Range mode and range median queries in constant time and sub-quadratic space

Given a list of n items and a function defined over sub-lists, we study the space required for computing the function for arbitrary sub-lists in constant time.For the function mode we improve the previously known space bound O(n²/logn) to O(n²loglogn/log²n) words.For median the space bound is improved to O(n²loglog²n/log²n) words from O(n²⋅log(k)n/logn), where k is an arbitrary constant and log(k) is the iterated logarithm.     

The State of the Art in Topology‐Based Visualization of Unsteady Flow

Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Methods based on vector field topology are known for their convenience for visualizing and analysing steady flows, but a counterpart for unsteady flows is still missing. However, a lot of good and relevant work aiming at such a solution is available. We give an overview of previous research leading towards topology‐based and topology‐inspired visualization of unsteady flow, pointing out the different approaches and methodologies involved as well as their relation to each other, taking classical (i.e. steady) vector field topology as our starting point. Particularly, we focus on Lagrangian methods, space–time domain approaches, local methods and stochastic and multifield approaches. Furthermore, we illustrate our review with practical examples for the different approaches.     

Confluence and Semantics of Constraint Simplification Rules

Constraint Simplification Rules (CSR) is a subset of the Constraint Handling Rules (CHR) language. CHR is a powerful special-purpose declarative programming language for writing constraint solvers. The CSR subset of CHR forms essentially a committed-choice language consisting of guarded rules with multiple heads that replace constraints by simpler ones until they are solved. This paper gives declarative and operational semantics as well as soundness and completeness results for CSR programs.We also introduce a notion of confluence for CSR programs. Confluence is an essential syntactical property of any constraint solver. It ensures that the solver will always compute the same result for a given set of constraints independent of which rules are applied. It also means that it does not matter for the result in which order the constraints arrive at the constraint solver.We give a decidable, sufficient and necessary syntactic condition for confluence of terminating CSR programs. Moreover, as shown in this paper, confluence of a program implies consistency of its logical meaning (under a mild restriction).     

Nonlinear ceramics for tunable microwave devices

The research on materials and systems for tunable microwave devices has gained attraction within the last years. The radio frequency characterization and the component design of tunable microwave components based on dielectric ceramics especially barium-strontium-titanate (BST) are presented in this second part, whereas the basic material properties are discussed in detail in the first part. After a short introduction to the processing technology used for the fabrication of tunable components based on a BST thick film, the relations between microwave properties and material properties as well as the microstructure are presented in detail. The design process for tunable microwave components based on BST thick films is described. Especially the considerations related to micro- and macrostructure and their connection are highlighted. The paper closes with two different application examples: a reconfigurable array antenna for satellite communication and varactors for high power applications.     

Interactive lectures: Effective teaching and learning in lectures using wireless networks

Among the severe instructional shortcomings of lectures is their lack of interactivity. To overcome these problems, the learning environment of the interactive lecture is introduced, in which students and lecturer interact by using mobile computers in a wireless network. In an experimental study, 44 students participated in interactive and in conventional lecture meetings. A quiz service that allowed question to be posted, students’ answers to be evaluated, and the results to be presented graphically, was implemented on mobile computers. The participants rated the interactive condition better, also reporting higher levels of attention, activity and perceived learning success for this condition. Objective measures indicated a slight but insignificant difference toward better learning results in the interactive condition.     

Visualizing transport structures of time-dependent flow fields

This article focuses on the transport characteristics of physical properties in fluids-in particular, visualizing the finite-time transport structure of property advection. Applied to a well-chosen set of property fields, the proposed approach yields structures giving insights into the underlying flow's dynamic processes.     

COLLATE – A collaboratory supporting research on historic European films

In the COLLATE project, we aim to design and implement a Web-based collaboratory for archives, scientists, and end users working with digitized cultural material. Our example domain is the historic film documentation comprising digitized material about European films of the early 20th century. Designed as a content- and context-based knowledge working environment for distributed user groups, the COLLATE system supports both individual work and collaboration of domain experts who are analyzing, evaluating, indexing, and annotating material in the data repository. The system provides appropriate task-based interfaces for indexing and annotating. As a multifunctional means of in-depth analysis, annotations can be made individually but also collaboratively, for example in the form of annotation of annotations. Combining results from manual and automatic indexing procedures, elaborate content- and context-based information retrieval mechanisms can be applied.