975 resultados para partial knowledge


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Partial cDNA sequences of myosin V from rainbow trout Oncorhynchus mykiss were analyzed and showed high similarity to MVa from other vertebrates. Phylogenetic analysis has shown that events resulting in the formation of paralogous copies of myosin Va, Vb, and Vc occurred before the divergence of vertebrates into different classes. Expression analysis of myosin Va, Vb, and Vc in different O. mykiss tissues revealed MVa exclusively expressed in hypophysis and brain whereas Vb and Vc were expressed in practically all tissues analyzed. The nucleotide sequence for myosin V was explored in a fish species for the first time and these results represent an important start in understanding the organization, evolution, and expression of myosins in early vertebrates. The data presented here represent contributions to the knowledge of rainbow trout genome. A better understanding of this economically important species could assist in development of improved strains of this fish for aquaculture.

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The extensive use of buffalo in agriculture, especially in developing countries, begs for genetic resources to evaluate and improve traits important to local and regional economies. Brazil presents the largest water buffalo populations in the New World, with 1 1 million heads including swamp and river types. To design rational breeding strategies for optimum utilization and conservation of available genetic variability in the Brazilian buffalo's population, it is essential to understand their genetic architecture and relationship among various breeds. This depends, in part, on the knowledge of their genetic structure based on molecular markers like microsatellites. In the present study, we developed six enriched partial genomic libraries for river buffalo using selective hybridization methods. Genomic DNA was hybridized with six different arrays of repeat motif, 5' biotinylated - (CA)(15), (CT)(15), (AGG)(8), (GAAA)(8), (GATA)(8), (AAAAC)(8) - and bound to streptavidin coated beads. The cloning process generated a total of 1920 recombinant clones. Up to date, 487 were directly sequenced for the presence of repeats, from which 13 have been positive for presence of repeats as follows: 9 for di-nucleotide repeats, 3 for tri-nucleotide repeats and 1 for tetra-nucleotide repeat. PCR primer pairs for the isolated microsatellites are under construction to determine optimum annealing temperature. These microsatellites will be useful for studies involving phylogenetic relationships, genome mapping and genetic diversity analysis within buffalo populations worldwide.

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One common problem in all basic techniques of knowledge representation is the handling of the trade-off between precision of inferences and resource constraints, such as time and memory. Michalski and Winston (1986) suggested the Censored Production Rule (CPR) as an underlying representation and computational mechanism to enable logic based systems to exhibit variable precision in which certainty varies while specificity stays constant. As an extension of CPR, the Hierarchical Censored Production Rules (HCPRs) system of knowledge representation, proposed by Bharadwaj & Jain (1992), exhibits both variable certainty as well as variable specificity and offers mechanisms for handling the trade-off between the two. An HCPR has the form: Decision If(preconditions) Unless(censor) Generality(general_information) Specificity(specific_information). As an attempt towards evolving a generalized knowledge representation, an Extended Hierarchical Censored Production Rules (EHCPRs) system is suggested in this paper. With the inclusion of new operators, an Extended Hierarchical Censored Production Rule (EHCPR) takes the general form: Concept If (Preconditions) Unless (Exceptions) Generality (General-Concept) Specificity (Specific Concepts) Has_part (default: structural-parts) Has_property (default:characteristic-properties) Has_instance (instances). How semantic networks and frames are represented in terms of an EHCPRs is shown. Multiple inheritance, inheritance with and without cancellation, recognition with partial match, and a few default logic problems are shown to be tackled efficiently in the proposed system.

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Dimensionality reduction is employed for visual data analysis as a way to obtaining reduced spaces for high dimensional data or to mapping data directly into 2D or 3D spaces. Although techniques have evolved to improve data segregation on reduced or visual spaces, they have limited capabilities for adjusting the results according to user's knowledge. In this paper, we propose a novel approach to handling both dimensionality reduction and visualization of high dimensional data, taking into account user's input. It employs Partial Least Squares (PLS), a statistical tool to perform retrieval of latent spaces focusing on the discriminability of the data. The method employs a training set for building a highly precise model that can then be applied to a much larger data set very effectively. The reduced data set can be exhibited using various existing visualization techniques. The training data is important to code user's knowledge into the loop. However, this work also devises a strategy for calculating PLS reduced spaces when no training data is available. The approach produces increasingly precise visual mappings as the user feeds back his or her knowledge and is capable of working with small and unbalanced training sets.

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The cone penetration test (CPT), together with its recent variation (CPTU), has become the most widely used in-situ testing technique for soil profiling and geotechnical characterization. The knowledge gained over the last decades on the interpretation procedures in sands and clays is certainly wide, whilst very few contributions can be found as regards the analysis of CPT(u) data in intermediate soils. Indeed, it is widely accepted that at the standard rate of penetration (v = 20 mm/s), drained penetration occurs in sands while undrained penetration occurs in clays. However, a problem arise when the available interpretation approaches are applied to cone measurements in silts, sandy silts, silty or clayey sands, since such intermediate geomaterials are often characterized by permeability values within the range in which partial drainage is very likely to occur. Hence, the application of the available and well-established interpretation procedures, developed for ‘standard’ clays and sands, may result in invalid estimates of soil parameters. This study aims at providing a better understanding on the interpretation of CPTU data in natural sand and silt mixtures, by taking into account two main aspects, as specified below: 1)Investigating the effect of penetration rate on piezocone measurements, with the aim of identifying drainage conditions when cone penetration is performed at a standard rate. This part of the thesis has been carried out with reference to a specific CPTU database recently collected in a liquefaction-prone area (Emilia-Romagna Region, Italy). 2)Providing a better insight into the interpretation of piezocone tests in the widely studied silty sediments of the Venetian lagoon (Italy). Research has focused on the calibration and verification of some site-specific correlations, with special reference to the estimate of compressibility parameters for the assessment of long-term settlements of the Venetian coastal defences.

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OBJECTIVE The aim was to develop a delineation guideline for target definition for APBI or boost by consensus of the Breast Working Group of GEC-ESTRO. PROPOSED RECOMMENDATIONS Appropriate delineation of CTV (PTV) with low inter- and intra-observer variability in clinical practice is complex and needs various steps as: (1) Detailed knowledge of primary surgical procedure, of all details of pathology, as well as of preoperative imaging. (2) Definition of tumour localization before breast conserving surgery inside the breast and translation of this information in the postoperative CT imaging data set. (3) Calculation of the size of total safety margins. The size should be at least 2 cm. (4) Definition of the target. (5) Delineation of the target according to defined rules. CONCLUSION Providing guidelines based on the consensus of a group of experts should make it possible to achieve a reproducible and consistent definition of CTV (PTV) for Accelerated Partial Breast Irradiation (APBI) or boost irradiation after breast conserving closed cavity surgery, and helps to define it after selected cases of oncoplastic surgery.

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In computer science, different types of reusable components for building software applications were proposed as a direct consequence of the emergence of new software programming paradigms. The success of these components for building applications depends on factors such as the flexibility in their combination or the facility for their selection in centralised or distributed environments such as internet. In this article, we propose a general type of reusable component, called primitive of representation, inspired by a knowledge-based approach that can promote reusability. The proposal can be understood as a generalisation of existing partial solutions that is applicable to both software and knowledge engineering for the development of hybrid applications that integrate conventional and knowledge based techniques. The article presents the structure and use of the component and describes our recent experience in the development of real-world applications based on this approach.

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The WSIS is centrally interested in knowledge and has defined for itself a mission that is broadly humanitarian. Its development ‘talk’ is, rightly, replete with notions of equity, preserving culture, justice, human rights and so on. In incorporating such issues into knowledge society and economy discussions, WSIS has adopted a different posture towards knowledge than is seen in dominant discourses. This study analyses the dominant knowledge discourse using a large corpus of knowledge-related policy documents, discourse theory and an interrelational understanding of knowledge. I show that it is important to understand this dominant knowledge discourse because of its capacity to limit thought and action in relation to its central topic, knowledge. The results of this study demonstrate that the dominant knowledge discourse is technocratic, frequently insensitive to the humane mission at the core of the WSIS, and is based on a partial understanding of what knowledge is and how knowledge systems work. Moreover, I show that knowledge is inherently political, that the dominant knowledge discourse is politically oriented towards the concerns of business and technology, but that an emancipatory politics of knowledge is possible.

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J.L., then a 25-year-old physiotherapist, became densely amnesic following herpes simplex encephalitis. She displayed severe retrograde amnesia, category-specific semantic memory loss, and a profound anterograde amnesia affecting both verbal and visual memory. Her working memory systems were relatively spared as were most of her cognitive problem-solving abilities, but her social functioning was grossly impaired. She was able to demonstrate several previously learned physiotherapy skills, but was unable to modify her application of these procedures in accordance with patient response. She showed no memory of theoretical or propositional knowledge, and could neither plan treatment or reason clinically. Three years later, J.L. had profound impairment of anterograde and retrograde declarative memory, with relative sparing of working memory for problem solving and long-term memory of procedural skills. The theoretical and practical implications of her amnesic syndrome are discussed.

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Ontologies have become a key component in the Semantic Web and Knowledge management. One accepted goal is to construct ontologies from a domain specific set of texts. An ontology reflects the background knowledge used in writing and reading a text. However, a text is an act of knowledge maintenance, in that it re-enforces the background assumptions, alters links and associations in the ontology, and adds new concepts. This means that background knowledge is rarely expressed in a machine interpretable manner. When it is, it is usually in the conceptual boundaries of the domain, e.g. in textbooks or when ideas are borrowed into other domains. We argue that a partial solution to this lies in searching external resources such as specialized glossaries and the internet. We show that a random selection of concept pairs from the Gene Ontology do not occur in a relevant corpus of texts from the journal Nature. In contrast, a significant proportion can be found on the internet. Thus, we conclude that sources external to the domain corpus are necessary for the automatic construction of ontologies.

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This paper, addresses the problem of novelty detection in the case that the observed data is a mixture of a known 'background' process contaminated with an unknown other process, which generates the outliers, or novel observations. The framework we describe here is quite general, employing univariate classification with incomplete information, based on knowledge of the distribution (the 'probability density function', 'pdf') of the data generated by the 'background' process. The relative proportion of this 'background' component (the 'prior' 'background' 'probability), the 'pdf' and the 'prior' probabilities of all other components are all assumed unknown. The main contribution is a new classification scheme that identifies the maximum proportion of observed data following the known 'background' distribution. The method exploits the Kolmogorov-Smirnov test to estimate the proportions, and afterwards data are Bayes optimally separated. Results, demonstrated with synthetic data, show that this approach can produce more reliable results than a standard novelty detection scheme. The classification algorithm is then applied to the problem of identifying outliers in the SIC2004 data set, in order to detect the radioactive release simulated in the 'oker' data set. We propose this method as a reliable means of novelty detection in the emergency situation which can also be used to identify outliers prior to the application of a more general automatic mapping algorithm. © Springer-Verlag 2007.

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Knowledge management is a topic that crosses borders of various kinds, such as those between departments, between organisations or between countries. In this paper we will consider various issues relating to knowledge management, in the context where more than one department/organisation/country is involved. To do this, we place an emphasis on knowledge management as a process, rather than as an organisational system or, worse, as a piece of technology. This process involves trust, negotiation—and indeed some technological support. In this paper we wish to introduce the concept of ‘triangles of trust’, and to focus on where ‘the top meets the bottom’ in terms of knowledge management and organisational learning. Partial examples will be offered in support of our views, but no full and complete examples—knowledge management simply is not well enough understood or documented for that yet. Our overall conclusion is that there is no one best way to “do” knowledge management, but there are principles that ought to be applied.

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This study critically discusses findings from a research project involving four European countries. The project had two main aims. The first was to develop a systematic procedure for assessing the balance between knowledge and competencies acquired in higher, further and vocational education and the specific needs of the labor market. The second aim was to develop and test a set of meta-level quality indicators aimed at evaluating the linkages between education and employment. The project was designed to address the lack of employer input concerning the requirements of business graduates for successful workplace performance and the need for more specific industry-driven feedback to guide administrative heads at universities and personnel at quality assurance agencies in curriculum development and revision. Approach: The project was distinctive in that it combined different partners from higher education, vocational training, industry and quality assurance. Project partners designed and implemented an innovative approach, based on literature review, qualitative interviews and surveys in the four countries, in order to identify and confirm key knowledge and competency requirements. This study presents this step-by-step approach, as well as survey findings from a sample of 900 business graduates and employers. In addition, it introduces two Partial Least Squares (PLS) path models for predicting satisfaction with work performance and satisfaction with business education. Results: Survey findings revealed that employers were not very confident regarding business graduates’ abilities in key knowledge areas and in key generic competencies. In subsequent analysis, these graduate abilities were tested and identified as important predictors of employers’ satisfaction with graduates’ work performance. Conclusion: The industry-driven approach introduced in this study can serve as a guide to assist different types of educational institutions to better align study programs with changing labor market requirements. Recommendations for curriculum improvement are discussed.

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This paper describes the knowledge elicitation and knowledge representation aspects of a system being developed to help with the design and maintenance of relational data bases. The size algorithmic components. In addition, the domain contains multiple experts, but any given expert's knowledge of this large domain is only partial. The paper discusses the methods and techniques used for knowledge elicitation, which was based on a "broad and shallow" approach at first, moving to a "narrow and deep" one later, and describes the models used for knowledge representation, which were based on a layered "generic and variants" approach. © 1995.

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Recently, the interest of the automotive market for hybrid vehicles has increased due to the more restrictive pollutants emissions legislation and to the necessity of decreasing the fossil fuel consumption, since such solution allows a consistent improvement of the vehicle global efficiency. The term hybridization regards the energy flow in the powertrain of a vehicle: a standard vehicle has, usually, only one energy source and one energy tank; instead, a hybrid vehicle has at least two energy sources. In most cases, the prime mover is an internal combustion engine (ICE) while the auxiliary energy source can be mechanical, electrical, pneumatic or hydraulic. It is expected from the control unit of a hybrid vehicle the use of the ICE in high efficiency working zones and to shut it down when it is more convenient, while using the EMG at partial loads and as a fast torque response during transients. However, the battery state of charge may represent a limitation for such a strategy. That’s the reason why, in most cases, energy management strategies are based on the State Of Charge, or SOC, control. Several studies have been conducted on this topic and many different approaches have been illustrated. The purpose of this dissertation is to develop an online (usable on-board) control strategy in which the operating modes are defined using an instantaneous optimization method that minimizes the equivalent fuel consumption of a hybrid electric vehicle. The equivalent fuel consumption is calculated by taking into account the total energy used by the hybrid powertrain during the propulsion phases. The first section presents the hybrid vehicles characteristics. The second chapter describes the global model, with a particular focus on the energy management strategies usable for the supervisory control of such a powertrain. The third chapter shows the performance of the implemented controller on a NEDC cycle compared with the one obtained with the original control strategy.