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排序方式: 共有390条查询结果,搜索用时 31 毫秒
51.
52.
Sriram Devanathan Derrick K. Rollins Stephen B. Vardeman 《Computers & Chemical Engineering》2000,24(12):460-2764
This work presents a technique that can completely and accurately identify measurement bias in cases where it is not possible to use the method of Rollins and Davis (1992, 1993) and where the method of Narasimhan and Mah (1987) fail to perform accurately. This technique makes use of information contained in the relationship between individual measurements and the corresponding nodal imbalance. The performance of this method is demonstrated on a problem from the literature that has been difficult for other methods to handle. In addition, this article discusses how the new technique can be used as a visual monitoring tool for identifying biased measured variables. 相似文献
53.
T.N. Sriram 《Sequential Analysis》2013,32(3-4):247-252
Sequential bootstrapping for branching processes with immigration is proposed. The asymptotic validity of a sequential bootstrap estimator of the offspring mean in is estabilished for all values of m ? (0, 1]. This result is to be constrasted with the standard (non-sequential)bootstrapping where the bootstrap estimator estimator has been shown to asymptotically invalid (see, Sriram (1992)). 相似文献
54.
Wireless networks play a very important role in today’s modern world, convincingly surpassing the wired infrastructure in
terms of popularity. Hence, it is important to ensure that services which access wired networks should also be accessible
using a wireless network without any performance degradation. One of the most common variants in wireless communications is
the Wireless Mesh Network (WMNs). WMNs exploit multi-hop wireless communications between wireless access points. Hence, the
effective bandwidth decreases as the number of hops increases in a WMN, thus increasing latency and resulting in reduced performance.
This may be due to spatial contention, multipath fading, interference or inefficient queuing mechanisms etc. Here we take
queuing mechanisms into consideration and study the QMMN algorithm (Queue Management for Multi-hop Networks) which tends to
improve throughput, fairness and reduce global synchronization problems. Based on our study, we implement a modified version
of the QMMN algorithm, otherwise called the Enhanced QMMN (EQMMN) algorithm. EQMMN can be considered an effective algorithm
which solves the problem of fairness between flows (either responsive or unresponsive) and eventually improves TCP throughput
at wireless access points. Our experimental results prove that EQMMN algorithms have better performance characteristics such
as throughput (TCP) and fairness index compared to QMMN algorithms. 相似文献
55.
David Griffith Kotikalapudi Sriram Liliya Krivulina Nada Golmie 《Optical Switching and Networking》2005,2(2):127-136
The introduction of new high bandwidth services such as video-on-demand by cable operators will put a strain on existing resources. It is important for cable operators to know how many resources to commit to the network to satisfy customer demands. In this paper, we develop models of voice and video traffic to determine the effect of demand growth on hybrid fiber–coax networks. We obtain a set of guidelines that network operators can use to build out their networks in response to increased demand. We begin with one type of traffic and generalize to an arbitrary number of high-bandwidth constant bit rate (CBR) like services to obtain service blocking probabilities. We consider the effect of supporting variable bit rate (VBR) packet-switched traffic in addition to CBR services. These computations help us to determine how cable networks would function under various conditions (i.e., low, medium, and heavy loads). We also consider how the growth rate of the popularity of such services would change over time, and how this impacts network planning. Our findings will help cable operators estimate how much bandwidth they need to provision for a given traffic growth model and connection blocking requirement. 相似文献
56.
Structure‐Guided Design of Thiazolidine Derivatives as Mycobacterium tuberculosis Pantothenate Synthetase Inhibitors 下载免费PDF全文
Parthiban Brindha Devi Ganesh Samala Jonnalagadda Padma Sridevi Shalini Saxena Mallika Alvala Elena G. Salina Prof. Dharmarajan Sriram Prof. Perumal Yogeeswari 《ChemMedChem》2014,9(11):2538-2547
The pantothenate biosynthetic pathway is essential for the persistent growth and virulence of Mycobacterium tuberculosis (Mtb) and one of the enzymes in the pathway, pantothenate synthetase (PS, EC: 6.3.2.1), encoded by the panC gene, has become an appropriate target for new therapeutics to treat tuberculosis. Herein, we report nanomolar thiazolidine inhibitors of Mtb PS developed by a rational inhibitor design approach. The thiazolidine compounds were discovered by using energy‐based pharmacophore modelling and subsequent in vitro screening, which resulted in compounds with a half maximal inhibitory concentration (IC50) value of (1.12±0.12) μM . These compounds were subsequently optimised by a combination of modelling and synthetic chemistry. Hit expansion of the lead by chemical synthesis led to an improved inhibitor with an IC50 value of 350 nM and an Mtb minimum inhibitory concentration (MIC) of 1.55 μM . Some of these compounds also showed good activity against dormant Mtb cells. 相似文献
57.
Sivacarendran Balendhran Sumeet Walia Hussein Nili Sharath Sriram Madhu Bhaskaran 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(6):640-652
The fascinating electronic and optoelectronic properties of free‐standing graphene has led to the exploration of alternative two‐dimensional materials that can be easily integrated with current generation of electronic technologies. In contrast to 2D oxide and dichalcogenides, elemental 2D analogues of graphene, which include monolayer silicon (silicene), are fast emerging as promising alternatives, with predictions of high degree of integration with existing technologies. This article reviews this emerging class of 2D elemental materials – silicene, germanene, stanene, and phosphorene – with emphasis on fundamental properties and synthesis techniques. The need for further investigations to establish controlled synthesis techniques and the viability of such elemental 2D materials is highlighted. Future prospects harnessing the ability to manipulate the electronic structure of these materials for nano‐ and opto‐electronic applications are identified. 相似文献
58.
Philipp Gutruf Eike Zeller Sumeet Walia Hussein Nili Sharath Sriram Madhu Bhaskaran 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(35):4532-4539
The concept of realizing electronic applications on elastically stretchable “skins” that conform to irregularly shaped surfaces is revolutionizing fundamental research into mechanics and materials that can enable high performance stretchable devices. The ability to operate electronic devices under various mechanically stressed states can provide a set of unique functionalities that are beyond the capabilities of conventional rigid electronics. Here, a distinctive microtectonic effect enabled oxygen‐deficient, nanopatterned zinc oxide (ZnO) thin films on an elastomeric substrate are introduced to realize large area, stretchable, transparent, and ultraportable sensors. The unique surface structures are exploited to create stretchable gas and ultraviolet light sensors, where the functional oxide itself is stretchable, both of which outperform their rigid counterparts under room temperature conditions. Nanoscale ZnO features are embedded in an elastomeric matrix function as tunable diffraction gratings, capable of sensing displacements with nanometre accuracy. These devices and the microtectonic oxide thin film approach show promise in enabling functional, transparent, and wearable electronics. 相似文献
59.
Yeonsik Jeong Sriram Lakshmanan Sandeep Kakumanu Raghupathy Sivakumar 《Wireless Networks》2011,17(3):567-582
In this paper we present a new approach called cue-based networking that uses hints or cues about the physical environment to optimize networked application behavior. We define the notion of
cues and describe how cues can be obtained using wireless sensor networks as the underlying platform. We identify both the
research and system challenges that need to be addressed to realize benefits of the approach under a target application of
video delivery over IP networks. In the process, we identify key challenges of wireless sensor networks, namely timeliness
and robustness. We design an adaptive algorithm that balances the tradeoff between them satisfying both timeliness and robustness
requirements. Through an implementation of the video delivery application using the proposed algorithm in a real home environment,
we highlight the practical benefits of the proposed approach. 相似文献
60.
Madhu Bhaskaran Sharath Sriram Simon Ruffell Arnan Mitchell 《Advanced functional materials》2011,21(12):2251-2257
We report on the use of nanoindentation to characterize in situ the voltage and current generation of piezoelectric thin films. This work presents the controlled observation of nanoscale piezoelectric voltage and current generation, allowing accurate quantification and mapping of force function variations. We characterize both continuous thin films and lithographically patterned nanoislands with constrained interaction area. The influence of size on energy generation parameters is reported, demonstrating that nanoislands can exhibit more effective current generation than continuous films. This quantitative finding suggests that further research into the impact of nanoscale patterning of piezoelectric thin films may yield an improved materials platform for integrated microscale energy scavenging systems. 相似文献