A novel system identification (SI)-based structural health assessment (SHA) procedure has been developed integrating several theoretical and implementation aspects. The procedure assesses health of structures using limited noise-contaminated dynamic responses and without using input excitation information. Since most practical structures are three dimensional (3D), the procedure has been developed for general 3D structures, represented by finite elements (FEs). The procedure identifies defects by tracking the changes in the stiffness of the elements in the FE representation. Once a defective element is identified, defect spot can be identified accurately within the defective element. The procedure is denoted as 3D Generalized Iterative Least-Squares Extended Kalman Filter with Unknown Input (3D GILS-EKF-UI) and implemented in two stages. In Stage 1, based on the available responses, substructure(s) are selected and the 3D GILS-UI procedure is used to generate the unknown input excitation, stiffness parameters of the elements in the substructure, and two Rayleigh damping coefficients. Using information from Stage 1, stiffness parameters for the whole structure are identified using EKF with Weighted Global Iteration (EKF-WGI) in Stage 2. The procedure accurately identified defect-free and defective states of various 3D structures using only analytically generated limited responses. To increase the robustness, 3D GILS-EKF-UI has been extended to develop an integrated structural health assessment strategy, denoted as Iterative Least-Squares Extended Kalman Filter with Unknown Input and Advanced Digital Integration Technique (ILS-EKF-UI-ADIT). The procedure has been implemented in three stages. In Stage 1, an advanced digital integration technique (ADIT) is implemented for post-processing of noise-contaminated acceleration time-histories, addressing all major challenges of digital integration. It also overcomes non-convergence issue in Stage 2 that arises due to phase-shift and amplitude errors. In Stage 2, substructure(s) are identified using the least-squares procedure. In Stage 3, stiffness parameters for the whole structure are identified using the EKF-WGI procedure. ILS-EKF-UI-ADIT has been verified in presence of relatively large noise in the acceleration time-histories, measured at small part(s) of defect-free and defective structures, without using excitation information. The SHA procedure is robust and has the potential to be applied for the health assessment, maintenance, retrofitting, and life extension of existing structural systems.

No description available.

No description available.

No description available.

Syfte: Syftet med studien är att bidra med en ökad förståelse för hur kvalitetsförbättringsarbete används för att eliminera brister och fel inom byggbranschen. Metod:  Studien utfördes genom kvalitativ metod med hermeneutiskt synsätt samt tolkning. Fallstudien omfattar fyra intervjurespondenter varav en pilotstudie samt 42 enkäter till samtliga tjänstemän och medarbetare med ledaransvar på olika nivåer inom kvalitetsförbättringsarbetet. Insamlad data bearbetades med hjälp av tematisk analys för att sedan analyseras och tolkas. Slutligen drogs slutsatser från resultat och analysmaterialet. Resultat & Slutsats: Med hjälp av litteraturgenomgången och resultatet av det undersökta fallföretaget har studien kommit fram till att det är utmanande och svårt men inte omöjligt att implementera kvalitetsförbättringsmetoder och tekniker i byggbranschen utifrån de unika förutsättningar som råder i byggbranschen. Det råder samsyn bland de tillfrågade gällande vad de upplever är de vanligast förekommande kvalitetsbrister och fel vid slutbesiktning. Några av de enkla och kortsiktiga steg som framkommit i studien som kan ha positiva och långsiktiga effekter är främst att se fel och brister som ett resultat av alla delar i processen, fokusera på kvalitet lika mycket under hela processen, att involvera utförandenivån även i planering och målsättning, att i större utsträckning driva kvalitetsförbättringsarbetet i team på arbetsplatserna, att träna och utbilda samtliga ledare för kvalitetsförbättringsarbete och kanske även medarbetarna för ökad delaktighet och kunskap, att utveckla systematik för faktabaserad kunskapsåterföring och att ge tillräckligt uppmärksamhet och erkännande till medarbetare för prestationer kanske genom att låta dem själva få redovisa och utvärdera sitt eget och varandras arbete.

Mit wellenlängenabhängigen Messungen der Oberflächenphotospannung (Surface Photovoltage, SPV) lässt sich die Diffusionslänge von Ladungsträgern im Volumen von Siliziumproben messen. Das Ziel der Arbeit war es, mit Hilfe temperatur- und injektionsabhängiger Messungen der Diffusionslänge die Natur rekombinationsaktiver Defekte in kristallinem Silizium zu untersuchen. Im Rahmen der Arbeit wurde eine zu diesem Zwecke geeignete Messanlage sowie die nötigen Mess- und Auswerteprozeduren entwickelt. Die Möglichkeiten und Grenzen der aufgebauten Anlage wurden durch Messungen an gezielt mit Eisen, Kupfer oder Chrom verunreinigten mono- und multikristallinen Siliziumproben bewertet. Es zeigt sich, dass die SPV-Methode in einem jeweils begrenzten Temperatur- und Injektionsbereich bei Vorhandensein dominanter Defekte zur Defekt-Spektroskopie einsetzbar ist. Eine Anwendung fand das Verfahren an industriell relevantem, aufbereitetem metallurgischen Silizium (umg-Si).

In the adult brain, the thalamocortical tract conveys sensory information from the external environment to the cortex. The cortex analyzes and integrates this information and sends neural responses back to the thalamus through the corticothalamic tract. To reach their final target both thalamocortical and corticothalamic axons have to cover long distances during embryogenesis, changing direction several times and passing through different brain territories. The ventral telencephalon plays a major role in the early development of these tracts. At least three main axon guidance mechanisms act in the ventral telencephalon. First, two different populations of pioneer neurons in the lateral ganglionic eminence (LGE) (LGE pioneer neurons) and medial ganglionic eminence (MGE) (MGE pioneer neurons) provide scaffolds which allow growing corticothalamic and thalamocortical axons to cross the pallium sub pallium boundary (PSPB) and the diencephalic telencephalic boundary (DTB), respectively. Second, the ventral telencephalon forms a permissive corridor for thalamic axons by tangential migration of Isl1 and Ebf1 expressing cells from the LGE into the MGE. Finally, thalamortical and corticothalamic axons guide each other once they have met in the ventral telencephalon (“handshake hypothesis”). The Gli3 transcription factor has been shown to be essential for normal early embryonic regionalization of the mammalian forebrain, although roles of Gli3 in later aspects of forebrain development, like the formation of axonal connections, have not been investigated previously. Here, I present the analysis of axonal tract development in the forebrain of the Gli3 hypomorphic mutant mouse Polydactyly Nagoja (Pdn). These animals lack the major axonal commissures of the forebrain: the corpus callosum, the hippocampal commissure, the anterior commissure and the fimbria. In addition, DiI injections and neurofilament (NF) staining showed defects in the formation of the corticothalamic and thalamocortical tracts. Although the Pdn/Pdn cortex forms early coticofugal neurons and their axons, these axons do not penetrate the LGE and instead run along the PSPB. Later in development, although a thick bundle of Pdn/Pdn cortical axons is still observed to project along the PSPB, some Pdn/Pdn cortical axons eventually enter the ventral telencephalon navigating along several abnormal routes until they reach thalamic regions. In contrast, Pdn/Pdn thalamic axons penetrate into the ventral telencephalon at early stages of thalamic tract development. However, rostrally they deviate from their normal trajectory, leaving the internal capsule prematurely and only few of them reach the developing cortex. Caudally, an ectopic Pdn/Pdn dorsal thalamic axon tract projects ventrally in the ventral telencephalon not entering the internal capsule at all. These defects are still observed in newborn Pdn/Pdn mutant mice. Next, I investigated the developmental mechanisms causing these pathfindings defects. No obvious defects are present in Pdn/Pdn cortical laminae formation and in the patterning of the Pdn/Pdn dorsal thalamus. In addition, Pdn/Pdn thalamocortical axons are able to respond to ventral telencephalic guidance cues when transplanted into wild type brain sections. However, these axonal pathfinding defects correlate with patterning defects of the Pdn/Pdn LGE. This region is partially ventralized and displays a reduction in the number of postmitotic neurons in the mantle zone due to an elongated cell cycle length of LGE progenitor cells. Finally, Pdn/Pdn mutant display an upregulation of Shh expression and Shh signalling in the ventral telencephalon. Interestingly, these patterning defects lead to the absence of DiI back-labelled LGE pioneer neurons, which correlates with the failure of corticothalamic axons to penetrate the ventral telencephalon. In addition, ventral telencephalic thalamocortical guidance mistakes happen at the same time of abnormal formation of the corridor cells. Taken together these data reveal a novel role for Gli3 in the formation of ventral telencephalic intermediate cues important for the development of the thalamocortical and corticothalamic connections. Indeed, Pdn animals are the first known mutants with defective development of the LGE pioneer neurons, and their study provides a link between early patterning defects and axon pathfinding in the developing telencephalon.

Context. Software defect prediction aims to reduce the large costs involved with faults in a software system. A wide range of traditional software metrics have been evaluated as potential defect indicators. These traditional metrics are derived from the source code or from the software development process. Studies have shown that no metric clearly out performs another and identifying defect-prone code using traditional metrics has reached a performance ceiling. Less traditional metrics have been studied, with these metrics being derived from the natural language of the source code. These newer, less traditional and finer grained metrics have shown promise within defect prediction. Aims. The aim of this dissertation is to study the relationship between short Java constructs and the faultiness of source code. To study this relationship this dissertation introduces the concept of a Java sequence and Java code snippet. Sequences are created by using the Java abstract syntax tree. The ordering of the nodes within the abstract syntax tree creates the sequences, while small sub sequences of this sequence are the code snippets. The dissertation tries to find a relationship between the code snippets and faulty and non-faulty code. This dissertation also looks at the evolution of the code snippets as a system matures, to discover whether code snippets significantly associated with faulty code change over time. Methods. To achieve the aims of the dissertation, two main techniques have been developed; finding defective code and extracting Java sequences and code snippets. Finding defective code has been split into two areas - finding the defect fix and defect insertion points. To find the defect fix points an implementation of the bug-linking algorithm has been developed, called S + e . Two algorithms were developed to extract the sequences and the code snippets. The code snippets are analysed using the binomial test to find which ones are significantly associated with faulty and non-faulty code. These techniques have been performed on five different Java datasets; ArgoUML, AspectJ and three releases of Eclipse.JDT.core Results. There are significant associations between some code snippets and faulty code. Frequently occurring fault-prone code snippets include those associated with identifiers, method calls and variables. There are some code snippets significantly associated with faults that are always in faulty code. There are 201 code snippets that are snippets significantly associated with faults across all five of the systems. The technique is unable to find any significant associations between code snippets and non-faulty code. The relationship between code snippets and faults seems to change as the system evolves with more snippets becoming fault-prone as Eclipse.JDT.core evolved over the three releases analysed. Conclusions. This dissertation has introduced the concept of code snippets into software engineering and defect prediction. The use of code snippets offers a promising approach to identifying potentially defective code. Unlike previous approaches, code snippets are based on a comprehensive analysis of low level code features and potentially allow the full set of code defects to be identified. Initial research into the relationship between code snippets and faults has shown that some code constructs or features are significantly related to software faults. The significant associations between code snippets and faults has provided additional empirical evidence to some already researched bad constructs within defect prediction. The code snippets have shown that some constructs significantly associated with faults are located in all five systems, and although this set is small finding any defect indicators that transfer successfully from one system to another is rare.

The direct chill (DC) casting technique to produce billets for extrusion and ingots for rollingwas developed in the 1930s. The principle, which is still valid, is a two-stage cooling with a primary cooling at a mould surface followed by water spraying directly on the surface. Improvements of this technique have mainly focused on changes to the primary cooling, where a water-cooled metal mould has been replaced by different techniques to minimize cooling at this stage. The drive for development comes from the extrusion industry, which can increase the productivity and quality of extruded profiles by improving the billet surface appearance and structure. Hot top casting supported by airflow against the casting surface during the primary cooling is currently the standard procedure to achieve acceptable billet surfaces. The goal is to minimize the depth of the surface segregation zone, which is the governing factor for the appearance of different phases in the surface region. Billet surface quality is evaluated by quantifying surface appearance, segregation zone thickness, and  occurrence of large Mg2Si and β-particles near the surface. The β-Al5FeSi intermetallic phase and coarse Mg2Si particles have negative effects on extrudability and workability of 6xxx Al alloys billets. To achieve extruded products with a high surface quality the as-cast billets are  heat-treated before extrusion. During heat treatment the undesired intermetallic particles, i.e., β-AlFeSi platelets are transformed to rounded α-Al(FeMn)Si intermetallic phases. In this  research the formation of the surface segregation for smooth defect-free surfaces in both as-cast and homogenized billets was studied. In addition, the surfaces with defects such as wavy, spot and vertical drag defects were investigated and possible mechanisms for initiation of those defects were explained. Moreover, for a better understanding of the homogenization process in-situ studies of the heat treatment of 6082, 6005, 6060 and 6063 Al alloys were carried out by using a transmission electron microscope (TEM). Based on the observations, an explanation of the probable mechanisms taking place during transformation from β-to α-phase was presented. / <p>Vid tidpunkten för disputationen var följande delarbeten opublicerade: delarbete 5 manuskript, delarbete 6 inskickat och delarbete 7 inskickat.</p><p>At the time of the doctoral defence the following papers were unpublished: paper 5 manuscript, paper 6 submitted, paper 7 submitted.</p>

En fastighetsaffär är en av de allra största och viktigaste investeringarna som kan ske i en människas liv. Det är därför viktigt att aktuell lagstiftning följs när dessa affärer genomförs. Efter att en fastighet har sålts är det inte ovanligt att det uppstår tvister och oklarheter kring vem som ansvarar för så kallade dolda fel i fastigheten. Dolda fel är något som kan uppmärksammas efter köpet. Enligt jordabalken gäller i normalfallet att säljaren ansvarar för dessa fel i 10 år från det att köpet gjordes. Säljaren kan undvika detta ansvar genom att friskriva sig från fel i fastigheten. Enligt jordabalken är sådana friskrivningar ogiltiga i de fall då en näringsidkare säljer en fastighet till en konsument. Enligt vår tolkning av lagen och dess förarbeten gäller detta även när kommuner säljer fastigheter till privatpersoner. I denna studie ska det undersökas hur väl kommunerna är medvetna om att denna begränsning i lagen finns och hur de såväl i praktiken som i teorin förhåller sig till den, vid fastighetsförsäljningar till privatpersoner. För att söka svar på frågorna ska en kombination av en juridisk och en kvalitativ metod använts. Totalt ska det under studiens gång granskas 46 stycken kontrakt från 10 olika kommuner. Studien baseras på en granskning av 46 stycken kontrakt, varav 52 % visade sig vara ogiltiga enligt JB 4 kap. 19 d. Vidare visade granskningen att majoriteten av dessa är utformade på ett av tre alternativa sätt, där samtliga innehöll minst en friskrivning från fel och brister i fastigheten. Studien visar även att stor okunskap råder i kommunerna angående hur regeln ska tolkas och hur denna typ av friskrivning därför bör hanteras i de kommunala kontrakten. Dessutom visar studien på att de ansvariga i kommunerna inte heller verkar vara medvetna om att samma syfte som de vill uppnå genom en friskrivning kan åstadkommas genom en grundlig förklarande beskrivning av köpeobjektet. / Buying a property is one of the biggest and most important investments in a person´s life. When this kind of purchase is being performed it´s important that the Swedish legislation is being considered and followed correctly by both parties when writing the contract. After a property is sold it's not unusual that some disputes and uncertainties rises about who´s responsible for the so called "hidden defects" on the property, which can be found after the purchase has become final. According to Swedish law the seller is responsible for these defects for the following 10 years after the purchase is completed. However there is one way for the seller to avoid this kind of responsibility - by using a disclaimer from these hidden defects. When a trader is selling a property to a consumer, this kind of disclaimers, according to jordabalken (JB) 4 cap. 19 d §, is invalid. According to what the writers can interpret by reading the text of law and the legislative history, JB 4 cap. 19 d § also should be applied in those cases where a municipality is selling a property to a private individual. The purpose of this study is to map the municipalities awareness of the existence of the law and how they consider that the law should be handled when selling a property to a private individual. To seek the answers to these questions a combination of a juridical and a qualitative method have been used. During the study a total of 46 contracts from 10 different municipalities have been examined. The study came across a total of 46 disclaimers, which a percantage of 52 % according to JB 4 cap 19 d § considers as invalid. The majority of these disclaimers was proved to be designed as one of three alternative ways, where every one of them contained some kind of disclaimer from hidden defects and flaws in the property. The study proves that there is big ignorance and lack of knowledge at the municipalities about how the law in JB 4 cap. 19 d § should be interpreted and how this kind of disclaimer therefore should be treated in the contracts. Also, the study shows that the municipalities doesn't seem to be aware that the same purpose that they want to achieve by using the disclaimer, can be accomplished by a detailed description of the property.