Influence of age and proximity warning devices on collision avoidance in simulated driving

OBJECTIVE: We conducted a set of experiments to examine the utility of several different uni- and multimodal collision avoidance systems (CASs) on driving performance of young and older adult drivers in a high-fidelity simulator. BACKGROUND: Although previous research has examined the efficacy of different CASs on collision avoidance, there has been a dearth of studies that have examined such devices in different driving situations with different populations of drivers. METHOD: Several different CAS warnings were examined in varying traffic and collision configurations both without (Experiment 1a) and with (Experiment 2) a distracting in-vehicle task. RESULTS: Overall, collision avoidance performance for both potential forward and side object collisions was best for an auditory/visual CAS, which alerted drivers using both modalities. Interestingly, older drivers (60-82 years of age) benefited as much as younger drivers from the CAS, and sometimes they benefited more. CONCLUSION: These data suggest that CASs can be beneficial across a number of different driving scenarios, types of collisions, and driver populations. APPLICATION: These results have important implications for the design and implementation of CASs for different driver populations and driving conditions.     

A generalized Petri net modeling approach for the control of re-entrant flow semiconductor wafer fabrication

Re-entrant flow manufacturing lines, such as occur in semiconductor wafer fabrication, are characterized by a product routing that consists of multiple visits to a workstation or group of workstations during the manufacturing process. In this paper, a modeling approach is based on the use of generalized Petri nets for a re-entrant flow manufacturing line is presented. Specifically, three Petri net models representing a re-entrant flow line with three work centers and six machines are modeled. How these models may be used to represent a variety of queuing disciplines and work release policies is discussed.     

Hypoxic ventilatory responsiveness in Tibetan compared with Han residents of 3,658 m

Lifelong high-altitude residents of North and South America acquire blunted hypoxic ventilatory responses and exhibit decreased ventilation compared with acclimatized newcomers. The ventilatory characteristics of Himalayan high-altitude residents are of interest in the light of their reportedly lower hemoglobin levels and legendary exercise performance. Until recently, Sherpas have been the only Himalayan population available for study. To determine whether Tibetans exhibited levels of ventilation and hypoxic ventilatory drives that were as great as acclimatized newcomers, we compared 27 lifelong Tibetan residents of Lhasa, Tibet, China (3,658 m) with 30 acclimatized Han ("Chinese") newcomers matched for age, body size, and extent of exercise training. During room air breathing, minute ventilation was greater in the Tibetan than in the Han young men because of an increased respiratory frequency, but arterial O2 saturation and end-tidal PCO2 did not differ, indicating similar levels of effective alveolar ventilation. The Tibetan subjects had higher hypoxic ventilatory response shape parameter A values and hypercapnic ventilatory responsiveness than the Han subjects. Among the Han subjects, duration of high-altitude residence correlated with the degree of blunting of the hypoxic ventilatory drive. Paradoxically, hyperoxia (inspired O2 fraction 0.70) increased minute ventilation and decreased end-tidal PCO2 in the Tibetan but not in the Han men. We concluded that lifelong Tibetan residents of high altitude neither hypoventilated nor exhibited blunted hypoxic ventilatory responses compared with acclimatized Han newcomers, suggesting that the effects of lifelong high-altitude residence on ventilation and ventilatory response to hypoxia differ in Tibetan compared with other high-altitude populations.     

On the solution of an ill-posed design solidification problem using minimization techniques in finite- and infinite-dimensional function spaces

This paper provides a comparative study of two alternative methodologies for the solution of an inverse design solidification problem. It is the one-dimensional solidification problem of calculating the boundary heat flux history that achieves a desired freezing front velocity and desired heat fluxes at the freezing front. The front velocity h(t) and flux history q_mS(t) on the solid side of the front control the obtained cast structure. As such, the potential applications of the proposed methods to the control of casting processes are enormous. The first technique utilizes a finite-dimensional approximation of the unknown boundary heat flux function q₀(t). The second technique uses the adjoint method to calculate in L₂ the derivative of the cost functional, ‖T_m – T(h(t), t;q₀)‖, that expresses the square error between the calculated T(h(t), t; q₀) and the given freezing front temperature T_m. Both steepest descent (SDM) and conjugate gradient methods (CGM) are examined. A front tracking FEM technique is used for the discretization of the state space. A detailed numerical analysis of the space and time discretization of the ‘parameter’ and state spaces, of the effect of the end condition of the adjoint problem and of other parameters in the solution are examined.     

Discrimination or favoritism? Sex bias in book reviews.

Studied 180 reviews of books written by male, female, or male and female authors to investigate sex bias. Half the books had been reviewed by males, half by females. Each review was rated separately for positive and negative elements. For positive elements, there was a significant interaction between author's and reviewer's sex: same-sex books were more favorably evaluated than other-sex books, while books of mixed authorship fell in between. There was no comparable interaction for negative elements. Reviewers of both sexes tended to find more negative elements in books by male than by female authors. It is concluded that unlike in studies employing hypothetical situations, in real-life settings each sex is biased in favor of itself. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automation of palm oil mills

Automation is the function of monitoring and regulating process operations non-manually or remotely to check or maintain the required processing conditions and product quality, the use of instrumental techniques of analysis in the laboratory and the use of computers for data processing and other miscellaneous applications. Applications where automation is justifiable and the impact of changing trends in automation technology, especially the recent influx of microprocessor-based systems, are discussed briefly. Applications in the palm oil mill where automation is fairly well-developed and is being developed, as well as ideas for future applications are reviewed. An example of a practical approach to automation in palm oil mills is given using automatic control of crude oil dilution.     

Determinants of temperature in small coastal embayments of Lake Ontario

Along 25 km of the Lake Ontario shoreline near Toronto, Ontario, small coastal embayments (0.4–32 ha) have been constructed or modified by lake-infilling to restore warmwater fish habitat. The variation in thermal habitat quality for warmwater fishes among these embayments is very high; temperatures range from those found within a small pond to those of much cooler Lake Ontario. Since meteorological conditions and surface heat fluxes are almost identical, the temperature variation among embayments must be caused by differences in bathymetry or exchange with Lake Ontario. However, a previous study on these embayments found paradoxically that temperatures were not strongly associated with channel size or embayment bathymetry. This paper resolves the paradox by showing that flushing times for almost all of the constructed embayments were less than 1 day, and often less than 12 h. With so little time to warm within the embayments, water temperatures of almost all embayments remained very close to the temperatures of the adjacent lake waters. The coldest embayments connected directly to open Lake Ontario and warmer embayments connected to Lake Ontario through other embayments or protected harbors, where the inflowing water from Lake Ontario had already substantially warmed. To allow embayments along the exposed shoreline of Toronto to reach acceptable temperatures for warmwater fish, we use heat budgets to calculate that average summer flushing times must be increased from their current length of 1.5 to 5.5 h to approximately 30 h. Such changes could be achieved through large reductions in the channel cross section.     

The history and development of the helium ion microscope

The helium ion microscope has recently emerged as a commercially available instrument. However, its roots go back more than 60 years to the development of the field ion microscope in Berlin, first reported in 1951. Over the intervening years, numerous researchers have pursued the development of a gas field ionization source with the goal of producing a suitable source for an ion microscope. This proved to be an elusive goal until early in this century when a number of discoveries led to a successful source, and shortly thereafter, an instrument fully able to exploit its advantages. Many individuals and many technical advances have come together to make this new class of microscope. The long history of this quest is reviewed along with the recent advances that led to the achievement of this milestone. A brief summary of the current status of the technology and its applications are given.     

Population shift bias in tests of space–time interaction

Common to all tests of space–time interaction is the assumption that the population underlying the events of interest exhibits a trajectory of growth that is consistent through time and across space. In practice, however, this assumption is often untenable and, when violated, can introduce population shift bias into the results of these tests. While this problem is widely recognized, more work remains to compare its effect across tests and to determine the extent to which it is a problem for study short periods. This paper quantifies and compares the population shift bias present in the results of the Knox, Mantel, and Jacquez tests of space–time interaction. A simulation study is carried out which quantifies the bias present in each test across a variety of population movement scenarios. Results show a positive relationship between population shift bias and the heterogeneity in population growth across all the tests. They also demonstrate variability in the size of the bias across the three tests for space–time interaction considered. Finally, the results illustrate that population shift bias can be a serious problem for short study periods. Collectively, these findings suggest that an unbiased approach to assessing the significance of space–time interaction test results is needed whenever spatially heterogeneous population change is identified within a study area.