B-SPLINE TIGHT FRAMELETS FOR SOLVING INTEGRAL ALGEBRAIC EQUATIONS WITH WEAKLY SINGULAR KERNELS

Taqi A. M. Shatnawi,Wasfi Shatanawi 경남대학교 수학교육과 2022 Nonlinear Functional Analysis and Applications Vol.27 No.2

In this paper, we carried out a new numerical approach for solving integral algebraic equations with weakly singular kernels. The novel method is based on the construction of B-spline tight framelets using the unitary and oblique extension principles. Some numerical examples are given to provide further explanation and validation of our method. The result of this study introduces a new technique for solving weakly singular integral algebraic equation and thus in turn will contribute to providing new insight into approximation solutions for integral algebraic equation (IAE).

Numerical Investigation on Composite Porous Layers in Electroosmotic Flow

Taqi Ahmad Cheema,김경원,곽문규,이춘영,김규만,박철우 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.1 No.3

Applying mechanical pressure on a solid boundary contact using a thin porous layer has been found to reduce the pore size and porosity near the wall region, limiting the flow and mass transport properties. This reduction may affect the overall performance of devices such as the electroosmotic pump that generally uses a porous media with constant porosity in an electric field. Therefore, to improve the performance of such devices, a composite porous layer that uses a combination of different porosity value based on the location in the porous domain, is employed with a higher porosity near the wall region than that in the central region. In this study, a numerical simulation is conducted to investigate the fluid dynamic and mass transport characteristics using a composite porous layer with electroosmotic flow. A comparison of the results with the pressure-driven flow shows the effectiveness of the composite porous layer in compensating for the loss of porosity and in improving device performance. The proposed methodology may also enhance the performance of green energy devices such as fuel cells.

Numerical investigation of hyperelastic wall deformation characteristics in a micro-scale stenotic blood vessel

Taqi Ahmad Cheema,박철우 한국유변학회 2013 Korea-Australia rheology journal Vol.25 No.3

Stenosis is the drastic reduction of blood vessel diameter because of cholesterol accumulation in the vessel wall. In addition to the changes in blood flow characteristics, significant changes occur in the mechanical behavior of a stenotic blood vessel. We conducted a 3-D study of such behavior in micro-scale blood vessels by considering the fluid structure interaction between blood flow and vessel wall structure. The simulation consisted of one-way coupled analysis of blood flow and the resulting structural deformation without a moving mesh. A commercial code based on a finite element method with a hyperelastic material model (Neo-Hookean) of the wall was used to calculate wall deformation. Three different cases of stenosis severity and aspect ratios with and without muscles around the blood vessel were considered. The results showed that the wall deformation in a stenotic channel is directly related to stenosis severity and aspect ratio. The presence of muscles reduces the degree of deformation even in very severe stenosis.

Numerical Investigation on the Effects of the Positional Variation of Porosity in Thin Porous Layers

Taqi Ahmad Cheema,박철우,이춘영,김규만,홍정구,곽문규 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.7

The application of pressure in the assembly of devices containing thin porous layers has shown significant effects with the presenceof a solid boundary contact. During this process, pore diameters of the thin porous layers are reduced. Thus, the porosity in the nearwall region is effectively reduced. The reduced porosity significantly lowers the overall performance of the devices because of thelimited fluid dynamic variables. A new method for the positional variation of porosity is proposed to compensate the fluid dynamicdisadvantages and mass transport characteristics in the industrial devices such as filters, porous electroosmotic pump and fuel cells. In the present study, the novel method introduces a composite porous layer with high porosity in the outer region rather than in thecentral region of the porous media. A three-dimensional numerical simulation is performed to investigate the effects of this positionalvariation of porosity and the performance of the composite porous layer. A reasonable increase in flow rate is found in the wall regionand in the central region, depending on the increment in the porosity in the outer region and on the orientation of the porous layerto the fluid flow.

Effects of Composite Porous Gas-Diffusion Layers on Performance of Proton Exchange Membrane Fuel Cell

Taqi Ahmad Cheema,김규만,이춘영,곽문규,김형범,박철우 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.1 No.4

The gas diffusion layer (GDL) is an important component of proton-exchange membrane fuel cells (PEMFCs) that participate in the interplay of the transport of different species. During the assembly of PEMFCs, mechanical pressure is applied to the solid boundary of bipolar plates to reduce the porosity of the adjacent GDL, especially under land areas. This variation in porosity reduces reactant consumption in the catalyst layer and primarily causes non-uniform current density in PEMFCs. To compensate for the loss of porosity in the GDL, a composite porous diffusion layer was used as a GDL with higher porosity in the under-land areas of the GDL than that in the under-channel areas. A numerical simulation was conducted to investigate the effect of the positional variation of porosity on the performance of the PEMFC. The overall performance of the cell was investigated through a polarization plot, and the local mass transport of the reactant species was evaluated at the two reaction sites. The introduction of the proposed composite porous GDL improved the performance of the PEMFC by enhancing the transport of the reactant species to and from the reaction site.

Characteristics of Blood Vessel Wall Deformation with Porous Wall Conditions in an Aortic Arch

Cheema, Taqi Ahmad,Kim, Gyu Man,Lee, Choon Young,Hong, Jung Goo,Kwak, Moon Kyu,Park, Cheol Woo Sciendo 2014 Applied rheology Vol.24 No.2

<P><B>Abstract</B></P><P>Blood vessels have been modeled as non-porous structures that are permeable to solutes mixed in the blood. However, the use of non-physiological boundary conditions in numerical simulations that assume atmospheric pressure at the outlet does not illustrate the actual structural physics involved. The presence of pores in the wall influences wall deformation characteristics, which may increase the risk of rupture in specific conditions. In addition, the formation of secondary flows in a curved blood vessel may add complications to the structural behavior of the vessel walls. These reservations can be addressed by a fluid structure interaction-based numerical simulation of a three-dimensional aortic arch with increased physiological velocity and pressure waveforms. The curvature radius of the arch was 30 mm with a uniform aorta diameter of 25 mm. A one-way coupling method was used between physics of porous media flow and structural mechanics. A comparison of results with a non-porous model revealed that the approximated porous model was more prone to hypertension and rupture. Similarly, the secondary flows found to be an important indicator for the vascular compliance that forced the outer aortic region to experience the largest deformation. Consequently, it is very important to use actual physiological situations of the blood vessels to reach a diagnostic solution.</P>

Numerical investigation on composite porous layers in electroosmotic flow

Cheema, Taqi Ahmad,Kim, Kyung Won,Kwak, Moon Kyu,Lee, Choon Young,Kim, Gyu Man,Park, Cheol Woo SPRINGER 2014 INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND Vol. No.

FSRP: Fast Service Data Retrieval Protocol For IP-USN

Muhammad Taqi Raza H. M.,Syed Rehan Afzel,Chung Tae-Sun,Seung-wha Yoo,Ki-Hyung Kim 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

IP-Ubiquitous Sensor Network (IP-USN) is a network composed of smart sensor nodes that are small, low power and limited memory devices, connected with the internet over IPv6, and capable of environment sensing, data computing and wireless communication among the sensor nodes. Energy conservation is the major issue in the sensor network paradigm, because lower energy cost increases the overall life time of the sensor network. IP-USN wide range of applications in scientific, medical, commercial, and military domain, stands out service discovery role from all. Sensor nodes need to store some amount of service information due to the fact that timely querying for service data decreases the network performance. So in this paper, we proposed an efficient service data retrieval protocol that stores the information about the services which are more often than not, resulting fast data retrieval possible under low energy costs. We also discussed the performance between SD protocol with and without FSRP implementation.

Recruiting Distant Hybridization for Reshaping Meiotic Recombination

Mohammad Taqi Rabbani,Gyanisha Nayak 한국육종학회 2023 Plant Breeding and Biotechnology Vol.11 No.3

Gene introgression that involves the transfer of favorable allelic diversity for broadening the genetic base of breedingmaterials is a powerful 'toolkit' for creating novel allelic combinations during plant sexual reproduction. It is a key factor playing animportant role in plant breeding schemes by reintroducing genetic variation at selective sweeps or introgression of desirable traitsrequired for the development of new varieties. Meiosis is a specialized cell division not only enables sexually reproducing organismsto reduce their genomic constituent by half, also provides indefinitely novel combinations of allelic diversity by reshuffling the parentalgenetic makeup. Crossing over that takes place during prophase-I facilitates the meiotically exchange of genetic materials betweenhomolog pairs as well as their accurate segregations. It is tightly modulated and many intrinsic factors and extrinsic agents areassociated with regulation of the process, however, the modulation of meiosis is possible. Although, advanced approaches such asCRIPR/Cas and Virus-Induced gene Silencing (VIGS) have opened new horizons for manipulation of meiotic recombination, distanthybridization could effectively influence the frequency and distribution of homologous (HR) and particularly homoeologousrecombination (HeR). In this review, we provide a brief overview of the recent advances in the plant mechanisms for manipulation ofHR and HeR employing distant hybridization.

Effects of composite porous gas-diffusion layers on performance of proton exchange membrane fuel cell

Cheema, Taqi Ahmad,Kim, Gyu Man,Lee, Choon Young,Kwak, Moon Kyu,Kim, Hyoung Bum,Park, Cheol Woo SPRINGER 2014 INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND Vol. No.