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.

Validation of Neurotensin Receptor 1 as a Therapeutic Target for Gastric Cancer

Akter, Hafeza,Yoon, Jung Hwan,Yoo, Young Sook,Kang, Min-Jung Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.6

Gastric cancer is the fifth most common type of malignancy worldwide, and the survival rate of patients with advanced-stage gastric cancer is low, even after receiving chemotherapy. Here, we validated neurotensin receptor 1 (NTSR1) as a potential therapeutic target in gastric cancer. We compared NTSR1 expression levels in sixty different gastric cancer-tissue samples and cells, as well as in other cancer cells (lung, breast, pancreatic, and colon), by assessing NTSR1 expression via semi-quantitative real-time reverse transcription polymerase chain reaction, immunocytochemistry and western blot. Following neurotensin (NT) treatment, we analyzed the expression and activity of matrix metalloproteinase-9 (MMP-9) and further determined the effects on cell migration and invasion via wound-healing and transwell assays. Our results revealed that NTSR1 mRNA levels were higher in gastric cancer tissues than non-cancerous tissues. Both of NTSR1 mRNA levels and expression were higher in gastric cancer cell lines relative to levels observed in other cancer-cell lines. Moreover, NT treatment induced MMP-9 expression and activity in all cancer cell lines, which was significantly decreased following treatment with the NTSR1 antagonist SR48692 or small-interfering RNA targeting NTSR1. Furthermore, NT-mediated metastases was confirmed by observing epithelial-mesenchymal transition markers SNAIL and E-cadherin in gastric cancer cells. NT-mediated invasion and migration of gastric cancer cells were reduced by NTSR1 depletion through the Erk signaling. These findings strongly suggested that NTR1 constitutes a potential therapeutic target for the inhibition of gastric cancer invasion and metastasis.

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.

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

A Probabilistic Tensor Factorization approach for Missing Data Inference in Mobile Crowd-Sensing

Akter, Shathee,Yoon, Seokhoon The Institute of Internet 2021 International Journal of Internet, Broadcasting an Vol.13 No.3

Mobile crowd-sensing (MCS) is a promising sensing paradigm that leverages mobile users with smart devices to perform large-scale sensing tasks in order to provide services to specific applications in various domains. However, MCS sensing tasks may not always be successfully completed or timely completed for various reasons, such as accidentally leaving the tasks incomplete by the users, asynchronous transmission, or connection errors. This results in missing sensing data at specific locations and times, which can degrade the performance of the applications and lead to serious casualties. Therefore, in this paper, we propose a missing data inference approach, called missing data approximation with probabilistic tensor factorization (MDI-PTF), to approximate the missing values as closely as possible to the actual values while taking asynchronous data transmission time and different sensing locations of the mobile users into account. The proposed method first normalizes the data to limit the range of the possible values. Next, a probabilistic model of tensor factorization is formulated, and finally, the data are approximated using the gradient descent method. The performance of the proposed algorithm is verified by conducting simulations under various situations using different datasets.

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

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>

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>

The Relationship among Perceptions of Green HRM, Green Work Climate, Employee Green Motivation, and Environmental Commitment: The Case of Bangladesh Textile Industry

Akter Afroza,이현응 중앙대학교 Human Engagement Institute 2023 역량개발학습연구 Vol.18 No.4

As global concerns about environmental degradation and climate change intensify, green human resource management (GHRM) has emerged as a crucial strategic approach for organizations that are recognizing the need to align their human resource practices with sustainable, eco-friendly initiatives. In this study, it is proposed that GHRM affects employees’ environmental commitment by fostering a green work climate and enhancing their green motivation. To gather empirical evidence for this proposition, the researchers collected data from 201 Bangladeshi employees working in the textile industry, and conducted statistical analysis using structural equation modeling (SEM). The findings of the study are as follows: First, perceptions of GHRM had significant positive relationships with both perceived green work climate and employee green motivation. Second, perceived green work climate did not have a significant relationship with employee green motivation controlling for perceptions of GHRM. Third, both perceived green work climate and employee green motivation had positive relationships with environmental commitment. Fourth, both perceived green work climate and employee green motivation had significant mediating effects on the GHRM-environmental commitment relationship. Implications and suggestions are presented based on these findings.

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.