930 resultados para Models for the evaluation of credibility and reputation
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MODSI is a multi-models tool for information systems modeling. A modeling process in MODSI can be driven according to three different approaches: informal, semi-formal and formal. The MODSI tool is therefore based on the linked usage of these three modeling approaches. It can be employed at two different levels: the meta-modeling of a method and the modeling of an information system.In this paper we start presenting different types of modeling by making an analysis of their particular features. Then, we introduce the meta-model defined in our tool, as well as the tool functional architecture. Finally, we describe and illustrate the various usage levels of this tool.
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This paper investigates properties of integer programming models for a class of production planning problems. The models are developed within a decision support system to advise a sales team of the products on which to focus their efforts in gaining new orders in the short term. The products generally require processing on several manufacturing cells and involve precedence relationships. The cells are already (partially) committed with products for stock and to satisfy existing orders and therefore only the residual capacities of each cell in each time period of the planning horizon are considered. The determination of production recommendations to the sales team that make use of residual capacities is a nontrivial optimization problem. Solving such models is computationally demanding and techniques for speeding up solution times are highly desirable. An integer programming model is developed and various preprocessing techniques are investigated and evaluated. In addition, a number of cutting plane approaches have been applied. The performance of these approaches which are both general and application specific is examined.
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The possibility of reducing the concentration of the working solution used in the tetrazolium test for peanut seeds (Arachis hypogaea L.) with or without seedcoats was studied. Tetrazolium solutions of different concentrations (0.05%, 0.075% and 0.1%) were tested at the temperatures of 35 and 40 degrees C, for determining the time needed for the seeds to reach proper staining. The efficiency of the selected treatments in evaluating the viability potential of the seeds was determined by comparing the results of the tetrazolium tests with those obtained by standard germination (using sand and rolled paper towel as substrata) and seedling emergence in the field tests. Staining the seeds without seedcoat in 0.05% tetrazolium solution for three hours at 40 degrees C yielded efficient results. on the other hand, reduced concentrations can be employed in the staining process of seeds with seedcoat; however, this method requires a higher consumption of tetrazolium salt, longer staining time as well as a higher ability and availability of time for embryo evaluation, since the cross-cutting of seeds is much more difficult in the presence of the seedcoat and the occurrence of damage to the outer surface of the cotyledons cannot be determined.
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This article discusses the development of a test bench and a methodology for the study of composite resin abrasive wear. To evaluate the operation of the test bench and to compare the proposed methodology with other existing ones, a study was made of the five composites most commonly used by dentists.The one-way ANOVA method and the Tukey test were used to statistically analyze the results by multiple comparisons of the groups of resins tested. Using the proposed methodology, these resins were classified in an increasing order of abrasive wear strength, as follows: Charisma (the lowest abrasive wear strength), Tetric, TPH, Herculite and Z-100 (the highest abrasive wear strength) (P < 0.05). In comparison to other methodologies, the results of the proposed methodology presented the lowest coefficient of variation. (C) 2002 Elsevier B.V. B.V. All rights reserved.
Evaluation of water and sucrose diffusion coefficients in potato tissue during osmotic concentration
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The water and sucrose effective diffusion coefficients behavior were studied in potato tubers immersed in aqueous sucrose solution, 50% (w/,A), at 27 degreesC. Water and sucrose concentration profiles were measured as function of the position for 3, 6 and 12 h of immersion. These were adjusted to a mathematical model for three components that take into account the bulk flow in a shrinking tissue and the concentration dependence of the diffusion coefficients.The binary effective coefficients were an order of magnitude lower than those for pure solutions of sucrose. These coefficients show an unusual concentration dependence. Analysis of these coefficients as functions of the concentration and position demonstrates that, cellular tissue promotes high resistance to diffusion in the tuber and also the elastic contraction of material influences the species diffusion. (C) 2003 Elsevier B.V. Ltd. All rights reserved.
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Action of auxins on the rooting of stem cuttings of kiwi (Actinidia chinensis P. cv Monty). This work studies the effects of some synthetic auxins and B in the rooting of kiwi (Actinidia chinensis Planch cv Monty) stem cuttings. The treatments used were as follows: T1 (H2O); T2 (NAA 300 ppm); T3 (IBA 300 ppm); T4 (NAA 300 ppm + B); T5 (IBA 300 ppm + B); T6 (NAA 0,5%-talc) and T7 (IBA 0,5%-talc), applied to the bases of the cuttings. These were then placed in rooting dishes with pure vermiculite in a misty nebulization chamber until collection day (120 days). The evaluation of auxin and boric acid effects on kiwi stem cuttings were made based on the following observations: 1. The percentage of rooted stem cuttings; 2. reducing sugars and total sugar analyses (in g/100 g of dry matter); and 3. tryptophan analyses (in mu g/100 mg of dry matter). The results show that summer is the best season for rooting Actinidia chinensis Planch cv Monty stem cuttings. The use of IBA talc 0,5% on the bases of the cuttings shamed positive results too.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This in vitro study evaluated the performance of visual (International Caries Detection and Assessment System [ICDAS]) and radiographic (bitewing [BW]) examinations for occlusal caries detection and their associations with treatment decision (TD). Permanent teeth (n=104) with occlusal surfaces varying from sound to cavitated were selected. Sites were identified from 10x occlusal surface photographs. Standardized bitewing (BW) radiographs were taken. Four dentists with at least five years of experience scored all teeth twice (one-week interval) for ICDAS (0-6), BW (0=sound, 1=caries restricted to enamel, 2=caries in outer third dentin, 3=caries in inner third dentin), and TD (0=no treatment, 1=sealant, 2=microabrasion and sealant, 3=round bur sealant, 4a=resin, 4b=amalgam). Histological validation was performed by observation under a light microscope, with lesions classified on a five-point scale. Intraexaminer and inter-examiner repeatability were assessed using two-way tables and intraclass correlation coefficients (ICCs). Comparisons between percentage correct, specificity, sensitivity, and area under the receiver-operating characteristic (ROC) curve were performed using bootstrap analyses. ICCs for intraexaminer and interexaminer repeatability indicated good repeatability for each examiner, ranging from 0.78 to 0.88, and among examiners, ranging from 0.74 to 0.81. Correlation between ICDAS and TD was 0.85 and between BW and TD was 0.78. Correlation between the methods and histological scores was moderate (0.63 for ICDAS and 0.61 for BW). The area under the ROC curve was significantly greater for ICDAS than for BW (p<0.0001). ICDAS had significantly lower specificity than BW did (p=0.0269, 79% vs 94%); however, sensitivity was much higher for ICDAS than for BW (p<0.0001, 83% vs 44%). Data from this investigation suggested that the visual examination (ICDAS) showed better performance than radiographic examination for occlusal caries detection. The ICDAS was strongly associated with TD. Although the correlation between the ICDAS and BW was lower, it is still valuable in the clinical decision-making process.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Sera of patients with paracoccidioidomycosis contained IgG-, IgA-, and IgM-specific antibodies to a 43 kDa antigen contained in the filtrate of a culture of Paracoccidioides brasiliensis. IgG- and IgA-specific antibodies were present in all observed patients. The IgM response was more frequent in acute cases, and the mean titers of IgG- and IgM-specific antibodies were higher in the acute forms. By the fourth month of chemotherapy, there was a decay of IgG, IgA, and IgM antibody titers to this antigen in acute cases, correlating with clinical improvement. The detection of IgG and IgA antibodies and the sequential determination of antibodies to the 43 kDa glycoprotein may be useful tools for serodiagnosis and evaluation of therapeutic efficacy.
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The extract prepared from dried seeds of Cucurbita maxima was administered to rats and pigs. Following a single dose or 4 weeks of daily oral administration, the extract produced no changes in serum glucose, urea, creatinine, total protein, uric acid, GOT, GPT, LDH or blood counts. Urine analysis (urea, uric acid, creatinine, total protein, Na and K), as well as histopathological investigation, showed no abnormalities. These results taken as a whole indicate that the seeds of C. maxima as used in Brazilian folk medicine are not toxic for rats and swine.
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A study was carried out to assess the stability of antimicrobial susceptibility of wild isolates upon long-term storage using fifty-three Escherichia coli strains isolated in 1978 from feces of healthy children from the Amazon region in Brazil, exposed to low levels of antimicrobial agents, and examined for resistance to mercury and four antibiotics. All of the strains were kept in Lignieres medium at room temperature and were transferred to fresh media four times during this period. Thirty-five out of the 53 strains analyzed in 1978 were viable. Upon recovery, antibiotic and mercury resistance was estimated. All of the 35 strains maintained their original phenotype in a stable fashion, except for one multiresistant strain which became susceptible to kanamycin. Fifty-four percent of the strains exhibited a resistance phenotype, among which 47% had conjugative plasmids.
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This study evaluated the microleakage of pit and fissure sealants after different surface preparation (invasive technique and laser irradiation) and the use of different materials (fluoride resin-filled sealant, resin-modified glass ionomer cement and adhesive system). Eighty-four pre molars were used in this study, which were divided into seven groups. After the accomplishment of the different treatments, these were submitted to thermocycling process and assess for microleakage by examination under an epifluorescent microscope and scored zero to seven. Two specimens of each group were observed under scanning electron microscope (SEM). The results showed that laser irradiation did not lessen microleakage in pit and fissures when using a filled-resin sealant with fluoride or a resin-modified glass ionomer cement. The use of laser irradiation and adhesive system, followed by a resin-filled sealant with fluoride, showed the lowest microleakage scores in pit and fissures. Comparing this group to the resin-modified glass ionomer cement group, there was statistical significance. The use of a adhesive system decreased microleakage when using a fluoride resin-filled sealant with or without previous laser irradiation; although it was not statistically significant.
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An ambiguity in the computation of the one-loop effective action for fields living on a cone is illustrated. It is shown that the ambiguity arises due to the noncommutativity of the regularization of ultraviolet and (conical) boundary divergencies. ©1999 The American Physical Society.