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Institution

Ghulam Ishaq Khan Institute of Engineering Sciences and Technology

EducationTopi, Pakistan
About: Ghulam Ishaq Khan Institute of Engineering Sciences and Technology is a education organization based out in Topi, Pakistan. It is known for research contribution in the topics: Quantum efficiency & Diode. The organization has 618 authors who have published 940 publications receiving 10674 citations.


Papers
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Proceedings ArticleDOI
15 Nov 2010
TL;DR: In this article, the authors present statistics of path loss for 60 GHz millimeter wave propagation channel simulations that are performed in the presence of humans in different indoor environments, where the human bodies are considered as randomly distributed cylinders in a room.
Abstract: This paper presents statistics of path loss for 60 GHz millimeter wave propagation channel simulations that are performed in the presence of humans in different indoor environments. A deterministic propagation model is used as an experimental tool to investigate the narrowband characteristics of the channel. The indoor radio propagation channel is modeled by using ray tracing and humans are modeled as perfectly conducting cylinders. The human bodies are considered as randomly distributed cylinders in a room. By varying both the number of persons and room size their effect on the received signal strength i.e. its fading distribution has been studied statistically. For a fixed room size as the number of persons increase, the variance of path loss increases due to more variations in the received signal. The variance decreases as the room size increases for a fixed number of persons. It was found that change in the dimensions of the rooms for a given area caused the statistics of path loss to change.

2 citations

Journal ArticleDOI
TL;DR: In this article, numerical analysis of structural engineering of conventional LED has been presented to enhance the performance of green light-emitting diodes (LEDs), and the proposed structure with composition-graded electron blocking layer as well as thickness-graded last quantum barrier and last quantum well shows improved radiative recombination rate, lower efficiency droop and higher light output power at high current density in comparison to other devices.
Abstract: To enhance the performance of green light-emitting diodes (LEDs), numerical analysis of structural engineering of conventional LED has been presented. Our proposed structure with composition-graded electron blocking layer as well as thickness-graded last quantum barrier and last quantum well shows improved radiative recombination rate, lower efficiency droop and higher light output power at high current density in comparison to other devices. The observed improvements are because of better electron and hole confinement as well as improved hole transportation inside the active region.

2 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed that high reflection surfaces and polarization rotators can be designed using planar stratified metamaterials (MTMs), which are composed of strong chiral, dielectric, double negative, chiral nihility, and single negative MTM slabs.
Abstract: In this paper, it is proposed that high reflection surfaces and polarization rotators can be designed using planar stratified metamaterials (MTMs). For this purpose, structures used in design are composed of strong chiral, dielectric, double negative, chiral nihility, and single negative MTM slabs. To investigate these multilayered structures, reflection and transmission coefficients are analytically computed using transfer matrix method. The expressions depend on frequency, angle of incidence, optical width of slab, and material parameters. The structures are tested for numerical values and then optimized results are presented. For each case, structure is composed of odd number of infinite length slabs. These structures can be used in filters, radomes, and polarization conversion devices.

2 citations

Book ChapterDOI
01 Jan 2011
TL;DR: In this paper, the goodness-of-fit of a continuous distribution for a set of n observations grouped into N equal probability intervals is considered and the chi-square test is shown to be optimal in terms of the Pitman's and the Kalenberg's intermediate asymptotic efficiencies.
Abstract: The problem of testing the goodness-of-fit of a continuous distribution for a set of n observations grouped into N equal probability intervals is considered. It is assumed that N → ∞ as n → ∞. Let η1, …, η N be the numbers of observations in the intervals. We show that within the class of tests based on statistics of the form fη1 + ⋯ + fη N the classical chi-square test is optimal in terms of the Pitman’s and the Kalenberg’s intermediate asymptotic efficiencies but it is much inferior to tests satisfying Cramer condition in terms of the Kalenberg’s strong intermediate and the Bahadur’s exact asymptotic efficiencies. For the chi-square statistic, a probability of large deviation result, likely to be of its own interest, is proved.

2 citations

Proceedings ArticleDOI
07 Jul 1997
TL;DR: In this article, the authors used scatterometry to measure silylated wafers to detect unwanted variations in processing conditions so that corrective responses can be implemented, which is a technique that is rapid, non-destructive and sensitive to changes introduced by the silylation process.
Abstract: The silylation step in the top surface imaging process has been difficult to monitor and characterize for lack of appropriate metrology tools. Utilizing scatterometry to measure silylated wafers, we report successful monitoring of processing effects. Wafers were manufactured under nominally identical processing conditions. Applying scatterometry, we are able to discern location dependent variations within wafers. In addition, wafer to wafer variations are also observe. Both these variations are detrimental to yield. Variations in processing conditions cause modifications and perturbations in the gratings. Different gratings diffract light in a dissimilar manner. Processing conditions and their effects on the wafers are deduced from these measurements using computational analysis. This information is used to detect unwanted variations in processing conditions so that corrective responses can be implemented. This technique is rapid, non-destructive and sensitive to changes introduced by the silylation process.

2 citations


Authors

Showing all 626 results

NameH-indexPapersCitations
Wajid Ali Khan128127279308
Shuichi Miyazaki6945518513
Muhammad Zubair5180610265
Mohammad Islam441929721
Asifullah Khan381925109
Muhammad Waqas323837336
Rana Abdul Shakoor301403244
Noor Muhammad291602656
Abdul Majid282313134
Muhammad Abid273773214
Iftikhar Ahmad261432500
Shaheen Fatima24792287
Ghulam Hussain241271937
Zubair Ahmad241451899
Muhammad Zahir Iqbal231291624
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20235
20229
2021180
2020154
2019100
201863