Lost in virtual space: Studies in human and ideal spatial navigation.

The authors describe 3 human spatial navigation experiments that investigate how limitations of perception, memory, uncertainty, and decision strategy affect human spatial navigation performance. To better understand the effect of these variables on human navigation performance, the authors developed an ideal-navigator model for indoor navigation whose optimizing algorithm uses a partially observable Markov decision process. The model minimizes the number of actions (translations and rotations) required to move from an unknown starting state to a specific goal state in indoor environments that have perceptual ambiguity. The authors compared the model's performance with that of the human observer to measure human navigation efficiency. Experiment 1 investigated the effect of increasing the layout size on spatial way-finding efficiency and found that participants' efficiencies decreased as layout size increased. The authors investigated whether this reduction in navigation efficiency was due to visual perception (Experiment 2), memory, spatial updating strategy, or decision strategy (Experiment 3). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An overview of JML tools and applications

The Java Modeling Language (JML) can be used to specify the detailed design of Java classes and interfaces by adding annotations to Java source files. The aim of JML is to provide a specification language that is easy to use for Java programmers and that is supported by a wide range of tools for specification typechecking, runtime debugging, static analysis, and verification.This paper gives an overview of the main ideas behind JML, details about JML’s wide range of tools, and a glimpse into existing applications of JML.     

Making XML document markup international

In name and in practice, the World‐Wide Web (hereafter Web) is used around the World beyond English‐speaking areas. This creates a tremendous need to internationalize standard terminology used in the technologies that make the Web possible. Existing efforts on XML internationalization (i18n) and localization (i10n) have focused on the content of XML documents instead of the terms used in markup (annotations) such as elements and attributes. The SGML standard ISO 8879 supports the use of Unicode (ISO 10646) throughout a document, including markups. However, most elements and attributes of XML documents are still defined in English, thereby limiting their use among non‐English speakers. This paper presents an XSLT‐based method that can completely localize the markup of XML documents into different natural languages. We also describe how the proposed technique can be applied to translation problems in programming (e.g. C and Java) or documentation (e.g. LAT_EX or other formatting languages) so that a program or a document can be converted to and from an XML format. Copyright © 2004 John Wiley & Sons, Ltd.     

Fragment shaders for agent animation using finite state machines

In a previous paper we generated animated agents and their behavior using a combination of XML and images. The behavior of agents was specified as a finite state machine (FSM) in XML. We used images to determine properties of the world that agents react to. While this approach is very flexible, it can be made much faster by using the power available in modern GPUs. In this paper we implement FSMs as fragment shaders using three kinds of images: world space images, agent space images and FSM table images. We show a simple example and compare performance of CPU and GPU implementations. Then we examine a more complex example involving more maps and two types of agents (predator–prey). Furthermore we explore how to render agents in 3D more efficiently by using a variation on pseudoinstancing.     

真空灭弧室 配电开关 断路器和接触器的高可靠性元件

自从20世纪50年代中期将真空灭弧室(VI)用作配电操作开关、断路器和接触器的电流分断元件以来,其作用逐步增强.在电路的开断和配电保护领域,该电气产品已经占统治地位.真空灭弧室甚至被引入到电力输送中的通断产品的领域上.真空灭弧室受到追捧的原因有:结构紧凑、适用范围广、成本低、极好的电寿命和机械寿命,以及使用方便.其中,最重要的优点是公认的高可靠性.     

Inverse Routh table construction and stability of delay equations

Based on an inversion of the Routh table construction, a unimodular characterization of all Hurwitz polynomials is obtained. In parameter space, the Hurwitz polynomials of degree n correspond to the positive 2ⁿ-tant. The method is then used to construct classes of stable continuous-time delay-difference equations and delay differential equations of neutral type, by a suitable limiting process.     

A Chip for an Implantable Neural Stimulator

This paper describes a chip for a multichannel neural stimulator for functional electrical stimulation (FES). The purpose of FES is to restore muscular control in disabled patients. The chip performs all the signal processing required in an implanted neural stimulator. The power and digital data transmission to the stimulator passes through a 5 MHz inductive link. From the signals transmitted to the stimulator, the chip is able to generate charge-balanced current pulses with a controllable length up to 256 s and an amplitude up to 2 mA, for stimulation of nerve fibers. The quiescent current consumption of the chip is approx. 650 A at supply voltages of 6–12 V, and its size is 3.9×3.5 mm². It has 4 output channels for use in a multipolar cuff electrode.     

An Early Use of Continuations and Partial Evaluation for Compiling Rules Written in First-Order Predicate Calculus

This brief historical note describes research done in the period 1970-1973, and where continuations were introduced in a fairly pragmatic way together with partial evaluation in order to compile rules expressed as statements in first-order predicate calculus. Although the methods used at that time were quite straightforward, this work may shed some light on the early history of the concept of continuations. In particular, unlike other early contributions that addressed issues in mainstream programming languages, the present approach initially addressed implementation techniques for special-purpose languages.     

Die Kapazität einer einlagigen Spule mit Berücksichtigung der Drahtstärke und des Windungsabstandes

Zusammenfassung Die Kapazität einer Spule wird folgendermaßen definiert: Die Frequenz eines Schwingungskreises, der aus der Spule und einem äußeren variablen Kondensator besteht, ist eine transzendente Funktion der Kondensatorkapazität mit unendlich vielen Zweigen — der Grundfrequenz und den Oberfrequenzen. Die transzendente Kurve der Grundfrequenz fällt asymptotisch mit der algebraischen Kurve der Thomsonschen Formel zusammen, wenn darin zur Kondensatorkapazität eine gewisse Konstante die Spulenkapazität addiert wird. Zahlentafel 1 zeigt, daß die beiden Kurven fast vollständig bis der freischwingenden Spule herab (verschwindenden Kondensatorkapazität) zusammenfallen. Als theoretischen Wert der Spulenkapazität findet Verfasser für eine einlagige Spule ohne Kern 1,111 (+/2n) R F, wo R der Spulenradius in cm,n die Windungszahl der Spule, und angegebene Funktionen der Spulenform sind und eine Funktion der Ganghöhe und der Dielektrizitätskonstante der Drahtisolation ist.     

LISREL: an Alternative to MANOVA and Principal Components in Designed Experiments when the Response is Multidimensional

In designed industrial experiments, the response is often multidimensional. There may be different responses and/or responses of equal kind that are correlated. The usual analysis is by a separate ANOVA (Analysis of Variance) for each response or by MANOVA (Multivariate Analysis of Variance) of all responses simultaneously. However, ANOVA/MANOVA techniques do not fully address the multivariate situation. In this paper, MANOVA, principal components analysis, and LISREL (Linear Structural Relationship), are applied to the results of an experiment concerning high‐precision breathing apparatus to be used by firefighters. The experimental design is a 2^5?1_V, having seven response measurements and five replicates. We address both establishing a cause–effect relation, and the estimation of the impact size. The multivariate techniques strongly reduce the number of tests to be performed. MANOVA and LISREL provide standard errors of every parameter of interest. The LISREL model is very flexible in model building and parameter testing, and it gives enhanced insight into the experimental results. Its use in industrial experiments has not been fully exploited; one possible explanation is that such experiments often have too few runs. Copyright © 2005 John Wiley & Sons, Ltd.