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Relevant Attributes (relevant + attribute)
Selected AbstractsA systematic iterative procedure for determining granulator operating parametersAICHE JOURNAL, Issue 9 2006Ka Y. Fung Abstract A systematic iterative procedure is presented for determining granulator operating parameters to produce granules with desired product attributes. These include mean granule size, size distribution, porosity, strength, and spatial distribution of the constituent components. After selecting the equipment and binder, a preliminary experiment is performed to determine base case results, which usually do not match the desired attributes. The final product is obtained using an iterative procedure with both analyses and experiments. The qualitative analysis identifies the operating parameters that can effect changes to the off-spec attribute. This is followed by a quantitative analysis,based on simple physically based mathematical models in the form of sensitivity analysis,that determines the parameter that has the greatest effect on the relevant attribute. Experiments with the modified formulation and operating conditions are conducted and the entire procedure is repeated until the desired product is obtained. A system with lactose and starch using hydroxypropyl cellulose as binder in an agitated fluidized bed granulator (Hosokawa Micron AgglomasterÔ) is used to illustrate this procedure. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] Discovering Maximal Generalized Decision Rules Through Horizontal and Vertical Data ReductionCOMPUTATIONAL INTELLIGENCE, Issue 4 2001Xiaohua Hu We present a method to learn maximal generalized decision rules from databases by integrating discretization, generalization and rough set feature selection. Our method reduces the data horizontally and vertically. In the first phase, discretization and generalization are integrated and the numeric attributes are discretized into a few intervals. The primitive values of symbolic attributes are replaced by high level concepts and some obvious superfluous or irrelevant symbolic attributes are also eliminated. Horizontal reduction is accomplished by merging identical tuples after the substitution of an attribute value by its higher level value in a pre-defined concept hierarchy for symbolic attributes, or the discretization of continuous (or numeric) attributes. This phase greatly decreases the number of tuples in the database. In the second phase, a novel context-sensitive feature merit measure is used to rank the features, a subset of relevant attributes is chosen based on rough set theory and the merit values of the features. A reduced table is obtained by removing those attributes which are not in the relevant attributes subset and the data set is further reduced vertically without destroying the interdependence relationships between classes and the attributes. Then rough set-based value reduction is further performed on the reduced table and all redundant condition values are dropped. Finally, tuples in the reduced table are transformed into a set of maximal generalized decision rules. The experimental results on UCI data sets and a real market database demonstrate that our method can dramatically reduce the feature space and improve learning accuracy. [source] Developing a relativities approach to valuing the prevention of non-fatal work-related accidents and ill healthHEALTH ECONOMICS, Issue 11 2005Jonathan Karnon Abstract The aim of the current explorative study is to define and test a process for the valuation of the benefits associated with the prevention of non-fatal work-related accidents and ill health. A relativities approach is adopted, and monetary values for the prevention of three forms of work-related illness are estimated. The approach involves describing relevant attributes of alternative events (accidents or occurrences of ill health), their causes, the characteristics of the relevant working population, and the number of events that are avoidable, and asking respondents to make pair wise choices between alternatives options for prevention. Indirect monetary valuations are obtained against a peg event for which a reliable valuation exists (road deaths). A series of discussion groups were held to identify relevant factors affecting potential valuations and to test the presentation of information. The predicted magnitude of responses for three-case study events (and road deaths) was estimated in a pilot study. These preliminary stages informed the final survey instrument that described five attributes in addition to a statement of the event and occupation, and the likely intervention effect, which was administered by post. Based on a small sample, the results show that virtually all respondents passed the inserted consistency test. The median respondent altered their choice according to the number of events avoided for all three comparisons, such that the estimated valuations appear sensible. Potential amendments are suggested, but the general relativities approach warrants further investigation for the valuation of non-fatal work-related accidents and ill health. Copyright © 2005 John Wiley & Sons, Ltd. [source] A fuzzy preference-ranking model for a quality evaluation of hospital web sitesINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 11 2006R. Ufuk Bilsel This article presents a quality evaluation model for measuring the performance of hospital Web sites. The model is developed on the basis of a conceptual framework, which consists of seven major e-service quality dimensions, including tangibles, reliability, responsiveness, confidence, empathy, quality of information, and integration of communication issues of Web sites. The dimensions and their associated attributes are first obtained from published articles in the health care and information technology literature and then adapted according to the suggestions of related domain experts. Two multicriteria decision-making methods are used in the evaluation procedure. Determined Web site evaluation dimensions and their relevant attributes are weighted using the Analytic Hierarchy Process (AHP) method. Vagueness in some stages of the evaluation required the incorporation of fuzzy numbers in the assessment process. Both fuzzy and crisp data are then synthesized using the fuzzy PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluation) ranking method. The model is applied initially to measure the performance of the Web sites of Turkish hospitals. This study should be of interest to health care and technology practitioners and researchers, as the findings shed light on the further development of performance measurements for hospital Web sites. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 1181,1197, 2006. [source] Random error reduction in analytic hierarchies: a comparison of holistic and decompositional decision strategiesJOURNAL OF BEHAVIORAL DECISION MAKING, Issue 3 2001Osvaldo F. Morera Abstract The principle of ,divide and conquer' (DAC) suggests that complex decision problems should be decomposed into smaller, more manageable parts, and that these parts should be logically aggregated to derive an overall value for each alternative. Decompositional procedures have been contrasted with holistic evaluations that require decision makers to simultaneously consider all the relevant attributes of the alternatives under consideration (Fischer, 1977). One area where decompositional procedures have a clear advantage over holistic procedures is in the reduction of random error (Ravinder, 1992; Ravinder and Kleinmuntz, 1991; Kleinmuntz, 1990). Adopting the framework originally developed by Ravinder and colleagues, this paper details the results of a study of the random error variances associated with another popular multi-criteria decision-making technique, the Analytic Hierarchy Process (AHP); (Saaty, 1977, 1980), as well as the random error variances of a holistic version of the Analytic Hierarchy Process (Jensen, 1983). In addition, data concerning various psychometric properties (e.g. the convergent validity and temporal stability) and values of AHP inconsistency are reported for both the decompositional and holistic evaluations. The results of the study show that the Ravinder and Kleinmuntz (1991) error-propagation framework extends to the AHP and decompositional AHP judgments are more consistent than their holistic counterparts. Copyright © 2001 John Wiley & Sons, Ltd. [source] Patch occupancy of North American mammals: is patchiness in the eye of the beholder?JOURNAL OF BIOGEOGRAPHY, Issue 8 2003Robert K. Swihart Abstract Aim Intraspecific variation in patch occupancy often is related to physical features of a landscape, such as the amount and distribution of habitat. However, communities occupying patchy environments typically exhibit non-random distributions in which local assemblages of species-poor patches are nested subsets of assemblages occupying more species-rich patches. Nestedness of local communities implies interspecific differences in sensitivity to patchiness. Several hypotheses have been proposed to explain interspecific variation in responses to patchiness within a community, including differences in (1) colonization ability, (2) extinction proneness, (3) tolerance to disturbance, (4) sociality and (5) level of adaptation to prevailing environmental conditions. We used data on North American mammals to compare the performance of these ,ecological' hypotheses and the ,physical landscape' hypothesis. We then compared the best of these models against models that scaled landscape structure to ecologically relevant attributes of individual species. Location North America. Methods We analysed data on prevalence (i.e. proportion of patches occupied in a network of patches) and occupancy for 137 species of non-volant mammals and twenty networks consisting of four to seventy-five patches. Insular and terrestrial networks exhibited significantly different mean levels of prevalence and occupancy and thus were analysed separately. Indicator variables at ordinal and family levels were included in models to correct for effects caused by phylogeny. Akaike's information criterion was used in conjunction with ordinary least squares and logistic regression to compare hypotheses. Results A patch network's physical structure, indexed using patch area and isolation, received the greatest support among models predicting the prevalence of species on insular networks. Niche breadth (diet and habitat) received the greatest support for predicting prevalence of species occupying terrestrial networks. For both insular and terrestrial systems, physical features (patch area and isolation) received greater support than any of the ecological hypotheses for predicting species occupancy of individual patches. For terrestrial systems, scaling patch area by its suitability to a focal species and by individual area requirements of the species, and scaling patch isolation by species-specific dispersal ability and niche breadth, resulted in models of patch occupancy that were superior to models relying solely on physical landscape features. For all selected models, unexplained levels of variation were high. Main conclusions Stochasticity dominated the systems we studied, indicating that random events are probably quite important in shaping local communities. With respect to deterministic factors, our results suggest that forces affecting species prevalence and occupancy may differ between insular and terrestrial systems. Physical features of insular systems appeared to swamp ecological differences among species in determining prevalence and occupancy, whereas species with broad niches were disproportionately represented in terrestrial networks. We hypothesize that differential extinction over long time periods in highly variable networks has driven nestedness of mammalian communities on islands, whereas differential colonization over shorter time-scales in more homogeneous networks probably governed the local structure of terrestrial communities. Our results also demonstrate that integration of a species' ecological traits with physical features of a patch network is superior to reliance on either factor separately when attempting to predict the species' probability of patch occupancy in terrestrial systems. [source] | ||||||||||