Improved Positioning Accuracy of the PA10-6CE Robot with Geometric and Flexibility Calibration

Accurate determination of robot geometric and flexibility parameters permits significant reduction of systematic errors and improved end-effector positioning accuracy. We apply a 30-parameter flexible geometric model to the Mitsubishi PA10-6CE robot and reduce mean/peak positional errors from 1.80/2.45 mm to 0.33/0.71 mm while loaded at 44 N.     

Fabrication of planar cobalt electrodes separated by a sub-10nm gap using high resolution electron beam lithography with negative PMMA

We present a fabrication process of cobalt nanoelectrodes compatible with spin-dependent transport measurements through a few or a single nano-object. It consists in etching a cobalt thin layer into pairs of planar nanoelectrodes separated by a nanometric gap using a negative Poly-MethylMethAcrylate (PMMA) mask patterned by high resolution electron beam lithography (HREBL). The irradiation parameters of 200keV HREBL on PMMA have been investigated using atomic force microscopy (AFM) to define accurately the PMMA transformation from positive to negative tone. The influence of the electron dose and the designed gap on the final gap between electrodes is presented. This complete study proves that PMMA can be used as a HREBL negative resist to fabricate nanoelectrodes separated by a controlled and reproducible gap ranging from 5nm to several tens of nanometers.     

Creating broadcast interactive drama in an NVE

By exploiting a networked virtual environment architecture, we produced the gaming part of an interactive television drama series, TypoToons. For decades TV show makers have been inventing tools and tricks to enhance the stories they tell. Equivalents of, and additions to these conventional tricks in interactive media can only mature an interactive television if multidisciplinary teams can obtain hands on experience of these newly emerging worlds. The production team for TypoToons and the interactively participating audience provided an excellent opportunity to develop such a team     

A Review of the Application of Meta-Heuristic Algorithms to 2D Strip Packing Problems

This paper is a review of the approachesdeveloped to solve 2D packing problems withmeta-heuristic algorithms. As packing tasks arecombinatorial problems with very large searchspaces, the recent literature encourages theuse of meta-heuristic search methods, inparticular genetic algorithms. The objective ofthis paper is to present and categorise thesolution approaches in the literature for 2Dregular and irregular strip packing problems.The focus is hereby on the analysis of themethods involving genetic algorithms. Anoverview of the methods applying othermeta-heuristic algorithms including simulatedannealing, tabu search, and artificial neuralnetworks is also given.     

Consumption-related development in microelectroforming

 High-aspect ratio microelectroforming is one of the most challenging techniques in MEMS microfabrication. This is particularly true with plating metal into the very tall micropatterned polymer molds made by X-ray lithography for primary or secondary metal structures or metal mold inserts within the framework of the LIGA process. Among various problems are: (1) the time consumption in plating very tall parts or using microelectroplating as a replication technique; (2) the cost of material, in particular in the formation of very high-aspect-ratio absorber structures for X-ray masks in the deep and ultra-deep X-ray lithography step. Received: 7 July 2000/Accepted: 23 August 2000     

A methodology for a Very Small Data Base design

This paper proposes a design methodology for very small databases for the purpose of being hosted by portable devices. Three main differences w.r.t. the traditional design methodologies are introduced: first, the main mobility issues are considered along with data distribution; second, context awareness is included in the data design issues to allow full exploitation of context-sensitive application functionalities; and third, the peculiarities of the storage device  (s$s$) are taken into account by introducing a logistic phase after the usual conceptual and logical phases. The three aspects together determine the VSDB ambient which is the set of personal and environmental characteristics determining the portion of data that must be stored on the portable device. This paper details the design methodology in its conceptual, logical and logistic phases.     

Musculoskeletal disorders among female and male air traffic controllers performing identical and demanding computer work

Operators with identical, demanding computer work (90 female and 97 male air traffic controllers) were found to have high prevalences of disorders (assessed by questionnaire and physical examination) in neck, shoulders and upper back. In spite of the identical work, the women displayed higher prevalences than the men (e.g. neck diagnoses 21% vs. 4%). Disorders in elbows, wrists and hands were less common, with similar rates in both genders. Generally, the psychosocial work environment (assessed by questionnaire) was found to be good, but with large inter-individual variation. Women experienced lower decision latitude than men, particularly regarding influence and freedom at work, but perceived higher social support. Physically, the work was characterized by relatively low angular velocities of upper arms (measured by inclinometry) and wrists (right: < 1 degrees/s during 19% of time, measuring by goniometry), dynamic muscular activities and high time fractions of rest in the trapezius and forearm extensor muscles (measuring by electromyography). There were only minor differences between the genders.     

Systems integration

The paper presents a view of systems integration, from an ergonomics/human factors perspective, emphasising the process of systems integration as is carried out by humans. The first section discusses some of the fundamental issues in systems integration, such as the significance of systems boundaries, systems lifecycle and systems entropy, issues arising from complexity, the implications of systems immortality, and so on. The next section outlines various generic processes for executing systems integration, to act as guides for practitioners. These address both the design of the system to be integrated and the preparation of the wider system in which the integration will occur. Then the next section outlines some of the human-specific issues that would need to be addressed in such processes; for example, indeterminacy and incompleteness, the prediction of human reliability, workload issues, extended situation awareness, and knowledge lifecycle management. For all of these, suggestions and further readings are proposed. Finally, the conclusions section reiterates in condensed form the major issues arising from the above.     

On the convergence rate of ordinal comparisons of random variables

The asymptotic exponential convergence rate of ordinal comparisons follows from well-known results in large deviations theory, where the critical condition is the existence of a finite moment generating function. In this note, we show that this is both a necessary and sufficient condition, and also show how one can recover the exponential convergence rate in cases where the moment generating function is not finite. In particular, by working with appropriately truncated versions of the original random variables, the exponential convergence rate can be recovered