Um die Zuverlässigkeit von intelligenten Stromverteilerleisten zu überprüfen, wird eine Methode entwickelt, die es ermöglicht, weitestgehend automatisierte und herstellerunabhängige Messergebnisse aufzunehmen, zu vergleichen und zu bewerten. Die Betrachtung der Stromverteilerleisten erfolgt hierbei als Blackbox, welche durch einen möglichst vollumfänglichen Satz an Eigenschaften beschrieben wird. Der zur Messung notwendige Testplan wird aus dieser Beschreibung der Eigenschaften automatisch generiert und kann dann getrennt im Labor ausgeführt werden. Dabei wird eine durchgehende Dokumentation des Messablaufs und der Umgebungsbedingungen sichergestellt. Im Nachgang ist eine Analyse der Messergebnisse sowie eine teilautomatisierte Protokollerstellung möglich.

Flextronics Design i Linköping, som ingår i den stora amerikanskägda Flextronics- koncernen, är en industrialiseringsenhet på mobiltelefonsidan. Det innebär att verksamheten kretsar kring att ta fram test- och monteringsprocesser, samt tillhörande utrustning, som sedan implementeras hos högvolymsfabrikerna belägna i olika låg-kostnads-länder. På mobiltelefonerna finns, beroende på modell, ett antal detaljer som pressas fast, antingen för hand, med en manuell press, eller med hjälp av en pneumatisk press. Den sistnämnda pressmetoden används när det rör sig om lite längre presstider på detaljen, från ett par sekunder och uppåt. Idag finns det två modeller som drivs med tryckluft och som pressar med olika kraftintervall beroende på vilket lufttryck som tillförs till systemet. Det har visat sig att det finns ett behov hos företaget att ta fram en ny konstruktion som pressar med ett lägre kraftintervall än de befintliga modellerna kan erbjuda. Det är önskvärt att reducera tillverkningskostnaden jämfört med tidigare modeller. Framförallt är en ny lösning på xy-bordet önskvärd då den står för en stor del av den totala kostnaden. För att tryckbilden, och därmed resultatet, ska bli så bra som möjligt är det också viktigt att konstruktionen går att kalibrera i x- och y-led, samt att även felaktigheter i planheten går att justera. Under konstruktionsarbetet har olika tekniska lösningar och koncept tagits fram som utvärderats. Den slutliga konstruktionen består av en tryckluftscylinder som är dimensionerad för att trycka med de krafter som är specificerade. Den rörliga delen av cylindern förs ner och pressar samman detaljen och telefonen som är placerade i en fixtur. Den är i sin tur fixerad i ett justerbart xy-bord som består av två aluminiumplattor med urfrästa spår. Inställningen av tryckbilden i x- och y-led sker med hjälp av styrpinnar. Eventuella skillnader i planheten verifieras redan vid monteringen av pressen, och justeras genom skimsning. Tillverkningskostnaden för den nya modellen har reducerats med 30 % jämfört med de tidigare pressarna. Konceptlösningen på det nya xy-bordet innebär en kostnadsminskning med 50 % mot det befintliga bordet.

This thesis introduces a new optimization algorithm for simulation-based design of systems with multi-modal, nonlinear, black box objective functions. The algorithm extends the recently introduced adaptive multi-modal optimization by incorporating surrogate modeling features similar to response surface methods (RSM). The resulting optimization algorithm has reduced computational intensity and is therefore well-suited for optimization of expensive black box objective functions. The algorithm relies on an adaptive and multi-resolution mesh to obtain an initial estimation of the objective function surface. Local surrogate models are then constructed to represent the objective function and to generate additional trial points in the vicinity of local minima discovered. The steps of mesh refinement and surrogate modeling continue until convergence criteria are met. An important property of this algorithm is that it produces progressively accurate surrogate models around the local minima; these models can be used for post-optimization studies such as sensitivity and tolerance analyses with minimal computational effort. This algorithm is suitable for optimal design of complex engineering systems and enhances the design cycle by enabling computationally affordable uncertainty analysis. The mathematical basis of the algorithm is explained in detail. The thesis also demonstrates the effectiveness of the algorithm using comparative optimization of several multi-modal objective functions. It also shows several practical applications of the algorithm in the design of complex power and power-electronic systems.

The inversion method for generating non-uniform random variates has some advantages compared to other generation methods, since it monotonically transforms uniform random numbers into non-uniform random variates. Hence it is the method of choice in the simulation literature. However, except for some simple cases where the inverse of the cumulative distribution function is a simple function we need numerical methods. Often inversion by ``brute force" is used, applying either very slow iterative methods or linear interpolation of the CDF and huge tables. But then the user has to accept unnecessarily large errors or excessive memory requirements, that slow down the algorithm. In this paper we demonstrate that with Hermite interpolation of the inverse CDF we can obtain very small error bounds close to machine precision. Using our adaptive interval splitting method this accuracy is reached with moderately sized tables that allow for a fast and simple generation procedure. The algorithms described in this paper have been implemented in ANSI C in a library called UNURAN which is available via anonymous ftp. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing

This thesis introduces a new optimization algorithm for simulation-based design of systems with multi-modal, nonlinear, black box objective functions. The algorithm extends the recently introduced adaptive multi-modal optimization by incorporating surrogate modeling features similar to response surface methods (RSM). The resulting optimization algorithm has reduced computational intensity and is therefore well-suited for optimization of expensive black box objective functions. The algorithm relies on an adaptive and multi-resolution mesh to obtain an initial estimation of the objective function surface. Local surrogate models are then constructed to represent the objective function and to generate additional trial points in the vicinity of local minima discovered. The steps of mesh refinement and surrogate modeling continue until convergence criteria are met. An important property of this algorithm is that it produces progressively accurate surrogate models around the local minima; these models can be used for post-optimization studies such as sensitivity and tolerance analyses with minimal computational effort. This algorithm is suitable for optimal design of complex engineering systems and enhances the design cycle by enabling computationally affordable uncertainty analysis. The mathematical basis of the algorithm is explained in detail. The thesis also demonstrates the effectiveness of the algorithm using comparative optimization of several multi-modal objective functions. It also shows several practical applications of the algorithm in the design of complex power and power-electronic systems.

A new algorithm for sampling from largely abitrary monotone, unbounded densities is presented. The user has to provide a program to evaluate the density and its derivative and the location of the pole. Then the setup of the new algorithm constructs different hat functions for the pole region and for the tail region, respectively. For the pole region a new method is developed that uses a transformed density rejection hat function of the inverse density. As the order of the pole is calculated in the setup, conditions that guarantee the correctness of the constructed hat functions are provided. Numerical experiments indicate that the new algorithm works correctly and moderately fast for many different unbounded densities. (c) ACM, (2007). This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. (author's abstract) / Series: Research Report Series / Department of Statistics and Mathematics

[Abstract] This thesis is divided into two parts, both containing algorithms for dealing with matrices and matrix groups. Part I is concerned with individual matrices over an arbitrary field. Our algorithms make use of a sequence called the rank profile which is related to the linear dependence relations between the columns of a matrix. First we look at LSP decompositions of matrices as defined by Ibarra et al. in 1982. This decomposition is related to, and a little more general than, the LUP decomposition. The algorithm given by Ibarra et al. to compute an LSP decomposition was only defined for m?n matrices where m ≤ n and is claimed to have the same asymptotic cost as matrix multiplication. We prove that their cost analysis overlooked some aspects of the computation and present a new version of the algorithm which finds both an LSP decomposition and the rank profile of any matrix. The cost of our algorithm is the same as that claimed by Ibarra et al. when m ≤ n and has a similar cost when m > n. One of the steps in the Ibarra et al. algorithm is not completely explicit, so that any one of several choices can be made. Our algorithm is designed so that the particular choice made at this point allows for the simultaneous calculation of the rank profile. Next we study algorithms to find the characteristic polynomial of a square matrix. The current fastest algorithm to find the characteristic polynomial of a square matrix was developed by Keller-Gehrig in 1985. We present a new, simpler version of this algorithm with the same cost which makes the algorithm?s reliance on the rank profile explicit. In Part II we present generalised sifting, a scheme for creating Monte Carlo black box constructive group recognition algorithms. Generalised sifting is designed to facilitate computation in a known group, specifically re-writing arbitrary elements as words or straight-line programs in a standard generating set. It can also be used to create membership tests in black-box groups. Generalised sifting was inspired by the subgroup sifting techniques originally introduced by Sims in 1970 but uses a chain of subsets rather than subgroups. We break the problem down into a sequence of separately analysed and proven steps which sift down into each subset in turn ... All of the algorithms in Parts I and II are given with a theoretical proof and (where appropriate) complexity analysis. The LSP decomposition, characteristic polynomial and generalised sifting algorithms have all been implemented and tested in the computer algebra package GAP.

The relationship people have to electronic devices relys on their passive acceptance rather than an understanding of their functioning – often leaving the users alientated and helpless as their products break. Which qualities do electronic artifacts need to embody in order to be repairable? As opposed to a black-box, the metaphor of a white-box can describe this repairable ideal: A white-box is meant to be opened and allows easy access to all inner parts. It is designed to communicate functions and connections and aids the user in understanding. Therefore, a white-box is designed to allow the consumer to act. How «open» can household electronics be?

abstract: Web applications are an incredibly important aspect of our modern lives. Organizations and developers use automated vulnerability analysis tools, also known as scanners, to automatically find vulnerabilities in their web applications during development. Scanners have traditionally fallen into two types of approaches: black-box and white-box. In the black-box approaches, the scanner does not have access to the source code of the web application whereas a white-box approach has access to the source code. Today’s state-of-the-art black-box vulnerability scanners employ various methods to fuzz and detect vulnerabilities in a web application. However, these scanners attempt to fuzz the web application with a number of known payloads and to try to trigger a vulnerability. This technique is simple but does not understand the web application that it is testing. This thesis, presents a new approach to vulnerability analysis. The vulnerability analysis module presented uses a novel approach of Inductive Reverse Engineering (IRE) to understand and model the web application. IRE first attempts to understand the behavior of the web application by giving certain number of input/output pairs to the web application. Then, the IRE module hypothesizes a set of programs (in a limited language specific to web applications, called AWL) that satisfy the input/output pairs. These hypotheses takes the form of a directed acyclic graph (DAG). AWL vulnerability analysis module can then attempt to detect vulnerabilities in this DAG. Further, it generates the payload based on the DAG, and therefore this payload will be a precise payload to trigger the potential vulnerability (based on our understanding of the program). It then tests this potential vulnerability using the generated payload on the actual web application, and creates a verification procedure to see if the potential vulnerability is actually vulnerable, based on the web application’s response. / Dissertation/Thesis / Masters Thesis Computer Science 2017

O trabalho aqui apresentado observa a possibilidade de liberdade criativa através da interface musical na obra de arte bricolada com meios eletrônicos: a artemídia. Segundo o filósofo Vilém Flusser, perdemos a capacidade de criar e desenvolver o sentimento livre, uma vez introduzida a tecnologia em nossas vidas. Essas caixas pretas, as quais não sabermos ao certo o seu conteúdo, nos obriga a executar sempre a mesma rotina maquínica, nos aprisionando. Com o desenvolvimento da interface musical na artemídia essa realidade muda e, graças a ela, temos a possibilidade e a liberdade criativa restituída. / The work presented here looks at the possibility of creative freedom through the music interface in the art work mixed with electronic media: the artmedia. According to philosopher Vilém Flusser, we lost the ability to create and develop the free feeling once introduced the technology in our lives. These \"black boxes\", which we do not know sure for your inside, require us to always perform the same machined routine, imprisoning us. With the development of musical interface in artmedia that reality changes, and thanks to it, we have the opportunity and creative freedom restored.