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Search Results: 1 - 10 of 224348 matches for " Zafar R "
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Brownian motion model of random matrices revisited
Sudhir R. Jain,Zafar Ahmed
Physics , 1998,
Abstract: We present a modified Brownian motion model for random matrices where the eigenvalues (or levels) of a random matrix evolve in "time" in such a way that they never cross each other's path. Also, owing to the exact integrability of the level dynamics, we incorporate long-time recurrences into the random walk problem underlying the Brownian motion. From this model, we derive the Coulomb interaction between the two eigenvalues. We further show that the Coulomb gas analogy fails if the confining potential, $V(E)$ is a transcendental function such that there exist orthogonal polynomials with weighting function, $\exp [-\beta E]$, where $\beta $ is a symmetry parameter.
Number of quantal resonances
Zafar Ahmed,Sudhir R. Jain
Physics , 2003, DOI: 10.1088/0305-4470/37/3/022
Abstract: Employing the concept of time-delay, a relation is found which counts the number of quantal resonances supported by a potential. Several simple and advanced illustrations include a treatment of square-well, Dirac delta barrier, an interesting physical situation from neutron reflectometry, and the Delta resonance appearing in the scattering of \pi meson from proton.
Pseudo-unitary symmetry and the Gaussian pseudo-unitary ensemble of random matrices
Zafar Ahmed,Sudhir R. Jain
Physics , 2002, DOI: 10.1103/PhysRevE.67.045106
Abstract: Employing the currently discussed notion of pseudo-Hermiticity, we define a pseudo-unitary group. Further, we develop a random matrix theory which is invariant under such a group and call this ensemble of pseudo-Hermitian random matrices as the pseudo-unitary ensemble. We obtain exact results for the nearest-neighbour level spacing distribution for (2 X 2) PT-symmetric Hamiltonian matrices which has a novel form, s log (1/s) near zero spacing. This shows a level repulsion in marked distinction with an algebraic form in the Wigner surmise. We believe that this paves way for a description of varied phenomena in two-dimensional statistical mechanics, quantum chromodynamics, and so on.
A pseudo-unitary ensemble of random matrices, PT-symmetry and the Riemann Hypothesis
Zafar Ahmed,Sudhir R. Jain
Physics , 2004,
Abstract: An ensemble of 2 x 2 pseudo-Hermitian random matrices is constructed that possesses real eigenvalues with level-spacing distribution exactly as for the Gaussian Unitary Ensemble found by Wigner. By a re-interpretation of Connes' spectral interpretation of the zeros of the Riemann zeta function, we propose to enlarge the scope of search of the Hamiltonian connected with the celebrated Riemann Hypothesis by suggesting that the Hamiltonian could also be PT-symmetric (or pseudo-Hermitian).
Book Review on Pakistan and the New Nuclear Taboo: Regional Deterrence and the International Arms Control Regime  [PDF]
Zafar Khan
Advances in Historical Studies (AHS) , 2013, DOI: 10.4236/ahs.2013.21001
Abstract: Pakistan has always been the focus of international community, strategists, analysts, and academic scholars on various issues more especially on the nuclear issue since Pakistan has embarked its journey from covert to overt nuclearisation of South Asia. Any work in relation to Pakistan’s nuclear weapons program ranging from its nuclear policy to its nuclear security has gained a great significance in the realm of politics and international studies. Rizwana Abbasi’s maiden volume entitled, Pakistan and the New Nuclear Taboo: Regional Deterrence and the International Arms Control Regime is a welcome contribution that would certainly be embraced by the Pakistani security planners and strategic community in general and the wider international audience in particular. The key aim of this book is that norms, values, and regime still matter despite the presence and influence of hard core realism and neo-realism.
Gender Inequality in Education in Afghanistan: Access and Barriers  [PDF]
Zafar Shayan
Open Journal of Philosophy (OJPP) , 2015, DOI: 10.4236/ojpp.2015.55035
Abstract: As a traditional society, Afghanistan has always been a hotbed of gender inequality in different aspects. Especially, women/girls face various obstacles in education. Despite the efforts to improve the education sector in the last decade, the situation of female education still remains deplorable. There is still a long way to go in improving education, in particular female education. This article aims to examine the unequal access of females and males in primary, secondary and higher education, and presents the main obstacles that prevent women or girls from having access to education. The article is prepared by a desk study using a variety of presently available researches, papers and data related to education, women’s rights and gender inequality from national and international organizations.
Population Attributable Risk of Unintentional Childhood Poisoning in Karachi Pakistan
Bilal Ahmed, Zafar Fatmi, Amna R. Siddiqui
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0026881
Abstract: Background The percentage of unintentional childhood poisoning cases in a given population attributable to specific risk factors (i.e., the population attributable risk) which can be calculated; determination of such risk factors associated with potentially modifiable risk factors, are necessary to focus on the prevention strategies. Methods We calculated PARs, using 120 cases with unintentional poisoning and 360 controls in a hospital based matched case- control study. The risk factors were accessibility to hazardous chemicals and medicines due to unsafe storage, child behavior reported as hyperactive, storage of kerosene and petroleum in soft drink bottles, low socioeconomic class, less education of the mother and the history of previous poisoning. Results The following attributed risks were observed: 12% (95% confidence interval [CI] = 8%–16%) for both chemicals and medicines stored unsafe, 19% (15%–23%) for child reported as hyperactive, 40% (38%–42%) for storage of kerosene and petroleum in soft drink bottles, 48% (42%–54%) for low socioeconomic status, 38% (32%–42%) for no formal mothers education and 5.8% (2%–10%) for history of previous poisoning. 48% of cases for overall study population which could be attributed to at least one of the six risk factors. Among girls, this proportion was 23% and 43% among boys. About half of the unintentional childhood poisoning cases in this Pakistani population could be avoided. Conclusion Exposure to potentially modifiable risk indicators explained about half of the cases of unintentional poisoning among children under five years of age in this Pakistani population, indicating the theoretical scope for prevention of the disease.
Effective Use of ICT and Emerging Cellular Technologies for Health Care: E-Govt Reshaping Governance into Good Governance
F. Zafar,R. Saifullah Hassan,Z. Mahmood
Journal of Economics, Business and Management , 2014, DOI: 10.7763/joebm.2014.v2.131
Abstract: This paper highlights best practices of technological influenced e-government using ICT, emerging mobile and web 2-0 technology for the effective health Care & disease management system. Modern technology has given a whole new dimension to the concept of good governance, thus embarking a strong and effective influence on citizens and cultural trends. Authors have investigated successful case studies, which are taken from existing practice of egovernment health care projects within Pakistan. Pakistan was hit by the epidemic of dengue, affecting over 350,000 people in 2010. Due to the unprecedented scale of epidemic, the basic health infrastructure was not ready to address the issue. However by 2012 a monitoring mechanism was devised as an e-Govt health care activity, to log all field activities related to prevention/eradication of the disease. The project focused mobile reporting using android phones, EDGE services, and Google maps. 650 smart phones users reported 43,000 activities. The information received was extrapolated to bring all stakeholders of anti-dengue campaign on a single platform and DIMS (Dengue Information Management System) was conceived. Features of DIMS include: A central dashboard to view and dispose of complaints on real-time coming in from the Helpline and Hospitals e-CRS (Electronic Complaint Routing System). 2 Vector Surveillance System for tracking and reporting all indoor / outdoor larvaciding activities. 3 A Disease Reporting System to manage the clinical and lab diagnosis records of dengue affected patients. Utilization of this system has resulted in 0 % deaths reported due to dengue in the past 1.5 years. Careful investigation of step by step usage, reporting to DMIS with Android phone and working behavior of ICT infrastructure are elaborated in this research.
Investigation of Iron Complex Formation of Anti-Hypertensive Drug: Methyldopa  [PDF]
Tehmina Fiaz, Nasreen Fatima, S. Zafar Abbas Zaidi, Tanveer Abbas, Mohib R. Kazimi
American Journal of Analytical Chemistry (AJAC) , 2015, DOI: 10.4236/ajac.2015.66053
Abstract: The drug administered for any disease may play an unwanted function in biological system. They may have multiple counter effects, one of which is their interaction to bioactive metals. Iron is most common bio essential metal and is reported to interact with antihypertensive drug methyldopa. In the present study, above said complex is analyzed by UV-Visible spectrophotometry. Formation constant of the complex is calculated by using mole ratio method and single point statistical method which is in the range of 1010, values are also calculated which are independent of pH like formation constant. Absorbance maxima were found to be dependent on pH. At lower pH complex shows two broad bands centered at 430 nm and 730 nm. With the rise in pH later peak shifts toward lower wavelength, so 615 nm is selected for further studies. Molar extinction coefficient of the complex is explored by serial dilution method. At all wavelengths it increases with increase in pH. Mole ratio and slope ratio methods are used for exploring stoichiometry. Metal to ligand combining ratio in the complex is 1:2 at pH 4.0 and pH 4.5 while 1:3 at pH 5.0 and pH 5.5.
LR(K) Parser Construction Using Bottom-up Formal Analysis  [PDF]
Nazir Ahmad Zafar
Journal of Software Engineering and Applications (JSEA) , 2012, DOI: 10.4236/jsea.2012.51004
Abstract: Design and construction of an error-free compiler is a difficult and challenging process. The main functionality of a compiler is to translate a source code to an executable machine code correctly and efficiently. In formal verification of software, semantics of a language has more meanings than the syntax. It means source program verification does not give guarantee the generated code is correct. This is because the compiler may lead to an incorrect target program due to bugs in itself. It means verification of a compiler is much more important than verification of a source program. In this paper, we present a new approach by linking context-free grammar and Z notation to construct LR(K) parser. This has several advantages because correctness of the compiler depends on describing rules that must be written in formal languages. First, we have defined grammar then language derivation procedure is given using right-most derivations. Verification of a given language is done by recursive procedures based on the words. Ambiguity of a language is checked and verified. The specification is analyzed and validated using Z/Eves tool. Formal proofs are presented using powerful techniques of reduction and rewriting available in Z/Eves.
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