A hybrid tabu search algorithm for Task Allocation in Mobile Crowd-sensing

Akter, Shathee,Yoon, Seokhoon The Institute of Internet 2020 International Journal of Internet, Broadcasting an Vol.12 No.4

One of the key features of a mobile crowd-sensing (MCS) system is task allocation, which aims to recruit workers efficiently to carry out the tasks. Due to various constraints of the tasks (such as specific sensor requirement and a probabilistic guarantee of task completion) and workers heterogeneity, the task allocation become challenging. This assignment problem becomes more intractable because of the deadline of the tasks and a lot of possible task completion order or moving path of workers since a worker may perform multiple tasks and need to physically visit the tasks venues to complete the tasks. Therefore, in this paper, a hybrid search algorithm for task allocation called HST is proposed to address the problem, which employ a traveling salesman problem heuristic to find the task completion order. HST is developed based on the tabu search algorithm and exploits the premature convergence avoiding concepts from the genetic algorithm and simulated annealing. The experimental results verify that our proposed scheme outperforms the existing methods while satisfying given constraints.

Biological Synthesis of Ginsenoside Rd Using Paenibacillus horti sp. nov. Isolated from Vegetable Garden

Akter, Shahina,Huq, Md. Amdadul Springer-Verlag 2018 Current microbiology Vol.75 No.12

Stability and Performance Investigations of Model Predictive Controlled Active-Front-End (AFE) Rectifiers for Energy Storage Systems

Akter, Md. Parvez,Mekhilef, Saad,Tan, Nadia Mei Lin,Akagi, Hirofumi The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

This paper investigates the stability and performance of model predictive controlled active-front-end (AFE) rectifiers for energy storage systems, which has been increasingly applied in power distribution sectors and in renewable energy sources to ensure an uninterruptable power supply. The model predictive control (MPC) algorithm utilizes the discrete behavior of power converters to determine appropriate switching states by defining a cost function. The stability of the MPC algorithm is analyzed with the discrete z-domain response and the nonlinear simulation model. The results confirms that the control method of the active-front-end (AFE) rectifier is stable, and that is operates with an infinite gain margin and a very fast dynamic response. Moreover, the performance of the MPC controlled AFE rectifier is verified with a 3.0 kW experimental system. This shows that the MPC controlled AFE rectifier operates with a unity power factor, an acceptable THD (4.0 %) level for the input current and a very low DC voltage ripple. Finally, an efficiency comparison is performed between the MPC and the VOC-based PWM controllers for AFE rectifiers. This comparison demonstrates the effectiveness of the MPC controller.

Al<i>_X</i> Ga_1-<i>X</i>N Cladding Effect on Intraband Absorption of InGaN Disk Embedded in GaN Nanowire

Akter, Afroja,Yoo, Geonwook,Kim, Sangin,Baac, Hyoung Won,Heo, Junseok American Scientific Publishers 2017 Journal of Nanoscience and Nanotechnology Vol.17 No.5

<P>The electronic intraband absorption in InGaN nanodisks embedded in GaN nanowires with several kinds of cladding materials and without cladding was theoretically investigated. The cladding layer was 5 nm thick, and AlN, GaN, and Al0.4Ga0.6N were considered. The strain distribution, internal electric field, and intraband absorption in the nanodisks were calculated using the elastic energy minimization method and the single-band Schrodinger equation implemented in Nextnano3. For a plain nanowire without cladding, an inhomogeneous strain in the disk caused a piezoelectric field and deformation potential, yielding band-bending and a higher electron probability density in the periphery of the disk. An InGaN nanodisk embedded in a cladding GaN nanowire exhibited a higher intraband absorption. The case of the GaN cladding was optimal owing to the homogeneous surroundings of the disk.</P>

Food Safety and Health Issues of Cultured Meat

Akter, Mst Khodeza,Kim, Myunghee The Korean Society of Food Service Sanitation 2022 급식외식위생학회지 Vol.3 No.1

The use of cultured meat, also known as in vitro meat, is claimed to be a way of meeting the growing demand for meat worldwide in a safe and disease-free manner, without sacrificing animal and lowering greenhouse gas emissions. However, its economic feasibility is limited by its cost, scale-up complexity, public neophobia and technophobia, and an imperfect knowledge of its impacts on human health. Cultured meat, which is obtained from stem cells using tissue engineering techniques, has been described as a potential alternative to the current meat production systems, which have extensive negative effects. To ensure that a food product is safe for human consumption, it is important to consider all aspects of its life cycle. In this context, the current review analyzes the major elements of the cultured meat life cycle, including the incorrect use of chemicals, such as pesticides or antibiotics, as well as improper processing and storage methods that determine the food safety of cultured meat. The purpose of this review is to determine food safety, health issues, and the potential risks associated with cultured meat production.

Femtomolar detection of cardiac troponin I using a novel label-free and reagent-free dendrimer enhanced impedimetric immunosensor

Akter, Rashida,Jeong, Bongjin,Lee, Yong-Mi,Choi, Jong-Soon,Rahman, Md. Aminur Elsevier 2017 Biosensors & bioelectronics Vol.91 No.-

<P><B>Abstract</B></P> <P>A novel highly sensitive dendrimer coupled impedimetric immunosensor was developed for the label-free and reagent-free detection of cardiac troponin I (TnI) in serum samples. The immunosensor probe was fabricated by covalently attaching carboxylic acid-functionalized third generation (G3) poly (amidoamine) (PAMAM) dendrimer (Den) on the 3, 3′, 5, 5′-tetramethyl benzidine (TMB) modified 6-mercaptohexanoic acid (MHA) self-assembled monolayer (SAM) on a gold (Au) electrode. Monoclonal anti-TnI antibody was then covalently immobilized on the Den and TMB attached MHA SAM modified surface. TMB was used as an internal surface redox couple for generating signal which also allowed to avoid the use of an external one (<I>i.e.</I> ferricyanide couple) in solution during the impedance measurement for monitoring the antibody-antigen binding. On the other hand, Den was used as a signal enhancer by immobilizing more anti-body on the immunosensor probe. The immunosensor probe was characterized using X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance (QCM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. The TnI detection in diluted serum was based on the measurement of charge transfer resistance (<I>R</I> <SUB>ct</SUB>) of the electron transfer process of the surface-attached TMB before and after immunobinding. Under the optimized condition, the proposed immunosensor could detect human TnI in diluted serum samples as low as 11.7 fM with a wide linear dynamic range, good stability, and excellent specificity. The validity of the proposed method was tested in various TnI spiked human undiluted serum samples and was compared with the enzyme-linked immunosorbent assay (ELISA). The results suggested that the proposed immunosensor could be a useful tool for practical applications in clinical diagnosis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Impedance-based cardiac troponin I immunosensor was fabricated. </LI> <LI> Reagent-less and label-free detection was developed using tetramethylbenzidine. </LI> <LI> Enhanced detection was achieved using Dendrimer at the probe. </LI> <LI> Detection limit of troponin I in a diluted serum was as low as 11.7 fM. </LI> </UL> </P>

Chittagong University Campus: Rich in Forest Growing Stock of Valuable Timber Tree Species in Bangladesh

Akter, Salena,Rahman, Md. Siddiqur,Al-Amin, M. Institute of Forest Science 2013 Journal of Forest Science Vol.29 No.2

The campus of Chittagong University in Bangladesh is rich in forest ecosystem. The campus has large area with vast tract of land planted with valuable timber tree species. The present study identifies and discovers the potential growing stock of the plantations in the campus area. This Growing stock was measured in three parameters viz. volume, biomass and organic carbon stock. Study identified thirty three economically valuable forest tree species in the plantations of Chittagong University. Out of three growing stock parameters, volume of timber was found to be low in indigenous tree species in the plantation sites other than exotic species. This might be due to their slow growth rate and low density in the plantation sites. However, biomass and organic carbon stock of trees per hactre area showed that indigenous species gather and sequester more timber and carbon respectively than introduced species. Plantations of Chittagong University campus can acquire $25.51m^3/ha$ volume of economically important tree species, where biomass and organic carbon stock is 222.33 tonne/ha and 107.48 tonne/ha respectively. This result shows a positive impression on the plantation site to be considered as good forest reserve.

Spectral relaxation computation of electroconductive nanofluid convection flow from a moving surface with radiative flux and magnetic induction

Akter Shahina,Ferdows M,Bég Tasveer A,Bég O Anwar,Kadir A,Sun Shuyu 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.4

A theoretical model is developed for steady magnetohydrodynamic viscous flow resulting from a moving semi-infinite flat plate in an electrically conducting nanofluid. Thermal radiation and magnetic induction effects are included in addition to thermal convective boundary conditions. Buongiorno’s two-component nanoscale model is deployed, which features Brownian motion and thermophoresis effects. The governing nonlinear boundary layer equations are converted to nonlinear ordinary differential equations by using suitable similarity transformations. The transformed system of differential equations is solved numerically, employing the spectral relaxation method (SRM) via the MATLAB R2018a software. SRM is a simple iteration scheme that does not require any evaluation of derivatives, perturbation, and linearization for solving a nonlinear system of equations. Effects of embedded parameters such as sheet velocity parameter$\lambda$, magnetic field parameter$\beta$, Prandtl number$Pr$, magnetic Prandtl number$Prm$, thermal radiation parameter$Rd$, Lewis number$Le$, Brownian motion parameter$Nb$, and thermophoresis parameter$Nt$ on velocity, induced magnetic field, temperature, and nanoparticle concentration profiles are investigated. The skin-friction results, local Nusselt number, and Sherwood number are also discussed for various values of governing physical parameters. To show the convergence rate against iteration, residual error analysis has also been performed. The flow is strongly decelerated, and magnetic induction is suppressed with greater magnetic body force parameter, whereas temperature is elevated due to extra work expended as heat in dragging the magnetic nanofluid. Temperatures are also boosted with increment in nanoscale thermophoresis parameter and radiative parameter, whereas they are reduced with higher wall velocity, Brownian motion, and Prandtl numbers. Both hydrodynamic and magnetic boundary layer thicknesses are reduced with greater reciprocal values of the magnetic Prandtl number Prm. Nanoparticle (concentration) boundary layer thickness is boosted with higher values of thermophoresis and Prandtl number, whereas it is diminished with increasing wall velocity, nanoscale Brownian motion parameter, radiative parameter, and Lewis number. The simulations are relevant to electroconductive nanomaterial processing.

Application of sweet and taste modifying genes for development in plants: current status and prospects

Akter, Shahina,Huq, Md. Amdadul,Jung, Yu-Jin,Cho, Yong-Gu,Kang, Kwon-Kyoo The Korean Society of Plant Biotechnology 2016 식물생명공학회지 Vol.43 No.4

Sweet and taste modifying proteins are natural alternatives to synthetic sweeteners and flavor enhancers, and have been used for centuries in different countries. Use of these proteins is limited due to less stability and availability. However, recent advances in biotechnology have enhanced their availability. These include production of sweet and taste modifying proteins in transgenic organisms, and protein engineering to improve their stability. Their increased availability in the food, beverage or medicinal industries as sweeteners and flavor enhancers will reduce the dependence on artificial alternatives. Production of transgenic plants using sweet and taste modifying genes, is an interesting alternative to the extraction of these products from natural source. In this review paper, we briefly describe various sweet and taste modifying proteins (such as thaumatin, monellin, brazzein, curculin and miraculin), their properties, and their application for plant development using biotechnological approaches.

Zooplankton community of Ross Sea, Antarctic Ocean in Austral summer

Akter Masuma,Won-Gyu Park,Hyoung-Sul La 한국수산과학회 양식분과 2020 한국수산과학회 양식분과 학술대회 Vol.2020 No.7