A Graphical Approach to GPS Software-Defined Receiver Implementation

Global positioning system (GPS) software-defined receivers (SDRs) offer many advantages over their hardwarebased counterparts, such as flexibility, modularity, and upgradability. A typical GPS receiver is readily expressible as a block diagram, making a graphical approach a natural choice for implementing GPS SDRs. This paper presents a real-time, graphical implementation of a GPS SDR, consisting of two modes: acquisition and tracking. The acquisition mode performs a twodimensional fast Fourier transform (FFT)-based search over code offsets and Doppler frequencies. The carrier-aided code tracking mode consists of the following main building blocks: correlators, code and carrier phase detectors, code and carrier phase filters, a code generator, and a numerically-controlled oscillator. The presented GPS SDR provides an abstraction level that enables future research endeavors.Aerospace Engineering and Engineering Mechanic

Tightly-Coupled Opportunistic Navigation for Deep Urban and Indoor Positioning

A strategy is presented for exploiting the frequency stability, transmit location, and timing information of ambient radio-frequency “signals of opportunity” for the purpose of navigating in deep urban and indoor environments. The strategy, referred to as tightly-coupled opportunistic navigation (TCON), involves a receiver continually searching for signals from which to extract navigation and timing information. The receiver begins by characterizing these signals, whether downloading characterizations from a collaborative online database or performing characterizations on-the-fly. Signal observables are subsequently combined within a central estimator to produce an optimal estimate of position and time. A simple demonstration of the TCON strategy focused on timing shows that a TCONenabled receiver can characterize and use CDMA cellular signals to correct its local clock variations, allowing it to coherently integrate GNSS signals beyond 100 seconds.Aerospace Engineering and Engineering Mechanic

Performance Evaluation of IFAS System Using Honeycomb PVC Media

Recently, Egypt is facing serious problems caused by the deterioration of effluent quality of many wastewater treatment plants (WWTP) especially in rural areas. Unexpected rapid increase in population associated with the increase of organic loading are the main factors causing the failure in operation for many WWTPs. Absence of periodic maintenance and lack of operators’ experience in these rural areas make the situation worse. Many WWTP are recently under rehabilitation and upgrading for the above reasons, however decision makers are facing a real challenge due to the space-limit in many cases. The integrated fixed film activated sludge (IFAS) system has recently proved to be an effective choice to expand the WWTP capacity for growing communities, enhance nitrogen removal and comply with more stringent effluent limits with small footprint. In this research, an IFAS pilot-scale reactor is constructed to optimize its application in upgrading conventional activated sludge (CAS) plants. The effect of carrier position, hydraulic retention time (HRT) and organic loading rate (OLR) on the biological treatment efficiency and nutrient removal compared to CAS process are studied. IFAS configurations with no media, vertical position and cross flow media position are tested with 4, 8 and 12 hours retention times and organic loading rates of 0.84 and 1.44 Kg COD/m3.day. Keywords: Integrated fixed film IFAS, biological nitrogen removal, honeycomb PVC media DOI: 10.7176/CER/11-2-06 Publication date:March 31st 2019

Impact of Cytotoxin-Associated Gene Product-A Positive Helicobacter Pylori Strains on Micro-albuminuria in Type 2 Diabetes

Introduction: Available data on the possible association between Helicobacter Pylori (H. pylori) infection and diabetes mellitus (DM) are contradictory. The prevalence of cytotoxin associated gene product A (cagA) positive H. pylori is high in Egypt. This study aims to examine its association with type 2 DM, and its effect on glycemic control and the occurrence of microalbuminuria. Methods: The study involved 98 dyspeptic type 2 diabetic patients and 102 dyspeptic non-diabetic subjects who underwent upper gastrointestinal tract endoscopy in Zagazig university hospital. H. pylori infection was diagnosed by histopathology and/or culture. The presence of cagA positive strains was confirmed by polymerase chain reaction (PCR) and gel electrophoresis. Fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c) and urinary albumin excretion ratio (UAER) were compared between infected and non-infected diabetic patients. Results: Diabetic patients had similar age and gender distribution but significantly higher body mass index (BMI) compared to controls. The prevalence of H. pylori infection (54.1% versus 56.9%, P = 0.3) and the prevalence of cagA positive H. pylori strains (40.8% versus 36.3%, P =0.1) were not significantly different between the two groups. Diabetic patients infected with cagA positive H. pylori strains had higher mean FBS (199±22 versus 163±20, P=0.00), higher mean HbA1c (8.6±0.8 versus 6.3±0.8, P=0.00) and higher rate of microalbuminuria (67.5% versus 10.3%, P=0.00) than non infected diabetic patients. Conclusion: H. pylori infection with cagA positive strains was similarly common in dyspeptic diabetic patients and controls. It was associated with poorer glycemic control and higher rates of microalbuminuria in diabetic subjects. Key words: cagA positive strains; Diabetes mellitus; Helicobatcer pylori; Microalbuminuri

Content & Watkins's account of natural axiomatizations

This paper briefly recounts the importance of the notion of natural axiomatizations for explicating hypothetico-deductivism, empirical significance, theoretical reduction, and organic fertility. Problems for the account of natural axiomatizations developed by John Watkins in Science and Scepticism and the revised account developed by Elie Zahar are demonstrated. It is then shown that Watkins's account can be salvaged from various counter-examples in a principled way by adding the demand that every axiom of a natural axiomatization should be part of the content of the theory being axiomatized. The crucial point here is that content cannot simply be identified with the set of logical consequences of a theory, but must be restricted to a proper subset of the consequence set. It is concluded that the revised Watkins account has certain advantages over the account of natural axiomatizations offered in Gemes (1993)

Enhanced situational awareness and decision support for operators of future distributed power network architectures

This paper describes scenarios proposed for a control room decision support system aimed at future power network operators. The purpose is to consider the requirements of the future control room from the perspective of the operator under the conditions of a significant frequency excursion incident. The control room visualisation and decision support functionality for aiding the operator in restoring the frequency to its target value will be considered. The analysis takes place within the Web-of-Cells framework, adopted to deal with power system control through a web of subsystems, called cells, which are highly automated, and operated by Cell Operators

Role of MRP-1 and GST-Pi in MDR and their inhibition by indomethacin in AML

Background: MDR continues to be a major challenge to effective chemotherapeutic interventions against cancer. Defining major factor contributing to MDR and inhibiting their action may thus be used for reversing MDR.Aim: This work aimed to evaluate the role played by MRP-1 and GST-Pi in MDR, and to explore the possible role of indomethacin as an inhibitor of chemotherapy resistance in patients with AML.Subjects and methods: The study included 2 groups, one included 20 healthy volunteers and the second included 50 AML patients. All patients received one cycle of standard induction chemotherapy, then regrouped according to their response to either CR group or unremitted group. Unremitted patients received a second cycle of chemotherapy combined with indomethacin. From each subject a blood sample was drawn before and after the 1st cycle of chemotherapy and after the 2nd cycle. From blood, mononuclear cells were separated, mRNA was extracted, and RT-PCR was carried out to detect GST-Pi and MRP-1 gene expression.Results: GST-Pi expression in CR group was 60% before therapy that significantly decreased to 30% after therapy. While in unremitted group, its expression significantly increased from 30% before to 80% after therapy. GST-Pi positive patients had a significantly lower overall and disease free survival time than GST Pi negative patients (P = 0.000 and 0.039, respectively). While MRP-1 expression was so low (20%) and remained unchanged after therapy in both groups. MRP-1 expression did not affect overall or disease free survival. Taking indomethacin with 2nd cycle of chemotherapy in unremitted patients resulted in a significant inhibition of GST-Pi expression and a significantly longer overall survival time than those taking 2nd cycle chemotherapy alone (P =0.034).Conclusion: MRP-1 is not likely to contribute to MDR, while GST-Pi might have a role in MDR phenotype in AML patients. Furthermore, GST-Pi inhibition significantly reduced MDR in AML patients.Keywords: AML; MDR; GST-Pi; MRP-1; Indomethacin; RT-PC