A distributed agent architecture for real-time knowledge-based systems: Real-time expert systems project, phase 1

We propose a distributed agent architecture (DAA) that can support a variety of paradigms based on both traditional real-time computing and artificial intelligence. DAA consists of distributed agents that are classified into two categories: reactive and cognitive. Reactive agents can be implemented directly in Ada to meet hard real-time requirements and be deployed on on-board embedded processors. A traditional real-time computing methodology under consideration is the rate monotonic theory that can guarantee schedulability based on analytical methods. AI techniques under consideration for reactive agents are approximate or anytime reasoning that can be implemented using Bayesian belief networks as in Guardian. Cognitive agents are traditional expert systems that can be implemented in ART-Ada to meet soft real-time requirements. During the initial design of cognitive agents, it is critical to consider the migration path that would allow initial deployment on ground-based workstations with eventual deployment on on-board processors. ART-Ada technology enables this migration while Lisp-based technologies make it difficult if not impossible. In addition to reactive and cognitive agents, a meta-level agent would be needed to coordinate multiple agents and to provide meta-level control

Toward the efficient implementation of expert systems in Ada

Here, the authors describe Ada language issues encountered during the development of ART-Ada, an expert system tool for Ada deployment. ART-Ada is being used to implement several expert system applications for the Space Station Freedom and the U.S. Air Force. Additional information is given on dynamic memory allocation

Ada issues in implementing ART-Ada

Due to the Ada mandate of a number of government agencies, interest in deploying expert systems such as Ada has increased. Recently, several Ada-based expert system tools have been developed. According to a recent benchmark report, these tools do not perform as well as similar tools written in C. While poorly implemented Ada compilers contribute to the poor benchmark result, some fundamental problems of the Ada language itself have been uncovered. Here, the authors describe Ada language issues encountered during the deployment of ART-Ada, an expert system tool for Ada deployment. ART-Ada is being used to implement several prototype expert systems for the Space Station Freedom and the U.S. Air Force

Stressed Out on Four Continents: Time Crunch or Yuppie Kvetch?

Social commentators have pointed to problems of women workers who face time stress' an absence of sufficient time to accomplish all their tasks. An economic theory views time stress as reflecting how tightly the time constraint binds households. Time stress will be more prevalent in households with higher incomes and whose members work longer in the market or on required' homework. Evidence from Australia, Canada, Germany, Korea and the United States corroborates this view. Adults in higher-income households perceive more time stress for the same amount of time spent in market work and household work. The importance of higher full incomes in generating time stress is not small, particularly in North America much is yuppie kvetch.' While time stress is most prevalent among working wives, a decomposition suggests that women would perceive more time stress than men even if both worked the same number of hours in the market and at home.

Deploying expert systems in Ada

As the Department of Defense Ada mandate begins to be enforced actively, interest in deploying expert systems in Ada has increased. A prototype Ada based expert system tool is introduced called ART/Ada. This prototype was built to support research into the language and operational issues of expert systems in Ada. ART/Ada allows applications of a conventional expert system tool called ART-IM (Automated Reasoning Tool for Information Management) to be deployed in various Ada environments with efficient use of time and space. ART-IM, a C-based expert system tool, is used to generate Ada source code which is compiled and linked with an Ada base inference engine to produce an Ada executable image. ART/Ada will be used to implement several prototype expert systems for the Space Station Freedom Program testbeds

ART-Ada: An Ada-based expert system tool

The Department of Defense mandate to standardize on Ada as the language for software systems development has resulted in increased interest in making expert systems technology readily available in Ada environments. NASA's Space Station Freedom is an example of the large Ada software development projects that will require expert systems in the 1990's. Another large scale application that can benefit from Ada based expert system tool technology is the Pilot's Associate (PA) expert system project for military combat aircraft. Automated Reasoning Tool (ART) Ada, an Ada Expert system tool is described. ART-Ada allow applications of a C-based expert system tool called ART-IM to be deployed in various Ada environments. ART-Ada is being used to implement several prototype expert systems for NASA's Space Station Freedom Program and the U.S. Air Force

ART-Ada design project, phase 2

Interest in deploying expert systems in Ada has increased. An Ada based expert system tool is described called ART-Ada, which was built to support research into the language and methodological issues of expert systems in Ada. ART-Ada allows applications of an existing expert system tool called ART-IM (Automated Reasoning Tool for Information Management) to be deployed in various Ada environments. ART-IM, a C-based expert system tool, is used to generate Ada source code which is compiled and linked with an Ada based inference engine to produce an Ada executable image. ART-Ada is being used to implement several expert systems for NASA's Space Station Freedom Program and the U.S. Air Force

Aggregate Impacts of a Gift of Time

How would people spend additional time if confronted by permanent declines in market work? We examine the impacts of cuts in legislated standard hours that raised employers' overtime costs in Japan around 1990 and Korea in the early 2000s. Using time-diaries from before and after these shocks, we show that these shocks were effective – per-capita hours of market work declined discretely. The economy-wide drops in market work were reallocated solely to leisure and personal maintenance. In the absence of changing household technology a permanent time gift leads to no increase in time spent in household production by the average individual.time use, household production, demand shock, macroeconomic effects

Aggregate Impacts of a Gift of Time

How would people spend additional time if confronted by permanent declines in market work? We examine the impacts of cuts in legislated standard hours that raised employers’ overtime costs in Japan around 1990 and Korea in the early 2000s. Using time-diaries from before and after these shocks, we show that these shocks were effective—per-capita hours of market work declined discretely. The economy-wide drops in market work were reallocated solely to leisure and personal maintenance. In the absence of changing household technology a permanent time gift leads to no increase in time spent in household production by the average individual.