scholarly journals Clustering and the efficient use of cognitive resources

2021 ◽  
Author(s):  
Ishita Dasgupta ◽  
Thomas L. Griffiths
Keyword(s):  
Bayesian Statistics ◽  
Human Intelligence ◽  
Order Structure ◽  
Central Component ◽  
Cognitive Resources ◽  
Chinese Restaurant Process ◽  
Chinese Restaurant ◽  
Wide Range ◽  
Psychological Models ◽  
Clustering Behavior

A central component of human intelligence is the ability to make abstractions, to gloss over some details in favor of drawing out higher-order structure. Clustering stimuli together is a classic example of this. However, the crucial question remains of how one should make these abstractions -- what details to retain and what to throw away? How many clusters to form? We provide an analysis of how a rational agent with limited cognitive resources should approach this problem, considering not only how well a clustering fits the data but also by how 'complex' it is, i.e. how cognitively expensive it is to represent. We show that the solution to this problem provides a way to reinterpret a wide range of psychological models that are based on principles from non-parametric Bayesian statistics. In particular, we show that the Chinese Restaurant Process prior, ubiquitous in models of human and animal clustering behavior, can be interpreted as minimizing an intuitive formulation of representational complexity.

scholarly journals Novel trajectory clustering method based on distance dependent Chinese restaurant process

2019 ◽  
Vol 5 ◽  
pp. e206
Author(s):  
Reza Arfa ◽  
Rubiyah Yusof ◽  
Parvaneh Shabanzadeh
Keyword(s):  
Trajectory Analysis ◽  
Traffic Monitoring ◽  
Transport Systems ◽  
Trajectory Clustering ◽  
Number Of Clusters ◽  
Chinese Restaurant Process ◽  
Chinese Restaurant ◽  
Wide Range ◽  
Path Modelling ◽  
Traditional Approaches

Trajectory clustering and path modelling are two core tasks in intelligent transport systems with a wide range of applications, from modeling drivers’ behavior to traffic monitoring of road intersections. Traditional trajectory analysis considers them as separate tasks, where the system first clusters the trajectories into a known number of clusters and then the path taken in each cluster is modelled. However, such a hierarchy does not allow the knowledge of the path model to be used to improve the performance of trajectory clustering. Based on the distance dependent Chinese restaurant process (DDCRP), a trajectory analysis system that simultaneously performs trajectory clustering and path modelling was proposed. Unlike most traditional approaches where the number of clusters should be known, the proposed method decides the number of clusters automatically. The proposed algorithm was tested on two publicly available trajectory datasets, and the experimental results recorded better performance and considerable improvement in both datasets for the task of trajectory clustering compared to traditional approaches. The study proved that the proposed method is an appropriate candidate to be used for trajectory clustering and path modelling.

Current Trends in Biotherapeutic Higher Order Structure Characterization by Irreversible Covalent Footprinting Mass Spectrometry

2019 ◽  
Vol 26 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Natalie K. Garcia ◽  
Galahad Deperalta ◽  
Aaron T. Wecksler
Keyword(s):  
Mass Spectrometry ◽  
Protein Structure ◽  
Protein Interactions ◽  
Quaternary Structure ◽  
Solvent Accessibility ◽  
Higher Order ◽  
Structure Characterization ◽  
Order Structure ◽  
Protein Footprinting ◽  
Wide Range

Background: Biotherapeutics, particularly monoclonal antibodies (mAbs), are a maturing class of drugs capable of treating a wide range of diseases. Therapeutic function and solutionstability are linked to the proper three-dimensional organization of the primary sequence into Higher Order Structure (HOS) as well as the timescales of protein motions (dynamics). Methods that directly monitor protein HOS and dynamics are important for mapping therapeutically relevant protein-protein interactions and assessing properly folded structures. Irreversible covalent protein footprinting Mass Spectrometry (MS) tools, such as site-specific amino acid labeling and hydroxyl radical footprinting are analytical techniques capable of monitoring the side chain solvent accessibility influenced by tertiary and quaternary structure. Here we discuss the methodology, examples of biotherapeutic applications, and the future directions of irreversible covalent protein footprinting MS in biotherapeutic research and development. Conclusion: Bottom-up mass spectrometry using irreversible labeling techniques provide valuable information for characterizing solution-phase protein structure. Examples range from epitope mapping and protein-ligand interactions, to probing challenging structures of membrane proteins. By paring these techniques with hydrogen-deuterium exchange, spectroscopic analysis, or static-phase structural data such as crystallography or electron microscopy, a comprehensive understanding of protein structure can be obtained.

scholarly journals A Distance-Dependent Chinese Restaurant Process Based Method for Event Detection on Social Media

Inventions ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 80 ◽  
Author(s):  
Georgios Palaiokrassas ◽  
Athanasios Voulodimos ◽  
Antonios Litke ◽  
Athanasios Papaoikonomou ◽  
Theodora Varvarigou
Keyword(s):  
Social Media ◽  
Event Detection ◽  
Dirichlet Process ◽  
Chinese Restaurant Process ◽  
Chinese Restaurant ◽  
Social Events ◽  
The Social ◽  
Social Event Detection ◽  
Clustering Approach ◽  
Processing Steps

In this paper, we propose a method for event detection on social media, which aims at clustering media items into groups of events based on their textural information as well as available metadata. Our approach is based on distance-dependent Chinese Restaurant Process (ddCRP), a clustering approach resembling Dirichlet process algorithm. Furthermore, we scrutinize the effectiveness of a series of pre-processing steps in improving the detection performance. We experimentally evaluated our method using the Social Event Detection (SED) dataset of MediaEval 2013 benchmarking workshop, which pertains to the discovery of social events and their grouping in event-specific clusters. The obtained results indicate that the proposed method attains very good performance rates compared to existing approaches.

scholarly journals Nicholas John Seymour Mackintosh. 9 July 1935—8 February 2015

2018 ◽  
Vol 64 ◽  
pp. 299-316 ◽  
Author(s):  
John M. Pearce
Keyword(s):  
Formal Theory ◽  
Human Intelligence ◽  
Theoretical Context ◽  
Experimental Psychologist ◽  
Wide Range ◽  
To Come ◽  
Learning And Cognition ◽  
The Relationship ◽  
Over 40 Years

Nicholas Mackintosh was an experimental psychologist whose principal goal was to understand the basic mechanisms of learning and cognition, largely through research with animals. The two textbooks that he wrote on this topic synthesized a vast body of research and set it within a theoretical context of association formation that has remained dominant for over 40 years. He developed a formal theory of the relationship between attention and learning that had an immediate impact and can be expected to be the foremost theory of its kind for many years to come. He was also a prolific experimenter, whose ingenious experiments were remarkable for the theoretical insights they offered into the mechanisms of learning in a wide range of species. Towards the end of his career, he developed an interest in the measurement of human intelligence. The textbook that followed from this interest is one of the most authoritative ever written on the topic.

Structure functions of turbulence in the atmospheric boundary layer over the ocean

1970 ◽  
Vol 44 (1) ◽  
pp. 145-159 ◽  
Author(s):  
C. W. Van Atta ◽  
W. Y. Chen
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Fourth Order ◽  
Structure Functions ◽  
Inertial Subrange ◽  
Order Structure ◽  
Third Order ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Order Quantities

Structure functions of turbulent velocity fluctuations up to fourth order have been measured at several heights in the atmospheric boundary layer over the open ocean, and the results are compared with theoretical predictions for separations in the inertial subrange. The behaviour of second- and third-order quantities shows substantial agreement with the predictions of Kolmogorov's original theory over a wide range of separations, but the results of a recent modification of the theory, attempting to account for intermittency in the local dissipation rate, are also consistent with the data over somewhat shorter separation intervals. The behaviour of the measured fourth-order structure function disagrees with that predicted from Kolmogorov's original work, but good agreement is found with the results of the modified theory.

Variable Resolution Fluctuation Electron Microscopy on Cu-Zr Metallic Glass Using a Wide Range of Coherent STEM Probe Size

2010 ◽  
Vol 17 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Jinwoo Hwang ◽  
P.M. Voyles
Keyword(s):  
Electron Microscopy ◽  
Metallic Glass ◽  
Dark Field ◽  
Order Structure ◽  
Specimen Thickness ◽  
Variable Resolution ◽  
Wide Range ◽  
Scanning Transmission ◽  
Annular Dark Field ◽  
Fluctuation Electron Microscopy

AbstractWe report variable resolution fluctuation electron microscopy (VRFEM) measurements on Cu64.5Zr35.5metallic glass acquired using scanning transmission electron microscopy nanodiffraction using coherent probes 0.8 to 11 nm in diameter. The VRFEM results show that medium range atomic order structure of Cu64.5Zr35.5bulk metallic glass at the ∼1 nm scale has large fluctuations, but the structure becomes almost completely homogeneous at the 11 nm scale. We show that our experimental VRFEM data are consistent with two different models, the pair persistent model and the amorphous/nanocrystal composite model. We also report a new way to filter VRFEM data to eliminate the effect of specimen thickness gradient using high-angle annular dark field images as references.

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