Uncertainty characterization of four machine learning models to gap-fill flux tower observations in the Republic of Korea

Muhammad Sarfraz Khan,Seung-Bae Jeon(전승배),Myeong-Hun Jeong(정명훈) 한국측량학회 2021 한국측량학회 학술대회자료집 Vol.2021 No.11

CONVEXITY PRESERVING PIECEWISE RATIONAL INTERPOLATION FOR PLANAR CURVES

Muhammad Sarfraz 대한수학회 1992 대한수학회보 Vol.29 No.2

Convexity preserving piecewise rational interpolation for planar curves

Sarfraz, Muhammad Korean Mathematical Society 1992 대한수학회보 Vol.29 No.2

This paper uses a piecewise ratonal cubic interpolant to solve the problem of shape preserving interpolation for plane curves; scalar curves are also considered as a special case. The results derived here are actually the extensions of the convexity preserving results of Delbourgo and Gregory [Delbourgo and Gregory'85] who developed a $C^{1}$ shape preserving interpolation scheme for scalar curves using the same piecewise rational function. They derived the ocnstraints, on the shape parameters occuring in the rational function under discussion, to make the interpolant preserve the convex shape of the data. This paper begins with some preliminaries about the rational cubic interpolant. The constraints consistent with convex data, are derived in Sections 3. These constraints are dependent on the tangent vectors. The description of the tangent vectors, which are consistent and dependent on the given data, is made in Section 4. the convexity preserving results are explained with examples in Section 5.

Synergistic effect of incorporating ZIF-302 and graphene oxide to polysulfone to develop highly selective mixed-matrix membranes for carbon dioxide separation from wet post-combustion flue gases

Muhammad Sarfraz,M. Ba-Shammakh 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-

Graphene oxide (GO) nanosheets and zeolitic imidazole frameworks (ZIF-302) were synergisticallyintegrated to glassy polysulfone (PSF) to fabricate mixed-matrix membranes (MMMs) to separate carbondioxide from post-combustion flue gas stream. In order to optimize CO2 separation performance ofcomposite membranes form dry and wet gases, both nanofillers in varying compositions wereincorporated into PSF to prepare MMMs using solution-casting technique. The flexible MMMs renderedhomogeneous dispersion of fillers, improved polymer–filler adhesion, and thermally stable structure. Gas sorption analyses along with dry and wet gas permeation experiments demonstrated improved CO2permeability coupled with high CO2/N2 ideal selectivity of MMMs due to synergistic effect of nanofillers. The hybrid membrane containing 1 wt% GO and 30 wt% ZIF-302 nanofillers showed an optimumseparation performance by providing a CO2 permeability of 13 Barrers with CO2/N2 ideal selectivity of52. The permeation characteristics of hybrid membranes were found to be better than already existingmembranes and were not affected by humid conditions.

The Impact of Entrepreneurial Education on Entrepreneurial Intention During the COVID-19 Pandemic: An Empirical Study from Pakistan

Jan Muhammad SOHU,Ikramuddin JUNEJO,Faiz Muhammad KHUWAJA,Naveed Akhtar QURESHI,Sarfraz Ahmed DAKHAN 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.3

This study aimed to find the mediating impact of entrepreneurial education during COVID-19 on entrepreneurial intention among university students from major cities of Pakistan. Majority of businesses shifted to online from offline mode as a result of COVID-19 pandemic. This created a great opportunity for university students to become entrepreneurs without much investment during COVID-19. Primary data for this study was collected with the help of an adopted questionnaire from previous studies. An online survey was considered appropriate due to the COVID-19 situation in the country. The number of data samples collected from the major cities of Pakistan was 460. The research hypothesis was tested with the help of SmartPLS by using least square structural equation modeling. Findings revealed there is full mediation of entrepreneurial education during COVID-19 between the self-efficacy, subjective norms, and attitude towards entrepreneurship for entrepreneurial intention during COVID-19 among university students. Therefore, the research confirmed the application of the theory of planned behavior among university students in Pakistan with regards to factors such as self-efficacy, subjective norms, attitude towards entrepreneurship and entrepreneurial intention. The present study also concludes that all students regardless of their area of study such as Business and Engineering look forward to become entrepreneurs during COVID-19. The students opting for entrepreneurship had either formal or informal entrepreneurial education during COVID-19.

Stand-alone uncertainty characterization of GLEAM, GLDAS and MOD16 evapotranspiration products using an extended triple collocation approach

Khan, Muhammad Sarfraz,Liaqat, Umar Waqas,Baik, Jongjin,Choi, Minha Elsevier 2018 Agricultural and forest meteorology Vol.252 No.-

<P><B>Abstract</B></P> <P>An optimal use of the global scale actual evapotranspiration (AET) products for various hydro-meteorological applications requires a systematic characterization of their uncertainties. This study presents the first application of an extended triple collocation (TC) approach to provide mutually uncorrelated absolute and relative error structure among three readily available AET (MOD16, GLEAM, and GLDAS) products on the point and spatial scale within the extent of Asia. The physical evaluation results of GLEAM, GLDAS and MOD16 exhibited reasonable accuracy compared to the in-situ AET with mean Index of Agreement >0.71, 0.59 and 0.58, respectively, thereby yielding Root Mean Square Error between ∼4–13 mm/8 day over nine AsiaFlux sites representing forest, rice paddy, and grassland biomes. Theoretical uncertainty assessment of four AET dataset combinations revealed that an average ∼1.5–5.5 mm/8 day random error was contributed from in-situ AET, thereby reducing the accuracy of other datasets. GLEAM performed consistently better with least absolute and relative uncertainties over forest compared with rice paddy and grassland surfaces where GLDAS had almost similar errors as those obtained from GLEAM, while MOD16 showed high uncertainties over all vegetation conditions. Interestingly, all four datasets had large relative uncertainties (>25%) for low vegetation compared to the errors of tall canopies. A spatially merged product generated from the least uncertainties showed better agreement in order of GLDAS > GLEAM > MOD16 over 47%, 42% and 11% of the study area. Overall, the application of extended TC approach on the quality of three AET products is a step forward to develop the merged near real-time accurate AET dataset by processing of theoretical and systematic uncertainties in the current AET algorithms.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Evaluated uncertainty of AET products through an extended triple collocation approach. </LI> <LI> GLEAM and GLDAS showed least absolute uncertainties compared to MOD16 dataset. </LI> <LI> GLEAM revealed low errors in forest but performed similarly as to GLDAS in rice paddy. </LI> <LI> A merged AET map was developed with least uncertainties from three selected products. </LI> </UL> </P>

Assessing the resistance risk to emamectin benzoate in Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae): selection, cross-resistance dynamics and estimates of realized heritability

Afzal Muhammad Babar Shahzad,Riaz Muhammad,Shad Sarfraz Ali,Ijaz Mamuna 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

Emamectin benzoate, a non-systemic, translaminar, and broad spectrum insecticide, is excessively used in cotton. It kills the pest by suppressing the muscle contraction. Phenacoccus solenopsis Tinsley (Hemiptera: Pseudo coccidae) is one of the major sap sucking pests of cotton in many countries and has been shown resistance to various insecticides. In this study, we have continuously selected P. solenopsis with emamectin benzoate in the laboratory from G 3 to G 18 to determine the resistance development and resistance risk to emamectin benzoate and also to evaluate the dynamics of cross-resistance (CR) development with three other insecticides. After continuing selection of P. solenopsis for 16 generations with emamectin benzoate, the emamectin selected strain (Ema-SEL) developed a 280.15-fold resistance when tested at G 19 . Ema-SEL strain showed no CR to abamectin (0.28–1.65-fold), and profenofos (0.12–0.29-fold), but a very low to low CR to cypermethrin (6.02–11.29-fold). Abamectin was negatively cross-resistant with emamectin benzoate in Ema-SEL strain at G 13 , G 15 and G 19 while profenofos also exhibited similar results at G 13 , G 15 , G 17 and G 19 . Realized heritability (h 2 ) of resistance to emamectin benzoate was 0.24 from G 3 to G 19 . The results of projected rate of resistance development showed that if h 2 = 0.24, 0.34, and 0.44 at slope = 1.08, then 2.03, 1.43, and 1.11 generations, respectively are required for tenfold increase in LC 50 at 95 % selection intensity. Results of the present study suggested that P. solenopsis has the ability to develop resistance to emamectin benzoate but it can be managed by the alternate use of other insecticides including abamectin, profenofos and cypermethrin due to lack of/or very low to low CR with these insecticides.

Evaluation of resistance stability and fitness costs in dimethoate-selected strain of Oxycarenus hyalinipennis Costa (Hemiptera: Lygaeidae)

Usama Khan Hafiz Muhammad,Banazeer Ansa,Afzal Muhammad Babar Shahzad,Ali Shad Sarfraz 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Dimethoate belongs to organophosphate (OP) group of insecticides, used worldwide against several economic insect pests. This study was done to evaluate the fitness costs and stability of dimethoate resistance in a previ ously selected strain of dusky cotton bug, Oxycarenus hyalinipennis Costa (Hemiptera: Lygaeidae), a serious sucking pest of cotton. Previously, dimethoate selected (Dimeth-SEL) strain was developed after selecting O. hyalinipennis for six generations in the laboratory. The selected strain expressed resistance ratios (RRs) of 157.76-, and 14.13-fold to dimethoate when compared with Lab Pop, and Unsel Pop, respectively. Data on fitness traits of selected strain reveal that the relative fitness (Rf) of Dimeth-SEL was 0.77 along with significant decrease in nymphal survival, hatchability, net reproductive rate (R0), intrinsic rate of natural increase (r m ), and biotic potential (Bp). The Rf evaluated for Cross 1 and Cross 2 was 1.02 and 0.91, respectively. For resistance stability, Dimeth-SEL (G 6 ) was left unexposed to dimethoate for five generations (G 7 -G 11 ) and the bioassay results at G 11 showed that removal of selected strain from selection pressure resulted in a significant decline in dimethoate resistance. It can be inferred from these results that resistance to dimethoate was developed in O. hyallinipennis at the expense of very high energetic costs and that these costs might also contributed in lowering the resistance levels towards susceptibility after stopping the selection for several generations. These results have practical implications in managing the dimethoate resistance against O. hyallinipennis by implementing the insecticide rotation strategy and also by delaying the dimethoate spray in the field for some generations.

Lipoxygenase Inhibitory Constituents from Indigofera oblongifolia

Sharif, Ahsan,Ahmed, Ejaz,Malik, Abdul,Riaz, Naheed,Afza, Nighat,Nawaz, Sarfraz Ahmad,Arshad, Muhammad,Shah, Muhammad Raza,Chaudhary, Muhammad Iqbal The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.7

Indigin, alkylated xanthene (1) and indigoferic acid (2) have been isolated from the chloroform soluble fraction of Indigofera oblongifolia, along with $\beta$-sitosterol (3) and 3-hydroxybenzoic acid (4), which are reported for the first time from this species. Their structures were determined through spectroscopic techniques. Both the new compounds 1 and 2 showed significant activity against enzyme lipoxygenase, while 2 further showed moderate inhibition against BChE.

Lipoxygenase Inhibitory Constituents from Indigofera oblongifolia

Ahsan Sharif,Ejaz Ahmed,Abdul Malik,Naheed Riaz,Nighat Afza,Sarfraz Ahmad Nawaz,Muhammad Arshad,Muhammad Raza Shah,Muhammad Iqbal Choudhary 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.7

Indigin, alkylated xanthene (1) and indigoferic acid (2) have been isolated from the chloroform soluble fraction of Indigofera oblongifolia, along with β-sitosterol (3) and 3-hydroxybenzoic acid (4), which are reported for the first time from this species. Their structures were determined through spectroscopic techniques. Both the new compounds 1 and 2 showed significant activity against enzyme lipoxygenase, while 2 further showed moderate inhibition against BChE.