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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

DESIGN OF A CACC ASSISTANT FOR DAILY DEFENSIVE DRIVING

Gurram, Sriharsha 01 August 2019 (has links)
Automatic Vehicles is a possible future, but it does not mean that we should forget about improving the present day to day life. Most vehicles have Cruise Control, and few have Adaptive Cruise Control, but very few have Cooperative Adaptive Cruise Control(CACC) because it's an integration of software and hardware as different companies produce different vehicles it's hard to get on common ground. CACC at the core is communication among vehicles and sharing information; in this thesis, I tried to make it usable in any car with just the software used in a smartphone. As everybody has a phone in their hand with an inbuilt GPS, it is easier to use it directly rather than have a unique mechanical device embedded with a software application. My application gives the estimated speed usable at a particular time based on the other two vehicles, and it keeps changing based on other cars. It does not depend on any external sensors; hence, no environmental change can affect the data give by my vehicle. This application is a guide that could be used in the snow, rain, or hail when even eyes or technology cannot help. Location and speed are something, and using them and providing safety is my thesis all about.
2

HUMAN CLCA2 MODULATES THE CONDUCTANCE OF CALCIUM-ACTIVATED CHLORIDE CHANNELS BY REGULATION OF INTRACELLULAR CALCIUM

Sharma, Aarushi 01 August 2016 (has links)
Chloride channels play an essential role in the physiology of the respiratory system, the gastrointestinal tract, and secretory glands. Their dysregulation underlies debilitating pathologies such as cystic fibrosis, asthma, and certain cancers. The CLCA (Chloride Channel Accessory) gene family is thought to determine severity of these diseases by modulating an unidentified Calcium-activated Chloride Channel (CaCC). Recent evidence indicates Ano1 to be the mediator of strong quintessential calcium-activated chloride current in several cell types. Ano1 is highly expressed in airway epithelium and downregulated in cystic fibrosis patients. Human CLCA2 is also expressed in epithelium of airways and mammary glands, and there it promotes calcium-activated chloride current. Hence, we hypothesized that CLCA2 modulates the conductance of Ano1. We tested this by introducing Ano1 and CLCA2 together or separately into HEK293 cells, which express endogenous Ano1 at a low level. Using whole-cell voltage clamp, we found that CLCA2 enhanced the conductance of the endogenous CaCC. This current was inhibited by a specific inhibitor of Ano1, tannic acid. CLCA2 also increased both the amplitude and the onset rate of the Ano1-mediated current. To determine the mechanism by which CLCA2 amplifies Ano1 mediated current, we used co-immunoprecipitation with or without a protein cross-linking agent and to test whether the interaction if any, was stable or transient, respectively. Neither any interaction, nor any change in Ano1 multimerization was found. We next tested whether CLCA2 enhanced Ano1 conductance by increasing its stability or surface localization. Surface-labelling the cells expressing Ano1 alone or both proteins with biotin, no difference in Ano1 level or surface expression was detected. Ano1 has recently been shown to be activated by intracellular calcium released from endoplasmic reticulum (ER) stores and by subsequent store-operated calcium entry (SOCE). Therefore, we investigated whether CLCA2 could increase intracellular calcium levels. With Fluo-4 dye calcium imaging, we found that CLCA2 expression enhanced both ER calcium stores and SOCE upon exhaustion of intracellular stores, and the SOCE response could be abolished by a specific inhibitor of SOCE, BTP-2. This inhibitor also abolished CLCA2-induced chloride current, establishing that CLCA2 enhances CaCC via SOCE. Moreover, knockdown of CLCA2 in MCF10A cells, that naturally express both proteins, reduced both ER calcium stores and SOCE. Mutations that abolished the metalloprotease activity of CLCA2 or deleted the cytoplasmic tail had little effect on its enhancement of chloride current or intracellular calcium, suggesting that the uncleaved ectodomain was responsible for both effects of CLCA2. Since, the ectodomain is the most conserved region of the protein, we found that another member of the CLCA family, CLCA1, was also effective in enhancing intracellular calcium storage and SOCE. Co-immunoprecipitation studies further revealed that CLCA2 interacts in a ternary complex with mediators of SOCE, STIM1 and ORAI1. These results explain the CaCC-enhancing effects of CLCA family members and suggest a broader role in other calcium-dependent processes. Understanding the modulatory relationship between these molecules may lead to better therapies for airway diseases and Ano1-dependent cancers. Furthermore, the discovery that CLCA2 regulates intracellular calcium levels may explain its effects on cellular differentiation, stress response, and cell death.
3

Design and Implementation of Cooperative Adaptive Cruise Control

Mak, Spencer, Bjäde, Mattias January 2011 (has links)
With limited road infrastructure and increasing number of vehicles on the road, an intelligent transport system is needed to increase the throughput in traffic and minimize traffic jams in highly populated areas. The purpose of this project is to design and implement a control system that is capable of driving and following the preceding vehicle autonomously in the longitude direction only. The vehicle is also equipped with a vehicle to vehicle communication unit. With this information, all vehicles on the road can communicate with each other and are able to achieve shorter distances between vehicles and damp any disturbance caused by upstream traffic. A general structure on Cooperative Adaptive Cruise Control (CACC) is created by studying the research from The Netherlands Organization for Applied Scientific Research (TNO). A string stability criterion is used to determine if the system is suitable of driving in a platoon, where a string of vehicles are following a lead vehicle. This system is then implemented in a Volvo S60 and has participated in the 2011 Grand Cooperative Driving Challenge hosted in The Netherlands. The results show that the system has ability to increase throughput and damp disturbance on the upstream traffic by communicating with the other vehicles ahead. The system is also robust and simple enough to earn the 2nd place in the competition. / Grand Cooperative Driving Challenge
4

Network-wide Assessment of Eco-Cooperative Adaptive Cruise Control Systems on Freeway and Arterial Facilities

Tu, Ran 20 June 2016 (has links)
The environmental impact of a transportation system is critical in the assessment of the transportation system performance. Eco-Cooperative Adaptive Cruise Control (Eco-CACC) systems attempt to minimize vehicle fuel consumption and emission levels by controlling vehicle speed and acceleration levels. The majority of previous research efforts developed and applied Eco-CACC systems on either freeway or signalized intersections independently on simple and small transportation networks without consideration of the interaction among these controls. This thesis extends the state-of-the-art in Eco-CACC evaluation by conducting a comprehensive evaluation on a complex network considering Eco-CACC control on both freeways and arterials individually and simultaneously. The goal of this study is to compare Eco-CACCs on arterial facilities (Eco-CACC-A), freeway facilities (Eco-CACC-F) and both facilities (Eco-CACC-F+A). The effects of Eco-CACC are evaluated considering various Measures of Effectiveness (MOEs), including: average vehicle delay, fuel consumption, and emission levels using simulated results from INTEGRATION, a microscopic traffic assignment and simulation software, considering different freeway speed limits, traffic demand levels and system market penetration rates. In total, 19 traffic scenarios for each of the four different cases (Eco-CACC-A, Eco-CACC-F and Eco-CACC-F+A plus a base no control case) were tested. In total 760 simulation runs were conducted (4 cases * 19 scenarios * 10 repetitions). T-tests and pairwise mean comparison (Tukey HSD) were conducted to identify any statistical differences between control cases and the base case from the simulation results. This thesis shows that arterial and freeway Eco-CACCs can work well together and their effects will be largely influenced by network characteristics. / Master of Science
5

Investigating Attacks on Vehicular Platooning and Cooperative Adaptive Cruise Control / Undersökning av attacker på fordonståg och kollaborativ adaptiv farthållning

Kalogiannis, Konstantinos January 2020 (has links)
Autonomous vehicles are a rising technology that aims to change the way people think about mobility in the future. A crucial step towards that goal is the assurance that malicious actors cannot instigate accidents that could lead to damages or loss of life. Currently, vehicle platoons, that is vehicles cooperating together to increase fuel saving and driver comfort, are used in limited environments and are the focus of research aimed to make them suitable for real-world wide usage. In that regard, guaranteeing that the vehicle is able to operate alongside other entities, autonomous or not, in the traditional sense is not adequate. The computer systems involved can be the target or the source of a malicious act without the knowledge of the operator in either case. In the context of platooning, these acts can have devastating effects and can originate either from other vehicles on the road or from within, from compromised vehicles that are part of the formation. In this thesis, the focus is centered around the latter. We investigate jamming and data falsification attacks that aim to either destabilize the platoon, thus, reducing its benefits or provoke an accident. These attacks are more difficult to discern and will range from simple falsification attacks to more complex ones that aim to bypass defensive mechanisms. In that sense, we direct our experiments against the platoon maneuvers that are a core functionality of platooning and are required for its nominal operation. The results of this analysis show that several attacks can lead to accidents with position falsification being the most productive. It is also demonstrated that a malicious leader can pose a serious threat to the viability of the platoon because of his unique capability of interacting with all the platoon members. Attacks during the platoon maneuvers are demonstrated to pose a threat, not only to the stability of the formation but also the nature of the platooning application itself. This is achieved by effectively isolating the platoon from potential joiners. / Självkörande fordon är en framväxande teknologi med mål att ändra människors framtida inställning till mobilitet. Ett kritiskt steg mot målet är att försäkra sig om att aktörer med ont uppsåt inte kan orsaka olyckor som kan leda till skador eller dödsfall. För närvarande används fordonståg, alltså fordon som samarbetar för att minska bränsleförbrukning och öka körkomfort, i avgränsade miljöer med fokus på att anpassa dessa för verklig användning. Att garantera att fordonet kan köras tillsammans med andra enheter är då inte tillräckligt eftersom dessa system kan bli mål för externa och interna attacker som kan ha förödande konsekvenser. Denna uppsats fokuserar på det senare fallet och undersöker interna datafalsifierings- och frekvensstörningsattacker avsedda att destabilisera fordonståg i syfte att minska deras fördelar eller provocera fram en olycka. Dessa attacker är svåra att urskilja och inkluderar allt från enkla falsifikationsattacker till komplexa attacker som syftar till att kringgå specifika försvarsmekanismer. Med det i åtanke inriktar vi våra experiment mot de manövrar som är en del av fordonstågens grundfunktionalitet och krävs för deras nominella drift. Resultaten av arbetet visar att under fordonstågmanövrar så kan flertalet av de utvärderade attackerna orsaka olyckor och att attacker genom förfalskning av position var speciellt förödande. Vi har även påvisat att en fordonstågsledare med ont uppsåt utgör ett speciellt allvarligt hot mot fordonstågets funktionalitet på grund av dennes unika möjlighet att interagera med alla medlemmar. Attacker under manövrar har visats utgöra ett hot, inte bara mot stabiliteten av formationen, men även mot de grundläggande egenskaperna hos systemet själv såsom att isolera fordonståget från nya medlemmar.
6

Eco-cooperative adaptive cruise control at multiple signalized intersections

Almutairi, Fawaz 30 January 2017 (has links)
Consecutive traffic signals produce vehicle stops and acceleration/deceleration maneuvers on arterial roads, which may increase vehicle fuel consumption levels significantly. Eco-cooperative adaptive cruise control (Eco-CACC) systems can improve vehicle energy efficiency using connected vehicle (CV) technology. In this thesis, an Eco-CACC system is proposed to compute a fuel-optimized vehicle trajectory while traversing multiple signalized intersections. The proposed system utilizes signal phasing and timing (SPaT) information together with real-time vehicle dynamics data to compute the optimal acceleration/deceleration levels and cruise speeds for connected-technology-equipped vehicles while approaching and leaving signalized intersections, while considering vehicle queues upstream of the intersections. The INTEGRATION microscopic traffic simulation software was used to conduct a comprehensive sensitivity analysis of a set of variables, including different levels of CV market penetration rates (MPRs), demand levels, phase splits, offsets, and distances between intersections to assess the benefits of the proposed algorithm. Based on the analysis, fuel consumption saving increase with an increase in MPRs and a decrease in the cycle length. At a 100% equipped-vehicle MPR, the fuel consumption is reduced by as much as 13.8% relative to the base no Eco-CACC control. The results demonstrate an existence of optimal values for demand levels and the distance between intersections to reach the maximum fuel consumption reduction. Moreover, if the offset is near the optimal values for that specific approach, the benefits from the algorithm are reduced. The algorithm is limited to under-saturated conditions, so the algorithm should be enhanced to deal with over-saturated conditions. / Master of Science / Consecutive traffic signals produce vehicle stops and acceleration/deceleration maneuvers on arterial roads, increasing vehicle fuel consumption levels. Drivers approaching signals are unaware of the signal status and may accelerate/decelerate aggressively to respond to traffic signal indications and thus increasing their fuel consumption. Research has been conducted to provide the driver with an optimal speed recommendations to reduce fuel consumption. Connected vehicle (CV) technology can be used to create a communication between the vehicle and traffic signals to provide information about the traffic light status and how many vehicles are waiting in the queue. In this thesis, an Eco-cooperative adaptive cruise control (Eco-CACC) system is proposed, which is a system that uses signal information to provide speed advice to the driver. This speed advice will not make the vehicle stop at any intersection, and this will reduce fuel consumption levels. The INTEGRATION software was used to test the effectiveness of the system in many scenarios. These scenarios include how many vehicles are equipped with this system, how many vehicles are in the system, the length of the green interval of the traffic signal, and distance between intersections. If we equip all vehicles with the system, the savings in fuel consumption can reach up to 13.8%. The system is designed for a network that is not extremely congested (over-saturated), implying that queues dissipate in a single traffic light cycle. The system needs to be further developed to deal with over-saturated conditions.
7

Influ?ncia da taxa de resfriamento na microestrutura da fase quasicristalina na liga Al65Cu35-xFex com baixo teor de Fe solidificada fora do equil?brio

Piedade, Luiz Alberto Silva da 18 August 2017 (has links)
Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2017-10-26T16:09:28Z No. of bitstreams: 1 Tese Eng. Piedade.pdf: 6225051 bytes, checksum: c7f77823a538300959734acada65a861 (MD5) / Rejected by Caroline Xavier (caroline.xavier@pucrs.br), reason: Devolvido devido a 1) Arquivo PDF sem capa institucional. 2) Na primeira e segunda folha do arquivo PDF, o nome do autor est? incompleto. Na ficha catalogr?fica e publica??o enviada est? completo. 3) Nome e descri??o do arquivo na publica??o est?o em desacordo com o manual enviado. on 2017-11-07T13:03:14Z (GMT) / Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2017-11-08T17:01:40Z No. of bitstreams: 1 final para entrega com capa.pdf: 6291908 bytes, checksum: a447082574d55fe4709b55f1c2da38fb (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-11-17T12:16:13Z (GMT) No. of bitstreams: 1 final para entrega com capa.pdf: 6291908 bytes, checksum: a447082574d55fe4709b55f1c2da38fb (MD5) / Made available in DSpace on 2017-11-17T12:20:52Z (GMT). No. of bitstreams: 1 final para entrega com capa.pdf: 6291908 bytes, checksum: a447082574d55fe4709b55f1c2da38fb (MD5) Previous issue date: 2017-08-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Quasicrystals are materials that have unusual characteristics, they can not be described as crystalline, for not having long-range order, or as amorphous, have medium-range structure. Some Al-Cu-Fe family alloys presents quasicrystalline phases when have rapidly solidification. In order to obtain this alloy, ingots of the Al65Cu35-xFex family were casted with x=6 (atomic), initially in a standard mold with solidification equilibrium. To provide samples with different cooling rates, the alloy was cast in a stepped mold, containing six different steps, resulting in samples out of equilibrium state (rapidly solidification). For the analysis of the cooling curves, the CACC-TA technique was used, with cooling rates varying from170 to 540?C / s, which were obtained by dT/dt. Analyzes by optical microscopy, scanning electron microscopy (SEM), dispersive energy spectrometry (EDS), show microstructure with faceted dendrites, lamellar interdendritic formations and pentagonal precipitates (IQC). The Vickers microhardness ranged from 4.09 to 7.22 GPa and the X-ray diffraction (XRD) proved by characteristic diffractograms the icosahedral quasicrystalline phase formation. / Os quasicristais s?o materiais que apresentam caracter?sticas incomuns, pois n?o podem ser descritos como cristalinos, por n?o apresentarem ordem de longo alcance, nem como amorfos, apresentam estrutura de m?dio alcance. Algumas ligas da fam?lia Al-Cu-Fe apresentam fases quasicristalinas quando rapidamente solidificadas. Para obter-se esta liga, foram fundidos lingotes da fam?lia Al65Cu35-xFex com x=6 (at?mico), inicialmente em um molde padr?o com solidifica??o em estado de equil?brio. Para proporcionar amostras com taxas de resfriamento variadas, a liga foi vazada em um molde escalonado, contendo seis cavidades diferentes, resultando em amostras solidificadas fora do estado de equil?brio (solidifica??o r?pida). Para an?lise das curvas de resfriamento utilizou- se a t?cnica CACC-TA, com taxas de resfriamento variando entre 170 e 540?C/s, que foram obtidas por meio de dT/dt. An?lises por microscopia ?ptica, microscopia eletr?nica de varredura (MEV), espectrometria por energia dispersiva (EDS), mostram microestrutura com dendritas facetadas, forma??es interdendr?ticas lamelares e precipitados pentagonais (IQC). A microdureza Vickers variou entre 417 HV e 736 HV (4,09 e 7,22 GPa) e a difra??o de raios X (DRX) comprovou por meio de difratogramas caracter?sticos a forma??o de fase quasicristalina icosa?drica.
8

Evolution Of The Cicekdagi Basin, Central Anatolia, Turkey

Gulyuz, Erhan 01 December 2009 (has links) (PDF)
&Ccedil / i&ccedil / ekdagi basin developed on the Central Anatolian Crystalline Complex (CACC) is a foreland basin developed as the southern integral part of the &Ccedil / ankiri Basin during the Late Paleocene to middle Oligocene. The basin has two compartments separated by the &Ccedil / i&ccedil / ekdagi High comprises two sedimentary cycles. The oldest cycle comprises Barakli, Koca&ccedil / ay and Bogazk&ouml / y formationsa and is exposed both in the northern and the southern sectors. They were deposited in marine conditions. The second cycle comprises incik and G&uuml / vendik formations and was deposited in continental settings. The first cycle comprises uniformly south-directed paleocurrent directions in both the northern and southern sectors whereas the second cycle deposits are represented by south-directed directions in the southern sector, and bimodal directions in the northern sector. In addition, the second cycle formations contain progressive unconformities and coarsening upwards sequences indicative of thrusting. Internal structures of the units and paleostress data indicate that the basin experienced over-all compression and local extension due to flexural bending. This gave way to inversion of some of the normal faults and uplift of the &Ccedil / i&ccedil / ekdagi High during the deposition of second cycle in the Late Eocene to middle Oligocene time which subsequently resulted in compartmentalization of the basin.
9

Analyse de Performances de Régulateurs de Vitesse Adaptatifs Coopératifs / Cooperative Adaptive Cruise Control Performance Analysis

Sun, Qi 15 December 2016 (has links)
Cette thèse est consacrée à l'analyse de performance de Régulateurs de Vitesse Adaptatifs Coopératifs(CACC) pour un train de véhicules intelligents afin de réduire la congestion du trafic et améliorer la sécurité routière.Premièrement, la politique d'espacement, à Intervalles Constants de Temps (CTH) est introduite. Basé sur cette politique d'espacement, un nouveau système décentralisé de Deux-Véhicules-Devant CACC (TVACACC) est proposé, dans lequel l'accélération souhaitée de deux véhicules précédents est prise en compte. Ensuite, la stabilité de la chaîne du système proposé est analysée théoriquement. Il est démontré que grâce à l'aide de la communication multiple entre véhicules, une meilleure stabilité de la chaîne est obtenue par rapport au système conventionnel. Un train de véhicules dans le scénario Stop-and-Go est simulé avec une communication parfaite puis dégradée. Le système proposé donne un comportement stable de la chaîne, correspondant à l'analyse théorique.Deuxièmement, une technique de dégradation pour CACC est présentée comme stratégie alternative lorsque la communication sans fil est partiellement ou complètement perdue. La stratégie proposée, appelée DTVACACC, utilise le filtre de Kalman pour estimer l'accélération actuelle du véhicule précédent qui remplace l'accélération souhaitée. Il est démontré que la performance pour le DTVACACC, peut être maintenue à un niveau beaucoup plus élevé.Enfin, une approche d’Apprentissage par Renforcement (RL) pour système CACC est proposée. L' algorithme politique- gradient est introduit pour réaliser le contrôle longitudinal . Ensuite, la simulation a montré que cette nouvelle approche de RL est efficace pour CACC / This PhD thesis is dedicated to the performance analysis of Cooperative Adaptive Cruise Control (CACC) system for intelligent vehicle platoon with the main aims of alleviating traffic congestion and improving traffic safety. At first, the Constant Time Headway (CTH) spacing policy for vehicle platoon is introduced. Based on this spacing policy, a novel decentralized Two-Vehicle-Ahead CACC (TVACACC) system is proposed, in which the desired acceleration of two front vehicles is taken into account. Then the string stability of the proposed system is theoretically analyzed. It is shown that by using the multiple wireless communication among vehicles, a better string stability is obtained compared to the conventional system. Vehicle platoon in Stop-and-Go scenario is simulated with both normal and degraded communication.Secondly, a graceful degradation technique for CACC was presented, as an alternative fallback strategy when wireless communication is lost or badly degraded. The proposed strategy, which is referred to DTVACACC, uses Kalman filter to estimate the preceding vehicle’s current acceleration as a replacement of the desired acceleration. It is shown that the performance is maintained at a much higher level.Finally, a Reinforcement Learning (RL) approach of CACC system is proposed. The policy-gradient algorithm is introduced to achieve the longitudinal control. Then simulation has shown that this new RL approach results in efficient performance for CACC.

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