2,416 research outputs found

    MEASURING QUALITY OBJECTIVELY AND NONDESTRUCTIVELY

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    Discusses the various tests currently used to measure quality of fruits and vegetables.Agribusiness,

    Formulation of linguistic regression model based on natural words

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    When human experts express their ideas and thoughts, human words are basically employed in these expressions. That is, the experts with much professional experiences are capable of making assessment using their intuition and experiences. The measurements and interpretation of characteristics are taken with uncertainty, because most measured characteristics, analytical result, and field data can be interpreted only intuitively by experts. In such cases, judgments may be expressed using linguistic terms by experts. The difficulty in the direct measurement of certain characteristics makes the estimation of these characteristics imprecise. Such measurements may be dealt with the use of fuzzy set theory. As Professor L. A. Zadeh has placed the stress on the importance of the computation with words, fuzzy sets can take a central role in handling words [12, 13]. In this perspective fuzzy logic approach is offten thought as the main and only useful tool to deal with human words. In this paper we intend to present another approach to handle human words instead of fuzzy reasoning. That is, fuzzy regression analysis enables us treat the computation with words. In order to process linguistic variables, we define the vocabulary translation and vocabulary matching which convert linguistic expressions into membership functions on the interval [0–1] on the basis of a linguistic dictionary, and vice versa. We employ fuzzy regression analysis in order to deal with the assessment process of experts from linguistic variables of features and characteristics of an objective into the linguistic expression of the total assessment. The presented process consists of four portions: (1) vocabulary translation, (2) estimation, (3) vocabulary matching and (4) dictionary. We employed fuzzy quantification theory type 2 for estimating the total assessment in terms of linguistic structural attributes which are obtained from an expert

    An analysis of nearfield normal mode amplitude anomalies of the Landers Earthquake

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    The 1992 Landers earthquake (M_w=7.3) occurred in the middle of the TERRAscope network. Long-period Rayleigh waves recorded at the TERRAscope stations (Δ≤3°) after traveling around the Earth show large amplitude anomalies, one order of magnitude larger than spherical Earth predictions up to a period of about 600 s. The ground motions over the epicentral region at and after the arrival of R4–5 are in phase at all stations. These observations are inconsistent with the nearly vertical strike slip mechanism of the Landers earthquake. Synthetic seismograms for a rotating, elliptic and laterally heterogeneous Earth model calculated by the variational method agree well with the observed waveforms. Calculations for various 3D Earth models demonstrate that the amplitudes are very sensitive to the large scale aspherical structure in the crust and the mantle. The anomalies for modes shorter than 300 s period can be explained by lateral heterogeneity shallower than the upper mantle. Rotation of the Earth and lower mantle heterogeneity are required to explain mode amplitudes at longer periods. Current whole mantle seismic tomographic models can fully explain the observed amplitudes longer than 300 s. To assess the effect of the high order lateral heterogeneity in the mantle more precise estimate of the crustal correction is required

    An enhanced possibilistic programming model with fuzzy random confidence-interval for multi-objective problem

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    Mathematical models are established to represent real-world problems. Since the real-world faces various types of uncertainties, it makes mathematical model suffers with insufficient uncertainties modeling. The existing models lack of explanation in dealing uncertainties. In this paper, construction of mathematical model for decision making scenario with uncertainties is presented. Primarily, fuzzy random regression is applied to formulate a corresponding mathematical model from real application of a multi-objective problem. Then, a technique in possibilistic theory, known as modality optimization is used to solve the developed model. Consequently, the result shows that a well-defined multi-objective mathematical model is possible to be formulated for decision making problems with the uncertainty. Indeed, such problems with uncertainties can be solved efficiently with the presence of modality optimization

    Changes in carotid intima-media thickening in patients with type 2 diabetes mellitus: Subanalysis of the Sitagliptin Preventive Study of Intima-Media Thickness Evaluation

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    Type 2 diabetes mellitus is a risk factor for cardiovascular disease. Both the absolute value and progression of carotid artery intima‐media thickness (IMT) are considered a marker of progression of atherosclerosis. We reported recently that treatment with sitagliptin, a dipeptidyl peptidase‐4 inhibitor, attenuated the progression of carotid IMT in insulin‐treated patients with type 2 diabetes mellitus compared with conventional therapy1. Here, we compared the efficacy of treatment with sitagliptin with that of other modalities on the progression of carotid IMT in prespecified subgroups of the Sitagliptin Preventive Study of Intima‐Media Thickness Evaluation (SPIKE) registered on the University Hospital Medical Information Network Clinical Trials Registry (UMIN000007396)1, 2. The aim of the comparison was to identify the characteristics of patients who benefited most from the sitagliptin treatment in terms of decrease in IMT.The recruits in the original study included 282 insulin‐treated Japanese type 2 diabetes mellitus patients free of past history of apparent cardiovascular disease. They were randomly allocated to either the sitagliptin group (n = 142) or the conventional treatment group (using drugs other than sitagliptin; n = 140). After the exclusion of eight patients, data of 137 patients of the sitagliptin group and 137 of the conventional treatment group were subjected to analysis. The mean‐IMT of the common carotid arteries (mean‐IMT‐CCA) and right and left max‐IMT‐CCA were measured by expert sonographers at the start of the study, and the procedure was repeated after 52 and 104 weeks, as reported previously1, 2. Figure 1 shows differences in treatment‐induced delta change in carotid IMT, relative to baseline in 243 patients whose IMT data were available at baseline and 104 weeks, according to various predefined risk factors for atherosclerosis. The results showed consistent reductions in mean IMT‐CCA and left max IMT‐CCA, but not right max IMT‐CCA, in the sitagliptin group (Figure 1). In particular, a greater reduction in carotid IMT was noted after treatment with sitagliptin in patients with risk factors for cardiovascular disease, such as higher glycated hemoglobin, higher body mass index, longer duration of type 2 diabetes mellitus, use of angiotensin‐converting enzyme inhibitors/angiotensin II receptor blocker, use of statins, worse hypertension and/or hyperlipidemia at baseline, compared with conventional treatment. These data suggest that treatment with dipeptidyl peptidase‐4 inhibitors seems to prevent the progression of carotid atherosclerosis regardless of disease burden. Previous studies showed that treatment with statins and angiotensin‐converting enzyme inhibitors reduces the progression of carotid atherosclerosis in patients with type 2 diabetes mellitus3, 4. In this subgroup analysis, sitagliptin still attenuated the progression of carotid IMT, even in patients who were receiving those therapies. Thus, dipeptidyl peptidase‐4 inhibitors seem to have unique and/or additive anti‐atherosclerotic effects as add‐on therapy to statins and/or angiotensin‐converting enzyme inhibitors/angiotensin II receptor blockers

    Dose-Dependent Effect of Sitagliptin on Carotid Atherosclerosis in Patients with Type 2 Diabetes Mellitus Receiving Insulin Treatment: A Post Hoc Analysis

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    IntroductionDipeptidyl peptidase-4 (DPP-4) inhibitors reduce blood glucose in a dose-dependent manner, but the dose-dependent effect relationship between DPP-4 inhibitors and atherosclerosis has not been investigated.MethodsPatients with type 2 diabetes mellitus (T2DM) treated with insulin were randomized to the sitagliptin (n = 137) or conventional treatment group (n = 137). In the sitagliptin group, each investigator was allowed to adjust the sitagliptin dose to avoid hypoglycemia. In this post hoc analysis, subjects in the sitagliptin group were divided into two groups based on the average dose of sitagliptin during the study period: greater than or equal to median (higher sitagliptin dose group) or less than median (lower sitagliptin dose group).ResultsIn this study, subjects were divided into three groups: the conventional treatment group (n = 137), lower sitagliptin dose group (n = 42), and higher sitagliptin dose group (n = 95). The higher sitagliptin dose group had a significantly larger reduction in HbA1c (−0.62 ± 1.05%) than the conventional treatment group (−0.20 ± 0.91%, P = 0.007). Over 104 weeks, the higher sitagliptin dose significantly reduced the mean intima media thickness-common carotid artery (IMT-CCA) and left max-IMT-CCA relative to baseline. In addition, the higher sitagliptin dose significantly inhibited the progression in mean-IMT-CCA compared with conventional treatment. Multiple linear regression analysis showed that changes in mean-IMT-CCA and left max-IMT-CCA decreased with higher sitagliptin dose.ConclusionsAddition of sitagliptin to insulin therapy might attenuate the progression of atherosclerosis in patients with T2DM in a dose-dependent manner

    The Effect of Sitagliptin on the Regression of Carotid Intima-Media Thickening in Patients with Type 2 Diabetes Mellitus: A Post Hoc Analysis of the Sitagliptin Preventive Study of Intima-Media Thickness Evaluation

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    Background. The effect of dipeptidyl peptidase-4 (DPP-4) inhibitors on the regression of carotid IMT remains largely unknown. The present study aimed to clarify whether sitagliptin, DPP-4 inhibitor, could regress carotid intima-media thickness (IMT) in insulin-treated patients with type 2 diabetes mellitus (T2DM). Methods. This is an exploratory analysis of a randomized trial in which we investigated the effect of sitagliptin on the progression of carotid IMT in insulin-treated patients with T2DM. Here, we compared the efficacy of sitagliptin treatment on the number of patients who showed regression of carotid IMT of ≥0.10 mm in a post hoc analysis. Results. The percentages of the number of the patients who showed regression of mean-IMT-CCA (28.9% in the sitagliptin group versus 16.4% in the conventional group, P = 0.022) and left max-IMT-CCA (43.0% in the sitagliptin group versus 26.2% in the conventional group, P = 0.007), but not right max-IMT-CCA, were higher in the sitagliptin treatment group compared with those in the non-DPP-4 inhibitor treatment group. In multiple logistic regression analysis, sitagliptin treatment significantly achieved higher target attainment of mean-IMT-CCA ≥0.10 mm and right and left max-IMT-CCA ≥0.10 mm compared to conventional treatment. Conclusions. Our data suggested that DPP-4 inhibitors were associated with the regression of carotid atherosclerosis in insulin-treated T2DM patients. This study has been registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000007396)
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