744 research outputs found
Fuzzy argumentation for trust
In an open Multi-Agent System, the goals of agents acting on behalf of their owners often conflict with each other. Therefore, a personal agent protecting the interest of a single user cannot always rely on them. Consequently, such a personal agent needs to be able to reason about trusting (information or services provided by) other agents. Existing algorithms that perform such reasoning mainly focus on the immediate utility of a trusting decision, but do not provide an explanation of their actions to the user. This may hinder the acceptance of agent-based technologies in sensitive applications where users need to rely on their personal agents. Against this background, we propose a new approach to trust based on argumentation that aims to expose the rationale behind such trusting decisions. Our solution features a separation of opponent modeling and decision making. It uses possibilistic logic to model behavior of opponents, and we propose an extension of the argumentation framework by Amgoud and Prade to use the fuzzy rules within these models for well-supported decisions
Feature Selection of Post-Graduation Income of College Students in the United States
This study investigated the most important attributes of the 6-year
post-graduation income of college graduates who used financial aid during their
time at college in the United States. The latest data released by the United
States Department of Education was used. Specifically, 1,429 cohorts of
graduates from three years (2001, 2003, and 2005) were included in the data
analysis. Three attribute selection methods, including filter methods, forward
selection, and Genetic Algorithm, were applied to the attribute selection from
30 relevant attributes. Five groups of machine learning algorithms were applied
to the dataset for classification using the best selected attribute subsets.
Based on our findings, we discuss the role of neighborhood professional degree
attainment, parental income, SAT scores, and family college education in
post-graduation incomes and the implications for social stratification.Comment: 14 pages, 6 tables, 3 figure
A novel penalty-based reduced order modelling method for dynamic analysis of joint structures
This work proposes a new reduced order modelling method to improve the computational efficiency for the dynamic simulation of a jointed structures with localized contact friction non-linearities. We reformulate the traditional equation of motion for a joint structure by linearising the non-linear system on the contact interface and augmenting the linearised system by introducing an internal non-linear penalty variable. The internal variable is used to compensate the possible non-linear effects from the contact interface. Three types of reduced basis are selected for the Galerkin projection, namely, the vibration modes (VMs) of the linearised system, static modes (SMs) and also the trial vector derivatives (TVDs) vectors. Using these reduced basis, it would allow the size of the internal variable to change correspondingly with the number of active non-linear DOFs. The size of the new reduced order model therefore can be automatically updated depending on the contact condition during the simulations. This would reduce significantly the model size when most of the contact nodes are in a stuck condition, which is actually often the case when a jointed structure vibrates. A case study using a 2D joint beam model is carried out to demonstrate the concept of the proposed method. The initial results from this case study is then compared to the state of the art reduced order modeling
Odontogenic keratocysts located in the buccal mucosa : a description of two cases and review of the literature
Odontogenic keratocysts make up 4%–12% of all odontogenic cysts. Most cysts are sporadic but sometimes they arise in the context of basal cell nevus syndrome (Gorlin syndrome). Most odontogenic keratocysts arise in the posterior region of the mandible, but they can occur anywhere in the jaw. In rare instances, they are located peripherally in the gingiva. Even more rare, they are found in the soft tissues of the mouth. There have been a few case reports and small case series of such peripheral odontogenic keratocysts. Some controversy exists as to whether these truly represent a peripheral counterpart of the intraosseous odontogenic keratocysts and if their origin is at all odontogenic. We hereby present two cases of peripheral odontogenic keratocysts, both being located in the soft tissue of the buccal mucosa, and review the literature on peripheral odontogenic keratocysts
Comparison of preprocessing techniques to reduce nontissue-related variations in hyperspectral reflectance imaging
Significance: Hyperspectral reflectance imaging can be used in medicine to identify tissue types, such as tumor tissue. Tissue classification algorithms are developed based on, e.g., machine learning or principle component analysis. For the development of these algorithms, data are generally preprocessed to remove variability in data not related to the tissue itself since this will improve the performance of the classification algorithm. In hyperspectral imaging, the measured spectra are also influenced by reflections from the surface (glare) and height variations within and between tissue samples.Aim: To compare the ability of different preprocessing algorithms to decrease variations in spectra induced by glare and height differences while maintaining contrast based on differences in optical properties between tissue types.Approach: We compare eight preprocessing algorithms commonly used in medical hyperspectral imaging: standard normal variate, multiplicative scatter correction, min-max normalization, mean centering, area under the curve normalization, single wavelength normalization, first derivative, and second derivative. We investigate conservation of contrast stemming from differences in: blood volume fraction, presence of different absorbers, scatter amplitude, and scatter slope-while correcting for glare and height variations. We use a similarity metric, the overlap coefficient, to quantify contrast between spectra. We also investigate the algorithms for clinical datasets from the colon and breast.Conclusions: Preprocessing reduces the overlap due to glare and distance variations. In general, the algorithms standard normal variate, min-max, area under the curve, and single wavelength normalization are the most suitable to preprocess data used to develop a classification algorithm for tissue classification. The type of contrast between tissue types determines which of these four algorithms is most suitable
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