Monitoring Teams by Overhearing: A Multi-Agent Plan-Recognition Approach

Recent years are seeing an increasing need for on-line monitoring of teams of cooperating agents, e.g., for visualization, or performance tracking. However, in monitoring deployed teams, we often cannot rely on the agents to always communicate their state to the monitoring system. This paper presents a non-intrusive approach to monitoring by 'overhearing', where the monitored team's state is inferred (via plan-recognition) from team-members' routine communications, exchanged as part of their coordinated task execution, and observed (overheard) by the monitoring system. Key challenges in this approach include the demanding run-time requirements of monitoring, the scarceness of observations (increasing monitoring uncertainty), and the need to scale-up monitoring to address potentially large teams. To address these, we present a set of complementary novel techniques, exploiting knowledge of the social structures and procedures in the monitored team: (i) an efficient probabilistic plan-recognition algorithm, well-suited for processing communications as observations; (ii) an approach to exploiting knowledge of the team's social behavior to predict future observations during execution (reducing monitoring uncertainty); and (iii) monitoring algorithms that trade expressivity for scalability, representing only certain useful monitoring hypotheses, but allowing for any number of agents and their different activities to be represented in a single coherent entity. We present an empirical evaluation of these techniques, in combination and apart, in monitoring a deployed team of agents, running on machines physically distributed across the country, and engaged in complex, dynamic task execution. We also compare the performance of these techniques to human expert and novice monitors, and show that the techniques presented are capable of monitoring at human-expert levels, despite the difficulty of the task

Towards Flexible Teamwork

Many AI researchers are today striving to build agent teams for complex, dynamic multi-agent domains, with intended applications in arenas such as education, training, entertainment, information integration, and collective robotics. Unfortunately, uncertainties in these complex, dynamic domains obstruct coherent teamwork. In particular, team members often encounter differing, incomplete, and possibly inconsistent views of their environment. Furthermore, team members can unexpectedly fail in fulfilling responsibilities or discover unexpected opportunities. Highly flexible coordination and communication is key in addressing such uncertainties. Simply fitting individual agents with precomputed coordination plans will not do, for their inflexibility can cause severe failures in teamwork, and their domain-specificity hinders reusability. Our central hypothesis is that the key to such flexibility and reusability is providing agents with general models of teamwork. Agents exploit such models to autonomously reason about coordination and communication, providing requisite flexibility. Furthermore, the models enable reuse across domains, both saving implementation effort and enforcing consistency. This article presents one general, implemented model of teamwork, called STEAM. The basic building block of teamwork in STEAM is joint intentions (Cohen & Levesque, 1991b); teamwork in STEAM is based on agents' building up a (partial) hierarchy of joint intentions (this hierarchy is seen to parallel Grosz & Kraus's partial SharedPlans, 1996). Furthermore, in STEAM, team members monitor the team's and individual members' performance, reorganizing the team as necessary. Finally, decision-theoretic communication selectivity in STEAM ensures reduction in communication overheads of teamwork, with appropriate sensitivity to the environmental conditions. This article describes STEAM's application in three different complex domains, and presents detailed empirical results.Comment: See http://www.jair.org/ for an online appendix and other files accompanying this articl

Review of Mobile tower radiation effects on Human and Mitigation techniques

All over the world there has been rapid increase in the mobile phone users . mobile phones are popular as they permit people to make and maintain constant and continuous communication without affecting their liberty of lifestyle . As usage of mobile phone is increasing, demand for seamless service is also gets increase and it puts pressure on the service provider . for fulfilling this demand supporting infrastructure is required .To strengthen infrastructure , service provider requires to install more mobile phone tower . Enormous installation of the mobile phone tower throughout the world raised the health concern of high electromagnetic radiation in the area near to these towers. This brings forward the need to revise the radiation level, their impact on the public health and mitigation techniques for radiations . DOI: 10.17762/ijritcc2321-8169.15024

THE SINGLE INDEX MARKET MODEL IN AGRICULTURE

This study illustrates the differences in empirical results due to data measurements and estimating procedures when applying the single index market model in agriculture. Gross and net return betas along with systematic and unsystematic risk proportions are estimated and found to be different. The stochastic coefficients model is used to show the difference in beta-risk estimates compared with the traditional fixed coefficients OLS procedure. A third estimating technique, weighted least squares/Prais Winsten method, is also proposed.Research Methods/ Statistical Methods,

Robust Agent Teams via Socially-Attentive Monitoring

Agents in dynamic multi-agent environments must monitor their peers to execute individual and group plans. A key open question is how much monitoring of other agents' states is required to be effective: The Monitoring Selectivity Problem. We investigate this question in the context of detecting failures in teams of cooperating agents, via Socially-Attentive Monitoring, which focuses on monitoring for failures in the social relationships between the agents. We empirically and analytically explore a family of socially-attentive teamwork monitoring algorithms in two dynamic, complex, multi-agent domains, under varying conditions of task distribution and uncertainty. We show that a centralized scheme using a complex algorithm trades correctness for completeness and requires monitoring all teammates. In contrast, a simple distributed teamwork monitoring algorithm results in correct and complete detection of teamwork failures, despite relying on limited, uncertain knowledge, and monitoring only key agents in a team. In addition, we report on the design of a socially-attentive monitoring system and demonstrate its generality in monitoring several coordination relationships, diagnosing detected failures, and both on-line and off-line applications

Now I.T.’s “Personal”: Offshoring and the Shifting Skill Composition of the US Information Technology Workforce

We combine new offshoring and IT workforce micro-data to investigate how an increase in the offshore supply of IT workers has affected the composition of the US IT workforce. We find that at firms with offshore captive IT centers, the relative demand for onshore IT workers in occupations involving tasks that can be traded over computer networks, such as those requiring little personal communication or hands-on interaction with US-based objects, fell by about 8% over the last decade. By comparison, relative demand for workers in those occupations rose by about 3% in firms that were not offshoring. Our second finding is that hourly IT workers are more likely than full-time workers to be employed in occupations requiring tradable tasks, and that the relative demand for hourly IT workers is about 2-3% lower in offshoring firms. We discuss the implications of our findings for IT workers, policy makers, educators, and managers

Now IT\u27s Personal: Offshoring and the Shifting Skill Composition of the U.S. Information Technology Workforce

We combine new information technology (IT) offshoring and IT workforce microdata to investigate how the use of IT offshore captive centers is affecting the skill composition of the U.S. onshore IT workforce. The analysis is based on the theory that occupations involving tasks that are “tradable,” such as tasks that require little personal communication or hands-on interaction with U.S.-based objects, are vulnerable to being moved offshore. Consistent with this theory, we find that firms that have offshore IT captive centers have 8% less of their onshore IT workforce involved in tradable occupations; those without offshore captive centers have increased the proportion of onshore employment in these same occupations by 3%. In addition, we find that hourly IT workers (e.g., IT contractors) are disproportionately employed in tradable jobs, and their onshore employment is 2%–3% lower in firms with offshore captive centers. These findings persist after considering different measures of employment composition, including controls for human capital, firm performance, domestic outsourcing, and whether firms choose to build or buy software. Instrumental variables and corroborating regressions suggest that our estimates are conservative—the magnitude of the effect generally rises after accounting for reverse causality and measurement error

JOB HOPPING, KNOWLEDGE SPILLOVERS, AND REGIONAL RETURNS TO INFORMATION TECHNOLOGY INVESTMENTS

We show that substantial regional differences in returns to information technology (IT) investments by US firms are attributable in part to knowledge spillovers generated by the movements of IT workers among firms. We use a newly developed source of employee micro-data with employer identifiers and location information to model IT workers’ mobility patterns. Access to an external IT pool one standard deviation larger than the mean is associated with a 20% increase in the output elasticity of own IT investment. We discuss implications for managers and for policy makers

Visual Cryptography and Steganography Methods - Review

In today’s information era information hiding becomes very much important as people transmits the information as innocent as credit card to online stores and as dangerous as terrorist plot to hijackers. The art of information hiding receive attention of the researchers. This paper provides a review of two methods – Visual Cryptography and Steganography for secure communication via a common communication channel. DOI: 10.17762/ijritcc2321-8169.16043

The Extroverted Firm: How External Information Practices Affect Innovation and Productivity

We gather detailed data on organizational practices and information technology (IT) use at 253 firms to examine the hypothesis that external focus—the ability of a firm to detect and therefore respond to changes in its external operating environment—increases returns to IT, especially when combined with decentralized decision making. First, using survey-based measures, we find that external focus is correlated with both organizational decentralization, and IT investment. Second, we find that a cluster of practices including external focus, decentralization, and IT is associated with improved product innovation capabilities. Third, we develop and test a three-way complementarities model that indicates that the combination of external focus, decentralization, and IT is associated with significantly higher productivity in our sample. We also introduce a new set of instrumental variables representing barriers to IT-related organizational change and find that our results are robust when we account for the potential endogeneity of organizational investments. Our results may help explain why firms that operate in information-rich environments such as high-technology clusters or areas with high worker mobility have experienced especially high returns to IT investment and suggest a set of practices that some managers may be able to use to increase their returns from IT investments.Massachusetts Institute of Technology. Center for Digital BusinessNational Science Foundation (U.S.) (Grant IRI-9733877