Influence of binary mask estimation errors on robust speaker identification

Missing-data strategies have been developed to improve the noise-robustness of automatic speech recognition systems in adverse acoustic conditions. This is achieved by classifying time-frequency (T-F) units into reliable and unreliable components, as indicated by a so-called binary mask. Different approaches have been proposed to handle unreliable feature components, each with distinct advantages. The direct masking (DM) approach attenuates unreliable T-F units in the spectral domain, which allows the extraction of conventionally used mel-frequency cepstral coefficients (MFCCs). Instead of attenuating unreliable components in the feature extraction front-end, full marginalization (FM) discards unreliable feature components in the classification back-end. Finally, bounded marginalization (BM) can be used to combine the evidence from both reliable and unreliable feature components during classification. Since each of these approaches utilizes the knowledge about reliable and unreliable feature components in a different way, they will respond differently to estimation errors in the binary mask. The goal of this study was to identify the most effective strategy to exploit knowledge about reliable and unreliable feature components in the context of automatic speaker identification (SID). A systematic evaluation under ideal and non-ideal conditions demonstrated that the robustness to errors in the binary mask varied substantially across the different missing-data strategies. Moreover, full and bounded marginalization showed complementary performances in stationary and non-stationary background noises and were subsequently combined using a simple score fusion. This approach consistently outperformed individual SID systems in all considered experimental conditions

Instability of spatial patterns and its ambiguous impact on species diversity

Self-arrangement of individuals into spatial patterns often accompanies and promotes species diversity in ecological systems. Here, we investigate pattern formation arising from cyclic dominance of three species, operating near a bifurcation point. In its vicinity, an Eckhaus instability occurs, leading to convectively unstable "blurred" patterns. At the bifurcation point, stochastic effects dominate and induce counterintuitive effects on diversity: Large patterns, emerging for medium values of individuals' mobility, lead to rapid species extinction, while small patterns (low mobility) promote diversity, and high mobilities render spatial structures irrelevant. We provide a quantitative analysis of these phenomena, employing a complex Ginzburg-Landau equation.Comment: 4 pages, 3 figures and supplementary information. To appear in Phys. Rev. Lett

Artificial Intelligence for Lameness Detection in Horses-A Preliminary Study

Simple Summary In the expanding field of artificial intelligence, deep learning and smart-device-technology, a diagnostic software tool was developed, which can help distinguish between lame and sound horses and locate the affected limb. As lameness influences the welfare of horses and is often difficult to detect, this tool can help owners and veterinarians in the process of evaluation. The technology is based on pose estimation, which is already used in human and veterinary science to study movement of limbs or bodies without the need to fix any devices onto the object of interest. In this study, 22 horses with unilateral fore- or hindlimb lameness and a control group of eight sound horses were analysed with the program. Based on the results of the program, it was possible to differentiate between horses with fore- and hindlimb lameness and sound horses. Difficult light settings, such as direct sunlight or darkness, or very even-coloured coats, complicate the precise placement of reference points. The analysis and detection with software-generated movement trajectories using pose estimation is very promising but requires further development. Lameness in horses is a long-known issue influencing the welfare, as well as the use, of a horse. Nevertheless, the detection and classification of lameness mainly occurs on a subjective basis by the owner and the veterinarian. The aim of this study was the development of a lameness detection system based on pose estimation, which permits non-invasive and easily applicable gait analysis. The use of 58 reference points on easily detectable anatomical landmarks offers various possibilities for gait evaluation using a simple setup. For this study, three groups of horses were used: one training group, one analysis group of fore and hindlimb lame horses and a control group of sound horses. The first group was used to train the network;afterwards, horses with and without lameness were evaluated. The results show that forelimb lameness can be detected by visualising the trajectories of the reference points on the head and both forelimbs. In hindlimb lameness, the stifle showed promising results as a reference point, whereas the tuber coxae were deemed unsuitable as a reference point. The study presents a feasible application of pose estimation for lameness detection, but further development using a larger dataset is essential

Reassessment of the Norwegian wool value chain using circular economic principles

In this thesis we have followed Norwegian wool from extraction and throughout the current value chain. This includes a farmer, wool stations, and wool refineries. In addition, we have sourced empirical data from key stakeholders. This consists of a representative from Norilia and a researcher that has contributed greatly to the theme of Norwegian wool. Through an exploratory research design, we have been able to enter a field of study without prior knowledge. This has also allowed for incremental implementation of knowledge towards later empirical sourcing. The theory in the thesis concerns wool as a material, focusing mainly on Norwegian low-category wool, but also includes global perspectives. It also provides theory on circular economy concerning definitions, circular economy perspectives in value chains and the applicability of circular economy. We have applied the 4Rs of circular economy to reassess the value chain, as a means to uncover potential alternatives to the current system. We believe that circular economy principles can contribute to increased value creation for low-category wool. This entails innovative measures that prevent waste, secure valuable resources inherent in the wool and plan for future use. The thesis contains examples on alternative uses and processing techniques. These examples explain how conventional methods can be challenged in new ways with improved results. Rather than an addition to the theory of circular economy, this is an attempt to use aspects of circular economy to add to the field that concerns Norwegian low-category wool. The thesis attempts to shine a new light on an established system and challenge its ways. The degree of transferability to other fields is therefore present. We have built upon the work, but not limited to, by Kirchherr on the circular economy, and the work that has been conducted in KRUS and VerdifULL. The process has been an eye opener for us as wool has such a broad range of applicabilities. The same can be said for the circular economy principles. We hope that this thesis is of interest and gives you, the reader, fruitful takeaways

​​Reassessment of the Norwegian wool value chain using circular economic principles

Summary In this thesis we have followed Norwegian wool from extraction and throughout the current value chain. This includes a farmer, wool stations, and wool refineries. In addition, we have sourced empirical data from key stakeholders. This consists of a representative from Norilia and a researcher that has contributed greatly to the theme of Norwegian wool. Through an exploratory research design, we have been able to enter a field of study without prior knowledge. This has also allowed for incremental implementation of knowledge towards later empirical sourcing. The theory in the thesis concerns wool as a material, focusing mainly on Norwegian low-category wool, but also includes global perspectives. It also provides theory on circular economy concerning definitions, circular economy perspectives in value chains and the applicability of circular economy. We have applied the 4Rs of circular economy to reassess the value chain, as a means to uncover potential alternatives to the current system. We believe that circular economy principles can contribute to increased value creation for low-category wool. This entails innovative measures that prevent waste, secure valuable resources inherent in the wool and plan for future use. The thesis contains examples on alternative uses and processing techniques. These examples explain how conventional methods can be challenged in new ways with improved results. Rather than an addition to the theory of circular economy, this is an attempt to use aspects of circular economy to add to the field that concerns Norwegian low-category wool. The thesis attempts to shine a new light on an established system and challenge its ways. The degree of transferability to other fields is therefore present. We have built upon the work, but not limited to, by Kirchherr on the circular economy, and the work that has been conducted in KRUS and VerdifULL. The process has been an eye opener for us as wool has such a broad range of applicabilities. The same can be said for the circular economy principles. We hope that this thesis is of interest and gives you, the reader, fruitful takeaways. Sammendrag I denne avhandlingen har vi fulgt materialet norsk ull fra ekstraksjon og gjennom den nåværende verdikjeden. Vi har vært i kontakt med en bonde, ullstasjoner og ullraffinerier. I tillegg har vi generert data fra nøkkelinformanter: en representant fra Norilia, og en forsker som har bidratt til vitenskap om norsk ull i stor grad. Gjennom et eksplorativt forskningsdesign, har vi gått inn i et felt uten forkunnskap. Dette har muliggjort en inkrementell implementasjon av kunnskap gjennom den empiriske utviklingen. Teorigrunnlaget for avhandlingen handler om ull som materiale, med særlig fokus på norsk ull av lavere kategorier, men vi inkluderer også et globalt perspektiv. Det inneholder også teori om sirkulærøkonomi, dets definisjoner, sirkulære verdikjeder, og praktisk anvendelse. Vi har brukt de fire R-ene i sirkulærøkonomi som rammeverk i vår gjennomgang av ullas verdikjede, for å avdekke potensielle alternativer til det nåværende systemet. Vi mener at sirkulærøkonomiske prinsipper kan bidra til økt verdiskapning for lav-kategorisk ull. Dette innbefatter innovative tiltak som reduserer avfall, sikrer verdifulle ressurser i ulla, og en bedre planlegging for fremtidig bruk. Avhandlingen inneholder eksempler på alternativ bruk av lav-kategori ull og ulike prosesseringsteknikker. Disse eksemplene forklarer hvordan konvensjonelle metoder kan bli utfordret på nye måter, og gi bedre resultater. Heller enn å være et tilskudd til teorien om sirkulærøkonomi, er dette et forsøk på benytte aspekter innen sirkulærøkonomi for å bidra til feltet som handler om norsk ull av lavere kategorier. Avhandlingen forsøker å kaste nytt lys på et etablert system, og utfordre det. Graden av overførbarhet til andre felt er til stede. Vi har bygget på arbeidet til, men ikke begrenset til, Kirchherr på sirkulærøkonomi, samt arbeidet som er gjort i prosjektene KRUS og VerdifUll. Prosessen har vært en øyeåpner når det gjelder kartlegging av de mange anvendelsesmulighetene for ull. Det samme kan hevdes når det gjelder å bruke sirkulærøkonomiske prinsipper for å gjennomgå etablerte verdikjeder. Vi håper denne avhandlingen er interessant, og gir deg, leseren, nyttig læring

On Batching Variable Size Inputs for Training End-to-End Speech Enhancement Systems

The performance of neural network-based speech enhancement systems is primarily influenced by the model architecture, whereas training times and computational resource utilization are primarily affected by training parameters such as the batch size. Since noisy and reverberant speech mixtures can have different duration, a batching strategy is required to handle variable size inputs during training, in particular for state-of-the-art end-to-end systems. Such strategies usually strive a compromise between zero-padding and data randomization, and can be combined with a dynamic batch size for a more consistent amount of data in each batch. However, the effect of these practices on resource utilization and more importantly network performance is not well documented. This paper is an empirical study of the effect of different batching strategies and batch sizes on the training statistics and speech enhancement performance of a Conv-TasNet, evaluated in both matched and mismatched conditions. We find that using a small batch size during training improves performance in both conditions for all batching strategies. Moreover, using sorted or bucket batching with a dynamic batch size allows for reduced training time and GPU memory usage while achieving similar performance compared to random batching with a fixed batch size

Zum Einfluss von Gunkgo biloba-Extrakt (EGb761) und seiner Komponenten auf die Expression von Transthyretin im Maushirn: eine immunhistochemische Studie

Mit über 35 Millionen Betroffenen weltweit ist die Alzheimersche Erkrankung (AD) die häufigste Demenzerkrankung in westlichen Industrieländern. Durch stetig steigende Prävalenz, gekoppelt mit der zunehmenden Lebenserwartung, erfährt die AD eine immer schwerwiegendere ökonomische und soziale Bedeutung, zumal es bis heute keine wirksame Therapie gibt. Entsprechend ist für mögliche Therapieansätze dieser Erkrankung ein genaues Verständnis der neuropathologischen Mechanismen unerlässlich. So werden neben Therapien, die die cholinerge Hypofunktion und damit auch die zwei weiteren Hauptmerkmale (Amyloid-Plaques und neurofibrilläre Tangles) der AD positiv beeinflussen, auch viele weitere Therapieansätze geprüft. So weiß man, dass einige Substanzen die Expression verschiedener Proteine im Gehirn beeinflussen können, die eine mögliche Rolle bei der Pathogenese der AD spielen. Vor allem untersucht die vorliegende Arbeit, ob eine chronische Behandlung mit dem Ginkgo biloba-Extrakt EGb761 eine veränderte Expression der Proteine Transthyretin (TTR), Prolaktin, Gesamt-Tau und Wachstumshormon (GH) in Hirnen von Mäusen bewirkt. Diese Marker zeigten sich in Mikroarray-Vorversuchen in Hirnmaterial von mit Ginkgo biloba behandelten Mäusen auf Ebene der Genexpression verändert. Veränderungen werden in verschiedenen Fütterungsgruppen dargestellt und diskutiert. Hierzu wird das Methodenspektrum der Immunhistochemie sowie der computergestützten Bildanalyse mittels Densitometrie genutzt. EGb761 sowie im Besonderen dessen Flavonoid-Fraktion bewirkten – im Vergleich zur Kontrollgruppe – eine signifikant erhöhte Immunreaktivität des Proteins Transthyretin in der hippokampalen Formation, während die Terpenoid-Fraktion keine Wirkung auslöste. Die übrigen Marker erschienen unbeeinflusst. Die Ergebnisse werden sowohl im Zusammenhang mit der aktuellen Literatur zu AD als auch mit verschiedenen, vermeintlich neuroprotektiven Proteinen diskutiert