Duality in Fuzzy Linear Programming with Symmetric Trapezoidal Numbers

Linear programming problems with trapezoidal fuzzy numbers have recently attracted much interest. Various methods have been developed for solving these types of problems. Here, following the work of Ganesan and Veeramani and using the recent approach of Mahdavi-Amiri and Nasseri, we introduce the dual of the linear programming problem with symmetric trapezoidal fuzzy numbers and establish some duality results. The results will be useful for post optimality analysis

Novel inerter-based absorbers for suppressing beams vibration under successive moving loads

Inerter-based vibration absorbers are new generations of tuned mass dampers. The property of the inerter is that the relative acceleration between its two terminals is proportional to produced force. This paper proposes the use of inerter-based vibration absorbers for suppressing the beam vibration under successive moving loads. The vibrational system possesses continuous beam model accompanying by inerter-based vibration absorbers. The effectiveness of this new type of vibration absorber compared with the ordinary linear vibration absorber. The partial differential governing equation converts to a system of ordinary differential equations using the Bubnov–Galerkin method. The optimal parameters of the inerter-based vibration absorbers are presented. The results show that this novel vibration absorber can reduce vibration 37% more than the optimized classical linear vibration absorbers. Some results give quasi-beating response for the beam possesses inerter-based vibration absorbers

Measurement of spin-dependent conductivities in a two-dimensional electron gas

Spin accumulation is generated by injecting an unpolarized charge current into a channel of GaAs two-dimensional electron gas subject to an in-plane magnetic field, then measured in a non-local geometry. Unlike previous measurements that have used spin-polarized nanostructures, here the spin accumulation arises simply from the difference in bulk conductivities for spin-up and spin-down carriers. Comparison to a diffusive model that includes spin subband splitting in magnetic field suggests a significantly enhanced electron spin susceptibility in the 2D electron gas

Evaluating high risks in large-scale projects using an extended VIKOR method under a fuzzy environment

The complexity of large-scale projects has led to numerous risks in their life cycle. This paper presents a new risk evaluation approach in order to rank the high risks in large-scale projects and improve the performance of these projects. It is based on the fuzzy set theory that is an effective tool to handle uncertainty. It is also based on an extended VIKOR method that is one of the well-known multiple criteria decision-making (MCDM) methods. The proposed decision-making approach integrates knowledge and experience acquired from professional experts, since they perform the risk identification and also the subjective judgments of the performance rating for high risks in terms of conflicting criteria, including probability, impact, quickness of reaction toward risk, event measure quantity and event capability criteria. The most notable difference of the proposed VIKOR method with its traditional version is just the use of fuzzy decision-matrix data to calculate the ranking index without the need to ask the experts. Finally, the proposed approach is illustrated with a real-case study in an Iranian power plant project, and the associated results are compared with two well-known decision-making methods under a fuzzy environment

Correlation and factor analysis of grain yield and some important component characters in spring bread wheat genotypes

In order to evaluate several agro-morphological traits in 21 spring bread wheat genotypes, an experiment based on randomized complete block design with three replications was carried out in two locations during three years (2008- 2011).The traits including grain yield(GY), biological yield (BY), spike weight (SW), grain weight per spike(GWS), harvest index (HI), spike length (SL), spikelet per spike (SPS), number of grain per spike (NGS), number of spike per square meter (SPM), 1000-grain weight (GW), plant height (PH), stem straw weight (SSW), spike straw weight (SRW) were evaluated. The result of combined analysis of variance revealed that years, genotypes and their interaction effects were significant for all the traits. Location had significant difference for all the traits except SL and SPS. GY was significant correlated with BY (0.72**), SW (0.75**), GWS (0.69**), NGS (0.59**), SSW (0.62**) and SRW (0.66**). Factor analysis was used for understanding the data structure and trait relations. The factor analysis divided the thirteen traits into three factors. The cumulative variation for these factors was 0.76 and also it’s portions for factor one to three were 0.59, 0.16 and 0.06, respectively. In the first factor, the traits including GY, BY, SW, GWS, SPS, NGS and SSW had high factor loadings. The traits compromise HI, SSW and SRW had high factor loadings in second factor and also SPM, GW and PH had high values of factor loadings in third factor. The genotypes including Morvarid, N-80-19 and N-85-14 had high mean values of grain yield. The genotypes had high genetic coefficient variation for SRW, BY, SW and GY, therefore the efficiency of selection of the genotypes for improving these traits will be high

Holstein polaron in the presence of disorder

Non-local, inhomogeneous and retarded response observed in experiments is reproduced by introducing the Inhomogeneous Momentum Average (IMA) method to study single polaron problems with disorder in the on-site potential and/or spatial variations of the electron-phonon couplings and/or phonon frequencies. We show that the electron-phonon coupling gives rise to an additional inhomogeneous, strongly retarded potential, which makes instant approximations questionable. The accuracy of IMA is demonstrated by comparison with results from the approximation free Diagrammatic Monte Carlo (DMC) method. Its simplicity allows for easy study of many problems that were previously unaccessible. As an example, we show how inhomogeneities in the electron-phonon coupling lead to nonlocal, retarded response in scanning tunneling microscopy (STM) images.Comment: 4 pages, 3 figure

Fuzzy Efficiency Measures in Data Envelopment Analysis Using Lexicographic Multiobjective Approach

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.There is an extensive literature in data envelopment analysis (DEA) aimed at evaluating the relative efficiency of a set of decision-making units (DMUs). Conventional DEA models use definite and precise data while real-life problems often consist of some ambiguous and vague information, such as linguistic terms. Fuzzy sets theory can be effectively used to handle data ambiguity and vagueness in DEA problems. This paper proposes a novel fully fuzzified DEA (FFDEA) approach where, in addition to input and output data, all the variables are considered fuzzy, including the resulting efficiency scores. A lexicographic multi-objective linear programming (MOLP) approach is suggested to solve the fuzzy models proposed in this study. The contribution of this paper is fivefold: (1) both fuzzy Constant and Variable Returns to Scale models are considered to measure fuzzy efficiencies; (2) a classification scheme for DMUs, based on their fuzzy efficiencies, is defined with three categories; (3) fuzzy input and output targets are computed for improving the inefficient DMUs; (4) a super-efficiency FFDEA model is also formulated to rank the fuzzy efficient DMUs; and (5) the proposed approach is illustrated, and compared with existing methods, using a dataset from the literature

Evaluation of culturally-familiar odorants for a Persian smell identification test

Introduction: Processing odor information by the olfactory system depends greatly on the odor concentration. In order to use an odorant in a smell identification test (SIT), the minimum identification concentration (MIC) needs to be determined. Materials and Methods: This study was conducted in 60 healthy native individuals aged 20 to 60 years, selected from patients' companions in a tertiary hospital. In the first step, 25 odorants were presented to evaluate familiarity among the subjects. Then, the MICs for the eligible odorants were measured using the ascending method of limits. Results: Out of 25 odorants, only one (cacao) was distinguished by less than 70 of the subjects, and was therefore removed from the list. The MICs of the remaining 24 odorants ranged from 6.87±2.74 for menthol to 27.62±18.98 for cantaloupe. There was significant correlation between age and the MIC only for coffee (P=0.02, r=-0.300). There was a significant difference in MIC between men and women only for hazelnut (P=0.03). Conclusion: We present the MICs of 24 culturally-familiar odorants in a sample of the Persian population in a SIT

Evaluation of culturally-familiar odorants for a Persian smell identification test

Introduction: Processing odor information by the olfactory system depends greatly on the odor concentration. In order to use an odorant in a smell identification test (SIT), the minimum identification concentration (MIC) needs to be determined. Materials and Methods: This study was conducted in 60 healthy native individuals aged 20 to 60 years, selected from patients' companions in a tertiary hospital. In the first step, 25 odorants were presented to evaluate familiarity among the subjects. Then, the MICs for the eligible odorants were measured using the ascending method of limits. Results: Out of 25 odorants, only one (cacao) was distinguished by less than 70 of the subjects, and was therefore removed from the list. The MICs of the remaining 24 odorants ranged from 6.87±2.74 for menthol to 27.62±18.98 for cantaloupe. There was significant correlation between age and the MIC only for coffee (P=0.02, r=-0.300). There was a significant difference in MIC between men and women only for hazelnut (P=0.03). Conclusion: We present the MICs of 24 culturally-familiar odorants in a sample of the Persian population in a SIT