Moving from a project-based to a product-based organization comes with its own challenges, which goes for most organizations when one business model is changed to another. These changes lead to uncertainties in the work for the engineers, where lead time increases and time for the projects. This master thesis aimed to evaluate the uncertainties' characteristics and set standardizations in the work process to optimize the workflow and reduce engineering hours spent per project. The goals set for this thesis formulated three research questions: RQ1: What characterizes a reduction of engineering uncertainties through product-based structures?  RQ2: How can current layout modules be converted into standardized product-based structures? RQ3: How can standardized layout modules ensure the reduction of engineering uncertainties throughout the product-development process? By examining a case company’s journey through this transition through a quantitative methodology, three cases that each follow the product development process were conducted to answer the three research questions. The results for this thesis indicated that the implementation of standards reduced lead time and overall inconsistency, thus contributing to a more efficient modelling environment for the engineers and consistent implementation of an adaptable model for PDM integration. Implementing a design for assembly methodology proved to be a successful choice in reducing the assembly time for the engineers. An evaluation of the results indicates that only 34% of the engineering hours currently spent on conducting customer-based layout routings for the case company would be necessary when utilizing the standardized modules. / Att övergå från ett projektbaserat till ett produktbaserat bolag kan leda till vissa motgångar då övergången innebär förändringar i struktur och produktion. Dessa motgångar uppstår för en majoritet av bolag som implementerar denna övergång, där förändringar inom organisationen leder till ett antal osäkerheter i arbetet för ingenjörer som ökad ledtid och tidsåtgång för projekt. Målet med denna studie är att utvärdera vilka osäkerheter som uppstår och att standardisera arbetsprocessen för att optimera arbetsflödet och reducera tidsåtgång för ingenjörer per projekt. Målen för denna studie har genererat tre forskningsfrågor: FF1: Vad karaktäriserar en reducering av ingenjörsosäkerheter genom produktbaserade strukturer? FF2: Hur kan nuvarande layout moduler konverteras till standardiserade produktbaserade strukturer? FF3: Hur kan standardiserade layout moduler säkerställa reduktion av ingenjörsosäkerheter genom produktutvecklingsprocessen? Genom att undersöka ett fallföretags resa genom övergångsprocessen med en kvantitativ metodologi, genererades tre fall som följde produktutvecklingsprocessen för att utförligt svara på forskningsfrågorna. Resultaten för denna studie indikerar att implementeringen av standarder reducerar ledtid och övergripande inkonsekvens, vilket därmed bidrar till en mer effektiv konstruktionsmiljö för ingenjörerna, samt en mer konsistent implementering av en tillämpbar modell för PDM integrering. Implementeringen av design för sammanställnings metodologi visade sig vara ett lyckat val i att reducera sammanställningstid för ingenjörerna. En utvärdering av resultaten visar att endast 34% av den tid det tar för fallföretaget i dagsläget att utföra en fullständig ”layout routing” är nödvändig när standardiserade moduler tillämpas.

The Quality of Service (QoS) routing approach is gaining an increasing interest in the Internet community due to the new emerging Internet applications such as real-time multimedia applications. These applications require better levels of quality of services than those supported by best effort networks. Therefore providing such services is crucial to many real time and multimedia applications which have strict quality of service requirements regarding bandwidth and timeliness of delivery. QoS routing is a major component in any QoS architecture and thus has been studied extensively in the literature. Scalability is considered one of the major issues in designing efficient QoS routing algorithms due to the high cost of QoS routing both in terms of computational effort and communication overhead. Localized quality of service routing is a promising approach to overcome the scalability problem of the conventional quality of service routing approach. The localized quality of service approach eliminates the communication overhead because it does not need the global network state information. The main aim of this thesis is to contribute towards the localised routing area by proposing and developing some new models and algorithms. Toward this goal we make the following major contributions. First, a scalable and efficient QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated. Second, we have developed a path selection technique that can be used with existing localized QoS routing algorithms to enhance their scalability and performance. Third, a scalable and efficient hierarchical QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated.

Problem of traffic routing in autonomous system is under consideration. The solution of this problem would stabilize the operation of the network in case of accidents and high loads. A method for generating analogy of routing table based on the modification of the actual table. Two test sites were constructed for testing and finding a method of stabilization of an autonomous system routing information. The result of the introduction of an autonomous system route reflectors showed that route reflectors increases the stability of the system routing within an autonomous system and reduces the lack of communication between the nodes. / В работе актуализируется проблема маршрутизации трафика внутри автономной системы. Решение этой задачи позволит стабилизировать работу сети при авариях и высоких нагрузках. Разработан метод генерирования аналога таблицы маршрутизации на основе модификации реальной таблицы. Построены две тестовые площадки для тестирования и поиска метода стабилизации маршрутной информации автономной системы. Результат внедрения в автономную систему отражателей маршрутов показал, что они увеличивают стабильность системы маршрутизации трафика и уменьшают время отсутствия связи между узлами

Numerous mobile applications have the potential to collect and share userspecific information on top of the essential data handling. This is made possible through poor application design and its improper implementation. The lack of security and privacy in an application is of main concern since the spread of sensitive and personal information can cause both physical and emotional harm, if it is being shared with unauthorized people. This thesis investigates how to confidentially transfer user information in such a way that the user remains anonymous and untraceable in a mobile application. In order to achieve that, the user will first authenticate itself to a third party, which provides the user with certificates or random generated tokens. The user can then use this as its communication credentials towards the server, which will be made through the Tor network. Further, when the connection is established, the WiFi details are sent periodically to the server without the user initiating the action. The results show that it is possible to establish connection, both with random tokens and certificates. The random tokens took less time to generate compared to the certificate, however the certificate took less time to verify, which balances off the whole performance of the system. Moreover, the results show that the implementation of Tor is working since it is possible for the system to hide the real IP address, and provide a random IP address instead. However, the communication is slower when Tor is used which is the cost for achieving anonymity and improving the privacy of the user. Conclusively, this thesis proves that combining proper implementation and good application design improves the security in the application thereby protecting the users’  privacy. / Många mobilapplikationer har möjlighet att samla in och dela användarspecifik information, utöver den väsentliga datahanteringen. Det här problemet möjliggörs genom dålig applikationsdesign och felaktig implementering. Bristen på säkerhet och integritet i en applikation är därför kritisk, eftersom spridning av känslig och personlig information kan orsaka både fysisk och emotionell skada, om den delas med obehöriga personer. Denna avhandling undersöker hur man konfidentiellt kan överföra användarinformation på ett sätt som tillåter användaren av mobilapplikationen att förbli både anonym och icke spårbar. För att uppnå detta kommer användaren först att behöva autentisera sig till en tredje part, vilket förser användaren med slumpmässigt genererade tecken eller med ett certifikat. Användaren kan sedan använda dessa till att kommunicera med servern, vilket kommer att göras över ett Tor-nätverk. Slutligen när anslutningen upprättats, kommer WiFi-detaljerna att skickas över periodvis till servern, detta sker automatiskt utan att användaren initierar överföringen. Resultatet visar att det är möjligt att skapa en anslutning både med ett certifikat eller med slumpmässiga tecken. Att generera de slumpmässiga tecknen tog mindre tid jämfört med certifikaten, däremot tog certifikaten mindre tid att verifiera än tecknen. Detta resulterade i att de båda metoderna hade en jämn prestanda om man ser över hela systemet. Resultatet visar vidare att det implementeringen av Tor fungerar då det är möjligt för systemet att dölja den verkliga IPadressen och att istället tillhandahålla en slumpmässig IP-adress. Kommunikationen genom Tor gör dock systemet långsammare, vilket är kostnaden för att förbättra användarens integritet och uppnå anonymitet. Sammanfattningsvis visar denna avhandling att genom att kombinera korrekt implementering och bra applikationsdesign kan man förbättra säkerheten i applikationen och därmed skydda användarnas integritet.

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No / This paper presents a new partitioning strategy with the objective of increasing scalability by reducing computational effort of routing in networks. The original network is partitioned into blocks (subnetworks) so that there is a bi-directional link between any two blocks. When there is a connection request between a pair of nodes, if the nodes are in the same block, we only use the small single block to derive routings. Otherwise we combine the two blocks where the two nodes locate and in this way the whole network will never be used. The strategy is generic in that it can be used in any underlying routing algorithms in the network layer and can be applied to any networks with fixed topology such as fixed wired subnetworks of the Internet. The performance of this strategy has been investigated by building a simulator in Java and a comparison with existing stochastic partitioning techniques is shown to give superior performance in terms of trade-off in blocking probability (the probability of failure to find a path between source and destination satisfying QoS constraints) and reduction of computational effort.

This thesis dissertation addresses the problem of providing video streaming services over mobile wireless ad hoc networks. This sort of network represents a hostile environment for this kind of realtime data transmission to the extent that obtaining a good quality of viewer experience is challenging and still under study. Besides the research point of view, providing high-quality multimedia services is decisive for the practical usability and feasibility of wireless ad hoc networks so that service providers can broaden the range of services offered. So far, mobile wireless ad hoc networks have been used to provide network connection among users who could not have connectivity otherwise. However, quality expectations and requirements have been increased notably, fostered by the advent of real-time multimedia applications over mobile devices. Due to the considerable processing and bandwidth constraints underlying these types of devices, coupled with their ability to move freely, it becomes a difficult task to achieve an acceptable quality of service throughout the entire video transmission. Thus, the contribution of this thesis work is twofold. On the one hand, the main problems and limitations that may be encountered and should be faced when deploying real-time services over mobile wireless ad hoc networks are analyzed and discussed. Bandwidth constraints and node mobility are portrayed as the major causes that prevent good quality of service and smooth video playback. On the other hand, following then the aim of improving video streaming quality, this thesis proposes practical solutions that involve diverse routing and cross-layer techniques. One of the proposed approaches focuses on hierarchical routing. Hierarchical arrangement of network nodes may reduce packet interference as well as offer a structured architecture that reduces control traffic overhead. Particularly, the proposed hierarchical routing protocol aims at providing scalability when the number of nodes grows, while maintaining complexity as low as possible. The resulting reduction in packet losses and video playback interruptions finally enhances the quality of received video streams. Furthermore, on the basis that the nodes in an ad hoc network are willing to perform routing tasks, every node could become essential for the proper network operation and routing performance. In tune with this philosophy, a new cross-layer mechanism for recovering lost packets is proposed. By overhearing packets over the wireless shared medium, any node in the surrounding area of the destination endpoint can altruistically retransmit those video packets that have not been correctly received at destination. Moreover, due to the video awareness and frame prioritization algorithm considered in this proposal, it becomes very convenient for real-time video streaming services. The results show that the presented mechanism succeeds in improving video quality and user experience, especially when packet losses are caused due to the mobility of the destination node. / Arce Vila, P. (2014). Hierarchical routing and cross-layer mechanisms for improving video streaming quality of service over mobile wireless ad hoc networks [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/36538

Background Efficient underwater operations with autonomous underwater vehicles (AUVs) relying on several factors for a mission to be successful, such as operation time, distance covered, and waiting times. Today’s methods and processes for AUVs often struggle with inefficiencies and lack of route optimization. These challenges can result in increased operational costs and suboptimal performance. Minimizing operation time and utilizing route planning algorithms enables adaptation to operational challenges, potentially resulting in cost savings. Objectives This thesis aims to identify an efficient and practical solutions that will improve the operations for AUVs and the objective is to optimize the diving process through suboptimal routing algorithms in a predefined scenario. The study addresses one primary question to achive the aim. The question were: How can routing algorithms be implemented to improve the efficiency and reduce the operation time of Autonomous Underwater Vehicles? Methods The method describes three heuristic algorithms for optimizing the operations of AUVs. The first algorithm, the nearest neighbor heuristic (NNH) aims to minimize the distance an AUV needs to travel to recover and deploy ocean bottom nodes (OBN) within a cluster. The second algorithm, inspired by railway traffic, tries to prevent overlaps and minimizing the waiting times at the depot station. The third algorithm is highlighted as a local optimization algorithm that prioritizes the shortest waiting time over the nearest distance, adapting dynamically to available depot stations. Results The results in this thesis are derived from numerous simulations from different scenarios. The relationship between operations time and waiting time for different scenarios was obtained. The first algorithm proved to work for this type of situation. The second algorithm demonstrated its ability to yield superior solutions, albeit at the cost of being time-consuming due to a high number of iterations. The third algorithm was examined under conditions with and without delays. Even with delays, the algorithm consistently manages disturbances effectively. Conclusions While achieving an exact optimal solution remains challenging due to complexity, the research showed promising improvements in the endurance of the AUVs through the algorithms. The first algorithm was effective in minimizing the distance the AUVs traveled by selecting the most efficient path from numerous potential solutions. The second algorithm was slow due to a large number iterations, but the algorithm was able to find a solution where the operation and waiting time of the AUV could be reduced. The third algorithm was faster, but generally resulted in longer operation times. Also, increasing the number of AUVs resulted in shorter operation times but led to longer waiting times at the depot station, particularly in scenarios that became saturated with too many AUVs. / Bakgrund Undervattensoperationer med autonoma undervattensfarkoster (AUV:er) är beroende av flera faktorer för framgångsrika uppdrag, såsom driftstid, avstånd och väntetider. Dagens metoder och processer för AUV:er har ofta problem med ineffektivitet och bristande optimering av rutter. Dessa utmaningar kan leda till ökade driftkostnader och suboptimal prestanda. Genom att minimera operationstiden och använda ruttplaneringsalgoritmer möjliggörs anpassning till operativa utmaningar, vilket potentiellt kan resultera i kostnadsbesparingar. Syfte Detta examensarbete syftar till att utveckla effektiva och praktiska lösningar för att förbättra systemets prestanda och målet är att optimera rutterna genom suboptimala algoritmer i ett fördefinierat scenario. Arbetet behandlar en primärfråga för att uppnå målet. Frågan var: Hur kan ruttalgoritmer implementeras för att förbättra effektiviteten och minska drifttiden för autonoma undervattensfarkoster? Metod Metoden beskriver tre heuristiska algoritmer för att optimera driften förAUV:er. Den första algoritmen, närmaste granne heuristiken (NNH), syftar till attminimera avståndet en AUV behöver resa för att hämta och placera ut havsbottennoder (OBN) inom en kluster. Den andra algoritmen, inspirerad av tågtrafiken, syftar till att endast en AUV befinner sig vid depåstationen åt gången för att förhindra konflikter och minimera väntetider. Den tredje algoritmen är en lokal optimeringsalgoritm som prioriterar kortaste väntetiden över närmaste avstånd och anpassar sig dynamiskt till tillgängliga depåstationer. Resultat Resultaten i denna uppsats baseras på ett flertal simuleringar med olika scenarier. Förhållandet mellan drifttid och väntetid för olika scenarier erhölls. Den första algoritmen visade sig fungera bra för denna typ av situation. Den andra algoritmen visade sin förmåga att ge bättre lösningar, trots att den var tidskrävande pågrund av ett högt antal iterationer. Den tredje algoritmen undersöktes under förhållanden med och utan förseningar. Trots förseningar lyckades algoritmen konsekvent hantera störningar effektivt. Slutsats Trots komplexiteten med att tillhandahålla en exakt optimal lösning, visade arbetet förbättringar i AUV:ers uthållighet genom olika algoritmer. Den första algoritmen var effektiv för att minimera det avstånd som AUV:er färdades genom att välja en optimal väg bland många potentiella lösningar. Den andra algoritmen var långsam på grund av många iterationer, men algoritmen kunde hitta en lösning där AUV:ens drift- och väntetid kunde minskas. Den tredje algoritmen var snabbare men resulterade i längre drifttider. Vidare resulterade ökningen av antalet AUV:er i en minskning av drifttider men ökade väntetider, särskilt i scenarier som blev mättade med för många AUV:er.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Traditional data acquisition systems have relied on physical connections between data sources and data receivers to handle the routing of acquired data streams. However, these systems grow exponentially in complexity as the number of data sources and receivers increases. New techniques are needed to address the ever increasing complexity of data acquisition. Furthermore, more advanced mechanisms are needed that move past the limitations of traditional data models that connect each data source to exactly one data receiver. This paper presents a software framework for the playback of multiplexed data acquired from a network acquisition system. This framework uses multicast technologies to connect data sources with multiple data receivers. The network acquisition system is briefly introduced before the software framework is discussed. Both the challenges and advantages involved with creating such a system are presented. Finally, this framework is applied to an aviation telemetry example.