A new super-efficiency model in the presence of negative data

This paper proposes a new super-efficiency model when some factors (inputs/outputs) are negative. The proposed model employs the RDM model (Portela et al, 2004) for ranking decision-making units (DMUs). Our model ranks the DMUs and determines the type of efficiency for each DMU, simultaneously     

Monocyclic phenolic acids; hydroxy- and polyhydroxybenzoic acids: occurrence and recent bioactivity studies

Among the wide diversity of naturally occurring phenolic acids, at least 30 hydroxy- and polyhydroxybenzoic acids have been reported in the last 10 years to have biological activities. The chemical structures, natural occurrence throughout the plant, algal, bacterial, fungal and animal kingdoms, and recently described bioactivities of these phenolic and polyphenolic acids are reviewed to illustrate their wide distribution, biological and ecological importance, and potential as new leads for the development of pharmaceutical and agricultural products to improve human health and nutrition.     

A Theoretical Study on Chapman Rearrangement

Some Chapman rearrangements are investigated using HF and B3LYP methods combined with two different basis sets (6‐31G** and 6‐31++G**) and both finite difference model and Janak's approximation. It is shown that although minimum polarizability (MPP) and maximum hardness (MHP) principles are always valid in these reactions, minimum electrophilicity principle (MEP) is followed just when DFT method (B3LYP) is used. The Morrel's rules are also successfully applied in predicting the validity of MEP in these rearrangements. Therefore, it seems that in the study of this kind of reaction, the results of DFT are more reliable than those of HF.     

On the latest starting times and criticality of activities in a network with imprecise durations

This paper deals with problems of computing possible values of latest starting times and determining types of criticality for all activities in a network with interval or fuzzy activity durations. Although the problem of computing the latest starting times has been solved, a novel polynomial algorithm which is easy to understand and improves complexity is proposed.     

"Mass defect" tags for biomolecular mass spectrometry

We present a new class of "mass defect" tags with utility in biomolecular mass spectrometry. These tags, incorporating element(s) with atomic numbers between 17 (Cl) and 77 (Ir), have a substantially different nuclear binding energy (mass defect) from the elements common to biomolecules. This mass defect yields a readily resolvable mass difference between tagged and untagged species in high-resolution mass spectrometers. We present the use of a subset of these tags in a new protein sequencing application. This sequencing technique has advantages over existing mass spectral protein identification methodologies: intact proteins are quickly sequenced and unambiguously identified using only an inexpensive, robust mass spectrometer. We discuss the potential broader utility of these tags for the sequencing of other biomolecules, differential display applications and combinatorial methods.     

A fast and stable first-order method for simulation of flexible beams and cables

Nonlinear Dynamics - Gradient deficient beam elements (commonly known as cable elements in the literature) based on the absolute nodal coordinate formulation (ANCF) have great potential for...     

Conditionally specified models and dimension reduction in the exponential families

We consider informative dimension reduction for regression problems with random predictors. Based on the conditional specification of the model, we develop a methodology for replacing the predictors with a smaller number of functions of the predictors. We apply the method to the case where the inverse conditional model is in the linear exponential family. For such an inverse model and the usual Normal forward regression model it is shown that, for any number of predictors, the sufficient summary has dimension two or less. In addition, we develop a test of dimensionality. The relationship of our method with the existing dimension reduction theory based on the marginal distribution of the predictors is discussed.     

Development of vibration signature analysis using multiwavelet systems

In this paper the vibration analysis for local faults and transient phenomena detection, using multiwavelet systems, is developed. Unlike the scalar wavelet systems, in which their coefficients are scalar parameters, the transformation coefficients of multiwavelet systems are vector valued, and their calculation requires specialized techniques. In this investigation, having considered the technique used to obtain the scalar wavelet system coefficients, the transformation coefficients of the multiwavelet system are calculated, and by applying the method to artificial vibration signals, decomposition of the signal into different multiscale and multiwavelet functions (as introduced by Donovan, Geronimo, Hardin and Massopust) is examined, as well as the capability of this multiwavelet system for transient phenomena detection. By analyzing the vibration signal of a faulty gearing system the applicability of Donovan, Geronimo, Hardin and Massopust multiwavelet system for local fault detection of the mechanical systems is shown. The results confirm that using the multiwavelet system, not only can the fault in the gearing system be diagnosed, but also its location can be determined precisely.     

Associated primes and cofiniteness of local cohomology modules

Let be an ideal of Noetherian ring R and let s be a non-negative integer. Let M be an R-module such that is finite R-module. If s is the first integer such that the local cohomology module is non -cofinite, then we show that is finite. In particular, the set of associated primes of is finite. Let be a local Noetherian ring and let M be a finite R-module. We study the last integer n such that the local cohomology module is not -cofinite and show that n just depends on the support of M.The research of the first author was supported in part by a grant from IPM (No. 83130114).The second author was supported by a grant from University of Tehran (No. 6103023/1/01).     

Independent fuzzy events

An algorithm for the reconstruction of a symmetric matrix from the spectral data is given. All cases in which the number of solutions is finite are determined. These results are applied to a certain inverse eigenvalue problem which arises in molecular spectroscopy.