GROUP FORMATION AMONG DECENTRALIZED AUTONOMOUS AGENTS

This paper examines a method of clustering within a fully decentralized multi-agent system. Our goal is to group agents with similar objectives or data, as is done in traditional clustering. However, we add the additional constraint that agents must remain in place on a network, instead of first being collected into a centralized database. To do this, we connect agents in a random overlay network and have them search in a peer-to-peer fashion for other similar agents. We thus aim to tackle the basic clustering problem on an Internet scale, and create a method by which agents themselves can be grouped, forming coalitions. In order to investigate the feasibility of this decentralized approach, this paper presents simulation experiments that look into the quality of the clusters discovered. First, the clusters found by the agent method are compared to those created by k-means clustering for two-dimensional spatial data points. Results show that the decentralized agent method produces a better clustering than the centralized k-means algorithm, placing 95% to 99% of points correctly. A further experiment explores how agents can be used to cluster a straightforward text document set, demonstrating that agents can discover clusters and keywords that are reasonable estimates of those identified by the central word vector space approach.     

SENSORY RESTRICTION WITH ISOLATION EXPERIENCES IN CHILDREN WITH PHENYLKETONURIA.

COMPARED 2 GROUPS OF CHILDREN WITH PHENYLKETONURIA, THOSE WITH A HISTORY OF EARLY SENSORY RESTRICTION OR ISOLATION AND THOSE WITHOUT, ON: (1) INTERPERSONAL BEHAVIOR, (2) LANGUAGE COMPREHENSION, (3) INTELLIGENCE, AND (4) INCIDENCE AND SEVRITY OF PERSONALITY DISTURBANCES. THE FINDINGS, DISCUSSED IN THE CONTEXT OF SENSORY-DEPRIVATION AND SENSORY-RESTRICTION RESEARCH, SUPPORTED THE HYPOTHESIS THAT EARLY ALTERATIONS IN SENSORY ENVIRONMENT LEAD TO LATER IMPAIRMENT IN INTERPERSONAL, EMOTIONAL, AND INTELLECTUAL FUNCTIONING. THE DEGREE OF THIS IMPAIRMENT WAS FOUND TO BE RELATED TO AGE AT THE TIME OF THE EARLY STRESS EXPERIENCE, BUT NOT TO THE DURATION OF SENSORY RESTRICTION OR ISOLATION. (34 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)