Driver workload during differing driving maneuvers

Motorcycle-automobile accidents occur predominantly when the car driver turns left across the motorcyclist's right-of-way. Efforts to decrease this specific collision configuration, through an increase in motorcycle conspicuity, have concentrated on the physical characteristics of the motorcycle and its rider. The work reported here examines the behavior of car drivers during different driving sequences, in particular during left-turn maneuvers. An experiment is reported that used simultaneous video-taping of the driver and the forward-looking scene. Subjects followed a preset on-road course and were observed for head movements to determine the possibility of structural interference eye-blink frequency, probe-response time, and probe response error, as measures of cognitive or mental workload. In addition, the subjects completed two major subjective workload evaluations as reflections of effort directed to different components of the driving task. Results indicated that there were significant increases in head movements and mental workload during turn sequences compared to straight driving. This result of higher driver workload may be responsible for increasing the potential for detection failure. Such a propensity is also fostered by the higher structural interference that may be expected during turns. Failures to observe during turning sequences have differing outcomes depending on the presence of opposing traffic, as during the left turn, compared with the absence of such opposition, as occurs in the right turn. Also, the less conspicuous the oncoming vehicle in the left turn scenario, the higher the probability of detection failure. At the present time the least conspicuous powered vehicle is the motorcycle.     

Laboratory investigation of an amplitude comparator baseddirectional comparison digital protection scheme

A directional comparison digital protection scheme has been implemented with a 16-b single-board computer at each end of a physical model of a transmission line, with communication between the two ends. The protection algorithm makes use of the fundamental frequency components of the deviation signals of the voltage and phase-shifted current. Software routines have been developed for fault monitoring, directional determination, and the trip/block decision. Graphics features incorporated in the software are explained. Tests for various faults conducted on the physical model of a double-circuit transmission line show that the direction to a fault is determined in 3 to 7 ms. The blocking features of the relay are demonstrated     

Implementation and experimental studies of an adaptive self-optimizing power system stabilizer

This paper describes the implementation and experimental studies of an adaptive self-optimizing pole shifting power system stabilizer. Using an Intel iSBC386/21 single-board computer, the adaptive power system stabilizer has been tested on a physical model of a single-machine infinite-bus power system. Under different operating conditions and disturbances, the behavior of the proposed adaptive stabilizer was investigated. Comparison has also been made to a digital-type conventional fixed-parameter power system stabilizer. Results of the experimental studies show that the proposed adaptive stabilizer outperforms the conventional stabilizer.     

Buckling of thin flat-walled structures by a spline finite strip method

A method of buckling analysis of thin flat-walled structures of finite length subjected to longitudinal compression and bending, transverse compression as well as shear is described. The analysis uses the spline finite strip method and allows for boundary conditions other than simply supported ends as required in the semi-analytical finite strip method of buckling analysis.Convergence studies with increasing numbers of section knots are described for plates in compression, bending and shear, and for long columns with different support conditions subjected to compression. A buckling analysis of a stiffened plate subjected to compression and shear is compared with results from a finite element analysis.     

Effect of prepartum selenium treatment on uterine involution in the dairy cow

Selenium injections and oral vitamin E supplementation prepartum were related to: postpartum uterine involution (decrease in uterine size per unit time) and days to minimum uterine size in a 2 X 2 factorial design. Complete data were analyzed from 64 cows. Groups were selenium plus vitamin E, vitamin E, selenium, and control. Factors significantly affecting uterine size between 14 and 50 d postpartum were cow weight, days postpartum-linear, days postpartum-quadratic, day X metritis, and day X metritis X selenium treatment. Days to minimum uterine size were significantly less in cows with metritis and selenium treated when compared with cows with metritis and not selenium treated (32.9 vs. 35.8).     

Short communication: The effect of centrifugation and resuspension on the recovery of Mycoplasma species from milk

Low sensitivity of a single bulk tank milk culture is a major limitation for detection of mycoplasma organisms. We hypothesized that sedimentation of Mycoplasma spp. in a milk sample by centrifugation followed by resuspension in a small volume of fluid before agar plating would increase the ability to detect Mycoplasma spp. compared with direct conventional culture. The experiment was conducted to determine recovery of Mycoplasma spp. from milk as affected by 1) treatment (centrifugation vs. conventional method); 2) 2 species (Mycoplasma bovis and Mycoplasma californicum and 4 strains for each species); and 3) 4 different concentrations of Mycoplasma spp. (1,000, 100, 10, and 1 cfu/mL). A 5-mL portion of mycoplasma suspension from each strain was inoculated into 45 mL of fresh bulk tank milk to achieve concentrations of 1,000, 100, 10, and 1 cfu/mL. Treatment samples were vigorously mixed and centrifuged at 5,000 × g for 30 min. Control samples were vigorously mixed. All samples were plated on modified Hayflick agar. Plates were incubated at 37°C and 5% CO₂ for 5 d. Mean (±SE) log₁₀ mycoplasma counts (cfu/mL) in the treatment groups (1.91 ± 0.15) were higher than those in the control groups (1.70 ± 0.16). Recovery of at least 1 mycoplasma colony on agar culture was 100% in both treatment and control groups at high, medium, and low concentrations. At the lowest concentration, recovery of at least 1 mycoplasma colony on agar culture in treatment and control groups was 75% (n = 12/16) and 18.75% (n = 3/16), respectively. Centrifugation of milk followed by suspension in a smaller volume of saline before conventional culture increased the ability to detect mycoplasma microorganisms in the milk sample compared with controls. Recovery by centrifugation appeared best at the lowest concentration where detection of a positive sample was 4 times more likely than when conventional methods were used.     

The control of VTEC in the animal reservoir.

A great diversity of VTECs exist but only in the case of Escherichia coli O157:H7, a common human foodborne pathogen, has sufficient research been done to allow generalizations about the ecology. The key features are as follows: lack of host specificity such that indistinguishable isolates can be found in a variety of species; near-ubiquitous distribution in cattle (and perhaps other ruminant) farms; transient residence in the gastrointestinal flora of individual animals that is not associated with clinical disease; temporal clustering at the population level such that most fecal shedding is confined to sharp bursts in a high percentage of animals separated by much longer periods of very low prevalence; a higher prevalence in young animals in comparison to older ones: a higher prevalence in animals with floral disturbance such as that caused by transit, feed changes or antimicrobial dosing; and a markedly higher prevalence during warm months. Molecular epidemiological studies of E. coli O157:H7 have demonstrated that subtypes of the organism can persist on cattle farms for years, thus supporting a conclusion that cattle farms represent a reservoir. Yet on such farms, common subtypes are often found in environmental niches and in other species of animals; thus, it is not completely clear that cattle themselves are the reservoir. New subtypes are periodically observed on particular farms, and indistinguishable subtypes can be found on farms that are separated by hundreds of kilometers even in the absence of any obvious animal movements between them. The number of subtypes found on a farm does not appear to be qualitatively correlated with cattle movements (e.g., purchases) into the farm. Commercial feeds are sometimes contaminated with E. coli O157:H7, and it seems likely that feeds represent an important route of dissemination for this agent and other VTEC. Mixed feeds collected from feeding troughs are commonly positive for E. coli O157:H7, as are cattle watering troughs, and feed and water likely represent the most common means of infection. Environmental replication in feeds and in sediments of watering troughs occurs and may account for the higher level of fecal shedding in the warm months. Since E. coli O157:H7 has been found to persist and remain infective for at least 6 months in water trough sediments, this may be an important environmental niche where the organism survives during periods when it cannot be detected in cattle, especially during cold months. Traditional means of controlling infectious agents, such as eradication or test and removal of carrier animals, do not appear to be feasible for VTECs. Nevertheless, certain farm management practices-especially those related to maintenance and multiplication of the agent in feed and water-may provide practical means to substantially reduce the prevalence of these agents in cattle on farms and in those arriving at slaughter plants.     

High-order graph matching kernel for early carcinoma EUS image classification

Endoscopic ultrasonography (EUS) is limited by variability in the examiner’s subjective interpretation to differentiate between normal, leiomyoma of esophagus and early esophageal carcinoma. By using information otherwise discarded by conventional EUS systems, quantitative spectral analysis of the raw pixels (picture elements) underlying EUS image enables lesions to be characterized more objectively. In this paper, we propose to represent texture features of early esophageal carcinoma in EUS images as a graph by expressing pixels as nodes and similarity between the gray-level or local features of the EUS image as edges. Then, similarity measurements such as a high-order graph matching kernel can be constructed so as to provide an objective quantification of the properties of the texture features of early esophageal carcinoma in EUS images. This is in terms of the topology and connectivity of the analyzed graphs. Because such properties are directly related to the structure of early esophageal carcinoma lesions in EUS images, they can be used as features for characterizing and classifying early esophageal carcinoma. Finally, we use a refined SVM model based on the new high-order graph matching kernel, resulting an optimal prediction of the types of esophageal lesions. A 10-fold cross validation strategy is employed to evaluate the classification performance. After multiple computer runs of the new kernel SVM model, the overall accuracy for the diagnosis between normal, leiomyoma of esophagus and early esophageal carcinoma was 93 %. Moreover, for the diagnosis of early esophageal carcinoma, the average accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 89.4 %, 94 %, 95 %, 89 %, and 97 % respectively. The area under all the three ROC curves were close to 1.     

Planners in The Changing American City, 1900-1940

Originating in the 1900's as part of the nation's reaction to generations of disruptive growth and change, the American planning profession pioneered socially enhancing ideals of comprehensive physical reorganization which were widely accepted by 1940 and inform planning's basic alignment with urban policy today. Its weaving of new fabrics through old cities was barely begun, however, and it was subliminated to pressures unalterable by planners alone, and required substantial further allocation of resources joined to new techniques for expanding commonality and individuality in the changing city.     

Inelastic buckling analyses of beams, columns and plates using the spline finite strip method

A method of inelastic buckling analysis of thin-walled structural members and plates is described. The method is based on the spline finite strip method of structural analysis. The analysis takes into account the non-linear material stress-strain properties, strain hardening and residual stresses. The plastic theories used in the study are the flow theory of plasticity and the deformation theory of plasticity. The method of inelastic buckling analysis is applied to a variety of instability problems including plates, cold-formed columns, hot-rolled columns and welded tee section beams. The buckling modes and loads computed are compared with theoretical values and test results.