166 research outputs found
Unveiling and unraveling aggregation and dispersion fallacies in group MCDM
Priorities in multi-criteria decision-making (MCDM) convey the relevance
preference of one criterion over another, which is usually reflected by
imposing the non-negativity and unit-sum constraints. The processing of such
priorities is different than other unconstrained data, but this point is often
neglected by researchers, which results in fallacious statistical analysis.
This article studies three prevalent fallacies in group MCDM along with
solutions based on compositional data analysis to avoid misusing statistical
operations. First, we use a compositional approach to aggregate the priorities
of a group of DMs and show that the outcome of the compositional analysis is
identical to the normalized geometric mean, meaning that the arithmetic mean
should be avoided. Furthermore, a new aggregation method is developed, which is
a robust surrogate for the geometric mean. We also discuss the errors in
computing measures of dispersion, including standard deviation and distance
functions. Discussing the fallacies in computing the standard deviation, we
provide a probabilistic criteria ranking by developing proper Bayesian tests,
where we calculate the extent to which a criterion is more important than
another. Finally, we explain the errors in computing the distance between
priorities, and a clustering algorithm is specially tailored based on proper
distance metrics
Quasi-static and impact cutting behavior definition of privet stem
Some of agricultural operations such as privet stem pruning are slowly, repetitive and occasionally dangerous for operators. Almost operators of privet trimmers are exposed to the unpleasant and dangerous arm and body vibrations and sound of pruning machines. The knowing of the shearing behaviors of privet stem have important role in the design and fabricate of suitable pruning machine. So a series of experimental tests were performed to measuring the shear force, shear consumption energy and shear strength of stem internodes of privet stalk under quasi-static and impact cutting at different loading rate, different internode position and moisture level 58% wet base. In the quasi-static cutting test, the stalk specimens were cut in the quasi-static process at four loading rates: 5, 10, 15 and 20 mm/min and three internode positions: fifth, tenth and fifteenth. In impact cutting test, the stalk specimens were served in impact process at four loading rates: 1, 2, 3 and 4 m/s and three internode positions: fifth, tenth and fifteenth. In quasi-static cutting, the variance analysis of the data indicated that the loading rate, created significant effect on shear strength and shear consumption energy in probability level of 5%. Also the internode position and the interaction effect of loading rate and internode position, created significant effects on shear strength and shear consumption energy in probability level of 1%. Based on the statistical analysis, the average values of shear consumption energy and shear strength were obtained as 556.70 J from 95.35 to 1567.95 J and 29.12 Mpa from 19.63 to 37.04 Mpa respectively. In impact cutting, the variance analysis of the data results showed that the effect of loading rate, the effect of internode position and interaction effect of loading rate on internode position, created significant effect on shear consumption energy and shear strength in probability level of 1%. The data statistical analysis showed the average values of shear consumption energy and shear strength were obtained as 17.16 J from 3.19 to 28.60 J and 1.01 Mpa from 0.21 to 2.53 Mpa respectively
Association between Socioeconomic Factors and the Risk of Gastric Cancer Incidence:Results from an Ecological Study
Association between Socioeconomic Factors and the Risk of Gastric Cancer Incidence:Results from an Ecological Study
Background: Gastric cancer (GC), one of the most common cancer worldwide, remains the third leading cause of cancer-related mortality. The etiology of GC may arise from genetic and environmental factors. This study aimed to determine the association between GC incidence and socioeconomic status in Iran. Methods: An ecological study was designed to investigate the relationship between socioeconomic factors and the risk of GC incidence. The data of socioeconomic variables such as income changes, unemployment rate, urbanization ratio, inflation rate, and air pollution changes in 31 provinces were collected from the Statistical Center of Iran, and the data of GC of 31 provinces were provided from the Iranian National Population-based Cancer Registry (INPCR). Data from 2014 to 2017 was analyzed using panel data analysis, the fixed effects model by EViews software. Results: Panel data model was suitable for the present study. Results showed that there was a positive and significant relationship between GC incidence and socioeconomic factors including income changes (P≤ 0.001), unemployment rate (P≤0.01), inflation rate (P≤ 0.05), and air pollution changes (P≤ 0.001). The urbanization ratio showed a negative relationship and was not statistically associated with GC incidence (P> 0.05). Conclusion: Our findings suggest a positive and significant association between socioeconomic status and GC incidence, proposing a GC risk factor. The key public health policies and welfare policies' priority should there-fore be to schedule for the GC management.</p
A Novel Intelligent Control System Design for Water BathTemperature Control
Abstract: In this paper a neuro-fuzzy controller (NFC) for temperaturecontrol of a water bath system is proposed.A five layer neural network is used to adjust input and output parameters of membership function in a fuzzy logic controller. The hybrid learning algorithm is used for training this network. The simulation results show that the proposedcontroller has good set point tracking and disturbance rejectionproperties. Also it is robust against changes in the systemparameters. It is also superior to the conventional PID controller
Effect of Ramadan fasting on blood glucose levels and continues performance test (CPT)
Background and aim: One of the religious duties during the holly month of Ramadan is fasting. During the fasting time, blood glucose level is decreased. Hypoglycemia decreases the individual cognition function. The standard continues performance test (CPT) determines cognitive performance of individuals. The aim of this study was to determine the effectiveness of fasting blood glucose level on cognitive performance in the clergymen and clergywomen (religious leaders) during the holly Ramadan month in religious institutes. Methods: In this study, 110 volunteers were selected from clergymen and clergywomen who were in fasting in Ramadan month. From the whole participants 68 persons were clergymen and 42 persons were clergywomen. The selected participants were tested for blood glucose test and CPT test in four stages (Two weeks before Ramadan, second week of Ramadan, fourth week of Ramadan and finally one month after Ramadan). Data were analyzed by analytic and descriptive statistics and SPSS software. Results: Paired t-test revealed that the blood glucose levels in the fourth week of the Ramadan month was significantly less than the ones in the second week of Ramadan. Spearmans rank correlation coefficient test confirmed a significant relation the between results of blood glucose test and CPT test (P<0.05). No significant relationship was obtained between CPT and age or gender. Conclusion: Results revealed that inconsistent and short time starvation in Ramadan month does not impair cognitive performance. Cognitive performance markers have been reported normal in all processes, if treats of food serves are determined about eight through twelve hours
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Topical gel of Metformin solid lipid nanoparticles: a hopeful promise as a dermal delivery system
The aim of the present study was to enhance the skin delivery of metformin by making solid lipid nanoparticles containing metformin using the ultra-sonication method. To achieve the optimum skin delivery for metformin, the effects of the ratio of two surfactants (Tween:Span) on nanoparticles properties and their performance were investigated. Photon correlation spectroscopy, scanning electron microscopy (SEM), Powder X-ray Diffractometer (PXRD), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to characterize the solid state of metformin in solid lipid nanoparticles. Generally, the particle size of nanoparticles decreased by the addition of co-emulsifier (Span®60). Results showed that all formulations made by binary mixtures of surfactants had low particle size, low Polydispersity index and high zeta potential. It was interesting to note that the smallest nanoparticles (203.8 ± 15.356) was obtained when the HLB of the binary surfactants (HLB of 11.67) was closer to the HLB of beeswax (HLB of 12) used in the preparation of SLN. It was also found that by decreasing the HLB of the system from 14.9 to 10.06 the zeta potential of SLNs increased from −0.651 ± 0.315 to −6.18 ± 0.438 mV. But, a further reduction in the HLB from 10.06 to 8.45 caused a reduction in the zeta potential from −6.18 to −3.596 ± 0.255. Results showed that the highest entrapment efficiency of 45.98 ± 9.20% was obtained for formulation with larger particle size and with the highest HLB value (HLB 14.9). DSC study showed that metformin in SLN is in an amorphous form. FT-IR spectra of Met-SLN showed that the prominent functional groups existed in the formulations which could be an indication of good entrapment of metformin in a lipid matrix. FT-IR results also ruled out any chemical interaction between the drug and the excipients. The amounts of metformin detected in the skin layers and the receptor chamber at all sampling times were higher for nanogel compared to metformin gel. This is an indication of a better performance of Metformin nanogel ex-vivo and could be developed further for clinical studies
Optimized Implementation of Memristor-Based Full Adder by Material Implication Logic
Recently memristor-based applications and circuits are receiving an increased
attention. Furthermore, memristors are also applied in logic circuit design.
Material implication logic is one of the main areas with memristors. In this
paper an optimized memristor-based full adder design by material implication
logic is presented. This design needs 27 memristors and less area in comparison
with typical CMOS-based 8-bit full adders. Also the presented full adder needs
only 184 computational steps which enhance former full adder design speed by 20
percent.Comment: International Conference on Electronics Circuits and Systems (ICECS),
201
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