3,181 research outputs found
On the Experimental Evaluation of Vehicular Networks: Issues, Requirements and Methodology Applied to a Real Use Case
One of the most challenging fields in vehicular communications has been the
experimental assessment of protocols and novel technologies. Researchers
usually tend to simulate vehicular scenarios and/or partially validate new
contributions in the area by using constrained testbeds and carrying out minor
tests. In this line, the present work reviews the issues that pioneers in the
area of vehicular communications and, in general, in telematics, have to deal
with if they want to perform a good evaluation campaign by real testing. The
key needs for a good experimental evaluation is the use of proper software
tools for gathering testing data, post-processing and generating relevant
figures of merit and, finally, properly showing the most important results. For
this reason, a key contribution of this paper is the presentation of an
evaluation environment called AnaVANET, which covers the previous needs. By
using this tool and presenting a reference case of study, a generic testing
methodology is described and applied. This way, the usage of the IPv6 protocol
over a vehicle-to-vehicle routing protocol, and supporting IETF-based network
mobility, is tested at the same time the main features of the AnaVANET system
are presented. This work contributes in laying the foundations for a proper
experimental evaluation of vehicular networks and will be useful for many
researchers in the area.Comment: in EAI Endorsed Transactions on Industrial Networks and Intelligent
Systems, 201
New Cdc Design Tool For Analog Layout Workflow
The placement and routing on CMOS analog layout design had always been a time consuming and irritating process due to large amount of transistor devices placements, arrangements and a lot of critical nets routing constraint. Manual efforts to complete analog layout design took few weeks to monthsâ time in previous project cycle according to the complexity of the circuit. In the meantime, designer needs to convert the devices from schematic into layout in canvas of layout editor, and then arrange the devices accordingly one by one or group by group by moving the devices in order to complete device placement. While for routing, even though there are different auto-routers in existing layout editing tool, but these routers are mostly developed for digital design and unable to route analog signals precisely especially when there are constraints for the routing like matching and shielding. This research presents a new automation solution, Cartoon Diagram Compiler (CDC) tool that enabling a significant productivity improvement on analog layout design. The automation tool provides capability to drag-and-drop the transistor devices/instance cells from schematics canvas to floor planning canvas and is able to auto-place non-critical cells and devices in a virtual mode before converting into real layout. After the floorplan/placement fulfill the design requirement, topologies generator can be used for quick preview of routing option and auto-router support for constrained (shield critical net) and un-constrained nets routing. The area and routing quality nearly matched with hand-drawn layout. The CDC tool has been compare and evaluated on Intel in-house analog layout design projects. In research evaluation, the average time to complete manual device placement and layout routing required 640 minutes and 554 minutes respectively. With device placement and layout routing process only required 139 minutes and 112 minutes or significant reduction in period of about 5.14x and 6.31x respectively. In conclusion, CDC tool increases the productivity by allowing fully automatic derivation of placement and routing, incremental design updates and smart placement guaranteeing design rule free from violation
IEEE Access Special Section Editorial: Big Data Technology and Applications in Intelligent Transportation
During the last few years, information technology and transportation industries, along with automotive manufacturers and academia, are focusing on leveraging intelligent transportation systems (ITS) to improve services related to driver experience, connected cars, Internet data plans for vehicles, traffic infrastructure, urban transportation systems, traffic collaborative management, road traffic accidents analysis, road traffic flow prediction, public transportation service plan, personal travel route plans, and the development of an effective ecosystem for vehicles, drivers, traffic controllers, city planners, and transportation applications. Moreover, the emerging technologies of the Internet of Things (IoT) and cloud computing have provided unprecedented opportunities for the development and realization of innovative intelligent transportation systems where sensors and mobile devices can gather information and cloud computing, allowing knowledge discovery, information sharing, and supported decision making. However, the development of such data-driven ITS requires the integration, processing, and analysis of plentiful information obtained from millions of vehicles, traffic infrastructures, smartphones, and other collaborative systems like weather stations and road safety and early warning systems. The huge amount of data generated by ITS devices is only of value if utilized in data analytics for decision-making such as accident prevention and detection, controlling road risks, reducing traffic carbon emissions, and other applications which bring big data analytics into the picture
Bus rapid transit
Effective public transit is central to development. For the vast majority of developing city residents, public transit is the only practical means to access employment, education, and public services, especially when such services are beyond the viable distance of walking or cycling. Unfortunately, the current state of public transit services in developing cities often does little to serve the actual mobility needs of the population. Bus services are too often unreliable, inconvenient and dangerous.
In response, transport planners and public officials have sometimes turned to extremely costly mass transit alternatives such as rail-based metros. Due to the high costs of rail infrastructure, cities can only construct such systems over a few kilometres in a few limited corridors. The result is a system that does not meet the broader transport needs of the population. Nevertheless, the municipality ends up with a long-term debt that can affect investment in more pressing areas such as health, education, water, and sanitation.
However, there is an alternative between poor public transit service and high municipal debt. Bus Rapid Transit (BRT) can provide high-quality, metro-like transit service at a fraction of the cost of other options. This document provides municipal officials, non-governmental organizations, consultants, and others with an introduction to the concept of BRT as well as a step-by-step process for successfully planning a BRT system
What impressions do users have after a ride in an automated shuttle? An interview study
In the future, automated shuttles may provide on-demand transport and serve as feeders to public transport systems. However, automated shuttles will only become widely used if they are accepted by the public. This paper presents results of an interview study with 30 users of an automated shuttle on the EUREF (EuropĂ€isches Energieforum) campus in Berlin-Schöneberg to obtain in-depth understanding of the acceptance of automated shuttles as feeders to public transport systems. From the interviews, we identified 340 quotes, which were classified into six categories: (1) expectations about the capabilities of the automated shuttle (10% of quotes), (2) evaluation of the shuttle performance (10%), (3) service quality (34%), (4) risk and benefit perception (15%), (5) travel purpose (25%), and (6) trust (6%). The quotes indicated that respondents had idealized expectations about the technological capabilities of the automated shuttle, which may have been fostered by the media. Respondents were positive about the idea of using automated shuttles as feeders to public transport systems but did not believe that the shuttle will allow them to engage in cognitively demanding activities such as working. Furthermore, 20% of respondents indicated to prefer supervision of shuttles via an external control room or steward on board over unsupervised automation. In conclusion, even though the current automated shuttle did not live up to the respondentsâ expectations, respondents still perceived automated shuttles as a viable option for feeders to public transport systems.Green Open Access added to TU Delft Institutional Repository âYou share, we take care!â â Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and PlanningHuman-Robot InteractionIntelligent VehiclesTransport and Plannin
A Massively Parallel Dynamic Programming for Approximate Rectangle Escape Problem
Sublinear time complexity is required by the massively parallel computation
(MPC) model. Breaking dynamic programs into a set of sparse dynamic programs
that can be divided, solved, and merged in sublinear time.
The rectangle escape problem (REP) is defined as follows: For
axis-aligned rectangles inside an axis-aligned bounding box , extend each
rectangle in only one of the four directions: up, down, left, or right until it
reaches and the density is minimized, where is the maximum number
of extensions of rectangles to the boundary that pass through a point inside
bounding box . REP is NP-hard for . If the rectangles are points of a
grid (or unit squares of a grid), the problem is called the square escape
problem (SEP) and it is still NP-hard.
We give a -approximation algorithm for SEP with with time
complexity . This improves the time complexity of existing
algorithms which are at least quadratic. Also, the approximation ratio of our
algorithm for is which is tight. We also give a
-approximation algorithm for REP with time complexity and
give a MPC version of this algorithm for which is the first parallel
algorithm for this problem
An Orientation & Mobility Aid for People with Visual Impairments
Orientierung&MobilitaÌt (O&M) umfasst eine Reihe von Techniken fuÌr Menschen mit SehschaÌdigungen, die ihnen helfen, sich im Alltag zurechtzufinden. Dennoch benoÌtigen sie einen umfangreichen und sehr aufwendigen Einzelunterricht mit O&M Lehrern, um diese Techniken in ihre taÌglichen AblaÌufe zu integrieren. WaÌhrend einige dieser Techniken assistive Technologien benutzen, wie zum Beispiel den Blinden-Langstock, Points of Interest Datenbanken oder ein Kompass gestuÌtztes Orientierungssystem, existiert eine unscheinbare KommunikationsluÌcke zwischen verfuÌgbaren Hilfsmitteln und Navigationssystemen.
In den letzten Jahren sind mobile Rechensysteme, insbesondere Smartphones, allgegenwaÌrtig geworden. Dies eroÌffnet modernen Techniken des maschinellen Sehens die MoÌglichkeit, den menschlichen Sehsinn bei Problemen im Alltag zu unterstuÌtzen, die durch ein nicht barrierefreies Design entstanden sind. Dennoch muss mit besonderer Sorgfalt vorgegangen werden, um dabei nicht mit den speziellen persoÌnlichen Kompetenzen und antrainierten Verhaltensweisen zu kollidieren, oder schlimmstenfalls O&M Techniken sogar zu widersprechen.
In dieser Dissertation identifizieren wir eine raÌumliche und systembedingte LuÌcke zwischen Orientierungshilfen und Navigationssystemen fuÌr Menschen mit SehschaÌdigung. Die raÌumliche LuÌcke existiert hauptsaÌchlich, da assistive Orientierungshilfen, wie zum Beispiel der Blinden-Langstock, nur dabei helfen koÌnnen, die Umgebung in einem limitierten Bereich wahrzunehmen, waÌhrend Navigationsinformationen nur sehr weitlaÌufig gehalten sind. ZusaÌtzlich entsteht diese LuÌcke auch systembedingt zwischen diesen beiden Komponenten â der Blinden-Langstock kennt die Route nicht, waÌhrend ein Navigationssystem nahegelegene Hindernisse oder O&M Techniken nicht weiter betrachtet. Daher schlagen wir verschiedene AnsaÌtze zum SchlieĂen dieser LuÌcke vor, um die Verbindung und Kommunikation zwischen Orientierungshilfen und Navigationsinformationen zu verbessern und betrachten das Problem dabei aus beiden Richtungen. Um nuÌtzliche relevante Informationen bereitzustellen, identifizieren wir zuerst die bedeutendsten Anforderungen an assistive Systeme und erstellen einige SchluÌsselkonzepte, die wir bei unseren Algorithmen und Prototypen beachten.
Existierende assistive Systeme zur Orientierung basieren hauptsaÌchlich auf globalen Navigationssatellitensystemen. Wir versuchen, diese zu verbessern, indem wir einen auf Leitlinien basierenden Routing Algorithmus erstellen, der auf individuelle BeduÌrfnisse anpassbar ist und diese beruÌcksichtigt. Generierte Routen sind zwar unmerklich laÌnger, aber auch viel sicherer, gemaÌĂ den in Zusammenarbeit mit O&M Lehrern erstellten objektiven Kriterien. AuĂerdem verbessern wir die VerfuÌgbarkeit von relevanten georeferenzierten Datenbanken, die fuÌr ein derartiges bedarfsgerechtes Routing benoÌtigt werden. Zu diesem Zweck erstellen wir einen maschinellen Lernansatz, mit dem wir Zebrastreifen in Luftbildern erkennen, was auch uÌber LaÌndergrenzen hinweg funktioniert, und verbessern dabei den Stand der Technik.
Um den Nutzen von MobilitaÌtsassistenz durch maschinelles Sehen zu optimieren, erstellen wir O&M Techniken nachempfundene AnsaÌtze, um die raÌumliche Wahrnehmung der unmittelbaren Umgebung zu erhoÌhen. Zuerst betrachten wir dazu die verfuÌgbare FreiflaÌche und informieren auch uÌber moÌgliche Hindernisse. Weiterhin erstellen wir einen neuartigen Ansatz, um die verfuÌgbaren Leitlinien zu erkennen und genau zu lokalisieren, und erzeugen virtuelle Leitlinien, welche Unterbrechungen uÌberbruÌcken und bereits fruÌhzeitig Informationen uÌber die naÌchste Leitlinie bereitstellen. AbschlieĂend verbessern wir die ZugaÌnglichkeit von FuĂgaÌngeruÌbergaÌngen, insbesondere Zebrastreifen und FuĂgaÌngerampeln, mit einem Deep Learning Ansatz.
Um zu analysieren, ob unsere erstellten AnsaÌtze und Algorithmen einen tatsaÌchlichen Mehrwert fuÌr Menschen mit SehschaÌdigung erzeugen, vollziehen wir ein kleines Wizard-of-Oz-Experiment zu unserem bedarfsgerechten Routing â mit einem sehr ermutigendem Ergebnis. Weiterhin fuÌhren wir eine umfangreichere Studie mit verschiedenen Komponenten und dem Fokus auf FuĂgaÌngeruÌbergaÌnge durch. Obwohl unsere statistischen Auswertungen nur eine geringfuÌgige Verbesserung aufzeigen, beeinfluĂt durch technische Probleme mit dem ersten Prototypen und einer zu geringen EingewoÌhnungszeit der Probanden an das System, bekommen wir viel versprechende Kommentare von fast allen Studienteilnehmern. Dies zeigt, daĂ wir bereits einen wichtigen ersten Schritt zum SchlieĂen der identifizierten LuÌcke geleistet haben und Orientierung&MobilitaÌt fuÌr Menschen mit SehschaÌdigung damit verbessern konnten
The Design of a System Architecture for Mobile Multimedia Computers
This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies
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Layer assignment and routing optimization for advanced technologies
As VLSI technology scales to deep sub-micron and beyond, it becomes
increasingly challenging to achieve timing closure for VLSI design. Since a
complete design flow consists of several phases, such as logic synthesis, placement, and routing, interconnect synthesis plays an important role which includes buffer insertion/sizing and timing-driven routing. Although progress has been achieved by many advanced routing techniques, the following aspects
can be exploited sufficiently for further improvement: (1) incremental layer assignment for timing optimization; (2) signal routing with the requirement of regularity; (3) power-efficient optical-electrical interconnect paradigm. Thus, to perform the layer assignment and routing optimization for advanced technologies,
an automated routing engine in a global view is essential to benefit the interconnect design while satisfying specific requirements.
This dissertation proposes a set of algorithms and methodology on layer
assignment and routing optimization for advanced technologies. The research includes two timing-driven incremental layer assignment approaches, synergistic
topology generation and routing synthesis for signal groups, and optical-electrical routing design for power efficiency.
For incremental layer assignment, most of the conventional approaches
target via minimization but neglect the timing issues. Meanwhile, via delays
are ignored but should be considered in emerging technology nodes. Then two
timing-driven incremental layer assignment frameworks are proposed, where all the nets are solved simultaneously with the integration of via delays: (1) optimization of the total sum of net delays and reduction of slew violations; (2) minimization of critical path timing in selected nets.
For on-chip signal routing, the bundled bits in one group may have different
pin locations, but they have to be routed in a regular manner by sharing common topologies. Very few previous works target inter-bit regularity via multi-layer topology selection. Furthermore, the routability and wire-length of the signal bits should also be optimized. Then an advanced synergistic routing engine is promoted, which is able to not only control routability and wire-length but also guide each bit routing intelligently for design regularity.
For optical-electrical co-design routing, optical interconnect shows its
advantage due to the dominance of bandwidth-distance-power properties. The previous works lack a detailed exploration of optical-electrical co-design for on-chip interconnects. During the transmission, signal quality can be affected by various loss sources and Electrical to Optical (EO)/Optical to Electrical (OE) conversion overheads should also be considered. Then a power-efficient routing flow for on-chip signals is presented, where optical connections can collaborate with electrical wires seamlessly.
The effectiveness of proposed algorithms and techniques is demonstrated in this dissertation. These approaches are able to achieve the improvements regarding specific metrics and eventually benefit the routing flow.Electrical and Computer Engineerin
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