A wireless multicast network with a stringent decoding delay constraint and a minimum coverage requirement is characterized when the fading channel state information is available only at the receiver side. In the first part, the optimal expected rate achievable by a random user in the network is derived in a single antenna system in terms of the minimum multicast requirement in two scenarios: hard coverage constraint and soft coverage constraint. In the first case, the minimum multicast requirement is expressed by multicast outage capacity while in the second case, the expected multicast rate should satisfy the minimum requirements. Also, the optimum power allocation in an infinite layer superposition code, achieving the highest expected typical rate, is derived. For the MISO case, a suboptimal coding scheme is proposed, which is shown to be asymptotically optimal, when the number of transmit antennas grows at least logarithmically with the number of users in the network. In the second part, a joint source-channel coding scheme is motivated, where a multi-resolution Gaussian source code is mapped to a multi-level channel code. In this part, the hard and soft coverage constraints are defined as maximum outage multicast distortion and maximum expected multicast distortion, respectively. In each scenario, the minimum expected distortion of a typical user is derived in terms of the corresponding coverage constraint. The minimization is first performed for the finite state fading channels and then is extended to the continuous fading channels.

Deployment of mobile nodes in a region of interest is a critical issue in building a mobile sensor network because it affects cost and detection capabilities of the system. The deployment of mobile sensors in essence is the movement of sensors from an initial position to a final optimal location. Considerable attention has recently been given to this deployment issue. Many of the distributed deployment schemes use the potential field method. In most cases, the negative gradient of the potential function becomes the feedback control input to a node. This assumes that the potential function is differentiable over the entire region. This assumption is valid primarily when the topology of the network is fixed. In this research, we analyze the stability of a network that uses piecewise smooth potential functions. A gravitation-like force is proposed to deploy a group of agents and to form a certain configuration. We use a nonsmooth version of the Lyapunov stability theory and LaSalle’s invariance principle to show asymptotic stability of the network which is governed by discontinuous dynamics. We propose a hierarchical structure using potential fields for mobile sensor network deployment. A group of mobile nodes first form a cluster using a potential field method and then cluster heads are used to establish a hexagonal structure that employs a higher level potential field. We consider specifically the problem of deploying a mobile sensor network so that a certain area coverage is realized and maintained. And we propose an algorithm for main taining the desired coverage that assumes the availability of a stochastic sensor model. The model reflects the decline of the sensor accuracy as the distance increases from the sensor. It is further assumed that each node’s sensor has a different sensing range to represent sensor performance deterioration due to power decay. The network deployment scheme combines artificial forces with individual sensor ranges. The validity and the effectiveness of the proposed algorithm are compared to the conventional methods in simulations. Simulation results confirm the effectiveness of the proposed algorithms with respect to a defined performance metric.

Wireless sensor network consists of a large number of sensors, which are capable of sensing, communication and data processing. In wireless sensor network, predictable or unpredictable death of sensor nodes may cause coverage and connectivity problems of the original network. In order to compensate the loss of coverage and connectivity, we propose a region-based movement scheme that divides the neighboring sensors of the dead sensor into a number of regions. The neighboring sensors are moved to repair the regions respectively by using the least mobility distance, and their existing coverage and connectivity are not jeopardized. Our work has better performance of maintaining coverage and connectivity of the network. By the results, our work can decrease the average mobility distance and coverage deterioration substantially.

Concurrency errors are notoriously difficult to debug because they may occur only under unexpected thread interleavings that are difficult to identify and reproduce. These errors are increasingly important as recent hardware trends compel developers to write more concurrent software and to provide more concurrent abstractions. This thesis presents algorithms that dynamically and systematically explore a program's thread interleavings to manifest concurrency bugs quickly and reproducibly, and to provide precise incremental coverage guarantees. Dynamic concurrency testing tools should provide (1) fast response -- bugs should manifest quickly if they exist, (2) reproducibility -- bugs should be easy to reproduce and (3) coverage -- precise correctness guarantees when no bugs manifest. In practice, most tools provide either fast response or coverage, but not both. These goals conflict because a program's thread interleavings exhibit exponential state- space explosion, which inhibits fast response. Two approaches from prior work alleviate state-space explosion. (1) Partial-order reduction provides full coverage by exploring only one interleaving of independent transitions. (2) Bounded search provides bounded coverage by enumerating only interleavings that do not exceed a bound. Bounded search can additionally provide guarantees for cyclic state spaces for which dynamic partial-order reduction provides no guarantees. Without partial-order reduction, however, bounded search wastes most of its time exploring executions that reorder only independent transitions. Fast response with coverage guarantees requires both approaches, but prior work failed to combine them soundly. We combine bounded search with partial-order reduction and extensively analyze the space of dynamic, bounded partial-order reduction strategies. First, we prioritize with a best-first search and show that heuristics that combine these approaches find bugs quickly. Second, we restrict partial-order reduction to combine approaches while maintaining bounded coverage. We specialize this approach for several bound functions, prove that these algorithms guarantee bounded coverage, and leverage dynamic information to further reduce the state space. Finally, we bound the partial order on a program's transitions, rather than the total order on those transitions, to combine these approaches without sacrificing partial-order reduction. This algorithm provides fast response, incremental coverage guarantees, and reproducibility. We manifest bugs an order of magnitude more quickly than previous approaches and guarantee incremental coverage in minutes or hours rather than weeks, helping developers find and reproduce concurrency errors. This thesis makes bounded stateless model checking for concurrent programs substantially more efficient and practical. / text

Nežinomo ploto dengimas yra aktuali ir paplitusi problema. NPD sprendimas realiuose robotuose susiduria su daviklių ir mechanizmų netikslumu. Atliktame darbe yra pateiktas „Bouncing“ NPD algoritmo sprendimas robotui, turinčiam mažo tikslumo daviklius ir neprecizinius valdiklius. Taip pat atliktas darbas parodė sudėtingus roboto kūrimo aspektus ir galimus sprendimus. Sukurtas robotas dėl pigumo ir nesudėtingos realizacijos gali būti naudojamas kaip platforma kitokių algoritmų tyrimui. / The problem of unknown area coverage with mobile robots has received considerable attention over the past years. This problem is a common challenge in many applications, including automatic lawn mowing and vacuum cleaning. However, most of the approaches find difficult to implement in real life because of problems of environment data reading. In this paper we consider the problem of robust area covering algorithm implementation in mobile robot. The chosen approach is based on simple and robust algorithm for uncertain environment and simple robot platform. The results showed robustness, reliability of chosen method of control. The constructed robot has shown simplicity, cheapness of creation and possibility for different algorithm testing. The significance of this paper lies in the practical solution for robust mobile robot area coverage, suitable for noisy environment and low precisions robot sensors.

As a public medium and a vehicle of "culture", which frames and comprehends social priorities, relations and identities, news has received scant anthropological attention (Spitulnik 1993). Whanganui Iwi�s occupation of Moutoa Gardens in 1995 was made available to a public as "news". My project reveals a range of exclusions around these mediations, which conjure wider issues regarding the production of representations within (post) colonial contexts. As a contribution to anthropology, my ethnography responds to the limitations of traditional ethnographic praxis, providing a productive response to criticisms of the discipline and revealing the public value of ethnographic sensibilities. Whanganui Iwi believed the Gardens to be the historical site of Pakaitore pa. The area was reclaimed as a marae, shelters were built, the perimeter fenced, and Iwi lived on site for 80 days. The initiative constituted an expression of Iwi�s experiences of exteriority within Wanganui and their frustration with the delay of the Crown�s response to their claims alleging breaches of Treaty of Waitangi. Iwi temporarily inverted their relationship to the Pakeha community by establishing a literal boundary to the marae, which rendered those who were not supportive of Iwi aspirations "outsiders". While access to the marae was controlled, and restrictions were placed on news workers, the only group banned from the marae were the employees of the city�s newspaper, the Wanganui Chronicle. My project details the production of news about Pakaitore, and the attempts of Iwi to control their representation; specifying the role of "location" (both spatial and ideological) in the production of written and photographic accounts (Haraway 1991). I examine how the structures of news production are deployed and contested by news workers, and the manner in which news texts may or may not be "inhabited" by their subjects and public. I compare the journalistic practices of Chronicle workers, prior to and following their ban, with those of out of town newsworkers from press and television. The mechanisms, codes, and values of what makes "good" news structure particular locations for news workers, and this largely precluded conveying the intention and experience of nga Iwi at Pakaitore. This extended to the reports gathered by the reporter for TVNZ (the state owned broadcaster), who, as Iwi whānau, was allowed unfettered access to the marae. Being "the news" interfered with agendas inside the marae. From this location, Pakaitore was about building relationships between hapu and strengthening a sense of community. Hui addressed the status of Iwi within Wanganui, and rangatahi and visitors were educated in tribal history and tikanga. These priorities contest the "outside" perspective that Pakaitore was simply an attempt to antagonise Pakeha authorities. Throughout the course of my fieldwork visual aspects of media representations of Pakaitore were cited by a range of my informants as conveying particular authority. In some contexts this was by way of revealing the "truth" about the threat of protest to social cohesion, while in others it provided evidence for the media�s inability to represent the initiative in a manner that was sympathetic to, or representative of, Iwi whanau. I argue that the privileging of the disembodied visual reproduces myths of "otherness", covering over experiences of embodied "difference" and the history which renders activism intelligible. My project reveals that in Aotearoa/New Zealand, those contesting the Pakeha imaginary of a "post-racist" culture are cast as producing racial disharmony.

Next generation high performance systems are being standardised assuming a generic service delivery paradigm capable of supporting a diversity of circuit and importantly packet services. However, this flexibility comes at a cost which is the increased complexity of the dimensioning, planning, optimisation and QoS provisioning with respect to previous generation single-service mobile systems. Accurate system dimensioning is of fundamental importance and this thesis explores this requirement at two levels. Firstly, it departs from the common assumption of static users and examines what is the impact of mobile users on the system capacity. Secondly, it examines the impact of voice and web browsing services on the system dimensioning. In spite of the accuracy of dimensioning and planning, load imbalances occur for different reasons, which result in small-scale congestion events in the system. A load equalisation scheme is proposed which utilises the overlapping areas between neighbouring cells in order to eliminate the load imbalances. Essentially, coverage overlapping is needed in order to achieve ubiquitous coverage, hence to eliminate coverage holes. However, excessive overlapping results in capacity loss in interference-limited systems which is virtually the case with all modern systems. Radio coverage optimisation is needed but today this is performed on a cell-by- cell basis producing sub-optimal results. This thesis proposes an advanced coverage optimisation algorithm which takes into consideration simultaneously all cells within the considered area. For the operators (and also the proposed coverage optimisation algorithm) it is Imperative to have accurate path loss predictions. However, contemporary planning tools come with certain limitations, and often time-consuming and expensive measurement campaigns are organised. This thesis builds on the assumption that mobile systems will be able to locate the position of mobile terminals and subsequently proposes an automated process for the estimation of the radio coverage of the network. Lastly, the assumption regarding the positioning capabilities of the mobile systems Is further exploited in order to enhance the QoS guarantees to mobile users. Thus, various algorithms are examined which perform handovers towards base stations which maximise the survivability of the handed over calls.

The coverage and energy issues are the fundamental problems which prevent the development of wireless sensor networks. In order to accurately evaluate the monitoring quality (coverage), one needs to model the interactive of sensors, phenomenons and the environment. Furthermore, in collaborative with scheduling algorithm and computer optimization, protocols can improve the overall monitoring quality and prolong the lifetime of network. This thesis is an investigation of coverage problem and its relative applications in the wireless sensor networks. We first discuss the realistic of current boolean sensing model and propose an irregular sensing model used to determine the coverage in the area with obstacles. We then investigate a joint problem of maintaining the monitoring quality and extending the lifetime of network by using scheduling schemes. Since the scheduling problem is NP hard, genetic algorithm and Markov decision process are used to determine an achievable optimal result for the joint problem of coverage-preserving and lifetime-prolong. In order to avoid the cost of centralized or distributed scheduling algorithms, a localized coverage-preserving scheduling algorithm is proposed by exploring the construction process of Voronoi diagram. Besides exploring the coverage characteristic in a static wireless sensor network, we investigate the coverage problem when the mobile elements are introduced into network. We consider the single-hop mobile data gathering problem with the energy efficiency and data freshness concerns in a wireless sensor network where the connectivity cannot be maintained. We first investigate the upper/lower bound of the covering time for a single collector to cover the monitoring area. Through our investigation we show that for a bounded rectangle area a hexagon walk could explore the area more efficiently than a random walk when the edges of area are known. We then propose a virtual force mobile model (VFM) in which the energy consumption for data transmission is modeled as a virtual elastic force and used to guide of mobile collectors to move to optimal positions for energy saving.

abstract: This work describes an approach for distance computation between agents in a multi-agent swarm. Unlike other approaches, this work relies solely on signal Angleof- Arrival (AoA) data and local trajectory data. Each agent in the swarm is able to discretely determine distance and bearing to every other neighbor agent in the swarm. From this information, I propose a lightweight method for sensor coverage of an unknown area based on the work of Sameera Poduri. I also show that this technique performs well with limited calibration distances. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2020

Test coverage is an important parameter of analyzing how well the product is being tested in any domain within the IT industry. Unit testing is one of the important processes that have gained even more popularity with the rise in Test driven development (TDD) culture.This degree project, conducted at NASDAQ Technology AB, analyzes the existing unit tests in one of the products, and compares various coverage models in terms of quality. Further, the study examines the factors that affect code coverage, presents the best practices for unit testing, and a proven test process used in a real world project.To conclude, recommendations are given to NASDAQ based on the findings of this study and industry standards. / Testtäckning är en viktig parameter för att analysera hur väl en produkt är testad inom alla domäner i IT-industrin. Enhetstestning är en av de viktiga processerna som har ökat sin popularitet med testdriven utveckling. Detta examensarbete, utfört på NASDAQ Technology AB, analyserar de befintliga testen i en av produkterna, och jämför olika kvalitetsmodeller. Vidare undersöker undersökningen de faktorer som påverkar koddekning, presenterar de bästa metoderna för enhetstestning och en beprövad testprocess som används i ett verkligt världsprojekt. Avslutningsvis ges rekommendationer till NASDAQ baserat på resultaten från denna studie och industristandarder.