17 research outputs found
Semidefinite Representation of the -Ellipse
The -ellipse is the plane algebraic curve consisting of all points whose
sum of distances from given points is a fixed number. The polynomial
equation defining the -ellipse has degree if is odd and degree
if is even. We express this polynomial equation as
the determinant of a symmetric matrix of linear polynomials. Our representation
extends to weighted -ellipses and -ellipsoids in arbitrary dimensions,
and it leads to new geometric applications of semidefinite programming.Comment: 16 pages, 5 figure
Investigating a Hybrid Metaheuristic For Job Shop Rescheduling
Previous research has shown that artificial immune systems can be used to
produce robust schedules in a manufacturing environment. The main goal is to
develop building blocks (antibodies) of partial schedules that can be used to
construct backup solutions (antigens) when disturbances occur during
production. The building blocks are created based upon underpinning ideas from
artificial immune systems and evolved using a genetic algorithm (Phase I). Each
partial schedule (antibody) is assigned a fitness value and the best partial
schedules are selected to be converted into complete schedules (antigens). We
further investigate whether simulated annealing and the great deluge algorithm
can improve the results when hybridised with our artificial immune system
(Phase II). We use ten fixed solutions as our target and measure how well we
cover these specific scenarios
Corporate governance data of 6 Asian economies (2010–2017)
This article contains firm-level data on 1) aggregated corporate governance score, and 2) financial data for the period 2010–2017. The study includes 626 companies from 6 Asian countries: China, India, Indonesia, Japan, South Korea and Thailand. Aggregated corporate governance score is calculated using 13 firm-level attributes: board size, board independence, CEO duality, board meeting attendance, independence of audit committee, auditor ratification, independence of compensation committee, independence of nomination committee, shareholder-approved poison pill, dual class unequal voting rights of common shares, staged board, diversity of board and board duration. Finally, six firm-level financial data are included
The paradoxical success of fuzzy logic
Fuzzy logic methods have been used successfully in many real-world applications, but the foundations of fuzzy logic remain under attack. Taken together, these two facts constitute a paradox. A second paradox is that almost all of the successful fuzzy logic applications are embedded controllers, while most of the theoretical papers on fuzzy methods deal with knowledge representation and reasoning. I hope to resolve these paradoxes by identifying which aspects of fuzzy logic render it useful in practice, and which aspects are inessential. My conclusions are based on a mathematical result, on a survey of literature on the use of fuzzy logic in heuristic control and in expert systems, and on practical experience in developing expert systems