Computation of steady and time-dependent temperature distribution for building elements: A general three-dimensional solution

A computational method of temperature distribution calculation for building elements in two- and three-dimensional time-dependent heat flow problems is developed with a general approximate solution using, as a numerical approach, the finite difference method. An analytical evaluation method of the accuracy of calculations is developed. The method described was compared with experimental values and good correspondence was obtained. The time-dependent study which is presented includes thermal resistance and inertia (heat capacity) of the components' materials and different geometric compositions.     

A system for in-vivo cardiac optical mapping

Optical mapping of cardiac electrical activity is a valuable technique for studying arrhythmias, particularly the effects of defibrillation shocks. This technique has been exclusively applied to in-vitro preparations of hearts or tissues removed from an animal. But verification of experimental results and hypotheses is ideally performed in vivo on the heart as it remains in place in the animal. However, in-vitro optical mapping instrumentation and techniques cannot be easily applied in vivo. This article describes a system the authors developed to address this problem     

Bruising on ostrich carcasses and the implications on the microbiology and losses in utilizable meat when removing them post-evisceration or post-chilling

Bruising on ostrich carcasses reduces meat yield. These bruises are usually removed as part of the primary meat inspection, performed directly after evisceration. Three separate studies were conducted to determine the advantages and disadvantages of removing the bruises at primary meat inspection or after overnight cooling of the ostrich carcasses (0–4 °C). The bruised areas were also investigated to determine their frequency and distribution and to establish the most obvious causes and possible preventative measures. The neck bruises represented 52.58% of all bruises; the high side railings of the transport vehicles being the most probable cause. Large and multiple bruising were probably from the trampling of birds lying down. It was established that trimming bruises on warm carcasses caused higher total aerobic viable counts on the trimmed surfaces than cold trimming. Cold trimming together with better management of trimming practices also led to a decrease in meat yield losses.     

Improved Rover State Estimation in Challenging Terrain

Given ambitious mission objectives and long delay times between command-uplink/data-downlink sessions, increased autonomy is required for planetary rovers. Specifically, NASA's planned 2003 and 2005 Mars rover missions must incorporate increased autonomy if their desired mission goals are to be realized. Increased autonomy, including autonomous path planning and navigation to user designated goals, relies on good quality estimates of the rover's state, e.g., its position and orientation relative to some initial reference frame. The challenging terrain over which the rover will necessarily traverse tends to seriously degrade a dead-reckoned state estimate, given severe wheel slip and/or interaction with obstacles. In this paper, we present the implementation of a complete rover navigation system. First, the system is able to adaptively construct semi-sparse terrain maps based on the current ground texture and distances to possible nearby obstacles. Second, the rover is able to match successively constructed terrain maps to obtain a vision-based state estimate which can then be fused with wheel odometry to obtain a much improved state estimate. Finally the rover makes use of this state estimate to perform autonomous real-time path planning and navigation to user designated goals. Reactive obstacle avoidance is also implemented for roaming in an environment in the absence of a user designated goal. The system is demonstrated in soft soil and relatively dense rock fields, achieving state estimates that are significantly improved with respect to dead reckoning alone (e.g., 0.38 m mean absolute error vs. 1.34 m), and successfully navigating in multiple trials to user designated goals.     

Exploring a national cybersecurity exercise for universities

In cybersecurity competitions, participants either create new or protect preconfigured information systems and then defend these systems against attack in a real-world setting. Institutions should consider important structural and resource-related issues before establishing such a competition. Critical infrastructures increasingly rely on information systems and on the Internet to provide connectivity between systems. Maintaining and protecting these systems requires an education in information warfare that doesn't merely theorize and describe such concepts. A hands-on, active learning experience lets students apply theoretical concepts in a physical environment. Craig Kaucher and John Saunders found that even for management-oriented graduate courses in information assurance, such an experience enhances the students' understanding of theoretical concepts. Cybersecurity exercises aim to provide this experience in a challenging and competitive environment. Many educational institutions use and implement these exercises as part of their computer science curriculum, and some are organizing competitions with commercial partners as capstone exercises, ad hoc hack-a-thons, and scenario-driven, multiday, defense-only competitions. Participants have exhibited much enthusiasm for these exercises, from the DEFCON capture-the-flag exercise to the US Military Academy's Cyber Defense Exercise (CDX). In February 2004, the US National Science Foundation sponsored the Cyber Security Exercise Workshop aimed at harnessing this enthusiasm and interest. The educators, students, and government and industry representatives attending the workshop discussed the feasibility and desirability of establishing regular cybersecurity exercises for postsecondary-level students. This article summarizes the workshop report.     

The Tech Buzz Game [stock market prediction]

Prediction markets, also known as information or decision markets, are designed to forecast future events or trends. Internet-based prediction markets can easily aggregate the insights of an unlimited number of potentially knowledgeable people asynchronously. The Tech Buzz Game - a joint venture between Yahoo! Research Labs and O'Reilly Media - is a fantasy prediction market launched in March 2005 at the O'Reilly Emerging Technology (ETech) Conference. The game consists of multiple sub-markets that pit a handful of rival technologies, each represented by a stock, against one another. The game's object is to anticipate future search buzz and buy and sell stocks accordingly. Thus, a player who believes BitTorrent stock is undervalued might buy shares, while a player who thinks BitTorrent is overpriced might sell the stock or instead purchase shares in a competing peer-to-peer technology. The Tech Buzz Game serves two key research-oriented goals. One is to evaluate the power of prediction markets to forecast high-tech trends. The other goal of the Tech Buzz Game is to field test the dynamic pari-mutuel market, a Yahoo! Research Labs trading mechanism designed to price and allocate shares.     

Not just another self-consistent magnetic recording model

A self-consistent magnetic recording modeling method is presented which has proven useful in recording channel design on thin media. Improvements in the magnetic model and in the mathematical treatment stabilize the iterative process and reduce computer storage requirements. Major and minor media loops are fitted to quickly computable bipolynomials. Mathematical improvements include using a strong band diagonal demagnetization matrix, analytic integration with quadratic magnetization fitting, and Newton-Raphson iteration, which gives rapid convergence without underrelaxation. Quantitative predictions of timing errors in 16-bit modified frequency modulation (MFM) data patterns on a 350-bit/mm, 20-track/mm disk memory are presented, as well as playback amplitudes and saturation currents. Predictions can also be compared with experimental read/write data to determine system parameters. Two examples are given: the inference of the head efficiency and of the effective high-frequency medium squareness.     

Commonality and variability in software engineering

The article describes how to perform domain engineering by identifying the commonalities and variabilities within a family of products. Through interesting examples dealing with reuse libraries, design patterns, and programming language design, the authors suggest a systematic scope, commonalities, and variabilities approach to formal analysis. Their SCV analysis has been an integral part of the FAST (Family-oriented Abstraction, Specification, and Translation) technology applied to over 25 domains at Lucent Technologies