Multipath Separation-Direction of Arrival (MS-DOA) with Genetic Search Algorithm for HF channels

Cataloged from PDF version of article.Direction-of-Arrival (DOA) defines the estimation of arrival angles of an electromagnetic wave impinging on a set of sensors. For dispersive and time-varying HF channels, where the propagating wave also suffers from the multipath phenomena, estimation of DOA is a very challenging problem. Multipath Separation-Direction of Arrival (MS-DOA), that is developed to estimate both the arrival angles in elevation and azimuth and the incoming signals at the output of the reference antenna with very high accuracy, proves itself as a strong alternative in DOA estimation for HF channels. In MS-DOA, a linear system of equations is formed using the coefficients of the basis vector for the array output vector, the incoming signal vector and the array manifold. The angles of arrival in elevation and azimuth are obtained as the maximizers of the sum of the magnitude squares of the projection of the signal coefficients on the column space of the array manifold. In this study, alternative Genetic Search Algorithms (GA) for the maximizers of the projection sum are investigated using simulated and experimental ionospheric channel data. It is observed that GA combined with MS-DOA is a powerful alternative in online DOA estimation and can be further developed according to the channel characteristics of a specific HF link. (C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserve

Demographic and microbial characteristics of extrapulmonary tuberculosis cases diagnosed in Malatya, Turkey, 2001-2007

<p>Abstract</p> <p>Background</p> <p>Extrapulmonary tuberculosis (EPTB) has an increasing rate in Turkey. The reason remains largely unknown. A better understanding of the demographic and microbial characteristics of EPTB in the Turkish population would extend the knowledgebase of EPTB and allow us to develop better strategies to control tuberculosis (TB).</p> <p><b>Methods</b></p> <p>We retrospectively evaluated clinical and laboratory data of 397 bacteriologically-confirmed TB cases diagnosed during an eight year-period using by chi-square analysis and multivariate logistic regression model.</p> <p>Results</p> <p>Of the 397 study patients, 103 (25.9%) had EPTB and 294 (74.1%) had pulmonary tuberculosis (PTB). The most commonly seen two types of EPTB were genitourinary TB (27.2%) and meningeal TB (19.4%). TB in bone/joints, pleural cavity, lymph nodes, skin, and peritoneal cavity occurred at a frequency ranging from 9.7% to 10.7%. The age distribution was significantly different (P < 0.01) between PTB and EPTB, with patients older than 45 years tending to have an increased risk of EPTB. Furthermore, the distribution of different types of EPTB differed significantly among age groups (P = 0.03). Meningeal and bone and/or joint TB were more commonly observed among the male patients, while lymphatic, genitourinary, and peritoneal TB cases were more frequently seen among females. Unique strain infection was statistically significantly associated with EPTB (OR: 2.82, 95% CI [1.59, 5.00])</p> <p>Conclusions</p> <p>EPTB accounted for a significant proportion of TB cases in Malatya, Turkey between 2001 and 2007. The current study has provided an insight into the dynamics of EPTB in Malatya, Turkey. However, the risk factors for having EPTB in Malatya, Turkey remain to be assessed in future studies using population-based or randomly selected sample.</p

Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study

Introduction: Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs). Methods: We conducted a point prevalence study involving 128 PICUs in 26 countries across 6 continents. Over the course of 5 study days, 6925 PICU patients &lt;18 years of age were screened, and 706 with severe sepsis defined either by physician diagnosis or on the basis of 2005 International Pediatric Sepsis Consensus Conference consensus criteria were enrolled. The primary endpoint was agreement of pediatric severe sepsis between physician diagnosis and consensus criteria as measured using Cohen's ?. Secondary endpoints included characteristics and clinical outcomes for patients identified using physician diagnosis versus consensus criteria. Results: Of the 706 patients, 301 (42.6 %) met both definitions. The inter-rater agreement (? ± SE) between physician diagnosis and consensus criteria was 0.57 ± 0.02. Of the 438 patients with a physician's diagnosis of severe sepsis, only 69 % (301 of 438) would have been eligible to participate in a clinical trial of pediatric severe sepsis that enrolled patients based on consensus criteria. Patients with physician-diagnosed severe sepsis who did not meet consensus criteria were younger and had lower severity of illness and lower PICU mortality than those meeting consensus criteria or both definitions. After controlling for age, severity of illness, number of comorbid conditions, and treatment in developed versus resource-limited regions, patients identified with severe sepsis by physician diagnosis alone or by consensus criteria alone did not have PICU mortality significantly different from that of patients identified by both physician diagnosis and consensus criteria. Conclusions: Physician diagnosis of pediatric severe sepsis achieved only moderate agreement with consensus criteria, with physicians diagnosing severe sepsis more broadly. Consequently, the results of a research study based on consensus criteria may have limited generalizability to nearly one-third of PICU patients diagnosed with severe sepsis

Innovation, networking and the new industrial clusters: the characteristics of networks and local innovation capabilities in the Turkish industrial clusters

Elaborating on the literature on industrial districts, this paper suggests that innovation and networking are the two key issues, which provide the new generation industrial clusters' competitive capacity in the globalization process. The paper presents the findings on the innovative and networking capabilities of the three important industrial clusters of Turkey based on the data collected from the sample firms in each of these industrial clusters through in-depth interviews. The findings clearly show the importance of local and national networking as well as global linkages and confirm the positive relation between intensity of local networking and innovativeness. Moreover, the paper provides evidence that firms within global networks have higher numbers of innovations than firms with higher intensity of locally embedded linkages

Investigation of Antibacterial Activity and Biofilm Formation of Silicones Coated With Minocycline-Rifampicin, Silver Nitrate, and Nitrofurantoin for Short-term Utilization in In Vitro Urinary System Models

PMID = 2652297

Comparative effect of different polymerization techniques on residual monomer and hardness properties of PMMA-based denture resins

Purpose: The aim of this study was to compare the residual monomer and microhardness of poly(methyl methacrylate) (PMMA)–based denture resins processed by using autoclave and conventional water bath techniques. Methods: To determine the amount of residual methyl methacrylate (MMA) monomer, disk-shaped specimens (n=5) were prepared from 3 different acrylic resins (Meliodent, Paladent and Qc-20). Control groups were polymerized in water bath for 30 minutes at 100°C. The study groups were prepared in an autoclave device for 60°C/30 min followed 130°C/10 min and the other group for 60°C/30 min followed by 130°C/20 min. According to standard calibration curves, ultraviolet spectrophotometry at 230 nm was used to determine the residual monomer. For the Vickers hardness measurements, disk-shaped specimens (n=5) were prepared for each test group. Hardness measurements were performed with a Vickers hardness tester under a 4.91-N press load for a 30 seconds, after immersion in distilled water at 37ºC for 48 hours. The data were analyzed by ANOVA and Tukey HSD test (p0.05). Conclusions: The autoclave polymerization technique exhibited significantly lower residual monomer content and greater hardness than conventional heat polymerization. © 2014 Società Italiana Biomateriali

Effect of sealant agents on the color stability and surface roughness of nanohybrid composite resins

Statement of problem The effect of sealant agents on the surface roughness and color stability of nanohybrid composite resins is unknown. Purpose The purpose of this in vitro study was to evaluate the effect of sealant agents on the surface roughness and color stability of 4 nanohybrid composite resin materials. Material and methods Forty disks (10×2 mm) were fabricated for each nanohybrid composite resin material (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice) (N=160) and divided into 4 surface treatment groups: 1 conventional polishing (control) and 3 different sealant agent (Palaseal, Optiglaze, BisCover) coupling groups (n=10). The specimens were thermocycled, and surface roughness (R a ) values were obtained with a profilometer. Scanning electron microscope images were also recorded. CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color differences were calculated by the CIEDE 2000 (?E 00 ) formula. The data were statistically analyzed by 2-way ANOVA and by the Tukey HSD test (?=.05). Results The surface treatment technique significantly affected the R a values of the composite resins tested (P&lt;.001). The interaction between the surface treatment technique and composite resin material was also significant for ?E 00 values (P&lt;.05). Within the composite resin groups, significant decreases in R a were observed only for the Palaseal agent coupled composite resin groups (except Ice) compared with the control groups (P&lt;.05). Scanning electron microscope images revealed rougher surfaces with conventionally polished groups compared with test groups. Conventionally polished groups had the highest ?E 00 (3.09 to 3.49) values for each composite resin group, except for BisCover applied Clearfill Majesty (P&lt;.05). Within the composite resin groups, significant differences were observed between the color change seen with BisCover and other sealants for Clearfill Majesty composite resin (P&lt;.05). Conclusions Using Palaseal agent on all tested composite resins except for Ice produced smoother surfaces. All surface sealant agents provided less discoloration of nanohybrid composite resins after coffee staining compared with conventional polishing except for BisCover applied Clearfill Majesty composite resin. © 2016 Editorial Council for the Journal of Prosthetic Dentistr

Effect of surface sealant agents on the surface roughness and color stability of denture base materials

Statement of problem The effects of surface sealant agents on the surface roughness and color stability of denture base materials are unknown. Purpose The purpose of this in vitro study was to evaluate the effects of different polishing methods on the surface roughness and color stability of denture base materials. Material and methods A total of 120 specimens were fabricated from 2 poly(methyl methacrylate) (PMMA) and 1 polyamide denture base materials and divided into 4 groups (n=10 in each group) according to the applied surface treatment procedure: conventional polishing (control) and 3 surface sealant coupling methods. Surface roughness average (Ra) values were measured using a profilometer. Color parameters were measured using a spectrophotometer before and after being stained with coffee. Color differences (CIEDE 2000 [?E00]) were calculated. Data were statistically analyzed using 2-way ANOVA and Tukey honest significant difference test (?=.05). Results No statistically significant difference were found between surface roughness values of the control and those of the specimens treated using a surface sealant agent (P&gt;.05). The highest color difference was calculated for the polyamide control group. Statistically significant differences were found between the control group and the group treated with the polyamide surface sealant agent (P&lt;.05). Conclusions All specimens had a surface roughness value higher than the plaque accumulation threshold (0.20 µm). The color changes observed were clinically unacceptable, except for conventionally polished and one type of surface sealant applied microwave polymerized PMMA denture base material. © 2016 Editorial Council for the Journal of Prosthetic Dentistr

Effect of surface sealant agents on the surface roughness and color stability of denture base materials

Statement of problem The effects of surface sealant agents on the surface roughness and color stability of denture base materials are unknown. Purpose The purpose of this in vitro study was to evaluate the effects of different polishing methods on the surface roughness and color stability of denture base materials. Material and methods A total of 120 specimens were fabricated from 2 poly(methyl methacrylate) (PMMA) and 1 polyamide denture base materials and divided into 4 groups (n=10 in each group) according to the applied surface treatment procedure: conventional polishing (control) and 3 surface sealant coupling methods. Surface roughness average (Ra) values were measured using a profilometer. Color parameters were measured using a spectrophotometer before and after being stained with coffee. Color differences (CIEDE 2000 [?E00]) were calculated. Data were statistically analyzed using 2-way ANOVA and Tukey honest significant difference test (?=.05). Results No statistically significant difference were found between surface roughness values of the control and those of the specimens treated using a surface sealant agent (P&gt;.05). The highest color difference was calculated for the polyamide control group. Statistically significant differences were found between the control group and the group treated with the polyamide surface sealant agent (P&lt;.05). Conclusions All specimens had a surface roughness value higher than the plaque accumulation threshold (0.20 µm). The color changes observed were clinically unacceptable, except for conventionally polished and one type of surface sealant applied microwave polymerized PMMA denture base material. © 2016 Editorial Council for the Journal of Prosthetic Dentistr