Three-Dimensional Analysis of Spiny Dendrites Using Straightening and Unrolling Transforms

Current understanding of the synaptic organization of the brain depends to a large extent on knowledge about the synaptic inputs to the neurons. Indeed, the dendritic surfaces of pyramidal cells (the most common neuron in the cerebral cortex) are covered by thin protrusions named dendritic spines. These represent the targets of most excitatory synapses in the cerebral cortex and therefore, dendritic spines prove critical in learning, memory and cognition. This paper presents a new method that facilitates the analysis of the 3D structure of spine insertions in dendrites, providing insight on spine distribution patterns. This method is based both on the implementation of straightening and unrolling transformations to move the analysis process to a planar, unfolded arrangement, and on the design of DISPINE, an interactive environment that supports the visual analysis of 3D patterns

eCITY: Evolutionary software architecture visualization - an evaluation

An essential component in the evolution and maintenance of large-scale software systems is to track the structure of a software system to explain how a system has evolved to its present state and to predict its future development. Current mainstream tools facilitating the structural evolution of software architecture by visualization are confined with easy to integrate visualization techniques such as node-link diagrams, while more applicable solutions have been proposed in academic research. To bridge this gap, we have incorporated additional views to a conventional tool that integrates an interactive evolving city layout and a combination of charts. However, due to a limited access to the stakeholders it was not possible to solicit them for a formal modeling process. Instead, an early prototype was developed and a controlled experiment was conducted to illustrate the vital role of such in-situ visualization techniques when aiming to understanding the evolution of software architecture

Effects of state-dependent balking on multi-server non-stationary queueing systems

A combination of discrete-time modelling and theoretical analysis is used to develop an easy-to-use Normal approximation for the time-dependent behaviour of multi-server queueing systems subject to state-dependent balking. Key ndings that underpin the approximation are that time lags between peaks in arrival rates and congestion levels can be ignored; queue behaviour is insen- sitive to distribution of service time beyond its mean; and distribution of number in the system is near Normal. This model is then used to derive valuable management implications for service orientated systems where delays are frequent and abandonments are an important feature. Key insights are that such systems can often adopt very `sub-optimal' behaviour, and that customer impatience can be very beneficial where management wishes to improve system performance. `Optimal' performance is defined, and practical measures for queue managers to move system performance towards `optimality' are identified

Visual Online Analytical Processing (OLAP)

An umbrella term encompassing a new generation of online analytical processing (OLAP) end user tools for interactive ad hoc exploration of large multidimensional data volumes. Visual OLAP provides a comprehensive framework of advanced visualization techniques for representing the retrieved data set along with a powerful navigation and interaction scheme for specifying, refining, and manipulating the subset of interest. The concept emerged from the convergence of business intelligence (BI) techniques and the achievements in the areas of information visualization and visual analytics. Traditional OLAP frontends, designed primarily to support routine reporting and analysis, use visualization merely for expressive presentation of the data. In the visual OLAP approach, however, visualization plays the key role as the method of interactive query-driven analysis. Comprehensive analysis includes a variety of tasks such as examining the data from multiple perspectives, extracting useful information, verifying hypotheses, recognizing trends, revealing patterns, gaining insight, and discovering new knowledge from arbitrarily large and/or complex data volumes. In addition to conventional operations of analytical processing, such as drill-down, roll-up, slice-and-dice, pivoting, and ranking, visual OLAP supports further interactive data manipulation techniques, such as zooming and panning, filtering, brushing, collapsing, etc

Diethart Kerbs/Jürgen Reulecke (Hrsg.): Handbuch der deutschen Reformbewegungen. Wuppertal: Hammer 1998. [Rezension]

Rezension von: Diethart Kerbs/Jürgen Reulecke (Hrsg.): Handbuch der deutschen Reformbewegungen. Wuppertal: Hammer 1998. 624 S