The Application of Approximation and Complexity Theory Methods to the Solution of Computer Vision Problems

We survey aspects of approximation and complexity theory and their application to the numerous computer vision problems that require an approximate solution because only partial information is available. We consider ill-posed computer vision problems and the methods that can be employed towards reformulating them as well-posed. We are particularly interested in the surface reconstruction problem that is encountered in the construction of the 2 1/2-D sketch, and which has been formulated and solved using different methods. We apply regularization theory, information-based complexity, and other methods to the solution of this problem. Finally, the shape from shadows problem is formulated and the optimal error algorithm is constructed and analyzed

The derivation of two-dimensional surface shape from shadows

We study theoretical and implementation issues that arise when solving the shape from shadows problem. In this problem, the shadows created by a light falling on a surface are used to recover the surface itself. The problem is formulated and solved in a Hilbert space setting. We construct the spline algorithm that interpolates the data and show that it is the best possible approximation to the original function. The optimal error algorithm is implemented and a series of tests is shown. We additionally show that the problem can be decomposed into subproblems and each one can be solved independently from the others. This decomposition is suited to parallel computation and can result in considerable reductions in the cost of the solution

The Application of Approximation and Complexity Theory Methods to the Solution of Computer Vision Problems

We survey aspects of approximation and complexity theory and their application to the numerous computer vision problems that require an approximate solution because only partial information is available. We consider ill-posed computer vision problems and the methods that can be employed towards reformulating them as well-posed. We are particularly interested in the surface reconstruction problem that is encountered in the construction of the 2 1/2-D sketch, and which has been formulated and solved using different methods. We apply regularization theory, information-based complexity, and other methods to the solution of this problem. Finally, the shape from shadows problem is formulated and the optimal error algorithm is constructed and analyzed

“It is more than true that television reproduces life”: The effect of Greek rhetorical conventions on Greek learners’ academic writing in English

This paper proposes a framework for analysing stance in argumentative essays written by Greek advanced learners of English. The essays are included in the Greek Corpus of Learner English (GRICLE). Their analysis showed that Greek learners point to their attitude mainly by using lexical chunks such as it is true that, it is a fact that, it is obvious that. Using such chunks allows students to defer commitment to the stated proposition, thereby presenting it as a commonly accepted fact. This technique is considered to be culturally induced as it is a typical rhetorical convention commonly followed in L1 writing

Discourse organising nouns in American and Greek university students’ argumentative essays: A contrastive study

This paper investigates how argumentation is constructed through nouns in argumentative essays. Data are drawn from the Greek Corpus of Learner English (GRICLE) and two native corpora (LOCNESS and PELCRA).  The study focuses on illocutionary, language activity and mental process nouns (cf. Francis 1994). Native speakers use more discourse organising nouns than Greek students and incorporate them effectively in their argumentation. These nouns have a clear cohesive function, can be modified by adjectives or a reference can be made to them. Greek students use those nouns mostly to refer to the prompt of the essay and provide agreement or disagreement with the topic

A regularized solution of shape from shadows

We present a regularized solution to the shape from shadows problem. In this problem the shadows cast on an unknown surface yield data that can be used for the reconstruction of this surface. In the simulation presented here we assume that the data can now be perturbed by noise. It is shown that the regularized approach produces a solution that can handle noisy information while being very similar to the solution obtained by the approximation theoretic approaches used in earlier work. We provide implementation runs where the performance of the algorithm in recovering unknown surfaces is tested. Furthermore, we study the visual effects of smoothing on the various reconstructions

Effect of temperature on the strength development of mortar mixes with GGBS and fly ash

The concrete mixes used in this study had 28 d mean strengths of 50 and 30 MPa and also had Portland cement (PC) partially replaced with ground granulated blast-furnace slag (GGBS) and fly ash (FA). These mixes were the same as those used in a UK-based project that involved casting of blocks, walls and slabs. The strength development of ‘equivalent’ mortar mixes was determined in the laboratory for curing temperatures of 10, 20, 30, 40 and 50°C. High curing temperatures were found to have a beneficial effect on the early-age strength, but a detrimental effect on the long-term strength. GGBS was found to be more sensitive to high curing temperatures than PC and FA, as reflected in its higher ‘apparent’ activation energy. The accuracy of strength estimates obtained from maturity functions was examined. The temperature dependence of the Nurse–Saul function (i.e. concrete strength gain rate varies linearly with temperature) was not sufficient to account for the improvement in early-age strengths resulting from high curing temperatures. The Arrhenius-based function, on the other hand, overestimated them because of the detrimental effect of high curing temperature on strength starting from a very early age. Both functions overestimated the long-term strengths, as neither function accounts for the detrimental effect of high curing temperatures on the ultimate compressive strength. </jats:p

Development of a new ultra sensitive real-time PCR assay (ultra sensitive RTQ-PCR) for the quantification of HBV-DNA

<p>Abstract</p> <p>Background</p> <p>Improved sensitivity of HBV-DNA tests is of critical importance for the management of HBV infection. Our aim was to develop and assess a new ultra sensitive in-house real-time PCR assay for HBV-DNA quantification (ultra sensitive RTQ-PCR).</p> <p>Results</p> <p>Previously used HBV-DNA standards were calibrated against the WHO 1^stInternational Standard for HBV-DNA (OptiQuant^®HBV-DNA Quantification Panel, Accrometrix Europe B.V.). The 95% and 50% HBV-DNA detection end-point of the assay were 22.2 and 8.4 IU/mL. According to the calibration results, 1 IU/mL equals 2.8 copies/mL. Importantly the clinical performance of the ultra sensitive real-time PCR was tested similar (67%) to the Procleix Ultrio discriminatory HBV test (dHBV) (70%) in low-titer samples from patients with occult Hepatitis B. Finally, in the comparison of ultra sensitive RTQ-PCR with the commercially available COBAS TaqMan HBV Test, the in-house assay identified 94.7% of the 94 specimens as positive versus 90.4% identified by TaqMan, while the quantitative results that were positive by both assay were strongly correlated (<it>r </it>= 0.979).</p> <p>Conclusions</p> <p>We report a new ultra sensitive real time PCR molecular beacon based assay with remarkable analytical and clinical sensitivity, calibrated against the WHO 1^stInternational standard.</p

Exploring European Writing Cultures : Country Reports on Genres, Writing Practices and Languages Used in European Higher Education

At European universities, writing is a traditional way of learning, assessment, and independent study, but it is handled in an implicit, tradition-based way that has only recently been contrasted with and supported by a more explicit writing ped-agogy. Still, little systematic knowledge is available about the pedagogical ap-proaches to writing, writing practices, and genres across Europe and much of it is codified in the national languages without correlation to internationally accept-ed terminology and theories. This book explores the writing cultures of Europe, nation by nation, and reports the idiosyncrasies for each respective country. The reports are based on a 17-item topic list used by the authors to collect data be-fore synthesizing the results. Next to writing practices and genres, a high level of emphasis was placed on the structure of educational systems, the languages in use, and the kind of support provided for student writers. Note: This research project has been conducted within the framework of COST Action IS0703 “European Research Network on Learning to Write Effectively”, funded by the European Union. We are also thankful to Christiane Donahue, Eliza Kitis, Charles Bazerman, Helmut Gruber, and David Russell for their cooperation and support in this project.Wissenschaftliches Schreiben an europäischen Hochschulen ist eine herkömmliche Form des Lernens, Prüfens und autonomen Studierens, auch wenn es in einer impliziten, eher auf Tradition denn auf bewusster Didaktik beruhenden Weise eingesetzt wird. Wenig auf systematische Weise erhobenes vergleichendes Wissen gibt es bislang über Schreibpraktiken, Genres und schreibdidaktische Ansätze in Europa und das, was an Wissen existiert ist oft in den nationalen Sprachen verfasst, die nicht mit internationalen Terminologien und Theorien der Schreibwissenschaft verbunden sind. Der vorliegende Band untersucht Schreibkulturen in Europa Land für Land und berichtet was jeweils hervorsticht. Die Berichte basieren auf einer 17-Item Themenliste, nach der die Autorenteams Daten über ihr jeweiliges Land sammelten, bevor sie es zu einem Bericht synthetisierten. Neben Schreibpraktiken und Genres werden dabei die Struktur des jeweiligen Bildungssystems, die verwendeten Sprachen und die besondere Schreibdidaktik hervorgehoben. Anmerkung: Das Projekt wurde im Rahmen der COST Aktion IS0703 “European Research Network on Learning to Write Effectively” durchgeführt, das von der EU finanziert wird. Wir bedanken uns bei Christiane Donahue, Eliza Kitis, Charles Bazerman, Helmut Gruber und David Russell für ihre Unterstützung und Mitwirkung in diesem Projekt.At European universities, writing is a traditional way of learning, assessment, and independent study, but it is handled in an implicit, tradition-based way that has only recently been contrasted with and supported by a more explicit writing ped-agogy. Still, little systematic knowledge is available about the pedagogical ap-proaches to writing, writing practices, and genres across Europe and much of it is codified in the national languages without correlation to internationally accept-ed terminology and theories. This book explores the writing cultures of Europe, nation by nation, and reports the idiosyncrasies for each respective country. The reports are based on a 17-item topic list used by the authors to collect data be-fore synthesizing the results. Next to writing practices and genres, a high level of emphasis was placed on the structure of educational systems, the languages in use, and the kind of support provided for student writers. Note: This research project has been conducted within the framework of COST Action IS0703 “European Research Network on Learning to Write Effectively”, funded by the European Union. We are also thankful to Christiane Donahue, Eliza Kitis, Charles Bazerman, Helmut Gruber, and David Russell for their cooperation and support in this project