The Complexity of Splay Trees and Skip Lists

Magister Scientiae - MScOur main results are that splay trees are faster for sorted insertion, where AVL trees are faster for random insertion. For searching, skip lists are faster than single class top-down splay trees, but two-class and multi-class top-down splay trees can behave better than skip lists.South Afric

Computer Aided Verification

This open access two-volume set LNCS 13371 and 13372 constitutes the refereed proceedings of the 34rd International Conference on Computer Aided Verification, CAV 2022, which was held in Haifa, Israel, in August 2022. The 40 full papers presented together with 9 tool papers and 2 case studies were carefully reviewed and selected from 209 submissions. The papers were organized in the following topical sections: Part I: Invited papers; formal methods for probabilistic programs; formal methods for neural networks; software Verification and model checking; hyperproperties and security; formal methods for hardware, cyber-physical, and hybrid systems. Part II: Probabilistic techniques; automata and logic; deductive verification and decision procedures; machine learning; synthesis and concurrency. This is an open access book

Fast, Scalable, and Flexible C++ Hardware Architectures for Network Data Plane Queuing and Traffic Management

Les réseaux de communication actuels et ceux de la prochaine génération font face à des défis majeurs en matière de commutation et de routage de paquets dans le contexte des réseaux définis par logiciel (SDN–Software Defined Networking), de l’augmentation du trafic provenant des diffèrents utilisateurs et dispositifs connectés, et des exigences strictes de faible latence et haut débit. Avec la prochaine technologie de communication, la cinquième génération (5G) permettra des applications et services indispensables tels que l’automatisation des usines, les systèmes de transport intelligents, les réseaux d’énergie intelligents, la chirurgie à distance, la réalité virtuelle/augmentée, etc. Ces services et applications exigent des performances très strictes en matière de latence, de l’ordre de 1 ms, et des débits de données atteignant 1 Gb/s. Tout le trafic Internet transitant dans le réseau est traité par le plan de données, aussi appelé traitement associé au chemin dit d’accès rapide. Le plan de données contient des dispositifs et équipements qui gèrent le transfert et le traitement des différents trafics. La hausse de la demande en bande passante Internet a accru le besoin de processeurs plus puissants, spécialement conçus pour le traitement rapide des paquets, à savoir les unités de traitement réseau ou les processeurs de réseau (NPU–Network Processing Units). Les NPU sont des dispositifs de réseau pouvant couvrir l’ensemble du modèle d’interconnexion de systèmes ouverts (OSI–Open Systems Interconnect) en raison de leurs capacités d’opération haute vitesse et de fonctionnalités traitant des millions de paquets par seconde. Compte tenu des besoins en matière de haut débit sur les réseaux actuels, les NPU doivent accélérer les fonctionnalités de traitement des paquets afin d’atteindre les requis des réseaux actuels et pour pouvoir supporter la nouvelle génération 5G. Les NPU fournissent divers ensembles de fonctionnalités, depuis l’analyse, la classification, la mise en file d’attente, la gestion du trafic et la mise en mémoire tampon du trafic réseau.----------ABSTRACT: Current and next generation networks are facing major challenges in packet switching and routing in the context of software defined networking (SDN), with a significant increase of traffic from different connected users and devices, and tight requirements of high-speed networking devices with high throughput and low latency. The network trend with the upcoming fifth generation communication technology (5G) is such that it would enable some desired applications and services such as factory automation, intelligent transportation systems, smart grid, health care remote surgery, virtual/augmented reality, etc. that require stringent performance of latency in the order of 1 ms and data rates as high as 1 Gb/s. All traffic passing through the network is handled by the data plane, that is called the fast path processing. The data plane contains networking devices that handles the forwarding and processing of the different traffic. The request for higher Internet bandwidth has increased the need for more powerful processors, specifically designed for fast packet processing, namely the network processors or the network processing units (NPUs). NPUs are networking devices which can span the entire open systems interconnection (OSI) model due to their high-speed capabilities while processing millions of packets per second. With the high-speed requirement in today’s networks, NPUs must accelerate packet processing functionalities to meet the required throughput and latency in today’s networks, and to best support the upcoming next generation networks. NPUs provide various sets of functionalities, from parsing, classification, queuing, traffic management, and buffering of the network traffic. In this thesis, we are mainly interested in the queuing and traffic management functionalities in the context of high-speed networking devices. These functionalities are essential to provide and guarantee quality of service (QoS) to various traffic, especially in the network data plane of NPUs, routers, switches, etc., and may represent a bottleneck as they reside in the critical path. We present new architecures for NPUs and networking equipment. These functionalities are integrated as external accelerators that can be used to speed up the operation through field-programmable gate arrays (FPGAs). Also, we aim to propose a high-level coding style that can be used to solve the optimization problems related to the different requirement in networking that are parallel processing, pipelined operation, minimizing memory access latency, etc., leading to faster time-to-market and lower development efforts from high-level design in comparison to hand-written hardware description language (HDL) coded designs

Data Bandwidth Reduction Techniques For Distributed Embedded Simulatio

Maintaining coherence between the independent views of multiple participants at distributed locations is essential in an Embedded Simulation environment. Currently, the Distributed Interactive Simulation (DIS) protocol maintains coherence by broadcasting the entity state streams from each simulation station. In this dissertation, a novel alternative to DIS that replaces the transmitting sources with local sources is developed, validated, and assessed by analytical and experimental means. The proposed Concurrent Model approach reduces the communication burden to transmission of only synchronization and model-update messages. Necessary and sufficient conditions for the correctness of Concurrent Models in a discrete event simulation environment are established by developing Behavioral Congruence ¨B(EL, ER) and Temporal Congruence ¨T(t, ER) functions. They indicate model discrepancies with respect to the simulation time t, and the local and remote entity state streams EL and ER, respectively. Performance benefits were quantified in terms of the bandwidth reduction ratio BR=N/I obtained from the comparison of the OneSAF Testbed Semi-Automated Forces (OTBSAF) simulator under DIS requiring a total of N bits and a testbed modified for the Concurrent Model approach which required I bits. In the experiments conducted, a range of 100 d BR d 294 was obtained representing two orders of magnitude reduction in simulation traffic. Investigation showed that the models rely heavily on the priority data structure of the discrete event simulation and that performance of the overall simulation can be enhanced by an additional 6% by improving the queue management. A low run-time overhead, self-adapting storage policy called the Smart Priority Queue (SPQ) was developed and evaluated within the Concurrent Model. The proposed SPQ policies employ a lowcomplexity linear queue for near head activities and a rapid-indexing variable binwidth calendar queue for distant events. The SPQ configuration is determined by monitoring queue access behavior using cost scoring factors and then applying heuristics to adjust the organization of the underlying data structures. Results indicate that optimizing storage to the spatial distribution of queue access can decrease HOLD operation cost between 25% and 250% over existing algorithms such as calendar queues. Taken together, these techniques provide an entity state generation mechanism capable of overcoming the challenges of Embedded Simulation in harsh mobile communications environments with restricted bandwidth, increased message latency, and extended message drop-outs

Configuration Management of Distributed Systems over Unreliable and Hostile Networks

Economic incentives of large criminal profits and the threat of legal consequences have pushed criminals to continuously improve their malware, especially command and control channels. This thesis applied concepts from successful malware command and control to explore the survivability and resilience of benign configuration management systems. This work expands on existing stage models of malware life cycle to contribute a new model for identifying malware concepts applicable to benign configuration management. The Hidden Master architecture is a contribution to master-agent network communication. In the Hidden Master architecture, communication between master and agent is asynchronous and can operate trough intermediate nodes. This protects the master secret key, which gives full control of all computers participating in configuration management. Multiple improvements to idempotent configuration were proposed, including the definition of the minimal base resource dependency model, simplified resource revalidation and the use of imperative general purpose language for defining idempotent configuration. Following the constructive research approach, the improvements to configuration management were designed into two prototypes. This allowed validation in laboratory testing, in two case studies and in expert interviews. In laboratory testing, the Hidden Master prototype was more resilient than leading configuration management tools in high load and low memory conditions, and against packet loss and corruption. Only the research prototype was adaptable to a network without stable topology due to the asynchronous nature of the Hidden Master architecture. The main case study used the research prototype in a complex environment to deploy a multi-room, authenticated audiovisual system for a client of an organization deploying the configuration. The case studies indicated that imperative general purpose language can be used for idempotent configuration in real life, for defining new configurations in unexpected situations using the base resources, and abstracting those using standard language features; and that such a system seems easy to learn. Potential business benefits were identified and evaluated using individual semistructured expert interviews. Respondents agreed that the models and the Hidden Master architecture could reduce costs and risks, improve developer productivity and allow faster time-to-market. Protection of master secret keys and the reduced need for incident response were seen as key drivers for improved security. Low-cost geographic scaling and leveraging file serving capabilities of commodity servers were seen to improve scaling and resiliency. Respondents identified jurisdictional legal limitations to encryption and requirements for cloud operator auditing as factors potentially limiting the full use of some concepts

Systematic Approaches for Telemedicine and Data Coordination for COVID-19 in Baja California, Mexico

Conference proceedings info: ICICT 2023: 2023 The 6th International Conference on Information and Computer Technologies Raleigh, HI, United States, March 24-26, 2023 Pages 529-542We provide a model for systematic implementation of telemedicine within a large evaluation center for COVID-19 in the area of Baja California, Mexico. Our model is based on human-centric design factors and cross disciplinary collaborations for scalable data-driven enablement of smartphone, cellular, and video Teleconsul-tation technologies to link hospitals, clinics, and emergency medical services for point-of-care assessments of COVID testing, and for subsequent treatment and quar-antine decisions. A multidisciplinary team was rapidly created, in cooperation with different institutions, including: the Autonomous University of Baja California, the Ministry of Health, the Command, Communication and Computer Control Center of the Ministry of the State of Baja California (C4), Colleges of Medicine, and the College of Psychologists. Our objective is to provide information to the public and to evaluate COVID-19 in real time and to track, regional, municipal, and state-wide data in real time that informs supply chains and resource allocation with the anticipation of a surge in COVID-19 cases. RESUMEN Proporcionamos un modelo para la implementación sistemática de la telemedicina dentro de un gran centro de evaluación de COVID-19 en el área de Baja California, México. Nuestro modelo se basa en factores de diseño centrados en el ser humano y colaboraciones interdisciplinarias para la habilitación escalable basada en datos de tecnologías de teleconsulta de teléfonos inteligentes, celulares y video para vincular hospitales, clínicas y servicios médicos de emergencia para evaluaciones de COVID en el punto de atención. pruebas, y para el tratamiento posterior y decisiones de cuarentena. Rápidamente se creó un equipo multidisciplinario, en cooperación con diferentes instituciones, entre ellas: la Universidad Autónoma de Baja California, la Secretaría de Salud, el Centro de Comando, Comunicaciones y Control Informático. de la Secretaría del Estado de Baja California (C4), Facultades de Medicina y Colegio de Psicólogos. Nuestro objetivo es proporcionar información al público y evaluar COVID-19 en tiempo real y rastrear datos regionales, municipales y estatales en tiempo real que informan las cadenas de suministro y la asignación de recursos con la anticipación de un aumento de COVID-19. 19 casos.ICICT 2023: 2023 The 6th International Conference on Information and Computer Technologieshttps://doi.org/10.1007/978-981-99-3236-

Third International Symposium on Space Mission Operations and Ground Data Systems, part 1

Under the theme of 'Opportunities in Ground Data Systems for High Efficiency Operations of Space Missions,' the SpaceOps '94 symposium included presentations of more than 150 technical papers spanning five topic areas: Mission Management, Operations, Data Management, System Development, and Systems Engineering. The papers focus on improvements in the efficiency, effectiveness, productivity, and quality of data acquisition, ground systems, and mission operations. New technology, techniques, methods, and human systems are discussed. Accomplishments are also reported in the application of information systems to improve data retrieval, reporting, and archiving; the management of human factors; the use of telescience and teleoperations; and the design and implementation of logistics support for mission operations

Lower bound techniques for data structures

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 135-143).We describe new techniques for proving lower bounds on data-structure problems, with the following broad consequences: * the first [omega](lg n) lower bound for any dynamic problem, improving on a bound that had been standing since 1989; * for static data structures, the first separation between linear and polynomial space. Specifically, for some problems that have constant query time when polynomial space is allowed, we can show [omega](lg n/ lg lg n) bounds when the space is O(n - polylog n). Using these techniques, we analyze a variety of central data-structure problems, and obtain improved lower bounds for the following: * the partial-sums problem (a fundamental application of augmented binary search trees); * the predecessor problem (which is equivalent to IP lookup in Internet routers); * dynamic trees and dynamic connectivity; * orthogonal range stabbing. * orthogonal range counting, and orthogonal range reporting; * the partial match problem (searching with wild-cards); * (1 + [epsilon])-approximate near neighbor on the hypercube; * approximate nearest neighbor in the l[infinity] metric. Our new techniques lead to surprisingly non-technical proofs. For several problems, we obtain simpler proofs for bounds that were already known.by Mihai Pǎtraşcu.Ph.D