144 research outputs found
Estimating Passenger Car Equivalent Factors for Heterogeneous Traffic Using Occupancy-Density Linear Regression Model
No full textA variety of methods have been proposed in the existing literature for the estimation of passenger car equivalent (PCE) factors. These methods are based on the comparison of selected attributes of different vehicles. This research, for the first time, utilizes the basic notion of the linear relationship between road area occupancy and density for the estimation of PCE factors for different vehicle types in heterogeneous traffic. Aerial photographs obtained from an unmanned aerial vehicle (UAV) were analyzed to estimate the road area occupancy and the number of vehicles classified in seven selected groups. A linear least-squares regression model was developed between road area occupancy and classified vehicle count. The coefficients of the occupancy-density linear regression model were used to estimate PCE and motorcycle equivalent (MCE) factors. The comparison of the estimated set of PCE values with the values reported in the literature shows that PCE factors estimated using the proposed method are reasonable and produce a better occupancy-density relationship than the other studies. In comparison with the existing methods that rely on lane-based measurements, the proposed method is well suited for traffic with weak/no lane discipline, as it considers the entire road width and the dynamics of lateral movement of different types of vehicles. The proposed method does not need extensive traffic data of speeds, headways, flow rates, and so forth, and is applicable on aerial photographs obtained from other sources, such as satellites.Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported with funding from Exascale Open Data Analytics Lab, National Center for Big Data and Cloud Computing (NCBC) and the Higher Education Commission of Pakistan.
Acknowledgments
The authors are thankful to research students Syed Hassan Ali, Haseeb Ahmed, Zohaib Ahmed, Aqib Abbasi, Asad Rehan, Mirza Ali Haider, Syed Abbas Hasan Zaidi, and Omema for their help in this research
Extended delivery time analysis of opportunistic secondary packet transmission over multiple primary channels
No full textCognitive radio (CR) is one of the most prominent technique to deal with the
radio spectrum scarcity problem. CR systems can improve radio spectrum utilization
by opportunistically accessing the underutilized spectrum resource of the licensed
users. In interweave implementation, the secondary user (SU) has to wait and locate
spectrum holes before its transmission. Therefore, the extended delivery time (EDT)
for the secondary user consist of both wait slots and transmission slots. We study
the EDT analysis of fixed size secondary packet transmission over multiple primary
channel. In particular, we introduce a birth-death based approach to model the
cognitive transmission of the secondary user over multiple primary channels. We use
this approach to derive the exact probability density function and probability mass
function of EDT of the secondary transmission for both continuous and periodic
sensing cases. We also present selected numerical and simulation results to verify our
analytical approach and to illustrate the mathematical formulation.Graduat
Uranium contamination and its bioremediation strategies in soil-plant system
No full textUranium in its natural state is composed of three distinct isotopes: 238, 235, and 234U. This heavy metal has a substantial level of chemical toxicity for biota. It transports radioactivity from the earth into the indoor environment, raising the risk of lung cancer. Its uptake by plants can result in cellular damage and disruption of cellular homeostasis and its regulation. The pH of the environment and the presence of complex ligands are two factors that affect the chemical speciation of uranium in the environment. This chemical speciation determines the destiny, transportation, bioavailability, and dangerous potential of uranium. Both bioavailability and toxicity are extremely sensitive to how an individual is exposed to them. In this chapter, we will focus on and review various sources of uranium as well as its speciation, absorption, toxic effects, and biological remediation techniques in soil-plant systems.No Full Tex
Integrative Evaluation of the Ecological Hazards by Microplastics and Heavy Metals in Wetland Ecosystem
No full textThis study was performed to evaluate the impact of microplastics and heavy metals (Pb, Cd, Cr, Cu, Zn, Ni) on sediments, water, aquatic plants (Pistia stratiotes, Alternanthera philoxeroides, and Ipomoea carnea), and fish (Labeo rohita) samples collected from five different sites in the Bajwat wetlands in Sialkot, Pakistan. The concentrations of Pb, Cd, and Cr were above the permissible limits devised by WHO in all the ecosystem components (i.e. sediments, water, plants, and fish) at all sites. The maximum amount of microplastic particles (2317 microplastic particles per kg of sediments) was recorded at Site 1. The filaments were the most commonly found type of microplastics. Plants and fish samples also showed considerable concentration of metals. The multivariate statistical analysis revealed anthropogenic sources of elevated concentrations of metal elements which could cause adverse biological effects in the ecosystem.No Full Tex
The drivers and barriers to customer value creation: Issues and prespectives in the marble sector SMEs of North-West Frontier Province, Pakistan
No full textThe concept of value and, more specifically, customer value is of increasing interest to both academics and practitioners. Many see it as the next source of competitive advantage. Like other regions of the country, the North-West Frontier Province of Pakistan has a presence of SMEs in many sectors. A major one amongst these is the marble sector; characterized by two sub-sectors, marble mining and marble processing. A review of various studies in the marble sector reveals that about 70 percent of marble reserves in Pakistan are being wasted due to poor mining and processing techniques. The situation is further aggravated by a lack of sound marketing strategies that are focused on value creation that enable these SMEs to enhance competitiveness and achieve greater profitability especially in the international markets. This paper, which is part of the preliminary work for PhD research being carried out by the author at the University of Southampton, UK, tries to examine some of the issues and perspectives regarding customer value creation and relates these concepts to the marble sector of N WF.P. The literature reviewed for this purpose lays emphasis on the concept of value from the dimension of employees and processes. It also highlights some of the drivers and barriers to value creation. By identifying some of the issues and perspectives to customer value creation, this paper would be a first step towards enhancing the competitiveness of Pakistan\u27s marble industry especially in the international market
Evaluating the influence of novel charge transport materials on the photovoltaic properties of MASnI3 solar cells through SCAPS-1D modelling
No full textIn recent decades, substantial advancements have been made in photovoltaic technologies, leading to impressive power conversion efficiencies (PCE) exceeding 25% in perovskite solar cells (PSCs). Tin-based perovskite materials, characterized by their low band gap (1.3 eV), exceptional optical absorption and high carrier mobility, have emerged as promising absorber layers in PSCs. Achieving high performance and stability in PSCs critically depends on the careful selection of suitable charge transport layers (CTLs). This research investigates the effects of five copper-based hole transport materials and two carbon-based electron transport materials in combination with methyl ammonium tin iodide (MASnI3) through numerical modelling in SCAPS-1D. The carbon-based CTLs exhibit excellent thermal conductivity and mechanical strength, while the copper-based CTLs demonstrate high electrical conductivity. The study comprehensively analyses the influence of these CTLs on PSC performance, including band alignment, quantum efficiency, thickness, doping concentration, defects and thermal stability. Furthermore, a comparative analysis is conducted on PSC structures employing both p-i-n and n-i-p configurations. The highest-performing PSCs are observed in the inverted structures of CuSCN/MASnI3/C60 and CuAlO2/MASnI3/C60, achieving PCE of 23.48% and 25.18%, respectively. Notably, the planar structures of Cu2O/MASnI3/C60 and CuSbS2/MASnI3/C60 also exhibit substantial PCE, reaching 20.67% and 20.70%, respectively
AN OVERVIEW OF THE INTERACTIVE LEARNING MANAGEMENT SYSTEM OF JAZAN UNIVERSITY, SAUDI ARABIA
No full textThe effective utilisation of technology provides a more collaborative environment to improve the traditional distance learning. Moreover, it has invigorated a new era of discussion from a range of participants including online learners, learning sources, and eLearning managers. The Learning Management System (LMS) is defined as a hub for handling the overall learning framework in Distance/eLearning education. The system is not only capable of covering the Learning process to the Learners but also acts as a bridge between Learners, Instructors, and learning resources. This study describes the key characteristics and functions of the newly deployed LMS at Jazan University called JUMP (Jazan University Multi-Platforms) with an overview of the previous system, JUSUR, which is an Arabic word, meaning Bridges. The emphasis of deploying JUMP as a new LMS by supplanting the former system is to establish a unified eLearning platform for Jazan
System Biology of Metal Tolerance in Plants: An Integrated View of Genomics, Transcriptomics, Metabolomics, and Phenomics
No full textTowards Secure Fog Computing: A Survey on Trust Management, Privacy, Authentication, Threats and Access Control
Get PDFFog computing is an emerging computing paradigm that has come into consideration for the deployment of Internet of Things (IoT) applications amongst researchers and technology industries over the last few years. Fog is highly distributed and consists of a wide number of autonomous end devices, which contribute to the processing. However, the variety of devices offered across different users are not audited. Hence, the security of Fog devices is a major concern that should come into consideration. Therefore, to provide the necessary security for Fog devices, there is a need to understand what the security concerns are with regards to Fog. All aspects of Fog security, which have not been covered by other literature works, need to be identified and aggregated. On the other hand, privacy preservation for user’s data in Fog devices and application data processed in Fog devices is another concern. To provide the appropriate level of trust and privacy, there is a need to focus on authentication, threats and access control mechanisms as well as privacy protection techniques in Fog computing. In this paper, a survey along with a taxonomy is proposed, which presents an overview of existing security concerns in the context of the Fog computing paradigm. Moreover, the Blockchain-based solutions towards a secure Fog computing environment is presented and various research challenges and directions for future research are discussed
Charcot–Marie–Tooth Disease
Get PDFCharcot–Marie–Tooth (CMT) disease is the most common hereditary polyneuropathy and is classically associated with an insidious onset of distal predominant motor and sensory loss, muscle wasting, and pes cavus.The disease illustrates a multitude of genetic principles, including diverse mutational mechanisms from point mutations to copy number variation (CNV), allelic heterogeneity, age-dependent penetrance and variable expressivity.1 Clinical diagnosis is based on family history and characteristic findings on physical examination, EMG/NCV testing, and occasionally sural nerve biopsy. Molecular genetic testing is possible for some types of CMT.
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