Development of stability-preserving time-limited model reduction framework for 2-D and 1-D models with error bound

Due to their complex structure, 2-Dmodels are challenging towork with; additionally, simulation, analysis, design, and control get increasingly difficult as the order of the model grows. Moreover, in particular time intervals, Gawronski and Juang’s timelimited model reduction schemes produce an unstable reduced-order model for the 2-D and 1-D models. Researchers revealed some stability preservation solutions to address this key flaw which ensure the stability of 1-D reduced-order systems; nevertheless, these strategies result in large approximation errors. However, to the best of the authors’ knowledge, there is no literature available for the stability preserving time-limited-interval Gramian-based model reduction framework for the 2-D discrete-time systems. In this article, 2-D models are decomposed into two separate sub-models (i.e., two cascaded 1-D models) using the condition of minimal rank-decomposition. Model reduction procedures are conducted on these obtained two 1-D sub-models using limited-time Gramian. The suggestedmethodology works for both 2-D and 1-Dmodels. Moreover, the suggested methodology gives the stability of the reduced model as well as a priori error-bound expressions for the 2-D and 1-D models. Numerical results and comparisons between existing and suggested methodologies are provided to demonstrate the effectiveness of the suggested methodology.     

Network Functions Virtualization for Mobile Core and Heterogeneous Cellular Networks

Wireless Personal Communications - Network Functions Virtualization (NFV) is a network architecture concept to improve network performance. This concept empowers the network capacities and reduces...     

MapReduce scheduling algorithms: a review

Recent trends in big data have shown that the amount of data continues to increase at an exponential rate. This trend has inspired many researchers over the past few years to explore new research direction of studies related to multiple areas of big data. The widespread popularity of big data processing platforms using MapReduce framework is the growing demand to further optimize their performance for various purposes. In particular, enhancing resources and jobs scheduling are becoming critical since they fundamentally determine whether the applications can achieve the performance goals in different use cases. Scheduling plays an important role in big data, mainly in reducing the execution time and cost of processing. This paper aims to survey the research undertaken in the field of scheduling in big data platforms. Moreover, this paper analyzed scheduling in MapReduce on two aspects: taxonomy and performance evaluation. The research progress in MapReduce scheduling algorithms is also discussed. The limitations of existing MapReduce scheduling algorithms and exploit future research opportunities are pointed out in the paper for easy identification by researchers. Our study can serve as the benchmark to expert researchers for proposing a novel MapReduce scheduling algorithm. However, for novice researchers, the study can be used as a starting point.

     

ATM test-bed architecture for training purposes

Due to the recent tremendous growth in ATM products, there is a strong need for training and education for engineers working in the field of ATM networks. This paper describes the architecture of an ATM test-bed that can be used to provide such training. Copyright © 2001 John Wiley & Sons, Ltd.     

Nanoimprint lithography for optic fluidics with phase gratings for environmental monitoring application

Optic fluidic devices, which combine optical elements such as adaptive optical lenses or diffraction gratings into micro-fluidic devices, are now becoming increasingly important for environmental monitoring, medical diagnostics and chemical detection. In this paper, we present a novel and simple micro/nanofabrication process for SU-8 based optic fluidics structures with phase gratings on the bottom of the micro-channel using our silicon grating templates. The refraction index difference between the fluid and the SU-8 gratings generates a modulation in the phase of the light passing through the device. Our method of fabricating optic fluidic device is promising to be economic in fabrication, high throughput in production and have potential applications for sensing.     

Salt-induced modulation in inorganic nutrients, antioxidant enzymes, proline content and seed oil composition in safflower (Carthamus tinctorius L.)

BACKGROUND: Safflower (Carthamus tinctorius L.) has gained considerable ground as a potential oil‐seed crop. However, its yield and oil production are adversely affected under saline conditions. The present study was conducted to appraise the influence of salt (NaCl) stress on yield, accumulation of different inorganic elements, free proline and activities of some key antioxidant enzymes in plant tissues as well as seed oil components in safflower. Two safflower accessions differing in salt tolerance (Safflower‐33 (salt sensitive) and Safflower‐39 (salt tolerant)) were grown under saline (150 mmol L^?1) conditions and salt‐induced changes in the earlier‐mentioned physiological attributes were determined. RESULTS: Salt stress enhanced leaf and root Na⁺, Cl^? and proline accumulation and activities of leaf superoxide dismutase, catalase and peroxidase, while it decreased K⁺, Ca²⁺ and K⁺/Ca²⁺ and Ca²⁺/Na⁺ ratios and seed yield, 100‐seed weight, number of seeds, as well as capitula, seed oil contents and oil palmitic acid. No significant effect of salt stress was observed on seed oil α‐tocopherols, stearic acid, oleic acid or linoleic acid contents. Of the two safflower lines, salt‐sensitive Safflower‐33 was higher in leaf and root Na⁺ and Cl^?, while Safflower‐39 was higher in leaf and root K⁺, K⁺/Ca²⁺ and Ca²⁺/Na⁺ and seed yield, 100‐seed weight, catalase activity, seed oil contents, seed oil α‐tocopherol and palmitic acid. Other attributes remained almost unaffected in both accessions. CONCLUSION: Overall, high salt tolerance of Safflower‐39 could be attributed to Na⁺ and Cl^? exclusion, high accumulation of K⁺ and free proline, enhanced CAT activity, seed oil α‐tocopherols and palmitic acid contents. Copyright © 2011 Society of Chemical Industry     

Feature aggregation based visual attention model for video summarization

Video summarization is an integral component of video archiving systems. It provides small versions of the videos that are suitable for enhancing browsing and navigation capabilities. A popular method to generate summaries is to extract a set of key frames from the video, which conveys the overall message of the video. This paper introduces a novel feature aggregation based visual saliency detection mechanism and its usage for extracting key frames. The saliency maps are computed based on the aggregated features and motion intensity. A non-linear weighted fusion mechanism combines the two saliency maps. On the resultant map, a Gaussian weighting scheme is used to assign more weight to the pixels close to the center of the frame. Based on the final attention value of each frame, the key frames are extracted adaptively. The experimental results, based on different evaluation standards, demonstrate that the proposed scheme extracts semantically significant key frames.     

圆弧焊接薄壁圆筒残余应力场的分析研究

由于圆弧焊接的薄壁圆筒在高科技工程,如航空机器、压力容器和核工程中的广泛应用,对焊接导致的如焊接变形和残余应力等缺陷的研究就显得非常重要。介绍了一个计算程序,用以分析低碳钢薄壁圆筒在圆弧焊接中的温度分布以及随后将产生的残余应力场。基于数值模拟的参数研究用于分析焊接所产生的残余应力中的关键参数的影响。考虑了低碳钢、焊丝和双椭圆热源模型的基于温度的热机械性能。通过全尺寸焊接试验中的瞬时温度分布和残余应力场证实了有限元模拟方法的精确性。其目的在于提供数据以证实薄壁圆筒现有焊接工艺的有效性,从而将预加应力导致的结构在使用期间失效的可能性降至最低。