13,344 research outputs found
Passing Muster: Evaluating Teacher Evaluation Systems
Describes how state or federal governments could reward exceptional teachers based on a uniform standard across various district-level teacher evaluation systems by determining the systems' reliability in predicting future performance. Includes Q & A
Statistics, Causality and Bell's Theorem
Bell's [Physics 1 (1964) 195-200] theorem is popularly supposed to establish
the nonlocality of quantum physics. Violation of Bell's inequality in
experiments such as that of Aspect, Dalibard and Roger [Phys. Rev. Lett. 49
(1982) 1804-1807] provides empirical proof of nonlocality in the real world.
This paper reviews recent work on Bell's theorem, linking it to issues in
causality as understood by statisticians. The paper starts with a proof of a
strong, finite sample, version of Bell's inequality and thereby also of Bell's
theorem, which states that quantum theory is incompatible with the conjunction
of three formerly uncontroversial physical principles, here referred to as
locality, realism and freedom. Locality is the principle that the direction of
causality matches the direction of time, and that causal influences need time
to propagate spatially. Realism and freedom are directly connected to
statistical thinking on causality: they relate to counterfactual reasoning, and
to randomisation, respectively. Experimental loopholes in state-of-the-art Bell
type experiments are related to statistical issues of post-selection in
observational studies, and the missing at random assumption. They can be
avoided by properly matching the statistical analysis to the actual
experimental design, instead of by making untestable assumptions of
independence between observed and unobserved variables. Methodological and
statistical issues in the design of quantum Randi challenges (QRC) are
discussed. The paper argues that Bell's theorem (and its experimental
confirmation) should lead us to relinquish not locality, but realism.Comment: Published in at http://dx.doi.org/10.1214/14-STS490 the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Enroute flight planning: The design of cooperative planning systems
Design concepts and principles to guide in the building of cooperative problem solving systems are being developed and evaluated. In particular, the design of cooperative systems for enroute flight planning is being studied. The investigation involves a three stage process, modeling human performance in existing environments, building cognitive artifacts, and studying the performance of people working in collaboration with these artifacts. The most significant design concepts and principles identified thus far are the principle focus
An Application of Deep Learning for Sweet Cherry Phenotyping using YOLO Object Detection
Tree fruit breeding is a long-term activity involving repeated measurements
of various fruit quality traits on a large number of samples. These traits are
traditionally measured by manually counting the fruits, weighing to indirectly
measure the fruit size, and fruit colour is classified subjectively into
different color categories using visual comparison to colour charts. These
processes are slow, expensive and subject to evaluators' bias and fatigue.
Recent advancements in deep learning can help automate this process. A method
was developed to automatically count the number of sweet cherry fruits in a
camera's field of view in real time using YOLOv3. A system capable of analyzing
the image data for other traits such as size and color was also developed using
Python. The YOLO model obtained close to 99% accuracy in object detection and
counting of cherries and 90% on the Intersection over Union metric for object
localization when extracting size and colour information. The model surpasses
human performance and offers a significant improvement compared to manual
counting.Comment: Published in 25th International Conference on Image Processing,
Computer Vision, & Pattern Recognition (IPCV'21
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