Analysis, Evaluation and Improvement of Sequential Single-Item Auctions for the Cooperative Real-Time Allocation of Tasks

2013 ◽  
Author(s):  
Sven Koenig ◽  
Craig Tovey
Keyword(s):  
Real Time ◽  
Time Allocation ◽  
Single Item ◽  
Single Item Auctions

Real-time handheld emission spot allocator (rthESA) for simultaneous fusion imaging with ultrasound

2014 ◽  
Vol 53 (06) ◽  
pp. 265-271 ◽  
Author(s):  
T. Winkens ◽  
C. Kühnel ◽  
M. Freesmeyer
Keyword(s):  
Real Time ◽  
Time Allocation ◽  
Ad Hoc ◽  
Fusion Imaging ◽  
Semiconductor Detectors ◽  
Single Plane ◽  
Technical Parameters ◽  
Simultaneous Acquisition ◽  
Radiation Sources ◽  
Liver Phantom

SummaryObjectives: First, to report on initial experiences and technical parameters of a newly developed real-time handheld emission spot allocator (rthESA), and second, to report on the simultaneous acquisition of rthESA and US data as rthESA/US fusion images. Methods: The rthESA consisted of five semiconductor-detectors arranged in alternate position in two rows. This design allowed the examination of focal activities in the same plane as US. The signals were interpreted by an ad hoc software and the real-time allocation of spot radiation sources within air- and water phantoms was investigated for 99mTc, 131I, and 18F. A compact US probe was fixed in plane with the rthESA and connected to a standard US equipment. Experiments with a liver phantom were performed to verify the integration of 99mTc-rthESA data and US images. Results: The allocation proved to be successful for all radionuclides. The system showed a noticeable performance latency, most pronounced for positions far from the detector (1 cm distance: 0.7 ± 0.5 s; 4 cm distance: 6.1 ± 3.2 s). Within the liver phantom, the rthESA enabled the correct allocation of a spot radiation source within a live US image. Conclusions: The rthESA allowed an exact localization of spot radiation sources in single plane, with additional consideration of the distance from the detector, leading to real-time allocation and simultaneous overlay with US images. In spite of clear technical limitations in need of further development, this proof-of-concept study shows that this hybrid detector has the potential to provide integrated simultaneous nuclear medicine and US images.

Second Chances in Learning: Does a Resit Prospect Lower Study-Time Investments on a First Test?

2021 ◽  
Author(s):  
Rob Nijenkamp ◽  
Mark Nieuwenstein ◽  
Ritske De Jong ◽  
Monicque Lorist
Keyword(s):  
Real Time ◽  
Time Allocation ◽  
Multiple Choice ◽  
Study Time ◽  
Questionnaire Study ◽  
Choice Test ◽  
Multiple Choice Test ◽  
Advance Study ◽  
Study Time Allocation ◽  
Allocation Decisions

Previous studies have shown that the prospect of a resit opportunity lowers fictional study-time investments for a first exam, as compared to a single-chance exam (i.e., the resit effect). The present paper describes two experiments in which we aimed to generalize this effect from fictional study-time investments to a task where participants invested real time to study pairs of pseudo words for a subsequent multiple-choice test, given either a single chance or two chances to pass. Against our expectations based on previous results, the results of the current experiments showed no resit effect for the amount of time participants spent studying the materials. Taken together with previous findings and novel findings from a questionnaire study also reported in this paper, this finding leads us to argue that a resit prospect may primarily affect advance study-time allocation decisions.

scholarly journals Coordinated Secondary Frequency Regulation Strategy of Doubly-Fed Induction Generator and Electric Vehicle

2019 ◽  
Vol 9 (14) ◽  
pp. 2815
Author(s):  
Qian Zhang ◽  
Yan Li ◽  
Chen Li ◽  
Zhuwei Ding ◽  
Wenrui Xie
Keyword(s):  
Wind Speed ◽  
Real Time ◽  
Electric Vehicle ◽  
Time Allocation ◽  
Pitch Angle ◽  
Induction Generator ◽  
Frequency Regulation ◽  
Doubly Fed Induction Generator ◽  
Doubly Fed ◽  
System Frequency

Wind turbines can participate in frequency regulation by controlling active power output, but the indeterminacy and volatility of wind power result in low reliability of frequency support. Therefore, as a kind of energy storage system, an electric vehicle is adopted to coordinate with wind turbines to regulate system frequency considering its large-scale development. First, based on the reasonable division of wind speed regions and operation point selection of pitch angle, the de-loading strategy of doubly-fed induction generator for reserve capacity under continuously varying wind speed is proposed. Then, through the combination of rotor speed and pitch angle control, frequency regulation model of a doubly-fed induction generator in whole wind speed range is established. Finally, taking into account the driving demand of electric vehicle owners, through the real-time allocation of system frequency regulation task based on frequency regulation capacity, the coordinated control strategy of doubly-fed induction generator and electric vehicle cluster for secondary frequency regulation is put forward. The simulation results show that the coordinated frequency regulation strategy based on real-time allocation can suppress frequency deviation effectively, and the regulation effect is better than the situations of wind turbine coordinating with the conventional unit or coordinating with electric vehicle cluster based on fixed allocation ratio.

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