Capacity Theory with Local Rationality

Author(s):  
Robert Rumely
Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 773
Author(s):  
Amichai Painsky ◽  
Meir Feder

Learning and making inference from a finite set of samples are among the fundamental problems in science. In most popular applications, the paradigmatic approach is to seek a model that best explains the data. This approach has many desirable properties when the number of samples is large. However, in many practical setups, data acquisition is costly and only a limited number of samples is available. In this work, we study an alternative approach for this challenging setup. Our framework suggests that the role of the train-set is not to provide a single estimated model, which may be inaccurate due to the limited number of samples. Instead, we define a class of “reasonable” models. Then, the worst-case performance in the class is controlled by a minimax estimator with respect to it. Further, we introduce a robust estimation scheme that provides minimax guarantees, also for the case where the true model is not a member of the model class. Our results draw important connections to universal prediction, the redundancy-capacity theorem, and channel capacity theory. We demonstrate our suggested scheme in different setups, showing a significant improvement in worst-case performance over currently known alternatives.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng-Cheng Zhang ◽  
Bin Shi ◽  
Song Zhang ◽  
Kai Gu ◽  
Su-Ping Liu ◽  
...  

AbstractVertical deformation profiles of subterranean geological formations are conventionally measured by borehole extensometry. Distributed strain sensing (DSS) paired with fiber-optic cables installed in the ground opens up possibilities for acquiring high-resolution static and quasistatic strain profiles of deforming strata, but it is currently limited by reduced data quality due to complicated patterns of interaction between the buried cables and their surroundings, especially in upper soil layers under low confining pressures. Extending recent DSS studies, we present an improved approach using microanchored fiber-optic cables—designed to optimize ground-to-cable coupling at the near surface—for strain determination along entire lengths of vertical boreholes. We proposed a novel criterion for soil–cable coupling evaluation based on the geotechnical bearing capacity theory. We applied this enhanced methodology to monitor groundwater-related vertical motions in both laboratory and field experiments. Corroborating extensometer recordings, acquired simultaneously, validated fiber optically determined displacements, suggesting microanchored DSS as an improved means for detecting and monitoring shallow subsurface strain profiles.


2021 ◽  
pp. 014473942110194
Author(s):  
Bobby Thomas Cameron

A substantial amount of scholarly work focuses on conceptualizing, theorizing and studying the policy capacity of governments. Yet, guidance for practitioners on developing policy capacity training programs is lacking. In this article, I reflect on my experience as a public servant in the provincial government of Prince Edward Island where I designed and implemented the Policy Capacity Development and Mentorship Program for civil servants, recent graduates and students. In this article, I offer a descriptive overview of the framework and logic of the program and discuss how I integrated policy capacity theory. This article may serve other practitioners who seek to implement similar programs in their respective organizations and provides a base for future interventions. The article also offers thoughts on practitioner-led collaboration with academics and recommendations for those who would like to establish similar programs in their organizations.


2018 ◽  
Author(s):  
James Hambleton ◽  
Samuel Stanier

This paper assesses the applicability of bearing capacity theory for evaluating the forces generated on wheels operating on clay under steady rolling conditions. Considering recent advances in bearing capacity theory, namely with respect to the interaction diagrams developed for general loading, a theoretical model for computing the horizontal force or torque from fundamental input parameters such as the vertical force (weight), wheel diameter, and undrained shear strength of the soil is presented. The predictions are compared with existing analytical solutions and data from laboratory testing, and reasonable agreement is demonstrated. The foremost conclusion is that bearing capacity theory can be used to obtain reasonable predictions of wheel forces analytically under any operating condition (driven, braked, or towed), provided the contact length and so-called contact angle, which defines the position of the contact interface, can be estimated. Aside from providing a rigorous and highly convenient framework for evaluating wheel forces under arbitrary loading, the analysis enables a natural physical interpretation of the mobility problem.


2020 ◽  
Vol 15 (6) ◽  
pp. 171
Author(s):  
Said Shabban Abdo ◽  
David Edgar ◽  
Gamal Kamel

The purpose of this research is to provide new insights into the moderating effects that enable an MNE operating in Egypt to learn to attract, motivate, transform and develop its high-potential local employees for reverse adaptation so as to fit a global mind-set elsewhere in the organisation’s global positions. The methodology uses semi-structured story-based interviews to explore the significance of moderating effects and practices of absorptive capacity and reverse adaptation in Hi Tech in Egypt. The findings reveal the interrelated components that lead to reverse adaptation and how continuous management development is intermediated by learning and well-bonded reciprocity of relationships, amid continuous management development, transformation, and reverse adaptation. This virtuous cycle acts as an integrated adaptation learning loop that supports the process of transformation. The findings refute the linearity of the absorptive capacity model as the transformation stage does not appear to mediate the model but precedes other steps within it. Moreover, it was concluded that the model did not end in achieving the competitive advantage phase. Instead reverse adaptation, as a by-product, acted as a trigger for knowledge acquisition. The originality here is based on a greater understanding of the moderating effects that mediate the relationship between reverse adaptation and the transformation stage of absorptive capacity theory. This allows awareness of how, in the case of the Hi Tech in Egypt, the global mindset is delivered and offers valuable contributions to theory and practice. As reverse adaptation is a nascent multidisciplinary phenomenon for research, the paper also suggests a research agenda for researchers in the area of international management.


2018 ◽  
Author(s):  
Yi-Jie Zhao ◽  
Tianye Ma ◽  
Xuemei Ran ◽  
Li Zhang ◽  
Ru-Yuan Zhang ◽  
...  

AbstractSchizophrenia patients are known to have profound deficits in visual working memory (VWM), and almost all previous studies attribute the deficits to decreased memory capacity. This account, however, ignores the potential contributions of other VWM components (e.g., memory precision). Here, we measure the VWM performance of schizophrenia patients and healthy control subjects on two classical delay-estimation tasks. Moreover, we thoroughly evaluate several established computational models of VWM to compare the performance of the two groups. We find that the model assuming variable precision across items and trials is the best model to explain the performance of both groups. According to the variable-precision model, schizophrenia subjects exhibit abnormally larger variability of allocating memory resources rather than resources per se. These results invite a rethink of the widely accepted decreased-capacity theory and propose a new perspective on the diagnosis and rehabilitation of schizophrenia.


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