ARTICLE | doi:10.20944/preprints202205.0026.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: analog circuit design; buffer amplifiers; offset voltage's systematic component; voltage followers; operational amplifiers; depletion-mode; СMOS; JFET; Si; GaAs; GaN
Online: 5 May 2022 (08:42:15 CEST)
The authors of the article performed computer simulation of buffer amplifiers (BA), which have medium and extremely small values of the offset voltage's systematic component (Voff), for different technological processes (Si, GaAs and GaN). The proposed control units are distinguished by a small number of elements and allow operation in the range of low and high temperatures. The variants of circuitry implementation of control units based on GaAs, GaN depletion-mode CMOS and JFET technological processes are considered. The results of the comparative modeling showed that the basic circuit of the BA on two field-effect transistors, when implemented on various modifications of GaN MOS and depletion-mode MOS transistors, provides sufficiently low values of the offset voltage's systematic component (less than 2 μV). The proposed BAs are designed for use in the structure of the Sallen-Key low-pass filter (LPF) when they are implemented both on mid-frequency Si CJFET and on GaAs microwave transistors. Low values of the LPF Voff have a positive effect on the effective capacity of the ADC. An example of switching on a BA in the JFET OpAmp structure based on the depletion-mode MOS input stage and a “folded” cascode, which, with 100% negative feedback, can be used in the Sallen-Key LPF, is considered. Computer simulation of the JFET/MOS OpAmp showed that the OpAmp has an open-loop voltage gain of 76-85dB, and its Voff is within 7µV in the temperature range from -60°C to +120°C. The presented circuitry of buffer amplifiers is intended, first of all, for the tasks of designing precision Sallen-Key low-pass filter (low-pass filter, high-pass filter, PF, RF).
ARTICLE | doi:10.20944/preprints202204.0235.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: operational amplifier; compensation of the systematic component of the zero offset voltage; differential stage; buffer amplifier; current mirror; reference current source; BJT transistors; GaAs transistors.
Online: 26 April 2022 (10:33:53 CEST)
The zero offset voltage in anti-aliasing low-pass filters (LPF) included at the ADC input has a significant effect on the effective bit rate of the ADC. The article discusses methods for minimizing the systematic component of the zero offset voltage (VOS) of operational amplifiers (Op-Amp) in the structure of the LPF, due to the degradation of the current gain of the base (b) of bipolar transistors for an extremely common subclass of Op-Amp with one high-impedance node. The methods of matching a high-impedance Op-Amp node and a buffer amplifier with the help of special correcting SCMp and SCMn multipolars are proposed. Methods of description and formation of the given coefficients of weak current asymmetry of typical Op-Amp functional units (current mirrors, input DS, buffer amplifiers, SRC, etc.) are presented. As an example, the results of computer simulation of GaAs Op-Amp with small VOS performed on JFET field and p-n-p bipolar transistors are given.
REVIEW | doi:10.20944/preprints202101.0418.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: health workforce; operational models; planning; skill mix; integration
Online: 21 January 2021 (12:35:46 CET)
Over the last decade, there has been a renewed interest in oral health workforce planning. The purpose of this review is to examine oral health workforce planning models on supply, demand and needs, mainly in respect to their data sources, modelling technique and use of skill mix. A search was carried out on PubMed, Web of Science, and Google Scholar databases for published scientific articles on oral health workforce planning models between 2010 to 2020. No restrictions were placed on the type of modelling philosophy, and all studies including supply, demand or needs based models were included. Rapid review methods guided the review process. Twenty-three studies from 15 different countries were included in the review. A majority were from high income countries (n=17). Dentists were the sole oral health workforce group modelled in 13 studies; only five studied included skill mix (allied dental personnel) considerations. The most common application of modelling was a workforce to population ratio or a needs-based demand weighted variant. Nearly all studies presented weaknesses in modelling process due to the limitations in data sources and/or non availability of necessary data to inform oral health workforce planning. Skill mix considerations in planning models were also limited to horizontal integration within oral health professionals. Planning for the future oral health workforce is heavily reliant on quality data being available for supply, demand and needs models. Integrated methodologies that expand skill mix considerations and account for uncertainty are essential for future planning exercises.
ARTICLE | doi:10.20944/preprints202007.0598.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: Reinforcement Learning; Simulation; Health Services Research; Operational Research
Online: 24 July 2020 (14:45:33 CEST)
Background and motivation: Combining Deep Reinforcement Learning (Deep RL) and Health Systems Simulations has significant potential, for both research into improving Deep RL performance and safety, and in operational practice. While individual toolkits exist for Deep RL and Health Systems Simulations, no framework to integrate the two has been established. Aim: Provide a framework for integrating Deep RL Networks with Health System Simulations, and to ensure this framework is compatible with Deep RL agents that have been developed and tested using OpenAI Gym. Methods: We developed our framework based on the OpenAI Gym framework, and demonstrate its use on a simple hospital bed capacity model. We built the Deep RL agents using PyTorch, and the Hospital Simulation using SimPy. Results: We demonstrate example models using a Double Deep Q Network or a Duelling Double Deep Q Network as the Deep RL agent. Conclusion: SimPy may be used to create Health System Simulations that are compatible with agents developed and tested on OpenAI Gym environments. GitHub repository of code: https://github.com/MichaelAllen1966/learninghospital
ARTICLE | doi:10.20944/preprints201803.0249.v1
Subject: Engineering, Other Keywords: chilled station, TRNSYS, control strategy, operational energy efficiency
Online: 29 March 2018 (11:49:11 CEST)
Taking an existing public building as an example, on the basis of the measured data, the mathematical model of each equipment module of the chilled station and the TRNSYS custom module are established. The mathematical model of “chilled station cooling capacity—equipment power” is proposed and established. The full-frequency control strategy based on device contribution rate is proposed and established to set up the Matlab control module of the chilled station. The TRNSYS simulation platform is used to simulate a public building chilled station in cooling season. The result shows that the season energy efficiency rate of the public building air-conditioning system is 2.15 times the original after applying the new control strategy.
ARTICLE | doi:10.20944/preprints201610.0078.v1
Subject: Earth Sciences, Environmental Sciences Keywords: calibration; validation; optical; instrument; processing; imagery; spatial; operational
Online: 19 October 2016 (10:59:29 CEST)
As part of the Copernicus programme of the European Union (EU), the European Space Agency (ESA) has developed and is currently operating the Sentinel-2 mission that is acquiring high spatial resolution optical imagery. This paper provides a description of the calibration activities and the current status of the mission products validation activities. Measured performances, from the validation activities, cover both Top-Of-Atmosphere (TOA) and Bottom-Of-Atmosphere (BOA) products. Results presented in this paper show the good quality of the mission products both in terms of radiometry and geometry and provide an overview on next mission steps related to data quality aspects.
ARTICLE | doi:10.20944/preprints202201.0279.v1
Subject: Social Sciences, Accounting Keywords: Paramedic; Violence; Qualitative Research; Operational Stress Injury; Mental Health
Online: 19 January 2022 (16:04:48 CET)
Purpose Violence against paramedics is a complex – but underreported – problem. Extant research suggests organizational culture may play a role in sustaining cultural norms that downplay the significance and limit reporting. Our objective was to qualitatively explore paramedics’ experience with violence, with particular emphasis on understanding how organizational culture contributes to under-reporting. Approach We surveyed paramedics from a single, large, urban service in Ontario, Canada, asking participants to describe their experiences with violence, including whether – and why or why not – the incidents were reported. Within a constructivist epistemology, we used inductive thematic analysis with successive rounds of coding to identify and then define features of organizational culture that limit reporting. Findings A total of 196 (33% of eligible) paramedics completed the survey. Fully 98% of participants disclosed having experienced some form of violence; however only a minority (40%) reported the incidents to management, or the police (21%). We defined a framework within which a lack of support from management, and consequences for offenders, implicitly positions the ability of paramedics to “brush off” violent encounters as an expected professional competency. Disclosing emotional or psychological distress in response to violent encounters invited questions as to whether the individual is personally suited to paramedic work. Originality While the extant research has indicated that underreporting is a problem, our findings shed light on why – a critical first step in addressing what has been described as a serious public health problem.
ARTICLE | doi:10.20944/preprints202106.0432.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: CMOS analog integrated circuit; FD-SOI; feedback; linearity; operational amplifier
Online: 16 June 2021 (10:20:52 CEST)
Negative feedback to the back gate of MOS devices available in FD-SOI technologies can be used to improve linearity of operational amplifiers. Two operational amplifiers designed and fabricated in a 22nm FD-SOI technology illustrate this technique, its advantages and limitations.
ARTICLE | doi:10.20944/preprints201810.0039.v1
Subject: Social Sciences, Other Keywords: Disaster, Operational Strategies, UAV, Drones, Man Made & Natural Disaster, CBRNE
Online: 3 October 2018 (11:08:43 CEST)
The disaster response operational strategies requires tool that a may provide time bound clear picture of potential spots. Natural disaster sometimes comes slowly like increment of water level resulting flood or early warning of tsunami whereas in manmade disasters like 1CBRNE attack or chemical accident or industrial structure collapse or leakage through a pipeline of some toxic hazardous gas requires very accurate and quick response strategies. 2Unmanned Aerial System is commercially used tools present in the market and also used by military organization for various operations throughout the world. The accuracy and time bound pictorial representation of the spots by these tow tools makes them very useful for providing clear picture of potential disaster sites and enabling decision makers to take decision on these representation. Apart of these the potential to deliver important material faster than any other mode also makes these equipment and technology a very important asset for making disaster risk reduction strategies. This paper elaborates the efficacy and utility of Unmanned Aerial System or Drones in developing robust and time bound strategies for disaster risk reduction. This paper also evaluates some experiences and describes some initiatives using Unmanned Aerial System to support disaster risk reduction strategies and post disaster decision making efforts.
ARTICLE | doi:10.20944/preprints201808.0288.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: analog feedback, operational amplifier (Opamp), buck converter, continuous conduction mode.
Online: 16 August 2018 (14:10:02 CEST)
In this paper, we discuss voltage control method for buck converter operating in continuous conduction mode (CCM) using analog feedback system. The aim of this work is to control the output voltage of a buck converter during the variation in load current. This is obtained using analog feedback made with operational amplifier (Opamp). However, the same technique can be applied to other DC-DC converters (e.g boost, buck-boost, cuk converter, etc) in CCM mode, but for the purpose of analysis buck converter is chosen as an example.
ARTICLE | doi:10.20944/preprints202212.0111.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: effective number of bits ADC; ADC driver; operational amplifier; maximum output voltage slew rate; signal delay in ADC driver; linear and nonlinear operational amplifier modes
Online: 7 December 2022 (02:26:54 CET)
The influence of linear and nonlinear modes of ADC driver on the operational amplifier (Op-Amp), which has different values of maximum output voltage slew rate, on the effective number of bits of ADC is considered. It is shown that the effective number of bits of ADC when op-amps on bipolar transistors with input signal amplitudes exceeding 50-100 mV is determined by the nonlinear modes of its input differential stage.
ARTICLE | doi:10.20944/preprints202210.0322.v1
Subject: Earth Sciences, Atmospheric Science Keywords: TC center detection; image processing; optical flow; operational radar network; ACTION
Online: 21 October 2022 (07:38:27 CEST)
This study presents the algorithm ACTION, defined as Automatic Center detection of Tropical cyclone (TC) using Image processing based on the Operational radar Network. Based on the high visibility of weather radar imagery, the TC’s motion vector is calculated from the continuous image change using optical flow, producing its rotation center as the TC’s center. The algorithm’s performance was verified for typhoons (TCs in the Northwestern Pacific) affecting the Korean Peninsula from 2018–2021 and showed a high detection rate of 80.8% within an error distance of 40 km compared to the best track of the Korea Meteorological Administration (KMA). The detection rate was 100% for typhoons with temporally consistent morphological characteristics. ACTION automatically generates TC center information upon the TC’s initial entry inside the observation radius even in the absence of uniform radar data. ACTION easily calculates using Open Source Computer Vision, performs in real time, and can be directly applied to rapidly generated weather radar images; hence, it is currently being utilized by the KMA. The high-temporal-resolution TC center information calculated through ACTION is expected to improve the efficiency of TC forecasting.
ARTICLE | doi:10.20944/preprints202011.0300.v1
Subject: Engineering, Automotive Engineering Keywords: Energy System; Large Scale; Day Ahead Market; Operational Planning; Unit Commitment
Online: 10 November 2020 (10:34:00 CET)
This paper proposes a mathematical model to simulate Day-ahead markets of large-scale multi-energy systems with high share of renewable energy. Furthermore, it analyses the importance of including unit commitment when performing such analysis. The results of the case study, which is performed for the North Sea region, show the influence of massive renewable penetration in the energy sector and increasing electrification of the district heating sector towards 2050, and how this impacts the role of other energy sources such as thermal and hydro. The penetration of wind and solar is likely to challenge the need for balancing in the system as well as the profitability of thermal units. The degree of influence of the unit commitment approach is found to be dependent on the configuration of the energy system. Overall, including unit commitment constraints with integer variables leads to more realistic behaviour of the units, at the cost of increasing considerably the computational time. Relaxing integer variables reduces significantly the computational time, without highly compromising the accuracy of the results. The proposed model, together with the insights from the study case, can be specially useful for system operators for optimal operational planning.
ARTICLE | doi:10.20944/preprints201806.0174.v1
Subject: Materials Science, Metallurgy Keywords: operational aircraft; skin corrosion; fatigue crack growth; stress corrosion cracking; buckling
Online: 12 June 2018 (08:36:13 CEST)
This paper studies the combined effect of corrosion and fatigue on the growth of cracks in aircraft and on the effect of skin corrosion and stress corrosion cracking on the load bearing capacity of rib stiffened aircraft wings. In this context it is shown that the growth of cracks from surface pitting, and also from intergranular cracking at a fastener hole, can be accurately computed using the Hartman-Schijve variant of the NASGRO crack growth equation. The examples studied support the lead crack approach, that has been independently developed by the USAF and the Australian Defence Science Technology Group, in which the growth of lead cracks is often exponential. In the case of skin corrosion it is shown that to be consistent with the US Joint Service Structural Guidelines (JSSG2006) assessment of its effect on the load bearing capacity of the wing should involve an assessment of whether at 115% DLL the remaining material exceeds the yield stress of the material.
ARTICLE | doi:10.20944/preprints201712.0053.v2
Subject: Social Sciences, Accounting Keywords: seasoned equity offerings; sustainable development; cumulative abnormal return; operational structure change
Online: 18 December 2017 (10:51:56 CET)
Sustainability is directly linked to firms’ survival in competitive markets. To survive, firms need extra capital, and seasoned equity offerings (SEOs) are one sustainability strategy. Additional resources from SEOs leads to changes in firms’ operational structure, which brings future sustainability. This study investigates whether there is sustainability in firms’ operational structure and the effects of sustainable development on operational performance and market reaction. We measure the operational structure change of firms as three proxies: 1) the rate of increase in the number of operating segments, 2) the Berry–Herfindahl index using the ratio of sales of each operating segment out of total sales, and 3) the size of net investment in plant and equipment. Our results show that operational structure change has a statistically significant and positive correlation with long-term operating performance. In addition, there is no significant stock price response at first, but the operating performance in the next term is perceived as a favorable factor after 3 years. The results show that there are different responses in the stock market toward operational structure change. The empirical results confirm that firms with SEO have sustainable development in operational structure and that markets recognize firms’ sustainability strategy arising from SEOs.
REVIEW | doi:10.20944/preprints201707.0031.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: thermal flow; harsh environment; operational modes; transduction; materials; properties and packaging
Online: 14 July 2017 (10:01:39 CEST)
Flow sensing in hostile environment is of increasing interest for applications in automotive, aerospace, and chemical and resource industries. Compared to their counterparts, thermal flow sensors are attractive candidates due to the ease of fabrication, lack of moving parts and higher sensitivity. Recently, a number of thermal flow sensor prototypes have been reported in the literature demonstrating the measurement of fluid flows under hostile conditions. This paper summarizes the concept of thermal flow sensing, operational modes and transduction mechanisms. Then, the choice of materials and their corresponding properties are presented in details. The paper also reports recent progress in the development of thermal flow sensors for harsh environment. In addition, the issues and considerations in packaging are reviewed. Finally, we conclude the review with the future prospects.
ARTICLE | doi:10.20944/preprints202110.0361.v1
Subject: Materials Science, General Materials Science Keywords: mortar; strength properties; operational safety; organic soils; weak soils; deformation modulus; dynamic deformations
Online: 25 October 2021 (15:33:03 CEST)
Abstract: During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of substrate on its strength and work during shooting should be examined. Until now in the Polish standardization documents was no clear description about the substrate parameters used for this kind of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of substrate and its geotechnical parameters. Therefore, the authors carried out analytical and experimental analysis of the use of geotechnical methods to determine the parameters of the substrate for mortar testing. The paper presents the proposed types of standardized soil and their research methods. Preliminary tests were also carried out using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the proposed methods of measuring the parameters of soil compressibility were determined.
ARTICLE | doi:10.20944/preprints201804.0162.v1
Subject: Earth Sciences, Atmospheric Science Keywords: operational forecast sytem; fire modeling; numerical weather prediction; high spatial reoslution; WRF-Fire
Online: 12 April 2018 (08:03:28 CEST)
Wildland fires are responsible for large socio-economic impacts. Fires affect the environment, damage structures, threaten lives, cause health issues, and involve large suppression costs. These impacts can be mitigated via accurate fire spread forecast to inform the incident management team. We show that a fire forecast system based on a numerical weather prediction (NWP) model coupled with a wildland fire behavior model can provide this forecast. This is illustrated with the Chimney Tops II wildland fire responsible for large socio-economic impacts. The system is run at high horizontal resolution (111 m) over the region affected by the fire to provide a fine representation of the terrain and fuel heterogeneities and explicitly resolve atmospheric turbulence. Our findings suggest that one can use the high spatial resolution winds, fire spread and smoke forecast to minimize the adverse impacts of wildland fires.
ARTICLE | doi:10.20944/preprints202107.0102.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: accelerometer; process monitoring; natural frequencies; ball burnishing; ultrasonic; piezoelectric; acoustic emission; operational deflection shape.
Online: 5 July 2021 (14:04:48 CEST)
In this paper, a resonant system that produces a movement of low amplitude and ultrasonic frequency is used to achieve the vibration assistance in a ball-burnishing process. A full vibration characterization of this process performed in a lathe was done. It is carried out by a new tool designed in the research group of the authors. Its purpose is to demonstrate that the machine and the tool do not have any resonance problem during the process and to prevent possible failures. The analysis of this dynamic behaviour permits to validate the suitability of the tool when it is anchored to a numerical control lathe. This is very important for its future industrial implementation. It is also intended to confirm that the system adequately transmits vibrations through the material. To do this, a methodology to validate the dynamic tool behaviour was developed. Several techniques that combine the usual and ultrasonic vibration ranges through static and dynamic measurements were merged: vibration and acoustic emission measurements. An operational deflection shape (ODS) exercise has been also performed. Results show the suitability of the tool used to transmit the assistance vibrations, and that no damage is produced in the material in any case.
ARTICLE | doi:10.20944/preprints202104.0506.v1
Subject: Engineering, Automotive Engineering Keywords: Structural health monitoring; bridge load testing; dynamic testing; operational modal analysis; experimental modal analysis
Online: 19 April 2021 (15:59:50 CEST)
The Sei Dareh Bridge is a cable-stayed bridge located in West Sumatra Province, Indonesia. The bridge, has a main span of 123 meters length and 9 meters wide, crosses the Batanghari River. Traffic load is transmitted through 4 prestressed cables to a 42.4 meter high pylon made of concrete. Bridge deck and traffic loads are directly supported by steel box girders as main beams that are reinforced laterally with cross beams IWF 800.300.16.24 and stringers IWF 350.350.12.19. This paper discusses static and dynamic testing on the bridge which aims to assess the feasibility before it is opened for public. Based on the test, it was concluded that the 73% static load could not be achieved because the deflection that occurred was beyond the allowable deflection. This is exacerbated by the sound of a loud clanging sound on the ST2-X1 prestressed cable when loading to 240 tons or 58% of the targeted load. In addition, this bridge is included in the "lazy bridge" category because it takes 24 hours to return to an undeformed condition after loading. As a recommendation for this bridge, it is necessary to carry out a structural health monitoring system (SHMS) regularly on the vehicle floor and cables.
ARTICLE | doi:10.20944/preprints202102.0600.v1
Subject: Engineering, Automotive Engineering Keywords: Tunnel boring machine (TBM); correlation models; mechanical and operational parameters; performance prediction; model validation
Online: 26 February 2021 (09:31:43 CET)
The study takes into account different classes of tunnel boring machines (TBMs), with the aim of identifying correlation models which are meant to estimate, at a preliminary design phase, the construction time of a tunnel and to evaluate the mechanical and operational parameters of the TBMs, starting from the knowledge of the tunnel length and/or the excavation diameter. To achieve this goal, first of all a database was created, thanks to the collection of the most meaningful technical parameters from a large number of tunnels; afterward, it was statistically analysed through Microsoft Excel. In a first phase, forecasting models were identified for the three types of machines investigated, separately for compact rocks (open TBM) and fractured rocks (single and double shield TBM). Then, the mechanical parameters collected through the database were analysed, with the aim of obtaining models that take into account, in addition to the type of TBM, the geological aspect, and the type of rock characterising the rock mass. Finally, the validation of the study was proposed in a real case, represented by the Moncenisio base tunnel, a work included in the new Turin–Lyon connection line. The estimated values were compared with the real ones, in order to verify the accuracy of the experimental models identified.
ARTICLE | doi:10.20944/preprints202010.0204.v1
Subject: Keywords: Legendre-Gould Hopper based Sheffer polynomials; Generating relations; Operational method; Monomiality principle; Determinantal definition
Online: 9 October 2020 (13:04:41 CEST)
In this article, the Legendre-Gould Hopper polynomials are combined with Sheffer sequences to introduce certain mixed type special polynomials. Generating functions, differential equations and certain other properties of Legendre-Gould Hopper based Sheffer polynomials are derived. Further, operational and integral representations providing connections between these polynomials and known special polynomials are established. Certain identities and results for some members of these new mixed polynomials are also obtained. Finally, the determinantal definitions of Legendre-Gould Hopper based Sheffer polynomials are also given.
Subject: Earth Sciences, Oceanography Keywords: Remote Sensing, Satellites, NOAA, CoastWatch, Oceanography, Training, Education, Operational Oceanography, ERDDAP, Value Added Provider
Online: 1 July 2019 (11:28:01 CEST)
Data from environmental satellites are underutilized in many branches of operational oceanography. Several challenges exist for potential users of satellite data that may impede or preclude employing satellite products in their work. Users outside of the satellite community often encounter difficulty in discovering the types of satellite measurements that are available, and determining which satellite products are best for operational activities. In addition, the large choice of satellite data providers, each with their own data access protocols and formats, can make data access confusing and inefficient. NOAA’s CoastWatch Program is designed to be a Value Added Provider, whose mission is to help make satellite data easier for users to access. With this objective the West Coast Node of CoastWatch developed the NOAA Ocean Satellite Course, which introduces scientists and resource managers to ocean satellite products, and provides them tools to facilitate data access when using ArcGIS or R software. These tools leverage upon the data services provided by ERDDAP, a data distribution system designed to make data access easier for both humans and machines. The course has been offered annually since 2006, and over 350 participants have taken it. Results of post-course surveys are analyzed to measure course effectiveness. Lessons learned from conducting these courses are summarized.
ARTICLE | doi:10.20944/preprints201805.0375.v1
Subject: Behavioral Sciences, Other Keywords: autism phenome; gut microbiome; behaviour reversal; meta-analysis; 16srRNA sequencing; operational taxonomic units (OTUs)
Online: 25 May 2018 (16:15:27 CEST)
Background: Gut-Brain-Axis provides bidirectional communicational route; imbalance of which can have pathophysiological consequences. It is a frontier in autism research, affects 85% of autistic children (NIH report). Their microbiome has few overall microbes and smaller number of health promising microbes than their neurotypical peers. We hypothesize autism gut might play a role in manifestation of autism behaviours and on treatment, can revert back to normal behaviour considerably. The aim is to better understand to what degree gut microbiota of autism subjects differs from controls and identify bacterial species present exclusively in autism. Materials and Methods: 16s-rRNA-sequence of autism-subjects were retrieved from the American Gut Project Archive. Taxonomic assignment was inferred by similarity based methods using Quantitative Insights Into Microbial Ecology (QIIME). Species abundance was characterized and co-occurrence network was built to infer species interaction using measures of diversity. Statistical parameters were considered to validate the findings. Result: A total of 206 (1.8%) of American Gut Project datasets onstituted of autistic samples. Various bacteria such as Akkermansia sp., and Prevotella sp., were harboured in higher abundance in autistic children with statistical significance than in controls. Conclusion: These findings indicate connecting-link between gut-microbiome-brain-axis and autistic behaviour which can result in improved management
REVIEW | doi:10.20944/preprints202009.0289.v1
Subject: Social Sciences, Geography Keywords: land surface temperature; operational land imager; thermal infrared sensor; normalized difference vegetation Index; geospatial technology
Online: 13 September 2020 (15:28:24 CEST)
Land Surface Temperature is a one of the key variable of Global climate changes and model which estimate radiating budget in heat balance as control of climate model. It is a major influenced factor by the ability of the surface emissivity. In this study, were used Landsat 8 satellite image that have Operational Land Imager and Thermal Infrared Sensor to calculate Land Surface Temperature through geospatial technology over Ampara district, Sri Lanka. The Land Surface Temperature was estimated with respect to Land Surface Emissivity and Normalized Difference Vegetation Index values determined from the Red and Near Infrared channels. Land Surface Emissivity was processed directly by the thermal Infrared bands. Pixels based calculation were used to effort at LANDSAT 8 images that thermal Band 10 various dates in this study. The results were achievable to compute Normalized Difference Vegetation Index, Land Surface Emissivity, and Land Surface Temperature with applicable manner to compare with land use/ land cover data. It determines and predicts the changes of surface temperature to favorable to decision making process for the society. Study area faces seasonal drought in Sri Lanka, the prediction method that how land can be efficiently used with the present condition. Therefore, the Land Surface Temperature estimation can prove whether new irrigation systems for agricultural activities or can transformed source of energy into useful form that introducing solar hubs for energy production in future.
ARTICLE | doi:10.20944/preprints202211.0565.v1
Subject: Engineering, Marine Engineering Keywords: Wave scatter table; operational measures; second generation intact stability criteria; hindcast wave scatter table; hindcast data
Online: 30 November 2022 (06:03:04 CET)
The operational measure (OM) of the Second-Generation Intact Stability Criteria (SGISC) is the initial step toward the design of a performance-based dynamic stability assessment of the ship by considering both the vessel’s operation, loading condition and weather parameters. The SGISC recommends the standard wave scatter table (WST) for the environmental data, an indefinite requirement for a simplified assessment pathway, which provides the probability of wave occurrence. The existing standard WST was developed based on the North Atlantic Ocean. This study aims to identify the discrepancy in the probability of wave occurrence in the IMO-recommended WST when compared with developed hindcast WST for smaller regions of the North Atlantic Ocean for the application of SGISC. The significant difference in the existing standard WST is identified when compared with hindcast data, especially across different seasons. A case study of OM on the C11 class post-Panamax container ship for excessive acceleration is provided to better represent the study. The identified limitation limits the use of standard WST in ship stability assessment. The study recommends using hindcast-based WST for SGISC applications that are region and season based. This recommendation is beneficial in improving the safety assessment by OM, given the data is reliable and available for the season and region-specific, and hence the accuracy of the ship stability can be improved while using for the SGISC OM assessment. Further, it makes the WST adhere to the actual framework of the SGISC, i.e., using existing environmental data for design assessment and improving the simplified stability analysis.
ARTICLE | doi:10.20944/preprints202008.0206.v1
Subject: Life Sciences, Microbiology Keywords: tongue microbiome; salivary microbiome; amplicon sequence variant (ASV); operational taxonomical unit (OTU); denoising; DADA2; taxonomic classifier
Online: 8 August 2020 (09:29:46 CEST)
The bacterial composition of oral samples has traditionally been determined by PCR amplicon sequencing of 16S rRNA genes. Recent amplicon sequence variant (ASV)-based analyses of 16S rRNA genes differ from that based on operational taxonomic unit (OTU) clustering in the way it deals with sequences having potential errors. However, little information is available on its application in oral microbiome studies. Here, we conducted ASV-based analysis of oral microbiome samples using QIIME 2. We investigated the optimal parameters for sequence denoising, using DADA2, and found the trimming of the first 20 nucleotides from 5′-end of both paired reads avoided excessive sequence loss during chimera removal. Truncating reads at positions 240–245 allowed the removal of low-quality sequences while maintaining sufficient length to merge matching paired ends. Taxonomic assignment, using the naïve Bayes classifier trained with the V3-V4 region of reference 16S rRNA sequences in the extended human oral microbiome database (eHOMD), resulted in bacterial compositions similar to those of OTU-based analyses. Contrary to OTU-based clustering, ASV-based analysis showed taxonomic abundance at the genus or species level to not differ significantly in tongue microbiomes, regardless of brushing. QIIME 2 can, therefore, be a standard pipeline for ASV-based analysis of oral microbiomes.
ARTICLE | doi:10.20944/preprints201612.0141.v1
Subject: Earth Sciences, Environmental Sciences Keywords: automated water extraction; landsat 8 Operational Land Imager (OLI); modified histogram bimodal method (MHBM); remote sensing
Online: 29 December 2016 (10:49:38 CET)
Surface water distribution extracted from remote sensing data has been used in water resource assessment, coastal management, and environmental change studies. Traditional manual methods for extracting water bodies cannot satisfy the requirements for mass processing of remote sensing data; therefore, accurate automated extraction of such water bodies has remained a challenge. The histogram bimodal method (HBM) is a frequently used objective tool for threshold selection in image segmentation. The threshold is determined by seeking twin peaks, and the valley values between them; however, automatically calculating the threshold is difficult because complex surfaces and image noise which lead to not perfect twin peaks (single or multiple peaks). We developed an operational automated water extraction method, the modified histogram bimodal method (MHBM). The MHBM defines the threshold range of water extraction through mass static data; therefore, it does not require the identification of twin histogram peaks. It then seeks the minimum values in the threshold range to achieve automated threshold. We calibrated the MHBM for many lakes in China using Landsat 8 Operational Land Imager (OLI) images, for which the relative error (RE) and squared correlation coefficient (R2) for threshold accuracy were found to be 2.1% and 0.96, respectively. The RE and root-mean-square error (RMSE) for the area accuracy of MHBM were 0.59% and 7.4 km2. The results show that the MHBM could easily be applied to mass time-series remote sensing data to calculate water thresholds within water index images and successfully extract the spatial distribution of large water bodies automatically.
ARTICLE | doi:10.20944/preprints202207.0391.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Antibiotic prescription; Outpatients; AWaRe classification; Ghana; SORT IT; Antimicrobial stewardship; Electronic Medical Records; Operational research; Antimicrobial resistance
Online: 26 July 2022 (07:47:52 CEST)
Background: Monitoring of antibiotic prescription practices in hospitals is essential to assess and facilitate appropriate use. This is relevant to halt the progression of antimicrobial resistance. Methods: Assessment of antibiotic prescribing patterns and completeness of antibiotic prescriptions among out-patients in 2021 was conducted at the University Hospital of Kwame Nkrumah University of Science and Technology in the Ashanti region of Ghana. We reviewed electronic medical records (EMR) of 49,660 patients who had 110,280 encounters in the year. Results: The patient encounters yielded 350,149 prescriptions. Every month, 33-36% of patient encounters resulted in antibiotic prescription, higher than the World Health Organization’s (WHO) recommended optimum of 27%. Almost half of the antibiotics prescribed belonged to WHO’s Watch group. Amoxicillin-clavulanic acid (50%), azithromycin (29%), ciprofloxacin (28%), metronidazole (21%), and cefuroxime (20%) were the most prescribed antibiotics. Antibiotic prescribing parameters (indication, name of drug, duration, dose, route and frequency) were documented in almost all prescriptions. Conclusions: Extending antimicrobial stewardship to the out-patient settings by developing standard treatment guidelines, an out-patient specific drug formulary and antibiograms can promote rational antibiotic use at the hospital. The EMR system of the hospital is a valuable tool for monitoring prescriptions that can be leveraged for future audits.
REVIEW | doi:10.20944/preprints201608.0045.v1
Subject: Engineering, Civil Engineering Keywords: railway infrastructure; high-speed rail; tracks; risk; management and monitoring; climate change; global warming; adaptation; operational readiness
Online: 5 August 2016 (05:11:02 CEST)
Warming of the climate system is unequivocal, and many of the observed changes are unprecedented over five decades to millennia. Globally the atmosphere and ocean is increasingly getting warmer, the amount of ice on the earth is decreasing over the oceans, and the sea level has risen. According to Intergovernmental Panel on Climate Change, the total increasing temperature globally averaged combined land and surface between the average of the 1850-1900 period and the 2003 to 2012 period is 0.78 °C (0.72 to 0.85). But should we prepare for such the relatively small change? The importance is not the mean of the warming but the considerable likelihood of climate change that could trigger extreme natural hazards. The impact and the risk of climate change associated with railway infrastructure have not been fully addressed in the literature due to the difference in local environmental parameters. On the other hand, the current railway network in Malaysia, over the last decade, has been significantly affected by severe weather conditions such as rainfall, lightning, wind and very high temperatures. Our research findings point out the extremes that can lead to asset system failure, degraded operation and ultimately, delays to train services. During the period of flood, the embankment of the track can be swept away and bridge can be demolished, while during drought, the embankment of the track can suffer from soil desiccation and embankment deterioration, high temperature increases the risk of track buckling and high winds can result in vegetation or foreign object incursion on to the infrastructure as well as additional quasi-static burden exerted. This review is of significant importance for planning and design of the newly proposed high speed rail link between Malaysia and Singapore.
ARTICLE | doi:10.20944/preprints202212.0282.v1
Subject: Engineering, Civil Engineering Keywords: Modal-based model updating, Bayesian model updating, System identification, Damage identification, Operational health monitoring, I-girder, Bridge, Aging.
Online: 15 December 2022 (10:10:39 CET)
The average age of in-service bridges has increased in recent years in the United States. To address this issue, structural health monitoring and damage identification approaches can be employed to prioritize maintenance/replacement of aging bridges. Among the damage identification and operational health monitoring approaches, finite element (FE) model updating methods can offer a solution to evaluate the mechanics-based characteristics of bridges. However, in a real-world setting, unidentifiability and mutual dependency between model parameters, modeling errors, especially due to boundary conditions, as well as ill-conditioning of updating algorithms can pose challenges to the application of FE model updating methods. To address these challenges, this study presents a two-step FE model updating approach. In the first step, modal-based model updating is used to estimate linear model parameters mainly related to the stiffness of boundary conditions and material properties. In the second step, in order to refine parameter estimation accounting for nonlinear response behavior of the bridge, a time-domain model updating is carried out. In this step, boundary conditions are fixed at their final estimates using modal-based model updating. To prevent the convergence of updating algorithm to local solutions, the initial estimates for nonlinear material properties are selected based on their corresponding final estimates in the modal-based model updating. To validate the applicability of the two-step FE model updating approach, a series of forced-vibration experiments are designed and carried out on a pair of decommissioned and deteriorated prestressed bridge I-girders. After carrying out the two-step FE model updating, the final estimates of concrete compressive strength are shown to provide reasonable assessment of the damage extent in the girders.
ARTICLE | doi:10.20944/preprints202209.0232.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Drug use review; Outpatients; Ghana; SORT IT; Quality indicators; Electronic Medical Records; Operational research; Rational use of medicines
Online: 15 September 2022 (13:39:06 CEST)
(1) Background: Rational use of medicines (RUM) and their assessment is important to ensure optimal use of resources and patient care in hospitals. These assessments are essential to identifying practice gaps for quality improvement. (2) Methods: Assessment of adherence to WHO/ International Network for Rational Use of Drugs core prescribing indicators among out-patients in 2021 was conducted at the University Hospital of the Kwame Nkrumah University of Science and Technology in the Ashanti region of Ghana. We reviewed electronic medical records (EMR) of 110,280 patient encounters in the year which resulted in 336,087 medicines prescribed. (3) Results: The average number of medicines prescribed per encounter was 3 with generics being prescribed in 76% of prescriptions. Injections were prescribed in 7% of encounters while 90% of medicines were from Ghana’s Essential Medicines List 2017. (4) Conclusions: With the exception of patient encounters with injections, all prescribing indicators assessed in this study did not meet WHO optimum levels providing targets for quality improvement in RUM. Implementing prescribing guides and policies, regular audits and feedback as well as continuous professional development training may help to improve prescribing practices in the hospital.
ARTICLE | doi:10.20944/preprints201902.0075.v1
Subject: Social Sciences, Economics Keywords: Big data; Data Standards; Entity Identifiers; Macroprudential Policy; Regulation; Risk Management; Dodd-Frank Act; Operational Efficiency; Systemic Risk
Online: 7 February 2019 (15:19:04 CET)
We examine the global legal entity identifier (LEI) system for the identification of participants in financial markets. Semi-structured interviews with data professionals reveal the many ways in which the LEI can improve both business process efficiency and counterparty and credit risk management. Larger social benefits, including monitoring of systemic financial risk, are achievable if it becomes the accepted universal standard for legal entity identification. Our interviews also review the substantial co-ordination and investment barriers to LEI adoption. To address these, a clear regulatory-led road map is needed for its future development with widespread application in regulatory reporting.
CONCEPT PAPER | doi:10.20944/preprints202111.0118.v1
Subject: Social Sciences, Accounting Keywords: Disruptive Technologies; Operational Breakeven; Altman’s Z-score; Enyi’s RSR; Going Concern; Market Induced Survival Ratio; Disruptive Technology Gains Index
Online: 5 November 2021 (11:31:53 CET)
Disruptive technologies (DT) have featured prominently in almost every human activity since the advent of computerization. The likely effects of DT on economic processes and human professions have and continue to generate fears and debates which spurred this investigation. To break away from the traditional approach the operational breakeven theory and the discriminant analysis techniques of Altman’s Z-score, and Enyi’s Relative Solvency Ratio were used to examine the relationship between firms’ market-induced-survival-ratio (MISR) and the disruptive technology gains index (DTGI) of seventy-three firms drawn from Nigeria and India. Descriptive and inferential statistics were used to analyze the data generated. The results showed that a sizeable number of firms has profited from the introduction of disruptive technologies with MISR and DTGI returning a 10% significant relationship while others are still struggling to measure up to the requirements of disruptive technologies in their chosen economic fields. The implication of this is that businesses must brace up and embrace digital transformation if they must stay afloat in this era of disruptive technologies. This study recommends a revolutionary approach to digital transformation in view of the fast pace of global integration while managers and business owners should adopt more pragmatic approach in appraising the operations and finances of a firm for effective results and timely responses to potential business challenges.
ARTICLE | doi:10.20944/preprints201909.0123.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Active case findings; Tuberculosis; TOUCH Agent; High TB burden area; TB Surveillance; 4S Screening; THALI Project; SORT IT; Operational Research
Online: 11 September 2019 (13:30:30 CEST)
Background: Active case finding for TB was implemented in selected sixty high TB burden wards of Kolkata, India. Community volunteers called TOUCH agents (TAs) identified and referred presumptive TB patients (PTBPs) to health facilities for TB diagnosis and treatment. We aimed to describe the ‘care cascade’ of PTBPs identified during July to December, 2018 and to explore the reasons for attrition as perceived by TAs and PTBPs. Methods: An explanatory mixed methods study with quantitative phase of cohort study using routinely collected data followed by descriptive qualitative study with in-depth interviews was conducted. Results: Of the 3, 86,242 individuals enumerated, 1132 (0.3%) PTBPs were identified. Only 713 (63.0%) PTBPs visited referred facility for TB diagnosis. TB was diagnosed in 177 (24.8%) and the number needed to screen for one TB was 2,183 individuals. The potential reasons for low yield were stigma and apprehension about TB, distrust about TA, wage loss for attending health facilities and substance abuse among PTBPs. Conclusion: The yield of ACF was suboptimal with low PTBP identification rate and high attrition rate. Interviewing each individual for symptoms of TB and supporting PTBPs for diagnosis through sputum collection and transport can be adopted to improve the yield.
ARTICLE | doi:10.20944/preprints201806.0408.v1
Subject: Earth Sciences, Geophysics Keywords: surface albedo; remote sensing; geostationary satellites; climate data records; essential climate variables; near real-time; operational processing; climate; land surface modeling
Online: 26 June 2018 (10:31:10 CEST)
Land surface albedo determines the splitting of downwelling solar radiation into components which are either reflected back to the atmosphere or absorbed by the surface. Land surface albedo is an important variable for the climate community and therefore was defined by the Global Climate Observing System (GCOS) as an Essential Climate Variable (ECV). Within the scope of the Satellite Application Facility for Land Surface Analysis (LSA SAF) of EUMETSAT, a near-real time (NRT) daily albedo product was developed in the last decade from observations provided by the SEVIRI instrument on board the geostationary satellites of the Meteosat Second Generation (MSG) series. In this study we present a new collection of albedo satellite products based on the same satellite data. The MSG Ten-day ALbedo (MTAL) product incorporates MSG observations over 31 days with a frequency of NRT production of 10 days. The MTAL collection is more dedicated to climate analysis studies compared to the daily albedo that was initially designed for the weather prediction community. For this reason, a homogeneous reprocessing of MTAL was done in 2018 to generate a Climate Data Record (CDR). The resulting product is called MTAL-R and has been made available to the community in addition to the NRT version of the MTAL product which has been available for several years. The retrieval algorithm behind the MTAL products comprises three distinct modules: one for atmospheric correction, one for daily inversion of a semi-empirical model of the bidirectional reflectance distribution function, and one for monthly composition that also determines surface albedo values. In this study the MTAL-R CDR is compared to ground surface measurements and concomitant albedo products collected by sensors on-board polar-orbiting satellites (SPOT-VGT and MODIS). We show that MTAL-R meets the quality requirements if MODIS or SPOT-VGT are considered as reference. This work leads to 14 years of production of geostationary land surface albedo products with a guaranteed continuity in the LSA SAF for the future years with the forthcoming third generation of European geostationary satellites.
ARTICLE | doi:10.20944/preprints202201.0198.v1
Subject: Social Sciences, Other Keywords: Public Safety Personnel; First Responders; Mental Disorders; Mental Health; Well-Being; Trauma; Operational Stress Injuries; Post-Traumatic Stress Injuries; Role Identity Theory; Qualitative Research
Online: 14 January 2022 (08:31:02 CET)
Role identity theory describes the purpose and meaning in life that comes, in part, from occupying social roles. While robustly linked to health and well-being, this may become, however, when an individual is unable to fulfil the perceived requirements of an especially salient role in the way that they believe they should. Amid high rates of mental illness among public safety personnel, we interviewed a purposely selected sample of 21 paramedics from a single service in Ontario, Canada to explore incongruence between an espoused and able-to-enact paramedic role identity. Situated in an interpretivist epistemology, and using successive rounds of thematic analysis, we developed a framework for role identity dissonance wherein chronic, identity-relevant disruptive events cause emotional and psychological distress. While some participants were able to recalibrate their sense of self and understanding of the role, for others, this dissonance was irreconcilable, contributing to disability and lost time from work. In addition to contributing a novel perspective on paramedic mental health and well-being, our work also offers a modest contribution to the theory in using the paramedic context as an example to consider identity disruption through chronic workplace stress.
ARTICLE | doi:10.20944/preprints202201.0368.v2
Subject: Behavioral Sciences, Clinical Psychology Keywords: Public Safety Personnel; First Responders; Mental Disorders; Mental Health; Well-Being; Trauma; Operational Stress Injuries; Post-Traumatic Stress Injuries; Resilience; Peer Support; Paramedics; Emergency Medical Services
Online: 27 January 2022 (13:57:44 CET)
There is growing recognition in research and policy of a mental health crisis among Canada’s paramedics but despite this, epidemiological surveillance of the problem is in its infancy. Just weeks before the emergence of the COVID-19 pandemic, we surveyed paramedics from a single, large, urban paramedic service in Ontario, Canada to assess for symptom clusters consistent with Post-Traumatic Stress Disorder (PTSD), major depressive disorder, and generalized anxiety disorder and to identify potential risk factors for each. In total, we received 589 completed surveys (a 97% completion rate) and found that 11% screened positive for PTSD, 15% for depression, and 15% for anxiety, with 1 in 4 active-duty paramedics screening positive for any of the three as recently as February 2020. In adjusted analyses, the risk of a positive screen varied as a function of employment classification, gender, self-reported resilience, and previous experience as a member of the service’s peer support team. Our findings support the position that paramedics screen positive for mental disorders at high rates – a problem likely to have worsened since the onset of the COVID-19 pandemic. We echo the calls of researchers and policymakers for urgent action to support paramedic mental health in Canada.
ARTICLE | doi:10.20944/preprints202202.0080.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: anthropometry; biomechanics; coordinate measuring machines; in vivo; kinematics; mechanical sensors; sensor arrays; human ankle model, operational amplifiers; pose estimation; position measurement; rehabilitation robotics; biomedical informatics; product of exponentials formula; Riemmanian manifolds
Online: 7 February 2022 (11:50:24 CET)
The human ankle is a complex joint, most commonly represented as talocrural and subtalar axes. It is difficult to locate and take in vivo measurements of the ankle joint. There are no instruments for patients lying on a bed or the floor; that can be used in outdoor or remote sites. We have developed a "Turmell-meter" to address these issues. We started with the study of ankle anatomy and anthropometry, then we used the product of exponentials’ formula to visualize the movements. Furthermore, we built a prototype using human proportions and statistics. For pose estimation, we used a trilateration method by applying tetrahedral geometry. Additionally, we computed the axis direction by fitting 3D circles, plotting the manifold and chart as an ankle joint model. We presented the results of simulations, a prototype comprising 45 parts, specifically designed draw-wire sensors, and electronics. Finally, we tested the device by capturing positions and fitting them into the bi-axial ankle model as a Riemannian manifold. The Turmell-meter is intended to be a hardware platform for human ankle joint axis estimation, it is adjustable and has an easy setup. The proposed model has the properties of a chart in a geometric manifold, we provided the details