1,434 research outputs found
Exploring the Role of Enterprise Architecture in IS-enabled Ot: An EA Principles Perspective
© 2016 IEEE. Although EA principles have received considerable attention in recent years, there is still little known about how EA principles can be used to govern the transformation of the Information Systems enabled organization. In this research-in-progress paper, we communicate our initial step towards answering the sub-question: how do enforcing EA principles contribute to IS-enabled OT? Based on a comprehensive literature review, we initially propose five testable hypotheses and a research model, which is a pre-requisite to developing a data-driven theory for this important area of research. It is anticipated that the ensuing theory will provide a basis for further research studying the impact of EA on IS-enabled OT. The tested research model will also provide guidance to practitioners on how to effectively design and use EA principles in managing transformative changes caused by IS within their organizations and overall industry sectors
Pore-scale modeling of two-phase flow: a comparison of the generalized network model to direct numerical simulation
Despite recent advances in pore-scale modeling of two-phase flow through porous media, the relative strengths and limitations of various modeling approaches have been largely unexplored. In this work, two-phase flow simulations from the generalized network model (GNM) [Phys. Rev. E 96, 013312 (2017)2470-004510.1103/PhysRevE.96.013312; Phys. Rev. E 97, 023308 (2018)2470-004510.1103/PhysRevE.97.023308] are compared with a recently developed lattice-Boltzmann model (LBM) [Adv. Water Resour. 116, 56 (2018)0309-170810.1016/j.advwatres.2018.03.014; J. Colloid Interface Sci. 576, 486 (2020)0021-979710.1016/j.jcis.2020.03.074] for drainage and waterflooding in two samples-a synthetic beadpack and a micro-CT imaged Bentheimer sandstone-under water-wet, mixed-wet, and oil-wet conditions. Macroscopic capillary pressure analysis reveals good agreement between the two models, and with experiments, at intermediate saturations but shows large discrepancy at the end-points. At a resolution of 10 grid blocks per average throat, the LBM is unable to capture the effect of layer flow which manifests as abnormally large initial water and residual oil saturations. Critically, pore-by-pore analysis shows that the absence of layer flow limits displacement to invasion-percolation in mixed-wet systems. The GNM is able to capture the effect of layers, and exhibits predictions closer to experimental observations in water and mixed-wet Bentheimer sandstones. Overall, a workflow for the comparison of pore-network models with direct numerical simulation of multiphase flow is presented. The GNM is shown to be an attractive option for cost and time-effective predictions of two-phase flow, and the importance of small-scale flow features in the accurate representation of pore-scale physics is highlighted
GreenTouch GreenMeter core network power consumption models and results
This paper summarizes the energy efficiency improvement obtained by implementing a number of techniques in the core network investigated by the GreenTouch consortium. These techniques include the use of improved components with lower power consumption, mixed line rates (MLR), energy efficient routing, sleep and physical topology optimization. We consider an example continental network topology, NSFNET, to evaluate the total power consumption of a 2010 network and a 2020 network. The 2020 network results are based on traffic projections, the reductions in the equipment power consumption expected by 2020 and a range of energy saving measures considered by GreenTouch as outlined above. The projections of the 2020 equipment power consumption are based on two scenarios: a business as usual (BAU) scenario and a Green Touch (GT) (i.e. BAU+GT) scenario. The results show that the 2020 BAU scenario improves the network energy efficiency by a factor of 4.8x compared to the 2010 network as a result of the reduction in the network equipment power consumption. Considering the 2020 BAU+GT network where the equipment power consumption is reduced by a factor of 27x compared to the 2010 network, and where sleep, MLR and network topology are jointly optimized, a total improvement in energy efficiency of 64x is obtained
Evaluation of Antihypertensive Effect of Aqueous Methanol Extract of Caralluma tuberculata N.E.Br in Sprauge Dawley Rats
Purpose: To evaluate the phytochemical profile and antihypertensive effect of Caralluma tuberculata N.E.Br (AMECT).Methods: The antihypertensive effect of the aqueous methanol extract of (AMECT) was evaluated in both normotensive and hypertensive rats. In normotensive rats, various doses (100, 300 and 500 mg/kg body weight, p.o.) were administered at 0, 1, 3 and 6 hr intervals. Anti-hypertensive activity of the crude extract was investigated in three experimental hypertensive models, viz, egg-fed diet, glucose-induced and cadmium-induced hypertensive rats. Cardiovascular parameters, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and heart rate (HR) were measured by tail cuff method using non-invasive blood pressure apparatus (NIBP) attached. AMECT was also investigated for its phytochemical profile.Results: The results indicate that AMECT produced a dose-dependent, significant (p < 0.05) decrease in SBP, DBP, MBP, and HR (p < 0.01) of normotensive rats, when compared to control groups, at all test doses. The 500 mg/kg dose produced a highly significant effect (mm Hg, p < 0.001) in SBP (85.9 ± 7.2), DBP (71.86 ± 12.1), MBP (75.1 ± 11.7) and HR (238.08 ± 8.3 beats/min), in comparison to 100 and 300 mg/kg doses; therefore, 500 mg/kg was selected for antihypertensive test in egg-fed, glucose-induced and cadmium-treated hypertensive rats. Significant (p < 0.05) antihypertensive and negative chronotropic effects were observed in hypertensive models compared to their respective normal controls. Phytochemical analysis revealed the presence of tannins, alkaloids, phenolic compounds, cardiac glycosides and flavonoids.Conclusion: The findings indicate that Caralluma tuberculata possesses significant anti-hypentensive activity in rats.Keywords: Phytochemical profile, Antihypertensive, Cardiovascular, Caralluma tuberculata N.E.Br, Blood pressur
Energy Efficient Service Distribution in Internet of Things
The Internet of Things (IoT) networks are expected to involve myriad of devices, ranging from simple sensors to powerful single board computers and smart phones. The great advancement in computational power of embedded technologies have enabled the integration of these devices into the IoT network, allowing for cloud functionalities to be extended near to the source of data. In this paper we study a multi-layer distributed IoT architecture supported by fog and cloud. We optimize the placement of the IoT services in this architecture so that the total power consumption is minimized. Our results show that, introducing local computation at the IoT layer can bring up to 90% power savings compared with general purpose servers in a central cloud
Energy Efficient Service Distribution in Internet of Things
The Internet of Things (IoT) networks are expected to involve myriad of devices, ranging from simple sensors to powerful single board computers and smart phones. The great advancement in computational power of embedded technologies have enabled the integration of these devices into the IoT network, allowing for cloud functionalities to be extended near to the source of data. In this paper we study a multi-layer distributed IoT architecture supported by fog and cloud. We optimize the placement of the IoT services in this architecture so that the total power consumption is minimized. Our results show that, introducing local computation at the IoT layer can bring up to 90% power savings compared with general purpose servers in a central cloud
Noiseless nonreciprocity in a parametric active device
Nonreciprocal devices such as circulators and isolators belong to an
important class of microwave components employed in applications like the
measurement of mesoscopic circuits at cryogenic temperatures. The measurement
protocols usually involve an amplification chain which relies on circulators to
separate input and output channels and to suppress backaction from different
stages on the sample under test. In these devices the usual reciprocal symmetry
of circuits is broken by the phenomenon of Faraday rotation based on magnetic
materials and fields. However, magnets are averse to on-chip integration, and
magnetic fields are deleterious to delicate superconducting devices. Here we
present a new proposal combining two stages of parametric modulation emulating
the action of a circulator. It is devoid of magnetic components and suitable
for on-chip integration. As the design is free of any dissipative elements and
based on reversible operation, the device operates noiselessly, giving it an
important advantage over other nonreciprocal active devices for quantum
information processing applications.Comment: 17 pages, 4 figures + 12 pages Supplementary Informatio
Pure angular momentum generator using a ring resonator
Author name used in this publication: X. M. ZhangAuthor name used in this publication: D. P. Tsai2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Directed differentiation of human pluripotent stem sells for the generation of high-order kidney organoids
Our understanding in the inherent properties of human pluripotent stem cells (hPSCs) have made possible the development of differentiation procedures to generate three-dimensional tissue-like cultures, so-called organoids. Here we detail a stepwise methodology to generate kidney organoids from hPSCs. This is achieved through direct differentiation of hPSCs in two-dimensional monolayer culture toward the posterior primitive streak fate, followed by induction of intermediate mesoderm-committed cells, which are further aggregated and cultured in three-dimensions to generate kidney organoids containing segmented nephron-like structures in a process that lasts 20 days. We also provide a concise description on how to assess renal commitment during the time course of kidney organoid generation. This includes the use of flow cytometry and immunocytochemistry analyses for the detection of specific renal differentiation markers
- …