http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A High Throughput On-Demand Routing Protocol for Multirate Ad Hoc Wireless Networks
RAHMAN, Md. Mustafizur,HONG, Choong Seon,LEE, Sungwon The Institute of Electronics, Information and Comm 2010 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.93 No.1
<P>Routing in wireless ad hoc networks is a challenging issue because it dynamically controls the network topology and determines the network performance. Most of the available protocols are based on single-rate radio networks and they use hop-count as the routing metric. There have been some efforts for multirate radios as well that use transmission-time of a packet as the routing metric. However, neither the hop-count nor the transmission-time may be a sufficient criterion for discovering a high-throughput path in a multirate wireless ad hoc network. Hop-count based routing metrics usually select a low-rate bound path whereas the transmission-time based metrics may select a path with a comparatively large number of hops. The trade-off between transmission time and effective transmission range of a data rate can be another key criterion for finding a high-throughput path in such environments. In this paper, we introduce a novel routing metric based on the <I>efficiency of a data rate</I> that balances the required time and covering distance by a transmission and results in increased throughput. Using the new metric, we propose an on-demand routing protocol for multirate wireless environment, dubbed MR-AODV, to discover high-throughput paths in the network. A key feature of MR-AODV is that it controls the data rate in transmitting both the data and control packets. Rate control during the route discovery phase minimizes the route request (RREQ) avalanche. We use simulations to evaluate the performance of the proposed MR-AODV protocol and results reveal significant improvements in end-to-end throughput and minimization of routing overhead.</P>
Rahman, Mohammad Mustafizur,Verdegem, Marc,Wahab, Md Abdul,Hossain, Md Yeamin,Jo, Qtae Blackwell Publishing Ltd 2008 Aquaculture research Vol.39 No.13
<P>Abstract</P><P>Diel rhythmicity of grazing, swimming, resting and social interactions of rohu (<I>Labeo rohita</I>) (weight 66.5–68.3 g) and common carp (<I>Cyprinus carpio</I>) (79.9–82.0 g) were observed in 1 m<SUP>2</SUP> simulated ponds using video images. Fish behaviour was monitored during a full 24-h period, starting at 08:00 hours with a 15-min recording, which was repeated every 3 h. Rohu spent more time grazing during the day than at night. Grazing activity peaked at the beginning and at the end of the day. Grazing and resting of rohu were negatively correlated. Common carp grazed day and night, showing no distinct grazing peak. Considering the grazing time of rohu and common carp, a feeding schedule with two feeding times at 07:30 and 16:30 hours might be appropriate for better food intake and conversion in rohu–common carp polyculture system.</P>
IP-MAC: A Distributed MAC for Spatial Reuse in Wireless Networks
RAHMAN, Md. Mustafizur,HONG, Choong Seon,LEE, Sungwon,LEE, JangYeon,CHO, Jin Woong The Institute of Electronics, Information and Comm 2010 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.93 No.6
<P>The CSMA/CA driven MAC protocols withhold packet transmissions from exposed stations when they detect carrier signal above a certain threshold. This is to avoid collisions at other receiving stations. However, this conservative scheme often exposes many stations unnecessarily, and thus minimizes the utilization of the spatial spectral resource. In this paper, we demonstrate that remote estimation of the status at the active receivers is more effective at avoiding collisions in wireless networks than the carrier sensing. We apply a new concept of the interference range, named as <I>n</I>-tolerant interference range, to guarantee reliable communications in the presence of <I>n</I> (<I>n</I> ≥ 0) concurrent transmissions from outside the range. We design a distributed <I>interference preventive</I> MAC (IP-MAC) using the <I>n</I>-tolerant interference range that enables parallel accesses from the noninterfering stations for an active communication. In IP-MAC, an exposed station goes through an Interference Potentiality Check (IPC) to resolve whether it is potentially interfering or noninterfering to the active communication. During the resolve operation, IPC takes the capture effect at an active receiver into account with interfering signals from a number of possible concurrent transmissions near that receiver. The performance enhancement offered by IP-MAC is studied via simulations in different environments. Results reveal that IP-MAC significantly improves network performance in terms of throughput and delay.</P>
Slotted Transmission: A New MAC Scheme for Reduced Frame Latency in Ad-hoc Networks
( Mustafizur Rahman ),( Choong Seon Hong ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.1
The IEEE 802.11 DCF forces neighboring nodes of an active transmitter to switch into inactive state. This conservative nature brings frame latency at transmitter neighborhood. This work exploits the IEEE 802.11n Frame Aggregation scheme to allow simultaneous transmissions from nodes that are neighbors to each-other. This is accomplished by the synchronization of control and data transmissions in slots of fixed length. Proposed scheme reduces the frame latency and improves aggregated network throughput.
RAHMAN MD MUSTAFIZUR,Rahman Md Mizanor,엄준섭,전종성 한국식물학회 2021 Journal of Plant Biology Vol.64 No.1
Trehalose-6-phosphate phosphatase (TPP) plays a key role in trehalose metabolism in plants. Here, we performed comprehensive in silico analyses and identified 12 OsTPPs (Oryza sativa TPPs) utilizing various bioinformatics tools. Phylogenetic tree, accomplished with OsTPPs and TPPs from 11 monocot and dicot species, was divided mainly into two clades, each clade containing six OsTPPs. Exon–intron distribution was related to phylogenetic clades. All OsTPPs are distributed within nine chromosomes (chr.), except Chr. 1, Chr. 5 and Chr. 11. OsTPPs were found to be stable in nature according to the 3-D structure prediction. Cis-regulatory elements (CREs) were also analyzed using 2 kb upstream of start codon for each gene to predict their biological functions. We categorized all CREs in five distinct groups based on core elements, stress response, cellular development, hormonal regulation, and unknown function, distributed in a range of 3–14 CREs in each group. Interestingly, our expression analysis showed that OsTPPs were more upregulated in response to drought and cold stresses compared to salt stress. Abundance of stress-related CREs found signifies TPPs’ possible role in stress response, which may facilitate to find related transcription factors and unveil complex molecular mechanisms during stress response.
Evaluation of Ultrasonic Vibration Cutting while Machining Inconel 718
Nath, Chandra,Rahman, Mustafizur Korean Society for Precision Engineering 2008 International Journal of Precision Engineering and Vol.9 No.2
Hard and brittle materials, such as Ni- and Ti-based alloys, glass, and ceramics, are very useful in aerospace, marine, electronics, and high-temperature applications because of their extremely versatile mechanical and chemical properties. One Ni-based alloy, Inconel 718, is a precipitation-hardenable material designed with exceptionally high yield strength, ultimate tensile strength, elastic modulus, and corrosion resistance with outstanding weldability and excellent creep-rupture properties at moderately high temperatures. However, conventional machining of this alloy presents a challenge to industry. Ultrasonic vibration cutting (UVC) has recently been used to cut this difficult-to-machine material and obtain a high quality surface finish. This paper describes an experimental study of the UVC parameters for Inconel 718, including the cutting force components, tool wear, chip formation, and surface roughness over a range of cutting conditions. A comparison was also made between conventional turning (CT) and UVC using scanning electron microscopy observations of tool wear. The tool wear measured during UVC at low cutting speeds was lower than CT. UVC resulted in better surface finishes compared to CT under the same cutting conditions. Therefore, UVC performed better than CT at low cutting speeds for all measures compared.