scholarly journals Design an Adjustable Narrow Correlator to Track GPS Signals

2019 ◽  
Vol 63 (4) ◽  
pp. 312-319
Author(s):  
Ali Albu-Rghaif ◽  
Saad A. Salman ◽  
Haider Ali Jasim Alshamary
Keyword(s):  
Receiver Design ◽  
Gps Receiver ◽  
New Approach ◽  
Accurate Localization ◽  
Main Challenge ◽  
Delay Lock Loop ◽  
Challenging Environment ◽  
Multipath Signals ◽  
The Impact ◽  
Tracking Synchronization

Multipath signals problem is still the main challenge for the global positioning system (GPS) receiver to obtain an accurate localization measurement. However, many techniques have been developed to mitigate the impact of these undesired signals at the expense of adding a burden to the GPS receiver design. Even though, none of the techniques in the works of literature was able to solve the loose signal lock issue efficiently. In this piece of work, we used a new approach to maintain the tracking synchronization when the receiver moves from outdoors to indoors /harsh environment. We design a dynamic narrow correlator in the delay lock loop, which made the space between the early and late correlators adjusted according to the receiver’s location. Consequently, this will enable the receiver to keep tracking the received GPS signal in a challenging environment and reduce the thrashing the available resources (power/processing) to acquire the GPS signal again. The results show that the ranging error has been reduced in comparison with a traditional narrow correlator, as well as the bit transition in the in-phase arm has been also maintained.

A multiscale homogenization procedure to predict the elasto-viscoplastic behavior of polymer-based nanocomposites

2021 ◽  
pp. 096739112110233
Author(s):  
Mohammad Hassan Shojaeefard ◽  
Abolfazl Khalkhali ◽  
Sharif Khakshournia
Keyword(s):  
Design Procedure ◽  
Polymeric Matrix ◽  
Elastic Behavior ◽  
Algorithm Optimization ◽  
Multiphase Materials ◽  
Rate Dependent ◽  
Main Challenge ◽  
Compressive Loads ◽  
Structural Parts ◽  
The Impact

It has been demonstrated that adding a few percent of nanoscale reinforcements, leads to remarkable improvement in mechanical properties of the polymers such as stiffness, damping, and energy absorption. These lightweight materials are attractive substitutes for the heavy metallic structural parts in the automotive, military, aerospace and many other industries. However, due to complexity of these multiphase materials, accurate modeling of their behavior in real loading cases is still ambiguous. The impact simulation is a vital step in design procedure of a vehicle, where a strain rate-dependent model of its components is required. In this paper, an elasto-viscoplastic modeling procedure of the polymer-based nanocomposites, assuming the elastic behavior of the nano-phase is presented; whereas the polymeric matrix deformation is dependent to the loading rate and is characterized by the method of Genetic algorithm optimization-based fitting to the experimental observations. By introducing a modified Halpin-Tsai method, the nanocomposite is then modeled as a homogenized material where the modification algorithm is the main challenge. A combination of approaches including parametric analysis, central composite design of experiments and response surface method is proposed to modify the tangent modulus of the polymeric matrix to be passed as the input to the Halpin-Tsai equations. Finally, the procedure is implemented to a set of epoxy-GNP nanocomposites under unidirectional compressive loads with different rates and the stress-strain curves are predicted with a decent precision.

Survey Data Quality in Analyzing Harmonized Indicators of Protest Behavior: A Survey Data Recycling Approach

2021 ◽  
pp. 000276422110216
Author(s):  
Kazimierz M. Slomczynski ◽  
Irina Tomescu-Dubrow ◽  
Ilona Wysmulek
Keyword(s):  
Data Processing ◽  
Data Quality ◽  
Survey Data ◽  
A Priori ◽  
Data Sets ◽  
New Approach ◽  
Survey Quality ◽  
Survey Error ◽  
Ex Post ◽  
The Impact

This article proposes a new approach to analyze protest participation measured in surveys of uneven quality. Because single international survey projects cover only a fraction of the world’s nations in specific periods, researchers increasingly turn to ex-post harmonization of different survey data sets not a priori designed as comparable. However, very few scholars systematically examine the impact of the survey data quality on substantive results. We argue that the variation in source data, especially deviations from standards of survey documentation, data processing, and computer files—proposed by methodologists of Total Survey Error, Survey Quality Monitoring, and Fitness for Intended Use—is important for analyzing protest behavior. In particular, we apply the Survey Data Recycling framework to investigate the extent to which indicators of attending demonstrations and signing petitions in 1,184 national survey projects are associated with measures of data quality, controlling for variability in the questionnaire items. We demonstrate that the null hypothesis of no impact of measures of survey quality on indicators of protest participation must be rejected. Measures of survey documentation, data processing, and computer records, taken together, explain over 5% of the intersurvey variance in the proportions of the populations attending demonstrations or signing petitions.

Telephone-based consultation in an acute eye clinic service: A patient satisfaction survey

2021 ◽  
pp. 112067212110307
Author(s):  
Julia Sieberer ◽  
Patrick Hughes ◽  
Indy Sian
Keyword(s):  
Healthcare Professionals ◽  
Medical Specialties ◽  
New Approach ◽  
High Satisfaction ◽  
Negative Comments ◽  
Patient Responses ◽  
Set Up ◽  
Strongly Agree ◽  
The Impact ◽  
Park Hospital

Objectives: The coronavirus pandemic has forced healthcare staff across all medical specialties to adapt new and different ways of working. A new approach has been set up in the Acute Referral Clinic (ARC) at Musgrove Park Hospital and a survey has been conducted to measure the impact of the new method on patient and healthcare professionals’ satisfaction with the new service. Methods: A telephone-based consultation was introduced in ARC at Musgrove Park Hospital in March 2020 and patients were instructed to fill out a questionnaire containing eight items using a Likert Scale 1 (‘very poor/disagree’) to 4 (‘very good/strongly agree’) plus two boxes for open positive and negative comments respectively. Likewise a questionnaire was designed in order to assess the healthcare professionals’ satisfaction using the new approach. Data collection took place over a two month period between the end of March 2020 and end of May 2020. The data underwent quality control and was analysed using descriptive statistics. Results: Patient responses illustrated high satisfaction scores with an overall rating of very good (89.4%). The healthcare professionals’ rating of the service was good (28.6% – ‘very good/strongly agree’, 57.1% – ‘good/agree’). The safety rating of the new approach was overall rated ‘very good’ with 90.4% and 71.4% of patients and healthcare professionals respectively. Conclusions: The telephone consultations introduced in the wake of COVID-19 are well accepted by both patients and doctors. There are some limitations of the approach, foremost being consultation time and clinic space but these do not outweigh the general benefit of this format amidst a pandemic setting.

scholarly journals Geoinformation Technologies in Support of Environmental Hazards Monitoring under Climate Change: An Extensive Review

2021 ◽  
Vol 10 (2) ◽  
pp. 94
Author(s):  
Andreas Tsatsaris ◽  
Kleomenis Kalogeropoulos ◽  
Nikolaos Stathopoulos ◽  
Panagiota Louka ◽  
Konstantinos Tsanakas ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Monitoring ◽  
Environmental Hazards ◽  
Geographic Information ◽  
Added Value ◽  
Spatial Data Analysis ◽  
Anthropogenic Factors ◽  
Geospatial Technologies ◽  
Main Challenge ◽  
The Impact

Human activities and climate change constitute the contemporary catalyst for natural processes and their impacts, i.e., geo-environmental hazards. Globally, natural catastrophic phenomena and hazards, such as drought, soil erosion, quantitative and qualitative degradation of groundwater, frost, flooding, sea level rise, etc., are intensified by anthropogenic factors. Thus, they present rapid increase in intensity, frequency of occurrence, spatial density, and significant spread of the areas of occurrence. The impact of these phenomena is devastating to human life and to global economies, private holdings, infrastructure, etc., while in a wider context it has a very negative effect on the social, environmental, and economic status of the affected region. Geospatial technologies including Geographic Information Systems, Remote Sensing—Earth Observation as well as related spatial data analysis tools, models, databases, contribute nowadays significantly in predicting, preventing, researching, addressing, rehabilitating, and managing these phenomena and their effects. This review attempts to mark the most devastating geo-hazards from the view of environmental monitoring, covering the state of the art in the use of geospatial technologies in that respect. It also defines the main challenge of this new era which is nothing more than the fictitious exploitation of the information produced by the environmental monitoring so that the necessary policies are taken in the direction of a sustainable future. The review highlights the potential and increasing added value of geographic information as a means to support environmental monitoring in the face of climate change. The growth in geographic information seems to be rapidly accelerated due to the technological and scientific developments that will continue with exponential progress in the years to come. Nonetheless, as it is also highlighted in this review continuous monitoring of the environment is subject to an interdisciplinary approach and contains an amount of actions that cover both the development of natural phenomena and their catastrophic effects mostly due to climate change.

Impact of a New Teaching and Learning Approach in an Introductory Programming Course

2017 ◽  
Vol 55 (6) ◽  
pp. 789-819 ◽  
Author(s):  
Sohail Iqbal Malik ◽  
Jo Coldwell-Neilson
Keyword(s):  
Teaching And Learning ◽  
Positive Impact ◽  
Dropout Rates ◽  
Success Rates ◽  
Final Exam ◽  
Introductory Programming ◽  
New Approach ◽  
Course Materials ◽  
Didactic Triangle ◽  
The Impact

High failure and dropout rates are reported in introductory programming (IP) courses in different studies despite extensive research attempting to address the issue. In this study, we introduced an ADRI (Approach, Deployment, Result, Improvement) approach in the teaching and learning process of an IP course to improve learning and success rates. All three entities of the didactic triangle (student, instructor, and content) were involved in the research to better understand and execute the proposed approach. The IP course materials were redesigned based on the ADRI approach, and an editor was developed to promote the new approach and encourage students to complete the various stages required in the approach. Two surveys were conducted, and final exam grades over four semesters were compared with determine the impact of including the ADRI approach in the course. We concluded that the ADRI approach provides a positive impact on outcomes that the students achieved during the course. It engages students in practicing their programming skills and provides a new presentation style for examples and exercises which discourages students from taking programming shortcuts. It not only helps to reduce the failure and, significantly, the dropout rates from the IP course but also impacts positively on all students who passed the IP course.

A New Approach for Estimating the Observation Impact in Ensemble–Variational Data Assimilation

2018 ◽  
Vol 146 (2) ◽  
pp. 447-465 ◽  
Author(s):  
Mark Buehner ◽  
Ping Du ◽  
Joël Bédard
Keyword(s):  
Data Assimilation ◽  
Forecast Error ◽  
Forecast Model ◽  
Variational Data Assimilation ◽  
Observation Error ◽  
New Approach ◽  
Regional Prediction ◽  
Observation Impact ◽  
Adjoint Approach ◽  
The Impact

Abstract Two types of approaches are commonly used for estimating the impact of arbitrary subsets of observations on short-range forecast error. The first was developed for variational data assimilation systems and requires the adjoint of the forecast model. Comparable approaches were developed for use with the ensemble Kalman filter and rely on ensembles of forecasts. In this study, a new approach for computing observation impact is proposed for ensemble–variational data assimilation (EnVar). Like standard adjoint approaches, the adjoint of the data assimilation procedure is implemented through the iterative minimization of a modified cost function. However, like ensemble approaches, the adjoint of the forecast step is obtained by using an ensemble of forecasts. Numerical experiments were performed to compare the new approach with the standard adjoint approach in the context of operational deterministic NWP. Generally similar results are obtained with both approaches, especially when the new approach uses covariance localization that is horizontally advected between analysis and forecast times. However, large differences in estimated impacts are obtained for some surface observations. Vertical propagation of the observation impact is noticeably restricted with the new approach because of vertical covariance localization. The new approach is used to evaluate changes in observation impact as a result of the use of interchannel observation error correlations for radiance observations. The estimated observation impact in similarly configured global and regional prediction systems is also compared. Overall, the new approach should provide useful estimates of observation impact for data assimilation systems based on EnVar when an adjoint model is not available.

Discussion and documentation of future care: a before-and-after study examining the impact of an alternative approach to recording treatment decisions on advance care planning in an acute hospital

2017 ◽  
Vol 10 (2) ◽  
pp. e12-e12 ◽  
Author(s):  
Alexandra C Malyon ◽  
Julia R Forman ◽  
Jonathan P Fuld ◽  
Zoë Fritz
Keyword(s):  
End Of Life ◽  
Advance Care Planning ◽  
Treatment Decisions ◽  
Care Planning ◽  
New Approach ◽  
Significance Level ◽  
Oncology Ward ◽  
Future Care ◽  
Advance Care ◽  
The Impact

ObjectiveTo determine whether discussion and documentation of decisions about future care was improved following the introduction of a new approach to recording treatment decisions: the Universal Form of Treatment Options (UFTO).MethodsRetrospective review of the medical records of patients who died within 90 days of admission to oncology or respiratory medicine wards over two 3-month periods, preimplementation and postimplementation of the UFTO. A sample size of 70 per group was required to provide 80% power to observe a change from 15% to 35% in discussion or documentation of advance care planning (ACP), using a two-sided test at the 5% significance level.ResultsOn the oncology ward, introduction of the UFTO was associated with a statistically significant increase in cardiopulmonary resuscitation decisions documented for patients (pre-UFTO 52% to post-UFTO 77%, p=0.01) and an increase in discussions regarding ACP (pre-UFTO 27%, post-UFTO 49%, p=0.03). There were no demonstrable changes in practice on the respiratory ward. Only one patient came into hospital with a formal ACP document.ConclusionsDespite patients’ proximity to the end-of-life, there was limited documentation of ACP and almost no evidence of formalised ACP. The introduction of the UFTO was associated with a change in practice on the oncology ward but this was not observed for respiratory patients. A new approach to recording treatment decisions may contribute to improving discussion and documentation about future care but further work is needed to ensure that all patients’ preferences for treatment and care at the end-of-life are known.

Foreign Capital, Natural Resource Rents and Financial Development: A New Approach

2020 ◽  
pp. 097215092096136
Author(s):  
Muhammad Shahbaz ◽  
Mohammad Ali Aboutorabi ◽  
Farzaneh Ahmadian Yazdi
Keyword(s):  
Financial Development ◽  
Natural Resource ◽  
Capital Accumulation ◽  
Foreign Capital ◽  
New Approach ◽  
Resource Rents ◽  
Long Run ◽  
Natural Resource Rents ◽  
Rich Countries ◽  
The Impact

This article explores the impact of financial development on the ‘natural resources rents–foreign capital accumulation nexus’ in selected natural resource–rich countries during 1970Q1–2016Q4. In doing so, we propose a new approach by applying the autoregressive distributed lag (ARDL) rolling regression technique for our empirical purpose. The results show that financial development has a positive and significant effect on the way natural resource rents affect foreign capital in the case of Australia, Chile, Ecuador, Egypt and Peru in both the short run and the long run. We achieve the same results in the case of Colombia and Iran too, but just in the long run. Also, short-term and long-term negative effects of financial development on the rents–foreign capital nexus are witnessed just in the case of Algeria. We provide some empirical evidence for further robustness of our findings. Finally, we suggest that there is a necessity for the development of the financial system in natural resource–rich countries to reach higher levels of foreign capital, which has a crucial role in their economic growth.

Effects of State Dissociation on Objectively and Subjectively assessed Memory Disturbances

2006 ◽  
Vol 34 (3) ◽  
pp. 319-331 ◽  
Author(s):  
Nicole Buck ◽  
Merel Kindt ◽  
Marcel van den Hout
Keyword(s):  
Information Processing ◽  
Traumatic Experience ◽  
Spider Phobia ◽  
New Approach ◽  
Perceptual Memory ◽  
Aversive Events ◽  
Memory Representations ◽  
State Dissociation ◽  
The Impact ◽  
Experimentally Induced

Dissociation often occurs after a traumatic experience and has detrimental effects on memory. If these supposed detrimental effects are the result of disturbances in information processing, not only subjectively assessed but also objectively assessed memory disturbances should be observed. Most studies assessing dissociation and memory in the context of trauma have studied trauma victims. However, this study takes a new approach in that the impact of experimentally induced state dissociation on memory is investigated in people with spider phobia. Note that the aim of the present study was not to test the effect of trauma on memory disturbances. We found indeed significant relations between state dissociation and subjectively assessed memory disturbances: intrusions and self-rated memory fragmentation. Moreover, although no relation was found between state dissociation and experimenter-rated memory fragmentation, we observed a relation between state dissociation and experimenter-rated perceptual memory representations. These results show that state dissociation indeed has detrimental effects on the processing of aversive events.

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