Track Switch Research Articles

클러터 환경에서 Track Coalescence & Switch 감소를 위한 JPDA 기법연구

Data association is important technology which designate final destination in the target tracking. The joint probabilistic data association(JPDA) algorithm provides excellent ability to maintain track on multiple targets. Currently, it is not easily implemented in real time because of track coalescence & switch. The aim of this paper is to develop probabilistic filters that increase JPDA`s sensitivity and decrease track coalescence & switch in a cluttered environments.

Impedance-activated microseparator based on amplitude modulation sensing and dielectrophoretic switching methods

We present an impedance-activated microseparator that can detect and isolate microparticles according to size. Using the amplitude modulation sensing method, the impedance-activated microseparator precisely detected the size of 5-, 8-, and 10-μm polystyrene beads. To obtain high sensitivity, sensing electrodes were designed in a parallel overlap electrode structure, including two excitation electrodes patterned on the roof and a sensing electrode patterned on the bottom floor. The peak output voltage was proportionally correlated with particle volume; thus, the measured peak output values were used both to calculate microparticle size and to count the number of microparticles. Experimental results showed that volume resolution of the impedance-activated microseparator is less than 30 μm3 and the minimum detectable particle size is approximately 2 μm in diameter. By using the dielectrophoresis-based track switching method, the proposed impedance-activated microseparator could isolate microparticles according to their size with greater than 90% separation efficiency. Consequently, the proposed impedance-activated microseparator may facilitate the identification and separation of microparticles according to size from a heterogeneous admixture.

An Evaluation of Redundancy Concepts for Fault Tolerant Railway Track Switching

Railway track switching provides necessary flexibility to a rail network, but also introduces many single points of failure. Other industries have resorted to redundancy to provide the fault tolerance necessary to achieve specified safety and operational goals in similar critical systems, yet this approach has not yet been applied to track switching. This paper explores several system concepts for redundancy in track switching, and attempts a rudimentary cost/benefit analysis of each. Mechanical design is not considered, the paper being a feasibility study only. Finally, concept performance is evaluated in a case study at Derby Midland station (UK). The results show that providing redundancy which utilises only existing technology demonstrates some gains in operational availability. However, it is unlikely to be cost effective, and for redundancy in track switching to be a realistic prospect, novel designs and technologies may be necessary.

Rotational dynamics of cargos at pauses during axonal transport

Direct visualization of axonal transport in live neurons is essential for our understanding of the neuronal functions and the working mechanisms of microtubule-based motor proteins. Here we use the high-speed single particle orientation and rotational tracking technique to directly visualize the rotational dynamics of cargos in both active directional transport and pausing stages of axonal transport, with a temporal resolution of 2 ms. Both long and short pauses are imaged, and the correlations between the pause duration, the rotational behaviour of the cargo at the pause, and the moving direction after the pause are established. Furthermore, the rotational dynamics leading to switching tracks are visualized in detail. These first-time observations of cargo's rotational dynamics provide new insights on how kinesin and dynein motors take the cargo through the alternating stages of active directional transport and pause.

Developing a Real-Time Track Display That Operators Do Not Hate

We formulate a method of estimating target states that minimizes the mean optimal subpattern assignment (MOSPA) metric, applied suboptimally to a multi-hypothesis tracker (MHT) and optimally to a particle filter. This gives the operator a display of the targets with reduced jitter and track switching.

A new input system for disabled users involving eye gaze tracker and scanning interface

PurposeThis paper aims to present a new input interaction system for people with severe disabilities. The new system works based on eye gaze tracking and single switch scanning interaction techniques. It combines eye gaze tracking and scanning in a unique way which is faster than only scanning‐based systems while more comfortable to use than only eye gaze tracking‐based systems, which is also supported by a user study.Design/methodology/approachThe aim was to design a new interaction technique combining eye tracking and scanning technique for severely disabled people. A comparative study with eight users involving only an eye tracking system and the system combining eye tracking and scanning was conducted.FindingsThe participants rated the new system easier and less strenuous to use than the eye gaze tracking‐based system, while the new system did not slow the speed of interaction.Originality/valueThis new method based on eye gaze tracking and single switch scanning interaction techniques has potential to be a new interaction technique combining free source eye tracker and scanning switches. It is hoped users who can move a limb to use a single switch‐based scanning system will be hugely benefitted by this new system.

All change: switching tracks to Learning Zone 2.0

Nearly four years ago, the University of the Arts London launched its first flexible learning space for students, called the Learning Zone. The service model for the space was underpinned by an ethos of peer support. When London’s Crossrail Development project necessitated relocation, the Learning Zone team had to build the service all over again. Learning Zone 2.0 was a chance to reflect on the use and design of the space . . . and to improve on the first version. Despite personnel changes, building delays and lost furniture and equipment, the new space opened in May 2010.

Body effect compensation of analog switches using variable voltage function

This paper introduces a new technique for reducing the body effect on the channel on-resistance of analog switches. In this technique, the gate of bootstrapped sampling switch tracks the input signal with a variable voltage function. Rail-to-rail performance of proposed switch makes it suitable for low voltage applications. The simulation results show that the proposed technique can significantly improve the dynamic performance of a sample-and-hold circuit.

Relieving the burden of track switch in modern hard disk drives

In this work, we propose a novel hard disk technique, "AV Disk", for modern multimedia applications. Modern hard disk drives adopt complex sector layout mechanisms to reduce track and head switch overhead. While these complex sector layout mechanism can reduce average overhead involved in the track and head switch, they bring larger variability in the overhead. From a multimedia application's point of view, it is important to minimize the worst case I/O latency rather than to improve the average IO latency. We focus our effort to minimize track switch overhead as well as the variability in track switch overhead involved in disk I/O. We propose that track of the hard disk drive is aligned with a certain IO size. In this work, we develop an elaborate performance model with which we can compute the optimal IO unit size for multimedia applications. We propose that hard disk controller is responsible for positioning data blocks in the hard disk platter in such a manner that I/O units are not placed across the track boundaries, where a single I/O unit has size of 32---128 KByte. Optimal IO unit size is used in aligning the tracks in hard disk drives. We develop Skewed Sector Sparing technique in aligning a track with a given IO size. However, when the I/O unit for alignment is increased to 128 KByte, 17% of the disk space becomes unusable. Despite the decreased storage area, track aligning technique increases the overall performance of the hard disk. According to our simulation-based experiment, overall disk performance increases about 5---25%. Given that capacity of hard disk increases 100% every year, we cautiously regard it as reasonable tradeoff to increase the I/O latency of the disk.

Incremental Train Control System

In 1995, GE started development of the incremental train control system (ITCS) for Amtrak to use on its Michigan corridor between Detroit and Chicago. The primary objective for ITCS was to allow Amtrak passenger trains to operate at 110 mi/h intermixed with freight traffic. To achieve this objective, the traditional wayside signal system would be enhanced with a positive train control (PTC) system to enforce the wayside signal indications (train movement authorities) and operating speed limits. Additionally, the highway-rail grade crossings had to provide the required warning time for trains operating at higher speeds than for what the crossings had originally been designed (79 mi/h). ITCS in Michigan is a fail-safe (vital) positive train control system that overlays the existing signal system for improved safety and provides a cost-effective solution for high-speed train operation. ITCS meets the requirements for PTC, a train control system recently mandated by the U.S. federal government to prevent trainto-train collisions, over-speed derailments, incursions into roadway worker zones, and movement over a misaligned track switch.

Extract and infer quickly

The modern hard disk drive is a complex and complicated device. It consists of 2--4 heads, thousands of sectors per track, several hundred thousands of tracks, and tens of zones. The beginnings of adjacent tracks are placed with a certain angular offset. Sectors are placed on the tracks and accessed in some order. Angular offset and sector placement order vary widely subject to vendors and models. The success of an efficient file and storage subsystem design relies on the proper understanding of the underlying storage device characteristics. The characterization of hard disk drives has been a subject of intense research for more than a decade. The scale and complexity of state-of-the-art hard disk drive technology calls for a new way of extracting and analyzing the characteristics of the hard disk drive. In this work, we develop a novel disk characterization suite, DIG (Disk Geometry Analyzer), which allows us to rapidly extract and characterize the key performance metrics of the modern hard disk drive. Development of this tool is accompanied by thorough examination of four off-the-shelf hard disk drives. DIG consists of three key ingredients: O (1) a track boundary detection algorithm; O (log n ) a zone boundary detection algorithm; and hybrid sampling based seek time profiling. We particularly focus on addressing the scalability aspect of disk characterization. With DIG, we are able to extract key metrics of hard disk drives, for example, track sizes, zone information, sector geometry and so on, within 3--20 minutes. DIG allows us to determine the sector layout mechanism of the underlying hard disk drive, for example, hybrid serpentine, cylinder serpentine, and surface serpentine, and to a build complete sector map from LBN to the three dimensional space of (Cylinder, Head, Sector). Examining the hard disk drives with DIG, we made a number of important observations. In modern hard disk drives, head switch overhead is far greater than track switch overhead. It seems that hard disk drive vendors put greater emphasis on reducing the number of head switches for data access. Most disk vendors use surface serpentine, cylinder serpentine, or hybrid serpentine schemes in laying sectors on the platters. The legacy seek time model, which takes the form of a + b √ d leaves much to be desired for use in modern hard disk drives especially for short seeks (less than 5000 tracks). We compare the performance of the DIG against the existing state-of-the-art disk profiling algorithm. Compared to the existing state-of-the-art disk characterization algorithm, the DIG algorithm significantly decreases the time to extract comprehensive sector geometry information from 1920 minutes to 7 minutes and 1927 minutes to 180 minutes in best and worst case scenarios, respectively.

Improving the cyber security of SCADA communication networks

 SCADA: Supervisory control and data acquisition  SCADA networks enable operating many devices remotely such as track switches, traffic signals, electric circuit breakers, valves, relays, sensors, and water and gas pumps.

Surface-Discharge Switches for High-Performance Closing Applications

Results of experiments conducted to characterize the performance of a surface tracking switch employing surface discharge phenomena as a high-performance, self-closing, isolation switch for high-energy applications are described. These experiments, conducted under both dc and pulsed conditions, lead to a model of switch operation that enables the design of such switches for multi-megampere operation. This paper describes the successful implementation of a surface tracking switch as an operational component in several high-current pulsed power systems, and offers some insight into the operation of surface-tracking switches that may assist in future work to apply the technique as a triggered switch in very-high-energy and high-voltage systems.

Maneuverability—General Issues

Maneuvers may be defined as a series of changes in direction and position for a specified purpose (as in changing course, switching tracks, or docking). Although the definition excludes hovering, this is considered to be a maneuver by biologists. Maneuvers are typically complex, combining more than one translational and rotational component. They are usually driven by hydrodynamic forces, which may be classified as trimming (steering), driven by the kinetic energy of a moving animal, or powered forces, driven by force generation by the control surfaces themselves. Force production by effectors are affected by molecular structure, material properties, degrees of freedom for movement, the number of propulsors working together, and interactions with other organisms/objects, as well as time through a maneuver and/or a powered fin beat. The result is a large repertoire of maneuvering behaviors and high redundancy in control systems. There is no unanimity on quantifying maneuvering performance, but maximum capabilities appear to be most appropriate. Performance metrics will vary from maneuver to maneuver and the scaling product group seems unlikely even for specified maneuvers. An exception is relative volume swept out. Seeking inspiration from biology for the design of autonomous underwater vehicles requires explicit a priori statements of mission goals.

TIME-VARYING FAILURE RATE FOR SYSTEM RELIABILITY ANALYSIS IN LARGE-SCALE RAILWAY RISK ASSESSMENT SIMULATION

For large-scale dynamic railway traffic control systems, the reliability analysis and risk assessment are important for system evaluation, decision making and enforcement of performance-based safety-critical standards. The Axiomatic Safety-Critical Assessment Process (ASCAP) developed at the University of Virginia's Center of Rail Safety-Critical Excellence provides a dynamic Monte Carlo simulation methodology for the quantitative risk assessment of large-scale rail systems. An appropriate reliability model is critical for effective and valid ASCAP simulation results. In reliability engineering, it is know that the electrical and mechanical equipment, such as switch machines, track circuits and trip-stops in railway infrastructure, usually manifest deterioration and/or improvement in reliability over time. A constant failure rate, which entails an exponential distribution of the object's life-time, may not be sufficient and appropriate. A time-varying fatigue rate is adopted in the reliability probabilistic model, which is presented in this paper. The Weibull distribution is one of the most widely used distributions for modeling lifetimes and the Weibull process is particularly suitable for modeling reparable systems because of their flexibility in shaping and scaling time-varying failure rates over time. The algorithm of the Weibull model and the Monte Carlo simulation are presented and the numerical results from applying the method are also provided.

Quantum control design via adaptive tracking

An adaptive tracking algorithm is developed to achieve quantum system control field designs. The adaptive algorithm has the advantage of operating noniteratively to efficiently find desirable controls, and has the feature of high stability by suppressing the influence of disturbances from tracking singularities. The core of the adaptive tracking control algorithm is a self-learning track switch technique which is triggered by monitoring of the evolving system trajectory. The adaptive tracking algorithm is successfully tested for population transfer.

Condition monitoring of railway electric point machines

An electric point machine is a motor-driven device which operates railway track switches (points). Failure of such a device causes delay to trains and, on privatised railways, is likely to incur a financial penalty for the infrastructure owner. The most probable types of fault occurring with a typical point machine design are described. Using analyses of the results of laboratory and field tests, techniques for condition monitoring are reviewed. A net energy technique is proposed and is shown to produce discrimination and repeatability. The technique uses non-invasive sensors and may have a pay-back period of under one year for a large installation.

Doing Engineering: The Career Attainment and Mobility of Caucasian, Black and Asian-American Engineers

Chapter 1 The Rise of the Engineering Profession Chapter 2 Trends in Participation and Profile of Engineers Chapter 3 Theoretical Approaches to Stratification in Engineering Chapter 4 Getting In: Engineers for Hire Chapter 5 Fitting In: Professional Identity and Commitment Chapter 6 Beyond Engineering: Crossing Over the Drawing Board Chapter 7 Track Switching and Back Tracking: The (Un)making of a Manager Chapter 8 Conclusion: The Future of Engineers in Engineering and Management

Trackage modelling and algorithms for finding the shortest train route

This paper deals with two models of track network in a railway station and algorithms for finding the shortest train route. In the first model - a weighted digraph - two vertices represent a track or a switch track. Edges of a digraph are understood as the possible transitions between tracks. In the second model - a non-oriented edge weighted graph - the edges represent tracks and the vertices match the connections between tracks. Algorithms for finding a shortest route were designed and verified for both models. These algorithms respect rules for the movement of rail vehicles, as well as their length and the occupation of tracks by other rolling stock.

Contact Geometry Between a Wheelset and Track. Calculation Algorithms and Contact Geometry on Switch Track.

Contact geometry between a wheelset and track is a fundamental problem of railway vehicle dynamics. This paper scrutinizes two dimensional contact geometry. Firstly, the independent variable of the contact geometry is investigated. It is shown that the roll displacement of a wheelset is superior to the lateral displacement as an independent variable especially in flange-contact area. Secondly, minimum-value search for the contact problem is investigated. It is shown that the gradient method is superior to the displacement method from the view point of calculation time. As an application of the algorithms, contact geometry on switch track, which is important in view of safety, is calculated for worn profiles as well as designed profiles.