Joao Kogler

Universidade de São Paulo, Escola Politécnica, Senior Researcher

Followers

Following

Co-author

Public Views

I currently work at the Electronic Systems Department - Polytechnic School of Engineering (PSI) (POLI), University of São Paulo. My main research activities are in cognitive science and computational intelligence. Additionally, I also do collaborative work with others in my prior research areas, of Computer Vision, Image Processing and Electrical Engineering.
Address: São Paulo, São Paulo, Brazil

less

InterestsView All (7)

Uploads

Papers by Joao Kogler

Toward Working Definitions of Cognitive Processes Suitable for Design Specifications of BICA

Studies in computational intelligence, 2022

WOXBOT: a wide open extensible robot for virtual world simulations

This paper reports some activities towards artificial life research. We propose the implementatio... more This paper reports some activities towards artificial life research. We propose the implementation of a society of virtual mobile robots, able to perform requested tasks while behaving according to their own motivation and reasoning. Each robot is an intelligent agent that perceives the virtual environment via a simulated vision system and reacts moving its own body by driving its own wheels. The robot also communicates with other robots placed near to itself, through a simulated talking and listening (prototypical hearing) system. This feature allows them to communicate with each other, giving support for the evolution of their social skills. The conception and specification of the robots and the environment are being conducted very carefully to create an open distributed object architecture that could serve as a testbed freely available and ready to use for testing theories in some computational areas. Our intention is to test concepts in evolutionary computation, artificial life,...

Download

Computação Cognitiva - Computação, Cognição, Vida Artificial e Bio-Informática

On the Requirements for Simulating a Memory Evolutive System

This paper discusses aspects of the simulation of a memory evolutive system (MES) by means of an ... more This paper discusses aspects of the simulation of a memory evolutive system (MES) by means of an artificial neural network. We address here the issues concerning the minimum requirements that a neuron model should fulfill in order that the network would be capable of expressing the categories underlying the MES. We conclude that Izhikevitch's formal neuron has sufficient dynamical properties to achieve these requirements.

Download

PSI-2222-Práticas de Eletricidade e Eletrônica

Primary ciliary dyskinesia: evaluation using cilia beat frequency assessment via spectral analysis of digital microscopy images

Ciliary beat frequency (CBF) measurements provide valuable information for diagnosing of primary ... more Ciliary beat frequency (CBF) measurements provide valuable information for diagnosing of primary ciliary dyskinesia (PCD). We developed a system for measuring CBF, used it in association with electron microscopy to diagnose PCD, and then analyzed characteristics of PCD patients. 1 The CBF measurement system was based on power spectra measured through digital imaging. Twenty-four patients suspected of having PCD (age 1-19 yr) were selected from a group of 75 children and adolescents with pneumopathies of unknown causes. Ten healthy, nonsmoking volunteers (age Ն17 yr) served as a control group. Nasal brush samples were collected, and CBF and electron microscopy were performed. PCD was diagnosed in 12 patients: 5 had radial spoke defects, 3 showed absent central microtubule pairs with transposition, 2 had outer dynein arm defects, 1 had a shortened outer dynein arm, and 1 had a normal ultrastructure. Previous studies have reported that the most common cilia defects are in the dynein arm. As expected, the mean CBF was higher in the control group (P Ͻ 0.001) and patients with normal ultrastructure (P Ͻ 0.002), than in those diagnosed with cilia ultrastructural defects (i.e., PCD patients). An obstructive ventilatory pattern was observed in 70% of the PCD patients who underwent pulmonary function tests. All PCD patients presented bronchial wall thickening on chest computed tomography scans. The protocol and diagnostic techniques employed allowed us to diagnose PCD in 16% of patients in this study. Kartagener's syndrome; ciliary motility disorders PRIMARY CILIARY DYSKINESIA (PCD) is a genetically heterogeneous disorder of motile cilia. It is characterized by ciliary dysfunction and impaired mucociliary clearance, and it results in an array of clinical manifestations, including bronchitis leading to bronchiectasis, chronic rhinosinusitis, chronic otitis media, situs inversus (in 50% of cases), and male infertility (5, 30, 31). The cardinal features of PCD include upper and lower respiratory tract disorders (31). The incidence of PCD is ϳ1/15,000 (5). Diagnostic screening tests for PCD include (5, 20, 37) the saccharin test, which is unreliable in children under the age of 12 yr because it requires subject collaboration; mucociliary clearance by aerosol, which is seldom used (13, 32); and nasal

Download

Using independent subspace analysis to build independent spectral representations of images

In this work we propose the use of independent subspace analysis (ISA) for selecting filters used... more In this work we propose the use of independent subspace analysis (ISA) for selecting filters used to build image representations. ISA is an extension of independent component analysis (ICA), a technique employed to decompose an image into independent features. In ISA, complete independence of features is not required; features that possess some mutual dependence are associated in feature subspaces. A

Artificial life: towards new generation of computer animation

Computers & Graphics, 2001

Artificial life: towards new generation of computer animation 0097-8493/01/$ -see front matter r ... more

Download

Using independent subspace analysis for selecting filters used in texture processing

In this work we propose the use of independent subspace analysis (ISA) for selecting filters used... more In this work we propose the use of independent subspace analysis (ISA) for selecting filters used for texture processing. ISA is an extension of independent component analysis (ICA), a technique employed to decompose an image into statistically independent features. In ISA, complete independence of features is not required; features that possess some mutual dependence are associated in feature subspaces. An

Arena and Woxbot: First Steps Towards Virtual World Simulations

This paper reports new results of a project to build virtual worlds aimed at the graphic simulati... more This paper reports new results of a project to build virtual worlds aimed at the graphic simulation of an arena where small mobile robots can perform requested tasks while behaving according to their own motivation and reasoning. Each robot is an intelligent agent that perceives the virtual environment via a simulated vision system and reacts translating or rotating its body by driving its own wheels. The conception and specification of the robots and the environment are being done very carefully to create an open distributed object architecture that could serve as a testbed freely available and ready to use for testing theories in some computational areas such as evolutionary computation, artificial life, pattern recognition, artificial intelligence, cognitive neurosciences and distributed objects architectures.

Download

An artificial life approach for the animation of cognitive characters

Computers & Graphics, 2001

This paper addresses the problem of cognitive character animation. We propose the use of finite s... more This paper addresses the problem of cognitive character animation. We propose the use of finite state machines for the behavioral control of characters. Our approach rests on the idea that the cognitive character arises from the evolutionary computation embedded in the artificial life simulation, which in our case is implemented by the finite state machine. We present some of the results of the WOXBOT/ARENA research project. This project to build virtual worlds is aimed at the graphic simulation of an arena, where small mobile robots can perform requested tasks while behaving according to their own motivation and reasoning. Each robot is an intelligent agent that perceives the virtual environment through a simulated vision system and reacts by moving away from or approaching the object it sees. The conception and specification of the robots and environment are being done very carefully to create an open distributed object architecture that could serve as a test-bed freely available and ready to use for testing theories in some computational areas such as evolutionary computation, artificial life, pattern recognition, artificial intelligence, cognitive neurosciences and distributed objects architectures. Furthermore, it is a first step towards building a cognitive animated character.

Download

Graphic Simulation for Virtual Prototyping with JAVA3D

We report some issues involved in the construction of an interactive, interoperable application, ... more We report some issues involved in the construction of an interactive, interoperable application, whose primary purpose is to be used as a virtual mockup. This graphic tool was tailored for machine vision application prototyping, to cope with metrological settings of large part assemblies. Some relevant aspects of designing interactive 3D applications will be discussed, including an account of some modern graphics libraries, particularly Java 3D. The achieved results, including some interesting byproducts of this work, to be publicly distributed soon, are also presented.

Bistable memory and binary counters in spiking neural network

Information can be encoded in spiking neural network (SNN) by precise spike-time relations. This ... more Information can be encoded in spiking neural network (SNN) by precise spike-time relations. This hypothesis can explain cell assembly formation, such as polychronous group (PNG), a notion created to explain how groups of neurons fire time-locked to each other, not necessarily synchronously. In this paper we present a set of PNGs capable of retaining triggering events in bistable states. Triggering events may be data or computational controls. Both, data and control signals are memorized as a result of intrinsic operational PNG attributes, and no neural plasticity mechanisms are involved. This behavior can be fundamental for several computational operations in SNNs. It is shown how bistable neural pools can perform tasks such as binary and stack-like counting, and how they can realize hierarchical organization in parallel computing.

Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers

Anais Da Academia Brasileira De Ciencias, 2001

The brain is an excitable media in which excitation waves propagate at several scales of time and... more The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''Onedimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.

Download

On Building a Memory Evolutive System for Application to Learning and Cognition Modeling

by Joao Kogler and João Ranhel

We address here aspects of the implementation of a memory evolutive system (MES), based on the mo... more We address here aspects of the implementation of a memory evolutive system (MES), based on the model proposed by A. Ehresmann and J. Vanbremeersch (2007), by means of a simulated network of spiking neurons with time dependent plasticity. We point out the advantages and challenges of applying category theory for the representation of cognition, by using the MES architecture. Then we discuss the issues concerning the minimum requirements that an artificial neural network (ANN) should fulfill in order that it would be capable of expressing the categories and mappings between them, underlying the MES. We conclude that a pulsed ANN based on Izhikevich’s formal neuron with STDP (spike time-dependent plasticity) has sufficient dynamical properties to achieve these requirements, provided it can cope with the topological requirements. Finally, we present some perspectives of future research concerning the proposed ANN topology.

WOXBOT: a Wide Open Extensible Robot for Virtual World Simulations

Download

Joao Kogler

Uploads

Papers by Joao Kogler

Log In