Safi Ullah - Academia.edu (original) (raw)

Papers by Safi Ullah

2019 IEEE 15th International Conference on Control and Automation (ICCA), 2019

We present a framework for the detection of swing and stance phases of gait cycle during walk on ... more We present a framework for the detection of swing and stance phases of gait cycle during walk on a perturbing platform, i.e., a slackline. The framework employs a time varying Kalman filter to reconstruct neural commands from the accelerometer data acquired from slackline perturbations that are generated by the participants. Electromyography (EMG) signals reconstructed from the estimated neural command were compared with surface EMG recordings during slackline walking. For four gait trials, the EMG signals were reconstructed with 92%-95% accuracy. These reconstructed signals were dimensionally reduced using principal component analysis (PCA) and classified using support vector machine (SVM), Decision Tree (DT), Naive Bayes (NB) classifiers. The stance and swing phases were discriminated, the performance of each classifiers was evaluated and classification accuracy was later enhanced with post processing. The DT algorithm outperformed others in detecting the stance and swing phases of gait cycle on slackline with 99.5% accuracy.

Journal of Molecular Structure, 2021

Abstract A series of sulfonated esters of piroxicam 1-19 were synthesized by substitution of “H” ... more Abstract A series of sulfonated esters of piroxicam 1-19 were synthesized by substitution of “H” from hydroxyl “OH” group of piroxicam with different alkyl/aryl sulfonyl chloride by continuous stirring at room temperature. The derivatives were elucidated through various spectroscopic procedures like 1H-NMR, MS, IR, UV and elemental analysis. Piroxicam derivatives were screened for antiglycation activity, in order to analyze the effect of substitution for the management of late diabetic complications. The preliminary results showed that the compounds 2 exhibited potent antiglycation activity far better than the reference (rutin IC50 = 274.5 ± 0.05 µM), while the compounds 5 and 8 were near with IC50 values of 178.9 ± 1.55 µM, 237 ± 2.01 µM, and 256.5 ± 2.56 µM respectively. Moreover a negative effect of electron withdrawing groups was observed over the inhibition potential of different analogues depending upon the number and the positions of the substituents.

Proceedings of the 24th International Symposium on Advancement of Construction Management and Real Estate, 2021

The performance of Chinese contractors is evaluated from the perspective of the characteristics o... more The performance of Chinese contractors is evaluated from the perspective of the characteristics of overseas business of Chinese contractors and its political risks. In this research, further analyses on the fund and pricing model of Chinese Contractors overseas projects were made based on the results of this research projects, as well as their ability to withstand political risks and coping strategies were considered. This research is based on questionnaire data in which 91.1% (328 projects) of the contractors came from large state-owned enterprises, while only 8.9% (42 projects) came from non-state-owned enterprises. This also reflects that China's overseas project contracting is dominated by state-owned enterprises. Among them, 57.6% (213 projects) are contracted by enterprises through the establishment of local subsidiaries, and 42.4% (157 projects) are contracted overseas in the name of parent companies. This survey reflects the general situation of political risks of Chinese contractors in overseas project management. In general, Chinese contractors are facing higher political risks, and they do not attach enough importance to political risks, and their ability to deal with political risks. However, this study is a useful reference for managing the political risks for international contractors when expanding into this emerging market.

Journal of entomology and zoology studies, 2015

Advances in Space Research, 2021

Heating of electrons in PMSE region with powerful high frequency (HF) radio waves is called artif... more Heating of electrons in PMSE region with powerful high frequency (HF) radio waves is called artificial electron heating. This is used as a diagnostic tool to study the interesting radar phenomenon of Polar Mesosphere Summer Echoes (PMSE). Using the PMSE observations of EISCAT UHF (930 MHz) radar from 2003 to 2015, the effect of artificial electron heating on PMSE is studied for the first time in terms of modulated PMSE characteristics. The modulated PMSE characteristics including the PMSE intensity reduction, PMSE intensity recovery, and PMSE overshoot, are analyzed and compared between different height ranges. Our results indicate variability in these characteristics at different height ranges, however, statistics reveal that unlike VHF PMSE these characteristics show a clear difference between the comparatively lower (below 84.0 km) and upper (above 84.0 km) height ranges. It is found that in below 84.0 km height ranges a greater number of heating cycles show PMSE intensity reduct...

All Days, 2017

The importance of improving the drilling performance in an E&P company cannot be under estimated ... more The importance of improving the drilling performance in an E&P company cannot be under estimated as it directly impacts the overall cost of the project. The objective of drilling and well engineering management system is to address the technical and organizational aspects of Drilling operations and deliver the wells in safe and cost effective manner. The different tools that are the vital part of the Drilling and well engineering management system include gates review process for well delivery; section-wise after action review, lesson learned tracking system and non-productive time(NPT) tracking system for continuous improvement from the previous wells. Tools for knowledge and data management and analysis (including technical limits& field specific KPIs) and their input for the upcoming wells is also the part of the system. A cross deliberation, peer review process and auditing system is in place in the process for the compliance check. Notable impacts of the Drilling well engineeri...

Materials, 2021

Marble is currently a commonly used material in the building industry, and environmental degradat... more Marble is currently a commonly used material in the building industry, and environmental degradation is an inevitable consequence of its use. Marble waste occurs during the exploitation of deposits using shooting technologies. The obtained elements most mainly often have an irregular geometry and small dimensions, which excludes their use in the stone industry. There is no systematic way of disposing of these massive mounds of waste, which results in the occurrence of landfills and environmental pollution. To mitigate this problem, an effort was made to incorporate waste marble powder into clay bricks. Different percentage proportions of marble powder were considered as a partial substitute for clay, i.e., 5–30%. A total of 105 samples were prepared in order to assess the performance of the prepared marble clay bricks, i.e., their water absorption, bulk density, apparent porosity, salt resistance, and compressive strength. The obtained bricks were 1.3–19.9% lighter than conventional...

Bulletin of the American Meteorological Society, 2021

Journal of Development and Social Sciences, 2021

Atmospheric Science Letters, 2021

Snow plays an essential role in regulating climate change, the hydrological cycle, and various bi... more Snow plays an essential role in regulating climate change, the hydrological cycle, and various biological processes. Passive microwave snow depth data and gridded data from the Climate Research Unit (CRU_TS4.04) are utilized in this study to investigate spatiotemporal variations of snow depth over the Tibetan Plateau (TP), with special focus on the vertical dimension. The response of snow to elevationdependent warming (EDW) is determined accordingly. High mountains experience more rapid warming than lower elevations. During 1980-2014, the total snow depth over the TP decreased; areas with the most significant decreasing trends are mainly concentrated in the northwestern and southwestern parts of the TP. The plateauwide decrease in snow depth (À0.24 cm/decade) is mainly affected by increasing temperature (0.30 C/decade). The reduction in snow depth trend intensifies as subregional mean elevation increases from 3,332 m (IID2) to 5,074 m (ID1). A stronger snow depth decrease in high-elevation sub-regions generally corresponds to higher warming rates, which demonstrates EDW. The most pronounced correlation between snow depth decrease rate and elevation occurs in the southeastern TP, which covers the largest elevation range on the plateau (from 2,000 to 6,000 m).

ABC Research Alert, 2021

Shazia Omar, a Bangladeshi novelist, depicts the less-known imagery of modern Dhaka in her debut ... more Shazia Omar, a Bangladeshi novelist, depicts the less-known imagery of modern Dhaka in her debut novel “Like a Diamond in the Sky” (2009) where she portrays Bangladesh infected with depression, drug addiction, power-play, corruption and fundamentalism. Deen, the protagonist, is lost in addiction, isolated from his mother and outer world but in love with Maria, aware of the future of Bangladesh and eager to search for the meaning of life. Deen, which literally implies the earthly life in Bangla, is an existentialist who is conscious of himself and the people around him. He is aware of his capacity, limitation, existence and essence. He comments on different orders and institutions that hinder at the path of freedom, and about politicization and islamisation in Bangladesh. Not only Deen but also his widowed mother, his friend AJ, drug peddler Falani, the sergeant of the Police, Deen’s girlfriend Maria- all are conscious of their existence and essence. This novel is about a journey fro...

Journal of Economics, Finance and Administrative Science, 2020

Purpose Financial literacy is a crucial element of financial decision-making, exerting significan... more Purpose Financial literacy is a crucial element of financial decision-making, exerting significant influence on the behaviour of individual investors, while making budgetary, house financing, stock investing and retirement planning decisions. So, the purpose of this research is to determine the relationship between financial literacy and behavioural biases of individual investors in Pakistan. Design/methodology/approach In this research paper, a sample of 300 observations was obtained through questionnaires from individual investors residing in Lahore and invested in Pakistan Stock Exchange. The data obtained, was passed through Cronbach’s Alpha and Exploratory Factor Analysis (EFA). The hypothesis developed for the research was tested by Pearson’s Chi-square and Ordinal Regression Analysis. Findings The hypothesis testing of the research concluded that there is a negative association between financial literacy and behavioural biases of individual investors. So, it means; with an in...

The radar echoes from the polar summer mesopause are observed simultaneously with Digisonde, Dyna... more The radar echoes from the polar summer mesopause are observed simultaneously with Digisonde, Dynasonde, and European Incoherent Scatter Scientific Association (EISCAT) very-high-frequency (VHF) rad...

Journal of Management Info, 2016

Migration is a constant phenomenon in human evolution and had played a vital role in human affair... more Migration is a constant phenomenon in human evolution and had played a vital role in human affairs throughout the ages while the modern world that observe the â€˜age of migrationâ€™ has no exception. Increasing international migratory flow during the last four decades have been the most visible manifestations of the globalization process accompanied by designation of the normative and institutional framework for global governance. This paper examines the relationship between migration and remittances sent by migrants with the educational outcome of left behind children. In this regard, the study has been carried out at Union Council Level in District Dir Lower Khyber Pakhtunkhwa Pakistan. The primary data has obtained from a sample of 99 migrants' families through interview schedule utilizing purposive sampling technique. The collected information has classified and analyzed through computer-based program (SPSS) and the given hypotheses have tested through chi-squire test. The r...

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.

Atmospheric Research, 2018

Changes in precipitation have been widely considered as a critical indicator of climate change. T... more Changes in precipitation have been widely considered as a critical indicator of climate change. This is of prime importance to assess the strength and magnitude of these changes on regional and local scale. To document the observed changes in precipitation over China-Pakistan Economic Corridor (CPEC), the current study was conducted with monthly precipitation data from 53 meteorological stations across the CPEC. The non-parametric Mann-Kendall (MK), Sen's Slope (SS) estimator, and Sequential Mann-Kendall (SQMK) tests were used to assess the trends in precipitation data during 1980 to 2016. The results indicated that winter and post-monsoon precipitation were decreased at the rates of −0.26 and −0.02 mm per year, respectively. Monsoon, pre-monsoon and annual precipitation increased at the rates of 0.14, 0.13, and 0.02 mm per year, respectively. The spatial distribution of trends for seasonal and annual precipitation over different sub-climatic regions indicated that the trend is dynamic and varies from station to station. The station with SS and MK tests for the winter precipitation data showed an increasing (decreasing) trends at 14 (39) stations and only 1 (7) are significant at 0.05 level, respectively. The pre-monsoon, monsoon, post-monsoon, and annual precipitation indicated a positive (negative) trends over 40 (13), 31 (22), and 35 (18), 28 (25) stations with 3 (1), 5 (2), 2, 6 (7) significant stations at significance level of 0.05, respectively. The maximum positive and negative trends were detected at Parachinar (1.82 mm/year) and Dir (−1.86 mm/year) stations in pre-monsoon and winter precipitation, respectively. The mutations in temporal trends of seasonal and annual precipitation are very complex and dynamic during the study period. In winter, the rapid downward shifts were observed in 1984 and 1995. The mutations in premonsoon precipitation occurred after 1996s with a rapid upward/downward shift in 1997/2000. The monsoon precipitation shows a rapid decreasing shift since 1989 and an abrupt upward change in 2011. In post-monsoon precipitation, the rapid downward and upward changes were detected in 1989 and 1999, respectively. The mutations in annual precipitation were found in the first decade of the study period with a steep increase in 1982 and abrupt decrease in 1986. With respect to elevation dependency, the trend of long-term precipitation fluctuates and show a significant increasing trend in elevation zones of ≤500 m and ≥ 1500 m, while the trend decreases in 500-1000 m and 1000-1500 m elevation zones. Moreover, the winter, monsoon and annual precipitation shows negative correlation with elevation, while the pre-monsoon and post-monsoon precipitation show positive correlation with elevation. The findings of this study will help to address the problems of climate change and hydro-meteorological disasters in the regions. Further studies should focus on the climatic drivers of these changes in the regions.

International Journal of Climatology, 1996

Changes in maximum and minimum temperature (T max and T min) are analysed to assess the regional ... more Changes in maximum and minimum temperature (T max and T min) are analysed to assess the regional extent of global warming in Xinjiang autonomous region, China, for the period of 1961-2015. Two nonlinear, non-stationary signal-processing methods-the Bernaola-Galván algorithm and the ensemble empirical mode decomposition method-are applied on daily time series of observations from 53 meteorological stations. Statistically significant abrupt change points are identified in 1996 in both annual T max and T min time series averaged for the whole province, while another one is identified in 1976 in the annual T min time series only. At local scale, most stations experience one abrupt change point in annual T max in the 1990s, but two or three change points in annual T min , mainly in the 1980s and 1990s. After the abrupt change points, the frequency and probability density of T max in summer and T min in winter are skewed towards the hotter part of the probability distribution. It is found that the hot temperature extremes in summer occur concurrently with El Niño events. Further results suggest that anomalies in geopotential height at 500 hPa can be associated with the hottest and coldest months. The key regions of the anomalies are over the east of the Ural Mountains and the North Atlantic, while the geopotential height anomalies over Greenland and the east of the Ural Mountains are closely related to the hot and cold spells. KEY WORDS extreme temperature; nonlinear trend; change point; atmospheric circulation; Xinjiang autonomous region

Lipids in Health and Disease, 2016

Background: Hyperlipidemia, a major pathological condition associated with disrupted lipid levels... more Background: Hyperlipidemia, a major pathological condition associated with disrupted lipid levels and physiological redox homeostasis. The excessive release of reactive oxygen species (ROS) leads to enhanced lipid peroxidation, aggravated atherosclerosis and oxidative stress. Integration of natural antioxidant blends in alone or with conventional treatments can alleviate these issues synergistically contributing least side effects. Published literature reported the efficacy of natural antioxidants as individual and in combinations in various conditions but less data is available on their evaluation in low dose ratio blends particularly in hypercholesterolemic diet. Methods: Antihyperlipidemic effects of selected natural antioxidants; the phenolic oligomeric proanthocyanidins (OPC) and pterostilbene (PT) with niacin (NA) were investigated in current study. Their effects on lipid profile, lipid peroxidation and their aptitude to establish redox state between oxidants and antioxidants in body were evaluated in high cholesterol diet fed animal model. Male albino rabbits (n = 6) weighing 1.2-1.6 kg, supplemented with high cholesterol diet (400 mg/kg) for 12 weeks were used in the experiment. Antioxidants were administered individual high (100 mg/kg) and in low dose combinations (total dose = 100 mg/kg). Student's t test and one way analysis of variance (ANOVA) followed by Dunnet's test were used as statistical tools for evaluation. Results: The results showed synergistic effects of low dose antioxidant blends. Therapies retarded elevation in blood lipid levels, lipid peroxidation and blood antioxidant depletion and consequently contributed in reestablishing redox homeostasis. The LDL/HDL ratio and atherogenic index were suppressed significantly in blend therapies with maximum effects of 59.3 and 25 % (p >0.001) observed in 50:30:20 ratios of OPC, NA and PT, compared to individual therapies 37 and 18 % max respectively. Moreover the results were also in close proximity with the statin therapy (52.66, 26.28 %). Conclusion: This study provides an evidence for natural antioxidants blends superiority over individual therapy in chronic diseases like hyperlipidemia. Such therapies in human equivalent doses can help in mitigating chronic illnesses in general populations.