NEW CLUSTERING SCHEMES FOR WIRELESS SENSOR NETWORKS

In this paper, two clustering algorithms are proposed. In the first one, we investigate a clustering protocol for single hop wireless sensor networks that employs a competitive scheme for cluster head selection. The proposed algorithm is named EECS-M that is a modified version to the well known protocol EECS where some of the nodes become volunteers to be cluster heads with an equal probability.  In the competition phase in contrast to EECS using a fixed competition range for any volunteer node, we assign a variable competition range to it that is related to its distance to base station. The volunteer nodes compete in their competition ranges and every one with more residual energy would become cluster head. In the second one, we develop a clustering protocol for single hop wireless sensor networks. In the proposed algorithm some of the nodes become volunteers to be cluster heads. We develop a time based competitive clustering algorithm that the advertising time is based on the volunteer node’s residual energy. We assign to every volunteer node a competition range that may be fixed or variable as a function of distance to BS. The volunteer nodes compete in their competition ranges and every one with more energy would become cluster head. In both proposed algorithms, our objective is to balance the energy consumption of the cluster heads all over the network. Simulation results show the more balanced energy consumption and longer lifetime

Predicting complexity perception of real world images

The aim of this work is to predict the complexity perception of real world images.We propose a new complexity measure where different image features, based on spatial, frequency and color properties are linearly combined. In order to find the optimal set of weighting coefficients we have applied a Particle Swarm Optimization. The optimal linear combination is the one that best fits the subjective data obtained in an experiment where observers evaluate the complexity of real world scenes on a web-based interface. To test the proposed complexity measure we have performed a second experiment on a different database of real world scenes, where the linear combination previously obtained is correlated with the new subjective data. Our complexity measure outperforms not only each single visual feature but also two visual clutter measures frequently used in the literature to predict image complexity. To analyze the usefulness of our proposal, we have also considered two different sets of stimuli composed of real texture images. Tuning the parameters of our measure for this kind of stimuli, we have obtained a linear combination that still outperforms the single measures. In conclusion our measure, properly tuned, can predict complexity perception of different kind of images

Comparison of the Therapeutic Efficacy of Azithromycin vs Tetracycline in Acne Vulgaris

ABSTRACT: Introduction & Objective: Acne vulgaris is a common skin disease which affects a large number of adolescents and adults at some time in their life. Several drugs have been used for the treatment of acne vulgaris and recently systemic azithromycin has been tried for its treatment. The aim of this study was to compare the therapeutic efficacy of azithromycin vs. tetracycline in acne vulgaris. Materials & Methods: The present study was a randomized investigator-blind clinical trial, carried out at the outpatient department of Besat Hospital of Sanandaj in 2008. 82 patients were allocated randomly into two groups. Azithromycin 500 mg for 3 consecutive days per week for the first month, then 250 mg/ every other day was prescribed for the first group .The second group received tetracycline 250 mg/6h .The treatments continued for 12 weeks. The therapeutic efficacy of these drugs was assessed on the basis of lesion counting. Data were introduced into SPSS 11.5 software and analyzed by means of independent t- test, Mann-Whitney and chi-square test. Results: The mean number of lesions was not statistically different before treatment in the two groups. There was statistically a significant difference in the mean number of inflammatory papular lesions on the face and back after treatment (p<0.05). However no significant difference was found in comedons lesions in both groups. The percentages of improvement of inflammatory papular lesions on the face and back were 82.3, 63.6 and 80.14 and 58.56 respectively (p<0.05). Conclusion: This study suggested that azithromycin was more effective than tetracycline in treating inflammatory papular lesions of acne vulgaris on the face and back. Azithromycin can be used as an alternative in the treatment of resistant inflammatory papular lesions to tetracycline. Keywords: Azithromycin, Acne Vulgaris, Tetracyclin

A Comparative Clinical Trial of Topical Triamcinolone (Adcortyle) and a Herbal Solution for the Treatment of Minor Aphthous Stomatitis

Introduction & Objective: Aphthous stomamtitis is characterized by single or multiple painful recurrent lesions in oral mucosa. Lesions can relapse in some patients for several years. Therefore treatment of such cases seems necessary. The aim of this study was to compare the therapeutic effect of topical Myrtus communis (myrtle) solution with topical triamcinolone (Adcortyle) in the treatment of minor apotheosis. Materials & Methods: This clinical-trial study was conducted at Kurdistan University of Medical Sciences in 2009. 100 patients were randomly assigned into 2 groups. The 1st group received topical myrtle solution. The 2nd group received topical trimcinolone (Adcortyle). After one week, patients' declaration about time of the recovery of the pain and deterioration of oral lesion was recorded. The gathered data was then analyzed using the SPSS statistical software using t-test and chi-square. Results: After treatment, both groups showed response to topical medications with no significant difference between them (p>0.05). Conclusion: results of this study showed that topical myrtle solution is effective in the treatment of minor aphthous stomatitis and its therapeutic effect is comparable with topical triamcinolone (Adcortyle)

Comparative efficacy of 2% Hydroquinone and Melfade in Treatment of Melasma

Introduction & Objective: Melasma is an acquired hypermelanosis disease and can cause superficial problems in women if left untreated. The objective of this study was to compare the efficacy of 2% hydroquinone and Melfade in the treatment of Melasma. Materials & Methods: This is a randomized clinical trial study conducted at Kurdistan University of Medical Sciences in 2008. Sixty two women with Melasma disease were recruited and randomly assigned to two groups. Two percent hydroquinone was prescribed for the first group (n=31) and Melfade for the second group. After 12 weeks of daily drug consumption by the patients, they were examined by a dermatologist for assessment of recovery. The collected data was analyzed by the SPSS software. Results: Response to treatment with hydroquinone and Melfade- was the same and no significant differences were found between the two groups. (P>0.05) onclusion: Results of this study demonstrated that topical Melfade is as effective as 2% hydrquinone in treatment of Melasma, Therefore it can be considered as an alternative drug in the treatment of Melasma