Phase structure of the generalized two dimensional Yang-Mills theories on sphere

We find a general expression for the free energy of $G(\phi)=\phi^{2k}$ generalized 2D Yang-Mills theories in the strong ($A>A_c$) region at large $N$. We also show that in this region, the density function of Young tableau of these models is a three-cut problem. In the specific $\phi^6$ model, we show that the theory has a third order phase transition, like $\phi^2$ (YM_2) and $\phi^4$ models. We have some comments for $k \geq 4$ cases. At the end, we study the phase structure of $\phi^2 + g \phi^4$ model for $g \leq A/4$ region.Comment: 13 pages, LaTex,the introduction section was changed,will be appeared in: Eur. Phys. J. C (1999

Denosing Using Wavelets and Projections onto the L1-Ball

Both wavelet denoising and denosing methods using the concept of sparsity are based on soft-thresholding. In sparsity based denoising methods, it is assumed that the original signal is sparse in some transform domains such as the wavelet domain and the wavelet subsignals of the noisy signal are projected onto L1-balls to reduce noise. In this lecture note, it is shown that the size of the L1-ball or equivalently the soft threshold value can be determined using linear algebra. The key step is an orthogonal projection onto the epigraph set of the L1-norm cost function.Comment: Submitted to Signal Processing Magazin

Phase and TV Based Convex Sets for Blind Deconvolution of Microscopic Images

In this article, two closed and convex sets for blind deconvolution problem are proposed. Most blurring functions in microscopy are symmetric with respect to the origin. Therefore, they do not modify the phase of the Fourier transform (FT) of the original image. As a result blurred image and the original image have the same FT phase. Therefore, the set of images with a prescribed FT phase can be used as a constraint set in blind deconvolution problems. Another convex set that can be used during the image reconstruction process is the epigraph set of Total Variation (TV) function. This set does not need a prescribed upper bound on the total variation of the image. The upper bound is automatically adjusted according to the current image of the restoration process. Both of these two closed and convex sets can be used as a part of any blind deconvolution algorithm. Simulation examples are presented.Comment: Submitted to IEEE Selected Topics in Signal Processin

Phase transition in multi-scalar-singlet extensions of the Standard Model

We propose a generalization of the Standard Model (SM) by adding two real gaugesinglets S1, S2. The field S1 will improve the strength of the electroweak phase transition (EWPT). Imposing a Z2 symmetry on the field S2 makes this field a possible candidate for dark matter. Both singlets interact with other observable fields through Higgs boson. They are allowed to interact with each other as well. We find that by introducing two different scalar fields, the model is less vulnerable to experimental constraints. In this paper, we consider the effects of a heavy scalar(M1 > MH) on the electroweak phase transition. And we present configurations that produce a strong first order EWPT

Projections Onto Convex Sets (POCS) Based Optimization by Lifting

Two new optimization techniques based on projections onto convex space (POCS) framework for solving convex and some non-convex optimization problems are presented. The dimension of the minimization problem is lifted by one and sets corresponding to the cost function are defined. If the cost function is a convex function in R^N the corresponding set is a convex set in R^(N+1). The iterative optimization approach starts with an arbitrary initial estimate in R^(N+1) and an orthogonal projection is performed onto one of the sets in a sequential manner at each step of the optimization problem. The method provides globally optimal solutions in total-variation, filtered variation, l1, and entropic cost functions. It is also experimentally observed that cost functions based on lp, p<1 can be handled by using the supporting hyperplane concept

An integrated neural network algorithm for optimum performance assessment of auto industry with multiple outputs and corrupted data and noise

In the real world encountering with noisy and corrupted data is unavoidable. Auto industry sector (AIS) as a one of the significant industry encounters with noisy and corrupted data regarding to its rapid development. Therefore, developing the performance assessment in this situation is so helpful for this industry. As Data envelopment Analysis (DEA) could not deal with noisy and corrupted data, the alternative method(s) is very important. As one of excellent and promising feature of artificial neural networks (ANNs) are theirs flexibility and robustness in noisy situation, they are a good alternative. This study proposes a non-parametric efficiency frontier analysis method based on the adaptive neural network technique for measuring efficiency as a complementary tool for the common techniques for efficiency assessment in the previous studies. The proposed computational method is able to find a stochastic frontier based on a set of input–output observational data and do not require explicit assumptions about the function structure of the stochastic frontier. In this algorithm, for calculating the efficiency scores of auto industry in various countries, a similar approach to econometric methods has been used. Moreover, the effect of the return to scale of AIS on its efficiency is included and the unit used for the correction is selected by notice of its scale (under constant return to scale assumption). Another feature of proposed algorithm is its ability to calculate efficiency for multiple outputs. An example using real data is presented for illustrative purposes. In the application to the auto industries, we find that the neural network provide more robust results and identifies more efficient units than the conventional methods since better performance patterns are explored. To test the robustness of the efficiency results of the proposed method, the ability of proposed ANN algorithm in dealing with noisy and corrupted data is compared with Data Envelopment Analysis (DEA). Results of the robustness check show that the proposed algorithm is much more robust to the noise and corruption in input data than DEA

CPOE in Iran-A viable prospect?. Physicians' opinions on using CPOE in an Iranian teaching hospital

Background: In recent years, the theory that on-line clinical decision support systems can improve patients' safety among hospitalised individuals has gained greater acceptance. However, the feasibility of implementing such a system in a middle or low-income country has rarely been studied. Understanding the current prescription process and a proper needs assessment of prescribers can act as the key to successful implementation. Objectives: The aim of this study was to explore physicians' opinions on the current prescription process, and the expected benefits and perceived obstacles to employ Computerised Physician Order Entry in an Iranian teaching hospital. Methods: Initially, the interview guideline was developed through focus group discussions with eight experts. Then semi-structured interviews were held with 19 prescribers. After verbatim transcription, inductive thematic analysis was performed on empirical data. Forty hours of on-looker observations were performed in different wards to explore the current prescription process. Results: The current prescription process was identified as a physician-centred, top-down, model, where prescribers were found to mostly rely on their memories as well as being overconfident. Some errors may occur during different paper-based registrations, transcriptions and transfers. Physician opinions on Computerised Physician Order Entry were categorised into expected benefits and perceived obstacles. Confidentiality issues, reduction of medication errors and educational benefits were identified as three themes in the expected benefits category. High cost, social and cultural barriers, data entry time and problems with technical support emerged as four themes in the perceived obstacles category. Conclusions: The current prescription process has a high possibility of medication errors. Although there are different barriers confronting the implementation and continuation of Computerised Physician Order Entry in Iranian hospitals, physicians have a willingness to use them if these systems provide significant benefits. A pilot study in a limited setting and a comprehensive analysis of health outcomes and economic indicators should be performed, to assess the merits of introducing Computerised Physician Order Entry with decision support capabilities in Iran. © 2008 Elsevier Ireland Ltd. All rights reserved

The Anatomical Position of Appendix in Iranian Cadavers

Background: Vermiform appendix is different in terms of anatomical position, length and mesoappendix.  Knowing the anatomical position of vermiform appendix is important for the surgeons in terms of diagnosis and management. The aim of this study is analysis of length, anatomical position and mesoappendix of vermiform appendix.Methods: This is a cross-sectional study on the 400 randomly selected cadavers (306 male and 94 female) who have been referred to the autopsy hall of legal medicine organization of Tehran province to be autopsied between March 21, 2010 and March, 2011. The cause of death was very heterogeneous among autopsied cadavers.Results:According to our results the anatomical positions were pelvic, subcecal, retroileal, retrocaecal, ectopic and preileal in 55.8%, 19%, 12.5%, 7%, 4.2% and 1.5% respectively. The mean length of vermiform appendix was 91.2 mm and 80.3 mm in men and women, respectively. Mesoappendix was complete in 79.5% and incomplete in 20.5%. No association was seen between sex and anatomical position of vermiform appendix.Conclusion:Anterior anatomical position was the most frequent vermiform appendix position in our population which is in discrepancy with most of the reports from western countries. It might be possible that factors such as race, geographical regions and nutritional regiment play roles in determining the position of vermiform appendix