Дисертації з теми "Mobius search"

This thesis project is about the search and secure problem for mobile robots. The search and secure problem refers to the problem where possible moving intruders have to be detected in a given area with obstacles that are represented as polygons. The solution to this problem is given by deploying robots in a proper way so that no intruder can remain undetected or sneak back to a secured area. An intruder is considered detected when he/she is in the field of view of the robots’ on-board cameras. As a first step, in the algorithm that solves the search and secure problem, the area is divided into triangles. The resulting triangles are then merged in order to form convex polygons. The next step is to abstract the actual regions into a topological graph where each polygon is represented by its centroid and the neighboring polygons are connected by edges. At this point, blocking robots are used to break the loops in the graph and prevent the intruders from escaping from the searchers. Then the number of the searchers is determined and their paths are created. Two solutions are proposed, one that requires more searchers but less time and one that requires the minimum number of searchers but more time. The last step is to create the trajectories that the robots have to follow. The functionality and the efficiency of the algorithm is verified through simulations and the results are visualized using Matlab and the AURES simulator and controller. The demonstration that was held at SAAB facilities in Linköping is also described.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2007.
Thesis Advisor(s): Singh, Gurminder ; Otani, Thomas. "September 2007." Description based on title screen as viewed on October 22, 2007. Includes bibliographical references (p. 83-87). Also available in print.

Despite the tremendous popularity of mobile applications, mobile testing still relies heavily on manual testing. This thesis presents mobile test automation approaches based on multi-objective search. We introduce three approaches: Sapienz (for native Android app testing), Octopuz (for hybrid/web JavaScript app testing) and Polariz (for using crowdsourcing to support search-based mobile testing). These three approaches represent the primary scientific and technical contributions of the thesis. Since crowdsourcing is, itself, an emerging research area, and less well understood than search-based software engineering, the thesis also provides the first comprehensive survey on the use of crowdsourcing in software testing (in particular) and in software engineering (more generally). This survey represents a secondary contribution. Sapienz is an approach to Android testing that uses multi-objective search-based testing to automatically explore and optimise test sequences, minimising their length, while simultaneously maximising their coverage and fault revelation. The results of empirical studies demonstrate that Sapienz significantly outperforms both the state-of-the-art technique Dynodroid and the widely-used tool, Android Monkey, on all three objectives. When applied to the top 1,000 Google Play apps, Sapienz found 558 unique, previously unknown crashes. Octopuz reuses the Sapienz multi-objective search approach for automated JavaScript testing, aiming to investigate whether it replicates the Sapienz’ success on JavaScript testing. Experimental results on 10 real-world JavaScript apps provide evidence that Octopuz significantly outperforms the state of the art (and current state of practice) in automated JavaScript testing. Polariz is an approach that combines human (crowd) intelligence with machine (computational search) intelligence for mobile testing. It uses a platform that enables crowdsourced mobile testing from any source of app, via any terminal client, and by any crowd of workers. It generates replicable test scripts based on manual test traces produced by the crowd workforce, and automatically extracts from these test traces, motif events that can be used to improve search-based mobile testing approaches such as Sapienz.

Purpose: The purpose of this study is to understand millennials search behavior on mobile devices. Research Questions: How do millennials value organic and sponsored search results on mobile devices? What are the Web advertising variables that affect millennials attitudes towards sponsored search ads on mobile devices? Methodology: Data was collected from 103 Swedish millennials through an experiment and survey. Conclusion: The findings of this research supports the variables of entertainment and incentives to have a positive association with millennials attitudes towards mobile search ads while irritation, informativeness and credibility were only partially supported when testing independently with attitudes. An overall negative attitude could be seen toward sponsored links when participants motivated their action to click. Moreover, the results illustrated a higher attitude value towards mobile search ads to reflect an increased click behavior on sponsored search results.

This thesis discusses the possibilities to visualise the presentation layer of a search engine on a mobile device in an alternative way. Previous work in the area has shown that the use of text-based-lists can be problematic when accessed on a device with a limited display. In the scope of the thesis and in order to tackle the current problems when displaying the results a literature review was carried out. The findings of the review formed the basis for a requirement definition on which a mock-up was developed. The mock-up was then evaluated and tested during a usability test where a number of users got to experience the alternative presentation layer that uses a visualisation technique called tree- map. The results from the test show that the mock-up could be seen as a alternative to the current presentation of results. The mock-up also shows that a future implementation could also include the use of categories and sorting of information in order to provide content with a meaning.

Mobile manipulators are a potential solution to the increasing need for additional flexibility and mobility in industrial robotics applications. However, they tend to lack the accuracy and precision achieved by fixed manipulators, especially in scenarios where both the manipulator and the autonomous vehicle move simultaneously. This thesis analyzes the problem of dynamically evaluating the positioning error of mobile manipulators. In particular, it investigates the use of Bayesian methods to predict the position of the end-effector in the presence of uncertainty propagated from the mobile platform. Simulations and real-world experiments are carried out to test the proposed method against a deterministic approach. These experiments are carried out on two mobile manipulators—a proof-of-concept research platform and an industrial mobile manipulator—using ROS and Gazebo. The precision of the mobile manipulator is evaluated through its ability to intercept retroreflective markers using a photoelectric sensor attached to the end-effector. Compared to the deterministic search approach, we observed improved interception capability with comparable search times, thereby enabling the effective performance measurement of the mobile manipulator.

In this thesis, we study object ranking in mobile 3D visual search. The conventional methods of object ranking achieve ranking results based on the appearance of objects in images captured by mobile devices while ignoring the underlying 3D geometric information. Thus, we propose to use the method of mobile 3D visual search to improve the ranking by using the underlying 3D geometry of the objects. We develop an algorithm of fast 3D geometric verication to re-rank the objects at low computational complexity. In that scene, the geometry of the objects such as round corners, sharp edges, or planar surfaces as well as the appearance of objects will be considered for 3D object ranking. On the other hand, we also investigate flaws of conventional vocabulary trees and improve the ranking results by introducing a credibility value to the TF-IDF scheme. By combining novel vocabulary trees and fast 3D geometric verification, we can improve the recall-datarate performance as well as the subjective ranking results for mobile 3D visual search.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 123-131).
Cameras of good quality are now available on handheld and wearable mobile devices. The high resolution of these cameras coupled with pervasive wireless connectivity and advanced computer vision algorithms makes it feasible to develop new ways to interact with mobile video. Two important examples are interactive object recognition and search-by-content. Interactive recognition continuously locates objects in a video stream, recognizes them, and labels them with information associated with the objects in the user's view. Example use cases include an augmented shopping application that recognizes products or brands to inform customers about the items they buy and a driver assistance application that recognizes vehicles and signs to improve driver safety. Interactive search-by-content allows users to discover videos using textual queries (e.g., "child dog play"). Instead of requiring broadcasters to manually annotate videos with meta-data tags, our search system uses vision algorithms to automatically produce textual tags. These two services must be highly interactive because users expect timely feedback for their interactions and changes in content. However, achieving high interactivity without sacrificing accuracy or efficiency is challenging. The required computer vision algorithms use computationally intensive deep neural networks and must run at a frame rate of 30 frames per second. Recognizing an object scales with the size of the corpus of objects, and is infeasible on a mobile device. Off-loading recognition operations to servers introduces network and processing delay; when this delay is higher than a frame-time, it degrades recognition accuracy. This dissertation presents two systems that study the trade-off between accuracy and efficiency for interactive recognition and search, and demonstrate how to achieve both goals. Glimpse enables interactive object recognition for camera-equipped mobile devices. Because the algorithms for object recognition entail significant computation, Glimpse runs them on servers across the network. To "hide" latency, Glimpse uses an active cache of video frames on the device and performs tracking on a subset of frames to correct the stale results obtained from the processing pipeline. Our results show that Glimpse achieves a precision of 90% for face recognition, which improves over a scheme performing server-side recognition without using an active cache by 2.8 x. For fast moving objects such as road signs, Glimpse achieves precision up to 80%; without using the active cache, interactive recognition is non-functional (1.9% precision). Panorama enables search on live video streams. It introduces three new mechanisms: (1) an intelligent frame selector that reduces the number of frames on which expensive recognition must be run, (2) a distributed scheduler that uses feedback from the vision algorithms to dynamically determine the order in which streams must be processed, and (3) a search-ranking method that uses visual features to improve search relevance. Our experimental results show that incorporating visual features doubles search relevance from 45% to 90%. To achieve 90% search accuracy, with current pricing from Amazon Web Services, Panorama incurs 24x lower cost than a scheme that recognizes every frame.
by Yu-Han Tiffany Chen.
Ph. D.

The remarkable spread of the Internet has generated new opportunities for companies to promote themselves and communicate with their customers. The most used Internet service of finding information today is search engines (e.g. Google, Bing, Yahoo) were almost three million searches are preformed every minute worldwide. This trend has led to an importance for companies having their websites visible on these search engines. In addition, people tend to be more and more on the go and are searching with their smartphones instead of traditional personal computer (PC). Meaning that companies’ websites can be available for customers 24 hour a day, 7 days a week, independent on customers location. Consequently, companies have the possibilities to reach the attention of customers when they actually search for a product/service and are therefore most likely to purchase.   In this thesis a marketing strategy has been developed for managers regarding how to master this new communication tool, in order to reach success and competitive advantage. This strategy was developed by investigate in what characteristics and functions users desire when searching with their smartphone. Together with three hypotheses tested if the perceived user-friendliness, relative advantage and compatibility within mobile search have a positive affect on the intention of use this new technology.   In this bachelor thesis a survey was conducted among people in generation C living in Sweden, which resulted in 397 completed responses. The hypotheses were tested with use of a regression analysis and the findings were that the relative advantage and compatibility in mobile search has a positive affect on the intention of use. Therefore, this thesis suggests companies to develop their mobile search engine marketing strategy with the aim of delivering value and satisfying the customer. Moreover, this thesis recommend managers to keep their mobile website quick, relevant and making sure having valuable and informative information about their business in the description text visible to users in the search engine hit list.   Finally, the majority of the population does already act on this new market and it is therefore of great importance for companies satisfying these users in order to stay competitive.

The thesis work intends to provide architecture for mobile local information search service using Wireless LAN and cellular integration. Search technology has been popular and driving business bodies with increasing e-commerce opportunities. The search technology has been recently brought to portable devices such as mobile phones and PDA devices by extending the research scope. Mobile search revenues are expected to surpass Internet search revenues in near future. Mobile local search on the other hand is getting much popular with growing number of mobile subscribers. Mobile phones have been chosen to provide mobile local search services because of its high possessivity and portable nature. In this thesis work, the author would like to propose a generalized architecture for mobile local information search in a new perspective by involving cellular service provider directly with a minimum co-operation from consumers and retailers. When providing mobile local search services, cellular operator has to maintain a replica of databases of all the existing retailers. Updating the replica at cellular operator at regular intervals has been leading to synchronization problems that produce out-dated results to mobile users. The aspects that have driven the author towards proposing the architecture are solving database synchronization problems and thriving for effective search results. The existing architecture of web search, mobile search and mobile local search are analyzed to identify the domain specific challenges and research gaps. Proposed architecture is designed and evaluated by using an approach called Architecture Tradeoff Analysis Method (ATAM). The architecture is evaluated against its quality attributes and the results are presented.
Sridher Rao Sidduri Lindblomsvagen, 97, Rum no 555, 372 33 Ronneby, Sweden E-mail: srsi05@student.bth.se

Mobile Visual Search (MVS) is a research field which focuses on the recognition of real-world objects by using mobile devices such as smart phones or robots. Current mobile visual search solutions achieve search results based on the appearance of the objects in images captured by mobile devices. It is suitable for planar structured objects such as CD cover images, magazines and art works. However, these solutions fail if different real objects appear similar in the captured images. To solve this problem, the novel solution captures not only the visual appearance of the query object, but uses also the underlying 3D geometry. Vocabulary Tree (VT) methods have been widely used to efficiently find the match for a query in the database with a large volume of data. In this thesis, we study the vocabulary tree in the scenario of multi-view imagery for mobile visual search. We use hierarchically structured multi-view features to construct a multi-view vocabulary trees which represent the 3D geometric information of the objects. Relevant aspects of vocabulary trees such as the shaping of trees, tf-idf weighting and scoring functions have been studied and incorporated in the multi-view scenario. The experimental results show that our multi-view vocabulary trees improve the matching and ranking performance of mobile visual search.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 181-187) and index.
This dissertation considers a suite of search problems in which agents are trying to find goals in minimum expected time. Unlike search in data structures in which time is measured by a number operations, search in metric spaces measures time by units of distance and has received much less attention. In particular, search strategies that attempt to minimize expected search time are only available for a handful of relatively simple cases. Nonetheless many relevant search problems take place in metric spaces. This dissertation includes several concrete examples from navigation and surveillance that would have previously only been approachable by much more ad hoc methods. We visit these examples along the way to establishing relevance to a much larger set of problems. We present a policy that is an extension of Whittle's index heuristic and is applicable under the following assumptions. * The location of goals are independent random variables. " The agents and goals are in a length space, i.e., a metric space with continuous paths. * The agents move along continuous paths with bounded speed. " The agents' sensing is noiseless. We demonstrate the performance of our policy by applying it to a diverse set of problems for which solutions are available in the literature. We treat each of the following problems as a special case of a more general search problem: " search in one-dimensional spaces such as the Line Search Problem (LSP) and Cow Path Problem (CPP), " search in two-dimensional spaces such as the Lost in a Forest Problem (LFP) and problems of coverage, " problems in networks such as the Graph Search Problem (GSP) and Minimum Latency Tour Problem (MLTP), and " dynamic problems such as the Persistent Patrol Problem (PPP) and Dynamic Traveling Repairperson Problem (DTRP). On each of these we find that our policy performs comparably to, and occasionally better than, the accepted solutions developed specifically for these problems. As a result, we believe that this dissertation contributes a significant inroad into a large space of search problems that meets our assumptions, but that remains unaddressed.
by Thomas. J. Temple.
Ph.D.

Search interfaces have for a long time been targeted at the resource-rich languages, such as English. There has been little effort to support African (Bantu) languages in search interfaces when compared to languages such as English, particularly the isiXhosa language. However, due to the increase in use of mobile phones in developing countries, these interfaces can now be adapted to languages in these settings to support information access on the Web. This study proposes mobile search interfaces to support isiXhosa speakers to search for information on the Web using isiXhosa as a discovery language. The isiXhosa language is considered a low-resourced African (Bantu) language spoken in resource-constrained environments in South Africa. The language is spoken by over eight million people. Yet, there has been no search interface specifically targeted at supporting isiXhosa speakers. Two mobile search interfaces were developed on an Android application. The interfaces were text based and voice based. The design of the interfaces was based on feedback from 4 native isiXhosa speakers in a design focus group, and guidelines from the literature. Using the developed interfaces, an experiment was conducted with 34 native isiXhosa speaking students at the University of Cape Town, South Africa. This was done to investigate, which interface could better support isiXhosa speakers to search for information on the Web using mobile phones. Quantitative data was collected using application log files. Additionally, user feedback was then obtained using the standard Software Usability Measurement Inventory (SUMI) instrument, and both interfaces were confirmed as usable. In contrast to what was expected, users preferred the text interface in general, and according to most SUMI subscales. This could be because of greater familiarity with text search interfaces or because of the relative scarcity of voice interfaces in African (Bantu) languages. Where users are not literate, the voice interface may be the only option, so the fact that it was deemed usable is an important independent finding. Search in African (Bantu) language collections is still a largely unexplored field, and more work needs to be done on the interfaces as the algorithms and collections are developed in parallel.

Many recent applications using local image features focus on 2D image recognition. Such applications can not distinguish between real objects and photos of objects. In this project, we present a 3D object recognition method using stereo images. Using the 3D information of the objects obtained from stereo images, objects with similar image description but different 3D shapes can be distinguished, such as real objects and photos of objects. Besides, the feature matching performance is improved compared with the method using only local image features. Knowing the fact that local image features may consume higher bitrates than transmitting the compressed images itself, we evaluate the performance of a recently proposed low-bitrate local image feature descriptor CHoG in 3D object reconstruction and recognition, and propose a difference compression method based on the quantized CHoG descriptor, which further reduces bitrates.

Urban Search and Rescue is a dangerous task for rescue workers and for this reason the use of mobile robots to carry out the search of the environment is becoming common place. These robots are remotely operated and the search is carried out by the robot operator. This work proposes that common search algorithms can be used to guide a single autonomous mobile robot in a search of an environment and locate survivors within the environment. This work then goes on to propose that multiple robots, guided by the same search algorithms, will carry out this task in a quicker time. The work presented is split into three distinct parts. The first is the development of a nonlinear mathematical model for a mobile robot. The model developed is validated against a physical system. A suitable navigation and control system is required to direct the robot to a target point within an environment. This is the second part of this work. The final part of this work presents the search algorithms used. The search algorithms generate the target points which allow the robot to search the environment. These algorithms are based on traditional and modern search algorithms that will enable a single mobile robot to search an area autonomously. The best performing algorithms from the single robot case are then adapted to a multi robot case. The mathematical model presented in the thesis describes the dynamics and kinematics of a four wheeled mobile ground based robot. The model is developed to allow the design and testing of control algorithms offline. With the model and accompanying simulation the search algorithms can be quickly and repeatedly tested without practical installation. The mathematical model is used as the basis of design for the manoeuvring control algorithm and the search algorithms. This design process is based on simulation studies. In the first instance the control methods investigated are Proportional-Integral-Derivative, Pole Placement and Sliding Mode. Each method is compared using the tracking error, the steady state error, the rise time, the charge drawn from the battery and the ability to control the robot through a simple motion. Obstacle avoidance is also covered as part of the manoeuvring control algorithm. The final aspect investigated is the search algorithms. The following search algorithms are investigated, Lawnmower, Random, HillClimbing, Simulated Annealing and Genetic Algorithms. Variations on these algorithms are also investigated. The variations are based on Tabu Search. Each of the algorithms is investigated in a single robot case with the best performing investigated within a multi robot case. A comparison between the different methods is made based on the percentage of the area covered within the time available, the number of targets located and the time taken to locate targets. It is shown that in the single robot case the best performing algorithms have high random elements and some structure to selecting points. Within the multi robot case it is shown that some algorithms work well and others do not. It is also shown that the useable number of robots is dependent on the size of the environment. This thesis concludes with a discussion on the best control and search algorithms, as indicated by the results, for guiding single and multiple autonomous mobile robots. The advantages of the methods are presented, as are the issues with using the methods stated. Suggestions for further work are also presented.

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2015-2016
Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2015-2016
Nous abordons deux problèmes différents et complémentaires : le problème du chemin couvrant (ou CPP) et le problème du chemin de recherche optimal (ou OSP). Le CPP est un défi important en robotique mobile alors que l’OSP est un classique de la théorie de la recherche. Nous effectuons d’abord une revue de littérature qui souligne leurs différences et leurs similitudes du point de vue d’une opération de recherche. Le CPP et l’OSP sont comparés par rapport aux données connues sur la position d’un objet de recherche. Ensuite, nous formalisons une généralisation du problème CPP aux détections imparfaites et distantes nommée CPPIED. Nous présentons un algorithme heuristique efficace qui utilise à la fois la programmation dynamique et une réduction au problème du voyageur de commerce (TSP). Nous appliquons l’algorithme dans le contexte des opérations de déminage sous-marin sur des cartes qui contiennent plus de 21 000 cellules. Nous poursuivons par l’étude d’un nouveau modèle de programmation par contraintes (CP) pour l’OSP pour lequel nous proposons une amélioration de la définition de la fonction objectif. Cette nouvelle définition permet un filtrage plus fort des variables de probabilité prodiguant ainsi une amélioration des performances du modèle. Nous proposons, pour l’OSP, une nouvelle heuristique nommée « détection totale » (ou TD). Les résultats expérimentaux démontrent que notre modèle, utilisé avec l’heuristique TD, est compétitif avec des algorithmes de séparation et d’évaluation (ou branch-and-bound) spécifiques au problème de l’OSP (l’approche CP étant plus générale). Cette dernière observation supporte notre assertion que la CP est un bon outil pour résoudre des problèmes de la théorie de la recherche. Finalement, nous proposons la contrainte de transition de Markov (Mtc) en tant que nouvel outil de modélisation pour simplifier l’implémentation de modèles basés sur les chaînes de Markov. Nous démontrons, tant empiriquement que formellement, que l’arithmétique des intervalles est insuffisante pour l’atteinte de la cohérence de bornes, c’est-à-dire, pour filtrer les variables de probabilité de cette contrainte. Or, l’arithmétique des intervalles est l’outil utilisé par les solveurs CP pour filtrer une Mtc lorsque celle-ci est décomposée en contraintes arithmétiques individuelles. Nous proposons donc un algorithme basé sur la programmation linéaire qui atteint la cohérence de bornes. Du fait que la programmation linéaire est coûteuse en temps de calcul pour un solveur CP lorsqu’utilisée à chaque noeud de l’arbre de recherche, nous proposons aussi une approche intermédiaire basée sur le problème du sac à dos fractionnel. L’utilisation des Mtcs est illustrée sur l’OSP.
Nous abordons deux problèmes différents et complémentaires : le problème du chemin couvrant (ou CPP) et le problème du chemin de recherche optimal (ou OSP). Le CPP est un défi important en robotique mobile alors que l’OSP est un classique de la théorie de la recherche. Nous effectuons d’abord une revue de littérature qui souligne leurs différences et leurs similitudes du point de vue d’une opération de recherche. Le CPP et l’OSP sont comparés par rapport aux données connues sur la position d’un objet de recherche. Ensuite, nous formalisons une généralisation du problème CPP aux détections imparfaites et distantes nommée CPPIED. Nous présentons un algorithme heuristique efficace qui utilise à la fois la programmation dynamique et une réduction au problème du voyageur de commerce (TSP). Nous appliquons l’algorithme dans le contexte des opérations de déminage sous-marin sur des cartes qui contiennent plus de 21 000 cellules. Nous poursuivons par l’étude d’un nouveau modèle de programmation par contraintes (CP) pour l’OSP pour lequel nous proposons une amélioration de la définition de la fonction objectif. Cette nouvelle définition permet un filtrage plus fort des variables de probabilité prodiguant ainsi une amélioration des performances du modèle. Nous proposons, pour l’OSP, une nouvelle heuristique nommée « détection totale » (ou TD). Les résultats expérimentaux démontrent que notre modèle, utilisé avec l’heuristique TD, est compétitif avec des algorithmes de séparation et d’évaluation (ou branch-and-bound) spécifiques au problème de l’OSP (l’approche CP étant plus générale). Cette dernière observation supporte notre assertion que la CP est un bon outil pour résoudre des problèmes de la théorie de la recherche. Finalement, nous proposons la contrainte de transition de Markov (Mtc) en tant que nouvel outil de modélisation pour simplifier l’implémentation de modèles basés sur les chaînes de Markov. Nous démontrons, tant empiriquement que formellement, que l’arithmétique des intervalles est insuffisante pour l’atteinte de la cohérence de bornes, c’est-à-dire, pour filtrer les variables de probabilité de cette contrainte. Or, l’arithmétique des intervalles est l’outil utilisé par les solveurs CP pour filtrer une Mtc lorsque celle-ci est décomposée en contraintes arithmétiques individuelles. Nous proposons donc un algorithme basé sur la programmation linéaire qui atteint la cohérence de bornes. Du fait que la programmation linéaire est coûteuse en temps de calcul pour un solveur CP lorsqu’utilisée à chaque noeud de l’arbre de recherche, nous proposons aussi une approche intermédiaire basée sur le problème du sac à dos fractionnel. L’utilisation des Mtcs est illustrée sur l’OSP.
We tackle two different and complementary problems: the coverage path planning (CPP) and the optimal search path (OSP). The CPP is a main challenge in mobile robotics. The OSP is a classic from search theory. We first present a review of both problems that highlights their differences and their similarities from the point of view of search (coverage) operations. Both problems are positioned on the continuum of the a priori knowledge on the whereabouts of a search object. We then formalize an extension of the CPP we call the CPP with imperfect extended detections (CPPIED). We present a novel and powerful heuristic algorithm that uses dynamic programming and a traveling salesman (TSP) reduction. We apply the method to underwater minesweeping operations on maps with more than 21 thousand cells. We then study a novel constraint programming (CP) model to solve the OSP.We first improve on using the classical objective function found in the OSP definition. Our novel objective function, involving a single modification of the operators used to compute the probability of success of a search plan, leads to a stronger filtering of the probability variables of the model. Then, we propose a novel heuristic for the OSP: the total detection (TD) heuristic. Experiments show that our model, along with the proposed heuristic, is competitive with problem-specific branch-and-bounds supporting the claim that CP is a good technique to solve search theory problems. We finally propose the Markov transition constraint (Mtc) as a novel modeling tool in CP to simplify the implementation of models based on Markov chains. We prove, both empirically and theoretically, that interval arithmetic is insufficient to filter the probability variables of a single Mtc, i.e., to enforce bounds consistency on these variables. Interval arithmetic is the only available tool to filter an Mtc when it is decomposed into individual arithmetic constraints. We thus propose an algorithm based on linear programming which is proved to enforce bounds consistency. Since linear programming is computationally expensive to use at each node of the search tree of a CP solver, we propose an in-between solution based on a fractional knapsack filtering. The Mtc global constraint usage is illustrated on a CP model of the OSP.
We tackle two different and complementary problems: the coverage path planning (CPP) and the optimal search path (OSP). The CPP is a main challenge in mobile robotics. The OSP is a classic from search theory. We first present a review of both problems that highlights their differences and their similarities from the point of view of search (coverage) operations. Both problems are positioned on the continuum of the a priori knowledge on the whereabouts of a search object. We then formalize an extension of the CPP we call the CPP with imperfect extended detections (CPPIED). We present a novel and powerful heuristic algorithm that uses dynamic programming and a traveling salesman (TSP) reduction. We apply the method to underwater minesweeping operations on maps with more than 21 thousand cells. We then study a novel constraint programming (CP) model to solve the OSP.We first improve on using the classical objective function found in the OSP definition. Our novel objective function, involving a single modification of the operators used to compute the probability of success of a search plan, leads to a stronger filtering of the probability variables of the model. Then, we propose a novel heuristic for the OSP: the total detection (TD) heuristic. Experiments show that our model, along with the proposed heuristic, is competitive with problem-specific branch-and-bounds supporting the claim that CP is a good technique to solve search theory problems. We finally propose the Markov transition constraint (Mtc) as a novel modeling tool in CP to simplify the implementation of models based on Markov chains. We prove, both empirically and theoretically, that interval arithmetic is insufficient to filter the probability variables of a single Mtc, i.e., to enforce bounds consistency on these variables. Interval arithmetic is the only available tool to filter an Mtc when it is decomposed into individual arithmetic constraints. We thus propose an algorithm based on linear programming which is proved to enforce bounds consistency. Since linear programming is computationally expensive to use at each node of the search tree of a CP solver, we propose an in-between solution based on a fractional knapsack filtering. The Mtc global constraint usage is illustrated on a CP model of the OSP.

The rapid growth of touchscreen mobile devices has opened up many new opportunities for exploring Content-based Image Retrieval (CBIR) techniques, e.g., it has enabled the development of intuitive and natural user interfaces to facilitate the Query-by-Drawing (QbD) image search paradigm. Although ubiquitous mobile computing holds the promise of drastically changing the ways users search for images from large image repositories, there is yet no comprehensive and systematic study that examines the factors that influence the usability, user behaviours and task performance of a QbD image search mobile application (App). No guidelines and principles exist for designing fundamental user interface components such as the colour picker and little is known how its different designs affect system usability and task performance. Little research exists that examines how different user interface designs affect the ways users draw the queries and how users go about the search process for different types of tasks. The questions of whether or not it is possible or how well users can perform QbD image search by drawing from memory of previously-seen images are unexplored. An understanding of these questions is very important and useful in the development of effective and user-friendly systems for a QbD image search App on touchscreen mobile devices. This PhD project attempts to answer these questions and more by examining the factors that influence the usability and task performance of a QbD painting search mobile application. Starting with a comprehensive literature review and current mobile App review of various related fields, we first designed and implemented a Client-Server painting search mobile App based on an existing CBIR algorithm as the research platform for collecting empirical data; we then conducted a focus group study from whose findings we re-designed the user interfaces of our QbD App. An online survey about art preference was carried out, and we designed four comprehensive user studies and recruited a total of 123 participants to take part in the experiments. Both qualitative and quantitative measures are collected and analysed to discover the various factors that influence the usability and task performance of the interface designs of a QbD image search mobile App and the memory drawing over time. Finally, we made recommendations and suggestions on the design and implementation of various interface components of the QbD image search mobile App based on our findings. This thesis presents the following contributions summarised as: 1) We build a flexible platform that can be used for research in drawing-related fields, such as a new QbD technique or interface tests and psychological study. 2)We present a comprehensive and systematic review of the methods and techniques related to the investigation of QbD image search mobile App. 3) We propose a new way of categorising colour picker: ‘1D-1D-1D’, ‘1D-2D’, and ‘3D’ colour picker. 4) The rationales of choosing stimuli are proposed and a real-world painting database is built. 5) We also develop a variety of novel methodologies for experimental design, data collection and data analysis, and we formulated a new protocol for assessing drawing accuracy and search result. 6) We propose some colour picker design guidelines through a series of experiments and the analysis of comprehensive experimental data. 7) Although indeed memory decays over time, we found the participants are able to draw from the memory of a painting with simple compositional structure (6-7 colour blobs), even for the paintings viewed a month ago. And finally, 8) the experiments also provide valuable insights into how general users draw and modify a query, and judge the result relevance for different tasks on mobile phones, as well as search pattern and memorisation strategy, which also extend a scientific understanding of using current Query-by-Drawing techniques for real world image search.

In this thesis we consider the problem of searching for an intruder in a network. There is a team of collaborative software agents that are deployed to capture a hostile intruder (e.g., a virus). These agents move along the network links and the intruder has the capability of escaping arbitrarily fast. We propose different strategies for the solution of the problem in some widely used topologies for the local area network and interconnection network: hypercube network, butterfly network and chordal ring network. In each topology, different models are studied depending on the capabilities of agents; i.e., agents' synchronicity, cloning power and visibility. For each model, we analyze the strategies in terms of number of agents employed, number of moves performed by the agents, and time.

In urban search and rescue (USAR) operations, there is a considerable amount of danger faced by rescuers. The use of mobile robots can alleviate this issue. Coordinating the search effort is made more difficult by the communication issues typically faced in these environments, such that communication is often restricted. With small numbers of robots, it is necessary to break communication links in order to explore the entire environment. The robots can be viewed as a broken ad hoc network, relying on opportunistic contact in order to share data. In order to minimise overheads when exchanging data, a novel algorithm for data exchange has been created which maintains the propagation speed of flooding while reducing overheads. Since the rescue workers outside of the structure need to know the location of any victims, the task of finding their locations is two parted: 1) to locate the victims (Search Time), and 2) to get this data outside the structure (Delay Time). Communication with the outside is assumed to be performed by a static robot designated as the Command Station. Since it is unlikely that there will be sufficient robots to provide full communications coverage of the area, robots that discover victims are faced with the difficult decision of whether they should continue searching or return with the victim data. We investigate a variety of search techniques and see how the application of biological foraging models can help to streamline the search process, while we have also implemented an opportunistic network to ensure that data are shared whenever robots come within line of sight of each other or the Command Station. We examine this trade-off between performing a search and communicating the results.

The rapid development of mobile technologies has facilitated users to generate and store files on mobile devices. However, it has become a challenging issue for users to search efficiently and effectively for files of interest in a mobile environment that involves a large number of mobile nodes. In this thesis, file management and retrieval alternatives have been investigated to propose a feasible framework that can be employed on resource-limited devices without altering their operating systems. The file annotation and retrieval framework (FARM) proposed in the thesis automatically annotates the files with their basic file attributes by extracting them from the underlying operating system of the device. The framework is implemented in the JME platform as a case study. This framework provides a variety of features for managing the metadata and file search features on the device itself and on other devices in a networked environment. FARM not only automates the file-search process but also provides accurate results as demonstrated by the experimental analysis. In order to facilitate a file search and take advantage of the Semantic Web Technologies, the SemFARM framework is proposed which utilizes the knowledge of a generic ontology. The generic ontology defines the most common keywords that can be used as the metadata of stored files. This provides semantic-based file search capabilities on low-end devices where the search keywords are enriched with additional knowledge extracted from the defined ontology. The existing frameworks annotate image files only, while SemFARM can be used to annotate all types of files. Semantic heterogeneity is a challenging issue and necessitates extensive research to accomplish the aim of a semantic web. For this reason, significant research efforts have been made in recent years by proposing an enormous number of ontology alignment systems to deal with ontology heterogeneities. In the process of aligning different ontologies, it is essential to encompass their semantic, structural or any system-specific measures in mapping decisions to produce more accurate alignments. The proposed solution, in this thesis, for ontology alignment presents a structural matcher, which computes the similarity between the super-classes, sub-classes and properties of two entities from different ontologies that require aligning. The proposed alignment system (OARS) uses Rough Sets to aggregate the results obtained from various matchers in order to deal with uncertainties during the mapping process of entities. The OARS uses a combinational approach by using a string-based and linguistic-based matcher, in addition to structural-matcher for computing the overall similarity between two entities. The performance of the OARS is evaluated in comparison with existing state of the art alignment systems in terms of precision and recall. The performance tests are performed by using benchmark ontologies and the results show significant improvements, specifically in terms of recall on all groups of test ontologies. There is no such existing framework, which can use alignments for file search on mobile devices. The ontology alignment paradigm is integrated in the SemFARM to further enhance the file search features of the framework as it utilises the knowledge of more than one ontology in order to perform a search query. The experimental evaluations show that it performs better in terms of precision and recall where more than one ontology is available when searching for a required file.

Search and rescue (SAR) mission always takes place when disasters happen. Disaster could be defined into two categories, namely natural disaster and man-made disaster. Natural disasters normally cover a large area making the SAR mission’s team require an aerial view from airplane. This is because it changes the geographical landscape of the affected areas in huge perimeters. The impact is not only changing the whole landscapes, but it also impacts on residences, commercial buildings, transportations and communication infrastructures. This is always the primary reason of choosing an air vehicle as a first respond for any natural disaster. Meanwhile, made-made disasters occur in small areas relative to natural disaster. Terrorist bombing, structural collapse because of human failures or serious accident are some examples of man-made disaster. In addition, the effect from natural disaster such as earthquake also resulting horrendous structural collapse. The challenges for this rescue operation are focused on the interior of the rubble and entire external extent of the damage often not as primary interest because most victims are trapped inside, under the rubbles. Locating, extracting and rescuing any survivors will become the main goal for any rescue mission. Besides, the mission also deals with a lot of potentially dangerous situation such as further collapse, explosions, hazardous gas leaks and fire. Extreme high temperature from fire or explosions prevent rescuer to go down further into rubbles. Urban search and rescue (USAR) is the term that is being used recently for the rescue operation after man-made disaster. Conventionally, dog has been used to identify location of any potential survivors in the rubble. Again, capabilities of dog rescuer are restricted by certain working temperature, uncertainty of void size and fatigue factor. USAR operation is like race against time where trapped survivors cannot wait any longer. Further collapse or explosion may happen anytime. Therefore, the rescue team should have ideal strategy and tactic in order to maximize numbers of survivors being extract from rubble but also minimise the risk face by rescuer. Hazards is everywhere at disaster site. Human rescuers as well as dog are exposed to danger such as further collapse which would trap them in rubble and resulting an increased number of victims. This kind of situation make USAR uncertain. As a result, hazard identification and situation awareness have to be conducted concurrently with finding survivors. Robotic system, in many ways, have shown its versatility in wide range of applications. For instance, a modern and sophisticated automative assembly plant employ robotic systems in the production line in order to fullfil a specific part assembly task. On the other hand, robotic systems also started to be used as exploration vehicle in unknown world such as deep sea and outer space exploration purposes. In many aspects, the implementation of robotic systems in these applications have a significant impact to the overall process flow of the specific application. Having said that, mobile robots use in many deep sea explorations help scientists to discover the 'underworld' where human cannot explore. Therefore, implementation of robotic system in USAR operation is inevitable. In fact, it has been used in several USAR operation including the 9/11 World Trade Centre tragedy and Fukushima Daiichi Nuclear Power Station. The physical design of mobile robot is one of the main challenges to implement robotic system in USAR operation. The ability to manouver and negotiate with rough terrain is highly essential. In addition, the physical design is also need appropriate sensors in order to sense the environment. Therefore, the overall mechatronic structure must consist a robust platform equipped with sensors and actuators and able to navigate seemlessly on extreme rough terrain as well as perform designated task (e.g., find survivors, clean debris or conduct onsite disaster assessment). In order for a mobile robot to operate in unknown world such as USAR environment, it is crucially important for the mobile robot to have certain level of autonomy to plan a desired behaviour and act according to the surrounding. Eventhough it is very challenging to program a mobile robot for this type of environment, a comprehensive control architecture provide a systematic overview of the overall programming structure whilst simplifiying the programming procedure. On top of that, the ability of the overall robot system to plan and track its mission is clearly present in the control architecture. Navigation problem, which is one of the common problem in any exploration robot, also can be solved systematically. In general navigation task, a mobile robot is required to move according to the prior designated trajectory, normally in 2-dimension (flat surface). However, a mobile robot that is design for the USAR operation should be able work and navigate in unknown, uncertain and complex environment. This thesis describes the development of a mobile robot system motivated by the shape-shifting or variable geometry tracked vehicle (VGTV) configuration. The mobile robot is designed with expectation to be able to traverse on various types of terrain and enhance stability to prevent tip-over mishap. The practical work is evaluated by experimental trials on prepared terrains such as staircase, ramp and curb. On top of that, the control framework is outlined to set the objectives of the mobile robot system based on the control hierarchy. This set of works is further simulated with the aim to solve navigation problems as well as to determine the mobile robot behaviour when it is required to travel on uneven surface.

Drifter-style tourism in Asia has become a sanitised and institutionalised tourism alternative. Similar to its counterparts on other continents, it now represents a curious mix of rebellion and conformity, rite of passage and a way of life. Over the last thirty years it has developed its own tourism myth and spawned a mobile subculture of Western travellers. This travelling subculture seeks experiences and insights into other cultures beyond the reach of conventional mass tourism and perpetuates the myth of the traveller as an intrepid explorer. As it has evolved, the subculture has begun to appeal to a far wider cross-section of Western society than ever before and has become a mass phenomenon itself. Contrary to mass tourism, it offers not a holiday but an experiential physical and psychological journey for those inclined to go. Its effect on the traveller is of an existential rather than transitory nature and has the potential to significantly alter the future course of an individual's life. With rapidly increasing numbers. the subculture now represents a viable market in its own right. one that fits in nicely with a balanced tourism product. However, development of this tourism alternative is continuously being undermined by the cannibalisation of its destination sites by other tourism sectors. The existence of a flourishing subcultural centre frequently invites a "hostile take-over" of local tourism structures by outside operators and competing tourism sectors. The thesis will argue that Western travellers now represent an institutionalised alternative to mass tourism and, as such, comprise a significant part of the international tourism market. It will further assert that for a given destination to achieve a balanced tourism product and to maximise economic returns, the ongoing cannibalisation of subcultural destinations by other tourism sectors is both unnecessary and undesirable.

Master of Science
Department of Computing and Information Sciences
Daniel Andresen
Finding a desired off-campus home could be a difficult task for incoming students at K-State. This cross platform mobile application can help students in this task. This mobile application will serve as platform for students and home owners to find, list and review a property. Users can create their personal account and manage their profile and properties they listed. They can post multiple property listings with the key details and these listings will be visible to all the other users. To avoid spam and repetitive postings there is an address verification system in place. While posting a property listing the address is verified with Google maps database. If Google maps fail to identify the address or if that address is already listed, the user will not be allowed to list that property. Users can see all the property listings and their details including a Google map location image, a link to navigate to the address, contact details of the owner, reviews of other users. Users can rate a property from 1(low) to 5(high) along with an optional review. The review and rating can help other user to select a desired place to live. The user interface is developed with web technologies and using Cordova the same code can be used to convert it into a mobile application for both iOS and Android which makes this application platform independent and easily available.

The purpose of this thesis is to evaluate the possibility of predicting difficulty, measured in average human success rate (AHSR), across game levels of a mobile game using a general AI algorithm. We implemented and tested a simulation based bot using MCTS for Candy. Our results indicate that AHSR can be predicted accurately using MCTS, which in turn suggests that our bot could be used to streamline game level development. Our work is relevant to the field of AI, especially the subfields of MCTS and single-player stochastic games as Candy, with its diverse set of features, proved an excellent new challenge for testing the general capabilities of MCTS. The results will also be valuable to companies interested in using AI for automatic testing of software.

With the introduction and rapid rise of mobile computing, the multi tasking phenomenon has impinged mobile environments. Currently, mobile devices enable and induce multitasking on the move by taking tasks into mobile environments and encouraging interaction through prompts. But they are al so inhibitors because they fail to support effective, efficient, and enjoyable multitasking. This failure can be traced back to challenges arising from being mobile and to challenges arising from mobile devices. Mobile device users encounter constantly changing mobile contexts, which results in interruptions and unpredicted incidents, distractions, and fluctuations. These lead to increasingly fragmented interaction s. Moreover, these challenges are not addressed by current mobile technologies, which are plagued by issues of " miniaturisation" of mobile devices and their persisting reliance on Graphic User Interface (GUI) metaphors. This thesis aims to develop novel mobile interfaces that support, rather than inhibit, multitasking behaviour on the move. Indeed, it argues that a new direction is required to support mobile interactions by minimising the demands placed upon the human cognitive system caused by interaction tasks and adapting interactions to the context the user is currently in . To achieve this, two approaches from the field of Human-Computer Interaction (HCI), Minimal Attention User Interfaces and context-awareness. A Minimal Attention User Interface (MAUI), taking the form of a multimodal interface, allows for natmal and flexible interaction and reduces the attention taken away from mobility tasks by using complementary modalities rather than disruptive modalities for interaction tasks. To exploit the natural capabilities for human multitasking, cognitive resource theories from the field of Human factors play a central role in the design of such a multimodal interface. The promise of context-aware systems me also harnessed by enabling context-sensitive selection of communication modalities through the recognition of typical mobility tasks.

With the emergence and growing popularity of online social networks, depth sensors (such as Kinect), smart phones /tablets, wearable devices, and augmented reality (such as Google Glass and Google Cardboard), the way in which people interact with digital media has been completely transformed. Globally, the apparel market is expected to grow at a compound annual growth rate of 5 between 2012 and 2025. Due to the huge impact for ecommerce applications, there is a growing interest in methods for clothing retrieval and outfit recommendation, especially efficient ones suitable for mobile apps. To this end, we propose a practical and efficient method for mobile visual clothing search and implement it as a smart phone app that enables the user to capture a photo of clothing of interest with their smart phone and retrieve similar clothing products that are available at nearby retailers. Furthermore, we propose an extended method where soft biometric clothing attributes are combined with anthropometrics computed from depth data for person identification and surveillance applications. This addresses the increased terrorist threat in recent years that has driven the need for non-intrusive person identification that can operate at a distance without a subject’s knowledge or collaboration. We implement the method in a wearable mobile augmented reality application based on a smart phone with Google Cardboard in order to demonstrate how a security guard could have their vision augmented to automatically identify a suspect in their field of vision. Lastly, we consider that a significant proportion of photos shared online and via apps are selfies and of dressed people in general. Hence, it is important both for consumers and for industry that systems are developed to understand the visual content in the vast datasets of networked content to aid management and perform smart analysis. To this end, this dissertation introduces an efficient technique to segment clothing in photos and recognize clothing attributes. We demonstrate with respect to the emerging augmented reality field by implementing an augmented reality mirror app for mobile tablet devices that can segment a user’s clothing in real-time and enable them to realistically see themselves in the mirror wearing variations of the clothing with different colours or graphics rendered. Empirical results show promising segmentation, recognition, and augmented reality performance.

This dissertation studies the context-aware application with its proposed algorithms at client side. The required context-aware infrastructure is discussed in depth to illustrate that such an infrastructure collects the mobile user’s context information, registers service providers, derives mobile user’s current context, distributes user context among context-aware applications, and provides tailored services. The approach proposed tries to strike a balance between the context server and mobile devices. The context acquisition is centralized at the server to ensure the usability of context information among mobile devices, while context reasoning remains at the application level. Hence, a centralized context acquisition and distributed context reasoning are viewed as a better solution overall. The context-aware search application is designed and implemented at the server side. A new algorithm is proposed to take into consideration the user context profiles. By promoting feedback on the dynamics of the system, any prior user selection is now saved for further analysis such that it may contribute to help the results of a subsequent search. On the basis of these developments at the server side, various solutions are consequently provided at the client side. A proxy software-based component is set up for the purpose of data collection. This research endorses the belief that the proxy at the client side should contain the context reasoning component. Implementation of such a component provides credence to this belief in that the context applications are able to derive the user context profiles. Furthermore, a context cache scheme is implemented to manage the cache on the client device in order to minimize processing requirements and other resources (bandwidth, CPU cycle, power). Java and MySQL platforms are used to implement the proposed architecture and to test scenarios derived from user’s daily activities. To meet the practical demands required of a testing environment without the impositions of a heavy cost for establishing such a comprehensive infrastructure, a software simulation using a free Yahoo search API is provided as a means to evaluate the effectiveness of the design approach in a most realistic way. The integration of Yahoo search engine into the context-aware architecture design proves how context aware application can meet user demands for tailored services and products in and around the user’s environment. The test results show that the overall design is highly effective,providing new features and enriching the mobile user’s experience through a broad scope of potential applications.

Esta tese reflete sobre um processo específico: a transmídia e seu potencial de criar novas possibilidades interativas e artísticas apropriando-se dos ambientes digitais. A disseminação tecnológica no cotidiano das pessoas nas últimas décadas alavanca uma proliferação e diversidade de mídias que propiciam um ambiente fértil para desenvolvimento de processos transmidiáticos. Apesar de a transmídia não ser um fenômeno novo, as novas possibilidades que o ambiente digital hiperconectado e rico em novas mídias e interfaces traz são inúmeras, não apenas nas áreas das artes, mas também em quaisquer áreas que envolvam comunicação, informação e interação. Novos modos de interação trazem consigo novas possibilidades, tanto quanto novos desafios. O foco deste trabalho é o contexto atual transmidiático e as oportunidades e desafios emergentes de seu uso. O escopo compreende também a apresentação e análise de algumas obras de arte que se beneficiaram do uso da transmídia como processo fundamental para seu desenvolvimento, razão pela qual não seriam possíveis em outro cenário que não o transmidiático atual. Foram desenvolvidos pela autora quatro trabalhos de arte como experimentação transmídia que refletem os resultados obtidos.
This thesis reflects about a particular process: the transmedia and its potential to create new interactive and artistic possibilities that appropriate from the digital environments. The technological dissemination in people\'s daily lives in the past decades leverages a media proliferation and diversification that propitiate a fertile environment for the development of transmedia processes. Although transmedia is not a new phenomenon, the new possibilities that the actual digital environment provide -- hiper-connected and rich in new media and interfaces -- are countless, not only in the field of Arts, but also in any other areas related to communication, information and interaction. New interactive modes bring with themselves new possibilities as much as new challenges. The focus of this work is the emergent transmedia context and the opportunities and challenges that rise from its use. The scope here also involves the presentation and analysis of some artworks that take advantage from the use of transmedia as a fundamental process to their development, not being able to exist in any other scenario than the present one. It was developed by the author four artworks as transmedia experimentation that reflect the achieved results.

In this thesis we look at mobile agent solutions to black hole search and related problems. Mobile agents are computational entities that are autonomous, mobile, and can interact with their environment and each other. The black hole search problem is for a team of these agents to work together to map or explore a graph-like network environment where some elements of the network are dangerous to the agents. Most research into black hole search has focussed on finding a single dangerous node: a black hole. We look at the problem of finding multiple black holes and, in the case of dangerous graph exploration, multiple black links as well. We look at the dangerous graph exploration problem in the network model. The network model is based on a normal static computer network modelled as a simple graph. We give an optimal solution to the dangerous graph exploration problem using agents that start scattered on nodes throughout the network. We then make the problem more difficult by allowing an adversary to delete links during the execution of the algorithm and provide a solution using scattered agents. In the last decade or two, types of networks have emerged, such as ad hoc wireless networks, that are by their nature dynamic. These networks change quickly over time and can make distributed computations difficult. We look at black hole search in one type of dynamic network described by the subway model, which we base on urban subway systems. The model allows us to look at the cost of opportunistic movement by requiring the agents to move using carriers that follow routes among the network's sites, some of which are black holes. We show that there are basic limitations on any solution to black hole search in the subway model and prove lower bounds on any solution's complexity. We then provide two optimal solutions that differ in the agents' starting locations and how they communicate with one another. Our results provide a small window into the cost of deterministic distributed computing in networks that have dynamic elements, but which are not fully random.

Orientador: Eduardo Alves do Valle Junior
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-27T09:45:59Z (GMT). No. of bitstreams: 1 HidalgoFlores_PaulJoseph_M.pdf: 28047685 bytes, checksum: 055aafb9f31fc0ba5c1cfac1cc7a79b3 (MD5) Previous issue date: 2015
Resumo: Aplicações de busca visual em aparelhos móveis (Mobile Visual Search ¿ MVS) tornaram-se possíveis devido ao alto poder computacional e a multiplicidade de sensores dos novos dispositivos móveis (smart-phones, tablets). Além disso, o estado da arte em recuperação de informação multimídia baseada no conteúdo (Content Based Image Retrieval - CBIR) alcançou uma maturidade que permite realizar estas tarefas de forma eficiente. Nesta dissertação, apresentamos um estudo das principais técnicas em CBIR visual das imagens. Uma vasta investigação da literatura foi realizada, que inclui desde os descritores baseados em gradiente mais comuns aos mais recentes descritores binários e compactos. Como resultado da análise comparativa entre as principais técnicas no contexto de MVS, apresentamos as alternativas mais apropriadas para serem utilizadas em tais aplicações
Abstract: Mobile Visual Search (MVS) applications became possible due to the computational power and multiple sensors on current mobile devices (smart-phones, tablets). In addition, the state-of-the-art in content based image retrieval (CBIR) has reached a maturity to perform these tasks efficiently. In this dissertation, we present a study of the major techniques in CBIR. An extensive study of literature, including the most common descriptors based on gradients and the recently proposed binary descriptors. As a result of comparative analysis between the main techniques in the context of MVS, we present the most appropriate alternatives to use in such applications
Mestrado
Engenharia de Computação
Mestre em Engenharia Elétrica

In January, 2012, the Supreme Court of the United States refused to hear three cases involving student online speech, or cyberspeech. This indicates that the Court is content with lower courts applying First Amendment jurisprudence developed over 40 years ago to a rapidly advancing digital environment where students carry the equivalent of personal computers in their pockets, have an ever-growing telepresence, and rely on cyberspeech as their primary means of communicating with the world around them. Lower courts also are beginning to grapple with challenges to students Fourth Amendment right to be free from unreasonable search and seizure as it relates to the digital environment described above. Recently, lower courts in Mississippi, Texas, Minnesota, and Kentucky have applied standards set forth decades ago to decide cases involving searches of students mobile devices and Web 2.0 applications. Given the absence of guidance from the Supreme Court, this study aims to: (1) identify and analyze trends in the current application of legal standards related to student cyberspeech and search and seizure in the digital age; (2) synthesize these findings into a set of essential guidelines for school officials to use as they navigate a legal landscape that has yet to be well defined; and (3) make recommendations to further develop the body of law. Findings indicate that school officials have the legal authority to restrict off-campus student cyberspeech when certain conditions are met, and Tinker governs cases in this area. Seriously threatening, slanderous, or obscene cyberspeech is not constitutionally protected and can be restricted prior to an actual disruption. Off-campus student cyberspeech that reaches the school can legally be restricted so long as evidence shows that it caused a material and substantial disruption. In addition, students possess reasonable expectations of privacy in their personal mobile devices and password-protected private Web 2.0 communications. T.L.O governs searches of students personal mobile devices and Vernonia appears to govern cases involving searches of students Web 2.0 applications. Substantive suspicion at the outset, carefully tailored searches, and a clear governmental interest will keep school officials from violating students Fourth Amendment protections.
Ed. D.

The purpose of this thesis is to research marketing video games for mobile devices that are releaesd through app stores. The intention is to identify the key factors in the consumer decision process for the casual mobile game audience regarding how they obtain information about apps and identify locations for mobile games to gain more visibility.

Nous nous intéressons dans cette thèse à la modélisation et à la vérification de systèmes d'agents mobiles. Le développement d'une structure pour les agents mobiles demande le développement de solutions pour un ensemble de problèmes spécifiques dû à la mobilité. Une question dans le développement de logiciel est : le programme proposé est-il vraiment une solution pour le problème considéré. Une façon de répondre à cette question consiste à utiliser les méthodes formelles. Dans notre approche, nous construisons un modèle du problème (la spécification) en uitilisant le Pi calcul d'ordre supérieur. En ayant ce modèle formel comme base, Nous pouvons vérifier que ce modèle possède les propriétés voulues ; valider le modèle à travers es simulations ; être capable de prouver que l'implémentation est cohérente par rapport à la spécification. En profitant de nos résultats, nous avons implémenté un prototype qui permet la validation de systèmes d'agents mobiles conçus avec le Pi-calcul d'ordre sup
This thesis deals with the modelling and validation of mobile agent systems. The development of a support structure for mobile agents demans the development of solutions for set of specific problems that appear due to mobility. A basic question in software development is if the proposed program is really a solution for the considered problem. One way to answer this question is through the use of formal methods. In our approach, the first step is to build a model of the solution (specification) using the higher-order Pi-calculus. Having this formal model as a base, we can : validate the model through simulations ; carry out mathematical tests to guarantee that this model possesses the required properties (verification) ; being able to prove that the implementation is correct with respect to the specification. Making use of our results, we have implemented a prototype called HOPiTool which allows the possibility of validation of mobile agent systems conceived with higher-order Pi-calc

A common problem in existing Search And Rescue (SAR) systems is that they must be activated by the missing person in order to work. This requires an awareness of the the risk of becoming distressed, which in many cases is not feasible. Furthermore, most of the localization systems require specialized hardware.In this thesis, the victim is assumed to wear a cellphone that could be located using readily available consumer electronics. A method of estimating the position of a transmitter, given radio signal measurements at different locations, is developed and verified with real and simulated data. A proof-of-concept system is built in which several users can jointly collect received signal strength data at different locations using mobile phones. The system analyzes the data in real-time and guides the users in the search by estimating the origin of the signal.An outdoor field test is conducted in which the searchers using the system are able to locate the hidden target phone without prior knowledge regarding the position. We are able to localize the victim with an accuracy of 10-20 meters in a timely manner using android smartphones. This shows the potential of a similar system in \abbrSAR scenarios. However, more work is needed to make the system viable in real scenarios and to remove some of the delimitations of the current implementation.

The aim of this study is to develop a search tool for roads for mobile GIS application. The satellite image of Ankara is the base map of program. There is also a search option for the roads. The application is based on open source libraries, which are ECW for imagery and SQLite for the database of vector. The application is coded in Embedded Visual C++. The study shows that mobile GIS applications can be prepared by the help of open source libraries. There is no need to buy a commercial product to mobilize the GIS.

In this thesis work, a mobile robot is designed to be used in search and rescue operations to help the human rescue workers. The difficult physical conditions in the ruins obstruct the movement. Therefore, it is aimed to design a search and rescue robot which can move easily on rough terrain and climb over the obstacles. The designed robot is made up of three modules. A connecting unit is designed that is situated between each module. This connecting unit which is composed of two universal and one revolute joint gives 5 DOF relative motions to the modules. On the other hand, the wheel&rsquo
s continuous contact with the ground is important while moving on rough terrain. In order to increase the adaptation of the robot to the rough terrain the rear axle is connected to the body with a revolute joint. Besides, skid steering system is used in the design of the robot to attain a compact and light solution which requires few parts. In the study, kinematic equations and dynamic equations of the robot are obtained to be used by the control program. The dynamic equations are obtained by using the Newton &ndash
Euler formulation. The forces, which are transmitted by the connecting unit to the modules, and the reaction forces formed between the wheels and the ground are derived by using these equations. &ldquo
Follow-the-Leader approach&rdquo
is used as a control strategy to make the modules move in formation and to reduce the tracking problem. In this approach, the first module is the leader and the second and third modules follow it. A Matlab program is written to control the robot by using the constructed mathematical model of the robot. The reaction forces between the wheels and the ground are calculated through using the Matlab program written. Moreover to make the simulations of the robot for some cases, a model is constructed in ADAMS program.

Personal robots with autonomy, mobility, and manipulation capabilities have the potential to dramatically improve quality of life for various user populations, such as older adults and individuals with motor impairments. Unfortunately, unstructured environments present many challenges that hinder robot deployment in ordinary homes. This thesis seeks to address some of these challenges through a new robotic sensing modality that leverages a small amount of environmental augmentation in the form of Ultra High Frequency (UHF) Radio-Frequency Identification (RFID) tags. Previous research has demonstrated the utility of infrastructure tags (affixed to walls) for robot localization; in this thesis, we specifically focus on tagging objects. Owing to their low-cost and passive (battery-free) operation, users can apply UHF RFID tags to hundreds of objects throughout their homes. The tags provide two valuable properties for robots: a unique identifier and receive signal strength indicator (RSSI, the strength of a tag's response). This thesis explores robot behaviors and radio frequency perception techniques using robot-mounted UHF RFID readers that enable a robot to efficiently discover, locate, and interact with UHF RFID tags applied to objects and people of interest. The behaviors and algorithms explicitly rely on the robot's mobility and manipulation capabilities to provide multiple opportunistic views of the complex electromagnetic landscape inside a home environment. The electromagnetic properties of RFID tags change when applied to common household objects. Objects can have varied material properties, can be placed in diverse orientations, and be relocated to completely new environments. We present a new class of optimization-based techniques for RFID sensing that are robust to the variation in tag performance caused by these complexities. We discuss a hybrid global-local search algorithm where a robot employing long-range directional antennas searches for tagged objects by maximizing expected RSSI measurements; that is, the robot attempts to position itself (1) near a desired tagged object and (2) oriented towards it. The robot first performs a sparse, global RFID search to locate a pose in the neighborhood of the tagged object, followed by a series of local search behaviors (bearing estimation and RFID servoing) to refine the robot's state within the local basin of attraction. We report on RFID search experiments performed in Georgia Tech's Aware Home (a real home). Our optimization-based approach yields superior performance compared to state of the art tag localization algorithms, does not require RF sensor models, is easy to implement, and generalizes to other short-range RFID sensor systems embedded in a robot's end effector. We demonstrate proof of concept applications, such as medication delivery and multi-sensor fusion, using these techniques. Through our experimental results, we show that UHF RFID is a complementary sensing modality that can assist robots in unstructured human environments.

Since social media gains ever increasing popularity, Online Social Networks have become important repositories for information retrieval. The concept of social search, therefore, is gradually being recognized as the next breakthrough in this field, and it is expected to dominate topics in industry. However, retrieving information from OSNs with high Quality of Experience is non-trivial as a result of the prevalence of mobile applications for social networking services. For the sake of shortening user perceived latency Web caching was introduced and has been studied extensively for years. Nevertheless, the previous works seldom focus on the Web caching solutions for social search. In the context of this master’s thesis project, emphasis is given to the design of a Web caching system which is used to cache public data from social media with the objective of improving the user experience in terms of the freshness of data and the perceived service latency. To be more specific, a Web caching strategy named Staleness Bounded LRU algorithm is proposed to limit the term of validity of the cached data. In addition, a Two-Level Web Caching System that adopts the SB-LRU algorithm is proposed in order for shortening the user perceived latency. Results of trace-driven simulations and performance evaluations demonstrate that serving clients with stale data is avoided and the user perceived latencies are significantly shortened when the proposed Web caching system is used in the use case of unauthenticated social search. Besides, the design idea in this project is believed to be helpful to the design of a Web caching system for social search, which is capable of caching user specific data for different clients.

Local feature detection and its applications in different problems are quite popular in vision research. In order to analyze a scene, its invariant features, which are distinguishable in many views of this scene, are used in pose estimation, object detection and augmented reality. However, required performance metrics might change according to the application type
in general, the main metrics are accepted as accuracy and computational complexity. The contributions in this thesis provide improving these metrics and can be divided into three parts, as local feature detection, local feature description and description matching in different views of the same scene. In this thesis an efficient feature detection algorithm with sufficient repeatability performance is proposed. This detection method is convenient for real-time applications. For local description, a novel local binary pattern outperforming state-of-the-art binary pattern is proposed. As a final task, a fuzzy decision tree method is presented for approximate nearest neighbor search. In all parts of the system, computational efficiency is considered and the algorithms are designed according to limited processing time. Finally, an overall system capable of matching different views of the same scene has been proposed and executed in a mobile platform. The results are quite promising such that the presented system can be used in real-time applications, such as augmented reality, object retrieval, object tracking and pose estimation.

Le support d'applications par lesréseaux mobiles ad-hoc (MANET) exige la prise en compte de la qualité de service (QoS). Les exigences de QoS peuvent être exprimées en termes de bande passante (vidéoconférence) ou de délai de bout-en-bout (voix sur IP). Dans cette thèse nous montrons pourquoi les solutions des réseaux filaires ne sont pas applicables telles quelles aux réseaux mobiles ad-hoc. La présence des interférences radio, les capacités limitées des ressources réseau et la mobilité des noeuds en sont les raisons majeures. Nous proposons une solution permettant doffrir une différentiation de service dans les réseaux ad-hoc tout en tenant compte des interférences. Cette solution est constituée de quatre composantes à savoir le modèle QoS, le contrôle d'admission, le routage avec QoS et l'ordonnancement
The support of applications by the mobile ad-hoc networks (MANET) requires to taking into account the quality of service (QoS). QoS requirements can be expressed in terms of bandwidth (videoconference) or in terms of end-to-end delay (voice on IP). In this thesis we show why the solutions of wired networks are not applicable just as they are to the mobile ad-hoc networks. The presence of the radio interferences, the limited network resources and the node's mibility are the major reasons. We propose a solution taking into account radio interferences and allowing a service differentiation in the mobile ad-hoc networks. This solution is made up of four components which are : the QoS model, the admission control, the QoS routing and the QoS Scheduling

For a mobile application with focus on search functionality to be able to run smoothly, it is important to provide relevant search result based on user input. This report is to investigate how to implement a search function, to provide appropriate answers. The project consists of developing a recipe application with basic functions. The focus will be towards the search algorithm, how it will be designed. To find out what users consider is relevant, a study is done with 88 participants. The results of the survey were evaluated, and remained as an underlay for what should be searchable and how to implement the search function. Creating a good search function proved to consumes a lot of time and resources. The mobile application was completed with the desired functionality, which was provided from the survey.
För att en mobilapplikation med fokus på sökfunktionalitet ska fungera väl, är det viktigt att sökfunktionen ger relevanta resultat baserat på användarens sökningar. Den här rapporten har i syfte att undersöka sökfunktionen kan implementeras för att ge relevant svar. Projektet består av att utveckla en receptapplikation med grundläggande funktionalitet, där fokus är hur sökalgoritmen ska utformas. För att ta reda på vad användare anser relevant har en undersökning gjorts med 88 deltagare. Resultatet av undersökning har utvärderats och legat som underlag för vad som ska vara sökbart samt hur denna sökfunktion bör implementeras. Att skapa en bra sökfunktion visade sig vara både resurs- och tidskrävande. Mobilapplikationen färdigställdes med önskad funktionalitet, där sökningsalternativen är baserade på vad undersökningen visade.