Traffic congestion in interconnected complex networks

Traffic congestion in isolated complex networks has been investigated extensively over the last decade. Coupled network models have recently been developed to facilitate further understanding of real complex systems. Analysis of traffic congestion in coupled complex networks, however, is still relatively unexplored. In this paper, we try to explore the effect of interconnections on traffic congestion in interconnected BA scale-free networks. We find that assortative coupling can alleviate traffic congestion more readily than disassortative and random coupling when the node processing capacity is allocated based on node usage probability. Furthermore, the optimal coupling probability can be found for assortative coupling. However, three types of coupling preferences achieve similar traffic performance if all nodes share the same processing capacity. We analyze interconnected Internet AS-level graphs of South Korea and Japan and obtain similar results. Some practical suggestions are presented to optimize such real-world interconnected networks accordingly.Comment: 8 page

Workforce-Planning-and-Development.pdf

This paper includes a survey of different training courses and resources available to councils, and outlines some key elements which might form part of any programme on workforce planning and development

Enhancement Of Methodology And Definition For Serial Protocol Electrical Specification Compatibility For Non-Compliant Fpga

A new methodology and definition for a clearer compatibility for middle-range and low-end Field Programmable Gate Array (FPGA) transceiver is presented in this research. It has been a big challenge to balance between cost and performance in order to meet the full industrial protocol specification for middle-range and low-end FPGA. When the products are not able to achieve full protocol specification, the company will still market these products and claim that they are compatible. With this kind of situation, there are no guidelines can be followed; hence, users will not have confidence to design the product. In this research, a clearer compatible specification is obtained to provide channel loss requirement by extracting the timing margin at different test points. The research also ensures that quantifiable margin is allocated when compatible specification is defined. The middle-range FPGA that used in this research is Arria V GT device to define the new compatible specification with reference to IEEE 10GBASE-KR protocol where the compatible specification is used for board-based 10Gbps applications. The methodology used is by extracting the timing margin and find out the channel loss from 3 different test points which include Scenario 1) Transmitter is Arria V GT; Receiver is Compliant Receiver, Scenario 2) Transmitter and Receiver are from Arria V GT and Scenario 3) Transmitter is Compliant Transmitter; Receiver is from Arria V GT. 16-ps of timing margin is obtained from the research, while the channel loss for Scenario 1 is -16dB, Scenario 2 is -12dB and Scenario 3 is -17dB with error-free transfer for BER10-12

How volatilities nonlocal in time affect the price dynamics in complex financial systems

What is the dominating mechanism of the price dynamics in financial systems is of great interest to scientists. The problem whether and how volatilities affect the price movement draws much attention. Although many efforts have been made, it remains challenging. Physicists usually apply the concepts and methods in statistical physics, such as temporal correlation functions, to study financial dynamics. However, the usual volatility-return correlation function, which is local in time, typically fluctuates around zero. Here we construct dynamic observables nonlocal in time to explore the volatility-return correlation, based on the empirical data of hundreds of individual stocks and 25 stock market indices in different countries. Strikingly, the correlation is discovered to be non-zero, with an amplitude of a few percent and a duration of over two weeks. This result provides compelling evidence that past volatilities nonlocal in time affect future returns. Further, we introduce an agent-based model with a novel mechanism, that is, the asymmetric trading preference in volatile and stable markets, to understand the microscopic origin of the volatility-return correlation nonlocal in time.Comment: 16 pages, 7 figure

Urban Dreams of Migrants: A Case Study of Migrant Integration in Shanghai

Unprecedented human mobility has driven the rapid urbanization around the world. In China, the fraction of population dwelling in cities increased from 17.9% to 52.6% between 1978 and 2012. Such large-scale migration poses challenges for policymakers and important questions for researchers. To investigate the process of migrant integration, we employ a one-month complete dataset of telecommunication metadata in Shanghai with 54 million users and 698 million call logs. We find systematic differences between locals and migrants in their mobile communication networks and geographical locations. For instance, migrants have more diverse contacts and move around the city with a larger radius than locals after they settle down. By distinguishing new migrants (who recently moved to Shanghai) from settled migrants (who have been in Shanghai for a while), we demonstrate the integration process of new migrants in their first three weeks. Moreover, we formulate classification problems to predict whether a person is a migrant. Our classifier is able to achieve an F1-score of 0.82 when distinguishing settled migrants from locals, but it remains challenging to identify new migrants because of class imbalance. This classification setup holds promise for identifying new migrants who will successfully integrate into locals (new migrants that misclassified as locals).Comment: A modified version. The paper was accepted by AAAI 201