Evaluation of the effects of different groove length and thickness of the retainers on the retention of maxillary anterior base metal resin bonded retainers ' an in vitro study

Objectives: The resin-bonded fixed partial dentures have gained immense popularity in recent years as they are more conservative, esthetic, economic and easily fabricated. However debonding is considered the most common cause of failure of resin bonded prosthesis. The objective of the study were to compare the effects of different groove lengths and thickness of retainers on retention of maxillary anterior base metal resin bonded retainers. Study Design: Twenty five metal dies of maxillary central incisor duplicated from pure typhodont teeth (maxillary left central incisors) prepared to receive retainer for resin bonded fixed partial denture having different test designs were made. Five test groups were made with each group having five specimens. Two groups were having preparation depth of 0.5mm and retention groove lengths of 3mm and 5mm. Two groups had preparation depths of 0.3 and 0.7mm with no groove preparation with retainer thickness of 0.3 and 0.7mm respectively. Fifth group with no groove preparation and preparation depth of 0.5mm was kept as control for all the groups. All the specimens were cemented using calibra (Dentsply) resin cement. Each specimen was subjected to tensile loading in vertical direction on universal testing machine (Instron 5569) at a crosshead speed of 1mm/min. \ Results: Groups with 5mm and 3mm groove length recorded higher mean vertical forces when compared to the group with no groove preparation. Group with 5mm groove length showed highest mean vertical forces. The group with 0.7mm retainer recorded higher mean vertical force values when compared to groups with 0.5mm and 0.3mm retainer thickness. Group with 0.3mm retainer thickness recorded the least mean vertical force value. Conclusion: Placement of the grooves increased the retention values almost 2 ½ times than the grooveless preparation and as the thickness of the retainers increased retention values also increased. Retention value was directly proportional to the groove length and retainer thickness

Algorithms and techniques for transitioning to software defined networks

Software Defined Networking (SDN) has seen growing deployment in the large wired data center networks due to its advantages like better network manageability and higherlevel abstractions. At the core of SDN is the separation and centralization of the control plane from the forwarding elements in the network as opposed to the distributed control plane of current networks. However various issues need to be addressed for an efficient transition to SDN from existing legacy networks. In this thesis, we address following three important challenges in this regards. (1) The task of deploying the distributed controllers continues to be performed in a manual and static way. To address this problem, we present a novel approach called InitSDN to bootstrapping the distributed software defined network architecture and deploying the distributed controllers. (2) Data center networks (DCNs) rely heavily on the use of group communications for various tasks such as management utilities, collaborative applications, distributed databases, etc. SDN provides new opportunities for re-engineering multicast protocols that can address current limitations with IP multicast. To that end we present a novel approach to using SDN-based multicast (SDMC) for flexible, network load-aware, and switch memory-efficient group communication in DCNs. (3) SDN has been slow to be used in the wireless scenario like wireless mesh networks (WSN) compared to wired data center networks. This is due to the fact that SDN (and its underlying OpenFlow protocol) was designed initially to run in the wired network where SDN controller has wired access to all the switches in the network. To address this challenge, we propose a pure opneflow based approach for adapting SDN in wireless mesh netowrks by extending current OpenFlow protocol for routing in the wireless network

A FORMAL LANGUAGE APPROACH FOR DETECTING TEXTURE PATHS AND PATTERNS IN IMAGES

This Master thesis considers the use of formal languages representation for image processing, especially texture patterns and determining texture paths in them. The texture paths are detected and extracted by using image processing techniques, such as image segmentation to isolate regions of interest, and then the extraction of repeating textures. The detection of the texture blocks is obtained by recursively using 27 X 27, 9 X 9, and 3 X 3 windows. Predefined repeating texture patterns are also searched for in each of the sets. For each set of texture blocks with similar or same characteristics, curve fitting techniques are used for association of patterns with the texture. The selected curve is split into straight line segments, and the pattern is finally represented using the defined context-free formal language methodology. Results are shown for various color images

Maximizing Vehicular Network Connectivity through an Effective Placement of Road Side Units Using Voronoi Diagrams

Vehicular Ad-hoc Networks (VANETs) are increasingly used to support critical services that improve traffic safety and alleviate traffic congestion. Developing VANET-based services and applications, however, is hindered due primarily to limited and often fluctuating communication capacity of VANETs that stem from the wireless and mobile nature of vehicle-tovehicle (V2V) communications. To address this limitation, Road- Side Units (RSU) have been proposed to complement V2V communication by providing event and data brokering capability in the form of Vehicle-to-Infrastructure (V2I) communications. This paper proposes a novel Voronoi network-based algorithm for the effective placement of RSU's which when deployed forms Voronoi networks in terms of the amount of delay incurred by data packets sent over the RSUs

Performance Trade-Offs In A Parallel Test Generation/ Fault Simulation Environment

As parallel processing hardware becomes more common and affordable, multiprocessors are being increasingly used to accelerate VLSI CAD algorithms. The problem of partitioning faults in a parallel test generation/ fault simulation (TG/FS) environment has received very little attention in the past. In a parallel TG/FS environment, the fault partitioning method used can have a significant impact on the overall test length and speedup. We propose heuristics to partition faults for parallel test generation with minimization of both the overall run time and test length as an objective. Also, for efficient utilization of available processors, the work load has to be balanced at all times. Since it is very difficult to predict a priori how difficult it is to generate a test for a particular fault, we propose a load balancing method which uses static partitioning initially and then uses dynamic allocation of work for processors which become idle. We present a theoretical model to predict the pe..

Improving the Reliability and Availability of Vehicular Communications Using Voronoi Diagram-Based Placement of Road Side Units

Vehicular Ad-hoc Networks (VANETs) form the basis for critical services that improve traffic safety and alleviate traffic congestion. The reliability of VANET-based services and applications that are based solely on vehicle-to-vehicle (V2V) communications, however, is hindered due primarily to limited and often fluctuating V2V communications. To address this limitation, Road-Side Units (RSU) have been proposed to complement V2V communications by providing stable event and data brokering capability. Effective placement of the RSUs is a key requirement in improving reliability of VANET services. This poster describes a novel Voronoi network-based algorithm for the effective placement of RSUs. The reliability metric considered in placing the RSUs involves bounding both the delay incurred by communication packets and packet loss, which in turn ensure timeliness and correct operation of the VANET services

Voronoi-based placement of road-side units to improve dynamic resource management in Vehicular Ad Hoc Networks

Vehicular Ad-hoc Networks (VANETs) illustrate mobile P2P networks, which hold significant promise in improving traffic safety and alleviating traffic congestion. Reliable VANETbased services require dynamic resource management due to limited and often fluctuating network connectivity of VANETs that stem from the wireless and mobile nature of vehicleto-vehicle (V2V) communications. To address these needs, a collaboration with Road-Side Units (RSU) have been proposed to complement V2V communication by providing event and data brokering capability in the form of Vehicle-to-Infrastructure (V2I) communications. Deploying RSUs involves upfront investment and maintenance costs, and hence solutions are needed that maximize the benefit of RSUs by placing them effectively in accordance to existing and projected traffic density, and the types of services planned for VANETs. To address these challenges, this paper proposes a novel Voronoi diagram-based algorithm for the effective placement of RSUs using packet delay and loss as a criteria. This approach has two-fold advantages: a significant reduction in the number of RSUs required to cover a geographic region, and increase in the logical coverage area of each RSU irrespective of the dynamic vehicular traffic conditions thereby improving reliability of communications. This algorithm has been evaluated in the context of a road network and traffic conditions for an urban area. When compared with other baseline placement algorithms, communication reliability stemming from our Voronoi diagram-based placement algorithm results in less packet delay and lesser packet loss both of which are important to realize the different VANET-based services

A Parallel Branch And Bound Algorithm For Test Generation

For circuits of VLSI complexity, test generation time can be prohibitive. Most of the time is consumed by hard-to-detect (HTD) faults which might remain undetected even after a large number of backtracks. We identify the problems inherent in a uniprocessor implementation of a test generation algorithm and propose a parallel test generation method which tries to achieve a high fault coverage for HTD faults in a reasonable amount of time. A dynamic search space allocation strategy is proposed which allocates disjoint search spaces to minimize the redundant work.The search space allocation strategy tries to utilize the partial solutions generated by other processors to increase the probability of searching in a solution area. The parallel test generation algorithm has been implemented on an Intel iPSC/2 hypercube. Results are presented using the ISCAS benchmark circuits which conclusively prove that parallel processing of HTD faults does indeed result in high fault coverage which is other..

Third world legal studies : an annual publ. of the International Third World Legal Studies Association

International audienceTo improve reliability and performance of Software Defined Networking (SDN) architectures, a number of recent efforts have proposed a logically centralized but physically distributed controller design that overcomes the bottleneck introduced by a single physical controller. Despite these advances, two key problems still persist. First, the task of controlling the host network and the task of controlling the control-plane network remain tightly intertwined, which incurs unwanted complexity in the controller design. Second, the task of deploying the distributed controllers continues to be performed in a manual and static way. To address these two problems, this paper presents a novel approach called InitSDN to bootstrapping the distributed software defined network architecture and deploying the distributed controllers. InitSDN makes the SDN control plane design less complex, makes coordination among controllers flexible, provides additional reliability to the distributed control plane