scholarly journals Performance of Dynamic Optical Path Networks with Large-scale WBSS-based Optical Cross-connects

Author(s):  
Hai-Chau Le ◽  
Anh Ngoc Le ◽  
Thi Viet Huong Pham ◽  
Thanh Hai Dao

In this paper, we have proposed a generalized large-scale optical cross-connect (OXC) architecture utilizing waveband selective switches (WBSS) for realizing future cost-effective, bandwidth-abundant and flexible optical networks. The developed architecture implements multiple WBSSs for each incoming fiber and small size wavelength selective switches (WSSs) for dropping optical paths while simply deploying 1´2 WSSs or 1´2 optical couplers for realizing the adding function. Thanks to the use of WBSSs, which are more cost-effective and simpler devices, the developed architecture enables a significant hardware scale reduction. The WBSS-based OXC, however, suffers from a limited routing capability, which relies on the inner node parameter (i.e., the WBSS number per input fiber) and the waveband granularity of WBSSs. We, therefore, evaluate the hardware scale requirement of our developed architecture in comparison with that of conventional WSS-based OXC. It is verified that a substantial hardware scale reduction can be achieved by using the proposed architecture, especially for high port count OXCs or when applying coarser granular WBSSs. Moreover, we also assess the performance of dynamic optical networks based on the proposed OXC. Numerical simulations show that the network offers a substantial necessary hardware scale reduction at the cost of a small performance offset comparing to that of the network using conventional WSS-based OXC.

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1646
Author(s):  
Jingya Xie ◽  
Wangcheng Ye ◽  
Linjie Zhou ◽  
Xuguang Guo ◽  
Xiaofei Zang ◽  
...  

In the last couple of decades, terahertz (THz) technologies, which lie in the frequency gap between the infrared and microwaves, have been greatly enhanced and investigated due to possible opportunities in a plethora of THz applications, such as imaging, security, and wireless communications. Photonics has led the way to the generation, modulation, and detection of THz waves such as the photomixing technique. In tandem with these investigations, researchers have been exploring ways to use silicon photonics technologies for THz applications to leverage the cost-effective large-scale fabrication and integration opportunities that it would enable. Although silicon photonics has enabled the implementation of a large number of optical components for practical use, for THz integrated systems, we still face several challenges associated with high-quality hybrid silicon lasers, conversion efficiency, device integration, and fabrication. This paper provides an overview of recent progress in THz technologies based on silicon photonics or hybrid silicon photonics, including THz generation, detection, phase modulation, intensity modulation, and passive components. As silicon-based electronic and photonic circuits are further approaching THz frequencies, one single chip with electronics, photonics, and THz functions seems inevitable, resulting in the ultimate dream of a THz electronic–photonic integrated circuit.


2002 ◽  
Vol 06 (24) ◽  
pp. 958-965
Author(s):  
Jun Yu ◽  
Jian Wang ◽  
Huanming Yang

A coordinated international effort to sequence agricultural and livestock genomes has come to its time. While human genome and genomes of many model organisms (related to human health and basic biological interests) have been sequenced or plugged in the sequencing pipelines, agronomically important crop and livestock genomes have not been given high enough priority. Although we are facing many challenges in policy-making, grant funding, regional task emphasis, research community consensus and technology innovations, many initiatives are being announced and formulated based on the cost-effective and large-scale sequencing procedure, known as whole genome shotgun (WGS) sequencing that produces draft sequences covering a genome from 95 percent to 99 percent. Identified genes from such draft sequences, coupled with other resources, such as molecular markers, large-insert clones and cDNA sequences, provide ample information and tools to further our knowledge in agricultural and environmental biology in the genome era that just comes to its accelerated period. If the campaign succeeds, molecular biologists, geneticists and field biologists from all countries, rich or poor, would be brought to the same starting point and expect another astronomical increase of basic genomic information, ready to convert effectively into knowledge that will ultimately change our lives and environment into a greater and better future. We call upon national and international governmental agencies and organizations as well as research foundations to support this unprecedented movement.


2021 ◽  
Author(s):  
Y. Natalia Alfonso ◽  
Adnan A Hyder ◽  
Olakunle Alonge ◽  
Shumona Sharmin Salam ◽  
Kamran Baset ◽  
...  

Abstract Drowning is the leading cause of death among children 12-59 months old in rural Bangladesh. This study evaluated the cost-effectiveness of a large-scale crèche intervention in preventing child drowning. Estimates of the effectiveness of the crèches was based on prior studies and the program cost was assessed using monthly program expenditures captured prospectively throughout the study period from two different implementing agencies. The study evaluated the cost-effectiveness from both a program and societal perspective. Results showed that from the program perspective the annual operating cost of a crèche was $416.35 (95%C.I.: $222 to $576), the annual cost per child was $16 (95%C.I.: $9 to $22) and the incremental-cost-effectiveness ratio (ICER) per life saved with the crèches was $17,803 (95%C.I.: $9,051 to $27,625). From the societal perspective (including parents time valued) the ICER per life saved was -$176,62 (95%C.I.: -$347,091 to -$67,684)—meaning crèches generated net economic benefits per child enrolled. Based on the ICER per disability-adjusted-life years averted from the societal perspective (excluding parents time), $2,020, the crèche intervention was cost-effective even when the societal economic benefits were ignored. Based on the evidence, the creche intervention has great potential for reducing child drowning at a cost that is reasonable.


2019 ◽  
Vol 3 (7) ◽  
pp. 1600-1622 ◽  
Author(s):  
Ji-Lu Zheng ◽  
Ya-Hong Zhu ◽  
Ming-Qiang Zhu ◽  
Kang Kang ◽  
Run-Cang Sun

The commercial production of advanced fuels based on bio-oil gasification could be promising because the cost-effective transport of bio-oil could promote large-scale implementation of this biomass technology.


2020 ◽  
Vol 79 (2) ◽  
pp. 105-113
Author(s):  
Abdul Bari Muneera Parveen ◽  
Divya Lakshmanan ◽  
Modhumita Ghosh Dasgupta

The advent of next-generation sequencing has facilitated large-scale discovery and mapping of genomic variants for high-throughput genotyping. Several research groups working in tree species are presently employing next generation sequencing (NGS) platforms for marker discovery, since it is a cost effective and time saving strategy. However, most trees lack a chromosome level genome map and validation of variants for downstream application becomes obligatory. The cost associated with identifying potential variants from the enormous amount of sequence data is a major limitation. In the present study, high resolution melting (HRM) analysis was optimized for rapid validation of single nucleotide polymorphisms (SNPs), insertions or deletions (InDels) and simple sequence repeats (SSRs) predicted from exome sequencing of parents and hybrids of Eucalyptus tereticornis Sm. ? Eucalyptus grandis Hill ex Maiden generated from controlled hybridization. The cost per data point was less than 0.5 USD, providing great flexibility in terms of cost and sensitivity, when compared to other validation methods. The sensitivity of this technology in variant detection can be extended to other applications including Bar-HRM for species authentication and TILLING for detection of mutants.


1997 ◽  
Vol 36 (8-9) ◽  
pp. 307-311 ◽  
Author(s):  
R. Y. G. Andoh ◽  
C. Declerck

Rapid urbanisation and its consequent increase in impermeable surface areas and changes in land use has generally resulted in problems of flooding and heavy pollution of urban streams and other receiving waters. This has often been coupled with ground water depletion and a threat to water resources. The first part of this paper presents an alternative drainage philosophy and strategy which mimics nature's way by slowing down (attenuating) the movement of urban runoff. This approach results in cost-effective, affordable and sustainable drainage schemes. The alternative strategy can be described as one of prevention rather than cure by effecting controls closer to source rather than the traditional approach which results in the transfer of problems downstream, resulting in its cumulation and the need for large scale, centralised control. The second part describes a research project which has been launched in order to quantify the cost and operational benefits of source control and distributed storage. Details of the methodology of the modelling and simulation processes which are being followed to achieve this target are presented.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Alexandros Tsipianitis ◽  
Yiannis Tsompanakis

Liquid-filled tanks are effective storage infrastructure for water, oil, and liquefied natural gas (LNG). Many such large-scale tanks are located in regions with high seismicity. Therefore, very frequently base isolation technology has to be adopted to reduce the dynamic distress of storage tanks, preventing the structure from typical modes of failure, such as elephant-foot buckling, diamond-shaped buckling, and roof damage caused by liquid sloshing. The cost-effective seismic design of base-isolated liquid storage tanks can be achieved by adopting performance-based design (PBD) principles. In this work, the focus is given on sliding-based systems, namely, single friction pendulum bearings (SFPBs), triple friction pendulum bearings (TFPBs), and mainly on the recently developed quintuple friction pendulum bearings (QFPBs). More specifically, the study is focused on the fragility analysis of tanks isolated by sliding-bearings, emphasizing on isolators’ displacements due to near-fault earthquakes. In addition, a surrogate model has been developed for simulating the dynamic response of the superstructure (tank and liquid content) to achieve an optimal balance between computational efficiency and accuracy.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4042
Author(s):  
Gürkan Kumbaroğlu ◽  
Cansu Canaz ◽  
Jonathan Deason ◽  
Ekundayo Shittu

This paper focuses on the interdependent relationship of power generation, transportation and CO2 emissions to evaluate the impact of electric vehicle deployment on power generation and CO2 emissions. The value of this evaluation is in the employment of a large-scale, bottom-up, national energy modeling system that encompasses the complex relationships of producing, transforming, transmitting and supplying energy to meet the useful demand characteristics with great technological detail. One of such models employed in this analysis is the BUEMS model. The BUEMS model provides evidence of win-win policy options that lead to profitable decarbonization using Turkey’s data in BUEMS. Specifically, the result shows that a ban on diesel fueled vehicles reduces lifetime emissions as well as lifetime costs. Furthermore, model results highlight the cost-effective emission reduction potential of e-buses in urban transportation. More insights from the results indicate that the marginal cost of emission reduction through e-bus transportation is much lower than that through other policy measures such as carbon taxation in transport. This paper highlights the crucial role the electricity sector plays in the sustainability of e-mobility and the value of related policy prescriptions.


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