John Placer - Academia.edu (original) (raw)

Papers by John Placer

Journal of the Acoustical Society of America, May 1, 2006

Kohonen self-organizing neural networks, also called self-organizing maps (SOMs), have been used ... more Kohonen self-organizing neural networks, also called self-organizing maps (SOMs), have been used successfully to recognize human phonemes and in this way to aid in human speech recognition. This paper describes how SOMS also can be used to associate specific information content with animal vocalizations. A SOM was used to identify acoustic units in Gunnison's prairie dog alarm calls that were vocalized in the presence of three different predator species. Some of these acoustic units and their combinations were found exclusively in the alarm calls associated with a particular predator species and were used to associate predator species information with individual alarm calls. This methodology allowed individual alarm calls to be classified by predator species with an average of 91% accuracy. Furthermore, the topological structure of the SOM used in these experiments provided additional insights about the acoustic units and their combinations that were used to classify the target alarm calls. An important benefit of the methodology developed in this paper is that it could be used to search for groups of sounds associated with information content for any animal whose vocalizations are composed of multiple simultaneous frequency components.

Computer Applications in Engineering Education, 1997

The incorporation of object-oriented techniques into the undergraduate curriculum has received si... more The incorporation of object-oriented techniques into the undergraduate curriculum has received significant attention over the past few years. In this article we will discuss the design, implementation, and application of an object-oriented digital logic simulator. The article explores the advantages of using an object-oriented approach in modeling hardware and it further describes the potential of using such a simulator in a computer-assisted design environment for teaching and research endeavors at the undergraduate level.

This paper presents a discussion of why languages that support multiple paradigms (i.e. multipara... more This paper presents a discussion of why languages that support multiple paradigms (i.e. multiparadigm languages) have the potential to be good pedagogical tools for teaching programming skills. Several examples are given that demonstrate how different programming paradigms are expressed in a working multiparadigm language. The examples, though brief, provide a glimpse of how much expressiveness a simple multiparadigm design can embody and they suggest that the potential role of multiparadigm languages as teaching tools is promising.

Behavioural Processes, Oct 1, 2000

In this study we describe the design and application of an automated classification system that u... more In this study we describe the design and application of an automated classification system that utilizes artificial intelligence to corroborate the finding that Gunnison's prairie dogs have different alarm calls for different species of predators. This corroboration is strong because it utilizes an entirely different analysis technique than that used in the original research by Slobodchikoff et al. [

Behavioural Processes, Jul 1, 2004

In this study, we present a methodology that identifies acoustic units in Gunnison's prai... more In this study, we present a methodology that identifies acoustic units in Gunnison's prairie dog alarm calls and then uses those units to classify the alarm calls and bouts according to the species of predator that was present when the calls were vocalized. While traditional methods measure specific acoustic parameters in order to describe a vocalization, our method uses the variation in the internal structure of a vocalization to define possible information structures. Using a simple representation similar to that used in human speech to identify vowel sounds, a software system was developed that uses this representation to recognize acoustic units in prairie dog alarm calls. These acoustic units are then used to classify alarm calls and their associated bouts according to the species of predator that was present when the alarm calls were vocalized. Identification of bouts with up to 100% accuracy was obtained. This work represents a first step toward revealing the details of how information is encoded in a complex nonhuman communication system. Furthermore, the techniques discussed in this paper are not restricted to a database of prairie dog alarm calls. They could be applied to any animal whose vocalizations include multiple simultaneous frequencies.

Intelligent Automation and Soft Computing, 2007

Severe atmospheric and road surface conditions on rural highways create a variety of transportati... more Severe atmospheric and road surface conditions on rural highways create a variety of transportation hazards. Variable Speed Limit (VSL) systems can mitigate the dangers caused by these conditions by displaying prudent maximum speed limits that reflect the prevailing atmospheric and road surface conditions. This paper discusses the design and implementation of a fuzzy rulebased system (FRBS) that serves as the computational engine of a prototype VSL system designed for use on rural highways. The design of the FRBS is based on Bart Kosco's Standard Additive Model. This model defines a representation of fuzzy systems that is powerful but also conceptually and computationally simple. The FRBS was used in preliminary tests of a prototype VSL system that utilized information transmitted by Road Weather Information Stations located along the I-40 corridor in rural Northern Arizona. This corridor is subject to various types of inclement weather conditions as it passes through a variety of geographic locations that range from desert to mountainous terrain.

Sigplan Notices, Feb 1, 1992

In order to design a broadly multiparadigm language, i.e., a language that directly supports seve... more In order to design a broadly multiparadigm language, i.e., a language that directly supports several diverse programming paradigms, one must integrate a number of seemingly incompatible paradigmatic attributes. Among the most formidable of these antagonists are the time-independent and the time-dependent features of the diverse paradigms that are to be integrated into the language design. Although at some level these antagonists are inherently irreconcilable, finding an appropriate level of integration for such diverse elements can be a significant contribution to a broadly multiparadigm language design. In order to demonstrate this, we first briefly introduce the language G-2, the latest version of the multiparadigm language G. We focus on a new linguistic feature, called a block, that was introduced into G-2 in order to reconcile the facilities of destructive assignment and lazy evaluation. Finally we examine how the block supports many of the paradigms included in G-2 in a simple and direct manner.

Sigplan Notices, Jan 2, 1991

Multiparadigm research is a relatively new direction in programming language design. In this pape... more Multiparadigm research is a relatively new direction in programming language design. In this paper we discuss several aspects of this research area. We consider some of the ideas that underlie the multiparadigm point of view, we examine some of the motivations behind the work being done and we consider some of the directions within this field of work. Finally we offer a short example that suggests the potential usefulness of combining several paradigms into one linguistic framework.

In 1998 Northern Arizona University (NAU) and the Arizona Department of Transportation (ADOT) des... more In 1998 Northern Arizona University (NAU) and the Arizona Department of Transportation (ADOT) designed and implemented the prototype of a variable speed limit (VSL) system for rural highways. The VSL system implements a real-time fuzzy control algorithm that utilizes information provided by Road Weather Information Stations (RWIS). This system continuously displays highway speeds appropriate to the atmospheric and road surface conditions at locations of interest along the I-40 corridor in rural northern Arizona. At the time of this initial project, none of the RWIS sites along I-40 were providing the complete data set needed for full utilization of the fuzzy control algorithm. During the project described in this paper an RWIS site on I-40 was fully upgraded so that it could be used as a test site to monitor the complete data set of atmospheric and road surface conditions needed by the fuzzy control algorithm. In addition to this a traffic detection system was added to the RWIS site

In a previous project, Northern Arizona University (NAU) and the Arizona Department of Transporta... more In a previous project, Northern Arizona University (NAU) and the Arizona Department of Transportation (ADOT) designed and implemented the prototype of a variable speed limit (VSL) system for rural highways. The VSL system implements a real-time fuzzy control algorithm that utilizes information provided by Road Weather Information Stations (RWIS). This system continuously displays highway speeds appropriate to the atmospheric and road surface conditions at locations of interest along the I-40 corridor in rural northern Arizona. At the time of this initial project, none of the RWIS sites along I-40 were providing the complete data set needed for full utilization of the fuzzy control algorithm. A main objective of the current project described in this document was to fully upgrade an RWIS site on I-40 so that it could be used as a test site to monitor the complete data set of atmospheric and road surface conditions needed by the fuzzy control algorithm. A second objective was to enhance this upgraded site so that it would supply traffic flow data. The remaining objectives of the project were to collect atmospheric, road surface, and traffic data over a wide variety of weather conditions and to use this data to assess the reliability and appropriateness of the speed limits produced by the VSL system. The first two objectives of implementing a full RWIS site upgrade and enhancement were achieved and are discussed in detail in this report. However, reconfiguring software and hardware for the project, installing power and telephone lines, and installing and calibrating sensor and traffic detection systems consumed most of the time allotted to the project. Collection of project data did not begin until July of 2001, just as this report was being written. Nonetheless, an interactive web site has been developed which employs software tools that will be used to analyze and compare the RWIS data and the traffic flow data when it is collected. The web site and its software tools are discussed in this report.

The main objective of the Fuzzy Variable Speed Limit Device (FVSLD) Project was to demonstrate th... more The main objective of the Fuzzy Variable Speed Limit Device (FVSLD) Project was to demonstrate that fuzzy logic is well-suited to the design and implementation of a variable speed limit (VSL) system dedicated to speed management on rural highways. This objective was demonstrated through the creation of a real-time fuzzy control system that could continuously display highway speeds that are appropriate to the atmospheric and road surface conditions that exist at any given time at locations of interest. The software that implements the control system was the main product of the project although a micro-controller based hardware prototype of the final fuzzy control system was also created. The geographical area of concern for the project was the I-40 corridor in rural northern Arizona. This corridor passes through a variety of geographic locations that range from desert to mountainous terrain. As a final demonstration, the completed FVSLD Project software was used to remotely display, in real-time at the district headquarters of the Arizona Department of Transportation in Flagstaff, appropriate highway speeds for three target Road Weather Information System (RWIS) sites selected along the I-40 corridor. Information provided by each of these RWIS stations was monitored and an appropriate speed limit for each location was displayed. The sites selected were the RWIS stations located at Riordan, Pine Springs, and Ash Fork.

ABSTRACT The main objective of the Fuzzy Variable Speed Limit Device (FVSLD) Project was to demon... more ABSTRACT The main objective of the Fuzzy Variable Speed Limit Device (FVSLD) Project was to demonstrate that fuzzy logic is well-suited to the design and implementation of a variable speed limit (VSL) system dedicated to speed management on rural highways. This objective was demonstrated through the creation of a real-time fuzzy control system that could continuously display highway speeds that are appropriate to the atmosphere and road surface conditions that exist at any given time at locations of interest. The software that implements the control system was the main product of the project although a micro-controller based hardware prototype of the final fuzzy control system was also created. The geographical area of concern for the project was the I-40 corridor in rural northern Arizona. This corridor passes through a variety of geographic locations that range from desert to mountainous terrain. As a final demonstration, the completed FVSLD Project software was used to remotely display, in real-time at the district headquarters of the Arizona Department of Transportation in Flagstaff, appropriate highway speeds for three target Road Weather Information System (RWIS) sites selected along the I-40 corridor. Information provided by each of these RWIS stations was monitored and an appropriate speed limit for each location was displayed. The sites selected were the RWIS stations located at Riordan, Pine Springs, and Ash Fork.

Intelligent Automation and Soft Computing, 2001