9,590 research outputs found
Eight Things you should Know about Open Source Integrated Library Systems.
Open source library management systems are free alternative to costly commercial library systems. It helps to automate library functions and give a tremendous savings on library automation expenses. User ’s participation in all stages of software project ensures the development of the features that the library really wants. Lack of awareness and knowledge in open source technology among library professionals restrict wide adoption of open source library management system. This article gives an insight into the use and maintenance of open source library management systems
LEARNING ALGORITHMS FOR MARKOV DECISION PROCESSES
We propose various computational schemes for solving Partially Observable
Markov Decision Processes with the finite stage additive cost and infinite
horizon discounted cost criterion. Error bounds for the corresponding algorithms
are given and it is further shown that at the expense of more computational
effort the Partially Observable Markov Decision Problem (POMDP) can be solved
as closely to the optimal as desired.
It is well known that a sufficient statistic for taking the best action at any time for
the POMDP is the aposteriori probability distribution on the underlying states, given
all the past history, and that this can be updated recursively. We prove that the finite
stage optimal costs as well as the optimal cost for the infinite horizon discounted
cost problem are both Lipschitz continuous (with domain the unit simplex of probability
distributions over the underlying states) and gives bounds for the Lipschitz constant.
We use these bounds to provide error bounds for computational algorithms for solving
POMDPs.
We extend the almost sure convergence result of a very general stochastic approximation
algorithm to the case when the underlying Markov process exhibits periodicity. This result
is used to extend the proof of convergence of Temporal Difference (TD) reinforcement learning
schemes with linear function approximation for Markov Cost processes in order to estimate the
cost to go function for the discounted cost criterion, and the differential cost function for the
average cost criterion, respectively.
Adaptive control of Markov Decision Problems (MDPs) is a problem in which a full knowledge
of the system parameters, namely transition probabilities as well as the distribution of the
immediate costs, are not available apriori. We give direct adaptive control schemes for
infinite horizon discounted cost and average cost MDPs. Approximate Policy Iteration
using on-line TD schemes for policy evaluation is detailed for the discounted cost and
average cost criteria.
Possible extensions of direct adaptive control schemes to the POMDP framework are
discussed.
Auxiliary results relevant to the core results of the dissertation are stated
and proved in the appendices. In particular an efficient discretization scheme
for the finite dimensional unit simplex is given. Some general error bounds for
MDPs are also given. Also TD schemes for learning in Stochastic Shortest Path
problems (SSP) are discussed
Lessons from the pandemic: the need for new tools for risk and outbreak communication
The influenza pandemic of 2009 revealed shortcomings in the existing guidelines for risk and outbreak communication. Concepts such as building trust proved hard to achieve in practice, whereas other issues such as communicating through the internet and coping with the political fallout of disease outbreaks are not dealt with in existing guidelines. This article surveys the current guidelines and makes recommendations for additional tools and guidelines to be developed in four areas: integrating long-term behavior change models with outbreak communications; research to develop a better understanding of communicating through the internet; research to understand how to use communications to build trust; and developing guidelines and principles to understand the political nature of disease outbreaks
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Modelling information usage and decision processes in new product introductions : an information-processing perspective.
The objective of this study is to understand the problem solving process used in new product introductions, and other unstructured business problems. I hope this understanding will contribute to improved decision support systems. Based on Cognitive psychology theories (in particular, Anderson, 1983, 1987), a set of propositions were outlined and investigated by using a computer model. One application of the expert system shell, used here, is to try to model the expert\u27s knowledge. The shell is used to develop a system that simulates the expert\u27s approach to problem solving. The differences between this application and expert system development, are: (i) the focus is on trying to understand the mind of the expert, instead of trying to replace him; and (ii) the problem area is ill-structured, instead of narrow and well-defined. The introduction of new products into markets is an example of an ill-structured problem, in a business setting. In particular, identifying opportunities is to create new products--their future growth and competitiveness often depends on this. The method adopted, computer simulation, has both advantages and limitations. The advantages include: (i) in-depth analysis of the problem-solving process; (ii) operationalizing the theory; and (iii) producing a program that can act as a research vehicle for future projects. The limitations are: (i) small sample size; (ii) lack of clear-cut validation procedures; and (iii) dependence on shell features. The findings, for the most part, supported the propositions (i) The expert model clearly had more procedural knowledge than the textbook model. This supports the proceduralization theory of skill acquisition. (ii) Reasoning by analogy was used by both expert and novices. The use of weak methods by the expert does not support the theory. (iii) The expert adopted a forward reasoning strategy within a task agenda. This supports the hierarchical goal structure theory of Anderson. (iv) The use of soft information was also observed
Evaluating the Virtual Management Information Systems (MIS) Classroom
This paper outlines techniques for an active learning environment in a virtual MIS classroom, as well as a comparison of outcomes in that distance learning class with a regular, live, MIS class. These techniques included discussions, small group projects and cooperative work supported by technology such as chat sessions, e-mail and bulletin boards. Feedback to students was improved through the use of an online grade book and e-mail. Outcomes were measured in terms of grades for participation, exercises, assignments, tests and the overall grade. There were no significant differences in outcomes. The paper also presents the results of a survey measuring students\u27 experiences with the virtual class. Students were generally very positive about the quality of the learning experience. Teaching a distance learning class using active learning techniques is a difficult and time-consuming enterprise
Electromagnetic Energy, Momentum, and Angular Momentum in an Inhomogeneous Linear Dielectric
In a previous work, Optics Communications 284 (2011) 2460--2465, we
considered a dielectric medium with an anti-reflection coating and a spatially
uniform index of refraction illuminated at normal incidence by a
quasimonochromatic field. Using the continuity equations for the
electromagnetic energy density and the Gordon momentum density, we constructed
a traceless, symmetric energy--momentum tensor for the closed system. In this
work, we relax the condition of a uniform index of refraction and consider a
dielectric medium with a spatially varying index of refraction that is
independent of time, which essentially represents a mechanically rigid
dielectric medium due to external constraints. Using continuity equations for
energy density and for Gordon momentum density, we construct a symmetric
energy--momentum matrix, whose four-divergence is equal to a generalized
Helmholtz force density four-vector. Assuming that the energy-momentum matrix
has tensor transformation properties under a symmetry group of space-time
coordinate transformations, we derive the global conservation laws for the
total energy, momentum, and angular momentum.Comment: added publication informatio
Is There A Caste System In India?
American news media as well as American textbooks, both college and secondary schools, present India as a unique society because it practices the caste system, which is then described in terms of its presumed traditional characteristics. Americans thus learn to picture the Indian society as extremely static and assume that the caste system still continues in its traditional form. The fact is that even in traditional times, the caste system never existed as it was theoretically supposed to operate. In modern India, the caste system exists, but not as westerners generally conceive of it
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