A Simple Modularity Measure for Search Spaces based on Information Theory

Within the context of Artificial Life the question about the role of modularity has turned out to be crucial, especially with regard to the problem of evolvability. In order to be able to observe the development of modular structure, appropriate modularity measures are important. We introduce a continuous measure based on information theory which can characterize the coupling among subsystems in a search problem. In order to illustrate the concepts developed, they are applied to a very simple and intuitive set of combinatorial problems similar to scenarios used in the seminal work by Simon (1969). It is shown that this measure is closely related to the classification of search problems in terms of Separability, Non-Decomposability and Modular Interdependency as introduced in (Watson and Pollack, 2005)

Numerical Study of Lymph Mechanics

Methods taken from engineering and computer science were applied to the lymphatic system. Starting with a 3D analysis of a single subject-specific lymphatic valve. A mechanism was presented to explain previous experimental results showing the effect of trans-mural pressure on the pressure required to close lymphatic valves. The impor-tance of wall motion in future FSI studies of lymphatic valve dynamics were identified. Previous approaches to lumped modelling of the lymphatic system were considered and modifications were proposed. A less-idealised valve model, incorporating trans-mural dependent bias, was proposed as well as a method of allowing self-organised contrac-tion through a stretch-dependent frequency of contraction. A network of the superficial lymphatics of the upper-limb was reconstructed from an anatomical sketch. The net-work was used in conjunction with the lumped model to produce a 421 vessel lymphatic model consisting of 17,706 lymphangions. Several issues which impede large network scale modelling of the lymphatic system are identified. A simplified patient-specific biphasic model of lymphoedema was proposed and used to develop a novel shape-based metric for lymphoedema. A statistically significant relationship between the metric and the presence of lymphoedema was found

Radial Basis Function Differential Quadrature Method for the Numerical Solution of Partial Differential Equations

In the numerical solution of partial differential equations (PDEs), there is a need for solving large scale problems. The Radial Basis Function Differential Quadrature (RBFDQ) method and local RBF-DQ method are applied for the solutions of boundary value problems in annular domains governed by the Poisson equation, inhomogeneous biharmonic equation, and the inhomogeneous Cauchy-Navier equations of elasticity. By choosing the collocation points properly, linear systems can be obtained so that the coefficient matrices have block circulant structures. The resulting systems can be efficiently solved using matrix decomposition algorithms (MDAs) and fast Fourier transforms (FFTs). For the local RBFDQ method, the MDAs used are modified to account for the sparsity of the arrays involved in the discretization. An adjusted Fasshauer estimate is used to obtain a good shape parameter value in the applied radial basis functions (RBFs) for the global RBF-DQ method while the leave-one-out cross validation (LOOCV) algorithm is employed for the local RBF-DQ method using a sample of local influence domains. A modification of the kdtree algorithm is used to select the nearest centers for each local domain. In several numerical experiments, it is shown that the proposed algorithms are capable of solving large scale problems while maintaining high accuracy

On the profitability of technical trading

The sole use of price and related summary statistics in a technical trading strategy is an anathema to weak-form market efficiency. In practice, however, traders actively use technical analysis to make investment decisions which makes this an important, but often neglected, area for study. This thesis includes four empirical chapters, which provide important evidence on the profitability of technical trading. The results from the detailed analysis undertaken in this thesis have broad relevance to both academics and those in the investment community. Existing research has been predominantly confined to evaluating basic technical trading rules, such as moving averages. Crucially, this ignores chart patterns. Widely employed by practitioners, such patterns form a vital part of technical analysis. As the most important price pattern, the head and shoulders pattern is subjected to detailed and thorough examination in this thesis. A significant contribution is made by evaluating formations recognised and used by traders, in sharp contrast to limited existing studies. Furthermore, a new method is developed to establish how quickly profits from a head and shoulders strategy decay, which has important implications for traders. Existing research has identified both reversal and relative strength effects in financial asset returns. A key separator between these two findings is the formation and holding time over which portfolios of winners and losers are evaluated. Motivated by this, a very large sample of ultra high-frequency data is used to investigate intraday momentum and reversal effects. As well as being an important contribution to research in this field, the results are, once again, of relevance to practitioners. The need for further research into technical analysis is clearly demonstrated by point and figure charting. Whilst traders have made consistent use of the technique for around a century, the amount of existing research is extremely small. Point and figure has attractive data filtering properties, clear trading rules and is particularly suited to intraday technical analysis. Again, using a very large sample of high-frequency data, a detailed evaluation of the profitability of a point and figure trading strategy is undertaken

Philosophy in Early Medieval Ireland: Nature, Hierachy and Inspiration

Where we find medieval distinctions between philosophy and theology, the term ‘philosophy’ describes the mode and degree the soul’s participation in the gracious revelation of God’s wisdom apart from – though ideally in cooperation with – the further means of grace which are manifest through the Church alone. This thesis explores what philosophy, thus defined, means in an early Irish context, and does this through an exploration of the way that nature is conceptualised in contrast to the realities and capacities taken to be manifest in the Church. Chapter 1 discusses the influence of Isidore’s parallel conceptions of natural law and natural language on the way that secular political hierarchies were conceived in early Irish literature. Chapter 2 shows that, in early Irish literature, natural law does not generally mean the vestigial capacity for ethics that remains to the soul after the Fall, as it does for the Latin Doctors, but the mode of inspiration by the Holy Spirit that is appropriate to the secular hierarchies. Chapters 3 and 4 concern contrasting positions on the degree to which this natural law can be politically relalised in the Christian Era. Chapter 3 outlines the influence of Eusebian triumphalism, which sees the Christian Era as the time in which the natural law may be most perfectly known. Chapter 4 discusses the influence of Augustine’s theory of the Six Ages of the World, which sees the Christian Era as less capable of embodying the natural law than former ages. Chapter 5 discusses the meaning of metamorphosis and metemphyschosis in an early Irish context, in view of their apparent incompatibility with Christian ideas concerning human nature. Chapter 6 shows that the gods of the early Irish sagas do not compromise the philosophical theology of nature discussed in the preceeding, but rather, are integral to it

3D inspection methods for specular or partially specular surfaces

Deflectometric techniques are a powerful tool for the automated quality control of specular or shiny surfaces. These techniques are based on using a camera to observe a reference pattern reflected on the surface under inspection, exploiting the dependence of specular reflections on surface normals to recover shape information from the acquired images. Although deflectometry is already used in industrial environments such as the quality control of lenses or car bodies, there are still some open problems. On the one hand, using quantitative deflectometry, the normal vector field and the 3D shape of a surface can be obtained, but these techniques do not yet take full advantage of their local sensitivity because the achieved global accuracies are affected by calibration errors. On the other hand, qualitative deflectometry is used to detect surface imperfections without absolute measurements, exploiting the local sensitivity of deflectometric recordings with reduced calibration requirements. However, this qualitative approach requires further processing that can involve a considerable engineering effort, particularly for aesthetic defects which are inherently subjective. The first part of this thesis aims to contribute to a better understanding of how deflectometric setups and their calibration errors affect quantitative measurements. Different error sources are considered including the camera calibration uncertainty and several non-ideal characteristics of LCD screens used to generate the light patterns. Experiments performed using real measurements and simulations show that the non-planarity of the LCD screen and the camera calibration are the dominant sources of error. The second part of the thesis investigates the use of deep learning to identify geometrical imperfections and texture defects based on deflectometric data. Two different approaches are explored to extract and combine photometric and geometric information using convolutional neural network architectures: one for automated classification of defective samples, and another one for automated segmentation of defective regions in a sample. The experimental results in a real industrial case study indicate that both architectures are able to learn relevant features from deflectometric data, enabling the classification and segmentation of defects based on a dataset of user-provided examples.Teknika deflektometrikoak tresna baliotsuak dira gainazal espekular edo distiratsuen kalitate kontrol automatikoa gauzatzeko. Teknika hauetan, kamera bat erabiltzen da ikuskatu beharreko gainazalean islatutako erreferentziazko patroi bat behatzeko, eta isladapen espekularrek gainazalen bektore normalengan duten menpekotasuna ustiatzen dute irudietatik informazio geometrikoa berreskuratzeko. Zenbait industria-aplikaziotan deflektometria jada erabiltzen bada ere –adibidez, betaurrekoen edo autoen karrozerien kalitate kontrolean-, oraindik badaude hobetu beharreko hainbat esparru. Batetik, deflektometria kuantitatiboak aukera ematen du gainazal baten bektore-eremu normala eta 3D forma lortzeko, baina gaur egun teknika hauek ez dute beren sentsibilitate lokal guztia aprobetxatzen kalibrazio-akatsek zehaztasun globalean duten eraginagatik. Bestetik, deflektometria kualitatiboa neurketa absoluturik egin gabe gainazal akatsak antzemateko erabili daiteke, kalibrazio-eskakizun murriztuekin sentsibilitate lokala ustiatuz. Hala ere, teknika horiek algoritmoen garapenean esfortzu handia ekar dezakeen prozesamendu bat eskatzen dute, bereziki bere baitan subjektiboak diren akats estetikoetarako. Hala ere, teknika horiek algoritmoen garapenean esfortzu handia ekar dezakeen prozesamendu bat eskatzen dute, bereziki bere baitan subjektiboak diren akats estetikoetarako. Tesi honen lehen zatiaren helburua adkizizio sistema osatzen duten gailuek eta horien kalibrazioek neurketa kuantitatiboei nola eragiten dieten hobeto ulertzen laguntzea da. Hainbat errore-iturri hartzen dira kontuan, besteak beste kameraren kalibrazioaren ziurgabetasuna, eta argi-patroiak sortzeko erabilitako LCD pantailen zenbait ezaugarri ez-ideal. Neurketa errealetan eta simulazioetan egindako esperimentuek erakusten dute LCD pantailaren deformazioak eta kameraren kalibrazioak eragindako erroreak direla neurketen akats eta ziurgabetasun iturri nagusiak. Tesiaren bigarren zatian, datu deflektometrikoetatik abiatuz, inperfekzio geometrikoak eta testura-akatsak identifikatzeko ikaskuntza sakoneko metodoen erabilera ikertzen da. Helburu honekin, irudietatik informazio fotometrikoa eta geometrikoa atera eta konbinatzen duten sare neuronal konboluzionaletan oinarritutako bi arkitektura proposatzen dira: bata, lagin akastunak automatikoki sailkatzeko; eta, bestea, laginetako eremu akastunak automatikoki segmentatzeko. Automobilgintza industriako kasu praktiko baten lortutako emaitzek erakusten dute erabilitako arkitekturek datu deflektometrikoetatik ezaugarri esanguratsuak ikas ditzaketela, erabiltzaileak emandako adibide multzo batean oinarrituta gainazal akatsak sailkatu eta segmentatzea ahalbidetuz.Las técnicas deflectométricas son una herramienta valiosa para automatizar el control de calidad de superficies especulares o reflectantes. Estas técnicas se basan en el uso de una cámara para observar un patrón de referencia reflejado en la superficie bajo inspección, explotando la dependencia de los reflejos especulares en la normal de la superficie para recuperar información geométrica a partir de las imágenes adquiridas. Aunque la deflectometría ya se usa en algunas aplicaciones industriales, tales como el control de calidad de lentes o carrocerías de coches, todavía hay algunos problemas abiertos. Por un lado, la deflectometría cuantitativa permite obtener el campo vectorial normal y la forma 3D de una superficie, pero a día de hoy no es capaz de aprovechar al máximo su sensibilidad local ya que la precisión global se ve afectada por errores de calibración. Por otro lado, la deflectometría cualitativa se utiliza para detectar imperfecciones de la superficie sin mediciones absolutas, explotando la sensibilidad local de la deflectometría con requisitos de calibración reducidos. Sin embargo, estos métodos requieren un procesamiento adicional que puede implicar un esfuerzo considerable en el desarrollo de algoritmos, particularmente para defectos estéticos que son inherentemente subjetivos. La primera parte de esta tesis tiene como objetivo contribuir a una mejor comprensión de cómo el sistema de adquisición y su calibración afectan a las mediciones cuantitativas. Se consideran dife-rentes fuentes de error, incluida la incertidumbre de calibración de la cámara y varias características no ideales de las pantallas LCD utilizadas para generar los patrones de luz. Los experimentos realizados con mediciones reales y simulaciones indican que los errores inducidos por la deformación de la pantalla LCD y la calibración de la cámara son las principales fuentes de error e incertidumbre. La segunda parte de la tesis investiga el uso del aprendizaje profundo para identificar imperfecciones geométricas y defectos de textura a partir de datos deflectométricos. Se adoptan dos enfoques diferentes para extraer y combinar información fotométrica y geométrica utilizando sendas arquitecturas basadas en redes neuronales convolucionales: una para la clasificación automatizada de muestras defectuosas y otra para la segmentación automatizada de regiones defectuosas en una muestra. Los resultados experimentales en un caso de estudio industrial real indican que ambas arquitecturas pueden aprender características relevantes de los datos deflectométricos, permitiendo la clasificación y segmentación de defectos en base a un conjunto de datos de ejemplos proporcionados por el usuario

Screening of actinobacteria for novel antimalarial compounds

The success of our first-line antimalarial treatments is threatened by increased drug resistance in Plasmodium parasites. This makes the development of novel drugs critical to combat malaria. Historically, natural products have been an excellent source of novel antimalarial compounds and thus are an ideal place to search for potential drugs. Filamentous members of the bacterial phylum, Actinobacteria, are well-known antibiotic producers, but their antimalarial potential has not been well investigated. This makes these actinobacteria a potentially valuable source of novel antimalarial compounds. To evaluate the antimalarial potential of the filamentous actinobacteria, uncharacterized environmental actinobacterial strains from the Meyers laboratory culture collection, as well as the type strains of new actinobacterial species identified and characterized in the Meyers laboratory, were screened for antiplasmodial activity against drug-sensitive Plasmodium falciparum, NF54. Liquid cultures were extracted using the mid-polar solvent, ethyl acetate, with the aim of discovering drug-like molecules that can be administered orally. Thirty-one strains of actinobacteria belonging to eight genera (Actinomadura, Amycolatopsis, Gordonia, Kribbella, Micromonospora, Nocardia, Nonomuraea, and Streptomyces) were screened revealing fourteen active strains. Eight strains were identified for further study as the displayed antiplasmodial efficacy matching predefined criteria. Of these eight candidates, Streptomyces strain PR3 was selected, as it showed excellent antiplasmodial efficacy, no cytotoxicity against Chinese Hamster Ovary (CHO) or liver HepG2 cell lines, no haemotoxicity, and was easy to culture. Bioassay-guided fractionation of the crude extracts of strain PR3, supported by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) analysis, was conducted to isolate and identify the compounds responsible for the antiplasmodial activity. During purification by solid phase extraction (SPE), a novel class of compounds was isolated. The structure of these compounds was elucidated by HRMS and NMR analysis and determined to be a series of crown ethers with a methylated backbone. These methylated crown ethers (MCE) were not produced by strain PR3, but by the cyclization of polypropylene glycol (PPG) oligomers from Amberlite® XAD-16N 20–60 mesh resin under aqueous conditions. The MCEs displayed weak antiplasmodial activity against P. falciparum NF54, without cytotoxicity against the Chinese Hamster Ovary, HepG2 cell lines, nor human erythrocytes. To the author's knowledge, the MCEs are novel compounds, and this is the first time the cyclization of PPG oligomers into crown ethers has been reported. As the MCEs were not responsible for strain PR3's potent antiplasmodial activity, further study was conducted. Using the Global Natural Product Social molecular networking (GNPS) workflow, genome mining, and NMR analysis, it was revealed that the cyclodepsipeptides, valinomycin, montanastatin, and nine other novel analogues were responsible for the high antiplasmodial activity detected. A review of the literature revealed that the structure of four of these analogues had been predicted, based on MS/MS and the biosynthesis of valinomycin. Using the same described biosynthetic logic and MS/MS analysis, two new cyclodepsipeptides, compounds 1054 and 1068, were elucidated. Unfortunately, chromatographic systems developed were unable to purify the cyclodepsipeptides, and individual evaluation of their antiplasmodial efficacy and host selectivity was not possible. The fraction containing the cyclodepsipeptides exhibited strong antiplasmodial activity against the drug-sensitive, NF54 and multidrug-resistant K1, strains of P. falciparum. No cytotoxicity was displayed against the CHO cell line and no haemotoxicity was seen against human erythrocytes. Moderate toxicity was exhibited against the liver HepG2 cell line; however, the selectivity index of the cyclodepsipeptides suggested that they are selectively targeting the Plasmodium parasites. Overall, these results are positive, and further study of the individual cyclodepsipeptides is warranted. During the investigation, discrepancies were noticed between different fractions in terms of antiplasmodial activity. These fractions contained both the MCEs and, cyclodepsipeptides along with a range of impurities, yet they displayed potent antiplasmodial activity. Further study suggested that combination of the MCEs and cyclodepsipeptides elicits a synergistic response and improves antiplasmodial efficacy. This was determined independently using two models, the fixed-ratio isobologram method and the CompuSyn programme based on the massaction law principle. The workflow developed during this investigation demonstrates how new technologies can be used to dereplicate and elucidate bioactive natural products. This workflow can be utilized to continue this research and identify new natural products that can combat malari

Military Frontiers: a Graduate Student Symposium, International Security in Three Parts: Poniard, Pen and Politician

This iteration of the Military Frontiers series of graduate student symposiums focuses on expanding the boundaries from previous conferences. This symposium will feature interdisciplinary panels whose wide array of thematic topics meet through their analysis of change in power structures. The graduate student presenters cover a breadth of history. The topics range from secret interwar period treaties between Germany and the Soviet Union to state formation during civil wars to the efficacy of drone strikes. Parties interested in military or diplomatic history, or political science are encouraged to attend and help our presenters achieve a wider perspective on their project.Ohio State UniversityMershon Center for International Security StudiesDepartment of HistoryEvent Web page, event photo

Conductivity phenomena in polycrystalline zinc oxide films

Photoconductivity and electric conductivity of polycrystalline zinc oxide thin film under low intensity irradiatio