För att minska framtida problem med läckor på våra ledningsnät är det viktigt att man förnyar dessa. Planeringen av denna förnyelse kallas för förnyelseplanering. En metod i förnyelseplaneringen är så kallad ”riskbaserad förnyelseplanering”. Denna metod syftar till att hitta de ledningar som innebär störst risk. Med hög risk menas: en ledning som har hög sannolikhet för brott, samtidigt som konsekvensen av att ett brott uppstår är stor. Tekniska Verken i Linköping ansvarar för vattenledningsnätet i Linköpings kommun. I sin förnyelseplanering arbetar man på att få fram ett nytt verktyg, kallat ”Knappen”. Ambitionen med ”Knappen” är kunna hitta sina riskledningar med ”endast ett knapptryck”. ”Knappen” är en beräkning som baseras på en mängd indata om sannolikhet och konsekvens. En av faktorerna som ska användas i beräkningen är en uppskattning av reparationskostnaden läckan medför. Denna undersökning har resulterat i en formel för beräkning av denna kostnad. Formeln är baserad på data om tidigare läckor från 2011. De faktorer som formeln visade sig bero på är: vilken marktyp läckan har skett i, hur långt avståndet är, vilken reparationsmetod man måste använda samt ledningens material och diameter. För en läcka i en segjärnsledning med dimensionen 150 mm som måste lagas med en infällning blir reparationskostnaden enligt formeln 118 740 kr om den inträffade i en villagata. Om samma förutsättningar gäller för en läcka i en gjutjärnsledning med dimensionen 100 mm som tätas med en repmuff blir reparationskostnaden enligt formeln 62 060 kr. / Water is an essential resource that we today take for granted. The distribution of drinking water is done with pipes in our water distribution network. These pipes have a limited lifetime and at some point they will rupture, with a leak as a result. The leak can lead to major consequences. Some examples are: disturbance in traffics, damage to property, as well as private individuals and businesses that are without water. Another consequence is the cost itself of repairing the leak, which sometimes is the most severe consequence. To avoid future problems with water leaks, it is important to renew the pipe network. The planning of this renewal is called renewal planning. A method in renewal planning is so-called “risk-based renewal planning”. This method aims to find the pipes that carry the highest risk. A pipe with high risk is a pipe that has high probability of rupturing, at the same time as the consequence of a rupture is great. Tekniska Verken in Linköping is in charge of the water distribution network in Linköping municipality. In their renewal planning they are working on a new tool, called “Knappen”. The ambition with “Knappen” is to be able to find pipes with high risk with “just one touch of a button”. “Knappen” is a calculation based on a variety of input data on probability and consequence. One of the factors to be used in the calculation is an estimate of the repair cost that the leak causes. This study has resulted in a formula for calculating this cost. The formula is based on data about past leaks from 2011. The factors that the formula turned out to depend on is: in which land type the leak has occurred, how far the distance is, which repair method has to be used and also the material and dimension of the pipe.

Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2017-11-01T17:02:12Z No. of bitstreams: 0 / Made available in DSpace on 2017-11-01T17:02:12Z (GMT). No. of bitstreams: 0 / Este trabalho apresenta um estudo prático da aplicação do conceito Leak Before Break (LBB), usualmente aplicado em usinas nucleares, em uma tubulação fabricada a partir de aço AISI 316LN soldada com a utilização de eletrodo revestido AISI 316L. O LBB é um critério fundamentado em análises de mecânica da fratura, que considera que um vazamento proveniente de uma trinca, presente em uma tubulação, possa ser detectado por sistemas de detecção de vazamento, antes que esta trinca alcance um tamanho crítico que implique na falha da tubulação. Na tubulação estudada, foram realizados ensaios mecânicos de tração e análises de Ramberg-Osgood, bem como ensaios de tenacidade à fratura para a obtenção da curva de resistência J-R do material. Os ensaios foram realizados considerando o metal base, a solda e a zona termicamente afetada (ZTA), nas temperaturas de operação de uma planta nuclear. Para as propriedades mecânicas encontradas nos ensaios foram realizadas análises de carga limite para se determinar o tamanho da trinca que cause um vazamento detectável e, também, o seu tamanho crítico que cause a falha por colapso plástico. Para o tamanho crítico de trinca encontrado na solda, região que apresentou a menor tenacidade, foram realizadas análises de Integral J e de módulo de rasgamento T, considerando falha por rasgamento dúctil. Os resultados demonstram um comportamento bem definido entre o metal base, a ZTA e a solda, onde o metal base apresenta um comportamento altamente tenaz, a solda um comportamento pouco tenaz e a ZTA apresentou propriedades mecânicas intermediárias entre o metal base e a solda. Utilizando o software PICEP, foram determinadas as curvas de taxa de vazamento versus tamanho de trinca e também o tamanho crítico da trinca, considerando análise por carga limite. Observou-se que, após certo tamanho de trinca, a taxa de vazamento do metal base é muito maior do que para a ZTA e solda, para um mesmo comprimento de trinca. Isso ocorre porque é esperado que a trinca cresça de forma mais arredondada no metal base, devido à sua maior tenacidade. O menor tamanho crítico de trinca foi encontrado para o metal base para trincas circunferenciais. Para as análises de Integral J realizadas na solda, foi demonstrado que a falha por rasgamento dúctil não ocorrerá nas condições consideradas e essa hipótese foi sedimentada pela análise de mecânica da fratura elasto-plástica (MFEL) com o uso do diagrama J/T. Dessa forma, pode-se concluir que a tubulação estudada estaria apta a ser empregada em um circuito primário de um reator que utilizasse o critério de LBB, nas condições de carregamento e geometria consideradas. Adicionalmente, concluiu-se que nessas condições apenas o modo de falha por colapso plástico é esperado. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Memoria (licenciado en ciencias jurídicas y sociales) / La así llamada “experiencia WikiLeaks” nos ha hecho reflexionar acerca de la extensión de la libertad de expresión y de prensa en Estados Unidos, dado que se trata de una nación fundada en ella y su líder durante el transcurso de toda su historia. Además, esa nación devino la principal potencia comunicativa, influyendo y determinando la construcción cultural del occidente post Segunda Guerra, sin olvidar que se trata de la primera potencia económica y militar de La Tierra indiscutiblemente desde el fin de la guerra fría. Con sólo esos hechos se demuestra el interés de al legar antecedentes a la reflexión.

Le tourisme est le fer de lance de l'économie balinaise. Mais, les fruits de cette économie du tourisme ne bénéficient pas à toutes les classes de la société balinaise. Cela est dû, entre autres, au manque à gagner lorsque cette industrie importe par exemple des produits ou des services pour répondre aux besoins des touristes (alimentation pour la restauration par exemple). Le calcul du manque à gagner pour l'économie balinaise n’a jamais été fait auparavant. Pour cela, cette recherche est nécessaire. Les objectifs de la recherche étaient : de calculer le manque à gagner pour l'économie balinaise dans le secteur du logement pour les touristes en micro-économie (niveau industriel) ; d'estimer le manque à gagner pour le tourisme balinais dans le secteur de l'hébergement touristique en macroéconomie (au niveau provincial) ; d'évaluer l'impact de la subvention gouvernementale et la réduction des importations dans l' industrie du tourisme, les opportunités d'emploi et la distribution des revenus ; d'évaluer la perception et le choix des touristes internationaux face aux offres de produits importés et locaux, et aussi d'évaluer l'opinion des touristes sur le constat : est-ce que les dépenses des touristes pendant leur voyage à Bali bénéficient à la société balinaise ? ; et d'évaluer les opinions des gestionnaires des hôtels sur l'utilisation des produits importés et des produit locaux pour la consommation des touristes ; de créer une stratégie afin de minimiser le manque à gagner dans le secteur du tourisme pour l'économie balinaise. La recherche est basée sur les approches quantitatives et qualitatives. Les données primaires ont été recueillies par la méthode du sondage sur quatre destinations touristiques, à savoir : Kuta, Nusa Dua, Sanur et Ubud, auprès d'un échantillon de 79 hôtels selon la méthode de probabilité proportionnelle à la taille qui est divisée en trois échantillons en grappes : hôtels classés 1, 2 et 3 étoiles ; hôtels classés 4 & 5 étoiles et hôtels privés (non-chain) ou appartenant à une chaine hôtelière (chain) ; hôtels non-classés. Nombre de répondants 600 touristes internationaux qui étaient en vacances à ce moment-là. Le calcul du manque à gagner dans l'analyse micro a été mené selon la méthode d'Unluonen et. al. (2011), tandis que l'analyse macro a été faite selon la méthode de Thorbecke (1988) en utilisant l'approche de la matrice de comptabilité sociale (MCS) de la province de Bali de l'année 2010. La perception et le choix des touristes internationaux vis-à-vis des produits importés et locaux ont été analysé selon le logiciel JMP tandis que les stratégies de la minimisation du manque à gagner dans l'économie touristique balinaise ont été créées selon la méthode de l'ISM (interpretive Structural Modelling). [...] Les touristes internationaux choisissent de façon significative les produits locaux et ils sont prêts à dépenser leur argent au bénéfice des populations locales. Les gestionnaires des hôtels sont prêts à utiliser les produits locaux tant que l’offre est suffisante pour remplacer les produits importés. Les stratégies pour minimiser le manque à gagner pour le tourisme à Bali : optimiser les potentiels des produits locaux ; développer l'agriculture et l' élevage, réduire les produits importés pour la consommation des touristes, augmenter l'exportation des produits locaux, augmenter la qualité des produits locaux ainsi que la qualité des ressources humaines locales, renforcer la société locale, inciter le gouvernement à mettre en œuvre une politique de minimisation du manque à gagner dans l'économie touristique, limiter les investissements étrangers dans le secteur du logement touristique, stabiliser les fluctuations des taux de change, augmenter le rôle du Ministère des affaires étrangères, du ministère de l'industrie, du Ministère du commerce ainsi que le rôle du Ministère du tourisme et de l'économie créative afin de réduire ledit manque à gagner. / Tourism has become the leading economic sector in Bali Province of Indonesia. However, the economic impacts of tourism have not been convinced to be full y beneficial for Balinese community. One of the reasons is tourism leakage that occurs when the industry imports both products and services to support tourism industry in Bali. So far, the amount of tourism leakage in Bali has not been calculated yet. Therefore, there is a need to ascertain the current amount of leakage in Bali tourism. The objectives of the study are: (i) to calculate the amount of tourism leakage from accommodation sector in Bali at micro (industrial) level; (ii) to calculate the amount of tourism leakage from accommodation sector in Bali at macro (regional) level; (iii) to evaluate the impacts of government subsidies and import reduction by accommodation sector on tourism leakage, job opportunity and income distribution; (iv) to evaluate the perception and preference of foreign tourists on imported and local products as well as the willingness of foreign tourists to spend their money to benefit of Balinese people; (v) to evaluate the points of view of hotel managers related to imported and local products as well as their willingness in reducing the use of imported product and (vi) to develop strategies in minimizing tourism leakage in accommodation in Bali. Research was designed through quantitative and qualitative approaches. Data was collected by using survey method at four main tourist destinations in Bali, namely: Kuta, Nusa Dua, Sanur and Ubud. There were 79 hotels selected based upon probability proportional to size sampling method which consists of three clusters namely 1,2,3 Star-rated, 4&5 Star-rated either chain and non-chain and Non Star-rated hotels. The number of respondents was 600 foreign tourists were selected as respondents. Calculation of tourism leakage on micro analysis was undertaken by using a method developed by Unluonen, et. al. (2011), meanwhile, on macro analysis was carried out by using a method proposed by Thorbecke ( 1988) which was based on the Social Accounting Matrix (SAM) of Bali 2010. Perception and preference of foreign tourists on imported and local products were analyzed by using JMP program, meanwhile, Interpretative Structural Modelling (ISM) was undertaken to develop strategies. The results show that based on the micro analysis, the highest tourism leakage of accommodation sector in Bali is at 4&5 Star-rated chain hotels (51.0 %), followed by 4&5 Star-rated non-chain hotels (22.7 %), 1,2&3 Star-rated hotels (12.0 %), Non-star rated hotels (8.8 %), and with the average leakage of 18.8 %. Based on macro analysis, tourism leakage of accommodation sector in Bali are as follow: (i) Leakage of Non Star-rated hotels is 2.0 %; (ii) Leakage of 1,2&3 Star-rated hotels is 15.7 %; (iii) Leakage of 4&5 Star-rated non-chain hotels is 7.1 %, (iv) Leakage of 4&5 Star-rated chain hotels is 55.3%; and (v) Average leakage of all types of accommodation is 19.5%. Foreign tourists significantly look for local products and are willing to spend their money for Balinese people. Hotel managers are willing to use local product as long as local products are available to substitute the imported products. Strategies for minimization tourism leakage are optimizing the potential of local products, develop agriculture and livestock; reduce the use of imported products for tourists, improve quality of local products and human resources, empower community, urge government to develop and implement supporting policies in minimizing tourism leakage, establish policy on restriction of foreign investment on accommodation in Bali, improve the role of Ministry of Foreign Affairs, Ministry of Industry, Ministry of Trade and Ministry of Tourism and Creative Economy. 7 Ps of marketing mix on service: product, price, place, promotion, people, process and physical evidence need to be implemented in order to support sustainable tourism in Bali

[ES] La sectorización de las redes ha demostrado ser una metodología estratégica en la reducción de los volúmenes incontrolados fugados, considerado uno de los principales problemas a los que tienen que enfrentarse diariamente los gestores de los sistemas de distribución de agua. Su principal objetivo es facilitar la monitorización de las redes, dividiéndolas en subsistemas, sobre los que se puede realizar un mejor y más fácil control de las anomalías en el consumo y presión. Uno de los inconvenientes que presenta esta técnica recae en su diseño. No existe una solución única, sino que atiende a diversos criterios para realizarlo. De manera generalizada, este diseño se basa en la experiencia del propio diseñador, siguiendo criterios puramente prácticos y con procesos manuales de prueba y error, cuyo grado de dificultad está vinculado al tamaño y complejidad de la propia red. Esta tesis plantea una metodología sistemática para el diseño de la sectorización de una red de distribución de agua, según criterios energéticos, con el fin de facilitar la delimitación de cada uno de los sectores de la red. Como resultado, se obtiene una organización de la red en sectores buscando una optimización energética de la misma, de tal modo que posteriores técnicas de mejora, como es el caso de la gestión de presiones, se vean favorecidas. La sectorización ha resultado ser una técnica eficaz en la búsqueda de fugas. Sin embargo, como supone una pérdida de capacidad hidráulica y una merma en la calidad del agua, esta tesis se cuestiona el planteamiento de una técnica no intrusiva alternativa que logre los mismos resultados. Así, se propone el desarrollo de una metodología que localice las fugas centrada en la interdependencia de todos los elementos y en el empleo de sensores de caudal y presión. El trabajo pone de manifiesto que es posible sectorizar la red de tal manera que se consigan mayores beneficios para la misma. Ahora bien, también es posible el empleo de otras técnicas que no requieran el cierre de tuberías pero que desprendan soluciones similares. El empleo de una técnica u otra dependerá de cada caso, de los objetivos establecidos y de la política de trabajo de cada gestor. / [CA] La sectorització de les xarxes ha demostrat ser una metodologia estratègica en la reducció dels volums incontrolats perduts, considerat un dels principals problemes als quals han d'enfrontar-se diàriament els gestors dels sistemes de distribució d'aigua. El seu principal objectiu és facilitar la monitorització de les xarxes, dividint-les en subsistemes, sobre els quals es pot realitzar un millor i més fàcil control de les anomalies en el consum i pressió. Un dels inconvenients que presenta aquesta tècnica recau en el seu disseny. No existeix una solució única, sinó que atén diversos criteris per a realitzar-ho. De manera generalitzada, aquest disseny es basa en l'experiència del propi dissenyador, seguint criteris purament pràctics i amb processos manuals de prova i error, el grau de dificultat del qual està vinculat a la grandària i complexitat de la pròpia xarxa. Aquesta tesi planteja una metodologia sistemàtica per al disseny de la sectorització d'una xarxa de distribució d'aigua, segons criteris energètics, amb la finalitat de facilitar la delimitació de cadascun dels sectors de la xarxa. Com a resultat, s'obté una organització de la xarxa en sectors buscant una optimització energètica d'aquesta, de tal manera que posteriors tècniques de millora, com és el cas de la gestió de pressions, es vegen afavorides. La sectorització ha resultat ser una tècnica eficaç en la cerca de fuites d'aigua. No obstant això, com suposa una pèrdua de capacitat hidràulica i una disminució en la qualitat de l'aigua, aquesta tesi es qüestiona el plantejament d'una tècnica no intrusiva alternativa que aconseguisca els mateixos resultats. Així, es proposa el desenvolupament d'una metodologia que localitze les fuites d'aigua centrada en la interdependència de tots els elements i en l'ús de sensors de cabal i pressió. El treball posa de manifest que és possible sectoritzar la xarxa de tal manera que s'aconseguisquen majors beneficis per a aquesta. Ara bé, també és possible l'ús d'altres tècniques que no requerisquen el tancament de canonades però que desprenguen solucions similars. L'ús d'una tècnica o una altra dependrà de cada cas, dels objectius establits i de la política de treball de cada gestor. / [EN] The sectorization of networks has proven to be a strategic methodology in the reduction of uncontrolled leakage volumes, considered one of the main problems that water distribution system managers must face on a daily basis. Its main objective is to facilitate the monitoring of the networks, dividing them into subsystems, on which a better and easier control of anomalies in consumption and pressure can be performed. One of the drawbacks of this technique lies in its design. There is no single solution, but it is based on different criteria. In general, this design is based on the designer's own experience, following purely practical criteria and with manual trial and error processes, whose degree of difficulty is linked to the size and complexity of the network itself. This thesis proposes a systematic methodology for the design of the sectorization of a water distribution network, according to energy criteria, in order to facilitate the delimitation of each of the sectors of the network. As a result, an organization of the network in sectors is obtained, looking for an energetic optimization of the same, in such a way that later improvement techniques, such as pressure management, are favoured. Sectorization has proven to be an effective technique in the search for leaks. However, as it implies a loss of hydraulic capacity and a decrease in water quality, this thesis questions the approach of an alternative non-intrusive technique that achieves the same results. Thus, it is proposed the development of a methodology to locate the leaks focused on the interdependence of all the elements and the use of flow and pressure sensors. The present work shows that it is possible to sectorize the network in such a way as to achieve greater benefits for the network. However, it is also possible to use other techniques that do not require pipe closure but provide similar solutions. The use of one technique or another will depend on each case, on the established objectives and on the working policy of each manager. / Salguero Barceló, FJ. (2021). La sectorización basada en criterios energéticos como herramienta para la gestión hídrica de redes de distribución de agua [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/178235 / TESIS

In traditional investment decision making, one tool commonly used is the mean variance model, also known as an expected-value variance (EV) model, which evaluates the anticipated payout of different assets with respect to uncertainty where portfolios with higher risk demand higher expected returns from an individual. This thesis adapts this framework to a cost setting where decision makers are evaluating alternative physical assets that carry lifetime cost uncertainty for maintenance. Specifically, this paper examines homeowner choices for their home plumbing systems in the event of a pinhole leak, a tiny pin-sized hole that forms in copper, drinking-water pipes. These leaks can cause substantial damage and cost homeowners thousands of dollars in repairs. Since pinhole leaks are not related to the age of pipe material, a homeowner is subject to the risk of additional costs if a pinhole leak occurs again despite their repair efforts. The EV cost model in this paper defines two discrete choices for the homeowner in the event of a leak; to apply a simple repair at lower cost and higher future cost uncertainty, or to replace their plumbing with new pipe material, usually made of plastic, at a higher upfront cost but lower likelihood of future expenses. The risk preference of homeowners are demonstrated by their repair strategy selection, as well as the level of cost they incur to reduce uncertainty. Risk neutral individuals will select the repair strategy with the lowest lifetime expected cost and high variance, while risk averse homeowners will prefer to replace their plumbing with higher cost but lower variance. Risk averse individuals are also exposed to indirect costs, which is an additional unobserved cost in the form of a risk premium the homeowner is willing to pay to remove all uncertainty of future pinhole leak expense. Expected costs and variances are also higher for regions in the U.S. that experience elevated leak incident rates, known as hotspots. Using this mean variance cost framework, indirect cost can be quantified for homeowners in hotspot regions and compared to the rest of the U.S. to evaluate the magnitude of pinhole leak risk. The EV cost model estimates risk premiums on pinhole leaks to be $442 for homeowners in hotspots and $305 for those in the rest of the U.S. Finally, this paper examines the impact of pinhole leak cost uncertainty on the U.S. economy. Of an estimated $692 million in annual pinhole leak costs to homeowners, this study estimates a lower bound cost of $54 million per year (7.8% of estimated national annual cost) in risk premium that homeowners would be willing to pay to avoid pinhole leak cost uncertainty. Information in this study on the role of risk in home plumbing decisions and indirect costs would be helpful to policymakers and water utility managers as they deal with infrastructure management decisions. Furthermore, the EV cost methodology established in this paper demonstrates an effective use of mean variance modeling under cost uncertainty. / Master of Science

Pinhole leaks in copper plumbing pipes are a big concern for the homeowners. The problem is spread across the nation and remains a threat to plumbing systems of all ages. Due to the absence of a single acceptable mechanistic theory no preventive measure is available to date. Most of the present mechanistic theories are based on analysis of failed pipe samples however an objective comparison with other pipes that did not fail is seldom made. The variability in hydraulic and water quality parameters has made the problem complex and unquantifiable in terms of plumbing susceptibility to pinhole leaks. The present work determines the spatial and temporal spread of pinhole leaks across United States. The hotspot communities are identified based on repair histories and surveys. An assessment of variability in water quality is presented based on nationwide water quality data. A synthesis of causal factors is presented and a scoring system for copper pitting is developed using goal programming. A probabilistic model is presented to evaluate optimal replacement time for plumbing systems. Methodologies for mechanistic modeling based on corrosion thermodynamics and kinetics are presented. / Master of Science

<p>Det här examensarbetet är baserat på idéer ur ett uppdrag från företaget Saab Aerotech men är ett eget arbete.</p><p>Målet var att undersöka om det finns behov av ett verktyg som statiskt kan detektera dynamiska minneshanteringsproblem, som till exempel minnesläckage, i applikationer skrivna i C/C++. På grund av att minneshanteringsfel i C/C++ länge har varit ett känt problem undersökte vi detta och de befintliga lösningarna till det.</p><p>Vi fann två metoder till lösningar som de flesta verktyg använde sig av; statisk och dynamisk detektering. De flesta verktyg löste problemet genom att dynamiskt detektera minnesläckor och andra brister som till exempel buffer overflows. Ett verktyg löste dock problemet genom att statisk detektera minneshanteringsfel i källkoden för applikationerna. Eftersom alla befintliga lösningar har någon form av ineffektivitet så har vi undersökt möjligheten att utveckla ett mer effektivt verktyg. Vi har kommit fram till att denna möjlighet finns men det kräver enormt mycket tid och arbete att göra ett komplett verktyg som detekterar minneshanteringsfel statiskt.</p><p>Vår prototyp detekterar dynamiska minneshanteringsproblem i källkoden statiskt. Vi har använt oss av hjälpverktygen Flex och Bison för att utveckla vår prototyp av verktyget. Prototypen kan analysera källkod skriven i programspråken C och C++ och klarar att detektera minnesläckage, felaktiga avallokeringar av minne, dangling pointers, samt läsning från och skrivning till ogiltiga minnesområden. På grund av tidsbrist har vi i nuläget inte implementerat något stöd för klasser och objekt i prototypen.</p> / <p>This bachelor’s project is our own project, but it is based on ideas from an assignment from the Saab Aerotech company.</p><p>The goal was to investigate if there is a need for a tool that statically can detect dynamic memory management errors, such as memory leaks, in applications written in C/C++. Since the problem of memory management errors in the C/C++ languages has been known for a long time, we decided to investigate this and the existing solutions.</p><p>We found that most tools used two methods as solutions; static and dynamic detection. Most of these tools solve the problem by dynamically detecting memory leaks and other deficiencies such as buffer overflows. However, one of these tools used static detection of these deficiencies by scanning the source code of the applications. Since all the existing solutions have some kind of inefficiency, we have investigated the possibility to develop a more efficient tool. We concluded that this is possible but it will take a lot of time and effort to implement a complete tool that statically detects memory management errors.</p><p>Our prototype statically detects dynamic memory management problems in the source code. We have used the tools Flex and Bison to develop our prototype of a static detection tool. The prototype analyzes source code written in the programming languages C and C++ and is capable of detecting memory leaks, invalid deallocations of memory, dangling pointers and reading from and writing to invalid memory areas. Currently, due to lack of time, we have not implemented any support for classes and objects in the prototype.</p>

Det här examensarbetet är baserat på idéer ur ett uppdrag från företaget Saab Aerotech men är ett eget arbete. Målet var att undersöka om det finns behov av ett verktyg som statiskt kan detektera dynamiska minneshanteringsproblem, som till exempel minnesläckage, i applikationer skrivna i C/C++. På grund av att minneshanteringsfel i C/C++ länge har varit ett känt problem undersökte vi detta och de befintliga lösningarna till det. Vi fann två metoder till lösningar som de flesta verktyg använde sig av; statisk och dynamisk detektering. De flesta verktyg löste problemet genom att dynamiskt detektera minnesläckor och andra brister som till exempel buffer overflows. Ett verktyg löste dock problemet genom att statisk detektera minneshanteringsfel i källkoden för applikationerna. Eftersom alla befintliga lösningar har någon form av ineffektivitet så har vi undersökt möjligheten att utveckla ett mer effektivt verktyg. Vi har kommit fram till att denna möjlighet finns men det kräver enormt mycket tid och arbete att göra ett komplett verktyg som detekterar minneshanteringsfel statiskt. Vår prototyp detekterar dynamiska minneshanteringsproblem i källkoden statiskt. Vi har använt oss av hjälpverktygen Flex och Bison för att utveckla vår prototyp av verktyget. Prototypen kan analysera källkod skriven i programspråken C och C++ och klarar att detektera minnesläckage, felaktiga avallokeringar av minne, dangling pointers, samt läsning från och skrivning till ogiltiga minnesområden. På grund av tidsbrist har vi i nuläget inte implementerat något stöd för klasser och objekt i prototypen. / This bachelor’s project is our own project, but it is based on ideas from an assignment from the Saab Aerotech company. The goal was to investigate if there is a need for a tool that statically can detect dynamic memory management errors, such as memory leaks, in applications written in C/C++. Since the problem of memory management errors in the C/C++ languages has been known for a long time, we decided to investigate this and the existing solutions. We found that most tools used two methods as solutions; static and dynamic detection. Most of these tools solve the problem by dynamically detecting memory leaks and other deficiencies such as buffer overflows. However, one of these tools used static detection of these deficiencies by scanning the source code of the applications. Since all the existing solutions have some kind of inefficiency, we have investigated the possibility to develop a more efficient tool. We concluded that this is possible but it will take a lot of time and effort to implement a complete tool that statically detects memory management errors. Our prototype statically detects dynamic memory management problems in the source code. We have used the tools Flex and Bison to develop our prototype of a static detection tool. The prototype analyzes source code written in the programming languages C and C++ and is capable of detecting memory leaks, invalid deallocations of memory, dangling pointers and reading from and writing to invalid memory areas. Currently, due to lack of time, we have not implemented any support for classes and objects in the prototype.

<p>Three issues will be elaborated and disussed in the proposed thesis. The first is<br />administration and control of data access rights in networks with XML data, with<br />emphasis on data security. The second is the administration and control of<br />access rights to data in computer networks with RDF data, with emphasis on<br />data privacy. The third is prevention of errors and memory leaks, as well as<br />communication errors, generated by programs written in Sing # language in the<br />presence of exceptions. For all three issues, there will be presented formal<br />models with corresponding type systems and showed the absence of undesired<br />behavior i.e. errors in networks or programs.</p> / <p>У тези су разматрана три проблема. Први је администрација и контрола<br />права приступа података у рачунарској мрежи са XML подацима, са<br />нагласком на безбедости посматраних података. Други је администрација и<br />котрола права приступа подацима у рачунарској мрежи са RDF подацима,<br />са нагласком на приватности посматраних података. Трећи је превенција<br />грешака и цурења меморије, као и грешака у комуникацији генерисаним<br />програмима написаних на језику Sing# у којима су присутни изузеци. За сва<br />три проблема биће предложени формални модели и одговарајући типски<br />системи помоћу којих се показује одсуство неповољних понашања тј.<br />грешака у мрежама односно програмима.</p> / <p>U tezi su razmatrana tri problema. Prvi je administracija i kontrola<br />prava pristupa podataka u računarskoj mreži sa XML podacima, sa<br />naglaskom na bezbedosti posmatranih podataka. Drugi je administracija i<br />kotrola prava pristupa podacima u računarskoj mreži sa RDF podacima,<br />sa naglaskom na privatnosti posmatranih podataka. Treći je prevencija<br />grešaka i curenja memorije, kao i grešaka u komunikaciji generisanim<br />programima napisanih na jeziku Sing# u kojima su prisutni izuzeci. Za sva<br />tri problema biće predloženi formalni modeli i odgovarajući tipski<br />sistemi pomoću kojih se pokazuje odsustvo nepovoljnih ponašanja tj.<br />grešaka u mrežama odnosno programima.</p>