous driving, such as transition of control, loss of skill, and dealing with automated system errors. Four CityMobil experiments studied the eLane concept for dual-mode cars, and the results of one are described. The open eL

  17. 75 FR 22578 - Application To Export Electric Energy; Centre Lane Trading Limited

    2010-04-29

    ... Application To Export Electric Energy; Centre Lane Trading Limited AGENCY: Office of Electricity Delivery and... applied for authority to transmit electric energy from the United States to Canada pursuant to section 202... application from CLT for authority to transmit electric energy from the United States to Canada as a...

  18. An Optimization Model for the Selection of Bus-Only Lanes in a City.

    Chen, Qun

    2015-01-01

    The planning of urban bus-only lane networks is an important measure to improve bus service and bus priority. To determine the effective arrangement of bus-only lanes, a bi-level programming model for urban bus lane layout is developed in this study that considers accessibility and budget constraints. The goal of the upper-level model is to minimize the total travel time, and the lower-level model is a capacity-constrained traffic assignment model that describes the passenger flow assignment on bus lines, in which the priority sequence of the transfer times is reflected in the passengers' route-choice behaviors. Using the proposed bi-level programming model, optimal bus lines are selected from a set of candidate bus lines; thus, the corresponding bus lane network on which the selected bus lines run is determined. The solution method using a genetic algorithm in the bi-level programming model is developed, and two numerical examples are investigated to demonstrate the efficacy of the proposed model. PMID:26214001

  19. We Have Met Our Past and Our Future: Thanks for the Walk down Memory Lane

    Wiseman, Robert C.

    2006-01-01

    In this article, the author takes the readers for a walk down memory lane on the use of teaching aids. He shares his experience of the good old days of Audio Visual--opaque projector, motion pictures/films, recorders, and overhead projector. Computers have arrived, and now people can make graphics, pictures, motion pictures, and many different…

  20. Inner-Outer Lane Advantage in Olympic 1000 Meter Speed Skating

    Kamst, Richard; Kuper, Gerard H.; Sierksma, Gerard; Talsma, Bertus G.

    2012-01-01

    During the Olympic Games and the World Championships Single Distances the 1000m is skated by every skater only one time. However, there may be a difference in skating a 1000m race with a start in the inner and the outer lane that introduces an externality that introduces unfairness. We show that thi

  1. "Go West, Young Man!" - Praktikum an der Lane Medical Library der Universität Stanford

    Dollfuß, Helmut

    2006-12-01

    Full Text Available This is an account of a five weeks internship at Lane Medical Library which is part of Stanford University, California. The story depicts personal impressions and reports on the university, on the library's history, organisation and its future development.

  2. No reserved communication lanes for high energy (Italian original version

    Nico Pitrelli

    2006-06-01

    Full Text Available The American particle physics community is in jeopardy and may end up drowning in a boundless sea trying to grasp at non-existing funds, dragging US physics and science as a whole to the bottom. This is a price the most powerful and high-tech country of the world cannot afford, as warned by the editors of a report published in late April by the National Academy of Sciences1. Behind so much alarm is the International Linear Collider (ILC – a large particle accelerator facility which, according to the report, should be built on American territory, if research on the elementary constituents of nature is to survive in the United States. The ILC will probably cost a total of five hundred million dollars in the first five years, whereas billions will have to be invested in the subsequent seven years. Hardly impressive, however, if compared with the Superconducting Super Collider (SSC, the biggest and costliest machine ever conceived in the history of science. Devised to describe the first instants of the universe, as many will recall, the SSC project was severely hampered by political and bureaucratic plots in 1993, when the Clinton administration decided to halt work on the accelerator, after ten years and approximately two billion dollars already spent.

  3. Modeling mechanical restriction differences between car and heavy truck in two-lane cellular automata traffic flow model

    Li, Xin; Li, Xingang; Xiao, Yao; Jia, Bin

    2016-06-01

    Real traffic is heterogeneous with car and truck. Due to mechanical restrictions, the car and the truck have different limited deceleration capabilities, which are important factors in safety driving. This paper extends the single lane safety driving (SD) model with limited deceleration capability to two-lane SD model, in which car-truck heterogeneous traffic is considered. A car has a larger limited deceleration capability while a heavy truck has a smaller limited deceleration capability as a result of loaded goods. Then the safety driving conditions are different as the types of the following and the leading vehicles vary. In order to eliminate the well-known plug in heterogeneous two-lane traffic, it is assumed that heavy truck has active deceleration behavior when the heavy truck perceives the forming plug. The lane-changing decisions are also determined by the safety driving conditions. The fundamental diagram, spatiotemporal diagram, and lane-changing frequency were investigated to show the effect of mechanical restriction on heterogeneous traffic flow. It was shown that there would be still three traffic phases in heterogeneous traffic condition; the active deceleration of the heavy truck could well eliminate the plug; the lane-changing frequency was low in synchronized flow; the flow and velocity would decrease as the proportion of heavy truck grows or the limited deceleration capability of heavy truck drops; and the flow could be improved with lane control measures.

  4. Analysis of the wave properties of a new two-lane continuum model with the coupling effect

    Arvind Kumar Gupta; Sapna Sharma

    2012-01-01

    A multilane extension of the single-lane anisotropic continuum model (GK model) developed by Gupta and Katiyar for traffic flow is discussed with the consideration of the coupling effect between the vehicles of different lanes in the instantaneous traffic situation and the lane-changing effect. The conditions for securing the linear stability of the new model are presented.The shock and the rarefaction waves,the local cluster effect and the phase transition are investigated through simulation experiments with the new model and are found to be consistent with the diverse nonlinear dynamical phenomena observed in a real traffic flow.The analysis also focuses on empirically observed twolane phenomena,such as lane usage inversion and the density dependence of the number of lane changes.It is shown that single-lane dynamics can be extended to multilane cases without changing the basic properties of the single-lane model.The results show that the new multilane model is capable of explaining some particular traffic phenomena and is in accordance with real traffic flow.

  5. Efficiency determination of the method "special lane in the intersection area" from the standpoint of priority in time

    Вікович, Ігор Андрійович; Зубачик, Роман Михайлович; Беспалов, Дмитро Олександрович

    2014-01-01

    Using the space-time priority and priority in time at the isolated signal-controlled intersection with one traffic lane on all approaches is considered in the paper. Space-time priority is represented by the method “special lane in the intersection area”, which in this case is a combination of a special lane in the intersection area and adaptive algorithm for a special phase call. Priority in time is realized using the algorithm for continuation of the enable signal and early termination of t...

  6. GPS constraints on shear accommodation in the northern Walker Lane, western Nevada, USA

    Bormann, J. M.; Hammond, W. C.; Kreemer, C. W.; Blewitt, G.; Wesnousky, S. G.

    2009-12-01

    The Walker Lane is a zone of active intracontinental transtension that accommodates approximately 10 mm/yr of right-lateral deformation, up to 20-25% of Pacific-North America relative plate motion. Between Walker Lake and Lake Tahoe, the Walker Lane lacks optimally oriented strike-slip faults to accommodate northwest-directed dextral shear. In this region Quaternary deformation appears to be concentrated in a northwest-trending series of north-striking, normal fault-bounded basins. To address the question of how shear is transferred through this portion of the Walker Lane, we combine GPS data from the University of Nevada, Reno’s semi-continuous MAGNET GPS network with observations from EarthScope’s Plate Boundary Observatory to present a new velocity field for the Walker Lane with an average station spacing of 20 km. Measurements in MAGNET (http://geodesy.unr.edu/networks) began in January 2004 and now provide time series of up to 6 years for the longest running sites and >3 years for all sites. Together with recent improvements in GPS data processing models using the GIPSY-OASIS II software, this allows us to estimate rates with uncertainty well below 1 mm/yr. These recent improvements include the use of reprocessed GPS orbits from the IGS Analysis Center at JPL. Our GPS processing now includes satellite and station antenna calibrations, random-walk tropospheric zenith delay and gradients using the GMF mapping function, second-order ionospheric corrections, global-scale ambiguity resolution using our custom Ambizap software, and our custom Great Basin spatially-filtered reference frame. The velocity solution shows a smooth and continuous increase in shear across the Walker Lane in addition to NW-SE directed extension. We use a block model driven by GPS velocities to estimate the role that vertical axis rotation of fault-bounded blocks and slip on basin-bounding faults play in shear accommodation. The block model also allows us to incorporate published

  7. Future accelerators (?)

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made

  8. Future accelerators (?)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  9. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...

  10. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    Davis, L C

    2015-01-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested stat...

  11. An Optimal Deployment of Wireless Charging Lane for Electric Vehicles on Highway Corridors

    Huang, Yongxi [Clemson University

    2016-01-01

    We propose an integrated modeling framework to optimally locate wireless charging facilities along a highway corridor to provide sufficient in-motion charging. The integrated model consists of a master, Infrastructure Planning Model that determines best locations with integrated two sub-models that explicitly capture energy consumption and charging and the interactions between electric vehicle and wireless charging technologies, geometrics of highway corridors, speed, and auxiliary system. The model is implemented in an illustrative case study of a highway corridor of Interstate 5 in Oregon. We found that the cost of establishing the charging lane is sensitive and increases with the speed to achieve. Through sensitivity analyses, we gain better understanding on the extent of impacts of geometric characteristics of highways and battery capacity on the charging lane design.

  12. Simulation of three lanes one-way freeway in low visibility weather by possible traffic accidents

    Pang, Ming-bao; Zheng, Sha-sha; Cai, Zhang-hui

    2015-09-01

    The aim of this work is to investigate the traffic impact of low visibility weather on a freeway including the fraction of real vehicle rear-end accidents and road traffic capacity. Based on symmetric two-lane Nagel-Schreckenberg (STNS) model, a cellular automaton model of three-lane freeway mainline with the real occurrence of rear-end accidents in low visibility weather, which considers delayed reaction time and deceleration restriction, was established with access to real-time traffic information of intelligent transportation system (ITS). The characteristics of traffic flow in different visibility weather were discussed via the simulation experiments. The results indicate that incoming flow control (decreasing upstream traffic volume) and inputting variable speed limits (VSL) signal are effective in accident reducing and road actual traffic volume's enhancing. According to different visibility and traffic demand the appropriate control strategies should be adopted in order to not only decrease the probability of vehicle accidents but also avoid congestion.

  13. Association of Celiac Disease With Idiopathic Pulmonary Hemosiderosis; Lane Hamilton Syndrome

    Hikmet Tekin Nacaroglu

    2015-10-01

    Full Text Available Introduction: Idiopathic Pulmonary Hemosiderosis (IPH is a rare cause of alveolar hemorrhage, which is seen primarily in childhood. Celiac disease is defined as a chronic, immune-mediated enteropathy of the small intestine, caused by exposure to dietary gluten in genetically pre-disposed individuals. Association of IPH and celiac disease is known as Lane Hamilton syndrome. There are limited number of case reports of this syndrome in literature. Case Presentation: Although there were no growth and developmental delay and gastrointestinal symptoms like chronic diarrhea, chronic constipation, vomiting, abdominal bloating and pain in the two patients with IPH, they were diagnosed with Lane Hamilton Syndrome. After initiation of gluten-free diet, their IPH symptoms disappeared and hemoglobin levels were observed to return to normal. Conclusions: Even if there were no gastrointestinal symptoms in a patient with IPH, celiac disease should be investigated. These patients may benefit from gluten free diet and IPH symptoms may disappear.

  14. NEW GALERKIN OPERATIONAL MATRICES FOR SOLVING LANE-EMDEN TYPE EQUATIONS

    W.M. Abd-Elhameed

    2016-01-01

    Full Text Available Lane-Emden type equations model many phenomena in mathematical physics and astrophysics, such as thermal explosions. This paper is concerned with intro - ducing third and fourth kind Chebyshev-Galerkin operational matrices in order to solve such problems. The principal idea behind the suggested algorithms is based on converting the linear or nonlinear Lane-Emden problem, through the application of suitable spectral methods, into a system of linear or nonlinear equations in the expansion coefficients, which can be efficiently solved. The main advantage of the proposed algorithm in the linear case is that the resulting linear systems are specially structured, and this of course reduces the computational effort required to solve such systems. As an application, we consider the solar model polytrope with n = 3 to show that the suggested solutions in this paper are in good agreement with the numerical results.

  15. New Galerkin operational matrices for solving Lane-Emden type equations

    Abd-Elhameed, W. M.; Doha, E. H.; Saad, A. S.; Bassuony, M. A.

    2016-04-01

    Lane-Emden type equations model many phenomena in mathematical physics and astrophysics, such as thermal explosions. This paper is concerned with introducing third and fourth kind Chebyshev-Galerkin operational matrices in order to solve such problems. The principal idea behind the suggested algorithms is based on converting the linear or nonlinear Lane-Emden problem, through the application of suitable spectral methods, into a system of linear or nonlinear equations in the expansion coefficients, which can be efficiently solved. The main advantage of the proposed algorithm in the linear case is that the resulting linear systems are specially structured, and this of course reduces the computational effort required to solve such systems. As an application, we consider the solar model polytrope with n=3 to show that the suggested solutions in this paper are in good agreement with the numerical results.

  16. Design and evaluation of steering protection for avoiding collisions during a lane change.

    Itoh, Makoto; Inagaki, Toshiyuki

    2014-01-01

    This paper discusses the design of a driver assistance system for avoiding collisions with vehicles in blind spots. The following three types of support systems are compared: (1) a warning system that provides the driver with an auditory alert, (2) a 'soft' protection system that makes the steering wheel stiffer to tell the driver that a lane-change manoeuvre is not recommended and (3) a 'hard' protection system that cancels the driver's input and controls the tyre angle autonomously to prevent lane departure. The results of an experiment showed that the hard protection system was more effective for collision avoidance than either the warning or the soft protection system. The warning and soft protection systems were almost the same in terms of collision avoidance. The results suggest that the human-centred automation principle, which requires the human to have the final authority over the automation, can be violated depending on the context. PMID:24206200

  17. Approximate Analytical Solution to the Fractional Lane-Emden Equation of the Polytropic Gas Sphere

    Nouh, Mohamed I

    2016-01-01

    Lane-Emden equation could be used to model stellar interiors, star clusters and many configurations in astrophysics. Unfortunately, there is an exact solution only for the polytropic index n=0,1 and 5. In the present paper, a series solution for the fractional lane-Emden equation is presented. The solution is performed in the frame of modified Rienmann liouville derivatives. The results indicate that the series converges for the polytropic index range 0<=n <= 4.99 with fractional parameter \\alpha spreads over all range 0<\\alpha <= 1. Comparison with the numerical solution revealed a good agreement with a maximum relative error 0.001. The obtained results recover the well-known series solutions when \\alpha=1.

  18. Flow difference effect in the two-lane lattice hydrodynamic model

    Wang Tao; Gao Zi-You; Zhao Xiao-Mei; Tian Jun-Fang; Zhang Wen-Yi

    2012-01-01

    By introducing a flow difference effect,a modified lattice two-lane traffic flow model is proposed,which is proved to be capable of improving the stability of traffic flow.Both the linear stability condition and the kink-antikink solution derived from the modified Korteweg-de Vries (mKdV) equation are analyzed.Numerical simulations verify the theoretical analysis.Furthermore,the evolution laws under different disturbances in the metastable region are studied.

  19. Gravitational collapse in dust lanes and the appearance of spiral structure in galaxies

    We consider the possibility that there are two fundamental types of spirals in each spiral galaxy: one results from a spiral density wave, and the other is a stochastic spiral produced by the shear of self-propagating star formation events. It is proposed that there is a physical and causal connection between these two spirals, with the role of intermediary played by the dust lanes, which we assume to be shocked interstellar matter. We show that dust lanes should continuously collapse and fragment into massive cloud complexes by the action of their self-gravitational forces. The origin of the molecular ring at 5--6 kpc from the galactic center seems to be the result of a sharp minimum in the opposition to dust lane collapse by galactic tidal forces at these radii. When the resulting clouds begin to form stars (probably by an independent process), the pressures generated by their own OB associations will push them away from their star clusters and cause them to be shuffled around randomly in the region of the galaxy that lies ahead of the dust lane. Massive star formation may occur in the same clouds on numerous occasions, but they will have a different location each time. This shuffling will not only produce the appearance of a stochastic arm of young, star-forming sites (superposed on the underlying spiral), but it will also give the required stability to the numerical calculations of Gerola and Seiden, when combined with the assumption of a steady state cloud population for the whole galaxy. Numerous observational examples of these processes are cited for our own Galaxy and for other galaxies

  20. Two-way multi-lane traffic model for pedestrians in corridors

    Appert-Rolland, Cécile; Degond, Pierre; Motsch, Sébastien

    2011-01-01

    We extend the Aw-Rascle macroscopic model of car traffic into a two-way multi-lane model of pedestrian traffic. Within this model, we propose a technique for the handling of the congestion constraint, i.e. the fact that the pedestrian density cannot exceed a maximal density corresponding to contact between pedestrians. In a first step, we propose a singularly perturbed pressure relation which models the fact that the pedestrian velocity is considerably reduced, if not blocked, at congestion. ...

  1. Validity of Spontaneous Braking and Lane Changing with Scope of Awareness by Using Measured Traffic Flow

    Kohei Arai; Steven Ray Sentinuwo

    2013-01-01

    This paper presents the validation method and its evaluation of the spontaneous braking and lane changing with scope awareness parameter. By using the real traffic flow data, the traffic cellular automaton model that accommodate these two driver behaviors, e.g., spontaneous braking and driver scope awareness has been compared and evaluated. The real traffic flow data have been observed via video-recording captured from real traffic situation. The validation results shown that by accommodate s...

  2. Motion Planning of Autonomous Vehicles on a Dual Carriageway without Speed Lanes

    Rahul Kala; Kevin Warwick

    2015-01-01

    The problem of motion planning of an autonomous vehicle amidst other vehicles on a straight road is considered. Traffic in a number of countries is unorganized, where the vehicles do not move within predefined speed lanes. In this paper, we formulate a mechanism wherein an autonomous vehicle may travel on the “wrong” side in order to overtake a vehicle. Challenges include assessing a possible overtaking opportunity, cooperating with other vehicles, partial driving on the “wrong” side of the r...

  3. A Macroscopic Approach to the Lane Formation Phenomenon in Pedestrian Counterflow

    XIONG Tao; ZHANG Peng; WONG S. C.; SHU Chi-Wang; ZHANG Meng-Ping

    2011-01-01

    We simulate pedestrian counterflow by adopting an optimal path-choice strategy and a recently observed speed-density relationship. Although the whole system is symmetric, the simulation demonstrates the segregation and formation of many walking lanes for two groups of pedestrians. The symmetry breaking is most likely triggered by a small numerical viscosity or "noise", and the segregation is associated with the minimization of travel time. The underlying physics can be compared with the "optimal self-organization" mechanism in Helbing's social force model, by which driven entities in an open system tend to minimize their interaction to enable them to reach some ordering state.%We simulate pedestrian counterflow by adopting an optimal path-choice strategy and a recently observed speeddensity relationship.Although the whole system is symmetric,the simulation demonstrates the segregation and formation of many walking lanes for two groups of pedestrians.The symmetry breaking is most likely triggered by a small numerical viscosity or “noise”,and the segregation is associated with the minimization of travel time.The underlying physics can be compared with the “optimal self-organization” mechanism in Helbing's social force model,by which driven entities in an open system tend to minimize their interaction to enable them to reach some ordering state.The phenomenon of lane formation in pedestrian flows has been frequently observed through direct observation or controlled experiments.Helbing et al.[4]presented photographs to show that pedestrians could form uniform walking lanes at sufficiently high densities.Theoretically,the phenomenon was explained through an optimal self-organization mechanism,[3,6]namely,a pedestrian crowd constitutes an open system of driven entities that tends to minimize interaction and dissipation,and thus an optimal state is reached.This differs from a closed system,which is governed by the second law of thermodynamics and thus the entropy

  4. Integrated Driver and Active Steering Control for Vision-Based Lane Keeping

    MARINO, Riccardo; Scalzi, Stefano; Netto, Mariana

    2012-01-01

    A nested PID steering control for autonomous vehicles equipped with artificial vision systems is designed so that the driver can override the automatic lane-keeping action and obtain a complete control of the vehicle lateral dynamics without any switching strategy. The control input is the steering wheel angle: it is designed on the basis of the yaw rate, which is measured by a gyroscope, and the lateral offset, which is measured by the vision system as the distance between the road centerlin...

  5. Integrating Collision Avoidance, Lane Keeping, and Cruise Control With an Optimal Controller and Fuzzy Controller

    Grefe, William Kevin

    2005-01-01

    This thesis presents collision avoidance integrated with lane keeping and adaptive cruise control for a car. Collision avoidance is the ability to avoid obstacles that are in the vehicleâ s path, without causing damage to the obstacle or car. There are three types of collision avoidance controllers, passive, active, and semi-active. This thesis is designed using active collision avoidance controllers. There are two controllers developed for collision avoidance in this paper. They are ...

  6. Spring-block model for a single-lane highway traffic

    Jarai-Szabo, Ferenc; Sandor, Bulcsu; Neda, Zoltan

    2010-01-01

    A simple one-dimensional spring-block chain with asymmetric interactions is considered to model an idealized single-lane highway traffic. The main elements of the system are blocks (modeling cars), springs with unidirectional interactions (modeling distance keeping interactions between neighbors), static and kinetic friction (modeling inertia of drivers and cars) and spatiotemporal disorder in the values of these friction forces (modeling differences in the driving attitudes). The traveling c...

  7. Dynamic Steering Control of Battery Operated Car for Lane Keeping using Image Sensor

    Ankit Sharma; Abhishek Srivastava; Amod Garg

    2011-01-01

    This project presents simple prototype for driving automation of battery operated cars. The system consists of Decision Making Unit (DMU) & Control System Unit (CSU) to implement decision given by DMU. DMU performs the task of image acquisition, enhancing, thresholding, noise reduction, calculation of the position of car with respect to lanes and estimation of the desired position. DMU communicate with CSU using UART serial protocol, thereby informing CSU to take necessary control action rega...

  8. Reassessing international investment patterns: a revisitation of Lane and Milesi-Ferretti's evidence.

    Pierucci, Eleonora; Pericoli, Filippo; VENTURA , Luigi

    2014-01-01

    We show that recent methodological advances in econometric theory raise questions about the results obtained by Lane and Milesi-Ferretti (LMF) in relation to the determinants of international investment patterns (International Investment Patterns, The Review of Economics and Statistics 2008; 90(3): 538{549). We find that LMF's estimated equations are affected by heteroscedasticity (which can lead to inconsistent estimates in log-linearized models), and that the results depend on the pattern o...

  9. Lynches Lane Reed & Willow Bed Facility Final Report South Dubin County Council

    McCarton, Liam; O'Hogain, sean; McDonald, Don; Reid, Anna

    2012-01-01

    This final report will present results from a two year study to monitor the performance of a hybrid reed willow bed facility at Lynches Lane, in the administrative area of South Dublin County Council (SDCC). Design specifications for the facility are presented. Monitoring results for a two year period including influent and effluent parameters, rainfall, potential evapotranspiration, and soil classification are also presented and discussed. During the two year monitoring period the system ach...

  10. Fast food purchasing and access to fast food restaurants: a multilevel analysis of VicLANES

    Kavanagh Anne M; Bentley Rebecca J; Thornton Lukar E

    2009-01-01

    Abstract Background While previous research on fast food access and purchasing has not found evidence of an association, these studies have had methodological problems including aggregation error, lack of specificity between the exposures and outcomes, and lack of adjustment for potential confounding. In this paper we attempt to address these methodological problems using data from the Victorian Lifestyle and Neighbourhood Environments Study (VicLANES) – a cross-sectional multilevel study con...

  11. Consistency and sensitivity of lane change test according to driving simulator characteristics

    BRUYAS, Marie-Pierre; BRUSQUE, Corinne; Tattegrain, Hélène; AURIAULT, Adrien; AILLERIE, Isabelle; DURAZ, Max

    2008-01-01

    The aim, here, is to evaluate consistency and sensitivity of the lane change test (LCT), which is the subject of a proposed ISO standard. The method is intended to estimate driver distraction while a secondary task is being performed, by measuring performance degradation on a primary driving-like task. An experiment was conducted in two experimental contexts: a fixed-base driving simulator and a personal computer (PC) (including pedals and steering wheel), and with two auditory and two visual...

  12. Hybrid functions for nonlinear initial-value problems with applications to Lane-Emden type equations

    Marzban, H.R.; Tabrizidooz, H.R. [Department of Mathematics, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Razzaghi, M. [Department of Mathematics and Statistics Mississippi State University, Mississippi State, MS 39762 (United States); Department of Applied Mathematics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)], E-mail: razzaghi@math.msstate.edu

    2008-09-08

    A numerical method for solving nonlinear initial-value problems is proposed. The Lane-Emden type equations which have many applications in mathematical physics are then considered. The method is based upon hybrid function approximations. The properties of hybrid of block-pulse functions and Lagrange interpolating polynomials are presented and are utilized to reduce the computation of nonlinear initial-value problems to a system of non-algebraic equations. The method is easy to implement and yields very accurate results.

  13. Association of Celiac Disease With Idiopathic Pulmonary Hemosiderosis; Lane Hamilton Syndrome

    Hikmet Tekin Nacaroglu; Ozlem Sarac Sandal; Ozlem Bag; Semiha Bahceci Erdem; Ozlem Bekem Soylu; Gulden Diniz; Aysel Ozturk; Demet Can

    2015-01-01

    Introduction: Idiopathic Pulmonary Hemosiderosis (IPH) is a rare cause of alveolar hemorrhage, which is seen primarily in childhood. Celiac disease is defined as a chronic, immune-mediated enteropathy of the small intestine, caused by exposure to dietary gluten in genetically pre-disposed individuals. Association of IPH and celiac disease is known as Lane Hamilton syndrome. There are limited number of case reports of this syndrome in literature. ...

  14. ADAS on COTS with OpenCL: A Case Study with Lane Detection

    Kai Huang, Biao Hu, Long Chen, Alois Knoll, Zhihua Wang

    2016-01-01

    The concept of autonomous cars is driving a boost for car electronics and the size of automotive semiconductor market is foreseen to double by 2025. How to benefit from this boost is an interesting question. This article presents a case study to test the feasibility of using OpenCL as the programming language and COTS components as the underlying platforms for ADAS development. For representative ADAS applications, a scalable lane detection is developed that can tune the trade-off be...

  15. Estimating the safety effects of lane widths on urban streets in Nebraska using the propensity scores-potential outcomes framework.

    Wood, Jonathan S; Gooch, Jeffrey P; Donnell, Eric T

    2015-09-01

    A sufficient understanding of the safety impact of lane widths in urban areas is necessary to produce geometric designs that optimize safety performance for all users. The overarching trend found in the research literature is that as lane widths narrow, crash frequency increases. However, this trend is inconsistent and is the result of multiple cross-sectional studies that have issues related to lack of control for potential confounding variables, unobserved heterogeneity or omitted variable bias, or endogeneity among independent variables, among others. Using ten years of mid-block crash data on urban arterials and collectors from four cities in Nebraska, crash modification factors (CMFs) were estimated for various lane widths and crash types. These CMFs were developed using the propensity scores-potential outcomes methodology. This method reduces many of the issues associated with cross-sectional regression models when estimating the safety effects of infrastructure-related design features. Generalized boosting, a non-parametric modeling technique, was used to estimate the propensity scores. Matching was performed using both Nearest Neighbor and Mahalanobis matching techniques. CMF estimation was done using mixed-effects negative binomial or Poisson regression with the matched data. Lane widths included in the analysis included 9ft, 10ft, 11ft, and 12ft. Some of the estimated CMFs were point estimates while others were functions of traffic volume (i.e., the CMF changed depending on the traffic volume). Roadways with 10ft travel lanes were found to experience the highest crash frequency relative to other lane widths. Meanwhile, roads with 9ft travel lanes were found to experience the lowest relative crash frequency. While this may be due to increased driver caution when traveling on narrow lanes, it is possible that unobserved factors influenced this result. CMFs for target crash types (sideswipe same-direction and sideswipe opposite-direction) were consistent

  16. 40 Gb/s Lane Rate NG-PON using Electrical/Optical Duobinary, PAM-4 and Low Complex Equalizations

    Wei, J. L.; Grobe, Klaus; Wagner, Christoph;

    2016-01-01

    We present the first numerical investigation and comparison of 40-Gb/s lane rate electrical Duobinary, optical Duobinary and PAM-4 for NG-PONs incorporating low complex linear and nonlinear post-equalizations.......We present the first numerical investigation and comparison of 40-Gb/s lane rate electrical Duobinary, optical Duobinary and PAM-4 for NG-PONs incorporating low complex linear and nonlinear post-equalizations....

  17. A New Lane Departure Warning Algorithm Considering the Driver’s Behavior Characteristics

    Lun Hui Xu

    2015-01-01

    Full Text Available In order to meet the driving safety warning required for different driver types and situations, a new lane departure warning (LDW algorithm was proposed. Its adaptability is much better through setting the different thresholds of time to lane crossing (TLC using fuzzy control method for driver with different driving behaviors in different lanes and different vehicle movements. To ensure the accuracy of computation of TLC under the different actual driving scenarios, the algorithm was established based on vehicle kinematics and advanced mathematics compared to other ways of computation of TLC. On this basis, a LDW strategy determining driver's intentions was presented by introducing identifying vehicle movements. Finally, a vast quantity of the real vehicle experiments was given to demonstrate the effectiveness of the proposed LDW algorithm. The results of the tests show that the algorithm can decrease false alarm rate effectively because of distinguishing from unconscious by real-time vehicle movements, and promote the adaptability to the driver behavior characteristics, so it has favorable driver acceptance and strong intelligence.

  18. Risk appraisal of passing zones on two-lane rural highways and policy applications.

    Mwesige, Godfrey; Farah, Haneen; Koutsopoulos, Haris N

    2016-05-01

    Passing on two-lane rural highways is associated with risks of head-on collision resulting from unsafe completion of passing maneuvers in the opposite traffic lane. In this paper, we explore the use of time-to-collision (TTC) as a surrogate safety measure of the risk associated with passing maneuvers. Logistic regression models to predict the probability to end the passing maneuver with TTC less than 2 or 3s-threshold were developed with the time-gap from initiation of the maneuver to arrival of the opposite vehicle (effective accepted gap), and the passing duration as explanatory variables. The data used for model estimation was collected using stationary tripod-mounted camcorders at 19 passing zones in Uganda. Results showed that passing maneuvers completed with TTC less than 3s are unsafe and often involved sudden speed reduction, flashing headlights, and lateral shift to shoulders. Model sensitivity analysis was conducted for observed passing durations involving passenger cars or short trucks (2-3 axles), and long trucks (4-7 axles) as the passed vehicles for 3s TTC-threshold. Three risk levels were proposed based on the probability to complete passing maneuvers with TTC less than 3s for a range of opposite direction traffic volumes. Applications of the results for safety improvements of two-lane rural highways are also discussed. PMID:26874293

  19. Lane heading difference: An innovative model for drowsy driving detection using retrospective analysis around curves.

    Morris, Drew M; Pilcher, June J; Switzer Iii, Fred S

    2015-07-01

    Driving while sleepy is a serious contributor to automobile accidents. Previous research has shown that drowsy drivers produce systematic errors (variability) in vehicle behavior which are detectable using vehicle monitoring technology. The current study developed a new methodological approach using a vehicle heading difference metric to detect drowsy driving more effectively than other more commonly used methods. Twenty participants completed a driving scenario as well as several measures of fatigue in five testing sessions across a night of sleep deprivation. Each simulated highway driving session lasted 20 min, and was analyzed for lateral lane position variability and vehicle heading difference variability with two statistical methods. Fatigue measures monitored reaction time, attention, and oculomotor movement. The results showed that examining lane heading difference using the absolute value of the raw data detected driving variability better across the night than other statistical models. The results from the fatigue measures indicated an increase in reaction time and response lapses, as well as a decrease in oculomotor reactivity across the night. These results suggest that in fatigued drivers the statistical model using the absolute value of lane heading could be an improved metric for drowsy driving detection that could accurately detect detriments in driving ability at lower levels of fatigue. PMID:25899059

  20. Bidirectional transport and pulsing states in a multi-lane ASEP model

    Lin, Congping; Ashwin, Peter

    2011-01-01

    In this paper, we introduce an ASEP-like transport model for bidirectional motion of particles on a multi-lane lattice. The model is motivated by experiments on organelle motility along a microtubule (MT), where particles are propelled by molecular motors (dynein and kinesin) along the thirteen protofilaments of the MT. In the model, particles can switch directions of motion due to "tug-of-war" events between counteracting motors. Collisions of particles on the same lane can be cleared by switching to adjacent filaments (lane changes). We analyze transport properties of the model with no-flux boundary conditions at the end of a MT ("plus-end" or tip). In particular, we find a nonlinear scaling of the mean number of particles accumulated at the tip ({\\em tip size}) with injection rate and an associated phase transition leading to {\\em pulsing states} characterized by periodic filling and emptying of the system. Moreover, we show that the ability of changing protofilaments can affect the transport efficiency. F...

  1. Multiband imaging observations of a prominent dust lane galaxy NGC 4370

    Patil, M K; Kembhavi, Ajit; Sahu, D K

    2009-01-01

    In this paper we present extinction properties of interstellar dust in a prominent dust lane galaxy NGC 4370 based on the optical broad band (BVRI) imaging observations taken from the Himalaya Chandra Telescope (HCT), Hanle and the near-IR (J,H,K$_s$) images taken from the 2MASS archive. NGC 4370 belongs to the Virgo cluster (VCC 0758) and form a non-interactive pair with NGC 4365 at 10$\\arcmin$. NGC 4370 hosts a prominent dust lane running parallel to its optical major axis and is extended almost up to 1\\arcmin. The extinction curve derived for NGC 4370 is found to run parallel to Galactic extinction curve, implying that the properties of dust in NGC 4370 are identical to those of the canonical grains in the Milky Way. The $R_V$ value is found to be equal to 2.85$\\pm$0.05 and is consitent with the values reported for the dust lane galaxies. The total dust content of NGC 4370 estimated using optical extinction and IRAS flux densities are found to be equal to $4.4\\times 10^4$ \\msol and $2.0\\times 10^5$ \\msol, ...

  2. Robust and Real Time Detection of Curvy Lanes (Curves Having Desired Slopes for Driving Assistance and Autonomous Vehicles

    Amartansh Dubey

    2015-01-01

    Full Text Available One of the biggest reasons for road accidents is cu rvy lanes and blind turns. Even one of the biggest hurdles for new autonomous vehicles is to d etect curvy lanes, multiple lanes and lanes with a lot of discontinuity and noise. This paper p resents very efficient and advanced algorithm for detecting curves having desired slopes (especia lly for detecting curvy lanes in real time and detection of curves (lanes with a lot of noise , discontinuity and disturbances. Overall aim is to develop robust method for this task which is applicable even in adverse conditions. Even in some of most famous and useful libraries like OpenC V and Matlab, there is no function available for detecting curves having desired slope s, shapes, discontinuities. Only few predefined shapes like circle, ellipse, etc, can be detected using presently available functions. Proposed algorithm can not only detect curves with discontinuity, noise, desired slope but also it can perform shadow and illumination correction a nd detect/ differentiate between different curves.

  3. Laser accelerator

    Vigil, Ricardo

    2014-01-01

    Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significan...

  4. An investigation of merging and diverging cars on a multi-lane road using a cellular automation model

    K.Jetto; H.Ez-Zahraouy; A.Benyoussef

    2012-01-01

    In this paper,we have investigated two observed situations in a multi-lane road.The first one concerns a fast merging vehicle.The second situation is related to the case of a fast vehicle leaving the fastest lane back into the slowest lane and targeting a specific way out.We are interested in the relaxation time τ,i.e.,which is the time that the merging (diverging) vehicle spends before reaching the desired lane.Using analytical treatment and numerical simulations for the NaSch model,we have found two states,namely,the free state in which the merging (diverging) vehicle reaches the desired lane,and the trapped state in which τ diverges.We have established phase diagrams for several values of the braking probability.In the second situation,we have shown that diverging from the fast lane targeting a specific way out is not a simple task.Even if the diverging vehicle is in the free phase,two different states can be distinguished.One is the critical state,in which the diverging car can probably reach the desired way out.The other is the safe state,in which the diverging car can surely reach the desired way out.In order to be in the safe state,we have found that the driver of the diverging car must know the critical distance (below which the way out will be out of his reach) in each lane.Furthermore,this critical distance depends on the density of cars,and it follows an exponential law.

  5. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  6. Induction accelerators

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  7. Quantifying the safety effects of horizontal curves on two-way, two-lane rural roads.

    Gooch, Jeffrey P; Gayah, Vikash V; Donnell, Eric T

    2016-07-01

    The objective of this study is to quantify the safety performance of horizontal curves on two-way, two-lane rural roads relative to tangent segments. Past research is limited by small samples sizes, outdated statistical evaluation methods, and unreported standard errors. This study overcomes these drawbacks by using the propensity scores-potential outcomes framework. The impact of adjacent curves on horizontal curve safety is also explored using a cross-sectional regression model of only horizontal curves. The models estimated in the present study used eight years of crash data (2005-2012) obtained from over 10,000 miles of state-owned two-lane rural roads in Pennsylvania. These data included information on roadway geometry (e.g., horizontal curvature, lane width, and shoulder width), traffic volume, roadside hazard rating, and the presence of various low-cost safety countermeasures (e.g., centerline and shoulder rumble strips, curve and intersection warning pavement markings, and aggressive driving pavement dots). Crash prediction is performed by means of mixed effects negative binomial regression using the explanatory variables noted previously, as well as attributes of adjacent horizontal curves. The results indicate that both the presence of a horizontal curve and its degree of curvature must be considered when predicting the frequency of total crashes on horizontal curves. Both are associated with an increase in crash frequency, which is consistent with previous findings in the literature. Mixed effects negative binomial regression models for total crash frequency on horizontal curves indicate that the distance to adjacent curves is not statistically significant. However, the degree of curvature of adjacent curves in close proximity (within 0.75 miles) was found to be statistically significant and negatively correlated with crash frequency on the subject curve. This is logical, as drivers exiting a sharp curve are likely to be driving slower and with more

  8. Phase-plane analysis of the totally asymmetric simple exclusion process with binding kinetics and switching between antiparallel lanes

    Kuan, Hui-Shun

    2016-01-01

    Motor protein motion on biopolymers can be described by models related to the totally asymmetric simple exclusion process (TASEP). Inspired by experiments on the motion of kinesin-4 motors on antiparallel microtubule overlaps, we analyze a model incorporating the TASEP on two antiparallel lanes with binding kinetics and lane switching. We determine the steady-state motor density profiles using phase plane analysis of the steady-state mean field equations and kinetic Monte Carlo simulations. We focus on the the density-density phase plane, where we find an analytic solution to the mean-field model. By studying the phase space flows, we determine the model's fixed points and their changes with parameters. Phases previously identified for the single-lane model occur for low switching rate between lanes. We predict a new multiple coexistence phase due to additional fixed points that appear as the switching rate increases: switching moves motors from the higher-density to the lower-density lane, causing local jamm...

  9. Empirical Study of Accepted Gap and Lane Change Duration within Arterial Traffic under Recurrent and Non-Recurrent Congestion

    Saravanan Gurupackiam

    2012-12-01

    Full Text Available This paper investigated variations in accepted gaps and lane change duration on arterial under recurrent and non-recurrent congestion. Descriptive statistics and best-fit distributions were obtained for the two parameters for both traffic conditions. Hypothesis testing using Mann-Whitney U-Test showed that the means of accepted gaps and lane change durations were statistically different between the two types of traffic’ conditions. The study found that during non-recurrent congestion, drivers on an average accepted smaller gaps but took longer lane change durations. Based on the fact that the data were collected for the same flow-rate (70-90 vehicles/minute in both traffic conditions and based on the literature, the reason for the above findings could be that, drivers get more frustrated during non-recurring congestion that they accept smaller gaps. Drivers visiting the study location for game day (non-recurrent exhibit different driver behavioral characteristics when compared to regular commuters (recurrent which could have also contributed to the statistical differences in the lane changing characteristics of two types of congestion. These findings have direct implications on the lane changing parameters used in microscopic traffic simulation and also help transportation planners and managers to understand driver behavior during recurrent and non-recurrent congestion and better manage the facilities.

  10. Evolution in the Dust Lane Fraction of Edge-on L* Spiral Galaxies since z=0.8

    Holwerda, B W; Radburn-Smith, D; de Jong, R S; Guhathakurta, P; Koekemoer, A; Allen, R J; Böker, T

    2012-01-01

    The presence of a well-defined and narrow dust lane in an edge-on spiral galaxy is the observational signature of a thin and dense molecular disk, in which gravitational collapse has overcome turbulence. Using a sample of galaxies out to z~1 extracted from the COSMOS survey, we identify the fraction of massive disks that display a dust lane. Our goal is to explore the evolution in the stability of the molecular ISM disks in spiral galaxies over a cosmic timescale. We check the reliability of our morphological classifications against changes in restframe wavelength, resolution, and cosmic dimming with (artificially redshifted) images of local galaxies from SDSS. We find that the fraction of L* disks with dust lanes in COSMOS is consistent with the local fraction (~80%) out to z~0.7. At z=0.8, the dust lane fraction is only slightly lower. A somewhat lower dust lane fraction in starbursting galaxies tentatively supports the notion that a high specific star formation rate can efficiently destroy or inhibit a den...

  11. Changes in Central Walker Lane Strain Accommodation near Bridgeport, California; as told by the Stanislaus Group

    Carlson, C. W.; Pluhar, C. J.; Glen, J. M.; Farner, M. J.

    2012-12-01

    Accommodating ~20-25% of the dextral-motion between the Pacific and North American plates the Walker Lane is represented as an elongate, NW oriented, region of active tectonics positioned between the northwesterly-translating Sierra Nevada microplate and the east-west extension of the Basin and Range. This region of transtension is being variably accommodated on regional-scale systems of predominantly strike-slip faulting. At the western edge of the central Walker Lane (ca. 38°-39°N latitude) is a region of crustal-scale blocks bounded by wedge-shaped depositional-basins and normal-fault systems, here defined as the west-central Walker Lane (WCWL). Devoid of obvious strike-slip faulting, the presence of tectonic-block vertical-axis rotations in the WCWL represents unrecognized components of dextral-shearing and/or changes of strain-accommodation over time. We use paleomagnetic reference directions for Eureka Valley Tuff (EVT) members of the late Miocene Stanislaus Group as spatial and temporal markers for documentation of tectonic-block vertical-axis rotations near Bridgeport, CA. Study-site rotations revealed discrete rotational domains of mean vertical-axis rotation ranging from ~10°-30° with heterogeneous regional distribution. Additionally, the highest measured magnitudes of vertical-axis rotation (~50°-60° CW) define a 'Region of High Strain' that includes the wedge-shaped Bridgeport Valley (Basin). This study revealed previously-unrecognized tectonic rotation of reference direction sites from prior studies for two (By-Day and Upper) of the three members of the EVT, resulting in under-estimates of regional strain accommodation by these studies. Mean remanent directions and virtual geomagnetic poles utilized in our study yielded a recalculated reference direction for the By-Day member of: Dec.=353.2°; Inc.= 43.7°; α95=10.1, in agreement with new measurements in the stable Sierra Nevada. This recalculated direction confirmed the presence of previously

  12. Modelling of ambient noise created by a shipping lane to prepare passive inversion: application to Ushant

    Chailloux, C.; Kinda, B.; Bonnel, J.; Gervaise, C.; Stephan, Y.; MARS, J; Hermand, J.-P.

    2011-01-01

    The Ushant thermal front is a seasonal phenomenon which occurs from May to October in a shallow water environment (100m) of the Iroise Sea (off the coast of the north-western France). It corresponds to the boundary separating a well mixed inner shelf water from an open sea stratified water. To determine the dynamic of the front -or more basically the presence of a stratified or homogeneous water column- the possibility to use a shipping lane as a continuous acoustic source is studied. The ori...

  13. Race, gender and class in The inheritance of loss and Brick Lane : a comparative study

    2008-01-01

    This thesis discusses and compares the themes of race, gender and class in Brick Lane by Monica Ali and The Inheritance of Loss by Kiran Desai. My main objective is to explore similarities and differences between the three themes, based on a thorough analysis of characters, settings and plots, and to find out how they correspond and how they differ. The themes of race, gender and class are seen through the lens of migration and multiculturalism in a postcolonial setting, which is a prevailing...

  14. Dibujando un nuevo paradigma: de Golden Lane (1952) a A Journey from A to B (1972)

    Capdevila Castellanos, Iván

    2013-01-01

    Esta tesis tiene como objeto principal evidenciar la relación, aparentemente inexistente, entre el dibujo de Alison y Peter Smithson para la propuesta de concurso de Golden Lane en 1952 y el dibujo de 1972 del grupo italiano Superstudio titulado A Journey from A to B. Serán otros cuatro dibujos principales -Alison y Peter Smithson, Constant Nieuwenhuys, Yona Friedman y Peter Cook- los que servirán para establecer una relación lógica entre los dos citados arriba. En paralelo, la descripción de...

  15. Motion Planning of Autonomous Vehicles on a Dual Carriageway without Speed Lanes

    Rahul Kala

    2015-01-01

    Full Text Available The problem of motion planning of an autonomous vehicle amidst other vehicles on a straight road is considered. Traffic in a number of countries is unorganized, where the vehicles do not move within predefined speed lanes. In this paper, we formulate a mechanism wherein an autonomous vehicle may travel on the “wrong” side in order to overtake a vehicle. Challenges include assessing a possible overtaking opportunity, cooperating with other vehicles, partial driving on the “wrong” side of the road and safely going to and returning from the “wrong” side. The experimental results presented show vehicles cooperating to accomplish overtaking manoeuvres.

  16. Collision Risk for Fixed Offshore Structures Close to High-density Shipping Lanes

    Pedersen, Preben Terndrup

    2002-01-01

    rational risk analysis procedure for fixed offshore structures in shipping lanes with high traffic densities. It deals with the following items: the basic information and the navigational studies needed for a rational collision risk assessment, exemplification of target risk acceptance criteria for the...... structural requirements and the requirements to the navigational arrangements, instead of basing the design on the more traditional prescriptive rules or codes. For the example bridge structure it is shown that fulfilment of the established risk criteria substantially influences the geometric requirements...

  17. 多车道公路的交通通行能力%Traffic Capacity of Multi- lane Highway

    马静宇

    2012-01-01

    According to traffic capacity theory of multi - lane highway, and annual traffic volume forecast result of project vision in Highway Capacity Manual, peak rate and number of lane required by design project are calculat- ed, and number of lane required by construction project is finally determined through calculation of maximum traffic capacity and service level analysis.%根据《道路通行能力手册》中多车道公路通行能力理论及项目远景年交通量预测成果,计算高峰流率、设计工程项目所需车道数;通过最大通行能力计算及服务水平分析,最终确定工程项目的所需车道数。

  18. Traffic paradox on a road segment based on a cellular automaton: Impact of lane-changing behavior

    Feng, Shumin; Li, Jinyang; Ding, Ning; Nie, Cen

    2015-06-01

    The traffic paradox "faster is slower" does not always apply. To study when and where it is valid, a simulation for a real road segment is performed using a novel cellular automaton. This simulation is used to analyze the change in global traffic flow status during free lane-changing behavior under general urban traffic conditions. The impact of lane-changing behavior is quantified into two aspects, time and space, and are described by average delay and transitable flow, respectively. Then surfaces are obtained, which adopt the arriving probability of vehicles and the green ratio as dual independent variables. Thus by the comparison of two surfaces, free lane-changing and straight proceeding, the horizontal projection of the intersecting lines is solved. Finally, the range of occurrence and reasons for the paradox are analyzed.

  19. Ionized gas in E/S0 galaxies with dust lanes

    Finkelman, Ido; J., José G Funes S; Kniazev, Alexei Y; Väisänen, Petri

    2010-01-01

    We report the results of multicolour observations of 30 E/S0 galaxies with dust lanes. For each galaxy we obtained broad-band images and narrow-band images using interference filters isolating the H\\alpha +[NII] emission lines to derive the amount and morphology of dust and ionized gas. To improve the wavelength coverage we retrieved data from the SDSS and 2MASS and combined these with our data. Ionized gas is detected in 25 galaxies and shows in most cases a smooth morphology, although knots and filamentary structure are also observed in some objects. The extended gas distribution closely follows the dust structure, with a clear correlation between the mass of both components. An extinction law by the extragalactic dust in the dark lanes is derived and is used to estimate the dust content of the galaxies. The derived extinction law is used to correct the measured colours for intrinsic dust extinction and the data are fitted with a stellar population synthesis model. We find that the H-alpha emission and colo...

  20. Evaluating the safety risk of roadside features for rural two-lane roads using reliability analysis.

    Jalayer, Mohammad; Zhou, Huaguo

    2016-08-01

    The severity of roadway departure crashes mainly depends on the roadside features, including the sideslope, fixed-object density, offset from fixed objects, and shoulder width. Common engineering countermeasures to improve roadside safety include: cross section improvements, hazard removal or modification, and delineation. It is not always feasible to maintain an object-free and smooth roadside clear zone as recommended in design guidelines. Currently, clear zone width and sideslope are used to determine roadside hazard ratings (RHRs) to quantify the roadside safety of rural two-lane roadways on a seven-point pictorial scale. Since these two variables are continuous and can be treated as random, probabilistic analysis can be applied as an alternative method to address existing uncertainties. Specifically, using reliability analysis, it is possible to quantify roadside safety levels by treating the clear zone width and sideslope as two continuous, rather than discrete, variables. The objective of this manuscript is to present a new approach for defining the reliability index for measuring roadside safety on rural two-lane roads. To evaluate the proposed approach, we gathered five years (2009-2013) of Illinois run-off-road (ROR) crash data and identified the roadside features (i.e., clear zone widths and sideslopes) of 4500 300ft roadway segments. Based on the obtained results, we confirm that reliability indices can serve as indicators to gauge safety levels, such that the greater the reliability index value, the lower the ROR crash rate. PMID:27177395

  1. Learning effects in the lane change task (LCT)--realistic secondary tasks and transfer of learning.

    Petzoldt, Tibor; Brüggemann, Stephanie; Krems, Josef F

    2014-05-01

    Driver distraction is a factor that is heavily involved in traffic crashes. With in-vehicle devices like navigation systems or mobile phones on the rise, the assessment of their potential to distract the driver has become a pressing issue. Several easy-to-use methods have been developed in recent years to allow for such an assessment in the early stages of product development. One of these methods is the lane change task (LCT), a simple driving simulation in which the driver has to change lanes as indicated by different signs along the road. Although the LCT is an ISO sanctioned procedure, there are still open questions. One issue are learning effects which have been found in previous studies and which have the potential to compromise the comparability of test results. In this paper, we present results on two experiments that further explored the effect of previous experience on LCT and secondary task performance. The results confirm that learning effects occur when combining the LCT with a realistic secondary task. Also, we found evidence for the transfer of learning from one secondary task to another to some degree, provided that the two tasks are sufficiently similar. PMID:24070734

  2. A study on single lane-change manoeuvres for determining rearward amplification of multi-trailer articulated heavy vehicles with active trailer steering systems

    Wang, Qiushi; He, Yuping

    2016-01-01

    The Society of Automotive Engineers issued a test procedure, SAE-J2179, to determine the rearward amplification (RA) of multi-trailer articulated heavy vehicles (MTAHVs). Built upon the procedure, the International Organization for Standardization released the test manoeuvres, ISO-14791, for evaluating directional performance of MTAHVs. For the RA measures, ISO-14791 recommends two single lane-change manoeuvres: (1) an open-loop procedure with a single sine-wave steering input; and (2) a closed-loop manoeuvre with a single sine-wave lateral acceleration input. For an articulated vehicle with active trailer steering (ATS), the RA measure in lateral acceleration under the open-loop manoeuvre was not in good agreement with that under the closed-loop manoeuvre. This observation motivates the research on the applicability of the two manoeuvres for the RA measures of MTAHVs with ATS. It is reported that transient response under the open-loop manoeuvre often leads to asymmetric curve of tractor lateral acceleration [Winkler CB, Fancher PS, Bareket Z, Bogard S, Johnson G, Karamihas S, Mink C. Heavy vehicle size and weight - test procedures for minimum safety performance standards. Final technical report, NHTSA, US DOT, contract DTNH22-87-D-17174, University of Michigan Transportation Research Institute, Report No. UMTRI-92-13; 1992]. To explore the effect of the transient response, a multiple cycle sine-wave steering input (MCSSI) manoeuvre is proposed. Simulation demonstrates that the steady-state RA measures of an MTAHV with and without ATS under the MCSSI manoeuvre are in excellent agreement with those under the closed-loop manoeuvre. It is indicated that between the two manoeuvres by ISO-14791, the closed-loop manoeuvre is more applicable for determining the RA measures of MTAHVs with ATS.

  3. Tandem accelerators

    After the installation of Ti-acceleration tubes and substantial modifications and additions to the EN tandem accelerator the performance of the machine has stabilized. The voltage behaviour of the tubes obviously improves as conditioning times necessary to run up to 6 MV decrease. A gridded lens has been added at the entrance of the first acceleration tube, and a second foil stripper is now installed in the short dead section between the high-energy tubes. The MP tandem also has been running stably during most of the year. However, beam instabilities originating from the last tube section and wear problems at the low-energy set of pelletron-chains caused some loss of beam time. During the fall, one set of pelletron charging chains has to be replaced after 49,000 hours of operation. In the course of the year, the MP and the EN tandem accelerators finished their 100,000th and 150,000th hours of operations, respectively. Preparations for the installation of the 3 MV negative heavy ion injector for the MP are progressing steadily. External beam transport, terminal ion optics, and data acquisition and control systems are to a major extent completed; the integration of the terminal power supplies has started. After the final assembly of the accelerator column structure, first voltage runs can be performed. (orig.)

  4. 基于有限零和灰色博弈的车道变换决策分析%Analysis of Lane Change Decision Making Based on the Finite and Zero-sum Grey Game Theory

    彭金栓; 付锐; 郭应时; 袁伟; 王畅

    2011-01-01

    critical conflict point with an acceleration, so as to give the consideration to driving safety and traveling time, then achieve the goal of global optimality. The results may give corresponding theoretical support to the formation mechanism of the traffic conflicts and allocation of right-of-way in a lane change process.

  5. Analysis of eye movements difference between lane keeping and lane changing intention stage%车道保持与换道意图阶段眼动行为差异性分析

    袁伟; 付锐; 吴付威; 彭金栓

    2013-01-01

    In order to solve the problem of low identify rate for identifying lane changing intention relying on turn signal,new identification method for lane changing intention was explored using the difference of 16 driver's eye movement behaviors in different driving tasks.The real-world experiments were conducted to collect driver's eye movements data during lane keeping and lane changing intention stage.Mathematical statistical method was used to analyze eye movement behavior data between different stages,including basic eye movement parameters,attention allocation and visual search patterns.The results show that parameters such as the average fixation time,average saccade amplitude,attention allocation on different lanes,rearview mirror and dashboard attention allocation,fixation transition probabilities between difference fixation areas,horizontal visual search breadths are significantly different between these two stages; during lane changing intention stage,drivers pay more attention on the target lane and rearview mirrors,and pay less attention on the current lane and dashboard,compared with lane keeping stage.Besides,the fixation transition becomes more flexible and the horizontal search breadth becomes more wider during lane changing intention stage.4 tabs,9 figs,16 refs.%为了解决目前依靠转向灯识别换道意图时因转向灯开启率低而识别遗漏的问题,探索运用驾驶人在不同任务条件下眼动行为存在的差异来识别换道意图.在真实道路环境条件下进行实车试验,采集了16名驾驶人车辆保持阶段和换道意图阶段的眼动行为数据,运用数理统计方法对比分析驾驶人在不同阶段的基本眼动参数、注意力分配和视觉搜索模式3个方面眼动行为参数.研究结果表明:平均注视时间、平均扫视幅度、车道注意力分配、后视镜注意力分配、仪表盘注意力分配、区域间注视转移概率、水平视觉搜索广度等参数在2个阶段存在显

  6. Psicologia social e processo grupal: a coerência entre fazer, pensar sentir em Sívia Lane Social psychology and group process: coherence between doing, thinking and feeling in Sílvia Lane

    Sueli Terezinha Ferreira Martins

    2007-01-01

    Full Text Available O presente artigo trata da concepção histórica e dialética de processo grupal proposta por Sílvia Lane, que utiliza como base para suas reflexões os pressupostos de materialismo dialético quando considera os aspectos pessoais, as características grupais, a vivência subjetiva e a realidade objetiva e o caráter histórico do grupo. O que pretendemos enfatizar neste artigo é a produção sobre grupo presente em sua obra que foi se construindo no decorrer das décadas de 1980 e 1990, sintetizada no texto O processo grupal. Neste sentido, busca-se trazer as contribuições presentes no conjunto de sua obra, sistematizadas em artigos, coletâneas e livros, em que Sílvia Lane discute a articulação de algumas categorias fundamentais para a análise do processo grupal e suas implicações teóricas, metodológicas e prático-políticas.The present article discusses historic and dialectical conceptions of group process by Sílvia Lane, that uses like base for her reflections the presuppositions of dialectical materialism, when the author considers the personal aspects, the group characteristics, the subjective existence and objective reality and the historical character of the group. This article intends to emphasize the production written by Sílvia Lane about group between 1980 and 1990 summaried in the text The group process. In this direction, it searchs to bring the contributions in her work through articles, collections and books that Sílvia Lane discusses some fundamental categories to the analysis of group process and their theoretical and methodological evolvement and practical-politics.

  7. Motorcyclist's lane position as a factor in right-of-way violation collisions: a driving simulator study.

    Sager, Bertrand; Yanko, Matthew R; Spalek, Thomas M; Froc, David J; Bernstein, Daniel M; Dastur, Farhad N

    2014-11-01

    A driver turning left and failing to notice an oncoming motorcyclist until too late is the most common cause of motorcycle collisions. Consequently, much previous research has focused on motorcycle properties, such as size, shape, and color to explain its inconspicuousness. However, collision statistics remain largely unchanged, suggesting that the issue may not be related solely to the motorcycle's static properties. In the present study, we examined a different characteristic of the motorcycle, namely its trajectory of approach. Seventeen participants faced oncoming traffic in a high-fidelity driving simulator and indicated when gaps were safe enough for them to turn left at an intersection. We manipulated the size of the gaps and the type of oncoming vehicle over 135 trials, with gap sizes varying from 3 to 5s, and vehicles consisting of either a car, a motorcycle in the left-of-lane position, or a motorcycle in the right-of-lane position. Our results show that drivers are more likely to turn in front of an oncoming motorcycle when it travels in the left-of-lane position than when it travels in the right-of-lane position. PMID:25108901

  8. 33 CFR 149.560 - How must buoys used to define traffic lanes be marked and lighted?

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false How must buoys used to define traffic lanes be marked and lighted? 149.560 Section 149.560 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND EQUIPMENT Aids to Navigation Lights on...

  9. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle across Two Lanes of Opposing Traffic

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

    2013-01-01

    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous…

  10. Lane Detection in Video-Based Intelligent Transportation Monitoring via Fast Extracting and Clustering of Vehicle Motion Trajectories

    Jianqiang Ren

    2014-01-01

    Full Text Available Lane detection is a crucial process in video-based transportation monitoring system. This paper proposes a novel method to detect the lane center via rapid extraction and high accuracy clustering of vehicle motion trajectories. First, we use the activity map to realize automatically the extraction of road region, the calibration of dynamic camera, and the setting of three virtual detecting lines. Secondly, the three virtual detecting lines and a local background model with traffic flow feedback are used to extract and group vehicle feature points in unit of vehicle. Then, the feature point groups are described accurately by edge weighted dynamic graph and modified by a motion-similarity Kalman filter during the sparse feature point tracking. After obtaining the vehicle trajectories, a rough k-means incremental clustering with Hausdorff distance is designed to realize the rapid online extraction of lane center with high accuracy. The use of rough set reduces effectively the accuracy decrease, which results from the trajectories that run irregularly. Experimental results prove that the proposed method can detect lane center position efficiently, the affected time of subsequent tasks can be reduced obviously, and the safety of traffic surveillance systems can be enhanced significantly.

  11. Two-way multi-lane traffic model for pedestrians in corridors

    Appert-Rolland, Cécile; Motsch, Sébastien

    2011-01-01

    We extend the Aw-Rascle macroscopic model of car traffic into a two-way multi-lane model of pedestrian traffic. Within this model, we propose a technique for the handling of the congestion constraint, i.e. the fact that the pedestrian density cannot exceed a maximal density corresponding to contact between pedestrians. In a first step, we propose a singularly perturbed pressure relation which models the fact that the pedestrian velocity is considerably reduced, if not blocked, at congestion. In a second step, we carry over the singular limit into the model and show that abrupt transitions between compressible flow (in the uncongested regions) to incompressible flow (in congested regions) occur. We also investigate the hyperbolicity of the two-way models and show that they can lose their hyperbolicity in some cases. We study a diffusive correction of these models and discuss the characteristic time and length scales of the instability.

  12. New Analytic Solution to the Lane-Emden Equation of Index 2

    S. S. Motsa

    2012-01-01

    Full Text Available We present two new analytic methods that are used for solving initial value problems that model polytropic and stellar structures in astrophysics and mathematical physics. The applicability, effectiveness, and reliability of the methods are assessed on the Lane-Emden equation which is described by a second-order nonlinear differential equation. The results obtained in this work are also compared with numerical results of Horedt (1986 which are widely used as a benchmark for testing new methods of solution. Good agreement is observed between the present results and the numerical results. Comparison is also made between the proposed new methods and existing analytical methods and it is found that the new methods are more efficient and have several advantages over some of the existing analytical methods.

  13. APPROXIMATE ANALYTICAL SOLUTION FOR THE ISOTHERMAL LANE EMDEN EQUATION IN A SPHERICAL GEOMETRY

    Moustafa Aly Soliman

    2015-01-01

    Full Text Available Este trabajo obtiene una soluci ́on anal ́ıtica aproximada p ara la ecuaci ́on isoterma de Lane-Emden que modela una esfera isot ́ermica au togravitante. La soluci ́on aproximada se obtiene en t ́erminos de par ́ametro s de distancias peque ̃nos y grandes por el m ́etodo de perturbaciones. La soluci ́on apr oximada se compara con la soluci ́on n ́umerica. La soluci ́on aproximada obteni da es v ́alida para todos los valores del par ́ametro de distancia.

  14. APPROXIMATE ANALYTICAL SOLUTION FOR THE ISOTHERMAL LANE EMDEN EQUATION IN A SPHERICAL GEOMETRY

    Moustafa Aly Soliman; Yousef Al-Zeghayer

    2015-01-01

    Este trabajo obtiene una soluci ́on anal ́ıtica aproximada p ara la ecuaci ́on isoterma de Lane-Emden que modela una esfera isot ́ermica au togravitante. La soluci ́on aproximada se obtiene en t ́erminos de par ́ametro s de distancias peque ̃nos y grandes por el m ́etodo de perturbaciones. La soluci ́on apr oximada se compara con la soluci ́on n ́umerica. La soluci ́on aproximada obteni da es v ́alida para todos los valores del par ́ametro de distancia.

  15. Particle acceleration

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  16. Accelerator design

    The feasibility of constructing a TeV region electron-positron linear collider in Japan is discussed. The design target of the collider is given as follows: Energy, 1 TeV + 1 TeV; luminosity, 1032-1033/cm2/s; total length, 25km; electric power, 250MW; energy dispersion, 1%-10%; the start of the first experiment, early 1990s. For realizing the above target, the following research and developmental works are necessary. (a) Development of an acceleration tube with short filling time and high shunt resistance. (b) Short pulse microwave source with high peak power. (c) High current, single bunch linac. (d) Beam dynamics. As for the acceleration tube, some possibility is considered: For example, the use of DAW (Disk and Washer) which is being developed for TRISTAN as a traveling-wave tube; and the Jungle Gym-type acceleration tube. As a promising candidate for the microwave source, the Lasertron has been studied. The total cost of the collider construction is estimated to be about 310 billion yen, of which 120 billion yen is for the tunnel and buildings, and 190 billion yen for the accelerator facilities. The operation cost is estimated to be about 3 billion yen per month. (Aoki, K.)

  17. Accelerator operations

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  18. Visual scanning training for neglect after stroke with and without a computerized lane tracking dual task

    M.E. Van Kessel

    2013-07-01

    Full Text Available Neglect patients typically fail to explore the contralesional half-space. During visual scanning training, these patients learn to consciously pay attention to contralesional target stimuli. It has been suggested that combining scanning training with methods addressing non-spatial attention might enhance training results. In the present study, a dual task training component was added to a visual scanning training (i.e. Training di Scanning Visuospaziale – TSVS; Pizzamiglio et al., 1990. Twenty-nine subacute right hemisphere stroke patients were semi-randomly assigned to an experimental (N=14 or a control group (N=15. Patients received 30 training sessions during six weeks. TSVS consisted of four standardized tasks (digit detection, reading/copying, copying drawings and figure description. Moreover, a driving simulator task was integrated in the training procedure. Control patients practiced a single lane tracking task for two days a week during six weeks. The experimental group was administered the same training schedule, but in weeks 4-6 of the training, the TSVS digit detection task was combined with lane tracking on the same projection screen, so as to create a dual task (CVRT-TR. Various neglect tests and driving simulator tasks were administered before and after training. No significant group and interaction effects were found that might reflect additional positive effects of dual task training. Significant improvements after training were observed in both groups taken together on most assessment tasks. Ameliorations were generally not correlated to post onset time, but spontaneous recovery, test-retest variability and learning effects could not be ruled out completely, since these were not controlled for. Future research might focus on increasing the amount of dual task training, the implementation of progressive difficulty levels in the driving simulator tasks and further exploration of relationships between dual task training and daily

  19. Active training and driving-specific feedback improve older drivers' visual search prior to lane changes

    Lavallière Martin

    2012-03-01

    Full Text Available Abstract Background Driving retraining classes may offer an opportunity to attenuate some effects of aging that may alter driving skills. Unfortunately, there is evidence that classroom programs (driving refresher courses do not improve the driving performance of older drivers. The aim of the current study was to evaluate if simulator training sessions with video-based feedback can modify visual search behaviors of older drivers while changing lanes in urban driving. Methods In order to evaluate the effectiveness of the video-based feedback training, 10 older drivers who received a driving refresher course and feedback about their driving performance were tested with an on-road standardized evaluation before and after participating to a simulator training program (Feedback group. Their results were compared to a Control group (12 older drivers who received the same refresher course and in-simulator active practice as the Feedback group without receiving driving-specific feedback. Results After attending the training program, the Control group showed no increase in the frequency of the visual inspection of three regions of interests (rear view and left side mirrors, and blind spot. In contrast, for the Feedback group, combining active training and driving-specific feedbacks increased the frequency of blind spot inspection by 100% (32.3 to 64.9% of verification before changing lanes. Conclusions These results suggest that simulator training combined with driving-specific feedbacks helped older drivers to improve their visual inspection strategies, and that in-simulator training transferred positively to on-road driving. In order to be effective, it is claimed that driving programs should include active practice sessions with driving-specific feedbacks. Simulators offer a unique environment for developing such programs adapted to older drivers' needs.

  20. Advanced accelerators

    This report discusses the suitability of four novel particle acceleration technologies for multi-TeV particle physics machines: laser driven linear accelerators (linac), plasma beat-wave devices, plasma wakefield devices, and switched power and cavity wakefield linacs. The report begins with the derivation of beam parameters practical for multi-TeV devices. Electromagnetic field breakdown of materials is reviewed. The two-beam accelerator scheme for using a free electron laser as the driver is discussed. The options recommended and the conclusions reached reflect the importance of cost. We recommend that more effort be invested in achieving a self-consistent range of TeV accelerator design parameters. Beat-wave devices have promise for 1-100 GeV applications and, while not directly scalable to TeV designs, the current generation of ideas are encouraging for the TeV regime. In particular, surfatrons, finite-angle optical mixing devices, plasma grating accelerator, and the Raman forward cascade schemes all deserve more complete analysis. The exploitation of standard linac geometry operated in an unconventional mode is in a phase of rapid evolution. While conceptual projects abound, there are no complete designs. We recommend that a fraction of sponsored research be devoted to this approach. Wakefield devices offer a great deal of potential; trades among their benefits and constraints are derived and discussed herein. The study of field limitation processes has received inadequate attention; this limits experiment designers. The costs of future experiments are such that investment in understanding these processes is prudent. 34 refs., 12 figs., 3 tabs

  1. MUON ACCELERATION

    BERG,S.J.

    2003-11-18

    One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

  2. KEKB accelerator

    KEKB, the B-Factory at High Energy Accelerator Research Organization (KEK) recently achieved the luminosity of 1 x 1034 cm-2s-1. This luminosity is two orders higher than the world's level at 1990 when the design of KEKB started. This unprecedented result was made possible by KEKB's innovative design and technology in three aspects - beam focusing optics, high current storage, and beam - beam interaction. Now KEKB is leading the luminosity frontier of the colliders in the world. (author)

  3. Accelerating networks

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  4. 单目智能车道偏离预警系统%Monocular Aptitude Lane Departure Warning System Design

    吕柯岩; 朱明; 贺柏根; 杨粤涛

    2012-01-01

    车道偏离预警系统是继安全气囊之后的汽车安全辅助系统,该系统主要任务是采用基于机器视觉的方法提取车道线并进行预警决策.文章利用TMS320DM642视频处理器作为中央处理器,设计出基于DM642的车道偏离预警系统硬件架构,算法方面对图像进行灰度化、二值化和边缘提取做预处理,然后设置感兴趣区域(ROI),利用基于相位编组的改进Hough变换(RHT)进行车道线检测,根据车道偏离预警条件进行预警决策,当车辆在驾驶员非意识时偏离车道线的情况下实施报警.试验结果证明,本系统能够提前2.5s进行车道偏离的预警工作,并能够排除路面标记的影响,满足车道偏离预警系统实时、鲁棒的性能要求.%Lane Departure Warning System (LDWS) is a car safety assist systems, following the capsule of the safety, whose main task is to extract lane markings and make warning-decision. In this paper, the lane departure warning system hardware architecture is designed based on TMS320DM642 which acts as the central processing unit. The algorithms turn the image into grayscale, and then detect the image's edge information, in the end set the region of interest (ROD on the image. Hough transform based on phase grouping is used to extract the lanes, and according to the lane departure warning conditions, the system analyzes whether the warning should be presented or not and gives the driver warning singles when it is unconscious. The experiments results proved that the system will make warning in 2. 5 s before the traffic accident, which implements the aim of the real-time, reliable lane departure warning.

  5. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  6. accelerating cavity

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  7. Monitoring the newly qualified nurses in Sweden: the Longitudinal Analysis of Nursing Education (LANE study

    Wallin Lars

    2010-04-01

    Full Text Available Abstract Background The Longitudinal Analysis of Nursing Education (LANE study was initiated in 2002, with the aim of longitudinally examining a wide variety of individual and work-related variables related to psychological and physical health, as well as rates of employee and occupational turnover, and professional development among nursing students in the process of becoming registered nurses and entering working life. The aim of this paper is to present the LANE study, to estimate representativeness and analyse response rates over time, and also to describe common career pathways and life transitions during the first years of working life. Methods Three Swedish national cohorts of nursing students on university degree programmes were recruited to constitute the cohorts. Of 6138 students who were eligible for participation, a total of 4316 consented to participate and responded at baseline (response rate 70%. The cohorts will be followed prospectively for at least three years of their working life. Results Sociodemographic data in the cohorts were found to be close to population data, as point estimates only differed by 0-3% from population values. Response rates were found to decline somewhat across time, and this decrease was present in all analysed subgroups. During the first year after graduation, nearly all participants had qualified as nurses and had later also held nursing positions. The most common reason for not working was due to maternity leave. About 10% of the cohorts who graduated in 2002 and 2004 intended to leave the profession one year after graduating, and among those who graduated in 2006 the figure was almost twice as high. Intention to leave the profession was more common among young nurses. In the cohort who graduated in 2002, nearly every fifth registered nurse continued to further higher educational training within the health professions. Moreover, in this cohort, about 2% of the participants had left the nursing

  8. ROADSIDE BARRIER AND PASSIVE SAFETY OF MOTORCYCLISTS ALONG EXCLUSIVE MOTORCYCLE LANES

    A.B. IBITOYE

    2007-04-01

    Full Text Available The tremendous increase in number of motorcycles and fatalities in some ASEAN countries is becoming a main concern for the safety of motorcyclists along exclusive motorcycle lanes. The existing w-beam guardrail system along exclusive motorcycle lanes was originally designed to reduce severity of a crash when cars and trucks involve in run-off road accident – but not specifically to protect motorcyclists during such accident. However, the consequences of this guardrail design on the passive safety of motorcyclist have been given little consideration. Thus, Probability of the motorcyclists getting injured on collision with guardrail is higher compared to other motor vehicle’s driver. In order to investigate the passive safety of motorcyclists while in collision with this guardrail, this study carried out computer simulation of typical crash scenario and conducted a physical crash test to validate the simulation model. The study examines the crash mechanism as related to injury severity when motorcyclist interacts with W-beam guardrail. A three-dimensional computer simulation of a scaled Hybrid III 50th percentile Male dummy mounted on a motorcycle and colliding with W-beam guardrail was carried out. Multi-body model of motorcycle and finite element model of guardrail were developed with commercially available software called MADYMO. The simulation model is validated with a simple crash test conducted with same initial impact configuration. The subsequent simulations were set up for impacting the existing w-beam guardrail with 110 kg motorcycle using eighteen impact conditions that consist of impact angles 15o, 30o and 45o, impact speeds of 32, 48 and 60km/h as well as post spacing of 2m and 4m. The predicted rider’s injury risk criteria were used to assess safety of guardrail response to motorcyclists. The obtained results confirmed that the existing w-beam guardrail is not safe to motorcyclist, especially for the head injury at impact speed

  9. Fast food purchasing and access to fast food restaurants: a multilevel analysis of VicLANES

    Kavanagh Anne M

    2009-05-01

    Full Text Available Abstract Background While previous research on fast food access and purchasing has not found evidence of an association, these studies have had methodological problems including aggregation error, lack of specificity between the exposures and outcomes, and lack of adjustment for potential confounding. In this paper we attempt to address these methodological problems using data from the Victorian Lifestyle and Neighbourhood Environments Study (VicLANES – a cross-sectional multilevel study conducted within metropolitan Melbourne, Australia in 2003. Methods The VicLANES data used in this analysis included 2547 participants from 49 census collector districts in metropolitan Melbourne, Australia. The outcome of interest was the total frequency of fast food purchased for consumption at home within the previous month (never, monthly and weekly from five major fast food chains (Red Rooster, McDonalds, Kentucky Fried Chicken, Hungry Jacks and Pizza Hut. Three measures of fast food access were created: density and variety, defined as the number of fast food restaurants and the number of different fast food chains within 3 kilometres of road network distance respectively, and proximity defined as the road network distance to the closest fast food restaurant. Multilevel multinomial models were used to estimate the associations between fast food restaurant access and purchasing with never purchased as the reference category. Models were adjusted for confounders including determinants of demand (attitudes and tastes that influence food purchasing decisions as well as individual and area socio-economic characteristics. Results Purchasing fast food on a monthly basis was related to the variety of fast food restaurants (odds ratio 1.13; 95% confidence interval 1.02 – 1.25 after adjusting for individual and area characteristics. Density and proximity were not found to be significant predictors of fast food purchasing after adjustment for individual socio

  10. Trails, Bike, Bike Lanes within City of Ashland, WI, Published in 2007, 1:600 (1in=50ft) scale, City of Ashland.

    NSGIC GIS Inventory (aka Ramona) — This Trails, Bike dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Other information as of 2007. It is described as 'Bike Lanes within...

  11. Enabling 4-Lane Based 400 G Client-Side Transmission Links with MultiCAP Modulation

    Tatarczak, Anna; Iglesias Olmedo, Miguel; Zuo, Tianjian; Estaran Tolosa, Jose Manuel; Jensen, Jesper Bevensee; Xu, Xiaogeng; Tafur Monroy, Idelfonso

    2015-01-01

    We propose a uniform solution for a future client-side 400 G Ethernet standard based on MultiCAP advanced modulation format, intensity modulation, and direct detection. It employs 4 local area networks-wavelength division multiplexing (LAN-WDM) lanes in 1300 nm wavelength band and parallel optics...... using off-the-shelf 850 nm VCSEL with 10.1 GHz 3 dB bandwidth is demonstrated indicating the feasibility of achieving 100 Gb/s per lane with a single 25 GHz VCSEL. In this review paper we introduce and present in one place the benefits of MultiCAP as versatile scheme for use in a number of client...

  12. A multiclass vehicular dynamic traffic flow model for main roads and dedicated lanes/roads of multimodal transport network

    We present in this paper a model of vehicular traffic flow for a multimodal transportation road network. We introduce the notion of class of vehicles to refer to vehicles of different transport modes. Our model describes the traffic on highways (which may contain several lanes) and network transit for pubic transportation. The model is drafted with Eulerian and Lagrangian coordinates and uses a Logit model to describe the traffic assignment of our multiclass vehicular flow description on shared roads. The paper also discusses traffic streams on dedicated lanes for specific class of vehicles with event-based traffic laws. An Euler-Lagrangian-remap scheme is introduced to numerically approximate the model’s flow equations

  13. A multiclass vehicular dynamic traffic flow model for main roads and dedicated lanes/roads of multimodal transport network

    Sossoe, K.S., E-mail: kwami.sossoe@irt-systemx.fr [TECHNOLOGICAL RESEARCH INSTITUTE SYSTEMX (France); Lebacque, J-P., E-mail: jean-patrick.lebacque@ifsttar.fr [UPE/IFSTTAR-COSYS-GRETTIA (France)

    2015-03-10

    We present in this paper a model of vehicular traffic flow for a multimodal transportation road network. We introduce the notion of class of vehicles to refer to vehicles of different transport modes. Our model describes the traffic on highways (which may contain several lanes) and network transit for pubic transportation. The model is drafted with Eulerian and Lagrangian coordinates and uses a Logit model to describe the traffic assignment of our multiclass vehicular flow description on shared roads. The paper also discusses traffic streams on dedicated lanes for specific class of vehicles with event-based traffic laws. An Euler-Lagrangian-remap scheme is introduced to numerically approximate the model’s flow equations.

  14. Modern strain localization in the central Walker Lane, western United States: Implications for the evolution of intraplate deformation in transtensional settings

    Surpless, Benjamin

    2008-10-01

    Approximately 25% of the differential motion between the Pacific and North American plates occurs in the Walker Lane, a zone of dextral motion within the western margin of the Basin and Range province. At the latitude of Lake Tahoe, the central Walker Lane has been considered a zone of transtension, with strain accommodated by dip-slip, strike-slip, and oblique-slip faults. Geologic data indicate that extension and strike-slip motion are partitioned across the central Walker Lane, with dip-slip motion resulting in E-W to ESE-WNW extension along the present-day western margin of the central Walker Lane since approximately 15 Ma, and dextral strike-slip motion across a zone further east since as early as 24 Ma. GPS velocity data suggest that present-day strain continues to be strongly partitioned and localized across the same regions established by geologic data. Velocity data across the central Walker Lane suggest a minimum of 2 mm/yr extensional strain focused along the western margin of the belt, with very little extension across either the central or eastern portions of the Walker Lane. These data indicate very little dextral motion across the central and western portions of the domain, with dextral motion of 3-5 mm/yr presently focused along a discrete zone of the eastern part of the central Walker Lane, coincident with existing, mapped strike-slip faults. Historic seismic data reveal little seismic activity in areas of Late Holocene dip-slip motion in the west or dextral motion in the east, suggesting a period of quiescence in the earthquake cycle and the likelihood of future activity in both areas. Based on this and previous studies, it is likely that a combination of pre-Cenozoic crustal structure, a relatively weak lithosphere beneath the Walker Lane, and long-term low stress ratios in the crust have permitted the long-term partitioning of dextral and extensional strain exhibited across the central Walker Lane. The present-day location of dextral strain in

  15. Electron Accelerator Facilities

    Lecture presents main aspects of progress in development of industrial accelerators: adaptation of accelerators primary built for scientific experiments, electron energy and beam power increase in certain accelerator constructions, computer control system managing accelerator start-up, routine operation and technological process, maintenance (diagnostics), accelerator technology perfection (electrical efficiency, operation cost), compact and more efficient accelerator constructions, reliability improvement according to industrial standards, accelerators for MW power levels and accelerators tailored for specific use

  16. Can carpooling clean the air? The economics of HOV lanes, hybrid cars and the Clean Air Act.

    Shewmake, Sharon

    2010-01-01

    Private vehicles are a significant source of air pollution in many areas of the United States. Areas with already high levels of air pollution are required by the Clean Air Act to take steps to reduce automobile use and the associated emissions. The behavioral implications of many travel demand management techniques are poorly understood. In this dissertation I focus on carpooling. Policy makers encourage commuters to carpool through High Occupancy Vehicle (HOV) Lanes, fre...

  17. Asymptotic Stability of the Lane-Emden Solutions for the Viscous Gaseous Star Problem with Degenerate Density Dependent Viscosities

    Luo, Tao; Xin, Zhouping; Zeng, Huihui

    2015-01-01

    The nonlinear asymptotic stability of Lane-Emden solutions is proved in this paper for spherically symmetric motions of viscous gaseous stars with the density dependent shear and bulk viscosities which vanish at the vacuum, when the adiabatic exponent $\\gamma$ lies in the stability regime $(4/3, 2)$, by establishing the global-in-time regularity uniformly up to the vacuum boundary for the vacuum free boundary problem of the compressible Navier-Stokes-Poisson systems with spherical symmetry, w...

  18. Car accidents and number of stopped cars due to road blockage on a one-lane highway

    Boccara, N.; Fuks, H.; Zeng, Q.

    1997-01-01

    Within the framework of a simple model of car traffic on a one-lane highway, we study the probability for car accidents to occur when drivers do not respect the safety distance between cars, and, as a result of the blockage during the time $T$ necessary to clear the road, we determine the number of stopped cars as a function of car density. We give a simple theory in good agreement with our numerical simulations.

  19. A New Genetic Algorithm Based Lane-By-Pass Approach for Smooth Traffic Flow on Road Networks

    Shailendra Tahilyani; Manuj Darbari; Praveen Kumar Shukla

    2012-01-01

    Traffic congestion in urban areas is a very critical problem and increasing day-by-day due to increment in number of vehicles and un-expandable traffic infrastructure. Several intelligent control systems have been developed to deal with this issue. In this paper, a new lane bypass algorithm has been developed for route diversion resulting in smooth traffic flow on the urban road networks. Genetic algorithms are utilized for the parameter optimization in this approach. Finally, the results of ...

  20. Design of Control and Monitoring System to Avoid Inter-Ship Collisions in West Shipping Lane Tanjung Perak Surabaya

    Devina P. Sari; Aulia S. Aisjah; A.A. Masroeri

    2012-01-01

    The occurrence of several ship accidents in narrow waters of Madura strait which is the west shipping lane of Tanjung Perak Surabaya has inspired the research on the design of a control system on the ship to avoid any collision between ships. The existence of automatic control with the autopilot is required to minimize the occurrence of collisions between ships In this final study investigated the application of fuzzy logic to control the yaw angle on the vessel MV Karana Sembilan. Fuzzy logi...

  1. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle Across Two Lanes of Opposing Traffic

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

    2012-01-01

    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications – bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous cross traffic coming from opposing directions. Opportunities for crossing were divided into aligned (far gap opens with or before near gap) and rolli...

  2. A Comparative Systems-level Analysis: Automated Freeways, Hov Lanes, Transit Expansion, Pricing Policies And Land Use Intensification

    Johnston, Robert

    1997-01-01

    The focus of this project was to examine the potential travel, emissions, and consumer benefits of advanced freeway automation and travel demand management measures. The Sacramento Regional Travel Demand model (SACMET 95) was used to simulate the travel effects of travel demand management measures in the Sacramento region for a twenty year time horizon. The scenarios examined included various combinations of automated freeways, new High Occupancy Vehicle (HOV) lanes, transit, land use intensi...

  3. A Simplified Method for Calculating Propeller Thrust Decrease for a Ship Sailing on a Given Shipping Lane

    Zelazny Katarzyna

    2014-04-01

    Full Text Available During ship sailing on rough water, relative ship motions can be observed which make the propeller emerge from the water, and decrease its thrust as a consequence. The article presents a simplified method for calculating the thrust decrease and the time of propeller emergence from water for the ship on a regular an irregular wave. The method can be used for predicting the operating speed of the ship on a given shipping lane.

  4. Analysing adjustment factors for using lanes at traffic-light-controlled intersections in Bogotá, Colombia.

    Ricardo José Peña Lindarte

    2010-05-01

    Full Text Available This article was focused on analyzing the lane use adjustment factor (fLU forming one of the eleven adjustment factors proposed in the current calculation methodology contained in the 2000 version of the Transportation Research Board’s (TRB Highway Capacity Manual (HCM for analyzing traffic-light-controlled intersection capacity in terms of saturation intensity. A methodology was established when analyzing the fLU factor that considered operational conditions regarding traffic-light-controlled intersections in Bogota. Road traffic flows were analyzed, including characterizing road traffic based on statistical sampling, field data collection and analysis. The project proposed equations allowing reference values to be gathered for determining adjustment factors regarding lane use on roads in Bogota in relation to existing access typologies and road traffic volume for analyzing traffic-light- controlled intersections. For example, in the specific case of roads having direct double-lane access (2CCD, the basic equation was determined to be y=-3,03E-08X2+3,44E-05X+0,888988, having a 1.0 coefficient of correlation. The dependent variable y referred to the fLU factor and the independent variable X was the volume of road traffic in mixed vehicles/hour. This equation was considered to be statistically relevant. A comparative analysis of the lane use adjustment factors estimated in the project is also presented and compared to the values recommended by the US Highway Capacity Manual. The project’s conclusions and re- commendations were thus sustained, validating the recommended factors summarized by the HCM and recommending that the results obtained from the project should be used in traffic-light-controlled design and planning projects.

  5. Comment on: Microscopic modeling of multi-lane highway traffic flow, Nathan O. Hodas and Arnand Jagota, Am. J. Phys. 71 (12) 2003, pp. 1247

    Risch, M.

    2006-01-01

    In heavy traffic with congested roadway the maximum traffic flow also depends on length of cars. This is deduced in a simple derivation suited for classroom demonstration as well as homework. The resulting equation demonstrates a new relation to an apparently unrelated area of physics, the maximum ship velocity (hull speed) and explains why traffic is sometimes faster on the slow lane on a congested multi-lane road.

  6. Analysis of a novel two-lane lattice model on a gradient road with the consideration of relative current

    Cao, Jin-Liang; Shi, Zhong-Ke

    2016-04-01

    In this paper, a novel hydrodynamic lattice model is proposed by considering of relative current for two-lane gradient road system. The stability condition is obtained by using linear stability theory and shown that the stability of traffic flow varies with three parameters, that is, the slope, the sensitivity of response to the relative current and the rate of lane changing. The stable region increases with the increasing of one of them when another two parameters are constant. By using nonlinear analysis, the Burgers, Korteweg-de Vries, and modified Korteweg-de Vries equations are derived to describe the phase transition of traffic flow. Their solutions present the density wave as the triangular shock wave, soliton wave, and kink-antikink wave in the stable, metastable, and unstable region, respectively, which can explain the phase transitions from free traffic to stop-and-go traffic, and finally to congested traffic. To verify the theoretical results, a series of numerical simulations are carried out. The numerical results are consistent with the analytical results. To check the novel model, calibration are taken based on the empirical traffic flow data. The theoretical results and numerical results show that the traffic flow on the gradient road becomes more stable and the traffic congestion can be efficiently suppressed by considering the relative current and lane changing, and the empirical analysis shows that the novel lattice model is reasonable.

  7. A two-lane cellular automaton traffic flow model with the influence of driver, vehicle and road

    Zhao, Han-Tao; Nie, Cen; Li, Jing-Ru; Wei, Yu-Ao

    2016-07-01

    On the basis of one-lane comfortable driving model, this paper established a two-lane traffic cellular automata model, which improves the slow randomization effected by brake light. Considering the driver psychological characteristics and mixed traffic, we studied the lateral influence between vehicles on adjacent lanes. Through computer simulation, the space-time diagram and the fundamental figure under different conditions are obtained. The study found that aggressive driver makes a slight congestion in low-density traffic and improves the capacity of high-density traffic, when the density exceeds 20pcu/km the more aggressive drivers the greater the flow, when the density below 40pcu/km driver character makes an effect, the more cautious driver, the lower the flow. The ratio of big cars has the same effect as the ratio of aggressive drivers. Brake lights have the greatest impact on traffic flow and when the density exceeds 10pcu/km the traffic flow fluctuates. Under periodic boundary conditions, the disturbance of road length on traffic is minimal. The lateral influence only play a limited role in the medium-density conditions, and only affect the average speed of traffic at low density.

  8. Driving simulator evaluation of drivers' response to intersections with dynamic use of exit-lanes for left-turn.

    Zhao, Jing; Yun, Meiping; Zhang, H Michael; Yang, Xiaoguang

    2015-08-01

    With the worsening of urban traffic congestion in large cities around the world, researchers have been looking for unconventional designs and/or controls to squeeze more capacity out of intersections, the most common bottlenecks of the road network. One of these innovative intersection designs, known as the exit-lanes for left-turn (EFL), opens up exit-lanes to be used by left-turn traffic with the help of an additional traffic light installed at the median opening (the pre-signal). This paper studies how drivers respond to EFL intersections with a series of driving simulator experiments. In our experiments, 64 drivers were recruited and divided into two groups. One group is trained to use the EFL while the other group is not. In addition, four scenarios were considered with different sign and marking designs and traffic conditions in the experiments. Results indicate that drivers show certain amount of confusion and hesitation when encountering an EFL intersection for the first time. They can be overcome, however, by increasing exposure through driver education or by cue provided from other vehicles. Moreover, drivers unfamiliar with EFL operation can make a left turn using the conventional left-turn lanes as usual. The EFL operation is not likely to pose any serious safety risk of the intersection in real life operations. PMID:25969158

  9. SDS-PAGE in conjunction with match lane statistical analysis for the detection of meat adulteration

    Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of seven meat types and two component mixtures of them were made. Banding patterns of resulting denstograms in conjunction with cluster analysi and match lane statistical analysis were used for the detection of meat adulteration. The use of beef as a reference meat have resulted in a clear distinction from goat, pork, chicken, turkey, camel meats and their mixture and camel meat. The use of pork meat as a reference was more assurate because of the low degrees of matching with all meats and their mixtures and consequently high abilities of differentiations. The purpose of identification. the purpose of identification of meat species arises from the desire of human, in general, to confirm what he eat ? for moslems the establisment that meat is free from pork type is most important. Another economic purpose is the detection of adulteration of valuable meat by less valuable types. Several attempts in different laboratories were done to serve this object but most of analytical techniques. Barbieri and formi (1999) were able to detect 5% of meat type in mixtures by isolelectric focusing and 1% of meat type by PCR technique in beef, pork, chicken and turkey meats. By crossover immunoelectrophoresis technique, zanon and vianello (1998) were also to detect a limit of 5% of specific meat in mixuters of beef, pork, mutton/lamb, horse and chicken meats

  10. Evaluating User Response to In-Car Haptic Feedback Touchscreens Using the Lane Change Test

    Matthew J. Pitts

    2012-01-01

    Full Text Available Touchscreen interfaces are widely used in modern technology, from mobile devices to in-car infotainment systems. However, touchscreens impose significant visual workload demands on the user which have safety implications for use in cars. Previous studies indicate that the application of haptic feedback can improve both performance of and affective response to user interfaces. This paper reports on and extends the findings of a 2009 study conducted to evaluate the effects of different combinations of touchscreen visual, audible, and haptic feedback on driving and task performance, affective response, and subjective workload; the initial findings of which were originally published in (M. J. Pitts et al., 2009. A total of 48 non-expert users completed the study. A dual-task approach was applied, using the Lane Change Test as the driving task and realistic automotive use case touchscreen tasks. Results indicated that, while feedback type had no effect on driving or task performance, preference was expressed for multimodal feedback over visual alone. Issues relating to workload and cross-modal interaction were also identified.

  11. X-Ray Emission from a prominent dust lane lenticular galaxy NGC 5866

    Vagshette, N D; Pandey, S K; Patil, M K

    2015-01-01

    We report the multiband imagery with an emphasis on the X-ray emission properties of a prominent dust lane lenticular galaxy NGC 5866. X-ray emission from this galaxy is due to a diffuse component and a substantial contribution from the population of discrete X-ray binary sources. A total of 22 discrete sources have been detected within the optical D25 extent of the galaxy, few of which exhibit spatial association with the globular clusters hosted by this system. Composite spectrum of the diffuse emission from this galaxy was well constrained by a thermal plasma model plus a power law component to represent the emission from unresolved sources, while that of the discrete sources was well fitted by an absorbed power law component of photon index 1.82$\\pm$0.14. X-ray color-color plot for the resolved source was used to classify the detected sources. The cumulative X-ray luminosity function of the XRBs is well represented by a power law function of index of {\\Gamma} ~ 0.82$\\pm$0.12. Optical imagery of NGC 5866 r...

  12. Results of the radiological survey at 7 Redstone Lane, Lodi, New Jersey (LJ044)

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally 232Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclides analyses. The survey of this site, 7 Redstone Lane, Lodi, New Jersey (LJ044), was conducted during 1985 and 1986. Some radionuclide measurements were greater than typical background levels in the northern New Jersey area. However, results of the survey demonstrated no radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. 5 refs., 4 figs., 3 tabs

  13. Production and composition of oranges cv. Lane Late under maintenance potassium fertilization

    Gustavo Brunetto

    2016-04-01

    Full Text Available Este estudo teve como objetivo avaliar a produção e composição de laranjas de cv. Pista árvores tardias submetido a adubação de manutenção de potássio. O experimento foi conduzido em um pomar de cv. Lane Late em Rosário do Sul (RS. As laranjeiras foram submetidos a suplementação com 0, 50 ou 100% da dose recomendada de K2O em cada safra de 2008/2009 a 2011/2012. A produção de frutos, diâmetro do fruto, espessura da casca, volume de suco e suco, folha e os níveis de K no solo foram avaliados nas safras 2008/2009, 2010/2011 e 2011/2012. parâmetros de composição da fruta foram avaliados nos 2010/2011 e 2011/2012 safras. A aplicação de doses crescentes de potássio para CV. Pista laranjeiras atrasado para três safras não teve efeito sobre a produção de frutos. No entanto, a suplementação do solo com o potássio aumentou os níveis de nutrientes totais nas folhas e suco.

  14. Collective Dynamics on a Two-Lane Asymmetrically Coupled TASEP with Mutually Interactive Langmuir Kinetics

    Gupta, Arvind Kumar

    2016-03-01

    Motivated by the recent experimental observations on clustering of motor proteins on microtubule filament, we study an open system of two parallel totally asymmetric simple exclusion processes under asymmetric coupling conditions, which incorporates the mutual interaction with the surrounding environment through Langmuir Kinetics (LK) in both the lanes. In the modified LK, the attachment and detachment rates depends on the configuration of nearest neighboring sites. We analyse the model within the framework of continuum mean-field theory and the phase diagrams along with density profiles are obtained using boundary layer analysis. The effect of mutual interactions on the phase diagram for two different situations of attachment and detachment (LK) rates is discussed. Under the symmetric LK dynamics, the topological structure of the phase diagram remains similar to the one in without mutual interaction; while for the antisymmetric case, after a certain critical value of attractive/repulsive mutual attraction, significant changes are found in the qualitative nature of phase diagram. Moreover, it is shown that the type of mutual interaction affects the dynamic properties of motor proteins. The theoretical findings are examined by extensive Monte-Carlo simulations.

  15. Results of the radiological survey at 112 Columbia Lane, Lodi, New Jersey (LJ068)

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally 232Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 112 Columbia Lane, Lodi, New Jersey (LJ068), was conducted during 1987. 4 refs., 6 figs., 3 tabs

  16. Polynomial-time homology for simplicial Eilenberg-MacLane spaces

    Krcal, Marek; Sergeraert, Francis

    2012-01-01

    In an earlier paper of Cadek, Vokrinek, Wagner, and the present authors, we investigated an algorithmic problem in computational algebraic topology, namely, the computation of all possible homotopy classes of maps between two topological spaces, under suitable restriction on the spaces. We aim at showing that, if the dimensions of the considered spaces are bounded by a constant, then the computations can be done in polynomial time. In this paper we make a significant technical step towards this goal: we show that the Eilenberg-MacLane space K(Z,1), represented as a simplicial group, can be equipped with polynomial-time homology (this is a polynomial-time version of effective homology considered in previous works of the third author and co-workers). To this end, we construct a suitable discrete vector field, in the sense of Forman's discrete Morse theory, on K(Z,1). The construction is purely combinatorial and it can be understood as a certain procedure for reducing finite sequences of integers, without any re...

  17. Automatic parsing of lane and road boundaries in challenging traffic scenes

    Helala, Mohamed A.; Qureshi, Faisal Z.; Pu, Ken Q.

    2015-09-01

    Automatic detection of road boundaries in traffic surveillance imagery can greatly aid subsequent traffic analysis tasks, such as vehicle flow, erratic driving, and stranded vehicles. This paper develops an online technique for identifying the dominant road boundary in video sequences captured by traffic cameras under challenging environmental and lighting conditions, e.g., unlit highways captured at night. The proposed method works in real time of up to 20 frames/s and generates a ranked list of road regions that identify road and lane boundaries. Our method begins by segmenting each frame into a set of superpixels. An adaptive sampling step approximates superpixel contours to a collection of edge segments. Next, we show how online hierarchical clustering can be efficiently used to organize edges into clusters of colinearly similar sets. Promising clusters are paired with each other to form cluster pairs. Then we present and prove a statistical ranking measure that is used along with road-activity and perspective cues to find the dominant road boundaries. We evaluate the proposed approach on two real-world datasets to test our method under camera viewpoint changes and extreme environmental and lighting conditions. Results show that our method outperforms two state-of-the-art techniques in precision, recall, and runtime.

  18. Keeping Energy Savings in the LOOP: Mesa Lane Partners Case Study

    None

    2013-03-01

    Mesa Lane Partners (MLP) partnered with the U.S. Department of Energy (DOE) to develop and implement solutions to a build a new, low-energy mixed-use building that consumes at least 50% less energy than requirements set by Energy Standard 90.1-2007 of the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE), the American National Standards Institute (ANSI), and the Illuminating Engineering Society of America (IESNA), as part of DOE’s Commercial Building Partnerships (CBP) Program. Lawrence Berkeley National Laboratory (LBNL) provided technical expertise in support of this DOE program. The privately developed 46,000-square-foot LOOP project, which is intended to provide affordable off-campus student housing in an underserved community next to University of California at Santa Barbara, will contain more than 7,000 square feet of retail space, a roof deck, an event space, a gym, and 48 apartments. The project developer, MLP, is aiming to exceed CBP requirement, targeting energy consumption that is at least 65% less than that required by the standard. If the LOOP meets this goal, it is expected to achieve Leadership in Energy and Environmental Design (LEED) Gold certification.

  19. Method for environmental risk analysis of marine terminals, process industry terminals, pipelines and shipping lanes

    Nissen-Lie, Torild R.; Aspholm, Ole O. [DNV Energy, Oslo (Norway)

    2008-07-01

    The paper describes a quantitative method for analyzing the environmental risk of marine terminals, process industry terminals, pipelines and shipping lanes. The method has been used both in Norway and elsewhere in the world; calculating the risk for environmental resources as fish, seabirds and waterfowls, marine mammals, otters, sea turtles and salt marches and other shoreline/sub tidal habitats. The environmental risk is the product of the probability of acute releases and the environmental consequences. Consequences for vulnerable species and habitats are calculated based on oil drift modelling results and a consequence matrix consisting of 5-7 consequence parameter and five consequence levels of increasing seriousness. An average consequence level is calculated on basis of defined weighting factors to provide an overall consequence value for each spill scenario for each species/habitat. An environmental risk analysis highlights the hazards that have to be managed in order to run an environmentally sustainable operation and can also provide input to establish cost-effective oil spill response measures. (author)

  20. Accelerator system and method of accelerating particles

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  1. Calibration of safety performance function for crashes on inter-city four lane highways in India

    Naveen Kumar ChikkaKrishna

    2015-12-01

    Full Text Available There is a significant need to improve the highway safety during roadway planning, design and operations in developing countries like India. To receive appropriate consideration, safety needs to be dealt objectively within the transportation planning and highway design processes. Lack of available tools is a deterrent to quantify safety of a transportation facility during the planning or highway design process. The objective of this paper is to develop safety performance functions considering various elements involved in the planning, design and operation of a section on four-lane National Highway (NH-58 located in the state of Uttarakhand, India. The mixed traffic on Indian multilane highways comes with a lot of variability within, ranging from different vehicle types to different driver characteristics. This could result in variability in the effect of explanatory variables on crashes across locations. Hence, explanatory variables for highway segment safety analysis considered were geometric characteristics like curvature change rate, slope change rate, transverse slope and traffic characteristics in the form of average daily traffic, light vehicle traffic, light commercial vehicle traffic, heavy vehicle traffic, two-wheelers, non-motorised traffic volume and operating speed were analysed against dependent variable as crash count per 200 m per year. Safety performance functions involving the explanatory variables are calibrated to predict crash frequency using Poisson Weibull technique and crash types are predicted using ordered logit model. Model results suggest that increase in traffic volume leads to higher probability of crash risk and traffic safety is significantly distorted by higher curvature change rate values.

  2. Pulsed DC accelerator for laser wakefield accelerator

    For the acceleration of ultra-short, high-brightness electron bunches, a pulsed DC accelerator was constructed. The pulser produced megavolt pulses of 1 ns duration in a vacuum diode. Results are presented from field emission of electrons in the diode. The results indicate that the accelerating gradient in the diode is approximately 1.5 GV/m

  3. Linear Accelerator (LINAC)

    ... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays to ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...

  4. A case study on multi-lane roundabouts under congestion: Comparing software capacity and delay estimates with field data

    Xuanwu Chen

    2016-04-01

    Full Text Available Existing studies on modern roundabouts performance are mostly based on data from singe lane roundabouts that are not heavily congested. For planners and designers interested in building multilane roundabouts for intersections with potential growth in future traffic, there has been a lack of existing studies with field data that provide reference values in terms of capacity and delay measurements. With the intent of providing such reference values, a case study was conducted by using the East Dowling Road Roundabouts in Anchorage, Alaska, which are currently operating with extensive queues during the evening peak hours. This research used multiple video camcorders to capture vehicle turning movements at the roundabouts as well as the progression of vehicle queues at the roundabout entrance approaches. With these video records, the number of vehicles in the queues can be accurately counted in any single minute during the peak hours. This study shows that unbalanced entrance flow patterns (i.e., one entrance has significant higher flow than others can intensify the queue and delay for the overall roundabouts. Then various software packages including RODEL, SIDRA and VISSIM were used to estimate several performance measurements, such as capacity, queue length, and delay, compared with the collected field data. With the comparison, it is found that all the three software packages overestimate multi-lane roundabout capacity before calibration. With default parameters, SIDRA and VISSIM tend to underestimate delays and queue lengths for the multi-lane roundabouts under congestion, while RODEL results in higher delay and queue length estimations at most of the entrance approaches.

  5. Perception of Safety and Liking Associated to the Colour Intervention of Bike Lanes: Contribution from the Behavioural Sciences to Urban Design and Wellbeing

    Vera-Villarroel, Pablo; Contreras, Daniela; Lillo, Sebastián; Segovia, Ariel; Rojo, Natalia; Moreno, Sandra; Oyarzo, Francisco

    2016-01-01

    The perception of colour and its subjective effects are key issues to designing safe and enjoyable bike lanes. This paper addresses the relationship between the colours of bike lane interventions—in particular pavement painting and intersection design—and the subjective evaluation of liking, visual saliency, and perceived safety related to such an intervention. Utilising images of three real bike lane intersections modified by software to change their colour (five in total), this study recruited 538 participants to assess their perception of all fifteen colour-design combinations. A multivariate analysis of covariance (MANCOVA) with the Bonferroni post hoc test was performed to assess the effect of the main conditions (colour and design) on the dependent variables (liking towards the intervention, level of visual saliency of the intersection, and perceived safety of the bike lane). The results showed that the colour red was more positively associated to the outcome variables, followed by yellow and blue. Additionally, it was observed that the effect of colour widely outweighs the effect of design, suggesting that the right choice and use of colour would increase the effectiveness on bike-lanes pavement interventions. Limitations and future directions are discussed. PMID:27548562

  6. Tectonic Tales: Changes in Central Walker Lane Strain Accommodation near Bridgeport, California; as told by the Stanislaus Group

    Carlson, C. W.; Pluhar, C. J.; Glen, J. M.

    2010-12-01

    The Late-Miocene Stanislaus Group of lavas and ignimbrites were deposited across a region of diverse tectonic rates and style. Distributed east of Sonora Pass across the Walker Lane Belt into Nevada, and extending as far west as Knights Ferry along the Stanislaus River in the central Sierran foothills, the Stanislaus Group’s distinctive lithologic and paleomagnetic characteristics provide the means to reconstruct tectonic evolution in this region. Motion of the Sierra Nevada microplate is relatively straightforward while the adjacent range front fault and Walker Lane are characterized by westward propagation with time, extensive complex faulting, and vertical axis rotation of fault bounded blocks. The Stanislaus Group is composed of: 1) Table Mountain Formation, dominantly latite lavas emplaced at about ~10 Ma, 2A) Tollhouse Flat Member of the dominantly quartz latite Eureka Valley Tuff (EVT), emplaced sometime during 9.4-9.8 Ma, 2B) Latite Flow Member of EVT, 2C) By-Day Member of EVT, 9.42±0.04 Ma, 2D) Upper Member of EVT 9.43±0.02 Ma, and 3) Dardanelle Formation, composed of latite lavas, which caps the Stanislaus Group. Because of wide areal distribution across the central Walker Lane, we have used members of the Stanislaus Group to evaluate and understand regional strain in this part of the North American-Pacific plate boundary, which currently accommodates ~25% of relative dextral plate motion. Paleomagnetic analysis has yielded multiple reference remanence directions for elements of the Stanislaus Group on the “relatively stable” Sierra Nevada microplate for comparison with those same units deposited within the extensively-faulted Walker Lane to the east. Preliminary results show tectonic domains near Bridgeport, CA in the 5-10 km size range displaying eastward-increasing vertical-axis block rotation. This west-to-east increase in rotation appears to sub-parallel the Sierran frontal fault system when analyzed with data from previous studies to the

  7. Penny Lane et Strawberry Field(s : réel, identité et fantasmagorie

    Bernard Gensane

    2010-11-01

    Full Text Available Les chansons « Penny Lane » et « Strawberry Fields Forever » permettent d’appréhender le thème de l’enfance chez les Beatles. De manière très différente, John Lennon et Paul McCartney s’appuient sur une visite de deux lieux réels liverpooliens pour mettre en résonance leurs visions fantasmagoriques du passé, et pour exploiter la langue (qu’ils travaillent et qui les travaille dans une perspective authentiquement artistique.

  8. Enabling 4-Lane Based 400 G Client-Side Transmission Links with MultiCAP Modulation

    Anna Tatarczak; Miguel Iglesias Olmedo; Tianjian Zuo; Jose Estaran; Jesper Bevensee Jensen; Xiaogeng Xu; Idelfonso Tafur Monroy

    2015-01-01

    We propose a uniform solution for a future client-side 400 G Ethernet standard based on MultiCAP advanced modulation format, intensity modulation, and direct detection. It employs 4 local area networks-wavelength division multiplexing (LAN-WDM) lanes in 1300 nm wavelength band and parallel optics links based on vertical cavity surface emitting lasers (VCSELs) in 850 nm wavelength band. Total bit rate of 432 Gbps is transmitted over unamplified 20 km standard single mode fiber link and over 40...

  9. The zhou’s method for solving the nonlinear lane-emden type equations: a special case

    Cárdenas, Pedro P.; Devia, Diana M.; Mesa, Fernando

    2013-01-01

    In this work we apply the differential transformation method (the Zhou’s method) for solving some classes of Lane- Emden type equations as a model for the dimensionless density distribution in an isothermal gas sphere, which are nonlinear ordinary differential equations on the semi-infinite domain, as a special case y′′ + 2 y′ +ey = 0 and y′′ + 2 y′ + e−y = 0. Differential transformation method may be considered as alternative and efficient for finding the approximate solutions of the initial...

  10. Quad 14Gbps L-Band VCSEL-based System for WDM Migration of 4-lanes 56 Gbps Optical Data Links

    Estaran Tolosa, Jose Manuel; Rodes Lopez, Roberto; Pham, Tien Thang;

    2012-01-01

    We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty.......We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty....

  11. Acceleration without Horizons

    Doria, Alaric; Munoz, Gerardo

    2015-01-01

    We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} < c$. The motion of the accelerating observer is completely determined by the distance of closest approach and terminal velocity or, equivalently, by an acceleration parameter and terminal velocity.

  12. Switching lanes: Exploring the strategic repositioning of the Kenyan tea industry.

    Gatuguta, Susan Mwende

    2006-01-01

    Research into the performance of primary commodities has shown a number of factors present in the global arena act as impediments to market stability. The tea industry is no exception to the rule as the global tea industry is facing a number of challenges which threaten the livelihood of tea producers. Tea producers have primarily focused on traditional primary commodities but this is not sustainable in future due to accelerated global competition. This paper seeks to look at the challenges a...

  13. 行进在快车道上的中国环境社会学%China Environmental Sociology Stepping onto Express Lane

    洪大用; 龚文娟

    2015-01-01

    本文基于对2011—2014年中国环境社会学研究成果的再分析,指出中国环境社会学已经行驶在快车道上,呈现出加速发展之势,在环境与社会的关系以及环境问题的社会原因、社会影响和社会应对等方面都取得了一些有价值的研究成果. 未来中国环境社会学研究需要保持清醒、冷静的头脑,进行必要的、建设性的反思,进一步完善学术对话机制、加强基础理论与方法研究,在经验研究中更加重视信息技术革命背景下的环境传播、环境政策发展过程及其实践分析等领域,并以一种更加积极乐观而又科学客观的态度,进一步加强对特定地区、特定行业和企业实施环境治理成功经验的调查研究和理论总结.%Based on re-analysis to China's environmental sociology research in 2011—2014, the article points out that China's environmental sociology has already stepped onto an express lane, showing a trend of accelerated development, achieving some valuable research findings in relationship between environment and society, social causes of, impact and reactions to environmental problems. Future studies need to done with consciousness and reasonability, with necessary and constructive reflection, to further improve the academic dialogue mechanism, strengthen research in basic theories and research methods. While in empirical studies, more attention should be attached to environment communication, environmental policy development and practice analysis under the IT revolution background. A more positive and optimistic but scientific and objective attitude should be developed to make further research and a theoretical summary to successful practice of environmental management in particular areas, industries and enterprises.

  14. High intensity hadron accelerators

    In this paper we give an introductory discussion of high intensity hadron accelerators with special emphasis on the high intensity feature. The topics selected for this discussion are: Types of acclerator - The principal actions of an accelerator are to confine and to accelerate a particle beam. Focusing - This is a discussion of the confinement of single particles. Intensity limitations - These are related to confinement of intense beams of particles. Power economics - Considerations related to acceleration of intense beams of particles. Heavy ion kinematics - The adaptation of accelerators to accelerate all types of heavy ions

  15. The direction of acceleration

    Wilhelm, Thomas; Burde, Jan-Philipp; Lück, Stephan

    2015-11-01

    Acceleration is a physical quantity that is difficult to understand and hence its complexity is often erroneously simplified. Many students think of acceleration as equivalent to velocity, a ˜ v. For others, acceleration is a scalar quantity, which describes the change in speed Δ|v| or Δ|v|/Δt (as opposed to the change in velocity). The main difficulty with the concept of acceleration therefore lies in developing a correct understanding of its direction. The free iOS app AccelVisu supports students in acquiring a correct conception of acceleration by showing acceleration arrows directly at moving objects.

  16. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  17. 33 CFR 149.565 - What are the required characteristics and intensity of lights on buoys used to define traffic lanes?

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What are the required characteristics and intensity of lights on buoys used to define traffic lanes? 149.565 Section 149.565 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND...

  18. San Francisco Accelerator Conference

    'Where are today's challenges in accelerator physics?' was the theme of the open session at the San Francisco meeting, the largest ever gathering of accelerator physicists and engineers

  19. Dielectric Laser Acceleration

    England, R. Joel; Noble, Robert J.; Wu, Ziran; Qi, Minghao

    2013-01-01

    We describe recent advances in the study of particle acceleration using dielectric near-field structures driven by infrared lasers, which we refer to as Dielectric Laser Accelerators. Implications for high energy physics and other applications are discussed.

  20. Standing wave linear accelerator

    Consideration is being given to standing wave linear accelerator containing generator, phase shifter, two accelerating resonator sections, charged particle injector and waveguide bridge. Its first arm is oined up with generator via the phase shifter, the second and the third ones-with accelerating sections and the fourth one - with HF-power absorber. HF-power absorber represents a section of circular diaphragmatic wavequide with transformer with input wave and intrawaveguide output load located between injector and the first accelerating section. The section possesses holes in side walls lying on accelerator axis. The distances between centers of the last cell of the fast accelerating section and the first cell of the second accelerating sectiOn equal (2n+3)lambda/4, where n=1, 2, 3..., lambda - wave length of generator. The suggested system enables to improve by one order spectral characteristics of accelerators as compared to the prototype in which magnetrons are used as generator

  1. Improved plasma accelerator

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  2. High Energy Particle Accelerators

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  3. Assessing Level of Service of Two Lane Highways Using User Perception and Its Relationship With Field Measurements

    Minu S

    2015-11-01

    Full Text Available Level of Service (LOS is an important measure of performance of highways. The primary measure of service quality for two lane highways based on highway capacity manual are percent time spent following and average travel speed which are not directly based on user perception. In addition to speed and delay the road users perceive other attributes in their subjective determination of LOS. A methodology based on fuzzy set approach and fuzzy clustering is presented to determine the LOS that explicitly accounts for user perception. Several attributes contributing to road user perceptions of LOS were identified using a questionnaire survey and composite level of service was obtained by combining all attributes together using fuzzy weighted average and fuzzy C means clustering techniques. The levels of service obtained were compared with that obtained using field procedure recommended in HCM 2000.

  4. Stopping Accidents before They Happen: Perceiving Lane-Level Moving Vehicle Danger Regions to Warn Surrounding Drivers and Pedestrians

    Chi Guo

    2016-01-01

    Full Text Available Perceiving the location of dangerous moving vehicles and broadcasting this information to vehicles nearby are essential to achieve active safety in the Internet of Vehicles (IOV. To address this issue, we implement a real-time high-precision lane-level danger region service for moving vehicles. A traditional service depends on static geofencing and fails to deal with dynamic vehicles. To overcome this defect, we devised a new type of IOV service that manages to track dangerous moving vehicles in real time and recognize their danger regions quickly and accurately. Next, we designed algorithms to distinguish the vehicles in danger regions and broadcast the information to these vehicles. Our system can simultaneously manipulate a mass of danger regions for various dangerous vehicles and broadcast this information to surrounding vehicles at a large scale. This new system was tested in Shanghai, Guangzhou, Wuhan, and other cities; the data analysis is presented in this paper as well.

  5. Evaluation of geodetic and geologic datasets in the Northern Walker Lane-Summary and recommendations of the Workshop

    Briggs, Richard W.; Hammond, William C.

    2010-01-01

    The Northern Walker Lane comprises a complex network of active faults in northwestern Nevada and northeastern California bound on the west by the Sierra Nevada and on the east by the extensional Basin and Range Province. Because deformation is distributed across sets of discontinuous faults, it is particularly challenging to integrate geologic and geodetic data in the NWL to assess the region's seismic hazard. Recent GPS measurements show that roughly one centimeter per year of relative displacement is accumulating across a zone about 100 km wide at the latitude of Reno, Nevada, but it is not clear where or how much of this strain might ultimately be released in damaging earthquakes. Despite decades of work in the region, the sum of documented late Pleistocene to recent slip rates is distinctly less than the GPS-measured relative displacement.

  6. Maximal Acceleration Is Nonrotating

    Page, Don N.

    1997-01-01

    In a stationary axisymmetric spacetime, the angular velocity of a stationary observer that Fermi-Walker transports its acceleration vector is also the angular velocity that locally extremizes the magnitude of the acceleration of such an observer, and conversely if the spacetime is also symmetric under reversing both t and phi together. Thus a congruence of Nonrotating Acceleration Worldlines (NAW) is equivalent to a Stationary Congruence Accelerating Locally Extremely (SCALE). These congruenc...

  7. Accelerators at school

    Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required

  8. A Solid state accelerator

    We present a solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal. Acceleration gradients of order 100 GV/cm are theoretically possible, but channeling radiation limits the maximum attainable energy to 105 TeV for protons. Beam dechanneling due to multiple scattering is substantially reduced by the high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed

  9. Superconducting accelerator technology

    Modern and future accelerators for high energy and nuclear physics rely increasingly on superconducting components to achieve the required magnetic fields and accelerating fields. This paper presents a practical overview of the phenomenon of superconductivity, and describes the design issues and solutions associated with superconducting magnets and superconducting rf acceleration structures. Further development and application of superconducting components promises increased accelerator performance at reduced electric power cost

  10. Applications of particle accelerators

    Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)

  11. EFFECT OF CONGESTION ON FUEL COST AND TRAVEL TIME COST ON MULTI-LANE HIGHWAYS IN INDIA

    Madhu Errampalli

    2015-12-01

    Full Text Available The vehicles normally move at their free speeds when it is least impeded due to traffic flow under lean traffic (free flow conditions. As traffic flow increases, the vehicles cannot sustain their free speeds due to interactions from other vehicles in the traffic stream. In addition to that the vehicles that are operating in the congested traffic conditions will consume more fuel than those operating in steady state traffic conditions for the same average speed. This leads to increase in travel time and fuel consumption of the vehicles and thereby adding to total road user cost (RUC. On the contrary, fuel consumption is also high at very high speeds under free flow traffic flow conditions leading to increase RUC. Considering these scenarios, the travel time and fuel cost of the vehicle due to the congestion and free flow conditions (uncongested has to be necessarily modelled in order to estimate realistic assessment of RUC on Indian highways. In the present study, the congestion cost relationships have been developed between Congestion Factor, a ratio of cost under congestion and steady state conditions and Volume-Capacity Ratio by considering various vehicle types plying on varying widths of multi-lane highways (four, six and eight lane divided carriageways through the collection of exhaustive time related and fuel related data. Time related data was collected through questionnaire survey method whereas fuel consumption data was collected using advanced sophisticated fuel flow measuring equipment (V-Box. The developed equations have been successfully applied to demonstrate their applicability in terms of estimating realistic effect of congestion on time and fuel cost by considering a section on NH-2 in Delhi. The analysis shows that the congestion effect is more significant on fuel cost for heavy commercial vehicles whereas it is more prominent on time cost for passenger vehicles. However, the congestion effect on combined fuel and time cost is

  12. Cost evaluation of irradiation system with electron accelerator

    The features of electron beam irradiation system using electron accelerator are direct energy pour into the irradiated material, no third material mixture such as catalyst, suitable for mass production and easy operation and maintenance work available. These features can bring the various applications such as cross-linking action, graft polymerization, radical polymerization and others. The selection of electron accelerator ratings is made under consideration of quality, width and thickness of irradiated material, production amount, dose required for reaction and irradiation atmosphere. Especially in a case of irradiation of wire with high insulation material such as polyethylene, the consideration of maximum thickness toward irradiation direction is necessary to avoid the discharge (Lichtenberg discharge) by charged-up electrons inside insulation material. Therefore, the acceleration voltage should be selected to make the maximum penetration larger than maximum irradiation thickness. The actual model case of estimate the irradiation cost was selected that the irradiation object was polyethylene insulated wire up to AWG no.14, irradiation amount was 5,000 km/month, necessary dose was 200 kGy, operation time was 22 d/month and 8 h/day and actual operation efficiency was considered loss time such as bobbin changing as 80%. The selected ratings of electron accelerator were acceleration voltage of 800 kV, beam current of 100 mA and irradiation width of 180 cm with irradiation pulleys stand of 60 turns x 3 lanes. The initial total cost was estimated as 3 M$(US) and operation cost was evaluated as 215 k$(US). Therefore, the irradiation cost of wire was evaluated as 0.0036 $/m. (author)

  13. Accelerator development in BARC

    Charged particle accelerators have played crucial role in the field of both basic and applied sciences. This has been possible because the accelerators have been extensively utilized from unraveling the secrets of nature to diverse applications such as implantation, material modification, medical diagnostics and therapy, nuclear energy and clean air and water. The development of accelerators in BARC can be categorized in two broad categories namely proton and heavy ion based accelerators and electron based accelerators. The heavy ion accelerators with sufficiently high energies are currently being used for conducting frontline nuclear and allied research whereas the electron accelerators are being routinely used for various industrial applications. Recently, there is a strong interest for developing the high energy and high intensity accelerators due to their possibility of effective utilization towards concept of energy amplification (Accelerator Driven System), incineration nuclear waste and transmutation. This talk will discuss details of the accelerator development program in BARC with particular emphasis on the recent development at Low Energy High Intensity Proton Accelerator (LEHIPA) Facility in Ion Accelerator Development Division, BARC. (author)

  14. Far field acceleration

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  15. The CERN Accelerator School

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  16. Accelerators and Dinosaurs

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  17. Acceleration: It's Elementary

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  18. The Accelerator Reliability Forum

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  19. Direct Laser Acceleration in Laser Wakefield Accelerators

    Shaw, Jessica

    2016-01-01

    In this dissertation, the direct laser acceleration (DLA) of ionization-injected electrons in a laser wakefield accelerator (LWFA) operating in the quasi-blowout regime has been investigated through experiment and simulation. In the blowout regime of LWFA, the radiation pressure of an intense laser pulse can push a majority of the plasma electrons out and around the main body of the pulse. The expelled plasma electrons feel the electrostatic field of the relatively-stationary ions and are t...

  20. The future of particle accelerators

    Plasma-based accelerators are developing as credible, and compact, accelerators for the future. We review the status and prospects for electron and proton accelerators using laser Wakefield acceleration. (author)

  1. The application of active-source seismic imaging techniques to transtensional problems the Walker Lane and Salton Trough

    Kell, Anna Marie

    The plate margin in the western United States is an active tectonic region that contains the integrated deformation between the North American and Pacific plates. Nearly focused plate motion between the North American and Pacific plates within the northern Gulf of California gives way north of the Salton Trough to more diffuse deformation. In particular a large fraction of the slip along the southernmost San Andreas fault ultimately bleeds eastward, including about 20% of the total plate motion budget that finds its way through the transtensional Walker Lane Deformation Belt just east of the Sierra Nevada mountain range. Fault-bounded ranges combined with intervening low-lying basins characterize this region; the down-dropped features are often filled with water, which present opportunities for seismic imaging at unprecedented scales. Here I present active-source seismic imaging from the Salton Sea and Walker Lane Deformation Belt, including both marine applications in lakes and shallow seas, and more conventional land-based techniques along the Carson range front. The complex fault network beneath the Salton Trough in eastern California is the on-land continuation of the Gulf of California rift system, where North American-Pacific plate motion is accommodated by a series of long transform faults, separated by small pull-apart, transtensional basins; the right-lateral San Andreas fault bounds this system to the north where it carries, on average, about 50% of total plate motion. The Salton Sea resides within the most youthful and northerly "spreading center" in this several thousand-kilometer-long rift system. The Sea provides an ideal environment for the use of high-data-density marine seismic techniques. Two active-source seismic campaigns in 2010 and 2011 show progression of the development of the Salton pull-apart sub-basin and the northerly propagation of the Imperial-San Andreas system through time at varying resolutions. High fidelity seismic imagery

  2. Particle-accelerator decommissioning

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

  3. An introduction to acceleration mechanisms

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration

  4. Accelerator and radiation physics

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  5. Leaky Fermi accelerators

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  6. Accelerator reliability workshop

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  7. Nuclear physics accelerator facilities

    This paper describes many of the nuclear physics heavy-ion accelerator facilities in the US and the research programs being conducted. The accelerators described are: Argonne National Laboratory--ATLAS; Brookhaven National Laboratory--Tandem/AGS Heavy Ion Facility; Brookhaven National Laboratory--Relativistic Heavy Ion Collider (RHIC) (Proposed); Continuous Electron Beam Accelerator Facility; Lawrence Berkeley Laboratory--Bevalac; Lawrence Berkeley Laboratory--88-Inch Cyclotron; Los Alamos National Laboratory--Clinton P. Anderson Meson Physics Facility (LAMPF); Massachusetts Institute of Technology--Bates Linear Accelerator Center; Oak Ridge National Laboratory--Holifield Heavy Ion Research Facility; Oak Ridge National Laboratory--Oak Ridge Electron Linear Accelerator; Stanford Linear Accelerator Center--Nuclear Physics Injector; Texas AandM University--Texas AandM Cyclotron; Triangle Universities Nuclear Laboratory (TUNL); University of Washington--Tandem/Superconducting Booster; and Yale University--Tandem Van de Graaff

  8. Accelerator reliability workshop

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  9. Switched Matrix Accelerator

    We describe a new concept for a microwave circuit functioning as a charged-particle accelerator at mm-wavelengths, permitting an accelerating gradient higher than conventional passive circuits can withstand consistent with cyclic fatigue. The device provides acceleration for multiple bunches in parallel channels, and permits a short exposure time for the conducting surface of the accelerating cavities. Our analysis includes scalings based on a smooth transmission line model and a complementary treatment with a coupled-cavity simulation. We provide also an electromagnetic design for the accelerating structure, arriving at rough dimensions for a seven-cell accelerator matched to standard waveguide and suitable for bench tests at low power in air at 91.392. GHz. A critical element in the concept is a fast mm-wave switch suitable for operation at high-power, and we present the considerations for implementation in an H-plane tee. We discuss the use of diamond as the photoconductor switch medium

  10. CAS - CERN Accelerator School: RF for Accelerators

    2012-01-01

    These proceedings present the lectures given at the twenty-fourth specialized course organized by the CERN Accelerator School (CAS). The course was held in Ebeltoft, Denmark, from 8-17 June, 2010 in collaboration with Aarhus University, with the topic 'RF for Accelerators' While this topic has been covered by CAS previously, early in the 1990s and again in 2000, it was recognized that recent advances in the field warranted an updated course. Following introductory courses covering the background physics, the course attempted to cover all aspects of RF for accelerators; from RF power generation and transport, through cavity and coupler design, electronics and low level control, to beam diagnostics and RF gymnastics. The lectures were supplemented with several sessions of exercises, which were completed by discussion sessions on the solutions.

  11. Accelerator shielding benchmark problems

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  12. Accelerator shielding benchmark problems

    Hirayama, H.; Ban, S.; Nakamura, T. [and others

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author).

  13. The foxhole accelerating structure

    This report examines some properties of a new type of open accelerating structure. It consists of a series of rectangular cavities, which we call foxholes, joined by a beam channel. The power for accelerating the particles comes from an external radiation source and enters the cavities through their open upper surfaces. Analytic and computer calculations are presented showing that the foxhole is a suitable structure for accelerating relativistic electrons

  14. Japan Accelerator Conference

    At the international level, the high energy accelerator scene evolves rapidly and the International Conference on High Energy Accelerators is where its strong pulse can best be felt. This year, the Conference was held for the first time in Japan, with the 14th meeting in the series having been hosted in August by the Japanese KEK National Laboratory for High Energy Physics, Tsukuba. The venue was a recognition of the premier accelerator physics and technology status achieved by this diligent nation

  15. Superconducting accelerator magnets

    In the near future, a large number of high quality superconducting dipole and quadrupole magnets will be required for construction of the next generation multi-TeV high energy hadron accelerator-colliders. To establish the construction technology of such accelerator- colliders, extensive and world-wide R and D programs are now carrying out at several laboratories. In this paper the important issues in superconducting accelerator magnets such as cables, design, fabrication, testing and cryogenic system are discussed together with some details on coil cross- sectional current configurations, quality control of materials, quench protections, radiation heating and etc. The key technology in superconducting accelerator magnets is summarized

  16. High Gradient Accelerator Research

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  17. High-intensity accelerators

    The design of high-intensity accelerators is described, using examples of machines being built at the Los Alamos National Laboratory. The major design problem with these accelerators is associated with control of beam loss when accelerator intensity is increased. Beam dynamics, beam loss, and the radio-frequency quadrupole structure are discussed in the first part of the chapter followed by an explanation of plans to achieve high-intensity operation in three projects: the Fusion Material Irradiation Tests (a joint effort with the Hanford Development Laboratory in Richland, Washington), the Proton Storage Ring (an addition to the LAMPF accelerator), and the Racetrack Microtron Project

  18. Temperature profile and water depth data collected from USCGC HARRIET LANE using BT and XBT casts in the Northwest Atlantic Ocean from 21 July 1988 to 18 August 1988 (NODC Accession 8800256)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC HARRIET LANE in the Northwest Atlantic Ocean. Data were collected from...

  19. Temperature profile and water depth data collected from USCGC HARRIOT LANE using BT and XBT casts in the NW Atlantic Ocean for 1987-05-31 (NODC Accession 8700225)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the USCGC Harriot Lane in the Northwest Atlantic Ocean and TOGA Area - Atlantic...

  20. Modeling the Impact of Alternative Immunization Strategies: Using Matrices as Memory Lanes.

    Wladimir J Alonso

    Full Text Available Existing modeling approaches are divided between a focus on the constitutive (micro elements of systems or on higher (macro organization levels. Micro-level models enable consideration of individual histories and interactions, but can be unstable and subject to cumulative errors. Macro-level models focus on average population properties, but may hide relevant heterogeneity at the micro-scale. We present a framework that integrates both approaches through the use of temporally structured matrices that can take large numbers of variables into account. Matrices are composed of several bidimensional (time×age grids, each representing a state (e.g. physiological, immunological, socio-demographic. Time and age are primary indices linking grids. These matrices preserve the entire history of all population strata and enable the use of historical events, parameters and states dynamically in the modeling process. This framework is applicable across fields, but particularly suitable to simulate the impact of alternative immunization policies. We demonstrate the framework by examining alternative strategies to accelerate measles elimination in 15 developing countries. The model recaptured long-endorsed policies in measles control, showing that where a single routine measles-containing vaccine is employed with low coverage, any improvement in coverage is more effective than a second dose. It also identified an opportunity to save thousands of lives in India at attractively low costs through the implementation of supplementary immunization campaigns. The flexibility of the approach presented enables estimating the effectiveness of different immunization policies in highly complex contexts involving multiple and historical influences from different hierarchical levels.

  1. Computing the coefficients for the power series solution of the Lane-Emden equation with the Python library SymPy

    Rohe, Klaus

    2014-01-01

    It is shown how the Python library Sympy can be used to compute symbolically the coefficients of the power series solution of the Lane-Emden equation (LEE). Sympy is an open source Python library for symbolic mathematics. The power series solutions are compared to the numerically computed solutions using matplotlib. The results of a run time measurement of the implemented algorithm are discussed at the end.

  2. Angular velocities, angular accelerations, and coriolis accelerations

    Graybiel, A.

    1975-01-01

    Weightlessness, rotating environment, and mathematical analysis of Coriolis acceleration is described for man's biological effective force environments. Effects on the vestibular system are summarized, including the end organs, functional neurology, and input-output relations. Ground-based studies in preparation for space missions are examined, including functional tests, provocative tests, adaptive capacity tests, simulation studies, and antimotion sickness.

  3. Accelerator Modeling with MATLAB Accelerator Toolbox

    This paper introduces Accelerator Toolbox (AT)--a collection of tools to model storage rings and beam transport lines in the MATLAB environment. The objective is to illustrate the flexibility and efficiency of the AT-MATLAB framework. The paper discusses three examples of problems that are analyzed frequently in connection with ring-based synchrotron light sources

  4. Milky Way demographics with the VVV Survey III. Evidence for a Great Dark Lane in the 157 Million Star Bulge Color-Magnitude Diagram

    Minniti, D; Gonzalez, O A; Zoccali, M; Rejkuba, M; Alonso-Garcia, J; Benjamin, R; Catelan, M; Dekany, I; Emerson, J P; Hempel, M; Lucas, P W; Schultheis, M

    2014-01-01

    The new generation of IR surveys are revealing and quantifying Galactic features, providing an improved 3-D interpretation of our own Galaxy. We present an analysis of the global distribution of dust clouds in the bulge using the near-IR photometry of 157 million stars from the VVV Survey. We investigate the color magnitude diagram of the Milky Way bulge which shows a red giant clump of core He burning stars that is split in two color components, with a mean color difference of (Z-Ks)=0.55 magnitudes equivalent to A_V=2.0 magnitudes. We conclude that there is an optically thick dust lane at intermediate latitudes above and below the plane, that runs across several square degrees from l=-10 deg to l=+10 deg. We call this feature the "Great Dark Lane". Although its exact distance is uncertain, it is located in front of the bulge. The evidence for a large-scale great dark lane within the Galactic bulge is important in order to constrain models of the barred Milky Way bulge and to compare our galaxy with external...

  5. Design of Control and Monitoring System to Avoid Inter-Ship Collisions in West Shipping Lane Tanjung Perak Surabaya

    Devina P. Sari

    2012-11-01

    Full Text Available The occurrence of several ship accidents in narrow waters of Madura strait which is the west shipping lane of Tanjung Perak Surabaya has inspired the research on the design of a control system on the ship to avoid any collision between ships. The existence of automatic control with the autopilot is required to minimize the occurrence of collisions between ships In this final study investigated the application of fuzzy logic to control the yaw angle on the vessel MV Karana Sembilan. Fuzzy logic used is Sugeno Takagi type with the input of the error yaw, yaw rate and distance of the ship with a disturbance. Tests conducted with a control system without disturbance, with disturbance, and the presence of obstacles in front of the ship. Performance of control system is obtained by using the disturbance, the fuzzy appearance is 2:41 hm distance position, the speed of 7.5 knots and 0.5 error, then the resulting yaw angle is 6580. Results control with fuzzy syncronized with monitoring at M&C system in visual basic. The view of the monitoring, 3 types of scenarios obtained. For the first scenario, which is created with the control on it, produces the best results of the avoidance, if compared to the second scenario, with trajectory and control anti-collision cross, and if compared with the third scenario that has no built control system with decision-making on it.

  6. A study of the scour-fill threshold based on Lane's equilibrium relation: The lower Yellow River

    Xu, Jiongxin

    2015-12-01

    The scour-fill threshold in river channels is an expression of scour-fill equilibrium, which may be understood as the balance between the river's sediment carrying capability and the sediment load imposed by the drainage basin. In the present study, the above capability-load relation is quantified using Lane's relation, γQJ-QsD50, wherein Q is water discharge, J is channel slope, Qs is sediment transport rate, D50 is median size of bed material, and γ is the specific weight of water. On this basis, we have established scour-fill thresholds for the lower Yellow River based on data from 141 flood events. The results show that the QsD50-γQJ relation may well distinguish between the scour and fill flood events. The following equation has been established: SDRFE = 0.00099(γQJ)0.90(QsD50)- 0.60, wherein SDRFE is channel sediment delivery ratio. From the equation, the scour-fill threshold is established as: QsD50 = 0.00001(γQJ)1.5. Starting from this formula, four possible options are proposed for sediment management of the lower Yellow River.

  7. Place, Capital Flows and Property Regimes: The Elites’ Former Houses in Beijing’s South Luogu Lane

    Zhifen Cheng

    2014-12-01

    Full Text Available Place is seen as a process whereby social and cultural forms are reproduced. This process is closely linked to capital flows, which are, in turn, shaped by changing property regimes. However, relatively little attention has been paid to the relationship between property regimes, capital flows and place-making. The goal of this paper is to highlight the role of changing property regimes in the production of place. Our research area is South Luogu Lane (SLL in Central Beijing. We take elites’ former houses in SLL as the main unit of analysis in this study. From studying this changing landscape, we draw four main conclusions. First, the location of SSL was critical in enabling it to emerge as a high-status residential community near the imperial city. Second, historical patterns of capital accumulation influenced subsequent rounds of private investment into particular areas of SLL. Third, as laws relating to the ownership of land and real estate changed fundamentally in the early 1950s and again in the 1980s, the target and intensity of capital flows into housing in SLL changed too. Fourth, these changes in capital flow are linked to ongoing changes in the place image of SLL.

  8. Accelerator-based BNCT

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the 9Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. - Highlights: • The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. • Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. • The present status and recent progress of the Argentine project will be reviewed. • Topics cover intense ion sources, accelerator tubes, transport of intense beams and beam diagnostics, among others

  9. COLLECTIVE-FIELD ACCELERATION

    Sessler, Andrew M.

    1969-07-04

    Diverse methods proposed for the acceleration of particles by means of collective fields are reviewed. A survey is made of the various currently active experimental programs devoted to investigating collective acceleration, and the present status of the research is briefly noted.

  10. Racetrack linear accelerators

    An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)

  11. Hamburg Accelerator Conference (2)

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). The HEACC Conference traditionally reviews the status of all major accelerator projects whether they are already running like clockwork, still in the construction phase, or waiting impatiently for financial approval

  12. Asia honours accelerator physicists

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  13. Accelerators for energy production

    A tremendous progress of accelerators for these several decades, has been motivated mainly by the research on subnuclear physics. The culmination in high energy accelerators might be SSC, 20 TeV collider in USA, probably the ultimate accelerator being built with the conventional principle. The technology cultivated and integrated for the accelerator development, can now stably offer the high power beam which could be used for the energy problems. The Inertial Confinement Fusion (ICF) with high current, 10 kA and short pulse, 20 ns heavy ion beam (HIB) of mass number ∼200, would be the most promising application of accelerators for energy production. In this scenario, the fuel containing D-T mixture, will be compressed to the high temperature, ∼10 keV and to the high density state, ∼1000 times the solid density with the pressure of ablative plasma or thermal X ray produced by bombarding of high power HIB. The efficiency, beam power/electric power for accelerator, and the repetition rate of HIB accelerators could be most suitable for the energy production. In the present paper, the outline of HIB ICF (HIF) is presented emphasizing the key issues of high current heavy ion accelerator system. (author)

  14. KEK digital accelerator

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  15. Accelerators Beyond The Tevatron?

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  16. Accelerator for nuclear transmutation

    A review on nuclear transmutation of radioactive wastes using particle accelerators is given. Technical feasibility, nuclear data, costs of various projects are discussed. It appears that one high energy accelerator (1500 MeV, 300 mA proton) could probably handle the amount of actinides generated by the actual French nuclear program

  17. Thoughts of accelerator tubes

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  18. Maximal Acceleration Is Nonrotating

    Page, D N

    1998-01-01

    In a stationary axisymmetric spacetime, the angular velocity of a stationary observer that Fermi-Walker transports its acceleration vector is also the angular velocity that locally extremizes the magnitude of the acceleration of such an observer, and conversely if the spacetime is also symmetric under reversing both t and phi together. Thus a congruence of Nonrotating Acceleration Worldlines (NAW) is equivalent to a Stationary Congruence Accelerating Locally Extremely (SCALE). These congruences are defined completely locally, unlike the case of Zero Angular Momentum Observers (ZAMOs), which requires knowledge around a symmetry axis. The SCALE subcase of a Stationary Congruence Accelerating Maximally (SCAM) is made up of stationary worldlines that may be considered to be locally most nearly at rest in a stationary axisymmetric gravitational field. Formulas for the angular velocity and other properties of the SCALEs are given explicitly on a generalization of an equatorial plane, infinitesimally near a symmetry...

  19. Collinear wake field acceleration

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  20. Plasma based accelerators

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  1. Controllable Laser Ion Acceleration

    Kawata, S.; Kamiyama, D.; Ohtake, Y.; Takano, M.; Barada, D.; Kong, Q.; Wang, P. X.; Gu, Y. J.; Wang, W. M.; Limpouch, J.; Andreev, A.; Bulanov, S. V.; Sheng, Z. M.; Klimo, O.; Psikal, J.; Ma, Y. Y.; Li, X. F.; Yu, Q. S.

    2016-02-01

    In this paper a future laser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. Especially a collimation device is focused in this paper. The future laser ion accelerator should have an ion source, ion collimators, ion beam bunchers, and ion post acceleration devices [Laser Therapy 22, 103(2013)]: the ion particle energy and the ion energy spectrum are controlled to meet requirements for a future compact laser ion accelerator for ion cancer therapy or for other purposes. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching would be successfully realized by a multistage laser-target interaction.

  2. Linear induction accelerator

    This paper examines a new layout for the injector and accelerating sectins of a linear induction accelerator. The sections are combined in a single housing: an induction system with a current-pulse generator based on double strip shaping lines laid over ferromagnetic cores; a multichannel spark discharger with forced current division among channels; and a system for core demagnetization and electron-beam formation and transport. The results of formation of an electron beam in the injector system and its acceleration in the first accelerating section of the accelerator for injection of beams with energies of 0.2-0.4 MeV, currents of 1-2 kA, and pulse durations of 60 nsec are given

  3. Video-based lane detection and tracking algorithm%基于视频序列的车道线检测和跟踪

    朱淋; 梁华为; 王智灵; 邓耀

    2013-01-01

    The lane detection is a critical technology for unmanned driving system and a series of driving assistance systems.Traditional lane detection algorithms are easily disturbed by the other traffic lines on the road.A new method for lane detection and tracking is put forward in this paper.First,the adaptive image threshold algorithm is adopted for lane features extraction.By means of setting the ROI twice and planning the tracking region,the ROI decreases gradually.At last,the feature points in the ROI are transformed from the image coordinate system to the real-world coordinate system before they are used to accomplish curve fitting through least square method.Experiments under various conditions,such as highway and urban environments,show that the method proposed in this paper is able to accurately recognize the lane marks in real time and effectively eliminate the disturbance of the other traffic line markings.%车道线检测是无人驾驶系统以及一系列辅助驾驶系统的关键技术环节.传统的车道线检测方法容易受到其他交通标志线干扰,提出了一种新的车道线检测与跟踪方法.该方法首先使用自适应阈值算法提取特征,通过ROI二次设置以及跟踪区域规划,逐步减小感兴趣区域,最后将感兴趣区域内的特征点从图像坐标系转换到世界坐标系下,以最小二乘方法进行曲线拟合.在高速公路及城区道路等多种工况下的实验表明,提出的方法能够正确实时的识别出车道线,有效的消除了其他交通标线的干扰.

  4. Accelerator programme at CAT

    The Accelerator Programme at the Centre for Advanced Technology (CAT), Indore, has very broad based concept under which all types of accelerators are to be taken up for design and fabrication. This centre will be housing a wide variety of accelerators to serve as a common facility for the universities, national laboratories in addition to laboratories under the Department of Atomic Energy. In the first phase of the programme, a series of electron accelerators are designed and fabricated. They are synchrotron radiation sources of 450 MeV (INDUS-I) and of 2 GeV (INDUS-II), microtron upto energy of 20 MeV, linear accelerator upto 20 MeV, and DC Accelerator for industrial irradiation upto 750 KeV and 20 KW. A proton accelerator of 300 MeV with 20 MeV linac injector is also designed. CAT is also developing a strong base for support technologies like ultra high vacuum, radio frequency and microwaves, DC pulsed and superconducting magnets, power supplies and controls etc. These technologies are very useful for other industrial applications also. To develop user groups to utilise INDUS-II synchrotron radiation source, a batch production of rotating Anode X-ray generators with power supplies has been initiated. So also, the sputter ion pumps, electron guns, turbo molecular pumps are brought into batch production. (author)

  5. The miniature accelerator

    Antonella Del Rosso

    2015-01-01

    The image that most people have of CERN is of its enormous accelerators and their capacity to accelerate particles to extremely high energies. But thanks to some cutting-edge studies on beam dynamics and radiofrequency technology, along with innovative construction techniques, teams at CERN have now created the first module of a brand-new accelerator, which will be just 2 metres long. The potential uses of this miniature accelerator will include deployment in hospitals for the production of medical isotopes and the treatment of cancer. It’s a real David-and-Goliath story.   Serge Mathot, in charge of the construction of the "mini-RFQ", pictured with the first of the four modules that will make up the miniature accelerator. The miniature accelerator consists of a radiofrequency quadrupole (RFQ), a component found at the start of all proton accelerator chains around the world, from the smallest to the largest. The LHC is designed to produce very high-intensity beams ...

  6. Collective ion acceleration

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

  7. Collective ion acceleration

    Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

    1977-01-01

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed.

  8. Large electrostatic accelerators

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  9. RF linear accelerators

    Wangler, Thomas P

    2008-01-01

    Thomas P. Wangler received his B.S. degree in physics from Michigan State University, and his Ph.D. degree in physics and astronomy from the University of Wisconsin. After postdoctoral appointments at the University of Wisconsin and Brookhaven National Laboratory, he joined the staff of Argonne National Laboratory in 1966, working in the fields of experimental high-energy physics and accelerator physics. He joined the Accelerator Technology Division at Los Alamos National Laboratory in 1979, where he specialized in high-current beam physics and linear accelerator design and technology. In 2007

  10. Entropic accelerating universe

    Easson, Damien A., E-mail: easson@asu.ed [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Department of Physics and School of Earth and Space Exploration and Beyond Center, Arizona State University, Phoenix, AZ 85287-1504 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 (United States); Frampton, Paul H., E-mail: frampton@physics.unc.ed [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599 (United States); Smoot, George F., E-mail: gfsmoot@lbl.go [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Physics Department, University of California, Berkeley, CA 94720 (United States); Institute for the Early Universe, Ewha Womans University and Advanced Academy, Seoul (Korea, Republic of); Chaire Blaise Pascale, Universite Paris Denis Diderot, Paris (France)

    2011-01-31

    To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann-Lemaitre equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the entropy and temperature intrinsic to the horizon of the universe due to the information holographically stored there. Dark energy is thereby obviated and the acceleration is due to an entropic force naturally arising from the information storage on the horizon surface screen. We consider an additional quantitative approach inspired by surface terms in general relativity and show that this leads to the entropic accelerating universe.

  11. Entropic accelerating universe

    To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann-Lemaitre equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the entropy and temperature intrinsic to the horizon of the universe due to the information holographically stored there. Dark energy is thereby obviated and the acceleration is due to an entropic force naturally arising from the information storage on the horizon surface screen. We consider an additional quantitative approach inspired by surface terms in general relativity and show that this leads to the entropic accelerating universe.

  12. ACCELERATORS: School prizes

    Dedicated to its goal of encouraging scientists and students to work in the field of particle accelerators, the US Particle Accelerator School (operating since 1981) has switched to a new format. Starting this year, it will offer in alternate years basic accelerator physics plus advanced subjects in both university and symposium styles over four weeks. Expanding the school from two to four weeks gives additional flexibility, and undergraduate participation should be encouraged by university credits being offered for particular courses. In the intervening years, the school will organize six-day topical courses

  13. FMIT accelerator vacuum system

    The Fusion Materials Irradiation Test (FMIT) Facility accelerator is being designed to continuously accelerate 100-mA deuterons to 25 MeV. High vacuum pumping of the accelerator structure and beam lines will be done by ion pumps and titanium sublimation pumps. The design of the roughing system includes a Roots blower/mechanical pump package. For economy the size of the system has been designed to operate at 10-6 torr, where beam particle scattering on residual gases is negligible. For minimum maintenance in this neutron factory, the FMIT vacuum system is designed from the point of view of simplicity and reliability

  14. Hadron accelerators in medicine

    The application of hadron accelerators (protons and light ions) in cancer therapy is discussed. After a brief introduction on the rationale for the use of heavy charged particles in radiation therapy, a discussion is given on accelerator technology and beam delivery systems. Next, existing and planned facilities are briefly reviewed. The Italian Hadron-therapy Project is then described in some detail, with reference ro both the National Centre for Oncological Hadron-therapy and the design of different types of compact proton accelerators aimed at introducing proton therapy in a large umber of hospitals. (author)

  15. The auroral electron accelerator

    A model of the auroral electron acceleration process is presented in which the electrons are accelerated resonantly by lower-hybrid waves. The essentially stochastic acceleration process is approximated for the purposes of computation by a deterministic model involving an empirically derived energy transfer function. The empirical function, which is consistent with all that is known of electron energization by lower-hybrid waves, allows many, possibly all, observed features of the electron distribution to be reproduced. It is suggested that the process occurs widely in both space and laboratory plasmas. (author)

  16. Confronting Twin Paradox Acceleration

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  17. Auroral electron acceleration

    Two theories of auroral electron acceleration are discussed. Part 1 examines the currently widely held view that the acceleration is an ordered process in a quasi-static electric field. It is suggested that, although there are many factors seeming to support this theory, the major qualifications and uncertainties that have been identified combine to cast serious doubt over its validity. Part 2 is devoted to a relatively new interpretation in terms of stochastic acceleration in turbulent electric fields. This second theory, which appears to account readily for most known features of the electron distribution function, is considered to provide a more promising approach to this central question in magnetospheric plasma physics. (author)

  18. Accelerated simulated tempering

    We propose a new stochastic global optimization method by accelerating the simulated tempering scheme with random walks executed on a temperature ladder with various transition step sizes. By suitably choosing the length of the transition steps, the accelerated scheme enables the search process to execute large jumps and escape entrapment in local minima, while retaining the capability to explore local details, whenever warranted. Our simulations confirm the expected improvements and show that the accelerated simulated tempering scheme has a much faster convergence to the target distribution than Geyer and Thompson's simulated tempering algorithm and exhibits accuracy comparable to the simulated annealing method

  19. Accelerated simulated tempering

    Li, Yaohang; Protopopescu, Vladimir A.; Gorin, Andrey

    2004-08-01

    We propose a new stochastic global optimization method by accelerating the simulated tempering scheme with random walks executed on a temperature ladder with various transition step sizes. By suitably choosing the length of the transition steps, the accelerated scheme enables the search process to execute large jumps and escape entrapment in local minima, while retaining the capability to explore local details, whenever warranted. Our simulations confirm the expected improvements and show that the accelerated simulated tempering scheme has a much faster convergence to the target distribution than Geyer and Thompson's simulated tempering algorithm and exhibits accuracy comparable to the simulated annealing method.

  20. The particle accelerator

    As the Palais de la Decouverte (in Paris) is the sole scientific vulgarization establishment in the world to operate an actual particle accelerator able to provoke different types of nuclear reactions, the author recalls some historical aspects of the concerned department since the creation of the 'Radioactivity - Atom synthesis' department in 1937. He recalls the experiments which were then performed, the installation of the particle accelerator in 1964 and its renewal. He describes what's going on in this accelerator. He gives an overview of the difficulties faced after it has been decided to move it, of the works which had to be performed, and of radiation protection measures

  1. Accelerator Toolbox for MATLAB

    This paper introduces Accelerator Toolbox (AT)--a collection of tools to model particle accelerators and beam transport lines in the MATLAB environment. At SSRL, it has become the modeling code of choice for the ongoing design and future operation of the SPEAR 3 synchrotron light source. AT was designed to take advantage of power and simplicity of MATLAB--commercially developed environment for technical computing and visualization. Many examples in this paper illustrate the advantages of the AT approach and contrast it with existing accelerator code frameworks

  2. SPS accelerating cavity

    1983-01-01

    See photo 8202397: View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  3. SPS accelerating cavity

    1983-01-01

    View towards the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138.

  4. Applicatons of accelerators

    The great diversity of possible applications of accelerators has been demonstrated in the past few years. Apart from the more familiar uses of accelerators for fundamental particle, nuclear, and solid state physics research, the applications range from microscopic trace analysis through cancer therapy to nuclear power and large volume radiation processing. Accelerators are also being used for applied research in proton radiography, radiation damage studies, laser excitation and materials analysis. The required beam properties vary from an extremely low emittance with very low beam current to megawatt beam power with a low level of beam spill. At the Chalk River Nuclear Laboratories developments are underway on applications of accelerators to nuclear fuel breeding and to cancer therapy. (author)

  5. Non-accelerator experiments

    This report discusses several topics which can be investigated without the use of accelerators. Topics covered are: (1) proton decay, (2) atmospheric neutrinos, (3) neutrino detection, (4) muons from Cygnus X-3, and (5) the double-beta decay

  6. Joint International Accelerator School

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  7. Rejuvenating CERN's Accelerators

    2004-01-01

    In the coming years and especially in 2005, CERN's accelerators are going to receive an extensive renovation programme to ensure they will perform reliably and effectively when the LHC comes into service.

  8. Vibration control in accelerators

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  9. Acceleration of Logarithmic Convergence

    Gaskin, J. G.; Ford, W. F.

    1998-01-01

    In this paper, we shall give a characterization of all monotonically decreasing sequence of positive terms, whose sum converge and then introduce a Transformation which can be used to accelerate the convergence of a large class of logarithmically convergent series.

  10. Amps particle accelerator definition study

    Sellen, J. M., Jr.

    1975-01-01

    The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

  11. Life in the Slow, Dark, Salty, Cold and Oxygen-Depleted Lane - Insights on Habitability from Lake Vida

    Murray, A.

    2014-04-01

    Ice-entrained Lake Vida brine has provided an accessible natural habitat to study life in the slow lane - where cellular growth is limited, but not extinguished. We measured in situ stable isotopic signatures of N2O, SO42-, H2, conducted experiments utilizing stable isotope geochemical tracers to detect microbial transformations and employed radioisotopically-labeled amino acid precursors to detect cellular macromolecule biosynthesis. The results indicated a dominance of abiotic processes in the brine - yet support metabolically active life through detection of nominal rates of protein biosynthesis. At the same time, the brine has posed a challenge to our understanding of ecosystem energetics. Data collected thus far suggests that the brine is isolated from surfical processes and receives no new mass or energy from above. Calculations have estimated carbon remineralization rates, which indicate that resources should be depleted to the level of small molecules perhaps supporting a methanogenic ecosystem given the amount of time since encapsulation at the temperatures recorded - yet the brine is resource-rich harboring abundant bacteria and large molecules, in addition to a complex mixture of both reduced and oxidized compounds. This has motivated explorations into alternative sources of energy such as hydrogen - which was detected at levels ~ 10 micromolar - that could be generated by brine-rock interactions and supply endogenous energy to this closed ecosystem. This cold, salty, anoxic and organically rich brine, provides insight into a new category of habitable earth ecosystems that may also give us food for thought when considering habitability of giant planet icy worlds or of icy exoplanets. However, the methods we use, and the framework of scientific inquiry applied, are limited by perception and familiarity of rates of change that are important in human time scales. The Vida-icy brine ecosystem provides a model for expansion of our understanding of

  12. A symmetrical rail accelerator

    Igenbergs, E. (Technische Univ. Muenchen, Lehrstuhl fuer Raumfahrttechnik, Richard-Wagner-Strasse 18, 8000 Muenchen 2 (DE))

    1991-01-01

    This paper reports on the symmetrical rail accelerator that has four rails, which are arranged symmetrically around the bore. The opposite rails have the same polarity and the adjacent rails the opposite polarity. In this configuration the radial force acting upon the individual rails is significantly smaller than in a conventional 2-rail configuration and a plasma armature is focussed towards the axis of the barrel. Experimental results indicate a higher efficiency compared to a conventional rail accelerator.

  13. Entropic Accelerating Universe

    Easson, Damien A.; Frampton, Paul H.; Smoot, George F.

    2010-01-01

    To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann-Lemaitre equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the entropy and temperature intrinsic to the horizon of the universe due to the information holographically stored there. Dark energy is thereby obviated and the acceleration is due to an entropic...

  14. Accelerated cyclic corrosion tests

    Prošek T.

    2016-01-01

    Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS) test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical p...

  15. CEBAF Accelerator Achievements

    In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

  16. Designing reliability into accelerators

    Future accelerators will have to provide a high degree of reliability. Quality must be designed in right from the beginning and must remain a central theme throughout the project. The problem is similar to the problems facing US industry today, and examples of the successful application of quality engineering will be given. Different aspects of an accelerator project will be addressed: Concept, Design, Motivation, Management Techniques, and Fault Diagnosis. The importance of creating and maintaining a coherent team will be stressed

  17. Advanced Accelerator Concepts

    This conference proceedings represent the results of theThird Advanced Accelerator Concepts Workshop held in PortJefferson, New York. The workshop was sponsored by the U.S.Department of Energy, the Office of Navel Research and BrookhavenNational Laboratory. The purpose was to assess new techniques forproduction of ultra-high gradient acceleration and to addressengineering issues in achieving this goal. There are eighty-onepapers collected in the proceedings and all have been abstractedfor the database

  18. Nuclear physics accelerator facilities

    Brief descriptions are given of DOE and Nuclear Physics program operated and sponsored accelerator facilities. Specific facilities covered are the Argonne Tandem/Linac Accelerator System, the Tandem/AGS Heavy Ion Facility at Brookhaven National Laboratory, the proposed Continuous Beam Accelerator at Newport News, Virginia, the Triangle Universities Nuclear Laboratory at Duke University, the Bevalac and the SuperHILAC at Lawrence Berkeley Laboratory, the 88-Inch Cyclotron at Lawrence Berkeley Laboratory, the Clinton P. Anderson Meson Physics Facility at Los Alamos National Laboratory, the Bates Linear Accelerator Center at Massachusetts Institute of Technology, the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory, the Nuclear Physics Injector at Stanford Linear Accelerator Center, the Texas A and M Cyclotrons, the Tandem/Superconducting Booster Accelerator at the University of Washington and the Tandem Van de Graaff at the A.W. Wright Nuclear Structure Laboratory of Yale University. Included are acquisition cost, research programs, program accomplishments, future directions, and operating parameters of each facility

  19. Multimegawatt cyclotron autoresonance accelerator

    Means are discussed for generation of high-quality multimegawatt gyrating electron beams using rf gyroresonant acceleration. TE111-mode cylindrical cavities in a uniform axial magnetic field have been employed for beam acceleration since 1968; such beams have more recently been employed for generation of radiation at harmonics of the gyration frequency. Use of a TE11-mode waveguide for acceleration, rather than a cavity, is discussed. It is shown that the applied magnetic field and group velocity axial tapers allow resonance to be maintained along a waveguide, but that this is impractical in a cavity. In consequence, a waveguide cyclotron autoresonance accelerator (CARA) can operate with near-100% efficiency in power transfer from rf source to beam, while cavity accelerators will, in practice, have efficiency values limited to about 40%. CARA experiments are described in which an injected beam of up to 25 A, 95 kV has had up to 7.2 MW of rf power added, with efficiencies of up to 96%. Such levels of efficiency are higher than observed previously in any fast-wave interaction, and are competitive with efficiency values in industrial linear accelerators. Scaling arguments suggest that good quality gyrating megavolt beams with peak and average powers of 100 MW and 100 kW can be produced using an advanced CARA, with applications in the generation of high-power microwaves and for possible remediation of flue gas pollutants. copyright 1996 American Institute of Physics

  20. Accelerators for America's Future

    Bai, Mei

    2016-03-01

    Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

  1. APT accelerator technology

    The proposed accelerator production of tritium (APT) project requires an accelerator that provides a cw proton beam of 100 m A at 1300 MeV. Since the majority of the technical risk of a high-current cw (continuous-wave, 100% DF) accelerator resides in the low-energy section, Los Alamos is building a 20 MeV duplicate of the accelerator front end to confirm design codes, beam performance, and demonstrate operational reliability. We report on design details of this low-energy demonstration accelerator (LEDA) and discuss the integrated design of the full accelerator for the APT plant. LEDA's proton injector is under test and has produced more than 130 mA at 75 keV. Fabrication is proceeding on a 6.7- MeV, 8-meter-long RFQ, and detailed design is underway on coupled-cavity drift-tube linac (CCDTL) structures. In addition, detailed design and technology experiments are underway on medium-beta superconducting cavities to assess the feasibility of replacing the conventional (room-temperature copper) high-energy linac with a linac made of niobium superconducting RF cavities. (author)

  2. Diffusive Shock Acceleration and Reconnection Acceleration Processes

    Zank, G. P.; Hunana, P.; Mostafavi, P.; Le Roux, J. A.; Li, Gang; Webb, G. M.; Khabarova, O.; Cummings, A.; Stone, E.; Decker, R.

    2015-12-01

    Shock waves, as shown by simulations and observations, can generate high levels of downstream vortical turbulence, including magnetic islands. We consider a combination of diffusive shock acceleration (DSA) and downstream magnetic-island-reconnection-related processes as an energization mechanism for charged particles. Observations of electron and ion distributions downstream of interplanetary shocks and the heliospheric termination shock (HTS) are frequently inconsistent with the predictions of classical DSA. We utilize a recently developed transport theory for charged particles propagating diffusively in a turbulent region filled with contracting and reconnecting plasmoids and small-scale current sheets. Particle energization associated with the anti-reconnection electric field, a consequence of magnetic island merging, and magnetic island contraction, are considered. For the former only, we find that (i) the spectrum is a hard power law in particle speed, and (ii) the downstream solution is constant. For downstream plasmoid contraction only, (i) the accelerated spectrum is a hard power law in particle speed; (ii) the particle intensity for a given energy peaks downstream of the shock, and the distance to the peak location increases with increasing particle energy, and (iii) the particle intensity amplification for a particular particle energy, f(x,c/{c}0)/f(0,c/{c}0), is not 1, as predicted by DSA, but increases with increasing particle energy. The general solution combines both the reconnection-induced electric field and plasmoid contraction. The observed energetic particle intensity profile observed by Voyager 2 downstream of the HTS appears to support a particle acceleration mechanism that combines both DSA and magnetic-island-reconnection-related processes.

  3. Accelerator business in Japan expanding

    Accelerators have become to be used increasingly in Japan in such fields as medicine, physics research and industry. This has caused stiff competition for market share by the manufacturers of accelerators. Electron beam accelerators for industrial use provide an indispensable means for adding values to products, for example, electric cables with incombustible insulators. Linear accelerators for the nondestructive inspection of nuclear components have been widely installed at equipment manufacturing plants. Active efforts have been exerted to develop small synchrotron radiation accelerators for next generation electronic industry. Cyclotrons for producing short life radioisotopes for medical diagnosis and electron beam accelerators for radiation therapy are also used routinely. The suppliers of accelerators include the companies manufacturing heavy electric machinery, heavy machinery and the engineering division of steelmakers. Accelerator physics is being formed, but universities do not yet offer the course regarding accelerators. Accelerator use in Japan and the trend of accelerator manufacturers are reported. (K.I.)

  4. Small type accelerator. Try for accelerator driven system

    Mori, Y

    2003-01-01

    FFAG (Fixed-field alternating gradient) accelerator for accelerator driven subcritical reactor, which aims to change from long-lived radioactive waste to short-lived radioactivity, is introduced. It is ring accelerator. The performance needed is proton as accelerator particle, 10MW (total) beam power, about 1GeV beam energy, >30% power efficiency and continuous beam. The feature of FFAG accelerator is constant magnetic field. PoP (Proof-of-principle)-FFAG accelerator, radial type, was run at first in Japan in 2000. The excursion is about some ten cm. In principle, beam can be injected and extracted at any place of ring. The 'multi-fish' acceleration can accelerate beams to 100% duty by repeating acceleration. 150MeV-FFAG accelerator has been started since 2001. It tried to practical use, for example, treatment of cancer. (S.Y.)

  5. A province-scale block model of Walker Lane and western Basin and Range crustal deformation constrained by GPS observations (Invited)

    Hammond, W. C.; Bormann, J.; Blewitt, G.; Kreemer, C.

    2013-12-01

    The Walker Lane in the western Great Basin of the western United States is an 800 km long and 100 km wide zone of active intracontinental transtension that absorbs ~10 mm/yr, about 20% of the Pacific/North America plate boundary relative motion. Lying west of the Sierra Nevada/Great Valley microplate (SNGV) and adjoining the Basin and Range Province to the east, deformation is predominantly shear strain overprinted with a minor component of extension. The Walker Lane responds with faulting, block rotations, structural step-overs, and has distinct and varying partitioned domains of shear and extension. Resolving these complex deformation patterns requires a long term observation strategy with a dense network of GPS stations (spacing ~20 km). The University of Nevada, Reno operates the 373 station Mobile Array of GPS for Nevada transtension (MAGNET) semi-continuous network that supplements coverage by other networks such as EarthScope's Plate Boundary Observatory, which alone has insufficient density to resolve the deformation patterns. Uniform processing of data from these GPS mega-networks provides a synoptic view and new insights into the kinematics and mechanics of Walker Lane tectonics. We present velocities for thousands of stations with time series between 3 to 17 years in duration aligned to our new GPS-based North America fixed reference frame NA12. The velocity field shows a rate budget across the southern Walker Lane of ~10 mm/yr, decreasing northward to ~7 mm/yr at the latitude of the Mohawk Valley and Pyramid Lake. We model the data with a new block model that estimates rotations and slip rates of known active faults between the Mojave Desert and northern Nevada and northeast California. The density of active faults in the region requires including a relatively large number of blocks in the model to accurately estimate deformation patterns. With 49 blocks, our the model captures structural detail not represented in previous province-scale models, and

  6. Analysis of Drivers' Lane Changing Decision-making Mechanism and Its Visual Characteristics%驾驶人换道决策机制及视觉特性分析

    彭金栓; 付锐; 郭应时

    2013-01-01

    In order to analyze drivers' behavior characteristics before lane changing, and extract the characterization parameters reflecting the lane changing intent, experiments in real environment were designed. Based on drivers' perception of external information and judgment, the formation mechanism of lane changing decision making was analyzed in detail. According to drivers' fixation characteristics on rearview mirror, lane changing intent time window was determined, characterization parameters reflecting drivers' lane changing intent were extracted subsequently. The results show that lane-changing decision is composed of information perception and three judgment-decision processes, that drivers' lane changing intent time window is about 5 s, and that fixation frequencies on rearview mirrors and blind areas, as well as fixation duration and proba-biliies on related lanes could effectively characterize drivers' lane changing intent.%为透析换道前驾驶人行为机理,提取可以体现驾驶人换道意图的表征参数,设计真实道路条件下的实车试验,对换道决策机制进行深入研究.基于驾驶人对外界信息的感知特性、判断决策等,分析驾驶人车道变换决策的形成机理.依据换道前驾驶人对后视镜的注视特性确定换道意图时窗,进一步提取驾驶人车道变换意图表征指标.分析表明,换道决策由信息感知及3个判断决策过程复合而成,驾驶人换道意图表征时窗约为5 s;后视镜及视野盲区注视频次,当前车道与目标车道的注视时间及注视概率等指标都可以用来有效表征驾驶人的车道变换意图.

  7. High energy plasma accelerators

    Colinear intense laser beams ω0, kappa0 and ω1, kappa1 shone on a plasma with frequency separation equal to the electron plasma frequency ω/sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ω/sub pe//e of the order of 1GeV/cm for a plasma density of 1018 cm-3 through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed

  8. Relativistic heavy ion accelerators

    There is a growing interest in the scientific community in the use of accelerators to produce relativistic heavy ion beams for a number of purposes. It now appears that relativistic heavy ion collisions may provide an opportunity to study nuclear matter far from equilibrium density, pressure, and temperature. Heavy ion beams can also be used as simulated cosmic rays for astrophysical research and in planning space probes. At present the only relativistic heavy ion accelerator is the Belvalac at LBL. It has been devoted to this use since 1974. The operating experience and capabilities of this machine are reviewed as well as present and planned experimental programs. Designs of accelerators for relativistic heavy ions are discussed. A number of considerations will cause a machine to differ from a proton machine if optimally designed for heavy ion acceleration. A possible set of parameters is presented for an accelerator to produce intense beams of mass 10 to 200 ions, at energies up to 10 GeV/amu

  9. Dielectric laser accelerators

    England, R. Joel; Noble, Robert J.; Bane, Karl; Dowell, David H.; Ng, Cho-Kuen; Spencer, James E.; Tantawi, Sami; Wu, Ziran; Byer, Robert L.; Peralta, Edgar; Soong, Ken; Chang, Chia-Ming; Montazeri, Behnam; Wolf, Stephen J.; Cowan, Benjamin; Dawson, Jay; Gai, Wei; Hommelhoff, Peter; Huang, Yen-Chieh; Jing, Chunguang; McGuinness, Christopher; Palmer, Robert B.; Naranjo, Brian; Rosenzweig, James; Travish, Gil; Mizrahi, Amit; Schachter, Levi; Sears, Christopher; Werner, Gregory R.; Yoder, Rodney B.

    2014-10-01

    The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the GV /m regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

  10. Accelerating nondiffracting beams

    Yan, Shaohui; Li, Manman; Yao, Baoli, E-mail: yaobl@opt.ac.cn; Yu, Xianghua; Lei, Ming; Dan, Dan; Yang, Yanlong; Min, Junwei; Peng, Tong

    2015-06-05

    We present a set of beams which combine the properties of accelerating beams and (conventional) diffraction-free beams. These beams can travel along a desired trajectory while keeping an approximately invariant transverse profile, which may be (higher-order) Bessel-, Mathieu- or parabolic-nondiffracting-like beams, depending on the initial complex amplitude distribution. A possible application of these beams presented here may be found in optical trapping field. For example, a higher-order Bessel-like beam, which has a hollow (transverse) pattern, is suitable for guiding low-refractive-index or metal particles along a curve. - Highlights: • A set of beams having arbitrary trajectories of accelerating and nondiffracting behaviors are generalized and presented. • Bessel-like accelerating beams are generalized to the higher-order (hollow) version. • Mathieu-like accelerating beams and parabolic-nondiffracting-like accelerating beams are presented. • A possible application of these beams may be found in optical trapping and guiding of particles.

  11. Mixed logit model-based driver injury severity investigations in single- and multi-vehicle crashes on rural two-lane highways.

    Wu, Qiong; Chen, Feng; Zhang, Guohui; Liu, Xiaoyue Cathy; Wang, Hua; Bogus, Susan M

    2014-11-01

    Crashes occurring on rural two-lane highways are more likely to result in severe driver incapacitating injuries and fatalities. In this study, mixed logit models are developed to analyze driver injury severities in single-vehicle (SV) and multi-vehicle (MV) crashes on rural two-lane highways in New Mexico from 2010 to 2011. A series of significant contributing factors in terms of driver behavior, weather conditions, environmental characteristics, roadway geometric features and traffic compositions, are identified and their impacts on injury severities are quantified for these two types of crashes, respectively. Elasticity analyses and transferability tests were conducted to better understand the models' specification and generality. The research findings indicate that there are significant differences in causal attributes determining driver injury severities between SV and MV crashes. For example, more severe driver injuries and fatalities can be observed in MV crashes when motorcycles or trucks are involved. Dark lighting conditions and dusty weather conditions are found to significantly increase MV crash injury severities. However, SV crashes demonstrate different characteristics influencing driver injury severities. For example, the probability of having severe injury outcomes is higher when vans are identified in SV crashes. Drivers' overtaking actions will significantly increase SV crash injury severities. Although some common attributes, such as alcohol impaired driving, are significant in both SV and MV crash severity models, their effects on different injury outcomes vary substantially. This study provides a better understanding of similarities and differences in significant contributing factors and their impacts on driver injury severities between SV and MV crashes on rural two-lane highways. It is also helpful to develop cost-effective solutions or appropriate injury prevention strategies for rural SV and MV crashes. PMID:25016459

  12. 基于Android平台的车道线检测系统设计%A method to implementation of lane detection under Android system

    黄惠迪; 官洪运; 邓昶; 薛节

    2015-01-01

    Vision-based lane detection methods mainly adopt the Hough transform for straight-line fitting, but there are computationally intensive, slow operation and other issues of the method. In this paper, taken structured roads feature into consideration, a new algorithm to identify high complexity of small and unsupervised adaptive linear classifier on the Android platform to achieve the lane detection and real-time tracking. Because of the portability of Android mobile terminals, we will use OpenCV development of the lane detection and tracking system ported to the Android platform, making intelligent driver assistance more flexible, while extending the application fields of the Android platform.%在以图象处理为基础的车道线检测中,主要以采用Hough变换直线拟合等方法进行,但该方法存在计算量大,运算速度慢等问题。本文针对该问题,提出一种在结构化道路中识别效率高的非监督自适应直线分类器。同时运用OpenCV提供库进行开发,在 Android平台上实现了车道线检测与实时跟踪系统。经过实验表明在Android平台上,本文提出的车道线检测系统相对于传统方法每秒处理图像帧数fps数倍增加,有效的提升了辅助安全系统的功能。

  13. Accelerators for atomic energy research

    The research and educational activities accomplished using accelerators for atomic energy research were studied. The studied items are research subjects, facility operation, the number of master theses and doctor theses on atomic energy research using accelerators and the future role of accelerators in atomic energy research. The strategy for promotion of the accelerator facility for atomic energy research is discussed. (author)

  14. Plasma-based accelerator structures

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas

  15. A STUDY OF THE DYNAMIC PARAMETERS INFLUENCE OVER THE BEHAVIOR OF THE TWO-SECTION ARTICULATED VEHICLE DURING THE LANE CHANGE MANOEUVRE

    Rusi RUSEV

    2016-03-01

    Full Text Available The course stability and the steerability of the two-section wheeled vehicle at high velocities during the lane change manoeuvre are studied in this paper. Mechanic-mathematical model is developed, on which base simulation programmes are elaborated. Simulation studies of the course stability at different velocities depend on some constructive and exploitation factors are made by these models. Based on the simulation results an idea for an algorithm and a semi-active control system of the resistance in the pulling-supporting device is proposed.

  16. Uniform Acceleration in General Relativity

    Friedman, Yaakov

    2016-01-01

    We extend de la Fuente and Romero's defining equation for uniform acceleration in a general curved spacetime from linear acceleration to the full Lorentz covariant uniform acceleration. In a flat spacetime background, we have explicit solutions. We use generalized Fermi-Walker transport to parallel transport the Frenet basis along the trajectory. In flat spacetime, we obtain velocity and acceleration transformations from a uniformly accelerated system to an inertial system. We obtain the time dilation between accelerated clocks. We apply our acceleration transformations to the motion of a charged particle in a constant electromagnetic field and recover the Lorentz-Abraham-Dirac equation.

  17. Superconducting Accelerator Magnets

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  18. Entropic Accelerating Universe

    Easson, Damien A; Smoot, George F

    2010-01-01

    To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann-Lema\\^{i}tre equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the temperature intrinsic to the information holographically stored on the screen which is the surface of the universe. Dark energy is thereby obviated and the acceleration is due to an entropic force naturally arising from the information storage on a surface screen. We consider an additional quantitative approach based upon the entropy and surface terms usually neglected in General Relativity and show that this leads to the entropic accelerating universe.

  19. Superconducting accelerator magnet design

    Superconducting dipoles, quadrupoles and correction magnets are necessary to achieve the high magnetic fields required for big accelerators presently in construction or in the design phase. Different designs of superconducting accelerator magnets are described and the designs chosen at the big accelerator laboratories are presented. The most frequently used cosθ coil configuration is discussed in detail. Approaches for calculating the magnetic field quality including coil end fields are presented. Design details of the cables, coils, mechanical structures, yokes, helium vessels and cryostats including thermal radiation shields and support structures used in superconducting magnets are given. Necessary material properties are mentioned. Finally, the main results of magnetic field measurements and quench statistics are presented. (orig.)

  20. Accelerators for therapy

    In the past decades circular and linear electron accelerators have been developed for clinical use in radiation therapy of tumors with the aim of achieving a high radiation dose in the tumor and as low as possible dose in the adjacent normal tissues. Today about one thousand accelerators are in medical use throughout the world and many hundred thousand patients are treated every day with accelerator-produced radiation. There exists, however, a large number of patients who cannot be treated satisfactorily in this way. New types of radiations such as neutrons, negative pions, protons and heavy ions were therefore tested recently. The clinical experience with these radiations and with new types of treatment procedures indicate that in future the use of a scanning beam of high energy protons might be optimal for the treatment of tumors. (orig.)

  1. Microelectromechanical acceleration-sensing apparatus

    Lee, Robb M.; Shul, Randy J.; Polosky, Marc A.; Hoke, Darren A.; Vernon, George E.

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  2. Studies of accelerated compact toruses

    In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa -2, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  3. CERN: Accelerator school

    Full text: Jyvaskyla, a university town in central Finland, was the setting for last year's General Accelerator School organized by the CERN Accelerator School. Well over a hundred students - more than for some time - followed two weeks of lectures on a broad spectrum of accelerator topics, the first step en route to becoming the designers, builders and operators of the surprisingly large number of, accelerators of all kinds either built or planned throughout Europe and further afield. This was the fifth such school organized by CAS in a biennial cycle which alternates this introductory level with more advanced tuition. The next, advanced, school will be from 20 October - 1 November, hosted by Athens University on the Greek Island of Rhodes. (Application details will become available in Spring but would-be participants should already reserve the dates.) After Finland, the CAS caravan moved to Benalmadena near Malaga in Spain where, together with Seville University, they organized one of the joint US-CERN schools held every two years and focusing on frontier accelerator topics. This time the subject was electron-positron factories - machines for high luminosity experiments in phi, tau-charm, beauty and Z physics. Experts from both sides of the Atlantic and from Japan shared their knowledge with an equally representative audience and probed the many intensity related phenomena which must be mastered to reach design performance. A number of these topics will receive extended coverage in the next specialist CAS School which is a repeat - by public demand - of the highly successful radiofrequency course held in Oxford in 1991. This school will be in Capri, Italy, with the support of the University of Naples from 29 April to 5 May. Details and application forms are now available by e-mail (CASRF@CERNVM.CERN.CH), by fax (+41 22 7824836) or from Suzanne von Wartburg, CERN Accelerator School, 1211 Geneva 23, Switzerland

  4. Nuclear Physics accelerator facilities

    The Nuclear Physics program requires the existence and effective operation of large and complex accelerator facilities. These facilities provide the variety of projectile beams upon which virtually all experimental nuclear research depends. Their capability determine which experiments can be performed and which cannot. Seven existing accelerator facilities are operated by the Nuclear Physics program as national facilities. These are made available to all the Nation's scientists on the basis of scientific merit and technical feasibility of proposals. The national facilities are the Clinton P. Anderson Meson Physics Facility (LAMPF) at Los Alamos National Laboratory; the Bates Linear Accelerator Center at Massachusetts Institute of Technology; the Bevalac at Lawrence Berkeley Laboratory; the Tandem/AGS Heavy Ion Facility at Brookhaven National Laboratory; the ATLAS facility at Argonne National Laboratory; the 88-Inch Cyclotron at Lawrence Berkeley Laboratory; the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory. The Nuclear Physics Injector at the Stanford Linear Accelerator Center (SLAC) enables the SLAC facility to provide a limited amount of beam time for nuclear physics research on the same basis as the other national facilities. To complement the national facilities, the Nuclear Physics program supports on-campus accelerators at Duke University, Texas A and M University, the University of Washington, and Yale University. The facility at Duke University, called the Triangle Universities Nuclear Laboratory (TUNL), is jointly staffed by Duke University, North Carolina State University, and the University of North Carolina. These accelerators are operated primarily for the research use of the local university faculty, junior scientists, and graduate students

  5. Constraints from GPS on Block Kinematics of the Transition between the Southern Walker Lane and the Basin and Range Province

    Jha, S.; Hammond, W. C.; Kreemer, C.; Blewitt, G.

    2008-12-01

    The southern Walker Lane (SWL) is a part of the Eastern California Shear Zone that lies north of the Mojave region, bounded by the Garlock Fault to the south, the Sierra Nevada to the west, the Basin and Range to the east and by Mono Lake to the north. The region includes many northwest striking right-lateral strike slip and sub-parallel normal faults (e.g. Death Valley/Furnace Creek, Fish Lake Valley, Owens Valley), which together accommodate ~25% of the Pacific/North American relative motion. For many of these faults, and the system as a whole, there appears to be a discrepancy between geodetically and geologically inferred fault slip rates. Since the installation of the EarthScope Plate Boundary Observatory (PBO), and the Nevada Earthquake Response Network (NEARNET) of the University of Nevada, Reno, many recently obtained high- precision GPS data are now available to place improved constraints on the pattern and rates of crustal deformation of this region. In this study we use a block modeling methodology to estimate block motions and fault slip rates from GPS velocities of PBO, NEARNET and BARGEN continuous sites. Time series were obtained from raw RINEX data that we processed using the GIPSY-OASIS II software from the Jet Propulsion Laboratory together with the Ambizap software for ambiguity resolution. We have additionally included earlier published campaign-style velocities, in those areas where we do not have better coverage from other continuous/semi-continuous networks. Geologic slip rates have been obtained from the published literature. We solve for the motion of blocks using the GPS velocities that have been adjusted based on the viscoelastic modeling to estimate long term motion. To evaluate the consistency between the geologic and geodetic data, we compare long-term fault slip to slip rates inferred from geodetic results obtained over Basin and Range. The preliminary results obtained from the block model indicate significant slip at the easternmost

  6. Intermittent Sea Level Acceleration

    Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Spada, G.; Dipartimento di Scienze di Base e Fondamenti, Università di Urbino Carlo Bo, Urbino

    2013-01-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea{level acceleration for the last 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, con firm the existence of a global sea level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0:01 mm/yr2. However, di fferently from previous studies, we discuss how change points or ...

  7. Acceleration of polarized particles

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  8. Space charge wave accelerators

    We present an account of experimental observations showing control of the wave phase velocity for a slow wave, measurements of the wave electric field, and indicate how these results might apply to an ion accelerator. An interesting and new possibility is also indicated, namely the use of fast waves for electron accelerators. In this case preliminary estimates indicate that comparable field gradients to those already obtained in the slow wave scheme should be obtainable in fast waves and that these field gradients can be maintained at phase velocities close to the speed of light. (orig./HSI)

  9. High intensity hadron accelerators

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics

  10. Seismic surveying and accelerators

    The paper deals with an investigation into the impact of earth vibrations on charged particle beams in modern colliders. It is ascertained that the displacement of accelerator magnetic elements from the perfect position results in the excitation of betatron oscillations and distortion of particle orbit position. The results of experimental investigations into seismic noises are presented for ASR, SSC, DESY and KEK. The rms orbit displacement in accelerators is estimated relying on the law of earth diffusion motion, according to which the variance of relative displacements is proportional to the distance between these points and time of observation. 6 refs., 3 figs., 2 tabs

  11. Interfacing to accelerator instrumentation

    As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed

  12. Left lane road electrification

    Llanes-Estrada, Felipe J

    2010-01-01

    We propose the partial electrification of multilane motorways in suburban areas as a practical alternative in order to reduce the weight and price of electrically-powered automobiles. These could then be supplied energy en-route, thus significantly reducing the weight and cost of vehicle-mounted batteries. Our theoretical study is based on the circumstances of Madrid (Spain), a six million inhabitant region, but should be easily adaptable to other metropolitan areas.

  13. Cherry Lane Movies

    2004-01-01

    Directed: Dayyan EngStarring: Gong Beibei, Wu Chao, Li Yixiang and Zhou KuiProduced: 2001, 11 minutes A woman drives a bus along deserted country roads, and she picks up a young man alongthe way. Although the man tries to talk to the driver, she's not interested. Eventually, two robbersclimb into the bus, steal the passengers' money, and drag the driver behind some bushes,where they rape her. Only one passenger—the young man—tries to protect her. The remaining passengers sit

  14. Cherry Lane Movies

    2004-01-01

    Friday & Saturday,Sept.10-11,8 pmMaster of Everything自娱自乐Director:Xin LeeStarring:John Lone,Coco Lee,Tao HongProduced:2004,97 minutes Based an true events, "Master of Everything" mixes two of the most popularfilm genres in Asia-comedy and kung-fu.

  15. Cherry Lane Movies

    2004-01-01

    Friday and Saturday, July 2-3, 8pmMama’s Go/aJin Wa Wa 金娃娃Director: Joanne Cheng Produced: 2003, 92 minutesFilmed in the historical town of Lijiang, "Mama’s Gold" tells the moving story of one woman (Mama) and her 300 once destitutechildren, ranging in age from 2 to 18 and originating from 14 different ethnic groups, all survivors of devastating earthquakes and poverty stricken regions of rural China.Based on the conflict between Mama and her American donor who took Mama to Chinese court, the film reveals the complex multi-cultural worlds of both children and adults who unfortunately shared little in common. Told through the filmmaker ’s point of view, the film examines life in the orphanage and visits the Children’s mountain homes. The film captures the emotional journey of Mama and her children who desperately need each other.Cheng also directed, wrote, produced the award-winning China Gold Rush, an inter-cultural documentary on changing lives in millennium China. Cheng went to college in the

  16. SPS accelerating cavity

    CERN PhotoLab

    1981-01-01

    One of the SPS accelerating cavities (200 MHz, travelling wave structure). The power that is fed into the upstream end of the cavity is extracted at the downstream end and sent into a dump load. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8011289, 8302397.

  17. SPS accelerating cavity

    1983-01-01

    See photo 8302397: View from the downstream end of one of the SPS accelerating cavities (200 MHz, travelling wave structure). See 7603195 and 8011289 for more details, 7411032 for the travelling wave structure, and also 8104138. Giacomo Primadei stands on the left.

  18. Hamburg Accelerator Conference

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). A natural highlight was the recent commissioning success of the HERA electron-proton collider at Hamburg's DESY Laboratory and its first high energy electron-proton collision data. This gave the meeting the feel of a family event celebrating a newborn

  19. Heavy ion accelerator GANIL

    This article presents GANIL, a large national heavy ion accelerator. The broad problems of nuclear physics, atomic physics, astrophysics and physics of condensed media which can be approached and studied with this machine are discussed first, after which the final construction project is described. The project comprises a circular injector, a separated sector cyclotron up beam stripper, and a second separated cyclotron downstream

  20. Dissociation by acceleration

    Peeters, K.; Zamaklar, M.

    2008-01-01

    We show that mesons, described using rotating relativistic strings in a holographic setup, undergo dissociation when their acceleration 'a' exceeds a value which scales with the angular momentum 'J' as a_max ~ \\sqrt{T_s/J}, where 'T_s' is the string tension.

  1. Dissociation by acceleration

    2007-01-01

    We show that mesons, described using rotating relativistic strings in a holographic setup, undergo dissociation when their acceleration 'a' exceeds a value which scales with the angular momentum 'J' as a_max ~ \\sqrt{T_s/J}, where 'T_s' is the string tension.

  2. The CERN accelerator complex

    De Melis, Cinzia

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  3. SPS accelerating cavity

    1980-01-01

    One of the SPS acceleration cavities (200 MHz, travelling wave structure). On the ceiling one sees the coaxial transmission line which feeds the power from the amplifier, located in a surface building above, to the upstream end of the cavity. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8104138, 8302397.

  4. Accelerators in the sky

    The author surveys the large body of evidence showing that there are very efficient mechanisms capable of accelerating particles to high energies under very different astrophysical conditions. The circumstances whereby huge amounts of relativistic and ultrarelativistic particles such as one finds in a) cosmic rays, b) supernova remnants and c) radio galaxies and quasars are produced are considered. (Auth.)

  5. Prospects for Accelerator Technology

    Todd, Alan

    2011-02-01

    Accelerator technology today is a greater than US$5 billion per annum business. Development of higher-performance technology with improved reliability that delivers reduced system size and life cycle cost is expected to significantly increase the total accelerator technology market and open up new application sales. Potential future directions are identified and pitfalls in new market penetration are considered. Both of the present big market segments, medical radiation therapy units and semiconductor ion implanters, are approaching the "maturity" phase of their product cycles, where incremental development rather than paradigm shifts is the norm, but they should continue to dominate commercial sales for some time. It is anticipated that large discovery-science accelerators will continue to provide a specialty market beset by the unpredictable cycles resulting from the scale of the projects themselves, coupled with external political and economic drivers. Although fraught with differing market entry difficulties, the security and environmental markets, together with new, as yet unrealized, industrial material processing applications, are expected to provide the bulk of future commercial accelerator technology growth.

  6. Radioisotope Dating with Accelerators.

    Muller, Richard A.

    1979-01-01

    Explains a new method of detecting radioactive isotopes by counting their accelerated ions rather than the atoms that decay during the counting period. This method increases the sensitivity by several orders of magnitude, and allows one to find the ages of much older and smaller samples. (GA)

  7. Accelerating News Issue 5

    Szeberenyi, A

    2013-01-01

    In this spring issue, we look at developments towards higher luminosity and higher energy colliders. We report on the technology developed for the remote powering of the LHC magnets and studies of diagnostics based on higher order mode port signals. We also inform you about the main outcome of the TIARA survey on market needs for accelerator scientists.

  8. The CERN Accelerator School

    2016-01-01

      Introduction to accelerator physics This course will take place in Istanbul, Turkey, from 18 to 30 September 2016. It is now open for registration, and further information can be found here: http://cas.web.cern.ch/cas/Turkey-2016/Turkey-advert.html

  9. The CERN Accelerator School

    2016-01-01

    Introduction to accelerator physics This course will take place in Budapest, Hungary, from 2 to 14 October 2016. It is now open for registration and further information can be found at: http://cas.web.cern.ch/cas/Hungary2016/Hungary-advert.html and http://indico.cern.ch/event/532397/.

  10. The CERN accelerator complex

    Haffner, Julie

    2013-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  11. The CERN accelerator complex

    Christiane Lefèvre

    2008-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  12. Superconducting traveling wave accelerators

    This note considers the applicability of superconductivity to traveling wave accelerators. Unlike CW operation of a superconducting standing wave or circulating wave accelerator section, which requires improvement factors (superconductor conductivity divided by copper conductivity) of about 106 in order to be of practical use, a SUperconducting TRaveling wave Accelerator, SUTRA, operating in the pulsed mode requires improvement factors as low as about 103, which are attainable with niobium or lead at 4.2K, the temperature of liquid helium at atmospheric pressure. Changing from a copper traveling wave accelerator to SUTRA achieves the following. (1) For a given gradient SUTRA reduces the peak and average power requirements typically by a factor of 2. (2) SUTRA reduces the peak power still further because it enables us to increase the filling time and thus trade pulse width for gradient. (3) SUTRA makes possible a reasonably long section at higher frequencies. (4) SUTRA makes possible recirculation without additional rf average power. 8 references, 6 figures, 1 table

  13. Accelerating Fermionic Molecular Dynamics

    Clark, M. A.; Kennedy, A. D.

    2004-01-01

    We consider how to accelerate fermionic molecular dynamics algorithms by introducing n pseudofermion fields coupled with the nth root of the fermionic kernel. This reduces the maximum pseudofermionic force, and thus allows a larger molecular dynamics integration step size without hitting an instability in the integrator.

  14. The Bevalac accelerator

    Presented are the characteristics of the Bevatron and SuperHilac heavy ion accelerators in a very general manner. Some aspects of their application in the field of biological medicine and some of the interesting results obtained in experiments on nuclear physics are mentioned. (Author). 20 refs, 2 figs, 2 tabs

  15. Identification of column edges of DNA fragments by using K-means clustering and mean algorithm on lane histograms of DNA agarose gel electrophoresis images

    Turan, Muhammed K.; Sehirli, Eftal; Elen, Abdullah; Karas, Ismail R.

    2015-07-01

    Gel electrophoresis (GE) is one of the most used method to separate DNA, RNA, protein molecules according to size, weight and quantity parameters in many areas such as genetics, molecular biology, biochemistry, microbiology. The main way to separate each molecule is to find borders of each molecule fragment. This paper presents a software application that show columns edges of DNA fragments in 3 steps. In the first step the application obtains lane histograms of agarose gel electrophoresis images by doing projection based on x-axis. In the second step, it utilizes k-means clustering algorithm to classify point values of lane histogram such as left side values, right side values and undesired values. In the third step, column edges of DNA fragments is shown by using mean algorithm and mathematical processes to separate DNA fragments from the background in a fully automated way. In addition to this, the application presents locations of DNA fragments and how many DNA fragments exist on images captured by a scientific camera.

  16. Clustering of velocities in a GPS network spanning the Sierra Nevada Block, the northern Walker Lane Belt, and the Central Nevada Seismic Belt, California-Nevada

    Savage, James C.; Simpson, Robert W.

    2013-01-01

    The deformation across the Sierra Nevada Block, the Walker Lane Belt, and the Central Nevada Seismic Belt (CNSB) between 38.5°N and 40.5°N has been analyzed by clustering GPS velocities to identify coherent blocks. Cluster analysis determines the number of clusters required and assigns the GPS stations to the proper clusters. The clusters are shown on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that GPS station belongs. Fault systems that separate the clusters are readily identified on such a map. Four significant clusters are identified. Those clusters are strips separated by (from west to east) the Mohawk Valley-Genoa fault system, the Pyramid Lake-Wassuk fault system, and the Central Nevada Seismic Belt. The strain rates within the westernmost three clusters approximate simple right-lateral shear (~13 nstrain/a) across vertical planes roughly parallel to the cluster boundaries. Clustering does not recognize the longitudinal segmentation of the Walker Lane Belt into domains dominated by either northwesterly trending, right-lateral faults or northeasterly trending, left-lateral faults.

  17. Mixed traffic flow model considering illegal lane-changing behavior: Simulations in the framework of Kerner’s three-phase theory

    Hu, Xiaojian; Wang, Wei; Yang, Haifei

    2012-11-01

    This paper studies the mixed motorized vehicle (m-vehicle) and non-motorized vehicle (nm-vehicle) traffic flow in the m-vehicle lane. We study the formation mechanism of the nm-vehicle illegal lane-changing behavior (NILB) by considering the overtaking motivation and the traffic safety awareness. In the framework of Kerner’s three-phase theory, we propose a model for the mixed traffic flow by introducing a new set of rules. A series of simulations are carried out in order to reveal the formation, travel process and influence of the mixed traffic flow. The simulation results show that the proposed model can be used to study not only the travel characteristic of the mixed traffic flow, but also some complex traffic problems such as traffic breakdown, moving synchronized flow pattern (MSP) and moving jam. Moreover, the results illustrate that the proposed model reflects the phenomenon of the mixed flow and the influence of the MSP caused by the NILB, which is consistent with the actual traffic system, and thus this work is helpful for the management of the mixed traffic flow.

  18. 自然驾驶条件下驾驶人换道行为实时预测%Real-time prediction of lane-changing behaviors under naturalistic driving condtions

    彭金栓; 付锐; 郭应时

    2015-01-01

    为降低车道变换的风险性,提出一种基于驾驶人视觉特性与车辆运动状态预测车道变换行为的方法. 应用视觉追踪系统、毫米波雷达等仪器设备,进行了真实环境下的实车驾驶试验. 基于换道前驾驶人后视镜注视特性确定换道意图时窗大小为5 s,构建换道行为预测的表征指标体系. 设计BP神经网络结构,构建换道行为预测模型. 结果表明:模型可以至少提前1.5 s预测驾驶人的换道行为,且预测精度达到95.58%. 与基于转向灯状态预测驾驶人换道行为相比,其预测精度及时序特性均有显著提升,证明了预测指标及预测方法的有效性.%To reduce the risk of lane changing behaviors, based upon drivers' visual characteristics and vehicle motion states, a method for lane change prediction is proposed. By using visual tracking system, millimeter-wave radar and so on, the research group conducts experiments under real road environment. Based on drivers' fixation characteristics of the rearview mirrors before lane change occurs, lane changing intent time window is determined as 5 s, the characteristic index for predict lane changing behavior is further built. By designing BP neural network, the lane change prediction model is constructed. Results show that the model may predict drivers ' lane changing behavior for at least 1.5 s in advance, and the prediction accuracy can reach 95.58%. As compared to predict lane change behavior via turn signals, the prediction accuracy and time series characteristics are both improved remarkably, thus verifying the effectiveness of the predictive index and method.

  19. Nonlinear dynamics in particle accelerators

    Dilão, Rui

    1996-01-01

    This book is an introductory course to accelerator physics at the level of graduate students. It has been written for a large audience which includes users of accelerator facilities, accelerator physicists and engineers, and undergraduates aiming to learn the basic principles of construction, operation and applications of accelerators.The new concepts of dynamical systems developed in the last twenty years give the theoretical setting to analyse the stability of particle beams in accelerator. In this book a common language to both accelerator physics and dynamical systems is integrated and dev

  20. Accelerator mass spectrometry programme at Mumbai pelletron accelerator facility

    The Accelerator Mass Spectrometry (AMS) programme and the related developments based on the Mumbai Pelletron accelerator are described. The initial results of the measurement of the ratio, 36Cl / Cl in water samples are presented. (author)

  1. Internal structure of spiral arms traced with [C II]: Unraveling the warm ionized medium, H I, and molecular emission lanes

    Velusamy, T.; Langer, W. D.; Goldsmith, P. F.; Pineda, J. L.

    2015-06-01

    Context. The spiral arm tangencies are ideal lines of sight in which to determine the distribution of interstellar gas components in the spiral arms and study the influence of spiral density waves on the interarm gas in the Milky Way. [C II] emission in the tangencies delineates the warm ionized component and the photon-dominated regions and is thus an important probe of spiral arm structure and dynamics. Aims: We aim to use [C II], H I, and 12CO spectral line maps of the Crux, Norma, and Perseus tangencies to analyze the internal structure of the spiral arms in different gas layers. Methods: We used [C II] l-V maps along with those for H I and 12CO to derive the average spectral line intensity profiles over the longitudinal range of each tangency. Using the VLSR of the emission features, we located the [C II], H I, and 12CO emissions along a cross cut of the spiral arm. We used the [C II] velocity profile to identify the compressed warm ionized medium (WIM) in the spiral arm. Results: We present a large-scale (~15°) position-velocity map of the Galactic plane in [C II] from l = 326.6° to 341.4° observed with Herschel HIFI. In the spectral line profiles at the tangencies, [C II] has two emission peaks, one associated with the compressed WIM and the other the molecular gas photon-dominated regions. When represented as a cut across the inner to outer edge of the spiral arm, the [C II]-WIM peak appears closest to the inner edge while 12CO and [C II] associated with molecular gas are at the outermost edge. H I has broader emission with an intermediate peak located nearer to that of 12CO. Conclusions: The velocity-resolved spectral line data of the spiral arm tangencies unravel the internal structure in the arms locating the emission lanes within them. We interpret the excess [C II] near the tangent velocities as shock compression of the WIM induced by the spiral density waves and as the innermost edge of spiral arms. For the Norma and Perseus arms, we estimate

  2. Geodetic vs. Geologic Measures of Fault Slip Rates in the Northern Walker Lane, Basin and Range Province, Western United States

    Hammond, W. C.; Kreemer, C.; Blewitt, G.

    2008-05-01

    Quantifying faults slip rates and styles is an important objective in the study of crustal deformation. Fault slip rates are used to quantify seismic hazard associated with active faults, and are an important input into the U.S.G.S. seismic hazard maps. However, when multiple types of data (e.g. geologic, seismic and geodetic) are used to measure slip rates, results from the different techniques can be corroborative, complementary, or in direct conflict. Geologic methods provide some of the only constraints on slip rates of individual faults over hundreds to tens of thousands of years, time scales that are significant with respect to observed deformation patterns, and likely representative of modern hazard. On the other hand geodetic measurements provide strong constraints on the medium to long spatial wavelength (>50 km) budgets of deformation, and on geographic changes in deformation style, and have the potential to provide geographically complete measurements of surface deformation. However, geodetic measurements can be influenced by earthquake cycle effects, e.g. owing to interseismic fault locking and postseismic relaxation, which limit their ability to resolve individual slip rates, especially in complex systems with many closely spaced faults. The northern Walker Lane (NWL), in the western Basin and Range Province (BRP) of the United States, is an example of a complex system of dextral, normal and sinestral faults that work together to accommodate approximately 10 mm/yr of relative motion between the Sierra Nevada/Great Valley block and the central part of the BRP. To exploit the strengths of each dataset, we have built a detailed model of NWL crustal blocks and are using geodetic and geologic data to resolve patterns of crustal deformation. We use a block modeling technique that incorporates the strengths of both targeted geologic investigations of slip rates on individual faults and longer wavelength constraints offered by GPS geodesy. To constrain these

  3. accelerating cavity from LEP

    This is an accelerating cavity from LEP, with a layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  4. Review of accelerator instrumentation

    Some of the problems associated with the monitoring of accelerator beams, particularly storage rings' beams, are reviewed along with their most common solutions. The various electrode structures used for the measurement of beam current, beam position, and the detection of the bunches' transverse oscillations, yield pulses with sub-nanosecond widths. The electronics for the processing of these short pulses involves wide band techniques and circuits usually not readily available from industry or the integrated circuit market: passive or active, successive integrations, linear gating, sample-and-hold circuits with nanosecond acquisition time, etc. This report also presents the work performed recently for monitoring the ultrashort beams of colliding linear accelerators or single-pass colliders. To minimize the beam emittance, the beam position must be measured with a high resolution, and digitized on a pulse-to-pulse basis. Experimental results obtained with the Stanford two-mile Linac single bunches are included

  5. Hardware Accelerated Simulated Radiography

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-04-12

    We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists.

  6. Review of ion accelerators

    The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here

  7. RFQ accelerator development

    Radio frequency quadrupole (RFQ) accelerators have established themselves as highly efficient and potential tools for delivering intense beams of the order of 100 mA or more. They are being employed as injectors to high energy machines used for basic sciences, spallation neutron sources, fusion devices and accelerator breeders. They have also made their mark as neutron generators, ion implanters, x-ray generators, etc. Realising the importance of this programme, Bhabha Atomic Research Centre initiated a totally indigenous effort to develop RFQs for the light as well as heavy ion beams. A low power RFQ for the proton and deuteron beams is already in the final phase of commissioning. (author). 30 refs., 14 figs., 2 tabs

  8. Accelerator research studies

    This progress report for the Accelerator Research Studies program at the University of Maryland covers the second year (June 1, 1989 to May 31, 1990) of the current three-year contract period from June 1, 1988 to May 31, 1991, funded by the Department of Energy under Contract No. AC05-85ER40216. The research program is divided into three separate tasks, as follows: the study of Transport and Longitudinal Compression of Intense, High-Brightness Beams; the study of Collective Ion Acceleration by Intense Electron Beams and Pulse-Powered Plasma Focus; the study of Microwave Sources and Parameter Scaling for High-Frequency Linacs. This report consists of three sections in which the progress for each task is documented separately. An introduction and synopsis is presented at the beginning of the progress report for each task

  9. Particle accelerator physics

    Wiedemann, Helmut

    2015-01-01

    This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...

  10. Accelerators for Cancer Therapy

    Lennox, Arlene J.

    2000-05-30

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy.

  11. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under contract number AC05-85ER40216-8, is currently in the third year of its three-year funding cycle. This Renewal Proposal requests DOE support for the next three-year period from June 1, 1991 to May 31, 1994. It documents the progress made during the past year and outlines the proposed research program for the next three years. The program consisted of the following three tasks: Task A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' Task B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' Task C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders.'' These tasks will be discussed in this paper

  12. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks

  13. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks

  14. Advanced medical accelerator design

    This report describes the design of an advanced medical facility dedicated to charged particle radiotherapy and other biomedical applications of relativistic heavy ions. Project status is reviewed and some technical aspects discussed. Clinical standards of reliability are regarded as essential features of this facility. Particular emphasis is therefore placed on the control system and on the use of technology which will maximize operational efficiency. The accelerator will produce a variety of heavy ion beams from helium to argon with intensities sufficient to provide delivered dose rates of several hundred rad/minute over large, uniform fields. The technical components consist of a linac injector with multiple PIG ion sources, a synchrotron and a versatile beam delivery system. An overview is given of both design philosophy and selected accelerator subsystems. Finally, a plan of the facility is described

  15. Particle acceleration by pulsars

    The evidence that pulsars accelerate relativistic particles is reviewed, with emphasis on the γ-ray observations. The current state of knowledge of acceleration in strong waves is summarized, with emphasis on the inability of consistent theories to accelerate very high energy particles without converting too much energy into high energy photons. The state of viable models for pair creation by pulsars is summarized, with the conclusion that pulsars very likely lose rotational energy in winds instead of in superluminous strong waves. The relation of the pair creation models to γ-ray observations and to soft X-ray observations of pulsars is outlined, with the conclusion that energetically viable models may exist, but none have yet yielded useful agreement with the extant data. Some paths for overcoming present problems are discussed. The relation of the favored models to cosmic rays is discussed. It is pointed out that the pairs made by the models may have observable consequences for observation of positrons in the local cosmic ray flux and for observations of the 511 keV line from the interstellar medium. Another new point is that asymmetry of plasma supply from at least one of the models may qualitatively explain the gross asymmetry of the X-ray emission from the Crab nebula. It is also argued that acceleration of cosmic ray nuclei by pulsars, while energetically possible, can occur only at the boundary of the bubbles blown by the pulsars, if the cosmic ray composition is to be anything like that of the known source spectrum

  16. LEP copper accelerating cavities

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  17. Accelerator Experiments for Astrophysics

    Ng, Johnny S. T.

    2003-01-01

    Many recent discoveries in astrophysics involve phenomena that are highly complex. Carefully designed experiments, together with sophisticated computer simulations, are required to gain insights into the underlying physics. We show that particle accelerators are unique tools in this area of research, by providing precision calibration data and by creating extreme experimental conditions relevant for astrophysics. In this paper we discuss laboratory experiments that can be carried out at the S...

  18. GPU accelerated face detection

    Mäkelä, J.

    2013-01-01

    Graphics processing units have massive parallel processing capabilities, and there is a growing interest in utilizing them for generic computing. One area of interest is computationally heavy computer vision algorithms, such as face detection and recognition. Face detection is used in a variety of applications, for example the autofocus on cameras, face and emotion recognition, and access control. In this thesis, the face detection algorithm was accelerated with GPU using OpenCL. The goal was...

  19. Compact pulsed accelerator

    The formation of fast pulses from a current charged transmission line and opening switch is described. By employing a plasma focus as an opening switch and diode in the prototype device, a proton beam of peak energy 250 keV is produced. The time integrated energy spectrum of the beam is constructed from a Thomson spectrograph. Applications of this device as an inexpensive and portable charged particle accelerator are discussed. 7 refs., 5 figs., 1 tab

  20. Laser plasma accelerators

    Malka, V.

    2012-01-01

    Research activities on laser plasma accelerators are paved by many significant breakthroughs. This review article provides an opportunity to show the incredible evolution of this field of research which has, in record time, allowed physicists to produce high quality electron beams at the GeV level using compact laser systems. I will show the scientific path that led us to explore different injection schemes and to produce stable, high peak current and high quality electron beams with control ...

  1. Future Accelerator Magnet Needs

    Devred, Arnaud; Yamamoto, A

    2005-01-01

    Superconducting magnet technology is continually evolving in order to meet the demanding needs of new accelerators and to provide necessary upgrades for existing machines. A variety of designs are now under development, including high fields and gradients, rapid cycling and novel coil configurations. This paper presents a summary of R&D programs in the EU, Japan and the USA. A performance comparison between NbTi and Nb3Sn along with fabrication and cost issues are also discussed.

  2. GPU accelerated dislocation dynamics

    Ferroni, Francesco; Tarleton, Edmund; Fitzgerald, Steven

    2014-09-01

    In this paper we analyze the computational bottlenecks in discrete dislocation dynamics modeling (associated with segment-segment interactions as well as the treatment of free surfaces), discuss the parallelization and optimization strategies, and demonstrate the effectiveness of Graphical Processing Unit (GPU) computation in accelerating dislocation dynamics simulations and expanding their scope. Individual algorithmic benchmark tests as well as an example large simulation of a thin film are presented.

  3. Laser-driven electron accelerators

    The following possibilities are discussed: inverse free electron laser (wiggler accelerator); inverse Cerenkov effect; plasma accelerator; dielectric tube; and grating linac. Of these, the grating acceleraton is considered the most attractive alternative

  4. Accelerated Profile HMM Searches.

    Sean R Eddy

    2011-10-01

    Full Text Available Profile hidden Markov models (profile HMMs and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches.

  5. Oxidised cosmic acceleration

    We give detailed proofs of several new no-go theorems for constructing flat four-dimensional accelerating universes from warped dimensional reduction. These new theorems improve upon previous ones by weakening the energy conditions, by including time-dependent compactifications, and by treating accelerated expansion that is not precisely de Sitter. We show that de Sitter expansion violates the higher-dimensional null energy condition (NEC) if the compactification manifold M is one-dimensional, if its intrinsic Ricci scalar R-ring vanishes everywhere, or if R-ring and the warp function satisfy a simple limit condition. If expansion is not de Sitter, we establish threshold equation-of-state parameters w below which accelerated expansion must be transient. Below the threshold w there are bounds on the number of e-foldings of expansion. If M is one-dimensional or R-ring everywhere vanishing, exceeding the bound implies the NEC is violated. If R-ring does not vanish everywhere on M, exceeding the bound implies the strong energy condition (SEC) is violated. Observationally, the w thresholds indicate that experiments with finite resolution in w can cleanly discriminate between different models which satisfy or violate the relevant energy conditions

  6. Accelerated GLAS exposure station

    The Geoscience Laser Altimeter System (GLAS) is being developed by NASA/GSFC to measure the dynamics of the ice sheet mass balance, land, and cloud and atmospheric properties. An instrument altimetric resolution of 10 cm per shot is required. The laser transmitter will be a diode pumped, Q-switched, Nd:YAG laser producing 1064 nm, 100 mJ, 4 ns pulses at 40 Hz repetition rate in a TEM∞ mode. A minimum lifetime goal of 2 billion shots is required per laser transmitter. The performance of the GLAS laser can be limited by physical damage to the optical components caused by the interaction of intense laser energy with the optical coatings and substrates. Very little data exists describing the effects of long duration laser exposure, of 4 ns pulses, on an optical component. An Accelerated GLAS Exposure Station (AGES) is being developed which will autonomously operate and monitor the GLAS laser at an accelerated rate of 500 Hz. The effects of a large number of laser shots will be recorded. Parameters to be monitored include: laser power, pulsewidth, beam size, laser diode drive current and power, Q-switch drive voltage, temperature, and humidity. For comparison, one set of AGES-sister optical components will be used in the non-accelerated GLAS laser and another will be evaluated by a commercial optical damage test facility

  7. Linac transport and acceleration

    The acceleration of intense bunches maintaining high brightness is limited both by single-particle effects, e.g., misalignments, injection errors, and rf-steering, and collective phenomena, where the effects of the longitudinal and transverse wakefield on particles within a single bunch are the most severe. The working group has considered both problems and potentials of linac acceleration from ∼50 MeV to 1 GeV for free electron laser (FEL) applications, as well as from a few Gev to 1 TeV for linear colliders. The outlook for free electron lasers is bright: no fundamental problems seem to arise in the acceleration of peak currents in excess of 100 A with small emittance and low momentum spread. The situation of linear colliders is more complex and more difficult. Two examples, one operating at 11.4 GHz, the other at 30 GHz, are used to illustrate some of the difficulties and the exceedingly tight tolerances required. Both examples are based on round beams, and thus neither benefit from the advantages of flat beams nor address the increased care required in transporting beams of very small emittance in one plane. The working group acknowledges, but did not explore, promising concepts for colliders based on RF superconductivity

  8. TRACKING ACCELERATOR SETTINGS

    Recording setting changes within an accelerator facility provides information that can be used to answer questions about when, why, and how changes were made to some accelerator system. This can be very useful during normal operations, but can also aid with security concerns and in detecting unusual software behavior. The Set History System (SHS) is a new client-server system developed at the Collider-Accelerator Department of Brookhaven National Laboratory to provide these capabilities. The SHS has been operational for over two years and currently stores about IOOK settings per day into a commercial database management system. The SHS system consists of a server written in Java, client tools written in both Java and C++, and a web interface for querying the database of setting changes. The design of the SHS focuses on performance, portability, and a minimal impact on database resources. In this paper, we present an overview of the system design along with benchmark results showing the performance and reliability of the SHS over the last year

  9. Laser driven particle acceleration

    This dissertation summarizes the last ten years of research at the Laboratory of Applied Optics on laser-plasma based electron acceleration. The main result consists of the development and study of a relativistic electron source with unique properties: high energy (100-300 MeV) in short distances (few millimeters), mono-energetic, ultra-short (few fs), stable and tunable. The manuscript describes the steps that led to understanding the physics, and then mastering it in order to produce this new electron source. Non linear propagation of the laser pulse in the plasma is first presented, with phenomena such as non linear wakefield excitation, relativistic and ponderomotive self-focusing in the short pulse regime, self-compression. Acceleration and injection of electrons are then reviewed from a theoretical perspective. Experimental demonstrations of self-injection in the bubble regime and then colliding pulse injection are then presented. These experiments were among the first to produce monoenergetic, high quality, stable and tunable electron beams from a laser-plasma accelerator. The last two chapters are dedicated to the characterization of the electron beam using transition radiation and to its applications to gamma radiography and radiotherapy. Finally, the perspectives of this research are presented in the conclusion. Scaling laws are used to determine the parameters that the electron beams will reach using peta-watt laser systems currently under construction. (author)

  10. CESR Test Accelerator

    Rubin, David L

    2013-01-01

    The Cornell Electron Storage Ring (CESR) was reconfigured in 2008 as a test accelerator to investigate the physics of ultra-low emittance damping rings. During the approximately 40 days/year available for dedicated operation as a test accelerator, specialized instrumentation is used to measure growth and mitigation of the electron cloud, emittance growth due to electron cloud, intra-beam scattering, and ions, and single and multi-bunch instabilities generated by collective effects. The flexibility of the CESR guide field optics and the integration of accelerator modeling codes with the control system have made possible an extraordinary range of experiments. Findings at CesrTA with respect to electron cloud effects, emittance tuning techniques, and beam instrumentation for measuring electron cloud, beam sizes, and beam positions are the basis for much of the design of the ILC damping rings as documented in the ILC-Technical Design Report. The program has allowed the Cornell group to cultivate the kind of talen...

  11. Optimizing accelerator technology

    Katarina Anthony

    2012-01-01

    A new EU-funded research and training network, oPAC, is bringing together 22 universities, research centres and industry partners to optimize particle accelerator technology. CERN is one of the network’s main partners and will host 5 early-stage researchers in the BE department.   A diamond detector that will be used for novel beam diagnostics applications in the oPAC project based at CIVIDEC. (Image courtesy of CIVIDEC.) As one of the largest Marie Curie Initial Training Networks ever funded by the EU – to the tune of €6 million – oPAC extends well beyond the particle physics community. “Accelerator physics has become integral to research in almost every scientific discipline – be it biology and life science, medicine, geology and material science, or fundamental physics,” explains Carsten P. Welsch, oPAC co-ordinator based at the University of Liverpool. “By optimizing the operation of accelerators, all of these...

  12. Acceleration during magnetic reconnection

    Beresnyak, Andrey [Los Alamos National Laboratory; Li, Hui [Los Alamos National Laboratory

    2015-07-16

    The presentation begins with colorful depictions of solar x-ray flares and references to pulsar phenomena. Plasma reconnection is complex, could be x-point dominated or turbulent, field lines could break due to either resistivity or non-ideal effects, such as electron pressure anisotropy. Electron acceleration is sometimes observed, and sometimes not. One way to study this complex problem is to have many examples of the process (reconnection) and compare them; the other way is to simplify and come to something robust. Ideal MHD (E=0) turbulence driven by magnetic energy is assumed, and the first-order acceleration is sought. It is found that dissipation in big (length >100 ion skin depths) current sheets is universal and independent on microscopic resistivity and the mean imposed field; particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. One example of such flow is spontaneous reconnection. This explains hot electrons with a power-law tail in solar flares, as well as ultrashort time variability in some astrophysical sources.

  13. Overview of accelerators in medicine

    Accelerators used for medicine include synchrotrons, cyclotrons, betatrons, microtrons, and electron, proton, and light ion linacs. Some accelerators which were formerly found only at physics laboratories are now being considered for use in hospital-based treatment and diagnostic facilities. This paper presents typical operating parameters for medical accelerators and gives specific examples of clinical applications for each type of accelerator, with emphasis on recent developments in the field

  14. Electron accelerators for environmental protection

    The primary objective of this publication is to provide information suitable for electron accelerators implementation in facilities applying radiation technology for environmental protection. It should be noticed that radiation processing has been successfully used in the fields of crosslinking polymer curing and medical products sterilization for more than 40 years. Practical application of radiation technology today extends on SO2 and NOx removal from the flue gas (one of major power intensive radiation processing), destruction and removal of organic chemicals from water, decreasing bacteria content in the irradiated sludge and waste water. On the other hand the increased awareness of environmental pollution hazards and more stringent waste regulations in many countries may open stronger support for environmentally oriented technologies. This publication provides an evaluation of electron accelerators capabilities in respect of environmental applications where technological and economical criteria are now well defined. In order to determine the potential of electron accelerators, the literature data were examined as well visits and meetings with various accelerator manufacturers were performed by the author. Experience of the author in accelerator facilities construction and exploitation including those which were used for environmental protection are significant part of this publication. The principle of accelerator action was described in Chapter 1. Early development, accelerator classification and fields of accelerators application were included to this chapter as well. Details of accelerator construction was described in Chapter 2 to illustrate physical capability of accelerators to perform the function of ionizing radiation source. Electron beam extraction devices, under beam equipment, electron beam parameters and measuring methods were characterized in this chapter as well. Present studies of accelerator technology was described in Chapter 3, where direct

  15. ACCELERATORS: Nonlinear dynamics in Sardinia

    In the last few years, two schools devoted to accelerator physics have been set up, one on either side of the Atlantic. The US School on High Energy Particle Accelerators has organized Summer Schools on the physics of particle accelerators, hosted by the major American Laboratories, each year since 1981

  16. High intensity circular proton accelerators

    Circular machines suitable for the acceleration of high intensity proton beams include cyclotrons, FFAG accelerators, and strong-focusing synchrotrons. This paper discusses considerations affecting the design of such machines for high intensity, especially space charge effects and the role of beam brightness in multistage accelerators. Current plans for building a new generation of high intensity 'kaon factories' are reviewed. 47 refs

  17. EQUIVALENT QUEUE LENGTH MODEL FOR THE TWO-LANE HIGHWAY UNDER THE TRAFFIC ACCIDENT%双车道公路交通事故下当量排队长度的数学模型

    杨晨姊

    2014-01-01

    The traffic capacity of the highway and queue length of vehicles under the traffic accident are important to analyze the traffic accident.Firstly,the paper discusses the lane-changing during the traffic accident on the two-lane highway and analyzes the status of traffic flow during the Lane -Changing.Then it builds the equivalent queue length model for the two-lane highway under the traffic accident based on the two-fluid theory. Finally,it simulates and analyzes the model.%交通事故下道路的通行能力和车辆排队长度等问题是交通事故分析的重要内容。笔者探讨了双车道公路交通事故持续期间的换道行为,分析了换道期间车流运行的状态,在此基础上,结合二流理论建立了双车道公路交通事故下当量排队长度的数学模型。最后对该模型进行了仿真分析和计算。

  18. "A reader's guide to Calvin's Institutes" by Anthony N. S. Lane; "A theological guide to Calvin's Institutes: essays and analysis" edited by David W. Hall and Peter A. Lillback

    Eglinton, James

    2009-01-01

    Reviews of Anthony N. S. Lane, A Reader's Guide to Calvin's Institutes (Grand Rapids, Mich.: Baker Publishing Group, 2009). David W. Hall and Peter A. Lillback (eds.), A Theological Guide to Calvin's Institutes: Essays and Analysis (Phillipsburg, N.J.: P & R Publishing, 2008)

  19. High intensity proton accelerator program

    Industrial applications of proton accelerators to the incineration of the long-lived nuclides contained in the spent fuels have long been investigated. Department of Reactor Engineering of Japan Atomic Energy Research Institute (JAERI) has formulated the Accelerator Program through the investigations on the required performances of the accelerator and its development strategies and also the research plan using the accelerator. Outline of the Program is described in the present report. The target of the Program is the construction of the Engineering Test Accelerators (ETA) of the type of a linear accelerator with the energy 1.5 GeV and the proton current ∼10 mA. It is decided that the construction of the Basic Technology Accelerator (BTA) is necessary as an intermediate step, aiming at obtaining the required technical basis and human resources. The Basic Technology Accelerator with the energy of 10 MeV and with the current of ∼10 mA is composed of the ion source, RFQ and DTL, of which system forms the mock-up of the injector of ETA. Development of the high-β structure which constitutes the main acceleration part of ETA is also scheduled. This report covers the basic parameters of the Basic Technology Accelerator (BTA), development steps of the element and system technologies of the high current accelerators and rough sketch of ETA which can be prospected at present. (J.P.N.)

  20. APT accelerator. Topical report

    The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation's stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century

  1. VLHC accelerator physics

    Michael Blaskiewicz et al.

    2001-11-01

    A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

  2. APT accelerator. Topical report

    Lawrence, G.; Rusthoi, D. [comp.] [ed.

    1995-03-01

    The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

  3. ACCELERATING NANO-TECHNOLOGICAL

    Jensen, Jens Stissing; Koch, Christian

    2007-01-01

    By viewing the construction industry as a technological innovation system (TIS) this paper discusses possible initiatives to accelerate nanotechnological innovations. The point of departure is a recent report on the application of nano-technology in the Danish construction industry, which concludes...... features of the system are furthermore poorly equipped at identifying potentials within high-tech areas. In order to exploit the potentials of nano-technology it is thus argued that an alternative TIS needs to be established. Initiatives should identify and support “incubation rooms” or marked niches in...

  4. 2014 CERN Accelerator Schools

    2014-01-01

    A specialised school on Power Converters will be held in Baden, Switzerland, from 7 to 14 May 2014. Please note that the deadline for applications is 7 FEBRUARY 2014. A course on Introduction to Accelerator Physics will be held in Prague, Czech Republic, from 31 August to 12 September 2014. Applications are now open for this school; the application deadline is 25 APRIL 2014. Further information on these schools and other CAS events can be found on the CAS website and on the Indico page. For further information please contact Barbara.strasser@cern.ch

  5. Hardware Accelerated Power Estimation

    Coburn, Joel; Raghunathan, Anand

    2011-01-01

    In this paper, we present power emulation, a novel design paradigm that utilizes hardware acceleration for the purpose of fast power estimation. Power emulation is based on the observation that the functions necessary for power estimation (power model evaluation, aggregation, etc.) can be implemented as hardware circuits. Therefore, we can enhance any given design with "power estimation hardware", map it to a prototyping platform, and exercise it with any given test stimuli to obtain power consumption estimates. Our empirical studies with industrial designs reveal that power emulation can achieve significant speedups (10X to 500X) over state-of-the-art commercial register-transfer level (RTL) power estimation tools.

  6. Plasma wake field accelerator

    A new scheme of electron acceleration, employing relativistic electron bunches in a cold plasma, is analyzed. The wake field of a leading bunch is derived in a single-particle model. We then extend the model to include finite bunch length effect. In particular, we discuss the relation between the charge distributions of the driving bunch and the energies transformable to the trailing electrons. It is shown that for symmetric charge distribution of the driving bunches, the maximum energy gain for a driven electron is 2γ0mc2. This limitation can be overcome by introducing asymmetric charge distributions. 13 refs., 5 figs

  7. Accelerated Innovation Pilot

    Davis, Jeffrey

    2012-01-01

    Opportunities: I. Engage NASA team (examples) a) Research and technology calls . provide suggestions to AES, HRP, OCT. b) Use NASA@Work to solicit other ideas; (possibly before R+D calls). II. Stimulate collaboration (examples) a) NHHPC. b) Wharton Mack Center for Technological Innovation (Feb 2013). c) International ] DLR ] :envihab (July 2013). d) Accelerated research models . NSF, Myelin Repair Foundation. III. Engage public Prizes (open platform: InnoCentive, yet2.com, NTL; Rice Business Plan, etc.) IV. Use same methods to engage STEM.

  8. A nonclassical Radau collocation method for solving the Lane-Emden equations of the polytropic index 4.75 ≤ α < 5

    Tirani, M. D.; Maleki, M.; Kajani, M. T.

    2014-11-01

    A numerical method for solving the Lane-Emden equations of the polytropic index α when 4.75 ≤ α ≤ 5 is introduced. The method is based upon nonclassical Gauss-Radau collocation points and Freud type weights. Nonclassical orthogonal polynomials, nonclassical Radau points and weighted interpolation are introduced and are utilized in the interval [0,1]. A smooth, strictly monotonic transformation is used to map the infinite domain x ∈ [0,∞) onto a half-open interval t ∈ [0,1). The resulting problem on the finite interval is then transcribed to a system of nonlinear algebraic equations using collocation. The method is easy to implement and yields very accurate results.

  9. Chicago particle accelerator conference

    Naturally, emphasis at the Particle Accelerator Conference in Chicago in March was on work in the US, just as the newly instituted European Particle Accelerator Conference places emphasis on work in the 'old continent'. All will come together at the international conference in Japan in August. The proposed US Superconducting Supercollider (SSC) was highlighted in the opening talk at Chicago. Progress on this inchoate project to explore the TeV (1000 GeV) energy region by colliding 20 TeV proton beams was reported by the recently-appointed Director of the SSC Laboratory, Roy Schwitters. He reviewed the physics challenges and described progress and plans towards full authorization of construction.This year, the SSC conceptual design will be transformed into a 'site specific' report, now that the location at Waxahachie in Ellis County, Texas, has been selected. The Central Design Group, based in Berkeley for the past few years, will soon move to the Waxahachie region. The top management structure is taking shape and an International Advisory Committee is being formed

  10. Accelerator research studies

    1993-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks.

  11. Accelerator School Success

    2004-01-01

    Accelerator specialists don't grow on trees: training them is the job of the CERN Accelerator School (CAS). Group photo during visit to the Daresbury Laboratory. CAS and the CCLRC Daresbury Laboratory jointly organised a specialised school on Power Converters in Warrington, England from 12-18 May 2004. The last CAS Power Converter course was in 1990, so there was plenty of ground to cover. The challenging programme proposed a review of the state of the art and the latest developments in the field, including 30 hours of tuition. The school also included a visit to the CCLRC Daresbury laboratory, a one-day excursion to Liverpool and Chester and a themed (Welsh medieval) dinner at the school's closure. A record attendance of 91 students of more than 20 different nationalities included not only participants from Europe and North America but also from Armenia, Taiwan, India, Turkey, Iran and for the first time, fee-paying students from China and Australia. European industry showed a welcome and solid interest in...

  12. Medical Proton Accelerator Project

    A project for a medical proton accelerator for cancer treatment is outlined. The project is motivated by the need for a precise modality for cancer curing especially in children. Proton therapy is known by its superior radiation and biological effectiveness as compared to photon or electron therapy. With 26 proton and 3 heavy-ion therapy complexes operating worldwide only one (p) exists in South Africa, and none in south Asia and the Middle East. The accelerator of choice should provide protons with energy 75 MeV for eye treatment and 250 MeV for body treatment. Four treatment rooms are suggested: two with isocentric gantries, one with fixed beams and one for development. Passive scanning is recommended. The project can serve Middle East and North Africa with ∼ 400 million populations. The annual capacity of the project is estimated as 1,100 to be compared with expected radiation cases eligible for proton cancer treatment of not less than 200,000

  13. Broadband accelerator control network

    A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz bandwidth Digital Control channel using CSMA-CA protocol is provided for digital data transmission, with 8 access nodes available over the length of the RELWAY. Each node consists of an rf modem and a microprocessor-based store-and-forward message handler which interfaces the RELWAY to a branch line implemented in GPIB. A gateway to the RELWAY control channel for the (preexisting) AGS Computerized Accelerator Operating system has been constructed using an LSI-11/23 microprocessor as a device in a GPIB branch line. A multilayer communications protocol has been defined for the Digital Control Channel, based on the ISO Open Systems Interconnect layered model, and a RELWAY Device Language defined as the required universal language for device control on this channel

  14. Washington Accelerator Conference

    Highlights of the 1993 Particle Accelerator Conference, held in Washington in May, were picked out in the previous issue (page 18). Talks on the big hadron colliders reflected the sea-change in the accelerator world where the scale, complexity and cost of the front-line projects has slowed the pace of developments (not unlike the scene in particle physics itself). Speaking before the anti-SSC vote in the House of Representatives in June, Dick Briggs reviewed the situation at the SSC Superconducting Supercollider in Ellis County, Texas. The linac building is near completion and the Low Energy Booster will be ready to receive components early next year. Tunnelling for the Main Ring is advancing rapidly with four boring machines in action. Five miles of tunnel have been completed since January and the pace has now stepped up to nearly a mile each week. The superconducting magnet news is good. Following the successful initial string test of a half cell of the magnet lattice, a two-ring full cell with all associated services is being assembled. The mechanical robustness of the magnet design was confirmed when a dipole was taken to 9.7 T when cooled to 1.8 K. In the Magnet Test Lab itself, ten test stands are installed and equipped

  15. Accelerator Technology: Geodesy and Alignment for Particle Accelerators

    Missiaen, D

    2013-01-01

    This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '8.9 Geodesy and Alignment for Particle Accelerators' of the Chapter '8 Accelerator Technology' with the content: 8.9 Geodesy and Alignment for Particle Accelerators 8.9.1 Introduction 8.9.2 Reference and Co-ordinate Systems 8.9.3 Definition of the Beam Line on the Accelerator Site 8.9.4 Geodetic Network 8.9.5 Tunnel Preliminary Works 8.9.6 The Alignment References 8.9.7 Alignment of Accelerator Components 8.9.8 Permanent Monitoring and Remote Alignment of Low Beta Quadrupoles 8.9.9 Alignment of Detector Components

  16. 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection

    JAS - Joint US-CERN-Japan-Russia Accelerator School

    2016-01-01

    Many particle accelerators operate with very high beam power and very high energy stored in particle beams as well as in magnet systems. In the future, the beam power in high intensity accelerators will further increase. The protection of the accelerator equipment from the consequences of uncontrolled release of the energy is essential. This was the motivation for organizing a first school on beam losses and accelerator protection (in general referred to as machine protection). During the school the methods and technologies to identify, mitigate, monitor and manage the technical risks associated with the operation of accelerators with high-power beams or subsystems with large stored energy were presented. At the completion of the school the participants should have been able to understand the physical phenomena that can damage machine subsystems or interrupt operations and to analyze an accelerator facility to produce a register of technical risks and the corresponding risk mitigation and management strategie...

  17. CAS CERN Accelerator School: Advanced accelerator physics. Proceedings. Vol. 1

    This advanced course on general accelerator physics is the second of the biennial series given by the CERN Accelerator School and follows on from the first basic course given at Gif-sur-Yvette, Paris, in 1984. Stress is placed on the mathematical tools of Hamiltonian mechanics and the Vlasov and Fokker-Planck equations, which are widely used in accelerator theory. The main topics treated in this present work include: nonlinear resonances, chromaticity, motion in longitudinal phase space, growth and control of longitudinal and transverse beam emittance, space-charge effects and polarization. The seminar programme treats some specific accelerator techniques, devices, projects and future possibilities. (orig.)

  18. CAS CERN Accelerator School: Advanced accelerator physics. Proceedings. Vol. 2

    This advanced course on general accelerator physics is the second of the biennial series given by the CERN Accelerator School and follows on from the first basic course given at Gif-sur-Yvette, Paris, in 1984. Stress is placed on the mathematical tools of Hamiltonian mechanics and the Vlasov and Fokker-Planck equations, which are widely used in accelerator theory. The main topics treated in this present work include: nonlinear resonances, chromaticity, motion in longitudinal phase space, growth and control of longitudinal and transverse beam emittance, space-charge effects and polarization. The seminar programme treats some specific accelerator techniques, devices, projects and future possibilities. (orig.)

  19. CERN Accelerator School: Registration open for Advanced Accelerator Physics course

    2015-01-01

    Registration is now open for the CERN Accelerator School’s Advanced Accelerator Physics course to be held in Warsaw, Poland from 27 September to 9 October 2015.   The course will be of interest to physicists and engineers who wish to extend their knowledge of accelerator physics. The programme offers core lectures on accelerator physics in the mornings and a practical course with hands-on tuition in the afternoons.  Further information can be found at: http://cas.web.cern.ch/cas/Poland2015/Warsaw-advert.html http://indico.cern.ch/event/361988/

  20. CERN Accelerator School: Registration open for Advanced Accelerator Physics course

    2015-01-01

    Registration is now open for the CERN Accelerator School’s Advanced Accelerator Physics course to be held in Warsaw, Poland from 27 September to 9 October 2015.   The course will be of interest to physicists and engineers who wish to extend their knowledge of Accelerator Physics. The programme offers core lectures on accelerator physics in the mornings and a practical course with hands-on tuition in the afternoons.  Further information can be found at: http://cas.web.cern.ch/cas/Poland2015/Warsaw-advert.html http://indico.cern.ch/event/361988/