Orientador: Celso de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T23:28:24Z (GMT). No. of bitstreams: 1 Frison_CelsoIwata_M.pdf: 5336693 bytes, checksum: bde1ddd7684a93de5f398e08705c6bb0 (MD5) Previous issue date: 2009 / Resumo: Dentre as técnicas de detecção multiusuário existentes em sistemas CDMA, a técnica conhecida como ótima é a responsável por gerar a menor probabilidade de erro de símbolo possível. Porém, o desempenho referente a esta técnica é obtido através de uma elevada complexidade em número de cálculos, o que leva à sua impraticabilidade em sistemas reais. Com isso, um detector multiusuário sub-ótimo que utiliza limiares de confiabilidade nas amostras recebidas para classificá-las como confiáveis ou não-confiáveis é proposto em um ambiente CDMA síncrono. Cada uma destas amostras já classificadas, recebe um processamento diferenciado na detecção. A introdução de limiares de confiabilidade na detecção multiusuário demonstrou que um desempenho equiparável ao de um detector multiusuário ótimo pode ser possível, e ao mesmo tempo com uma menor complexidade em número de cálculos realizados. Uma modelagem matemática foi desenvolvida para a obtenção das equações de complexidade em número de cálculos e da probabilidade de erro de bit. Estas expressões analíticas foram validadas através de simulações realizadas. / Abstract: Among all the existing multiuser detection techniques in CDMA systems, the one which gives the minimum symbol error probability is called optimum. Conversely, the performance of this technique is obtained with a high complexity in the number of calculations, which make this technique impracticable in real systems. Then, a sub-optimum multiuser detector which applies reliability thresholds to the received samples, to classify them as reliable or nonreliable, is proposed in a synchronous CDMA system. Each one of these samples that has been already classified receives a different management in the detection process of the bits. The insertion of these reliability thresholds in the multiuser detection showed that a performance similar to the optimum multiuser detector could be achieved, and at the same time, with a significant reduction in the number of calculations (detector's complexity). Theoretical equations of complexity an bit error rate are presented. These theoretical expressions are tight when compared to the respective simulations. / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Economic crime is always actual theme, even more when economy finds itself in crisis. It is a well-known fact, that in such times fraud risk increases even inside organizations. This thesis is dealing with economic crime from the perspective of auditor and fraud examiner and likewise in the terms of Czech criminal law. Fraud, as both professions call economic criminality, implies higher costs for organizations, that's why both private and government sector organizations strives to fight it. Statutory audit is being perceived as one of the means to detect fraud. But statutory audit often fails to satisfy these expectations, for it's objective is only in auditor's opinion to express, that financial statement doesn't contain material misstatement. Detecting fraud is a responsibility of the entity. As a result of discrepancies in concept of this responsibility between public and auditors arises expectation gap, which is one of the problems distinctly revealed in the beginning of the financial crisis, when big companies, whose financial statements were verified by auditor's unqualified opinion, found themselves in trouble. In this context the thesis specifies auditor's responsibility in the wording of International Standards on Auditing and Czech law. As more efficient anti-fraud means the forensic audit is being used, the thesis compares it with statutory audit especially in terms of detecting fraud.

L’évolution des référentiels spatio-temporels et les dernières avancées des systèmes d’information géographique ont favorisé l’apparition de nouveaux types de services et d’applications liés à la localisation et à la mobilité d’entités d’intérêt dont la supervision et le contrôle d’objets mobiles en temps réel.Ces constats nous ont conduit à nous intéresser en tout premier lieu aux évolutions des objets qui peuvent être envisagées sous forme de trajectoires et offrent de nouvelles perspectives quant à l’analyse en temps réel de leurs comportements particuliers individuels et/ou collectifs.Dans le contexte industriel de l’entreprise Intactile Design, un enjeu majeur émerge : il s’agit de mettre à la disposition de tout expert, amené à prendre une décision au cours d’opérations de surveillance, le plus d'informations possibles relatives au contexte environnant les objets mobiles afin d’en extraire celles permettant la détection de comportements remarquables.L’objectif est donc d'analyser et d'exploiter la masse de données acquises à partir du suivi d'objets mobiles de divers types, et plongés dans des contextes différents de supervision. Pour ce faire, nous proposons une approche générique déclinable sur divers cas de supervision partant de l'hypothèse qui consiste à envisager, pour tout objet mobile, une seule et même trajectoire tout au long de sa vie.L'une des problématiques principales de cette recherche relève des difficultés d'interprétation des données recueillies en temps réel issues de l'observation des objets. En effet celles-ci sont massives, de compositions variables et parfois incomplètes, possiblement redondantes, voire sémantiquement hétérogènes. L'idée est de s’affranchir du manque de sémantique contextuelle et de l’absence de maîtrise des informations liées à l’analyse et à l’exploitation de ces données.L’approche consiste à proposer le recours à une ontologie cadre à des fins d’enrichissements des observations et analyses, et ce pour aider à la détection de comportements d'objets mobiles. L’ontologie cadre représente l'objet mobile et sa trajectoire au sein de tout contexte de supervision et ce de manière générique. Ce modèle s'inspire de travaux existants autour de la modélisation de données spatiales comme temporelles et les étend pour répondre à la spécificité de l’analyse sémantique en temps réel de la mobilité des objets. Pour rendre compte de la spécificité des différents contextes de supervision, l'ontologie est complétée par des règles métiers construites avec l'aide des experts du domaine. L'idée est tout à la fois de disposer d'une représentation de connaissances la plus expressive possible sans augmenter pour autant le coût du raisonnement ; et de rendre l'approche adaptable à toute thématique liée à la supervision.L'approche modulaire spécifiée a ensuite été mise en application au sein d'un prototype logiciel général qui fonctionne comme un système à base de connaissances. Il assure la structuration, enrichissement, extraction et analyse spatio-temporelle des connaissances conformes à notre modèle ontologique et donc offre les éléments nécessaires à la compréhension de comportements remarquables définis par les experts des domaines ciblés.Nous illustrons notre approche au travers d’un cas d’étude concret relatif au domaine des systèmes de supervision des opérations de défense terrestre. / The recent evolution of gazetteers and the latest advances in geographic information systems have promoted new types of services related to the location and mobility of entities of interest, including the real-time supervision and control of moving objects.On the strength of these facts, we are considering the motion of an object based on its trajectory (i.e., the path followed by this object in motion). At our sense, the modeling of trajectories of a number of moving objects offers new insights into real-time analysis of their individual and/or group specific behaviors.Within the industrial context of the company Intactile Design, enhancing decision making in real time for supervision purposes, turns out to be a major challenge. At the same time, much emphasis is being placed on making sure any accessible data, related to the context of the moving objects, are available to experts in order to fully support decision making processes. More importantly, the key idea is to find a strategy that enhances capabilities of detecting unusual behaviors whilst integrating some kind of valuable information related to the context.Consequently, the main objective is to collect and analyze all of the data acquired from the tracking of many different types of moving objects in a variety of supervision contexts.At this effect, we propose a generic and innovative approach that can be applied to any case of supervision based on the assumption that considers for every mobile object, a single and unique trajectory constantly changing over time.One of the main obstacles of this research is the difficulty of real-time interpreting of all of the collected data as these data are mostly complex, voluminous, semantically heterogeneous and incomplete.In this way, the idea is to overcome the lack of contextual semantics (i.e., semantics captured from the observations of the objects evolving within their contexts).To address these challenges, we propose a top domain ontology for moving objects and their trajectories, which is expressed in OWL 2 DL. The ontology attempts to describe the starting categories for the field of mobility and therefore is applicable to all supervision and control contexts.Additionally, this ontology is building upon a few number of existing ontologies that all refer to spatio-temporal knowledge, including GeoSPARQL and OWL Time.Moreover, the ontology and a set of business rules, provided by the experts on a domain of interest, are combined to fully capture the contextual semantics of the domain under consideration.The aim is double: on one side, to benefit from a knowledge representation as expressive as possible that offers a cost-effective reasoning, and on the other side to efficiently adapt the approach to any context related to supervision.Our modular approach is implemented through a general software prototype that runs as a knowledge-based system.The prototype ensures the sustainability, extraction and spatio-temporal reasoning of information that complies with our ontology, and therefore it offers the necessary elements to understand behaviors defined by the experts of the targeted areas.We illustrate our approach through a concrete case study of monitoring systems dedicated to land defense.

Revisorns roll har på senare tid kommit att innefatta mer än att säkerställa de finansiella talensriktighet. En stor del av revisorns arbetsuppgifter handlar om att tillstå sina klienter med alltyp av rådgivning. En följd av revisorns utökade arbetsuppgifter är att det ställer krav pårevisorn att inneha kunskap om en rad olika ämnen. Denna utveckling har kommit attinnebära att allmänheten anses ha höga förväntningar på revisorn i dess yrkesroll.Tidigare forskning visar att bedrägerier inom organisationer har ökat på senare tid och att dethar kommit att bli ett ökat problem i samhället. I och med indikationer på att bedrägerier iorganisationer har ökat anses allmänheten också ha förväntningar på att revisorn skallupptäcka bedrägerier när de utför revision. Revisorerna själva anser däremot inte att det är ettsyfte med revisionen att upptäcka eventuella bedrägerier. Forskare menar dock attallmänhetens förväntningar är så pass höga att revisorerna måste ta hänsyn till detta krav.Tidigare forskning samt de tillfrågade revisorerna bekräftar att bedrägerier i företag är mycketproblematiska att upptäcka med hänsyn till det faktum att de inte enskilt har någon storpåverkan på de finansiella räkenskaperna för ett bolag.Meningsskiljaktigheter råder mellan revisorerna och användarna kring revisorns roll och bådetidigare forskning samt de revisorer jag har intervjuat i denna studie vittnar om att det råderett förväntningsgap mellan de olika parterna. En vanlig missuppfattning menar revisorerna imin undersökning är att allmänheten tror att revisorerna reviderar och kontrollerar pådetaljnivå. I både tidigare forskning samt empiriskt underlag finner jag uppfattningen attkunskapen kring revisorns roll måste öka. Tidigare forskning och de tillfrågaderespondenterna är överens om att information är huvudnyckeln till att minska deförväntningsgap som råder och som från revisorernas sida uppfattas som mycket olyckligt.Studien har gjorts i syfte att med kvalitativa semistrukturerade intervjuer med revisorerklargöra hur revisorerna själva ser på sin roll att upptäcka bedrägerier i organisationer.Studien består sammanlagt av åtta respondenter representerade på fyra revisionsbyråer varavtre stycken är stora revisionsbolag och en mindre revisionsbyrå. Resultatet av denna studievisar att revisorerna är överens om att upptäcka bedrägerier inte är ett huvudmål medrevisionen utan utgör endast en del. Revisorerna i studien menar att det är deras uppgift attgranska utifrån väsentlighet och risk. Samtliga respondenter menar att det är ledningensansvar att upptäcka bedrägerier men framförallt betonar de vikten av att förebyggabedrägerier med hjälpa av goda interna kontroller. / Program: Civilekonomprogrammet

Volatile organic compounds (VOCs) in air and heavy metal ions, anions, microorganism in water are environmental contaminants that require detection at certain low concentrations to avoid detrimental effects. Analytical instruments can accurately determine the concentration and composition of the contaminants at trace levels. However, these methods require skilled personnel to operate. Hence sensors should have fast response, low maintenance and easy to handle. In the present work, environmental monitoring sensor for volatile organic compounds, anion and E. coli was developed. The sensor is resistive sensor architecture with organic nanocomposite as sensing layer. The conjugated organic molecule with receptor moieties that can interact and exhibit affinity to each of the analyte was designed and synthesized. A new conducting polymer for sensing toluene, aldehyde is designed and fabricated. The sensor shows highest sensitivity and selectivity for targeted analyte. The sensor response is explained by molecular dynamics simulation. The solubility parameter of the new polymers is calculated by molecular dynamics and is used for elucidation of rationale of the mechanism for selectivity. The interaction energy of the sensing layer calculated by simulation is higher for targeted analyte than that for other analytes. The adsorption of vapors on the sensing layer results in volumetric change of the sensing layer. The effect can be experimentally determined by monitoring the thickness of the film and the change in the parameters such as mass change, capacitance, resistance change, refractive index change that occurs due to absorption of vapors in the polymers. Here, laser Doppler vibrometry, a non contact method is used to measure the displacement occurring due to interaction of a new polymer film with analyte vapors. A sensor for real time monitoring of nitrate ion concentration in water is fabricated. A new conjugated polymer is designed for selection of nitrate is used as a sensing molecule. The sensor is tested for various concentrations of nitrate ions and possible interferents effect. An organic nanocomposite based resistive sensor is designed and fabricated to detect E. coli in water. The organic molecule with receptor groups was selected such that receptor group would interact and exhibit affinity to the functional groups present on outer membrane of the cell wall of the E. coli. The resistance change is caused due to interaction and is because of E. coli acting as p-dopant to sensor molecule. The electrostatic interaction between positively charged amine groups on sensor molecule and negatively charged E. coli is believed to be the interaction mechanism. This work demonstrates that the conjugated molecules with suitable moieties can bind with analyte like VOCs, heavy metal ions, anions, microorganism, that can be used as sensing element in resistive sensor architecture.

This thesis focuses on fraud in the entity, to methods for their detection and possibilities of improving the internal control system so that the risk of offending employee or manager has been reduced to a minimum.

The aim of the thesis is to evaluate the possibilities of evaluation of the risk of accounting frauds and accounting mistakes in the financial statements compiled in terms of Czech accounting standards for their users using analytical tools and methods of the financial analysis. Part of the thesis is the proposal of concrete tools or models that reduce the asymmetry of information between the makers of the financial statements and other users of the financial statements and can be implemented in the internal control system of the unit when decision-making on the financial health of selected accounting units. For practical part was chosen an enterprise with a long tradition. Monitoring ratios of The Beneish Model M-Score detect risk areas and tracking ratio trend may alert management to instability in the financial statement. Liquidity and debt ratios are also appropriate methods for reducing the information asymmetry.

The main aim diploma thesis was the evaluation possibilities of detection accounting fraud and misstatements in financial reports for the managing business corporations. Diploma thesis is divided into two main chapters on literature search and practical. Part of this work was the analysis of techniques and models of of detection performed on a case study of a selected accounting unit. For of individual models calculations were used accounting data from financial statements that were provided by AB, s. r. o. An entity shall compile both financial statements comprehensibly, to give a true and fair view of accounting and financial situation. Risk analysis for of detection manipulation of financial statements, I chose Beneish model, model CFEBT and Jones Nondiscretionary Accruals.

The submitted archeological exploration of area associated with the important battle of the Hussite wars near Lipany on May 30, 1434 was primarily focussed on searching for material remains of this short military event. The project is essentially based on field research using the methodology of battlefield archaeology - the most often research approach concerning conflicts in the early modern history both in the Czech Republic and abroad. The field research was preceded by an analysis of written and iconographic sources relating to the Battle of Lipany and Hussite Wars and by a detailed study of historical maps. The detector prospection combined with targeting the findings by GPS coordinate method for more than four years brought approximately forty findings directly or chronologically related to the event being investigated. Most of them are small militaria (crossbow bullets, projectiles for firearms, spur fragments), the set is complemented by small coins and personal items. Findings related to the battle indicate a spatial relationship, they refer to some of the terrain sites that were the scene of different phases of the conflict. The exploration presumably managed to locate the place where the wagon fort of radical Hussite was situated, other sites indicate a relation to combat maneuvers...

The complexity associated with development of networked video games creates a need for tools for verifying a consistent player experience. Some networked games achieve consistency through the lockstep protocol, which requires identical execution of sent commands for players to stay synchronised. In this project a method for testing networked multiplayer lockstep games for synchronisation problems related to nondeterministic behaviour is formulated and evaluated. An integrated fuzzing AI is constructed which tries to cause desynchronisation in the tested game and generate data for analysis using log files. Scripts are used for performing semi-automated test runs and parsing the data. The results show that the test system has potential for finding synchronisation problems if the fuzzing AI is used in conjunction with the regular AI in the tested game, but not for finding the origins of said problems. / Komplexiteten förenad med utveckling av nätverksuppkopplade dataspel skapar ett behov av verktyg för att verifiera en konsistent spelarupplevelse. Vissa nätverksspel hålls konsistenta med hjälp av lockstep-protokollet, vilket kräver identisk exekvering av skickade kommandon för att spelarna ska hållas synkroniserade. I detta projekt formuleras och evalueras en metod för att testa om nätverksuppkopplade flerspelarspel lider av synkroniseringsproblem relaterade till ickedeterministiskt beteende. En integrerad fuzzing-AI konstrueras som försöka orsaka desynkronisering i det testade spelet och generera data för analys med hjälp av loggfiler. Skript används för att utföra halvautomatiserade testkörningar och tolka data. Resultaten visar att testsystemet har potential för att hitta synkroniseringsproblem om fuzzing-AI:n används tillsammans med den vanliga AI:n i det testade spelet, men inte för att hitta de bakomliggande orsakerna till dessa problem.