The tree cut and merge algorithm for estimation of network reliability

This article presents Monte Carlo techniques for estimating network reliability. For highly reliable networks, techniques based on graph evolution models provide very good performance. However, they are known to have significant simulation cost. An existing hybrid scheme (based on partitioning the time space) is available to speed up the simulations; however, there are difficulties with optimizing the important parameter associated with this scheme. To overcome these difficulties, a new hybrid scheme (based on partitioning the edge set) is proposed in this article. The proposed scheme shows orders of magnitude improvement of performance over the existing techniques in certain classes of network. It also provides reliability bounds with little overhead.

Tool support for testing concurrent Java components

Concurrent programs are hard to test due to the inherent nondeterminism. This paper presents a method and tool support for testing concurrent Java components. Too[ support is offered through ConAn (Concurrency Analyser), a too] for generating drivers for unit testing Java classes that are used in a multithreaded context. To obtain adequate controllability over the interactions between Java threads, the generated driver contains threads that are synchronized by a clock. The driver automatically executes the calls in the test sequence in the prescribed order and compares the outputs against the expected outputs specified in the test sequence. The method and tool are illustrated in detail on an asymmetric producer-consumer monitor. Their application to testing over 20 concurrent components, a number of which are sourced from industry and were found to contain faults, is presented and discussed.

The reliability of video based time motion analysis

Time motion analysis is extensively used to assess the demands of team sports. At present there is only limited information on the reliability of measurements using this analysis tool. The aim of this study was to establish the reliability of an individual observer's time motion analysis of rugby union. Ten elite level rugby players were individually tracked in Southern Hemisphere Super 12 matches using a digital video camera. The video footage was subsequently analysed by a single researcher on two occasions one month apart. The test-retest reliability was quantified as the typical error of measurement (TEM) and rated as either good (10% TEM). The total time spent in the individual movements of walking, jogging, striding, sprinting, static exertion and being stationary had moderate to poor reliability (5.8-11.1% TEM). The frequency of individual movements had good to poor reliability (4.3-13.6% TEM), while the mean duration of individual movements had moderate reliability (7.1-9.3% TEM). For the individual observer in the present investigation, time motion analysis was shown to be moderately reliable as an evaluation tool for examining the movement patterns of players in competitive rugby. These reliability values should be considered when assessing the movement patterns of rugby players within competition.

Reliability of scores between stroke patients and significant others on the Reintegration to Normal Living (RNL) Index

Purpose: This study measured reliability between stroke patients' and significant others' scores on items on the Reintegration to Normal Living (RNL) Index and whether there were any scoring biases. Method The 11-item RNL Index was administered to 57 pairs of patients and significants six months after stroke rehabilitation. The index was scored using a 10-point visual analogue scale. Patient and significant other demographic information and data on patients' clinical, functional and cognitive status were collected. Reliability was measured using the intra-class correlation coefficient (ICC) and percent agreement. Results: Overall poor reliability was found for the RNL Index total score (ICC=.36, 95% CI. 07 to .59) and the daily functioning subscale (ICC=.24, 95% CI -.003 to .46) and moderate reliability was found for the perception of self subscale (ICC=.55, 95 % CI .28 to .73). There was a moderate bias for patients to rate themselves as achieving better reintegration than was indicated by significant others, although no demographic or clinical factors were associated with this bias. Exact match agreement was best for the subjective items and worse for items reflecting mobility around the community and participation in a work activity. Conclusions: Caution is needed when interpreting patient information reported by significant others on the RNL Index. The use of a shorter scale to rate the RNL Index requires investigation.

In situ characterization of stickiness of sugar-rich foods using a linear actuator driven stickiness testing device

A stickiness testing device based on the probe tack test has been designed and tested. It was used to perform in situ characterization of drying hemispherical drops with an initial radius 3.5 mm. Tests were carried out in two drying temperatures, 63 and 95 degreesC. Moisture and temperature histories of the drying drops of fructose, honey, sucrose, maltodextrin and sucrose-maltodextrin mixtures were determined. The rates of moisture evaporation of the fructose solution was the fastest while those of the maltodextrin solution was the lowest. A profile reversal was observed when the temperature profiles of these materials were compared. Different modes of failure were observed during the stickiness tests. Pure fructose and honey solutions remained completely sticky and failed cohesively until the end of drying. Pure sucrose solution remained sticky and failed cohesively until complete crystallization occurred. The surface of the maltodextrin drops formed a skin shortly after the start of drying. It exhibited adhesive failure and reached a state of non-adhesion. Addition of maltodextrin significantly altered the stickiness of sucrose solution. (C) 2002 Elsevier Science Ltd. All rights reserved.

Reliability of moderate-intensity and vigorous physical activity stage of change measures for young adults

Background. The purpose of this study was to examine the reliability of stage of change (SOC) measures for moderate-intensity and vigorous physical activity in two separate samples of young adults. Staging measures have focused on vigorous exercise, but current public health guidelines emphasize moderate-intensity activity. Method. For college students in the USA (n = 105) and in Australia (n = 123), SOC was assessed separately on two occasions for moderate-intensity activity and for vigorous activity. Test-retest repeatability was determined, using Cohen's kappa coefficient. Results. In both samples, the reliability scores for the moderate-intensity physical activity staging measure were lower than the scores for the vigorous exercise staging measure. Weighted kappa values for the moderate-intensity staging measure were in the fair to good range for both studies (0.50 and 0.45); for the vigorous staging measure kappa values were excellent and fair to good (0.76 and 0.72). Conclusions. There is a need to standardize and improve methods for staging moderate-intensity activity, given that such measures are used in public health interventions targeting HEPA (health-enhancing physical activity). (C) 2003 American Health Foundation and Elsevier Science (USA). All rights reserved.

Tympanometry and TEOAE testing of children with Down Syndrome in Special Schools

Despite widespread awareness that children with Down syndrome are particularly susceptible to hearing pathologies, the audiological status of students with Down syndrome in special schools is all too often unknown. Unfortunately, hearing screening for this population is unable to rely on standard, behavioural test batteries. To facilitate future improvements in screening protocols, this study investigated the results of tympanometry and transient evoked otoacoustic emission (TEOAE) testing for a group of children with Down syndrome. Assessments were not conducted in the artificial context of a clinic or laboratory, but within the school environment. Outcomes are reported for 27 subjects with a mean age of 10 years 5 months (SD = 4;11). Tympanometry testing was failed in at least one ear by 41.7% of subjects, while a failure rate of 81.5% of subjects was observed for TEOAE testing. Therefore, it is concluded that immediate review of hearing screening programs for students with Down syndrome is highly advisable.