370 research outputs found
A 37 GHz Millimeter-Wave Antenna Array for 5G Communication Terminals
No full textThis work presents, design and specific absorption rate (SAR) analysis of a 37 GHz antenna, for 5th Generation (5G) applications. The proposed antenna comprises of 4-elements of rectangular patch and an even distribution. The radiating element is composed of copper material supported by Rogers RT5880 substrate of thickness, 0.254 mm, dielectric constant (εr), 2.2, and loss tangent, 0.0009. The 4-elements array antenna is compact in size with a dimension of 8 mm × 20 mm in length and width. The radiating patch is excited with a 50 ohms connector i.e., K-type. The antenna resonates in the frequency band of 37 GHz, that covers the 5G applications. The antenna behavior is studied both in free space and in the proximity of the human body. Three models of the human body, i.e., belly, hand, and head (contain skin, fat, muscles, and bone) are considered for on-body simulations. At resonant frequency, the antenna gives a boresight gain of 11.6 dB. The antenna radiates efficiently with a radiated efficiency of more than 90%. Also, it is observed that the antenna detunes to the lowest in the proximity of the human body, but still a good impedance matching is achieved considering the −10 dB criteria. Moreover, SAR is also being presented. The safe limit of 2 W/kg for any 10 g of biological tissue, specified by the European International Electro Technical Commission (IEC) has been considered. The calculated values of SAR for human body models, i.e., belly, hand and head are 1.82, 1.81 and 1.09 W/kg, respectively. The SAR values are less than the international recommendations for the three models. Furthermore, the simulated and measured results of the antenna are in close agreement, which makes it, a potential candidate for the fifth-generation smart phones and other handheld devices
A Subjective Logical Framework-Based Trust Model for Wormhole Attack Detection and Mitigation in Low-Power and Lossy (RPL) IoT-Networks
No full textThe increasing use of wireless communication and IoT devices has raised concerns about security, particularly with regard to attacks on the Routing Protocol for Low-Power and Lossy Networks (RPL), such as the wormhole attack. In this study, the authors have used the trust concept called PCC-RPL (Parental Change Control RPL) over communicating nodes on IoT networks which prevents unsolicited parent changes by utilizing the trust concept. The aim of this study is to make the RPL protocol more secure by using a Subjective Logic Framework-based trust model to detect and mitigate a wormhole attack. The study evaluates the trust-based designed framework known as SLF-RPL (Subjective Logical Framework-Routing Protocol for Low-Power and Lossy Networks) over various key parameters, i.e., low energy consumption, packet loss ratio and attack detection rate. The achieved results were conducted using a Contiki OS-based Cooja Network simulator with 30, 60, and 90 nodes with respect to a 1:10 malicious node ratio and compared with the existing PCC-RPL protocol. The results show that the proposed SLF-RPL framework demonstrates higher efficiency (0.0504 J to 0.0728 J out of 1 J) than PCC-RPL (0.065 J to 0.0963 J out of 1 J) in terms of energy consumption at the node level, a decreased packet loss ratio of 16% at the node level, and an increased attack detection rate at network level from 0.42 to 0.55 in comparison with PCC-RPL
Artificial Intelligence for Intelligent Systems: Fundamentals, Challenges, and Applications
No full text\ua9 2025 selection and editorial matter, Inam Ullah Khan, Mariya Ouaissa, Mariyam Ouaissa, Muhammad Fayaz, and Rehmat Ullah. All rights reserved.The aim of this book is to highlight the most promising lines of research, using new enabling technologies and methods based on AI/ML techniques to solve issues and challenges related to intelligent and computing systems. Intelligent computing easily collects data using smart technological applications like IoT-based wireless networks, digital healthcare, transportation, blockchain, 5.0 industry and deep learning for better decision making. AI enabled networks will be integrated in smart cities\u27 concept for interconnectivity. Wireless networks will play an important role. The digital era of computational intelligence will change the dynamics and lifestyle of human beings. Future networks will be introduced with the help of AI technology to implement cognition in real-world applications. Cyber threats are dangerous to encode information from network. Therefore, AI-Intrusion detection systems need to be designed for identification of unwanted data traffic. This book: Provides a better understanding of artificial intelligence-based applications for future smart cities Presents a detailed understanding of artificial intelligence tools for intelligent technologies Showcases intelligent computing technologies in obtaining optimal solutions using artificial intelligence Discusses energy-efficient routing protocols using artificial intelligence for Flying ad-hoc networks (FANETs) Covers machine learning-based Intrusion detection system (IDS) for smart grid It is primarily written for senior undergraduate, graduate students, and academic researchers in the fields of electrical engineering, electronics and communication engineering, and computer engineering
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Rangeland Development in Dera Ghazi Khan, Pakistan
No full textThe first attempt at scientific management of rangelands ini Dera Ghazi Khan, Pakistan, was made in 1960. However, the efforts failed to yield good results, and the area, being extremely arid, was declared unsuitable for range improvement (GOWP 1970). The senior author surveyed the area and prepared another range management project for the area in 1982. Range improvement techniques were designed keeping in view the local ecological conditions. The results obtained so far are very encouraging. The story of failure and success of range improvements in D. G. Khan is presented here for the benefit of the readers.This material was digitized as part of a cooperative project between the Society for Range Management, the National Agricultural Library, and the University of Arizona Libraries.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202
INFLUENCE OF AGRICULTURE EXTENSION SERVICES AND FARMER’S SOCIO-ECONOMIC CHARACTERISTICS ON ADOPTION OF DATE PALM (Phoenix dactylifera L.) IN DISTRICT DERA ISMAIL KHAN, PAKISTAN
No full textThis study was conducted in the major date producing areas (Dakki, Mian Wada, Mathra Abad, Jhok Ghamy Wali, Habib Abad, Bilot Sharif, Himat, Jhok Moazam, Matwala Shah, Chura and Jhok Malkanri) of the district Dera Ismail Khan, by personal interview method from a sample of 51 respondents selected from these areas for quantitative data collection. Most of the respondents have a secondary and higher secondary level of education (39.2%, 33.3%) respectively. 51% respondents has more than 200 kanals land. It was also found that this category (having more than 200 kanals) have higher secondary level of education. Majority of the respondents have no other source of income (74.5%). The grower’s percentage increased gradually and at present 37.2% respondents were attached with date palm cultivation since last 5-10 years whereas 27% were growing date palm from last 20 years. 84% respondents cultivate the “Dakki” cultivar which is one of the most profitable date cultivar but majority of the respondents (74%) got knowledge about enhanced varieties from their fellow farmers and only 22% respondents were educated by extension workers. 77.3% respondents were facing the problems of insect/pest attack but only 54.9% of the selected respondents apply the plant protection measures. Although, all the farmers were satisfied from their date palm production, still 41.5% were expecting to get help from extension department about insects/pest and rodent control while 17% respondents expect others type of help from extension department (inputs). Key words: Date palm, extension services, socio-economic characters, personal interview
Achieving Energy Saving through Proxying Applications on behalf of Idle Devices
No full textSeveral studies in the past have revealed that network end user devices are left powered up 24/7 even when idle just for the sake of maintaining Internet connectivity. Network devices normally support low power states but are kept inactive due to their inability to maintain network connectivity. The Network Connectivity Proxy (NCP) has recently been proposed as an effective mechanism to impersonate network connectivity on behalf of high power devices and enable them to sleep when idle without losing network presence. The NCP can efficiently proxy basic networking protocol, however, proxying of Internet based applications have no absolute solution due to dynamic and non-predictable nature of the packets they are sending and receiving periodically. This paper proposes an approach for proxying Internet based applications and presents the basic software architectures and capabilities. Further, this paper also practically evaluates the proposed framework and analyzes expected energy savings achievable under-different realistic conditions
Intercomparison and Assessment of Stand-Alone and Wavelet-Coupled Machine Learning Models for Simulating Rainfall-Runoff Process in Four Basins of Pothohar Region, Pakistan
No full textThe science of hydrological modeling has continuously evolved under the influence of rapid advancements in software and hardware technologies. Starting from simple rational formulae for estimating peak discharge and developing into sophisticated univariate predictive models, accurate conversion of rainfall into runoff and the assessment of inherent uncertainty has been a prime focus for researchers. Therefore, alternative data-driven methods have gained widespread attention in hydrology. Moreover, scientists often couple conventional machine learning models with data pre-processing techniques, i.e., wavelet transformation (WT), to enhance modelling accuracy. In this context, this research work attempts to explore the latent linkage between rainfall and runoff in Pothohar region of Pakistan by developing a novel linkage of five streamline techniques of machine learning, including single decision tree (SDT), decision tree forest (DTF), tree boost (TB), multilayer perceptron (MLP), and gene expression modeling (GEP), with a more sophisticated variant of WT, i.e., maximal overlap discrete wavelet transformation (MODWT), for boundary correction of the transformed components of timeseries data. This study also implements these machine learning models in a stand-alone mode for a more comprehensive comparative analysis of performances. Furthermore, the study uses a combined-basin approach that divides Pothohar region into two basins to compensate for the complex topographic division of the study area. The results indicate that MODWT-based DTF outperformed other stand-alone and hybrid models in terms of modeling accuracy. In the first scenario, considering the Bunha-Kahan River basin, MODWT-DTF yielded the highest NSE (0.86) and the lowest RMSE (220.45 mm) and R2 (0.92 at lag order 3 (Lo3)) when transformed with daubechies4 (db4) at level three. While in the Soan-Haro River basin, MODWT-DTF produced the highest accuracy modeling at lag order 4 (Lo4) (NSE = 0.88, RMSE = 21.72 m(3)/s, and R2 = 0.91). The highly accurate performance of 3- and 4-days lagged models reflects the temporal consistency in hydrological response of the study area. The comparison of simple and hybrid model performance indicates up to a 55% increase in modeling accuracy due to data pre-processing with wavelet transformation
Exploring the effect of political risks in large infrastructure projects in politically unstable countries using a probabilistic modelling approach
No full textThis research aims to explore and identify political risks on a large infrastructure project in an exaggerated environment to ascertain whether sufficient objective information can be gathered by project managers to utilise risk modelling techniques. During the study, the author proposes a new definition of political risk; performs a detailed project study of the Neelum Jhelum Hydroelectric Project in Pakistan; implements a probabilistic model using the principle of decomposition and Bayes probabilistic theorem and answers the question: was it possible for project managers to obtain all the relevant objective data to implement a probabilistic model
Synthesis of CZTS kesterite by pH adjustment in order to improve the performance of CZTS thin film for photovoltaic applications
No full text[EN] Quaternary CZTS (Cu2ZnSnS4) kesterite thin layers were successfully made by electrochemical deposition method. CZTS thin layers were deposited on Indium Tin Oxide (ITO) from an aqueous solution. In this work, the effects of pH adjustment under ambient conditions of CZTS thin films were studied. The as grown samples were investigated by numerous existing characterization systems. The X-ray diffraction (XRD) proves the polycrystalline description of the layer. The average crystallite size is varying from 10 nm to 24 nm of the films is dependent on the pH of the solution. All the thin films are in the CZTS kesterite phase attributed to A(1) mode at 334 cm(-1) verified by Raman spectroscopy. The SEM and AFM study show that the pH variation of the so-lution improved the surface morphology and topography of the CZTS thin films which increase several nm in grain size. Moreover, the optical analysis indicates a suitable band gap in the range of 1.5-1.8 eV depending upon the sulfurization temperature. It is found that the pH variation affects both the stability and the performance of the high-quality CZTS absorber layer applications. The CZTS layer with 4.80 pH was annealed at 450 degrees C and 500 degrees C, and at these temperatures the band gap was varied. At the end the band gap variations effect on the performance of CZTS based solar cell is being analyzed by using a simulation tool SCAPS-1D.Author Sha fi Ullah acknowledged the post -doctoral contract supported by the, RRHH, postdoctoral contract (PAID-10-20), and Ministerio de Economia y Competitividad (Grant Number PID2019-107137RB-C21) , Universitat Politècnica de València (UPV) Spain. Author Amal Bouich acknowledged the Post -doctoral contract supported by the, RRHH, Postdoctoral contract the Margarita Salas fi nanced with union European Next Generation EU. This research has been funded by Grant PID2019-107137RB-C21 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe". The author Muhammad Aamir Sha fi acknowledge the Higher Education Commission of Pakistan, International Research Support Initiative Program (IRSIP) , for grant No: 1-8/HEC/HRD/2020/10744 PIN: IRSIP 45 Engg 17.Aamir Shafi, M.; Khan, L.; Ullah, S.; Bouich, A.; Ullah, H.; Mari, B. (2022). Synthesis of CZTS kesterite by pH adjustment in order to improve the performance of CZTS thin film for photovoltaic applications. Superlattices and Microstructures. 164:1-10. https://doi.org/10.1016/j.spmi.2022.107185S11016
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