Visual Analysis of Multi‐Joint Kinematic Data

Kinematics is the analysis of motions without regarding forces or inertial effects, with the purpose of understanding joint behaviour. Kinematic data of linked joints, for example the upper extremity, i.e. the shoulder and arm joints, contains many related degrees of freedom that complicate numerical analysis. Visualisation techniques enhance the analysis process, thus improving the effectiveness of kinematic experiments. This paper describes a new visualisation system specifically designed for the analysis of multi‐joint kinematic data of the upper extremity. The challenge inherent in the data is that the upper extremity is comprised of five cooperating joints with a total of fifteen degrees of freedom. The range of motion may be affected by subtle deficiencies of individual joints that are difficult to pinpoint. To highlight these subtleties our approach combines interactive filtering and multiple visualisation techniques. Our system is further differentiated by the fact that it integrates simultaneous acquisition and visual analysis of biokinematic data. Also, to facilitate complex queries, we have designed a visual query interface with visualisation and interaction elements that are based on the domain‐specific anatomical representation of the data. The combination of these techniques form an effective approach specifically tailored for the investigation and comparison of large collections of kinematic data. This claim is supported by an evaluation experiment where the technique was used to inspect the kinematics of the left and right arm of a patient with a healed proximal humerus fracture, i.e. a healed shoulder fracture.     

Modeling assessment for re-use of traditional and new types of assessment

In the new learning approach assessment is integrated in learning and instruction and addresses complex traits (the abilities, the characteristics in a specific domain) of students. To match this new approach, new types of assessment are developed, like peer assessment or competence assessment. The development of these new assessments is an expensive and intensive activity. Exchange initiatives promise to reduce those efforts by the re-use of materials. But they also raise questions: is it a complete assessment or are there specific parts of an assessment that can be re-used? And is re-use limited to particular item formats? In order to support the re-use of both new and traditional assessment types an educational model for assessment is developed.In this article we present this model. The model is validated against [Stiggins, R. J. (1992). Het ontwerpen en ontwikkelen van performance-assessment toetsen [Design and development of performance assessments]. In J. W. M. Kessels, & C. A. Smit (Eds.). Opleiders in organisaties/Capita Selecta (pp. 75–91). Deventer: Kluwer (afl. 10)] guidelines for the development of performance assessments, the four-process framework of [Almond, R. G., Steinberg, L., & Mislevy, R. J. (2001). A sample assessment using the four-process framework. CSE Report 543. Center for study of evaluation, University of California, Los Angeles. Retrieved November 15, 2005 from http://www.cse.ucla.edu/cresst/reports/tech543.pdf; Almond, R. G., Steinberg, L., & Mislevy, R. J. (2003). A four-process architecture for assessment delivery, with connections to assessment design. CSE Report 616. Center for study of evaluation. University of California, Los Angeles], a specification for the exchange and interoperability of assessments and performance assessment as a new type of assessment. The educational model for assessment gives new input to the alignment of the teaching, learning and assessment.     

Resolution Independent NPR-Style 3D Line Textures

This work introduces a technique for interactive walk-throughs of non-photorealistically rendered (NPR) scenes using three-dimensional (3D) line primitives to define architectural features of the model, as well as indicate textural qualities. Line primitives are not typically used in this manner in favour of texture mapping techniques which can encapsulate a great deal of information in a single texture map, and take advantage of GPU optimizations for accelerated rendering. However, texture mapped images may not maintain the visual quality or aesthetic appeal that is possible when using 3D lines to simulate NPR scenes such as hand-drawn illustrations or architectural renderings. In addition, line textures can be modified interactively, for instance changing the sketchy quality of the lines. The technique introduced here extracts feature edges from a model, and using these edges, generates a reduced set of line textures which indicate material properties while maintaining interactive frame rates. A clipping algorithm is presented to enable 3D lines to reside only in the interior of the 3D model without exposing the underlying triangulated mesh. The resulting system produces interactive illustrations with high visual quality that are free from animation artifacts.     

A User Study of Visualization Effectiveness Using EEG and Cognitive Load

Effectively evaluating visualization techniques is a difficult task often assessed through feedback from user studies and expert evaluations. This work presents an alternative approach to visualization evaluation in which brain activity is passively recorded using electroencephalography (EEG). These measurements are used to compare different visualization techniques in terms of the burden they place on a viewer's cognitive resources. In this paper, EEG signals and response times are recorded while users interpret different representations of data distributions. This information is processed to provide insight into the cognitive load imposed on the viewer. This paper describes the design of the user study performed, the extraction of cognitive load measures from EEG data, and how those measures are used to quantitatively evaluate the effectiveness of visualizations.     

A dynamic model, including contact bounce, of an electrostaticallyactuated microswitch

Microelectromechanical devices are increasingly being integrated into electronic circuitry. One of these types of devices is the microswitch, which acts much like a three-terminal field-effect transistor (FET). While various microswitches are currently being developed, their dynamic behavior is not well understood. Upon closing, switches bounce several times before making permanent contact with the drain. In this paper, a time-transient finite difference analysis is used to model the dynamic behavior of two different electrostatically actuated microswitch configurations. The model uses dynamic Euler-Bernoulli beam theory for cantilevered beams, includes the electrostatic force from the gate, takes into account the squeeze-film damping between the switch and substrate, and includes a simple spring model of the contact tips. The model and simulation can be used as design tools to improve switch performance and reduce switch bounce in future designs     

ASC: an associative-computing paradigm

Today's increased computing speeds allow conventional sequential machines to effectively emulate associative computing techniques. We present a parallel programming paradigm called ASC (ASsociative Computing), designed for a wide range of computing engines. Our paradigm has an efficient associative-based, dynamic memory-allocation mechanism that does not use pointers. It incorporates data parallelism at the base level, so that programmers do not have to specify low-level sequential tasks such as sorting, looping and parallelization. Our paradigm supports all of the standard data-parallel and massively parallel computing algorithms. It combines numerical computation (such as convolution, matrix multiplication, and graphics) with nonnumerical computing (such as compilation, graph algorithms, rule-based systems, and language interpreters). This article focuses on the nonnumerical aspects of ASC     

Two-dimensional packing with conflicts

We study the two-dimensional version of the bin packing problem with conflicts. We are given a set of (two-dimensional) squares V = {1, 2, . . . ,n} with sides and a conflict graph G = (V, E). We seek to find a partition of the items into independent sets of G, where each independent set can be packed into a unit square bin, such that no two squares packed together in one bin overlap. The goal is to minimize the number of independent sets in the partition. This problem generalizes the square packing problem (in which we have ) and the graph coloring problem (in which s _i = 0 for all i = 1,2, . . . , sn). It is well known that coloring problems on general graphs are hard to approximate. Following previous work on the one-dimensional problem, we study the problem on specific graph classes, namely, bipartite graphs and perfect graphs. We design a -approximation for bipartite graphs, which is almost best possible (unless P = NP). For perfect graphs, we design a 3.2744-approximation. An extended abstract version of this paper has appeared in Proceedings of the 16th International Symposium on Fundamentals of Computation Theory (FCT 2007), pp 288–299. Rob van Stee was supported by the Alexander von Humboldt Foundation.     

Increasing the availability of FMS with multimedia-supported diagnostic expert systems

This paper summarizes some of the results in the field of diagnostic expert systems of the EUREKA MAINE EU 744 project FMSMAINT System. Methods and software have been developed to increase the lower-than-expected availability of expensive flexible manufacturing systems (FMS). In the work described in this paper a special emphasis has been put on efficiently integrating automatic data acquisition, data analysis supported by multimedia, and expert-system-based diagnostics. The software described has been installed in the industrial pilots participating in the project, and the modules have already also been taken to a commercial level.     

The Day-to-Day Co-Production of Ageing in Place

We report findings from a study that set out to explore the experience of older people living with assisted living technologies and care services. We find that successful ‘ageing in place’ is socially and collaboratively accomplished – ‘co-produced’ – day-to-day by the efforts of older people, and their formal and informal networks of carers (e.g. family, friends, neighbours). First, we reveal how ‘bricolage’ allows care recipients and family members to customise assisted living technologies to individual needs. We argue that making customisation easier through better design must be part of making assisted living technologies ‘work’. Second, we draw attention to the importance of formal and informal carers establishing and maintaining mutual awareness of the older person’s circumstances day-to-day so they can act in a concerted and coordinated way when problems arise. Unfortunately, neither the design of most current assisted living technologies, nor the ways care services are typically configured, acknowledges these realities of ageing in place. We conclude that rather than more ‘advanced’ technologies, the success of ageing in place programmes will depend on effortful alignments in the technical, organisational and social configuration of support.     

Semantic web technologies for video surveillance metadata

Video surveillance systems are growing in size and complexity. Such systems typically consist of integrated modules of different vendors to cope with the increasing demands on network and storage capacity, intelligent video analytics, picture quality, and enhanced visual interfaces. Within a surveillance system, relevant information (like technical details on the video sequences, or analysis results of the monitored environment) is described using metadata standards. However, different modules typically use different standards, resulting in metadata interoperability problems. In this paper, we introduce the application of Semantic Web Technologies to overcome such problems. We present a semantic, layered metadata model and integrate it within a video surveillance system. Besides dealing with the metadata interoperability problem, the advantages of using Semantic Web Technologies and the inherent rule support are shown. A practical use case scenario is presented to illustrate the benefits of our novel approach.