A 24-m3 direct heat-sink calorimeter with on-line data acquisition, processing, and control

1985 ◽  
Vol 249 (4) ◽  
pp. E416-E432 ◽  
Author(s):  
S. Jacobsen ◽  
O. Johansen ◽  
L. Garby

The construction and performance of a 24-m3 direct heat-sink calorimeter for continuous measurement of evaporative and sensible heat loss in human subjects are described. Extensive use of real-time processing for compensation of physical time constants and delays made it possible to solve response-time and stability problems associated with the large volume. The performance characteristics of the calorimeter are 1) a linear response between 0 and 320 W (471 g . h-1) for evaporative heat with a precision of 4.0-0.6% in the range 25-100 W, 2) a linear response between 0 and 280 W for sensible heat with a precision of 1.4-0.2% in the range 50-200 W, 3) a stability corresponding to a drift of less than 0.6 W (24 and 72 h) on both evaporative and sensible heat outputs and 24- and 72-h standard deviations (values every 2 min) of 0.3 and 0.4 W for evaporative heat and 0.6 and 0.7 W for sensible heat, 4) response times (95%) of 15 min for both evaporative and sensible heat, 5) independency on the position of the calibration source within the chamber, 6) no measurable "cross talk" between evaporative and sensible heat inputs, 7) negligible dependency of the external air humidity between 14 and 70%, and 8) operating temperature range from 18 to 30 degrees C. More than 40 experiments of 25-h duration with human subjects have been carried out. In no case was any discomfort recorded. An example of the 25-h continuous evaporative and sensible heat output tracing of one experiment is given.

2013 ◽  
Vol 791-793 ◽  
pp. 962-966
Author(s):  
Zhi Jian Qu ◽  
Liang Guo ◽  
Hong Ping Ling ◽  
Ge Chen ◽  
Li Liu

In allusion to the transmission difficult difficulties problem of massive monitoring information flow, due to numerous on-line processing points and quick variation of operating parameters in distribution network monitoring dispatching, an new asynchronous processing method for batch information based on multi-agent alliance technology is proposed. Multi-agent alliance Platform is constructed by means of designing JACK software. Then using CIM-mapping technology and news event asynchronous trigger technology, massive data interactive real-time processing is implemented. Taking the monitoring system for 10kV railway distribution network as example, the synchronous interaction and performance tests are carried out for 10000 analog quantities and state quantity measurement data, the transmission interaction processing time is 582.08ms.


Author(s):  
Toby J. Lloyd-Jones ◽  
Juergen Gehrke ◽  
Jason Lauder

We assessed the importance of outline contour and individual features in mediating the recognition of animals by examining response times and eye movements in an animal-object decision task (i.e., deciding whether or not an object was an animal that may be encountered in real life). There were shorter latencies for animals as compared with nonanimals and performance was similar for shaded line drawings and silhouettes, suggesting that important information for recognition lies in the outline contour. The most salient information in the outline contour was around the head, followed by the lower torso and leg regions. We also observed effects of object orientation and argue that the usefulness of the head and lower torso/leg regions is consistent with a role for the object axis in recognition.


2021 ◽  
Vol 109 (4) ◽  
pp. 243-260 ◽  
Author(s):  
Yves Wittwer ◽  
Robert Eichler ◽  
Dominik Herrmann ◽  
Andreas Türler

Abstract A new setup named Fast On-line Reaction Apparatus (FORA) is presented which allows for the efficient investigation and optimization of metal carbonyl complex (MCC) formation reactions under various reaction conditions. The setup contains a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes at a rate of a few atoms per second by its 3% spontaneous fission decay branch. Those atoms are transformed within FORA in-situ into volatile metal carbonyl complexes (MCCs) by using CO-containing carrier gases. Here, the design, operation and performance of FORA is discussed, revealing it as a suitable setup for performing single-atom chemistry studies. The influence of various gas-additives, such as CO2, CH4, H2, Ar, O2, H2O and ambient air, on the formation and transport of MCCs was investigated. O2, H2O and air were found to harm the formation and transport of MCCs in FORA, with H2O being the most severe. An exception is Tc, for which about 130 ppmv of H2O caused an increased production and transport of volatile compounds. The other gas-additives were not influencing the formation and transport efficiency of MCCs. Using an older setup called Miss Piggy based on a similar working principle as FORA, it was additionally investigated if gas-additives are mostly affecting the formation or only the transport stability of MCCs. It was found that mostly formation is impacted, as MCCs appear to be much less sensitive to reacting with gas-additives in comparison to the bare Mo, Tc, Ru and Rh atoms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tyler J. Adkins ◽  
Bradley S. Gary ◽  
Taraz G. Lee

AbstractIncentives can be used to increase motivation, leading to better learning and performance on skilled motor tasks. Prior work has shown that monetary punishments enhance on-line performance while equivalent monetary rewards enhance off-line skill retention. However, a large body of literature on loss aversion has shown that losses are treated as larger than equivalent gains. The divergence between the effects of punishments and reward on motor learning could be due to perceived differences in incentive value rather than valence per se. We test this hypothesis by manipulating incentive value and valence while participants trained to perform motor sequences. Consistent with our hypothesis, we found that large reward enhanced on-line performance but impaired the ability to retain the level of performance achieved during training. However, we also found that on-line performance was better with reward than punishment and that the effect of increasing incentive value was more linear with reward (small, medium, large) while the effect of value was more binary with punishment (large vs not large). These results suggest that there are differential effects of punishment and reward on motor learning and that these effects of valence are unlikely to be driven by differences in the subjective magnitude of gains and losses.


Author(s):  
Tobias Rieger ◽  
Lydia Heilmann ◽  
Dietrich Manzey

AbstractVisual inspection of luggage using X-ray technology at airports is a time-sensitive task that is often supported by automated systems to increase performance and reduce workload. The present study evaluated how time pressure and automation support influence visual search behavior and performance in a simulated luggage screening task. Moreover, we also investigated how target expectancy (i.e., targets appearing in a target-often location or not) influenced performance and visual search behavior. We used a paradigm where participants used the mouse to uncover a portion of the screen which allowed us to track how much of the stimulus participants uncovered prior to their decision. Participants were randomly assigned to either a high (5-s time per trial) or a low (10-s time per trial) time-pressure condition. In half of the trials, participants were supported by an automated diagnostic aid (85% reliability) in deciding whether a threat item was present. Moreover, within each half, in target-present trials, targets appeared in a predictable location (i.e., 70% of targets appeared in the same quadrant of the image) to investigate effects of target expectancy. The results revealed better detection performance with low time pressure and faster response times with high time pressure. There was an overall negative effect of automation support because the automation was only moderately reliable. Participants also uncovered a smaller amount of the stimulus under high time pressure in target-absent trials. Target expectancy of target location improved accuracy, speed, and the amount of uncovered space needed for the search.Significance Statement Luggage screening is a safety–critical real-world visual search task which often has to be done under time pressure. The present research found that time pressure compromises performance and increases the risk to miss critical items even with automation support. Moreover, even highly reliable automated support may not improve performance if it does not exceed the manual capabilities of the human screener. Lastly, the present research also showed that heuristic search strategies (e.g., areas where targets appear more often) seem to guide attention also in luggage screening.


1995 ◽  
Vol 16 (2) ◽  
pp. 137-154 ◽  
Author(s):  
Rachel E. Stark ◽  
James W. Montgomery

ABSTRACTNineteen language-impaired (LI) and 20 language-normal (LN) children participated in an on-line word-monitoring task. Words were presented in lists and in sentences readily comprehended by younger children. The sentences were unaltered, tow-pass filtered, and time- compressed. Both groups had shorter mean response times (MRTs), but lower accuracy, for words in sentences than words in lists. The LI children had significantly longer MRTs under sentence conditions and lower accuracy overall than the LN children. Filtering had an adverse effect upon accuracy and MRT for both subject groups. Time compression did not, suggesting that the reduction in high-frequency information and the rate of presentation exert different effects. Subject differences in attention, as well as in linguistic competence and motor control, may have influenced word-monitoring performance.


2003 ◽  
Vol 125 (2) ◽  
pp. 208-216 ◽  
Author(s):  
Avram Bar-Cohen ◽  
Madhusudan Iyengar ◽  
Allan D. Kraus

The effort described herein extends the use of least-material single rectangular plate-fin analysis to multiple fin arrays, using a composite Nusselt number correlation. The optimally spaced least-material array was also found to be the globally best thermal design. Comparisons of the thermal capability of these optimum arrays, on the basis of total heat dissipation, heat dissipation per unit mass, and space claim specific heat dissipation, are provided for several potential heat sink materials. The impact of manufacturability constraints on the design and performance of these heat sinks is briefly discussed.


1982 ◽  
Vol 26 (5) ◽  
pp. 435-435
Author(s):  
Dennis B. Beringer ◽  
Susan R. Maxwell

Interest in optimized human-computer interfaces has resulted in the development of a number of interesting devices that allow the computer and human operator to interact through a common drawing surface. These devices include the lightpen, lightgun (Goodwin, 1975), and a variety of touch-sensitive display overlay devices. Although touch devices were being investigated as early as 1965 (Orr and Hopkin, circa 1966), behavioral and performance data are scarce in relation to other sources of human-machine interface data. Availability of these devices has increased in the last 10 years and it is now possible to retrofit such devices to a wide variety of video display terminals at a reasonable cost. With the possibility of increased use looming on the horizon, it would be quite useful to examine the ergonomics of such devices and the behavioral adaptation or maladaptation that occurs for each user. Performance data available at this point from previous studies suggests that some positive increments in performance can be expected for graphic-based tasks while no serious decrements should be expected for discrete data entry tasks (Beringer, 1980; Stammers and Bird, 1980). The performance gains expected from this format of interaction are not to be won without some sacrifice elsewhere, however. Positioning of the display surface for optimum viewing may cause serious operator fatigue problems after extended use of the device if the device is to be used with relatively high frequency. The relationship of device positioning, device sensing resolution, and task type are being examined as they contribute to the comission of errors and the onset of fatigue. Experimentation was planned to examine how positioning of the device, or what can truly be called a “control/display unit”, affected the performance of visual discrimination tasks and manual designation tasks. Initial investigations used a single task to examine these questions by requiring the operator/subject to visually detect and manually designate the location of a break in one of 54 circles presented on a color c.r.t. display (essentially a Landholt C target). Responses were accepted by an infrared touch panel mounted on the display face. The c.r.t. was placed at four declinations during the blocks of trials; 90, 67, 45, and 35 degrees to the line of sight. Although a very strong learning effect was observed over the first 8 blocks of 25 trials each, performance leveled off, on the average, beginning with the ninth block of trials. No reliable effects of screen declination were found in the examination of response times or number of errors. Responses did tend to be located slightly lower than the target, however, for the greater declinations of the display surface. Subjective reports of physical difficulty of responding and fatigue did vary regularly with declination of the display. The relatively high location of the device resulted in shoulder and arm fatigue when the display was at 90 degrees and wrist fatigue when the display was at 35 degrees. Subsequent phases of the investigation will allow subjects to adjust parameters of height and declination (Brown and Schaum, 1980) and will use hand skin temperature and quantified postural information to assess the degree of fatigue incurred during device operation.


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