Managed information gathering and fusion for transient transport problems

This paper deals with vehicular traffic management by communication technologies from Traffic Control Center point of view in road networks. The global goal is to manage the urban traffic by road traffic operations, controlling and interventional possibilities in order to minimize the traffic delays and stops and to improve traffic safety on the roads. This paper focuses on transient transport, when the controlling management is crucial. The aim was to detect the beginning time of the transient traffic on the roads, to gather the most appropriate data and to get reliable information for interventional suggestions. More reliable information can be created by information fusion, several fusion techniques are expounded in this paper. A half-automatic solution with Decision Support System has been developed to help with engineers in suggestions of interventions based on real time traffic data. The information fusion has benefits for Decision Support System: the complementary sensors may fill the gaps of one another, the system is able to detect the changing of the percentage of different vehicle types in traffic. An example of detection and interventional suggestion about transient traffic on transport networks of a little town is presented at the end of the paper. The novelty of this paper is the gathering of information - triggered by the state changing from stationer to transient - from ad hoc channels and combining them with information from developed regular channels. --information gathering,information fusion,Kalman filter,transient traffic,Decision Support System

Formal Specification Language for Vehicular Ad-Hoc Networks

Vehicular Ad-Hoc Network (VANET) is a form of Mobile Ad-Hoc Network (wireless Network), originally used to provide safety & comfort for passengers, & currently being used to establish Dedicated Short Range Communications (DSRC) among near by Vehicles (V2V Communications) and between vehicles and nearby fixed infrastructure equipments; Roadside equipments (V2I Communications). VANET was used also to warn drivers of collision possibilities, road sign alarms, auto-payment at road tolls and parks. Usually VANET can be found in Intelligent Transportation Systems (ITS). VANET is the current and near future hot topic for research, that has been targeted by many researchers to develop some applications and protocols specifically for the VANET. But a problem facing all VANET researchers is the unavailability of a formal specification language to specify the VANET systems, protocols, applications and scenarios proposed by those researchers. A specification language is a formal language that is used during the systems design, analysis, and requirements analysis. Using a formal specification language, a researcher can show “What his system does”, Not How. As a contribution of our research we have created a formal specification language for VANET. We made the use of some Romans characters & some basic symbols to represent VANET Systems & Applications. In addition, we have created some combined symbols to represent actions and operations of the VANET system and its participating devices. Our formal specification language covers many of the VANET aspects, and offers Validity Test and Consistency Test for the systems. Using our specification language, we have presented three different case studies based on a VANET system model we have created and put them into the system validity and consistency tests and showed how to describe a VANET system and its applications using our formal specification language

Serviceorientiertes Mehrkanal-Beaconing in Fahrzeug-Ad-hoc-Netzen

The interconnection of vehicles is an important topic concerning the enhancement of traffic safety and trffic efficiency. Therefore, vehicles exchange position and state information with each other to establish an awareness level for the calculation of collision probabilities with their neighbors. To recognize critical safety situations it is essential to receive information reliably. However, these systems are typically based on wireless ad-hoc networks that cannot guarantee reliable packet transmission. This is especially the case in situations where a high number of communication nodes exist. The aim of this work at hand is the definition of a beaconing algorithm that enables the establishment of a desired awareness level for critical safety situations especially in high density traffic scenarios. First, representative scenarios for collision detection and collision avoidance were specified and metrics for the evaluation of the beaconing algorithms were defined. Based on these metrics the performance of beaconing algorithms with different static periodical update rates was evaluated. It is presented that these kinds of beaconing algorithms cannot provide sfficient results with respect to the required constant information throughput in high density traffic situations. To provide a high awareness level for each vehicle in its individual situation in spite of an unreliable communication channel a service-oriented beaconing approach is dened in this work. It is based on a request/response communication scheme to compensate particular packet loss. Hereby, a broadcast and a unicast occurrence of the algorithm are defined accordingly to the corresponding representative scenarios. It is presented that the service-oriented beaconing approach provides a signicant benefit with respect to the information throughput for low and middle traffic density situations. However, in high density situations the benefit of this approach is decreasing due to the increased communication overhead. This is a result of using one single communication channel. To achieve a high awareness level also in high density trac situations, a signi- cant modification was defined. Therefore, the usage of multiple communication channels was introduced to distribute the communication load over several channels. It is specified to send all service responses on a dedicated service channel to reduce the load on the control channel where the service requests are transmitted. After an extensive evaluation of the multi-channel utilization in vehicle ad-hoc networks using IEEE 802.11p it is shown that the multi-channel version of the service-oriented beaconing approach can achieve significant benefits concerning the information throughput for the collision detection and collision avoidance scenarios even in high density traffic situations.Die Vernetzung von Fahrzeugen untereinander ist ein wichtiger Aspekt im Hinblick auf die Erh�ohung der Verkehrssicherheit und -effizienz. Daf�ur tauschen Fahrzeuge mit ihren Nachbarn Positions- und Zustandsinformationen aus, um eine Wissensbasis zur Berechnung von Kollisionswahrscheinlichkeiten aufzubauen. Um kritische Situationen erkennen zu können, ist es notwendig, Informationen zuverl�assig empfangen zu können. Allerdings werden zur Umsetzung derartiger Systeme typischerweise WLAN-basierte Ad-hoc-Netze verwendet, welche vor allem bei einer hohen Anzahl an Teilnehmern keine zuverlässige Übertragung von Nachrichten gewährleisten. Ziel dieser Arbeit ist es, einen Beaconing-Algorithmus zu entwickeln, welcher es ermöglicht bei jeder Fahrzeugdichte die geforderte Wissensbasis zur Erkennung von sicherheitskritischen Situationen aufzubauen. Aufbauend auf der Spezifizierung der Situationen zur Kollisionserkennung und Kollisionsvermeidung und den damit definierten Metriken zur Beurteilung von Beaconing Algorithmen, wird zun�achst die Güte von Beaconing-Ansätzen mit unterschiedlichen statischen Beacon-Wiederholratn untersucht. Es wird gezeigt, dass dieser Ansatz die Anforderungen nach einem gleichbleibenden Informationsdurchsatz bei hohen Fahrzeugdichten nicht erfüllen kann. Um trotz der unzuverlässigen Nachrichtenübertragung den geforderten Informationsdurchsatz in Abhängigkeit der individuellen Situation eines jeden Fahrzeugs zu gew�ahrleisten, wird in dieser Arbeit ein serviceorientierter Beaconing-Ansatz eingeführt. Hierbei wird jeweils eine Variante für die entsprechende spezifizierte Situation definiert. Es wird gezeigt, dass der serviceorientierte Ansatz unter Nutzung von einem Kommunikationskanal bei niedrigen und mittleren Fahrzeugdichten eine Verbesserung des Informationsdurchsatzes erzielen kann. Bei hohen Fahrzeugdichten sinkt der Mehrwert allerdings aufgrund des hohen Nachrichtenaufkommens. Auf diesen Erkenntnissen wird eine Mehrkanal- Variante des Beaconing-Ansatzes vorgeschlagen. Hierbei sollen zur Serviceerbringung gesonderte Kan�ale genutzt werden, um die Kommunikationslast besser verteilen zu können. Nach einer ausgiebigen Evaluierung der Mehrkanalnutzung in Fahrzeuge-Ad-hoc-Netzen und unter Berücksichtigung der dabei existierenden Einschränkungen kann gezeigt werden, dass die Mehrkanal-Variante des serviceorientierten Beaconing-Ansatzes signifikante Verbesserungen für den Informationsdurchsatz sowohl in der Kollisionserkennungs- als auch Kollisionsvermeidungsphase über alle Fahrzeugdichten erzielen kann

Kontextbereitstellung in Automobilen Ad-hoc Netzen

Je detaillierter ein Fahrer über den Streckenabschnitt informiert ist, den er in naher Zukunft befahren wird, desto größer ist die Wahrscheinlichkeit, dass er rechtzeitig und angemessen auf komplexe Verkehrssituationen reagiert. Die umfassende Verfügbarkeit von qualitativ hochwertigen Kontextinformationen im Fahrzeug leistet vor diesem Hintergrund einen wichtigen Beitrag zur Erhöhung der Verkehrssicherheit und -effizienz. Ziel dieser Arbeit ist eine zuverlässige Vorhersage der zukünftigen Fahrsituation auf Basis des gemeinschaftlich bekannten Wissens der Verkehrsteilnehmer. Dabei steht die Verwaltung ortsbezogener Kontextinformationen, die Fusion von verschiedenartigen Informationsquellen, sowie die Problematik der Verteilung der von den Fahrzeugen erzeugten Kontextinformationen über automobile Ad-hoc Netzen im Fokus der Arbeit. Aufbauend auf einer formalen Lösungsspezifikation beschreibt die Arbeit einen zweistufigen Bewertungsprozess, der es erlaubt, auf Basis verteilter Sensorbeobachtungen unterschiedlicher Fahrzeuge ein Wahrscheinlichkeitsmaß für das Eintreten eines konkreten Zustands eines relevanten Fahrkontexts abzuleiten. Die räumlichen und zeitlichen Eigenschaften des Kontextaspekts werden dabei gewichtet interpoliert. Anschließend werden auf Basis eines Bayesschen Netzes die kausalen Zusammenhänge unterschiedlicher Kontextaspekte quervalidiert. Zudem wird aufgezeigt, wie Kontextinformationen zwischen Fahrzeugen in einem automobilen Ad-hoc Netzwerk ausgetauscht werden können. Das aus drahtgebundenen Netzen bekannte Konzept der Nutzenmaximierung des Netzwerks wird hierzu auf die speziellen Charakteristika automobiler Netze erweitert. Es wird zudem eine schichtenübergreifende Lösungsarchitektur vorgestellt, die situationsadaptiv sowohl kurze Latenzzeiten für kritische Nachrichten, als auch eine nachhaltige Skalierbarkeit des Netzes in Szenarien mit geringen und hohen Fahrzeugdichten sicherstellt. Der Kanalzugriff und die Verbreitung der Kontextinformationen im Netzwerk basieren dabei auf einer situationsabhängigen Bewertung des Anwendungsnutzens der zu übertragenden Nachrichten. Mit Hilfe von Simulationen wird das Verhalten des Systems bewertet. Durch eine ontologiebasierte Verwaltung wird auch nichtfahrzeugbezogenen Systemen eine domänenübergreifende Nutzung der Sensorinformationen und kausalen Zusammenhänge ermöglicht

Molecular phylogeny of horseshoe crab using mitochondrial Cox1 gene as a benchmark sequence

An effort to assess the utility of 650 bp Cytochrome C oxidase subunit I (DNA barcode) gene in delineating the members horseshoe crabs (Family: xiphosura) with closely related sister taxa was made. A total of 33 sequences were extracted from National Center for Biotechnological Information (NCBI) which include horseshoe crabs, beetles, common crabs and scorpion sequences. Constructed phylogram showed beetles are closely related with horseshoe crabs than common crabs. Scorpion spp were distantly related to xiphosurans. Phylogram and observed genetic distance (GD) date were also revealed that Limulus polyphemus was closely related with Tachypleus tridentatus than with T.gigas. Carcinoscorpius rotundicauda was distantly related with L.polyphemus. The observed mean Genetic Distance (GD) value was higher in 3rd codon position in all the selected group of organisms. Among the horseshoe crabs high GC content was observed in L.polyphemus (38.32%) and lowest was observed in T.tridentatus (32.35%). We conclude that COI sequencing (barcoding) could be used in identifying and delineating evolutionary relatedness with closely related specie

Crab and cockle shells as heterogeneous catalysts in the production of biodiesel

In the present study, the waste crab and cockle shells were utilized as source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shells are calcium carbonate which transformed into calcium oxide upon activated above 700 °C for 2 h. Parametric studies have been investigated and optimal conditions were found to be catalyst amount, 5 wt.% and methanol/oil mass ratio, 0.5:1. The waste catalysts perform equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to five times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity

A Framework for Network Utility Maximization in VANETs

A Framework for Network Utility Maximization in VANETs Vehicular Ad hoc Networks (VANETs) are expected to have great potential to improve both traffic safety and comfort in the future. Safety and traffic related applications will typically use broadcast-based communication schemes to disseminate messages within the network. Existing strategies to reduce redundant retransmissions and to improve reliability and efficiency of message dissemination rely on inflexible transmission limitations.They are not adequate to efficiently deal with the limited network resources efficiently both in sparse and in dense networks. Apart from that, they do not take into account the individual network nodes ’ interest in information. The goal of our concept is to provide network participants with data that has the highest utility for them with a latency as small as possible, independent of the actual network load. Our concept envisages the context-adaptive differentiation of data traffic according to current information relevance to allow for an optimal utilization of the limited network resources. In this paper, we propose methodologies for quantifying message relevance, present different mechanisms for realizing data prioritization and compare our solution with the IEEE 802.11e approach. 1