Heterogeneous Change Point Inference

We propose HSMUCE (heterogeneous simultaneous multiscale change-point estimator) for the detection of multiple change-points of the signal in a heterogeneous gaussian regression model. A piecewise constant function is estimated by minimizing the number of change-points over the acceptance region of a multiscale test which locally adapts to changes in the variance. The multiscale test is a combination of local likelihood ratio tests which are properly calibrated by scale dependent critical values in order to keep a global nominal level alpha, even for finite samples. We show that HSMUCE controls the error of over- and underestimation of the number of change-points. To this end, new deviation bounds for F-type statistics are derived. Moreover, we obtain confidence sets for the whole signal. All results are non-asymptotic and uniform over a large class of heterogeneous change-point models. HSMUCE is fast to compute, achieves the optimal detection rate and estimates the number of change-points at almost optimal accuracy for vanishing signals, while still being robust. We compare HSMUCE with several state of the art methods in simulations and analyse current recordings of a transmembrane protein in the bacterial outer membrane with pronounced heterogeneity for its states. An R-package is available online

An Investigation in Applying Image Retrieval Techniques to X-Ray Engineering Pictures

Using image retrieval techniques in analysing Non-destructive testing reults is a new challenge in both computing science and engineering applications. Objective of this research is to develop an image retrieval system to analyse X-ray images for welding industry. The content based image retrieval has been used in this investigation, particularly in feature vector paradigm and similarity as well as detailed analysis towards single defects. It is found that X-ray images can be digitally analysed qualitatively and quantitatively easily. It concludes that the use of existing CBIR techniques can provide a platform to quickly develop new image analysis tools

Fully-Automatic Multiresolution Idealization for Filtered Ion Channel Recordings: Flickering Event Detection

We propose a new model-free segmentation method, JULES, which combines recent statistical multiresolution techniques with local deconvolution for idealization of ion channel recordings. The multiresolution criterion takes into account scales down to the sampling rate enabling the detection of flickering events, i.e., events on small temporal scales, even below the filter frequency. For such small scales the deconvolution step allows for a precise determination of dwell times and, in particular, of amplitude levels, a task which is not possible with common thresholding methods. This is confirmed theoretically and in a comprehensive simulation study. In addition, JULES can be applied as a preprocessing method for a refined hidden Markov analysis. Our new methodolodgy allows us to show that gramicidin A flickering events have the same amplitude as the slow gating events. JULES is available as an R function jules in the package clampSeg

Random Attractors for Stochastic Partly Dissipative Systems

We prove the existence of a global random attractor for a certain class of stochastic partly dissipative systems. These systems consist of a partial (PDE) and an ordinary differential equation (ODE), where both equations are coupled and perturbed by additive white noise. The deterministic counterpart of such systems and their long-time behaviour have already been considered but there is no theory that deals with the stochastic version of partly dissipative systems in their full generality. We also provide several examples for the application of the theory.Comment: 29 page

Design and Synthesis of Nickel N-Heterocyclic Carbene Catalyst Systems and Their Application in the Cross-Coupling of Silyloxyarenes

The invention of transition-metal catalyzed cross-coupling reactions has fundamentally changed how chemists approach the synthesis of small molecules. Moreover, the ability to perform reactions catalytically while employing Earth abundant first row transition-metals has had positive impacts regarding sustainability. In addition to environmental considerations, first row transition-metals, like nickel, have been found to possess reactivity that is complementary to metals like palladium, which has implications for how the metal performs in the various elementary steps of catalytic processes. These insights have arisen from the study, design, and development of nickel catalyst systems, which have propelled the invention of catalytic strategies for the formation of a wide array of C‒C and C‒heteroatom bond forming reactions. The nature of reaction development and catalyst design are intimately related as achieving the development of novel bond forming reactions relies upon innovative advances that reduce the limitations associated with existing catalyst systems to provide enhanced performance, or to make the catalysts, themselves, more accessible. An account of these efforts in the context of C‒O bond functionalization and air-stable, discrete nickel(0) (Ni(0)) n-heterocyclic carbene (NHC) catalysts are described, herein. Chapter 1 is largely oriented towards the utility of phenol derivatives as electrophilic coupling partners with low-reactivity C‒O bonds being of main interest. The challenges regarding the activation of these low-reactivity C‒O bonds is discussed, as well as current strategies to overcome their inherently low-reactivity. Although low-reactivity C‒O bonds are challenging to activate, their functionalization is of import as possessing electrophilic coupling partners that range in reactivity enables highly selective sequential couplings, resulting from leveraging the orthogonal reactivity of each electrophile. Chapter 2 chronicles the utility of aryl boronic acids in organic synthesis, with particular attention paid to their role in cross-coupling reactions. The synthesis of these compounds spanning from traditional approaches to modern techniques, which includes the state of the art in the borylation of low-reactivity C‒O bonds. The limitations of these strategies are covered and the development of a borylation of silyloxyarenes is described along with synthetic demonstrations that highlight the ability of silyloxyarenes to be used orthogonally to other electrophiles. Chapter 3 entails the advantages of catalysis, and the transition metal catalysts we rely upon to mediate these processes, with special attention to nickel, have evolved. For the purposes of this dissertation, nickel catalysts have been categorized as 1) Ni(II) salts, 2) discrete Ni(II) pre-catalysts, 3) Ni(0) pre-catalysts, 4) air-stable Ni(0) pre-catalysts, and 5) discrete air-stable Ni(0) pre-catalysts. The advantages and disadvantages, activation strategies, and synthesis of each category are described in detail. Preliminary work regarding progress towards the synthesis of an air-stable, discrete Ni(0) NHC complex from nickel (II) (Ni(II)) precursors and NHC salts is described.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169764/1/pein_1.pd

Biochemical diversity of bacterial isolates from paddy soils of peninsular Malaysia

In this study, the diversity of bacterial isolates from paddy soil located in several rice growing areas of Peninsular Malaysia was evaluated. Phenotypic and physiological characteristics of the isolates were recorded to categorize and identify the bacteria. Ten strains of bacteria were recovered from six different locations (Alor Bakat, Kg. Seligi, Bachok, Kelantan; Sekinchan, Selangor; Kobah, Kedah; and Sg. Batu Pahat, Perlis). The spread-plate technique on nutrient agar at pH 7.0 was used to isolate and purify all the strains. The characteristic of the bacteria strains were determined using the Gram staining, motility test, as well as the shape and size of the single colony on solid media. From the various tests conducted, nine isolates were identified as Gram-positive rods, and only one was Gram-negative cocci. Further biochemical tests were carried out to determine the ability of these bacteria strains to hydrolyze starch, casein and gelatine, ferment carbohydrate (glucose, lactose and sucrose), enzyme production (catalase and oxidase), MR-VP tests and growth under anaerobic condition; the elevated NaCl was also examined. On the basis of these tests and the biochemical characteristics, nine of the strains belonged to the same genus, Bacillus, with three potentially different species. Meanwhile, only one strain showed the characteristics related to Proteus mirabilis. This study also showed that the dominant bacteria genera are generally limited, despite the contrasting geographical location and soil characteristics in which the strains were isolated

Heterogeneous Idealization of Ion Channel Recordings -- Open Channel Noise

We propose a new model-free segmentation method for idealizing ion channel recordings. This method is designed to deal with heterogeneity of measurement errors. This in particular applies to open channel noise which, in general, is particularly difficult to cope with for model-free approaches. Our methodology is able to deal with lowpass filtered data which provides a further computational challenge. To this end we propose a multiresolution testing approach, combined with local deconvolution to resolve the lowpass filter. Simulations and statistical theory confirm that the proposed idealization recovers the underlying signal very accurately at presence of heterogeneous noise, even when events are shorter than the filter length. The method is compared to existing approaches in computer experiments and on real data. We find that it is the only one which allows to identify openings of the PorB porine at two different temporal scales. An implementation is available as an R package

Agile i Skatteetaten – en oversettelsesteoretisk analyse av smidig utvikling i Skatteetaten

Denne masteroppgaven presenterer og forklarer en organisasjonsidé for softwareutvikling, Agile, og hvordan denne ideen er opptatt og anvendt i Skatteetaten. Oppgaven gjør rede for hvordan Agile passer inn i det overordnede teoretiske rammeverket for utvikling og overføring av ideer mellom organisasjoner, og analyserer Skatteetatens bruk av Agile ut i fra et translasjonsteoretisk perspektiv med fokus på hvordan ideen blir oversatt og endret når den introduseres i en organisasjon. Basert på en gjennomgang av tidligere forskningsartikler om Agile argumenterer oppgaven for at Agile kan forstås som en organisasjonsidé slik dette begrepet brukes i de organisasjonsteoretiske tradisjonene oppgaven bygger på. På bakgrunn av intervjuer med ansatte i Skatteetaten og utdrag fra etatens skriftlige rutiner konkluderer analysen med at Agile har vært gjenstand for flere stadier av oversettelse i møte med Skatteetaten, både sentralt og høyt oppe i organisasjonshierakiet og på lavere, lokale nivåer. Oversettelsen har både involvert kopiering av metoder og ideer og modifisering hvor ideene tilpasses organisasjonens virke og rammer. Analysen peker på at Agile er en forholdsvis oversettelsesvennlig organisasjonsidé, og at de største vanskelighetene med å inkorporere ideen i Skatteetaten er spenningsforholdet mellom ideens fokus på endringsevne og autonomi og etatens mindre fleksible overordnede politiske styring

Numerical model for dynamic installation of large diameter monopiles

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