A Posture Control Model and Balance Test for the Prediction of Relative Postural Stability

A balance testing methodology has been developed based on a posture control model which defines relative stability by the degree to which a transient postural perturbation causes the center-of-pressure on the feet to approach the limits of the base-of-support. To minimize anticipatory adaptations and to ensure subject safety, the balance test uses a small-amplitude continuous random or pseudo-random perturbation. The data are used to identify an input-output model, which is then used to predict large-amplitude transient response. Sixtyfour normal subjects were tested, as well as five patients with vestibular lesions and five elderly subjects with a history of falling. Tests were performed with eyes open (EO) and blindfolded (BF), and the EO/BF ratio was calculated. The results showed highly significant differences between young (20-40) and elderly (61-79) normals, but no differences between males and females. In using the balance test to identify the balance-impaired individuals, the BF and EO/BF data provided higher success rates than the EO data. Depending on the modeling method used, the balance test was able to identify up to three of five vestibular patients and five of five elderly fallers, at a false positive rate of 25 percent in the normal subjects.     

国际化学纤维大会庆祝40华诞

今年9月19- 21日在奥地利Dornbirn举办的第40届国际化学纤维大会把重点放在3个主题：汽车用纺织品、家用纺织品和运动服装。来自30个国家的750多位代表参加了本届会议。由于“9.11”恐怖事件，一些欧洲以外的代表取消了参加会议的计划。在大会的开幕式上，奥地利化学纤维研究所主任兼兰精公司的董事 Franz Raninger 博士发言。他说，2000年，化学纤维行业经历了兴旺的一年，增长了6 %。预计今年将继续增长。但是，信息技术泡沫的破灭，使我们回到现实中。美国经济停滞不前，欧洲和亚洲的生意已经滑坡，日本也已进入经济衰退时期，只有中国…     

An algorithm for the selection problem

A refinement to a well-known selection algorithm is described. The refinement results in a useful improvement in the performance of the original algorithm, particularly when the selection index is small relative to the median.     

2009显示周回顾：触控技术

在2009显示周上,触控技术取得了令人惊讶的突破,触控屏数目剧增,并且性能也得到提升。     

Adaptive HVAC zone modeling for sustainable buildings

Control of energy flows within a building is critical to achieving optimal performance of heating, ventilation and air-conditioning (HVAC) systems. To design optimal HVAC control strategies, a dynamic model of the HVAC system - particularly the building zones that it services - is essential. As analysis of building energy consumption is facilitated by the accurate prediction of indoor environmental conditions, techniques that dynamically model HVAC zones are crucial, and as such, is an active area of research. This paper focuses on real-time HVAC zone model fitting and prediction techniques based on physical principles, as well as the use of genetic algorithms for optimization. The proposed approach is validated by comparing real-time HVAC zone model fitting and prediction against the corresponding experimental measurements. In addition, comparison with prediction results using an algorithm based on feedback-delayed Kalman filters has demonstrated the superiority of the proposed approach in terms of prediction accuracy.     

STUDIES ON BARLEY AND MALT WITH THE RAPID VISCOANALYSER: [III] THE PREDICTION OF MALTING POTENTIAL FROM VISCOGRAMS

Examination of the relationships between extract and viscogram data of malts suggested the measurement of Time to Peak as a cultivar-independent measure of quality potential. This was tested against a large number of samples from the routine assessment programme. Both barleys and malts were examined. Some comparisons with the Falling Number Apparatus are reported. Prediction of malting potential from the differences between viscograms of barleys with and without added enzyme was also assessed. No measurement from the viscogram of barley was sufficiently accurate for predicting malting potential of a population of crossbreds from a breeding programme.     

Aquatic passive sampling of herbicides on naked particle loaded membranes: accelerated measurement and empirical estimation of kinetic parameters

Water-sampler equilibrium partitioning coefficients and aqueous boundary layer mass transfer coefficients for atrazine, diuron, hexazionone and fluometuron onto C18 and SDB-RPS Empore disk-based aquatic passive samplers have been determined experimentally under a laminar flow regime (Re = 5400). The method involved accelerating the time to equilibrium of the samplers by exposing them to three water concentrations, decreasing stepwise to 50% and then 25% of the original concentration. Assuming first-order Fickian kinetics across a rate-limiting aqueous boundary layer, both parameters are determined computationally by unconstrained nonlinear optimization. In addition, a method of estimation of mass transfer coefficients--therefore sampling rates--using the dimension-less Sherwood correlation developed for laminar flow over a flat plate is applied. For each of the herbicides, this correlation is validated to within 40% of the experimental data.The study demonstrates that for trace concentrations (sub 0.1 microg/L) and these flow conditions, a naked Empore disk performs well as an integrative sampler over short deployments (up to 7 days) for the range of polar herbicides investigated. The SDB-RPS disk allows a longer integrative period than the C18 disk due to its higher sorbent mass and/or its more polar sorbent chemistry. This work also suggests that for certain passive sampler designs, empirical estimation of sampling rates may be possible using correlations that have been available in the chemical engineering literature for some time.     

Relative potencies and combination effects of steroidal estrogens in fish

The natural steroids estradiol-17beta (E2) and estrone (E1) and the synthetic steroid ethynylestradiol-17alpha (EE2) have frequently been measured in waters receiving domestic effluents. All of these steroids bind to the estrogen receptor(s) and have been shown to elicit a range of estrogenic responses in fish at environmentally relevant concentrations. At present, however, no relative potency estimates have been derived for either the individual steroidal estrogens or their mixtures in vivo. In this study the estrogenic activity of E2, E1, and EE2, and the combination effects of a mixture of E2 and EE2 (equi-potent fixed-ratio mixture), were assessed using vitellogenin induction in a 14-day in vivo juvenile rainbow trout screening assay. Median effective concentrations, relative to E2, for induction of vitellogenin were determined from the concentration-response curves and the relative estrogenic potencies of each of the test chemicals calculated. Median effective concentrations were between 19 and 26 ng L(-1) for E2, 60 ng L(-1) for E1, and between 0.95 and 1.8 ng L(-1) for EE2, implying that EE2 was approximately 11 to 27 times more potent than E2, while E2 was 2.3 to 3.2 times more potent than E1. The median effective concentration, relative to E2, for the binary mixture of E2 and EE2 was 15 ng L(-1) (comprising 14.4 ng L(-1) E2 and 0.6 ng L(-1) EE2). Using the model of concentration addition it was shown that this activity of the binary mixture could be predicted from the activity of the individual chemicals. The ability of each individual steroid to contribute to the overall effect of a mixture, even at individual no-effect concentrations, combined with the high estrogenic potency of the steroids, particularly the synthetic steroid EE2, emphasizes the need to consider the total estrogenic load of these chemicals in our waterways.