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Article ; Online: Fuzzy-Based Quality Adaptation Algorithm for Improving QoE from MPEG-DASH Video

Waqas ur Rahman / Md Delowar Hossain / Eui-Nam Huh

Applied Sciences, Vol 11, Iss 5270, p

2021 Volume 5270

Abstract: Video clients employ HTTP-based adaptive bitrate (ABR) algorithms to optimize users’ quality of experience (QoE). ABR algorithms adopt video quality based on the network conditions during playback. The existing state-of-the-art ABR algorithms ignore the ... ...

Abstract	Video clients employ HTTP-based adaptive bitrate (ABR) algorithms to optimize users’ quality of experience (QoE). ABR algorithms adopt video quality based on the network conditions during playback. The existing state-of-the-art ABR algorithms ignore the fact that video streaming services deploy segment durations differently in different services, and HTTP clients offer distinct buffer sizes. The existing ABR algorithms use fixed control laws and are designed with predefined client/server settings. As a result, adaptation algorithms fail to achieve optimal performance across a variety of video client settings and QoE objectives. We propose a buffer- and segment-aware fuzzy-based ABR algorithm that selects video rates for future video segments based on segment duration and the client’s buffer size in addition to throughput and playback buffer level. We demonstrate that the proposed algorithm guarantees high QoE across various video player settings and video content characteristics. The proposed algorithm efficiently utilizes bandwidth in order to download high-quality video segments and to guarantee high QoE. The results from our experiments reveal that the proposed adaptation algorithm outperforms state-of-the-art algorithms, providing improvements in average video rate, QoE, and bandwidth utilization, respectively, of 5% to 18%, about 13% to 30%, and up to 45%.
Keywords	fuzzy logic ; adaptive bitrate ; DASH ; video streaming ; QoE ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	006
Language	English
Publishing date	2021-06-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Synthesis of 2D transition metal dichalcogenides by chemical vapor deposition with controlled layer number and morphology

Jiawen You / Md Delowar Hossain / Zhengtang Luo

Nano Convergence, Vol 5, Iss 1, Pp 1-

2018 Volume 13

Abstract: Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDs) have stimulated the modern technology due to their unique and tunable electronic, optical, and chemical properties. Therefore, it is very important to study the control parameters for ... ...

Abstract	Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDs) have stimulated the modern technology due to their unique and tunable electronic, optical, and chemical properties. Therefore, it is very important to study the control parameters for material preparation to achieve high quality thin films for modern electronics, as the performance of TMDs-based device largely depends on their layer number, grain size, orientation, and morphology. Among the synthesis methods, chemical vapor deposition (CVD) is an excellent technique, vastly used to grow controlled layer of 2D materials in recent years. In this review, we discuss the different growth routes and mechanisms to synthesize high quality large size TMDs using CVD method. We highlight the recent advances in the controlled growth of mono- and few-layer TMDs materials by varying different growth parameters. Finally, different strategies to control the grain size, boundaries, orientation, morphology and their application for various field of are also thoroughly discussed.
Keywords	Transition metal dichalcogenides (TMDs) ; 2D materials ; Growth mechanisms ; Chemical vapor deposition ; Morphology ; Technology ; T ; Chemical technology ; TP1-1185 ; Biotechnology ; TP248.13-248.65 ; Science ; Q ; Physics ; QC1-999
Subject code	669
Language	English
Publishing date	2018-09-01T00:00:00Z
Publisher	SpringerOpen
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Reaction mechanism and kinetics for CO2 reduction on nickel single atom catalysts from quantum mechanics

Md Delowar Hossain / Yufeng Huang / Ted H. Yu / William A. Goddard III / Zhengtang Luo

Nature Communications, Vol 11, Iss 1, Pp 1-

2020 Volume 14

Abstract: Single atom catalysts (SACs) are promising in electrocatalysis but challenging to characterize. Here, the authors apply a recently developed quantum mechanical grand canonical potential kinetics method to predict reaction mechanisms and rates for CO2 ... ...

Abstract	Single atom catalysts (SACs) are promising in electrocatalysis but challenging to characterize. Here, the authors apply a recently developed quantum mechanical grand canonical potential kinetics method to predict reaction mechanisms and rates for CO2 reduction at different sites of graphene-supported Ni-SACs.
Keywords	Science ; Q
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Reaction mechanism and kinetics for CO2 reduction on nickel single atom catalysts from quantum mechanics

Md Delowar Hossain / Yufeng Huang / Ted H. Yu / William A. Goddard III / Zhengtang Luo

Nature Communications, Vol 11, Iss 1, Pp 1-

2020 Volume 14

Abstract	Single atom catalysts (SACs) are promising in electrocatalysis but challenging to characterize. Here, the authors apply a recently developed quantum mechanical grand canonical potential kinetics method to predict reaction mechanisms and rates for CO2 reduction at different sites of graphene-supported Ni-SACs.
Keywords	Science ; Q
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Synergistic effects of mixing and strain in high entropy spinel oxides for oxygen evolution reaction

Jihyun Baek / Md Delowar Hossain / Pinaki Mukherjee / Junghwa Lee / Kirsten T. Winther / Juyoung Leem / Yue Jiang / William C. Chueh / Michal Bajdich / Xiaolin Zheng

Nature Communications, Vol 14, Iss 1, Pp 1-

2023 Volume 11

Abstract: Abstract Developing stable and efficient electrocatalysts is vital for boosting oxygen evolution reaction (OER) rates in sustainable hydrogen production. High-entropy oxides (HEOs) consist of five or more metal cations, providing opportunities to tune ... ...

Abstract	Abstract Developing stable and efficient electrocatalysts is vital for boosting oxygen evolution reaction (OER) rates in sustainable hydrogen production. High-entropy oxides (HEOs) consist of five or more metal cations, providing opportunities to tune their catalytic properties toward high OER efficiency. This work combines theoretical and experimental studies to scrutinize the OER activity and stability for spinel-type HEOs. Density functional theory confirms that randomly mixed metal sites show thermodynamic stability, with intermediate adsorption energies displaying wider distributions due to mixing-induced equatorial strain in active metal-oxygen bonds. The rapid sol-flame method is employed to synthesize HEO, comprising five 3d-transition metal cations, which exhibits superior OER activity and durability under alkaline conditions, outperforming lower-entropy oxides, even with partial surface oxidations. The study highlights that the enhanced activity of HEO is primarily attributed to the mixing of multiple elements, leading to strain effects near the active site, as well as surface composition and coverage.
Keywords	Science ; Q
Subject code	500
Language	English
Publishing date	2023-09-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Recent Criterion on Stability Enhancement of Perovskite Solar Cells

Md Saif Hasan / Jahangir Alom / Md Asaduzzaman / Mohammad Boshir Ahmed / Md Delowar Hossain / ASM Saem / Jahangir Masud / Jivan Thakare / Md Ashraf Hossain

Processes, Vol 10, Iss 1408, p

2022 Volume 1408

Abstract: Perovskite solar cells (PSCs) have captured the attention of the global energy research community in recent years by showing an exponential augmentation in their performance and stability. The supremacy of the light-harvesting efficiency and wider band ... ...

Abstract	Perovskite solar cells (PSCs) have captured the attention of the global energy research community in recent years by showing an exponential augmentation in their performance and stability. The supremacy of the light-harvesting efficiency and wider band gap of perovskite sensitizers have led to these devices being compared with the most outstanding rival silicon-based solar cells. Nevertheless, there are some issues such as their poor lifetime stability, considerable J–V hysteresis, and the toxicity of the conventional constituent materials which restrict their prevalence in the marketplace. The poor stability of PSCs with regard to humidity, UV radiation, oxygen and heat especially limits their industrial application. This review focuses on the in-depth studies of different direct and indirect parameters of PSC device instability. The mechanism for device degradation for several parameters and the complementary materials showing promising results are systematically analyzed. The main objective of this work is to review the effectual strategies of enhancing the stability of PSCs. Several important factors such as material engineering, novel device structure design, hole-transporting materials (HTMs), electron-transporting materials (ETMs), electrode materials preparation, and encapsulation methods that need to be taken care of in order to improve the stability of PSCs are discussed extensively. Conclusively, this review discusses some opportunities for the commercialization of PSCs with high efficiency and stability.
Keywords	perovskite solar cells ; stability ; moisture ; degradation ; encapsulation ; Chemical technology ; TP1-1185 ; Chemistry ; QD1-999
Subject code	621
Language	English
Publishing date	2022-07-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Efficient Computation Offloading in Multi-Tier Multi-Access Edge Computing Systems

Luan N. T. Huynh / Quoc-Viet Pham / Xuan-Qui Pham / Tri D. T. Nguyen / Md Delowar Hossain / Eui-Nam Huh

Applied Sciences, Vol 10, Iss 1, p

A Particle Swarm Optimization Approach

2019 Volume 203

Abstract: In recent years, multi-access edge computing (MEC) has become a promising technology used in 5G networks based on its ability to offload computational tasks from mobile devices (MDs) to edge servers in order to address MD-specific limitations. Despite ... ...

Abstract	In recent years, multi-access edge computing (MEC) has become a promising technology used in 5G networks based on its ability to offload computational tasks from mobile devices (MDs) to edge servers in order to address MD-specific limitations. Despite considerable research on computation offloading in 5G networks, this activity in multi-tier multi-MEC server systems continues to attract attention. Here, we investigated a two-tier computation-offloading strategy for multi-user multi-MEC servers in heterogeneous networks. For this scenario, we formulated a joint resource-allocation and computation-offloading decision strategy to minimize the total computing overhead of MDs, including completion time and energy consumption. The optimization problem was formulated as a mixed-integer nonlinear program problem of NP-hard complexity. Under complex optimization and various application constraints, we divided the original problem into two subproblems: decisions of resource allocation and computation offloading. We developed an efficient, low-complexity algorithm using particle swarm optimization capable of high-quality solutions and guaranteed convergence, with a high-level heuristic (i.e., meta-heuristic) that performed well at solving a challenging optimization problem. Simulation results indicated that the proposed algorithm significantly reduced the total computing overhead of MDs relative to several baseline methods while guaranteeing to converge to stable solutions.
Keywords	computation offloading ; heterogeneous networks ; multi-access edge computing ; particle swarm optimization ; resource allocation ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Language	English
Publishing date	2019-12-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: FIXED DOSE COMBINATION AND DISEASE MANAGEMENT

Md. Shahid Sarwar / Md. Delowar Hossain

International Research Journal of Pharmacy, Vol 3, Iss 11, Pp 17-

2012 Volume 21

Abstract: Fixed dose combinations (FDCs) are combinations of two or more active drugs in a single dosage form. It is the current hot topic of deliberations in the pharmaceutical industry, drug regulatory agency, and the pharmaceutical trade. Surprisingly, it is ... ...

Abstract	Fixed dose combinations (FDCs) are combinations of two or more active drugs in a single dosage form. It is the current hot topic of deliberations in the pharmaceutical industry, drug regulatory agency, and the pharmaceutical trade. Surprisingly, it is not so among the doctors who prescribe the medicines or the patients who consume. Basically, from one point of view it increases patient compliance, but from other point of view there are chances of consuming medicines, more than what is required. A relook and rationalization may be required in the use of combination product and this is the basis on which this article has been developed.
Keywords	Fixed dose combination ; Essential drugs ; Rational ; Irrational ; Patient compliance ; Drug regulatory bodies. ; Pharmacy and materia medica ; RS1-441 ; Medicine ; R ; DOAJ:Pharmacy and materia medica ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
Language	English
Publishing date	2012-11-01T00:00:00Z
Publisher	International Research Journal of Pharmacy
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The Potentiality of Rice Husk-Derived Activated Carbon

Md Masruck Alam / Md Ashraf Hossain / Md Delowar Hossain / M.A.H. Johir / Jewel Hossen / Md Saifur Rahman / John L. Zhou / A.T.M. Kamrul Hasan / Aneek Krishna Karmakar / Mohammad Boshir Ahmed

Processes, Vol 8, Iss 2, p

From Synthesis to Application

2020 Volume 203

Abstract: Activated carbon (AC) has been extensively utilized as an adsorbent over the past few decades. AC has widespread applications, including the removal of different contaminants from water and wastewater, and it is also being used in capacitors, battery ... ...

Abstract	Activated carbon (AC) has been extensively utilized as an adsorbent over the past few decades. AC has widespread applications, including the removal of different contaminants from water and wastewater, and it is also being used in capacitors, battery electrodes, catalytic supports, and gas storage materials because of its specific characteristics e.g., high surface area with electrical properties. The production of AC from naturally occurring precursors (e.g., coal, biomass, coconut shell, sugarcane bagasse, and so on) is highly interesting in terms of the material applications in chemistry; however, recently much focus has been placed on the use of agricultural wastes (e.g., rice husk) to produce AC. Rice husk (RH) is an abundant as well as cheap material which can be converted into AC for various applications. Various pollutants such as textile dyes, organic contaminants, inorganic anions, pesticides, and heavy metals can be effectively removed by RH-derived AC. In addition, RH-derived AC has been applied in supercapacitors, electrodes for Li-ion batteries, catalytic support, and energy storage, among other uses. Cost-effective synthesis of AC can be an alternative for AC production. Therefore, this review mainly covers different synthetic routes and applications of AC produced from RH precursors. Different environmental, catalytic, and energy applications have been pinpointed. Furthermore, AC regeneration, desorption, and relevant environmental concerns have also been covered. Future scopes for further research and development activities are also discussed. Overall, it was found that RH-derived AC has great potential for different applications which can be further explored at real scales, i.e., for industrial applications in the future.
Keywords	rice husk ; activations ; adsorptions ; dye ; heavy metals ; applications ; Chemical technology ; TP1-1185 ; Chemistry ; QD1-999
Subject code	540
Language	English
Publishing date	2020-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Fuzzy Based Collaborative Task Offloading Scheme in the Densely Deployed Small-Cell Networks with Multi-Access Edge Computing

Md Delowar Hossain / Tangina Sultana / VanDung Nguyen / Waqas ur Rahman / Tri D. T. Nguyen / Luan N. T. Huynh / Eui-Nam Huh

Applied Sciences, Vol 10, Iss 3115, p

2020 Volume 3115

Abstract: Accelerating the development of the 5G network and Internet of Things (IoT) application, multi-access edge computing (MEC) in a small-cell network (SCN) is designed to provide computation-intensive and latency-sensitive applications through task ... ...

Abstract	Accelerating the development of the 5G network and Internet of Things (IoT) application, multi-access edge computing (MEC) in a small-cell network (SCN) is designed to provide computation-intensive and latency-sensitive applications through task offloading. However, without collaboration, the resources of a single MEC server are wasted or sometimes overloaded for different service requests and applications; therefore, it increases the user’s task failure rate and task duration. Meanwhile, the distinct MEC server has faced some challenges to determine where the offloaded task will be processed because the system can hardly predict the demand of end-users in advance. As a result, the quality-of-service (QoS) will be deteriorated because of service interruptions, long execution, and waiting time. To improve the QoS, we propose a novel Fuzzy logic-based collaborative task offloading (FCTO) scheme in MEC-enabled densely deployed small-cell networks. In FCTO, the delay sensitivity of the QoS is considered as the Fuzzy input parameter to make a decision where to offload the task is beneficial. The key is to share computation resources with each other and among MEC servers by using fuzzy-logic approach to select a target MEC server for task offloading. As a result, it can accommodate more computation workload in the MEC system and reduce reliance on the remote cloud. The simulation result of the proposed scheme show that our proposed system provides the best performances in all scenarios with different criteria compared with other baseline algorithms in terms of the average task failure rate, task completion time, and server utilization.
Keywords	multi-access edge computing ; fuzzy logic ; collaborative task offloading ; small-cell network ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	004
Language	English
Publishing date	2020-04-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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