safi ullah - Academia.edu (original) (raw)

Papers by safi ullah

Sensors

The Internet of Things (IoT) is a widely used technology in automated network systems across the ... more The Internet of Things (IoT) is a widely used technology in automated network systems across the world. The impact of the IoT on different industries has occurred in recent years. Many IoT nodes collect, store, and process personal data, which is an ideal target for attackers. Several researchers have worked on this problem and have presented many intrusion detection systems (IDSs). The existing system has difficulties in improving performance and identifying subcategories of cyberattacks. This paper proposes a deep-convolutional-neural-network (DCNN)-based IDS. A DCNN consists of two convolutional layers and three fully connected dense layers. The proposed model aims to improve performance and reduce computational power. Experiments were conducted utilizing the IoTID20 dataset. The performance analysis of the proposed model was carried out with several metrics, such as accuracy, precision, recall, and F1-score. A number of optimization techniques were applied to the proposed model ...

Sensors (Basel, Switzerland), 2022

Internet of Vehicles (IoV) is an application of the Internet of Things (IoT) network that connect... more Internet of Vehicles (IoV) is an application of the Internet of Things (IoT) network that connects smart vehicles to the internet, and vehicles with each other. With the emergence of IoV technology, customers have placed great attention on smart vehicles. However, the rapid growth of IoV has also caused many security and privacy challenges that can lead to fatal accidents. To reduce smart vehicle accidents and detect malicious attacks in vehicular networks, several researchers have presented machine learning (ML)-based models for intrusion detection in IoT networks. However, a proficient and real-time faster algorithm is needed to detect malicious attacks in IoV. This article proposes a hybrid deep learning (DL) model for cyber attack detection in IoV. The proposed model is based on long short-term memory (LSTM) and gated recurrent unit (GRU). The performance of the proposed model is analyzed by using two datasets—a combined DDoS dataset that contains CIC DoS, CI-CIDS 2017, and CSE-...

Earth and Planetary Physics, 2021

At PMSE (polar mesosphere summer echoes) altitudes, the bite-out condition contains high dust and... more At PMSE (polar mesosphere summer echoes) altitudes, the bite-out condition contains high dust and low electron density. q In the absence of the bite-out condition, the ion effects on conductivity and permittivity are not significant. q In the presence of the bite-out condition, the ion effects on conductivity and permittivity are significant and cannot be excluded.

Journal of Atmospheric and Solar-Terrestrial Physics, 2021

Abstract Using the EISCAT VHF (224 MHz) radar data, an experimental case of aspect sensitivity an... more Abstract Using the EISCAT VHF (224 MHz) radar data, an experimental case of aspect sensitivity and the characteristics of volume reflectivity of Polar Mesosphere Summer Echoes (PMSE) are presented. The data from the PMSE region during 24–28 June and 1 July 2013, when the beam pointed the off-vertical elevation angles (the largest is 28°), are used. It is found that the distribution curve of the volume reflectivity occurrence rate (OR) at different elevation angles obeys a Gaussian distribution as a whole, but there are some differences at different elevation angles. We investigated the aspect sensitivity parameters (θs) at different elevation angles, and found that θs shows a decrease at the altitude range of 82–84 km. In addition, the aspect sensitivity parameters (θs) of the upper and lower layers were calculated respectively when there is double-layer PMSE. The experimental results showed that in the case of double-layer PMSE, the aspect sensitivity of the lower PMSE layer is stronger than that of the upper PMSE layer. This indicates that the lower PMSE layers are associated with more anisotropic turbulence scattering. It provides new evidence on the dependence of PMSE aspect sensitivity on altitude. And possible explanations of the presented results are discussed.

Earth and Planetary Physics, 2020

Polar mesosphere summer echoes (PMSEs) are very strong radar echoes in the polar mesopause in loc... more Polar mesosphere summer echoes (PMSEs) are very strong radar echoes in the polar mesopause in local summer. Here we present the frequency dependence of the volume reflectivity and the effect of energetic particle precipitation on modulated PMSEs by using PMSEs observations carried out by European Incoherent SCATter (EISCAT) heating equipment simultaneously with very high frequency (VHF) radar and ultra high frequency (UHF) radar on 12 July 2007. According to the experimental observations, the PMSEs occurrence rate at VHF was much higher than that at UHF, and the altitude of the PMSEs maximum observed at VHF was higher than that at UHF. Overlapping regions were observed by VHF radar between high energetic particle precipitation and the PMSEs. In addition, high‐frequency heating had a very limited impact on PMSEs when the UHF electron density was enhanced because of energetic particle precipitation. In addition, an updated qualitative method was used to study the relationship between volume reflectivity and frequency. The volume reflectivity was found to be inversely proportional to the fourth power of radar frequency. The theoretical and experimental results provide a definitive data foundation for further analysis and investigation of the physical mechanism of PMSEs.

Biomedical Sciences, 2020

Genital warts are the most commonly sexually transmitted viral infection of human beings caused b... more Genital warts are the most commonly sexually transmitted viral infection of human beings caused by Human Papillomavirus, infecting both male as well as female sexes. The disease is clinically characterized by the appearance of external warts on the genital organs viz penis, scrotum, vulva, anus and perineal area. The present study was designed for the investigation of chemotherapeutic agents for the successful treatment/removal of lesions of genital warts in terms of recovery of patients and clearance percentage of genital organs from the warts. For this purpose, a total of 12 patients infected with genital warts were selected and randomly distributed into four different groups, each group comprising 03 patients. Group A was treated using locally available wart removal preparation Dewart® (Verrugon, Milk Acid), Group B was treated using Podophyllotoxin 15-25%, procured from chemical suppliers, Group C was treated using locally available Duofilm™ (Salicylic Acid 16.7% w/v, Lactic Acid 16.6% w/v) and Group D served as negative control. The results of the current study revealed that the standard and most effective treatment of the genital warts is found to be Podophyllotoxin @15-25%, which showed 100% recovery of the patients and 100% clearance of their genital areas from the stubborn warts. However, Duofilm™ was also found effective, because all the patients were recovered and 80% warts were cleared off from their genitalia, but after few weeks, the lesions reappeared in the patients treated with Duofilm™. Also the warts did not go off with the local brands of Dewart® nor spontaneously recovered.

Earth, Planets and Space, 2018

Based on experimental observations with EISCAT VHF radar during the summer period, July 8-12, 201... more Based on experimental observations with EISCAT VHF radar during the summer period, July 8-12, 2013, the observations of polar mesosphere summer echoes (PMSE) in the absence of particle precipitation indicate that particle precipitation is not a necessary condition for PMSE to exist. But, particle precipitation still affects PMSE when they both occur simultaneously. So in this paper, the relationship between PMSE and particle precipitation both represented by average electron density, occurring simultaneously for time interval of various lengths (t ≥ 2.56 min), is statistically analyzed using the Spearman rank and Pearson linear correlation coefficients. The new method by comparing the average electron density at altitude of 90 km (proxy of particle precipitation) and PMSE region at altitude of 80-90 km (proxy of PMSE) may compare the two phenomena directly and give some relationship between them. The percentage of events having positive values is dominant, which shows that the electron density variations due to the ionization produced by energetic particle precipitations might have some relationship with PMSE intensity. Moreover, the small percentage of negative correlation coefficient observed might be caused by the very strong precipitation at that time.

International Journal of Nanomedicine, 2019

Background: Infections caused by drug resistant bacteria are a major health concern worldwide and... more Background: Infections caused by drug resistant bacteria are a major health concern worldwide and have prompted scientists to carry out efforts to overcome this challenge. Researchers and pharmaceutical companies are trying to develop new kinds of antimicrobial agents by using different physical and chemical methods to overcome these problems. Materials and methods: In the present study, rifampicin conjugated silver (Rif-Ag) nanoparticles have successfully been synthesized using a chemical method. Characterization of the nanoparticles was performed using a UV-Vis spectrophotometer, FTIR, SEM, TEM, and AFM. Results: The AFM, SEM, and TEM results showed that the average particle size of Rif-Ag nanoparticles was about 15-18±4 nm. The FTIR spectra revealed the conjugation of-NH 2 and-OH functional moiety with silver nanoparticles surface. Considering the penetrating power of rifampicin, the free drug is compared with synthesized nanoparticle for antimicrobial, biofilm inhibition, and eradication potential. Synthesized nanoparticles were found to be significantly active as compared to drug alone. Conclusion: This study has shown greater biofilm inhibitory and eradicating potential against methicillin resistant Staphylococcus aureus and Klebsiella pneumoniae, as evident by crystal violet, MTT staining, and microscopic analysis. So, it will be further modified, and studies for the mechanism of action are needed.

Plasma Science and Technology, 2018

Earth, Planets and Space, 2019

Polar mesospheric summer echoes (PMSE) often show different layers. Artificial electron heating e... more Polar mesospheric summer echoes (PMSE) often show different layers. Artificial electron heating experiments are an important diagnostic tool to investigate the parameters in the PMSE regions. The response of PMSE to high frequency heating in the lower (80-85 km) and upper (85-90 km) PMSE layers is studied by analyzing PMSE observations carried out by the EISCAT VHF radar in July 2007. Different characteristics of modulated PMSE (e.g., PMSE intensity reduction, recovery, overshoot, ratios during the heating-on and heating-off times) are analyzed and compared at different situations such as only in one layer (lower or upper) and in both layers simultaneously without high-energy particle precipitation. Based on statistical results, it is found that in the lower layer all characteristics of modulated PMSE except PMSE recovery are greater than that in the upper layer. Electron temperature enhancement and PMSE modulation index due to ionospheric heating were calculated to show the enhanced electron temperature effect on PMSE. It is found that in both layers usually higher electron temperature enhancement corresponds to higher PMSE modulation index. However, the comparison of statistical results shows that in the lower layer electron temperature enhancement and PMSE modulation index are greater than that in the upper layer. Based on the relation of electron temperature enhancement to the PMSE modulation index, it is concluded that the variability of electron temperature enhancement may be responsible for the variations in different modulated PMSE characteristics between the lower and upper layers.

Advances in Space Research, 2019

This paper is based on the observations of Polar Mesosphere Summer Echoes (PMSE) with the EISCAT ... more This paper is based on the observations of Polar Mesosphere Summer Echoes (PMSE) with the EISCAT VHF 224 MHz radar during the summer month 08-12 July 2013. The effect of high energy particle precipitation on PMSE intensity, particularly during their simultaneous occurrence for longer time interval (longer than or equal to 3-h) has been investigated. The correlation between the two phenomena has been computed using the Spearman rank and Pearson linear correlation coefficient. The variations in high energy particle precipitation reaching down to altitude of 91 km and PMSE intensity in the altitude range of 80-90 km are positively correlated. The electron density irregularity due to ionization caused by precipitating particles might be one of the possible reasons for this positive correlation. Moreover, some other background parameters i.e. K-indices (proxy of high energy particle precipitation) and electron fluxes during the simultaneous occurrence of the two phenomena also support one of the possible reasons given for explanation of the observed positive correlation. The X-rays and proton fluxes have no noticeable effect on PMSE echoes in this study.

IEEE Transactions on Electron Devices, 2017

The performance of electronic switching between multiple backward-wave modes is studied in a desi... more The performance of electronic switching between multiple backward-wave modes is studied in a designed extended interaction oscillator (EIO) based on a ladder circuit with finite number of periods to overcome electronic tuning range limits of EIOs operated in standingwave mode. The dispersion characteristic of the circuit with finite number of periods, which is constructed by a series of discrete modes, is investigated. The mode separation is analyzed and reduced to support continuous switching between multiple different modes by increasing the number of periods as compared with the standing-wave EIO approach. An output circuit is designed to extract the power of backward wave. The electronic switching between nine backward-wave modes has been achieved by changing the beam voltage from 4.1 to 10.5 kV, where the maximum output power over 58 W is obtained at 5.3 kV from the simulation prediction. The EIO can operate over an electronic tuning range of 3.53 GHz from 89.65 to 93.18 GHz in ensuring the output power no less than 20 W. This technique can be extensively applied to increase operating band for extended interaction klystrons (EIKs) and electronic tuning range for EIOs, making them more suitable for many potential applications. Index Terms-Backward-wave mode, electronic switching, electronic tuning range, extended interaction oscillator (EIO), vacuum electronics. I. INTRODUCTION M ILLIMETER wave and Terahertz (THz) vacuum electronic device (VED) sources are of great interest in many potential applications including high data rate communications, high-resolution imaging, airborne, and deep space research [1]. As a kind of high-frequency VED source,

International journal of Engineering Works, 2020

Transportation plays an essential role in our everyday lives. Transportation planners often looki... more Transportation plays an essential role in our everyday lives. Transportation planners often looking for systems that are efficient, reliable, and safe. One of the most significant factors in road accidents and public safety is the behavior of drivers. The Driver Behavior Questionnaire (DBQ) has not been used in Peshawar to find driver behavior. The dream of a secure and effective transportation network seems to exacerbate these conditions. The complete DBQ method is essential to find the effectiveness of the DBQ. The Driver Behavior Questionnaire (DBQ) was split into four separate sections. There were three major categories of driver behavior: mistakes, slips and lapses, violations, and unintentional violations. The respondents had to rate themselves on a scale of 1 to 3, how good they think they are, how healthy they think they are. The report concludes with a list of recommendations on how drivers can improve their behavior. Survey was performed at colleges and public buildings in parking lots. Drivers were questioned directly in the parking lot. 250 questionnaires were filled out in total. Statistical Package for Social Sciences (SPSS) was mainly used for the analysis of the data. Almost 64% of people do not have a driving license. 62% consider the process of getting a license difficult while 29% consider it of no use, and they believe they do not need it. Drivers with no driving license do more speeding than those who have a license. Most of the respondents were of the opinion to have strict enforcement of traffic rules, mandatory training before issuing a driving license.