Future evolution of optical networks - minimising cost while maximising performance

2006 ◽  
Author(s):  
D. Payne
Keyword(s):  
Optical Networks ◽  
Future Evolution

Sparse Placement of Wavelength Convertible 3R Regenerators and Joint Resource Assignment in Large-Scale Optical Networks

2013 ◽  
Vol E96.B (7) ◽  
pp. 1845-1856
Author(s):  
Xin WANG ◽  
Filippos BALASIS ◽  
Sugang XU ◽  
Yoshiaki TANAKA
Keyword(s):  
Optical Networks ◽  
Large Scale ◽  
Resource Assignment

Analysis of Inter-Satellite Optical Wireless Communication System

2017 ◽  
Vol 7 (10) ◽  
pp. 10
Author(s):  
Rajbir Singh
Keyword(s):  
Wireless Communication ◽  
Optical Networks ◽  
Data Transmission ◽  
High Speed ◽  
Open Space ◽  
Communication Link ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
High Speed Data ◽  
Speed Data Transmission

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.

On the identity of socialism in modern China

2019 ◽  
pp. 75-89
Author(s):  
A.B. Lyubinin
Keyword(s):  
Economic System ◽  
Modern China ◽  
Soviet Society ◽  
Chinese Society ◽  
Transitional Form ◽  
Global Development ◽  
Future Evolution ◽  
The Future ◽  
Marxist Concept

The article comments on the concept of «socialism with Chinese specificity», which forms the ideological basis of the «Chinese miracle». The ideological origins of this concept, starting with Confucianism, are revealed. It has evolved to become increasingly pragmatic and to adapt to the realities of national and global development. The relation of this concept with the Marxist concept of socialism is shown. The article substantiates the fundamental theoretical thesis that in the objective-essential sense (in the elimination of, in particular, national specifics) Chinese society is a transitional form to socialism (a certain analogue of the Soviet society of the NEP period). The author talks about a «heterogeneous», «mixed» socio-economic system, the vector and nature of the future evolution of which will depend crucially on the strategic course of the CPC.

Performance Modeling and Analysis of WDM Optical Networks under Wavelength Continuity Constraint using MILP

2020 ◽  
Vol 13 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Swati Bhalaik ◽  
Ashutosh Sharma ◽  
Rajiv Kumar ◽  
Neeru Sharma
Keyword(s):  
Network Design ◽  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Optical Network ◽  
Optimal Path ◽  
Topology Design ◽  
Mixed Integer ◽  
Wdm Optical Networks ◽  
Virtual Topology ◽  
Wdm Network

Objective: Optical networks exploit the Wavelength Division Multiplexing (WDM) to meet the ever-growing bandwidth demands of upcoming communication applications. This is achieved by dividing the enormous transmission bandwidth of fiber into smaller communication channels. The major problem with WDM network design is to find an optimal path between two end users and allocate an available wavelength to the chosen path for the successful data transmission. Methods: This communication over a WDM network is carried out through lightpaths. The merging of all these lightpaths in an optical network generates a virtual topology which is suitable for the optimal network design to meet the increasing traffic demands. But, this virtual topology design is an NP-hard problem. This paper aims to explore Mixed Integer Linear Programming (MILP) framework to solve this design issue. Results: The comparative results of the proposed and existing mathematical models show that the proposed algorithm outperforms with the various performance parameters. Conclusion: Finally, it is concluded that network congestion is reduced marginally in the overall performance of the network.

Experimental demonstration of optical prefiltering in WDM-SCM optical networks employing ultraselective optical bandpass filter

1999 ◽  
Vol 35 (4) ◽  
pp. 318 ◽  
Author(s):  
J. Capmany ◽  
D. Pastor ◽  
A. León ◽  
P. Chamorro ◽  
D. Santos
Keyword(s):  
Optical Networks ◽  
Bandpass Filter ◽  
Experimental Demonstration

scholarly journals Depletion of groundwater resources under rapid urbanisation in Africa: recent and future trends in the Nairobi Aquifer System, Kenya

2020 ◽  
Vol 28 (8) ◽  
pp. 2635-2656
Author(s):  
Samson Oiro ◽  
Jean-Christophe Comte ◽  
Chris Soulsby ◽  
Alan MacDonald ◽  
Canute Mwakamba
Keyword(s):  
Negative Impact ◽  
Groundwater Resources ◽  
Climatic Data ◽  
Groundwater Abstraction ◽  
Management Scenarios ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Future Evolution ◽  
Level Data ◽  
Groundwater Assessment

AbstractThe Nairobi volcano-sedimentary regional aquifer system (NAS) of Kenya hosts >6 M people, including 4.7 M people in the city of Nairobi. This work combines analysis of multi-decadal in-situ water-level data with numerical groundwater modelling to provide an assessment of the past and likely future evolution of Nairobi’s groundwater resources. Since the mid-1970s, groundwater abstraction has increased 10-fold at a rate similar to urban population growth, groundwater levels have declined at a median rate of 6 m/decade underneath Nairobi since 1950, whilst built-up areas have increased by 70% since 2000. Despite the absence of significant trends in climatic data since the 1970s, more recently, drought conditions have resulted in increased applications for borehole licences. Based on a new conceptual understanding of the NAS (including insights from geophysics and stable isotopes), numerical simulations provide further quantitative estimates of the accelerating negative impact of abstraction and capture the historical groundwater levels quite well. Analysis suggests a groundwater-level decline of 4 m on average over the entire aquifer area and up to 46 m below Nairobi, net groundwater storage loss of 1.5 billion m3 and 9% river baseflow reduction since 1950. Given current practices and trajectories, these figures are predicted to increase six-fold by 2120. Modelled future management scenarios suggest that future groundwater abstraction required to meet Nairobi projected water demand is unsustainable and that the regional anthropogenically-driven depletion trend can be partially mitigated through conjunctive water use. The presented approach can inform groundwater assessment for other major African cities undergoing similar rapid groundwater development.

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