Composite materials present challenging gaps to be studied due to their unique characteristics. The finite element method has been used to analyze composite materials subjected to the most distinctive situations. In the present work, the advantages of three element solutions studied previously are combined to develop a fourth element solution. First, decreasing the degree of the polynomials representing the axial displacement at the bottom and at the top surfaces circumvents shear locking in beams. Second, including the homogeneous solution ensures the continuity of the displacements between elements, but in this case the determination of the stiffness matrix requires a huge amount of computational time. However, it is shown that only modifications close to the original block diagonal matrix need to be considered, since far from the diagonal the contribution of the homogeneous solution is negligible. Additionally, a procedure is described to calculate a more accurate value for the stress $$\sigma _z$$ .

Abstract Cardiac catheterism is important because it offers many advantages in comparison to open surgery, for example, fewer injuries, lower risk of infections, and shorter recovery times. Simulators play a fundamental role in training packages, and virtual learning environments are less stressful. Moreover, they can also be used in certification boards and in performance assessments. A realistic and interactive simulator must be fast. In this work, the physical model of the guidewire used in catheter simulations has been improved. In particular, we determined a simple analytic expression to calculate the direction of a guidewire segment, which minimizes the total energy. The surface energy resulting from the guidewire--artery interaction and the bending energy of the guidewire is approximated up to the second order, which gives rise to interactions between segments. Furthermore, the multiple segment relaxations are introduced, enhancing the convergence especially at the beginning of the relaxation cycle. The formulas are written in matrix form of dimension 4M×4M, where M represents the number of segments varied in the update step. The method results in a more stable static solution.

This paper outlines rst the need for a performance focused intranet management framework and second, introduces a new performance metric, denoted as "Network Comfort". Network Comfort characterizes the system performance by normalizing the instantaneous performance with the best one seen during network operation so far. Network Comfort maps the performance to an easy to recognize value in the interval from zero to one. In this way, the Network Comfort is capable to describe the elasticity present in IP networks and facilitates a transparent performance management. Furthermore, the concept is extended to application and service

BACKGROUND:Information about genes, transcripts and proteins is spread over a wide variety of databases. Different tools have been developed using these databases to identify biological signals in gene lists from large scale analysis. Mostly, they search for enrichments of specific features. But, these tools do not allow an explorative walk through different views and to change the gene lists according to newly upcoming stories.RESULTS:To fill this niche, we have developed ISAAC, the InterSpecies Analysing Application using Containers. The central idea of this web based tool is to enable the analysis of sets of genes, transcripts and proteins under different biological viewpoints and to interactively modify these sets at any point of the analysis. Detailed history and snapshot information allows tracing each action. Furthermore, one can easily switch back to previous states and perform new analyses. Currently, sets can be viewed in the context of genomes, protein functions, protein interactions, pathways, regulation, diseases and drugs. Additionally, users can switch between species with an automatic, orthology based translation of existing gene sets. As todays research usually is performed in larger teams and consortia, ISAAC provides group based functionalities. Here, sets as well as results of analyses can be exchanged between members of groups.CONCLUSIONS:ISAAC fills the gap between primary databases and tools for the analysis of large gene lists. With its highly modular, JavaEE based design, the implementation of new modules is straight forward. Furthermore, ISAAC comes with an extensive web-based administration interface including tools for the integration of third party data. Thus, a local installation is easily feasible. In summary, ISAAC is tailor made for highly explorative interactive analyses of gene, transcript and protein sets in a collaborative environment.

This study investigates the potential of a software tool based on Latent Semantic Analysis (LSA; Landauer, McNamara, Dennis, & Kintsch, 2007) to automatically evaluate complex German texts. A sample of N = 94 German university students provided written answers to questions that involved a high amount of analytical reasoning and evaluation. LSA-based evaluations were compared to evaluations of six human graders. Results showed that LSA-based evaluations agreed as well with human graders as human graders agreed with each other. Agreement of human graders and LSA-based evaluations did not differ depending on the standard of comparison used by LSA, that is, whether scoring was based on one single text ("gold standard") or on a sample of previously scored assignments ("nearest neighbors"). Moreover, LSA-based evaluations of students' assignments predicted students' results in a final exam. These results show that LSA can support university teachers in giving feedback and grading complex German texts.

We compared the effects of computer assisted instruction ("conText") with an explicit strategy instruction training ("Let's Become Reading Detectives") and a non-treatment control group in a group of N = 210 sixth graders over one school year. conText is an intelligent tutoring system that uses algorithms from automatic speech processing to assess the quality of summaries and generates automatic and instant feedback. Compared to the non-treatment group, students from the intervention group considerably improved reading strategy knowledge. However, only conText improved reading comprehension. We discuss these results with regard to the general requirements of reading comprehension trainings.

Zusammenfassung:In einer Gruppe von N = 210 Hauptschülerinnen und -schülern der 6. Klasse verglichen wir die Effekte der computerunterstützten Leseverständnisförderung conText mit einer etablierten Leseverständnisintervention («Wir werden Lesedetektive») und einer unbehandelten Kontrollgruppe im Laufe eines Schuljahres. conText ist ein intelligentes tutorielles System, das die Qualität von Textzusammenfassungen mithilfe von Verfahren aus dem Bereich der automatischen Sprachverarbeitung bewertet und an die Schüler zurückmeldet. Im Vergleich zu einer unbehandelten Kontrollgruppe verbesserten beide Interventionen das Lesestrategiewissen, jedoch erwies sich nur conText im Hinblick auf die Verbesserung des Leseverständnisses als erfolgreich. Die Ergebnisse werden im Hinblick auf die Rahmenbedingungen von Leseverständnisinterventionen diskutiert.

There are many established reading strategy training programmes, which explicitly teach strategic and meta‐cognitive knowledge to improve reading comprehension. Although instruction in strategy knowledge leads to improvements in meta‐cognitive skills, the effects do not always transfer to reading comprehension. Therefore, to investigate preconditions for knowledge transfer, two different strategy training programmes were implemented in nine classes of Grade 6 students (N = 148) over the course of one school year. One programme involved teacher‐directed instruction of declarative meta‐cognitive knowledge (Reading Detectives; Rühl & Souvignier, 2006). The other aimed at improving executive meta‐cognition by guided practice: students worked with a computer program based on latent semantic analysis (LSA) (conText) and received immediate feedback on written summaries. Although both groups improved their strategy knowledge to the same extent, the conText group showed a greater improvement in reading comprehension. These fndings suggest that guided practice, which is characterised by intensive practice and individualised corrective feedback, is superior to explicitly teaching strategy knowledge.

Latent Semantic Analysis (LSA) is a technique from the field of natural language processing. Its method is completely statistical in nature, which permits to extract the relations between words based on their common occurrences in texts without any specification of rules or dictionaries. Despite the fact that LSA is only a statistical technique and does not yield real verbal intelligence, it exhibits an astonishing degree of expertise on tasks that afford verbal intelligence and semantic knowledge. The SUMMA platform is a robust and flexible technology that supports the users during the complete LSA development and test cycles. Furthermore, it can be used for productive purposes. The core of the system is the server. Several client applications ratify its effectiveness, versatility and confirm the viability of the LSA technology. The server is platform independent, supports most of the language encodings, and allows clients’ remote communication and extensions to match individual requirements. The present paper discusses how SUMMA attaches the main phases in LSA development and test cycles and presents empirical results from applications. RESUME. L’Analyse de la Semantique Latente (LSA) est une technique qui releve du traitement automatique du langage naturel. Sa methode est totalement statistique par nature, ce qui permet d’extraire des relations entre les mots basees sur leurs occurrences communes dans des textes sans avoir a specifier des regles ou a recourir a des dictionnaires. En depit du fait que LSA ne soit qu’une technique statistique, LSA temoigne d’un etonnant degre d’expertise Studia Informatica Universalis. dans des tâches qui requierent de l’intelligence verbale et des connaissances semantiques. La plateforme SUMMA est une technologie robuste et flexible qui assiste les utilisateurs durant le developpement et les tests de LSA. De plus, la plateforme SUMMA peut etre utilisee a des foins applicatives. Le cœur du system est une serveur. Plusieurs applications client confirment son efficacite, sa polyvalence et confirment la viabilite de la technologie LSA. Le serveur est independant de la plateforme, il supporte la plupart des langages d’encodage, et permet des communications clients a distance ainsi que des extensions correspondant a des besoins specifiques. Le present article discute de la maniere dont SUMMA articule les phases principales de developpement et les cycles de test puis presente les resultants empiriques obtenus lors de diverses applications.

The validity of constructed-response items like essays that are commonly used within informal diagnostics is threatened by many biases. Computer based essay scoring reduces these biases. Latent semantic analysis (LSA) is a statistical technique that allows the representation of human semantic knowledge structures within the computer, thus enabling automatic essay scoring. This article describes the basic steps for implementing a LSA-based system in German language and examines its performance on multiple-choice knowledge tests and essay scoring. It showed an equal performance compared to university students in classifying animal species and achieved medium to high correlations with human raters in essay scoring. Using cumulated scores, the correlations reached values necessary for the reliability of standardized tests. Besides essay scoring, intelligent tutoring software and the extension of psychological models by semantic modules are further interesting fields of application for LSA.

Zusammenfassung. Das Schreiben von Kurzaufsätzen im Rahmen informeller Diagnostik ist weit verbreitet, jedoch mit Problemen der Auswertungsobjektivität behaftet. Durch die computerbasierte Bewertung von Essays lassen sich Entscheidungsheuristiken vermeiden. Die latente semantische Analyse (LSA) ist ein statistisches Verfahren, dass die Repräsentation von Wissensstrukturen im Computer und somit die automatische inhaltliche Bewertung von Aufsätzen ermöglicht. Es wird die Entwicklung eines deutschsprachigen LSA-basierten Systems beschrieben und seine Leistungsfähigkeit in einem Multiple-Choice-Wissenstest, sowie bei der Bewertung von Aufsätzen aufgezeigt. Bei der Klassifikation von Tierarten nach Klassen erzielte es vergleichbare Leistungen wie Studierende. Bei der Bewertung von Aufsätzen wurden Korrelationen mit menschlichen Bewertern im mittleren bis oberen Bereich erzielt. Die Übereinstimmung von Summenscores mehrerer Aufgaben reicht an für standardisierte Verfahren geforderte Reliabilitätskennwerte heran. Neben der automatischen Aufsatzbeantwortung liegen Anwendungen v.a. in intelligenter Lernsoftware und der Ergänzung bestehender psychologischer Modelle durch semantische Module.

Tutors have only limited time to support the learning process. In this paper, we introduce a model that helps answering the questions of students. The model invokes the knowledge and skills of fellow students by bringing them together based on the combination of question posed and their study progress and supports them with text fragments selected from the material studied. We will explain how we used LSA to select and support these peers; examine the calibration of the LSA-parameters and conclude with a small practical simulation to show that the results of our model are fit for use in experiments with students.

Nowadays, there exists a great interest in development of mobile and teleoperated or even autonomous robots, which could replace humans in dangerous tasks. Information management and system architecture in these can stand for a difficult issue even with a single teleoperated robot. Considering a system of multiple human and robot entities working together in teams at different locations, complexity of information management rapidly grows. This paper sketches an information exchange and handling design in heterogenous human-robot teams, employing teleoperation of semi-autonomous robots and humans in rescue test-cases. The paper addresses analysis of the system design as well as particular tasks specifics connected with this issue.

Mobile robots can be of significant support for human teams in search and rescue situations. A user requirement analysis on basis of questionnaires distributed to fire fighters and emergency support people expresses notable interest in sending teleoperated robots into dangerous areas instead of risking human life. This paper summarises the requirements and the consequences for a telematic system with an intuitive user interface, which supports quick reaction capabilities. Design and implementation of an infrastructure addressing data flow in joint teams of humans and robots for data sharing, teleoperations and remote coordination are presented. Furthermore, robot vehicles used in that context and test scenarios are described.

Motivated by results on interactive proof systems we investigate the comput ational power of quantifiers applied to well-known complexity classes. In special, we are interested in existential, universal and probabilistic bounded error quantifiers ranging over words and sets of words, i.e. oracles if we think in a Turing machine model. In addit ion to the standard oracle access mechanism, we also consider quantifiers ranging ov er oracles to which access is restricted in a certain way. We first examine an9-8-hierarchy overPusing words quantifiers as well as two types of set quantifiers. This hierarchy of classes is called the analytic polynomial -ti e hierarchy. We show that each class of this hierarchy coincides with one of the classe s p k and p k (k 0) of the (arithmetic) polynomial-time hierarchy, PSPACE, or one of the classes exp k and exp k (k 1) of the exponential-time alternation hierarchy and vice versa. We next consider a hierarchy which refines the analytic polynomial-time hierarchy by considering restrictions on the number of oracle queries, the so called bounded analytic polynomial-time hierarchy. We characterize classes of this hierar chy by well-known complexity classes. In particular, we show that each class from this hie rarchy having a certain normal form coincides with one of the classes NP, coNP, PSPACE, exp k or exp k (k 1) and vice versa. All these characterizations remain valid if the queri es are asked in a nonadaptive form, i.e. in “parallel”. We also study a hierarchy which can intuitively be interpreted as the analyt ic polynomial-time hierarchy defined over L instead ofP, i.e. an9-8-hierarchy overL using word quantifiers as well as two types of set quantifiers. This hierarchy is called the analytic logarithmic-space hierarchy. We show that every class of this hierarchy ca n be represented in a certain normal form and characterize such classes by well-known com plexity classes. In particular, each class whose last quantifier is a word quantifier coincides with one of the classesL, p k or p k (k 1) and vice versa. Furthermore, we examine probabilistic bounded error quantifiers. For instance, using the restricted oracle access mechanism we characterize (one prove r) interactive proof systems by an existential set quantifier and a probabilistic bounded error word quanti fier applied toP, and show that a bounded error set quantifier applied to PSPACEcan be eliminated without changing the class in question. Finally, we discuss the relativizability of the results. Zusammenfassung Angeregt durch die Resultate über interaktive Beweissysteme untersuchen wi r Quantoren in Anwendung auf bereits bekannte Komplexitätsklassen hinsichtlich ihrer dadu ch gegebenen Berechnungsmächtigkeit. Von besonderem Interesse sind dabei existenti lle und universelle Quantoren sowie Quantoren mit begrenzter Fehlerwahrscheinli chkeit, die alle über Wörter oder Wortmengen (Orakel im Kontext der Turingmaschinen) quantifi zieren. Außer in bezug auf den Standardmechanismus eines Orakelzugriffs werde n auch Quantifizierungen über Orakel, für deren Zugriff gewisse Beschränkungen best ehen, betrachtet. Zuerst beschäftigen wir uns mit einer 9-8-Hierarchie überP, wobei sowohl Wortquantoren als auch zwei verschiedene Typen von Mengenquantoren verwendet werden. Die so entstehende Klassenhierarchie nennen wir die analytische Polynomialzeit-Hierarchie . Es zeigt sich, daß jede Klasse dieser Hierarchie mit einer der Klassen k oder p k (k 1) der (arithmetischen) Polynomialzeit-Hierarchie, mit PSPACEoder mit einer der Klassen k oder exp k (k 1) der alternierenden Exponentialzeit-Hierarchie zusammenfällt. Auch die Umkehrung gilt; jede der aufgeführten Klassen läßt sich durch eine der Kl assen aus der analytischen Polynomialzeit-Hierarchie ausdrücken. Als nächstes wird eine Hierarchie betrachtet, die die analytische Polynom ialzeit-Hierarchie durch die Einbeziehung von Anzahlbegrenzungen der Orakelfragen verfeinert: di e sogenanntebeschr̈ ankte analytische Polynomialzeit-Hierarchie . Wir charakterisieren die Klassen dieser Hierarchie durch bekanntere Komplexitätsklassen, und zeige n insb sonders, daß jede Klasse der Hierarchie, die einer bestimmten Normalform ge nügt, einer der KlassenNP, coNP, PSPACE, exp k oder exp k (k 1) entspricht. Auch hier ist die Umkehrung der Aussage ebenfalls richtig. Darüber hinaus bleiben alle Charaktie risierungen gültig, wenn Orakelfragen ausschließlich nicht-adaptiv, also in gew iss m Sinne parallel gestellt werden können. Wir studieren auch eine Hierarchie, die intuitiv als analytische Polynomial zeit-Hierarchie überL anstelle vonP interpretiert werden kann, d.h. die 9-8-Hierarchie überL sowohl bezüglich der Wortquantoren als auch bezüglich der zwei Typen von Mengenquantoren. Diese Hierarchie wird die analytische Hierarchiëuber logarithmischem Raum genannt. Wir zeigen, daß jede Klasse dieser Hierarchie in eine bestimmte N ormalform gebracht werden kann, und charakterisieren solche Klassen dann mit Hilfe berei ts bekannter Komplexitätsklassen. Dabei stellt sich heraus, daß jede Klasse, deren letzter Quantor ein Wortquantor ist, mitL, p k oder p k (k 1) identisch ist, und umgekehrt. Weiterhin untersuchen wir Quantoren mit begrenzter Fehlerwahrscheinlichke it. Beispielsweise ist die Klasse der mittels interaktiven Beweissystemen in Polynomialzeit entscheidbaren Mengen, die Klasse IP, im Kontext polynomieller Zeitressourcen durch einen Existenzquantor in Verbindung mit einem Quantor mit begrenzter Fehlerwahrscheinli keit ausdrückbar, wenn man den Mechanismus für die Orakelzugriffe einschr ̈ ankt. Es zeigt sich, daß ein Mengenquantor mit begrenztem Fehler, angewendet auf PSPACE, eliminiert werden kann, ohne die Klasse zu verändern. Abschließend gehen wir auf die Relativierbarkeit der Resultate ein.

Under the assumption EXPTIME 6= NEXPTIME, we show the nonexistence of polynomial-time bounded-error approximation algorithms solving the M AX -Selection problem. In addition, a linear reduction from the MAX 2SAT problem to the MAX -Selection problem is given. Therefore, if there exists a polynomial-time approximation scheme for the M AX -Selection problem, then P= NP.

This report is a rather concise summary of the first-named author's M. Sc. Dissertation, written under the second-named author's supervision.The matching problem in graphs consists in determining matchings,that is, vertex disjoint sets of edges of the graph. In particular,we are interested in finding maximum matchings, that is, matchingsof maximum cardinality. There are many variations aroundthis problem, the graph can be: bipartite or not, weighted or not.In this work we describe...

During rescue operations fire fighters encounter often life-dangerous situations. Robots can assist to relieve the humans from dangerous tasks. Yet, at least for the near future, robots can only complement the human rescue personnel, who are endowed with far better adaptive capabilities. This paper presents an approach by joint teams of humans and robots working together under the management of a remote coordinator. The design of the system is based on the results of a user requirement analysis. The performance of the team is improved by means of localization features for robots and humans, data sharing between the team, planning capabilities, teleoperation and remote coordination attributes.