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Efficient construction of a substitution box based on a Mordell elliptic curve over a finite field

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Frontiers of Information Technology & Electronic Engineering 2019年第10期20卷 1378-1389页

作者： naveed ahmed azam Umar HAYAT Ikram ULLAH Department of Applied Mathematics and Physics Graduate School of InformaticsKyoto UniversityKyoto 606-8501Japan Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan

Elliptic curve cryptography has been used in many security systems due to its small key size and high security compared with other cryptosystems. In many well-known security systems, a substitution box (S-box) is the only non-linear component. Recently, it has been shown that the security of a cryptosystem can be improved using dynamic S-boxes instead of a static S-box. This necessitates the construction of new secure S-boxes. We propose an efficient method to generate S-boxes that are based on a class of Mordell elliptic curves over prime fields and achieved by defining different total orders. The proposed scheme is devel-oped in such a way that for each input it outputs an S-box in linear time and constant space. Due to this property, our method takes less time and space than the existing S-box construction methods over elliptic curves. Computational results show that the pro-posed method is capable of generating cryptographically strong S-boxes with security comparable to some of the existing S-boxes constructed via different mathematical structures.

关键词： Substitution box Finite field Mordell elliptic curve Total order Computational complexity

Eukaryotic cell encystation and cancer cell dormancy:is a greater devil veiled in the details of a lesser evil?

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Cancer Biology & Medicine 2015年第1期12卷 64-67页

作者： Abdul Mannan Baig naveed ahmed Khan Farhat Abbas Department of Biological and Biomedical Sciences Aga Khan University

Cancer cell dormancy is the main cause of cancer recurrence and failure of therapy as dormant cells evade not only the anticancer drugs but also the host immune system. These dormant cells veil themselves from detection by imaging and/or using biomarkers, which imposes an additional problem in targeting such cells. A similar form of hibernation process known as encystation is studied in detail for pathogenic unicellular eukaryotic microorganisms. By examination using microarray gene expression profiles, immunocytochemistry tools, and siRNAs during the process of encystation, understanding the covert features of cancer cell dormancy as proposed could be possible. This knowledge can be extended to dormant cancer cells to uncover the mechanisms that underlie this ghost, yet dangerous state of human cancers. We propose a strategy to induce dormancy and exit this state by application of knowledge gained from the encystation induction and retrieval processes in pathogenic eukaryotic microorganisms. Given that early detection and characterization of dormant malignant tumor cells is important as a general strategy to monitor and prevent the development of overt metastatic disease, this homology may enable the design of therapies that could either awake the dormant cell from dormancy to make it available for therapies or prolong such a phase to make cancer appear as a chronic disease

关键词： Cancer cell dormancy cancer recurrence encystation metastasis

Impacts of forestation on the annual and seasonal water balance of a tropical catchment under climate change

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Forest Ecosystems 2021年第4期8卷 856-871页

作者： Hero Marhaento Martijn J.Booij Noorhadi Rahardjo naveed ahmed Faculty of Forestry Universitas Gadjah MadaYogyakarta 55281Indonesia Water Engineering and Management Group Faculty of Engineering TechnologyUniversity of TwenteP.O.Box 2177500 AE Enschedethe Netherlands Faculty of Geography Universitas Gadjah MadaYogyakarta 55281Indonesia Key Laboratory of Mountain Surface Process and Ecological Regulations Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

Background:This study aims to assess the effects of a forestation program and climate change on the annual and seasonal water balance of the Bogowonto catchment(597 km^(2))in Java,*** catchment study is rare example in Indonesia where forestation has been applied at the catchment ***,since the forestation program has been initiated,evaluations of the program only focus on the planting area targets,while the environmental success e.g.,impacts on the hydrological processes have never been *** study used a calibrated Soil and Water Assessment Tool(SWAT)model to diagnose the isolated and combined effects of forestation and climate change on five water balance components,namely streamflow(Q),evapotranspiration(ET),surface runoff(Q_(s)),lateral flow(Q_(l))and base flow(Q_(b)).Results:The results show that from 2006 to 2019,forest cover has increased from 2.7% to 12.8% of the total area,while in the same period there was an increase in the mean annual and seasonal temperature,rainfall,and *** of SWAT simulations show that changes in the mean annual and seasonal water balance under the forestation only scenario were relatively minor,while changes were more pronounced under the climate change only *** on the combined impacts scenario,it was observed that the effects of a larger forest area on the water balance were smaller than the effects of climate ***:Although we found that forestation program has minor impacts compared to that of climate change on the hydrological processes in the Bogowonto catchment,seasonally,forestation activity has decreased the streamflow and surface runoff during the wet season which may reduce the risk of moderate ***,much attention should be paid to the way how forestation may result in severe drought events during the dry ***,we urge the importance of accounting for the positive and negative effects in future forestation programs.

关键词： Forestation Land use change Climate change SWAT model Water balance Bogowonto catchment

Facile formation of hierarchical magnesium silicate hydrate microspheres as an adsorbent for the textile dyes

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Particuology 2024年第10期93卷 99-110页

作者： Tin Kyawoo naveed Karim Chao Jiang Saeed ahmed Weiliang Tian Huiyu Li Yongjun Feng State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsBeijing University of Chemical TechnologyBeijing100029China Department of Chemistry The University of ChakwalChakwal48800Pakistan College of Chemistry and Chemical Engineering Tarim UniversityAlar843300China

Hierarchical porous magnesium silicate hydrate (MSH) microspheres composed of sheets are successfully developed under facile conditions using a hard template. The role of hexadecyltrimethylammonium bromide (CTAB) on the formation and adsorption behavior was also observed for the methyl orange and methylene blue. The formed MSH possesses a surface area of 453.24 m^(2)/g, an average pore size of 6.38 nm, and a pore volume of 0.75 cm^(3)/g without CTAB. Based on the role of CTAB and the change in the ratio of Mg/Si, the MSH retained its sphere-like structure with a variation in pore parameters. The formed MSH was used as an adsorbent to remove methylene blue and methyl orange. The pseudo-second-order kinetic and Langmuir Isotherm models are well-fitted, with a 256.4 mg/g removal capacity and 84.2 mg/g for methylene blue and methyl orange, respectively. The modified MSH with CTAB played a positive role for the methyl orange and a negative role for the methylene blue regarding removal performance.

关键词： Adsorption Hierarchical microspheres Magnesium silicate Methyl orange Methylene blue Surfacemodification

Analytical approach to study a mathematical model of CD4 ＋ T-cells

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International Journal of Biomathematics 2018年第4期11卷 217-228页

作者： Aqsa Nazir naveed ahmed Umar Khan Syed Tauseef Mohyud-Din Department of Mathematics Faculty of Sciences HITEC University Taxila Cantt Pakistan Department of MathematicsCOMSATS Institute of Information Technology Abbottabad Pakistan Center for Research (CFR) University of Islamabad (UoI) Islamabad Pakistan

Human immunodeficiency virus （HIV） emerged as one of the most serious health issues of the modern era. Till date, it challenges the scientists working in the fields related to its prevention, least spread and eradication. It affects not only the person suffering from it but also the communities and their economies. Mathematical modeling is one of the ways to explore the possibilities of prediction （and control） strategies for contagious deceases. In this paper, we have tried to extend the scope of a currently available prediction model for a continuous time span. For this purpose, an analytical investigation of the system of nonlinear differential equations, governing the HIV infection of CD4 ＋ T-cells, is carried out. A new emerging analytical technique Optimal Variational Iteration Method （OVIM） has been used to obtain an analytical and convergent solution. Analytical solutions are continuous solutions that can be used to predict the phenomena without the involvement of interpolation or extrapolation errors. On the other hand, their use in the derived equations, depending upon solution itself, is far easier than the numerical solutions. We have presented the error analysis and the prediction curves graphically. Moreover, a comparison with traditional Variational Iteration is also provided. It is concluded that the traditional method fails to converge for the updated models which involve the delayed differential equations.

关键词： HIV virus analytical investigation VIM OVIM.

A conformable mathematical model for alcohol consumption in Spain

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International Journal of Biomathematics 2019年第5期12卷 203-219页

作者： Aqsa Nazir naveed ahmed Umar Khan Syed Tauseef Mohyud-Din Pepartment of Mathefnaticst Faculty of HITEC University Taxila CanttPakistan Department of Mathematics and Statistics Hazara University MansehruPakistan

A study on the conformable model of alcohol consumption in Spain has been *** the proposed model,the existence as well as the uniqueness of the solution has been discussed with the help of fixed-point *** analytical technique,Variational Iteration Method (VIM),has been used to obtain the solution to the governing system of differential *** the help of suitable plots,the role of fractional order derivative has been *** decreasing values of fractional order derivative,decrease in the number of non-consumers and non-risk consumers has been *** increasing the value of fractional order derivative,a sharp decrease can be seen in the compartment of *** agreement between the current study and the already existing studies,with ordinary derivatives,has also been pointed out.

关键词： Alcohol consumption nonlinear differential equations initial value problem conformable derivative uniqueness fixed-point postulate VIM

DETECTION OF ELECTROMAGNETIC INCLUSIONS USING TOPOLOGICAL SENSITIVITY

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Journal of Computational Mathematics 2017年第5期35卷 642-671页

作者： Abdul Wahab Tasawar Abbas naveed ahmed Qazi Muhammad Zaigham Zia Bio Imaging and Signal Processing Lab. Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology 305-701 Daejeon Korea Department of Mathematics and Statistics Faculty of Basic and Applied Sciences International Islamic University 44000 Islamabad Pakistan Weierstrass Institute for Applied Analysis and Stochastics Leibniz Institute in Forschungsverbund Berlin e. V. (WIAS) Mohrenstr. 39 10117 Berlin Germany Department of Mathematics COMSATS Institute of Information Technology Islamabad Campus Park Road Chak Shahzad 44000 Islamabad Pakistan

In this article, a topological sensitivity framework for far-field detection of a diamet- rically small electromagnetic inclusion is established. The cases of single and multiple measurements of the electric far-field scattering amplitude at a fixed frequency are tak- en into account. The performance of the algorithm is analyzed theoretically in terms of its resolution and sensitivity for locating an inclusion. The stability of the framework with respect to measurement and medium noises is discussed. Moreover, the quantitative results for signal-to-noise ratio are presented. A few numerical results are presented to illustrate the detection capabilities of the proposed framework with single and multiple measurements.

关键词： Electromagnetic imaging Topological derivative Localization Resolution analysis Stability analysis Medium noise Measurement noise.

Spatiotemporal variation and mechanisms of temperature inversion in the Bay of Bengal and the eastern equatorial Indian Ocean

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Acta Oceanologica Sinica 2022年第4期41卷 23-39页

作者： K M azam Chowdhury Wensheng Jiang Guimei Liu Md Kawser ahmed Shaila Akhter College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China KeyLab of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China Department of Oceanography&International Centre for Ocean Governance(ICOG) University of DhakaDhaka 1000Bangladesh National Marine Environmental Forecasting Center Beijing 100081China

In the northern Bay of Bengal,the existence of intense temperature inversion during winter is a widely accepted ***,occurrences of temperature inversion during other seasons and the spatial distribution within and adjacent to the Bay of Bengal are not well *** this study,a higher resolution spatiotemporal variation of temperature inversion and its mechanisms are examined with mixed layer heat and salt budget analysis utilizing long-term Argo(2004 to 2020)and RAMA(2007 to 2020)profiles data in the Bay of Bengal and eastern equatorial Indian Ocean(EEIO).Temperature inversion exists(17.5%of the total 39293 Argo and 51.6%of the 28894 RAMA profiles)throughout the year in the entire study *** shows strong seasonal variation,with the highest occurrences in winter and the lowest in *** winter inversion in the northern Bay of Bengal,two other regions with frequent temperature inversion are identified in this study for the first time:the northeastern part of the Bay of Bengal and the eastern part of the EEIO during summer and *** processes of temperature inversion for different subregions are revealed in the current *** of heat(mean~25 W/m;)below the haline-stratified shallow mixed layer leads to a relatively warmer subsurface layer along with the simultaneous cooling tendency in mixed layer,which controls more occurrence of temperature inversion in the northern Bay of Bengal throughout the *** lower cooling tendency due to net surface heat loss and higher mixed layer salinity leaves the southern part of the bay less supportive to the formation of temperature inversion than the northern *** the EEIO,slightly cooling tendency in the mixed layer along with the subduction of warm-salty Arabian Sea water beneath the cold-fresher Bay of Bengal water,and downwelling of thermocline creates a favorable environment for forming temperature inversion mainly during summer and *** isothermal layer

关键词： temperature inversion Bay of Bengal Argo and RAMA data intrusion of the Arabian Sea water eastern equatorial Indian Ocean penetrative heat below mixed layer depth

Dynamical Behavior and Sensitivity Analysis of a Delayed Coronavirus Epidemic Model

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Computers, Materials & Continua 2020年第10期65卷 225-241页

作者： Muhammad naveed Dumitru Baleanu Muhammad Rafiq Ali Raza Atif Hassan Soori Nauman ahmed Department of Mathematics Air UniversityIslamabadPakistan Department of Mathematics Cankaya UniversityAnkara06530Turkey Department of Medical Research China Medical University HospitalChina Medical UniversityTaichungTaiwan Institute of Space Sciences Magurele-BucharestRomania Faculty of Engineering University of Central PunjabLahorePakistan Department of Mathematics National College of Business Administration and EconomicsLahorePakistan Department of Mathematics and Statistics The University of LahoreLahorePakistan

Mathematical delay modelling has a significant role in the different disciplines such as behavioural,social,physical,biological engineering,and bio-mathematical *** present work describes mathematical formulation for the transmission mechanism of a novel coronavirus(COVID-19).Due to the unavailability of vaccines for the coronavirus worldwide,delay factors such as social distance,quarantine,travel restrictions,extended holidays,hospitalization,and isolation have contributed to controlling the coronavirus *** have analysed the reproduction number and its sensitivity to ***,R_(covid)>1then this situation will help to eradicate the disease and if,R_(covid)>1 the virus will spread rapidly in the human ***-known theorems such as Routh Hurwitz criteria and Lasalle invariance principle have presented for *** local and global stabilizes for both equilibria of the model have also been ***,we have analysed the effect of delay reason on the reproduction *** the last,some very useful numerical consequences have presented in support of hypothetical analysis.

关键词： Coronavirus(COVID-19) delay mathematical model reproduction number sensitive analysis stability analysis