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141.
142.
How much does knowledge regarding a certain spoken word or phrase help with its localization? This is a very fundamental question for speech processing, and will be partially addressed in this paper. In particular, this work will utilize prior information regarding the contents of a speech signal in order to improve the artificial localization of it using Time delay of arrival (TDOA) between two microphones. The prior information, which is used to develop a very simple frequency-selective phase transform (FPT), increases the effective SNR by only using a subset of the highest SNR frequencies in the Phase Transform. Simulations in a reverberant environment show that the proposed approach can more robustly and accurately localize speech sources. For 20 ms signal segments, it is shown that using a subset of 45 percent of available speech frequency bins is superior to using 30, 60, or 100, where using 100 corresponds to the standard Phase Transform.  相似文献   
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144.
Inventory models use a set of parameters to establish their respected optimal policy. Such parameters are information items that have to be generated (obtained) and, therefore, there is a cost for obtaining them. Traditional inventory models simply ignore the existence of this cost and, therefore, the established optimal policies by these models may not be necessarily optimal in practice. In this paper, based on the requirements dictated by a real-world project, we analyze the impact of information update decisions for a specific class of inventory model (a single-period inventory model). The main difference between the presented model in this paper and newsboy problem is the presence of an inventory update decision and its effect on other inventory decisions. That is to decide when inventory-related information should be updated, how much should be ordered, and what is the maximum level of demand that can be promised to the customers. We formulate these decisions and develop mathematical methods to find the corresponding optimal policies.  相似文献   
145.
Poly(amido amine) (PAMAM) dendrimer‐polyethylene oxide (PEO) nanofibers as dendrimeric‐polymeric composite nanofibers were prepared via electrospinning of PEO solution containing PAMAM dendrimer. The resultant fibers were characterized by means of transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The morphology and thermal properties of PEO nanofibers with and without PAMAM dendrimer were compared and the effect of PAMAM concentration on morphology and thermal properties of the resultant fibers was studied. The fibers had a size range of about 400–1300 nanometer in diameter with aureole morphology in most regions. The phase change temperature, phase transition heat, and the crystallinity of the produced composite fibers were determined by DSC analyses. TGA was also used to confirm the presence of PAMAM and to determine the amount of it within the fibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   
146.
In this paper a general review on different membrane processes and membrane reactors was done. As the main aim of this paper is to review the application of membrane processes in petrochemical industry, processes such as olefin/paraffin separation, light solvent separation, solvent dewaxing, phenol and aromatic recovery, dehydrogenation, oxidative coupling of methane and steam reforming of methane were discussed in detail. Besides, separation using polymer-inorganic nano composite membranes and wastewater treatment using membrane bio-reactors were reviewed.  相似文献   
147.
Novel layered materials based on molybdenum oxide have been synthesized using three amino-carboxylate ligands; terephetalic acid, p-aminobezoic acid and diaminobenzene. On the basis of X-ray diffraction, scanning electron microscopy, thermogravimetry, and infrared results, the insertion of organic ligands into the interlayer space of molybdenum oxide has been proposed. Moreover, the influence of organic guests on the oxide structure and also their catalytic performance are discussed. Furthermore, fabrication of the nanostructured molybdenum oxide is achieved by calcinations of these hybrid materials at 600 °C. Somewhat oriented nanoplatelets are viewed with different catalytic activity.  相似文献   
148.
BACKGROUND: Iron-deficiency anemia is the most prevalent nutritional deficiency worldwide. Iron-deficiency anemia has particular negative consequences on women in their childbearing years, and its prevention is a high priority in most health systems. OBJECTIVE: This interventional study assessed the effect of nutrition education on hematologic indices, iron status, nutritional knowledge, and nutritional practices of high-school girls in Iran. METHODS: Sixty healthy 16- to 18-year-old girls were randomly selected from two high schools in the city of Ahvaz and divided into two equally matched groups, one that received nutrition education, and one that did not. The education group received instruction in face-to-face sessions, group discussions, and pamphlets for 2 months. The control group did not receive any information during the study. Hematologic tests, corpuscular indices, and serum ferritin levels were measured at baseline and after 2 months. Food-frequency questionnaires were administered and histories taken, clinical signs of nutritional deficiencies observed, anthropometric measurements taken, nutritional knowledge tested, practices determined, and lifestyle questionnaires administered to all subjects. RESULTS: There were no statistically significant differences in any baseline characteristics between the two groups. Scores for nutritional knowledge and practices of the education group were significantly higher after two months compared with the baseline (31.4 +/- 6 vs. 24.3 +/- 5.9 points, p < .001, and 31.2 +/- 5 vs. 28.4 +/- 5.7 points, p < .05, respectively). The scores in the control group showed no significant changes from baseline to 2 months. Mean corpuscular volume values were elevated in the education group (p < .001) but not in the control group. However, in the control group, serum ferritin concentrations showed about a 17% drop at the end of the study (p < .004). There were no changes in other hematologic, lifestyle, clinical, or anthropometric data compared with baseline after completion of the study in both groups. CONCLUSION: These findings indicate that nutritional education can improve knowledge of healthy nutrition and lifestyle choices. Focused nutritional education using available resources and correcting current dietary habits in a vulnerable group of young women may result in dietary changes that can ultimately improve iron intake.  相似文献   
149.
In the current work, suitability of hyperbranched polyglycerol as a high loading catalyst support is demonstrated. A polyglycerol‐supported manganese‐salen complex (chemzyme) is applied as a homogeneous catalyst in the epoxidation of 6‐cyano‐2,2‐dimethylchromene. The recyclability of the corresponding catalyst was investigated in repetitive batch experiments as well as a continuous operation of the reaction in an ultrafiltration membrane reactor. An enhanced stability of the catalyst in repetitive batches was observed as a result of immobilization whereby the total turnover number increased from 23 in a single batch to 80 in four repetitive batches. To enable continuous operation, a continuously operated, stirred tanked reactor (CSTR) was equipped with an ultrafiltration membrane (MPF‐50) and a retention of 98% was determined. The continuous chemzyme membrane reactor was operated over the course of 20 residence times. After approximately 12 residence times, the steady state was reached yielding 70% conversion as well as an enantiomeric excess up to 92%. A space‐time yield (sty) of 458 g L −1 d−1 and a turnover frequency (TOFreaction) of up to 18 h−1 was reached in the steady state. It was determined that the total turnover number (TTN) was enhanced by a factor of 10 from 24 (batch) up to 240 for 20 residence times in CSTR operation.  相似文献   
150.
This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of ginger intake on weight loss, glycemic control and lipid profiles among overweight and obese subjects. We searched the following databases through November 2017: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as Standardized Mean Difference (SMD) with 95% Confidence Intervals (95% CI). Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I2). Overall, 14 studies were included in the meta-analyses. Fourteen RCTs with 473 subjects were included in our meta-analysis. The results indicated that the supplementation with ginger significantly decreased body weight (BW) (SMD ?0.66; 95% CI, ?1.31, ?0.01; P = 0.04), waist-to-hip ratio (WHR) (SMD ?0.49; 95% CI, ?0.82, ?0.17; P = 0.003), hip ratio (HR) (SMD ?0.42; 95% CI, ?0.77, ?0.08; P = 0.01), fasting glucose (SMD ?0.68; 95% CI, ?1.23, ?0.05; P = 0.03) and insulin resistance index (HOMA-IR) (SMD ?1.67; 95% CI, ?2.86, ?0.48; P = 0.006), and significantly increased HDL-cholesterol levels (SMD 0.40; 95% CI, 0.10, 0.70; P = 0.009). We found no detrimental effect of ginger on body mass index (BMI) (SMD ?0.65; 95% CI, ?1.36, 0.06; P = 0.074), insulin (SMD ?0.54; 95% CI, ?1.43, 0.35; P = 0.23), triglycerides (SMD ?0.27; 95% CI, ?0.71, 0.18; P = 0.24), total- (SMD ?0.20; 95% CI, ?0.58, 0.18; P = 0.30) and LDL-cholesterol (SMD ?0.13; 95% CI, ?0.51, 0.24; P = 0.48). Overall, the current meta-analysis demonstrated that ginger intake reduced BW, WHR, HR, fasting glucose and HOMA-IR, and increased HDL-cholesterol, but did not affect insulin, BMI, triglycerides, total- and LDL-cholesterol levels.  相似文献   
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