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Article ; Online: Through-Life Maintenance Cost of Digital Avionics

Ahmed Raza / Vladimir Ulansky

Applied Sciences, Vol 11, Iss 2, p

2021 Volume 715

Abstract: Modern avionics can account for around 30% of the total cost of the aircraft. Therefore, it is essential to reduce the operational cost of avionics during a lifetime. This article addresses the critical scientific problem of creating the appropriate ... ...

Abstract	Modern avionics can account for around 30% of the total cost of the aircraft. Therefore, it is essential to reduce the operational cost of avionics during a lifetime. This article addresses the critical scientific problem of creating the appropriate maintenance models for digital avionics systems that significantly increase their operational effectiveness. In this research, we propose the lifecycle cost equations to select the best option for the maintenance of digital avionics. The proposed cost equations consider permanent failures, intermittent faults, and false-positives occurred during the flight. The lifecycle cost equations are determined for the warranty and the post-warranty interval of aircraft operation. We model several maintenance options for each period of service. The cost equations consider the characteristics of the permanent failures and intermittent faults, conditional probabilities of in-flight false-positive and true-positive as well as the cost of different maintenance operations, duration of the flight, and some other parameters. We have demonstrated that a three-level post-warranty maintenance variant with a detector of intermittent faults is the best because it minimizes the total expected maintenance cost several folds compared to other maintenance options.
Keywords	avionics maintenance ; intermittent fault ; permanent failure ; in-flight false-positive ; automated test equipment ; mean time between unscheduled removals ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	670
Language	English
Publishing date	2021-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: In Response.

Varughese, Shane / Ahmed, Raza

Anesthesia and analgesia

2022 Volume 134, Issue 5, Page(s) e27

Language	English
Publishing date	2022-04-15
Publishing country	United States
Document type	Letter ; Comment
ZDB-ID	80032-6
ISSN	1526-7598 ; 0003-2999
ISSN (online)	1526-7598
ISSN	0003-2999
DOI	10.1213/ANE.0000000000005896
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Article ; Online: Forecasting real exchange rate (REER) using artificial intelligence and time series models

Moiz Qureshi / Nawaz Ahmad / Saif Ullah / Ahmed Raza ul Mustafa

Heliyon, Vol 9, Iss 5, Pp e16335- (2023)

2023

Abstract: Forecasting is an attractive topic in every field of study because no one knows the exact nature of the underlying phenomena, but it can be guessed using mathematical functions. As the world progresses towards technology and betterment, algorithms are ... ...

Abstract	Forecasting is an attractive topic in every field of study because no one knows the exact nature of the underlying phenomena, but it can be guessed using mathematical functions. As the world progresses towards technology and betterment, algorithms are updated to understand the nature of ongoing phenomena. Machine learning (ML) algorithms are an updated phenomenon used in every task aspect. Real exchange rate data is assumed to be one of the significant components of the business market, which plays a pivotal role in learning market trends. In this work, machine learning models, i.e., the Multi-layer perceptron model (MLP), Extreme learning machine (ELM) model and classical time series models are used, Autoregressive integrated moving average (ARIMA) and Exponential Smoothing (ES) model to model and predict the real exchange rate data set (REER). The data under consideration is from January 2019 to June 2022 and comprises 864 observations. This study split the data set into training and testing and applied all stated models. This study selects a model that meets the Key Performance Indicators (KPI) criteria. This model was selected as the best candidate model to predict the behaviour of the real exchange rate data set.
Keywords	C12 ; C22 ; C45 ; C53 ; E47 ; Science (General) ; Q1-390 ; Social sciences (General) ; H1-99
Subject code	006
Language	English
Publishing date	2023-05-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
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Article ; Online: Is there an EKC between economic growth and air pollutant emissions in SAARC countries? Evidence from disaggregated analysis.

Farooq, Usama / Ul-Haq, Jabbar / Cheema, Ahmed Raza

Environmental science and pollution research international

2023 Volume 30, Issue 44, Page(s) 99979–99991

Abstract: The manufacturing and construction (M&C) sector not only plays a vital role in promoting economic growth, but is also a significant contributor to global air pollution. Growing concerns regarding air pollutant emissions necessitate a more disaggregated ( ... ...

Abstract	The manufacturing and construction (M&C) sector not only plays a vital role in promoting economic growth, but is also a significant contributor to global air pollution. Growing concerns regarding air pollutant emissions necessitate a more disaggregated (i.e., sectoral) investigation in order to identify the major contributors. This study employs aggregated and disaggregated data to determine the fundamental effects of economic growth (i.e., overall growth and sectoral growth) on air pollutant emissions (APE) (specifically, PM2.5 and PM10 released by the M&C sector) in SAARC economies between 1995 and 2018. It assesses the environmental Kuznets curve (i.e., inverted U-shaped and N-shaped) using the feasible generalized least squares (FGLS), panel-corrected standard errors (PCSE), and generalized method of moments (GMM) techniques. The sectoral analysis reveals the presence of an N-shaped EKC while the overall analysis indicates an inverted U-shaped EKC. Population, financial development (FD), and merchandise exports (MX) have no influence on the estimates. Population and FD increase APE in all models, whereas the effects of MX vary between models. As SAARC economies are capital-deficient, these economies can adopt unbalanced environmental protection policies. First, focus on major contributing sectors (e.g., M&C sector) to curb APE, then focus on less emitting sectors in turn. By implementing pollution reduction strategies on M&C sector activities, governments may reach their threshold (peak) points earlier than expected. A reduction in APE is impossible without rigorous monitoring and application. Being capital-deficient nations and given the collective nature of the problem, a Transboundary Haze/Pollution agreement is required to solve this issue.
MeSH term(s)	Animals ; Air Pollutants/analysis ; Economic Development ; Air Pollution/analysis ; Environmental Pollution ; Carbon Dioxide/analysis ; Hominidae
Chemical Substances	Air Pollutants ; Carbon Dioxide (142M471B3J)
Language	English
Publishing date	2023-08-25
Publishing country	Germany
Document type	Journal Article
ZDB-ID	1178791-0
ISSN	1614-7499 ; 0944-1344
ISSN (online)	1614-7499
ISSN	0944-1344
DOI	10.1007/s11356-023-29363-2
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Article: Zero-Effort Ambient Heart Rate Monitoring Using Ballistocardiography Detected Through a Seat Cushion: Prototype Development and Preliminary Study.

Malik, Ahmed Raza / Boger, Jennifer

JMIR rehabilitation and assistive technologies

2021 Volume 8, Issue 2, Page(s) e25996

Abstract: Background: Cardiovascular diseases are a leading cause of death worldwide and result in significant economic costs to health care systems. The prevalence of cardiovascular conditions that require monitoring is expected to increase as the average age of ...

Abstract	Background: Cardiovascular diseases are a leading cause of death worldwide and result in significant economic costs to health care systems. The prevalence of cardiovascular conditions that require monitoring is expected to increase as the average age of the global population continues to rise. Although an accurate cardiac assessment can be performed at medical centers, frequent visits for assessment are not feasible for most people, especially those with limited mobility. Monitoring of vital signs at home is becoming an increasingly desirable, accessible, and practical alternative. As wearable devices are not the ideal solution for everyone, it is necessary to develop parallel and complementary approaches. Objective: This research aims to develop a zero-effort, unobtrusive, cost-effective, and portable option for home-based ambient heart rate monitoring. Methods: The prototype seat cushion uses load cells to acquire a user's ballistocardiogram (BCG). The analog signal from the load cells is amplified and filtered by a signal-conditioning circuit before being digitally recorded. A pilot study with 20 participants was conducted to analyze the prototype's ability to capture the BCG during five real-world tasks: sitting still, watching a video on a computer screen, reading, using a computer, and having a conversation. A novel algorithm based on the continuous wavelet transform was developed to extract the heart rate by detecting the largest amplitude values (J-peaks) in the BCG signal. Results: The pilot study data showed that the BCG signals from all five tasks had sufficiently large portions to extract heart rate. The continuous wavelet transform-based algorithm for J-peak detection demonstrated an overall accuracy of 91.4% compared with electrocardiography. Excluding three outliers that had significantly noisy BCG data, the algorithm achieved 94.6% accuracy, which was aligned with that of wearable devices. Conclusions: This study suggests that BCG acquired through a seat cushion is a viable alternative to wearable technologies. The prototype seat cushion presented in this study is an example of a relatively accessible, affordable, portable, and unobtrusive zero-effort approach to achieve frequent home-based ambient heart rate monitoring.
Language	English
Publishing date	2021-05-31
Publishing country	Canada
Document type	Journal Article
ZDB-ID	2798120-4
ISSN	2369-2529
ISSN	2369-2529
DOI	10.2196/25996
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Article ; Online: Environmental and Occupational Considerations of Anesthesia: A Narrative Review and Update.

Varughese, Shane / Ahmed, Raza

Anesthesia and analgesia

2021 Volume 133, Issue 4, Page(s) 826–835

Abstract: With an estimated worldwide volume of 266 million surgeries in 2015, the call for general inhalation anesthesia is considerable. However, widely used volatile anesthetics such as N2O and the highly fluorinated gases sevoflurane, desflurane, and ... ...

Abstract	With an estimated worldwide volume of 266 million surgeries in 2015, the call for general inhalation anesthesia is considerable. However, widely used volatile anesthetics such as N2O and the highly fluorinated gases sevoflurane, desflurane, and isoflurane are greenhouse gases, ozone-depleting agents, or both. Because these agents undergo minimal metabolism in the body during clinical use and are primarily (≥95%) eliminated unchanged via exhalation, waste anesthetic gases (WAGs) in operating rooms and postanesthesia care units can pose a challenge for overall elimination and occupational exposure. The chemical properties and global warming impacts of these gases vary, with atmospheric lifetimes of 1-5 years for sevoflurane, 3-6 years for isoflurane, 9-21 years for desflurane, and 114 years for N2O. Additionally, the use of N2O as a carrier gas for the inhalation anesthetics and as a supplement to intravenous (IV) anesthetics further contributes to these impacts. At the same time, unscavenged WAGs can result in chronic occupational exposure of health care workers to potential associated adverse health effects. Few adverse effects associated with WAGs have been documented, however, when workplace exposure limits are implemented. Specific measures that can help reduce occupational exposure and the environmental impact of inhaled anesthetics include efficient ventilation and scavenging systems, regular monitoring of airborne concentrations of waste gases to remain below recommended limits, ensuring that anesthesia equipment is well maintained, avoiding desflurane and N2O if possible, and minimizing fresh gas flow rates (eg, use of low-flow anesthesia). One alternative to volatile anesthetics may be total intravenous anesthesia (TIVA). While TIVA is not associated with the risks of occupational exposure or atmospheric pollution that are inherent to volatile anesthetic gases, clinical considerations should be weighed in the choice of agent. Appropriate procedures for the disposal of IV anesthetics must be followed to minimize any potential for negative environmental effects. Overall, although their contributions are relatively low compared with those of other human-produced substances, inhaled anesthetics are intrinsically potent greenhouse gases and pose a risk to operating-room personnel if not properly managed and scavenged. Factors to reduce waste and minimize the future impact of these substances should be considered.
MeSH term(s)	Air Pollutants, Occupational/adverse effects ; Anesthesia, Inhalation/adverse effects ; Anesthetics, Inhalation/administration & dosage ; Anesthetics, Inhalation/adverse effects ; Animals ; Conservation of Natural Resources ; Environmental Monitoring ; Global Warming ; Greenhouse Effect ; Greenhouse Gases/adverse effects ; Humans ; Medical Waste ; Medical Waste Disposal ; Occupational Exposure/adverse effects ; Occupational Exposure/prevention & control ; Occupational Health ; Ozone Depletion ; Risk Assessment ; Risk Factors
Chemical Substances	Air Pollutants, Occupational ; Anesthetics, Inhalation ; Greenhouse Gases ; Medical Waste ; Medical Waste Disposal
Language	English
Publishing date	2021-04-05
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	80032-6
ISSN	1526-7598 ; 0003-2999
ISSN (online)	1526-7598
ISSN	0003-2999
DOI	10.1213/ANE.0000000000005504
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Article ; Online: Two-Terminal Electronic Circuits with Controllable Linear NDR Region and Their Applications

Vladimir Ulansky / Ahmed Raza / Denys Milke

Applied Sciences, Vol 11, Iss 9815, p

2021 Volume 9815

Abstract: Negative differential resistance (NDR) is inherent in many electronic devices, in which, over a specific voltage range, the current decreases with increasing voltage. Semiconductor structures with NDR have several unique properties that stimulate the ... ...

Abstract	Negative differential resistance (NDR) is inherent in many electronic devices, in which, over a specific voltage range, the current decreases with increasing voltage. Semiconductor structures with NDR have several unique properties that stimulate the search for technological and circuitry solutions in developing new semiconductor devices and circuits experiencing NDR features. This study considers two-terminal NDR electronic circuits based on multiple-output current mirrors, such as cascode, Wilson, and improved Wilson, combined with a field-effect transistor. The undoubted advantages of the proposed electronic circuits are the linearity of the current-voltage characteristics in the NDR region and the ability to regulate the value of negative resistance by changing the number of mirrored current sources. We derive equations for each proposed circuit to calculate the NDR region’s total current and differential resistance. We consider applications of NDR circuits for designing microwave single frequency oscillators and voltage-controlled oscillators. The problem of choosing the optimal oscillator topology is examined. We show that the designed oscillators based on NDR circuits with Wilson and improved Wilson multiple-output current mirrors have high efficiency and extremely low phase noise. For a single frequency oscillator consuming 33.9 mW, the phase noise is −154.6 dBc/Hz at a 100 kHz offset from a 1.310 GHz carrier. The resulting figure of merit is −221.6 dBc/Hz. The implemented oscillator prototype confirms the theoretical achievements.
Keywords	controllable negative differential resistance ; cascode current mirror ; Wilson current mirror ; oscillator ; voltage-controlled oscillator ; phase noise ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	620
Language	English
Publishing date	2021-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: A Blockchain-Based Secret-Data Sharing Framework for Personal Health Records in Emergency Condition

Ahmed Raza Rajput / Qianmu Li / Milad Taleby Ahvanooey

Healthcare, Vol 9, Iss 2, p

2021 Volume 206

Abstract: Blockchain technology is the most trusted all-in-one cryptosystem that provides a framework for securing transactions over networks due to its irreversibility and immutability characteristics. Blockchain network, as a decentralized infrastructure, has ... ...

Abstract	Blockchain technology is the most trusted all-in-one cryptosystem that provides a framework for securing transactions over networks due to its irreversibility and immutability characteristics. Blockchain network, as a decentralized infrastructure, has drawn the attention of various startups, administrators, and developers. This system preserves transactions from tampering and provides a tracking tool for tracing past network operations. A personal health record (PHR) system permits patients to control and share data concerning their health conditions by particular peoples. In the case of an emergency, the patient is unable to approve the emergency staff access to the PHR. Furthermore, a history record management system of the patient’s PHR is required, which exhibits hugely private personal data (e.g., modification date, name of user, last health condition, etc.). In this paper, we suggest a healthcare management framework that employs blockchain technology to provide a tamper protection application by considering safe policies. These policies involve identifying extensible access control, auditing, and tamper resistance in an emergency scenario. Our experiments demonstrated that the proposed framework affords superior performance compared to the state-of-the-art healthcare systems concerning accessibility, privacy, emergency access control, and data auditing.
Keywords	personal health record ; emergency access ; access control ; blockchain ; hyperledger fabric ; hyperledger composer ; Medicine ; R
Subject code	306
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Pathways to prevention

Hussain Ahmed Raza / Mohummad Hassan Raza Raja / Muhammad Mussab Khakwani / Minahil Khakwani / Bushra Jamil

Journal of the Pakistan Medical Association (2023)

insights on stemming HIV outbreaks in Larkana, Pakistan

2023

Abstract: In the past two decades, Pakistan has faced multiple human immunodeficiency virus outbreaks, with Larkana appearing to be the hub of such outbreaks. While the previous Larkana outbreaks happened in high-risk populations, the alarming outbreak in 2019 ... ...

Abstract	In the past two decades, Pakistan has faced multiple human immunodeficiency virus outbreaks, with Larkana appearing to be the hub of such outbreaks. While the previous Larkana outbreaks happened in high-risk populations, the alarming outbreak in 2019 occurred in a low-risk paediatric population, raising several concerning questions. Human immunodeficiency virus infections spilling into the general population is indicative of a steady increase in the number of cases, and the failure of control strategies to stem the concentrated epidemic from evolving. Although several causative factors have been identified from previous outbreaks, the one that occurred in 2019 may have been influenced by an additional, hitherto unexplored factor; child sexual abuse. The current narrative review was planned to summarise human immunodeficiency virus risk factors and causes identified in previous Larkana epidemics, to explore potential reasons for the outbreaks in children, ---Continue
Keywords	HIV ; Epidemics ; Children ; Risk factors ; Pakistan ; Medicine ; R
Subject code	360
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	Pakistan Medical Association
Document type	Article ; Online
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Article ; Online: Bacterial Symbionts Confer Thermal Tolerance to Cereal Aphids Rhopalosiphum padi and Sitobion avenae

Muhammad Zeeshan Majeed / Samy Sayed / Zhang Bo / Ahmed Raza / Chun-Sen Ma

Insects, Vol 13, Iss 231, p

2022 Volume 231

Abstract: High-temperature events are evidenced to exert significant influence on the population performance and thermal biology of insects, such as aphids. However, it is not yet clear whether the bacterial symbionts of insects mediate the thermal tolerance ... ...

Abstract	High-temperature events are evidenced to exert significant influence on the population performance and thermal biology of insects, such as aphids. However, it is not yet clear whether the bacterial symbionts of insects mediate the thermal tolerance traits of their hosts. This study is intended to assess the putative association among the chronic and acute thermal tolerance of two cereal aphid species, Rhopalosiphum padi (L.) and Sitobion avenae (F.), and the abundance of their bacterial symbionts. The clones of aphids were collected randomly from different fields of wheat crops and were maintained under laboratory conditions. Basal and acclimated CTmax and chronic thermal tolerance indices were measured for 5-day-old apterous aphid individuals and the abundance (gene copy numbers) of aphid-specific and total (16S rRNA) bacterial symbionts were determined using real-time RT-qPCR. The results reveal that R. padi individuals were more temperature tolerant under chronic exposure to 31 °C and also exhibited about 1.0 °C higher acclimated and basal CTmax values than those of S. avenae . Moreover, a significantly higher bacterial symbionts’ gene abundance was recorded in temperature-tolerant aphid individuals than the susceptible ones for both aphid species. Although total bacterial (16S rRNA) abundance per aphid was higher in S. avenae than R. padi , the gene abundance of aphid-specific bacterial symbionts was nearly alike for both of the aphid species. Nevertheless, basal and acclimated CTmax values were positively and significantly associated with the gene abundance of total symbiont density, Buchnera aphidicola , Serratia symbiotica , Hamilton defensa , Regiella insecticola and Spiroplasma spp. for R. padi , and with the total symbiont density, total bacteria (16S rRNA) and with all aphid-specific bacterial symbionts (except Spiroplasma spp.) for S. avenae . The overall study results corroborate the potential role of the bacterial symbionts of aphids in conferring thermal tolerance to their hosts.
Keywords	wheat aphids ; thermal traits ; critical thermal maxima ; chronic temperature tolerance ; aphid endosymbionts ; bacterial gene abundance ; Science ; Q
Subject code	590
Language	English
Publishing date	2022-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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