A Mamluk-Venetian Memorandum on Asian Trade, AD 1503

This article presents and discusses a source of unique importance for our knowledge of early modern global exchanges. Produced in 1503 by the Egyptian administration and found among the records of a Venetian company with global commercial interests, the document records hitherto unknown connections between the Arabian Peninsula, the Indian Subcontinent and Southeast Asia, followed by cargo figures. By sending the Memorandum to the head office in Venice, the Company's agents in Egypt were labouring to solve the most important concern of Venice's information network, that of coordinating Indian with Mediterranean trading seasons. By analysing the document's context, namely, a company involved in the export of central European metals to Asia, this article focuses on the capacity of its agents to gather information through collaboration, networking and ultimately, friendship with Muslim partners and informers. The story of the 1503 Memorandum and its transmission raises questions about the mixed networks underpinning global exchanges, the role of information and the drive of the late Mamluk sultanate into the world of the Indian Ocean.

The Hermitian Kirchhoff Index and Robustness of Mixed Graph

Large-scale social graph data poses significant challenges for social analytic tools to monitor and analyze social networks. The information-theoretic distance measure, namely, resistance distance, is a vital parameter for ranking influential nodes or community detection. The superiority of resistance distance and Kirchhoff index is that it can reflect the global properties of the graph fairly, and they are widely used in assessment of graph connectivity and robustness. There are various measures of network criticality which have been investigated for underlying networks, while little is known about the corresponding metrics for mixed networks. In this paper, we propose the positive walk algorithm to construct the Hermitian matrix for the mixed graph and then introduce the Hermitian resistance matrix and the Hermitian Kirchhoff index which are based on the eigenvalues and eigenvectors of the Hermitian Laplacian matrix. Meanwhile, we also propose a modified algorithm, the directed traversal algorithm, to select the edges whose removal will maximize the Hermitian Kirchhoff index in the general mixed graph. Finally, we compare the results with the algebraic connectivity to verify the superiority of the proposed strategy.

Cordon-Based Pricing Schemes for Mixed Urban-Freeway Networks using Macroscopic Fundamental Diagrams

The development of traffic models based on macroscopic fundamental diagrams (MFD) enables many real-time control strategies for urban networks, including cordon-based pricing schemes. However, most existing MFD-based pricing strategies are designed only to optimize the traffic-related performance, without considering the revenue collected by operators. In this study, we investigate cordon-based pricing schemes for mixed networks with urban networks and freeways. In this system, heterogeneous commuters choose their routes based on the user equilibrium principle. There are two types of operational objective for operating urban networks: (1) to optimize the urban network’s performance, that is, to maximize the outflux; and (2) to maximize the revenue for operators. To compare those two objectives, we first apply feedback control to design pricing schemes to optimize the urban network’s performance. Then, we formulate an optimal control problem to obtain the revenue-maximization pricing scheme. With numerical examples, we illustrate the difference between those pricing schemes.

End-to-end network slice architecture and distribution across 5G micro-operator leveraging multi-domain and multi-tenancy

Local 5G networks are emerging as a new form for 5G deployment, targeting service delivery for vertical-specific purposes and other local users. These networks are also known as micro-operator networks for which prior work has established different deployment scenarios, namely Closed, Open and Mixed Networks. To achieve network flexibility, customization and privacy required by various vertical sectors, such as industry, health and energy, it is essential to have a well-defined network slicing architecture and adequate implementation procedure. In this paper, a sophisticated end-to-end network slicing architecture is proposed for different deployment scenarios of the local 5G micro-operator concept. The proposed architecture incorporates a broad four-layer concept, leveraging a multi-tenancy layer for different tenants and their end users, a descriptive service layer, a multi-domain slicing management and orchestration layer, and a resource layer. We further propose a network slice instance (NSI) communication service distribution technique for local 5G micro-operators. This is achieved by expanding/leveraging the communication service management function in the multi-tenant layer into a multi-tenant manager and an orchestrator of communication services. In addition, we describe how the communication service orchestrator will address all the possible multitenant-slice situations during the distribution of a network slice instance to multiple tenants. The novel methods described in the paper present a solution for not only network slice communication service distribution across different micro-operator’s tenants but also for future use cases, especially, when the allocated slice is responsible for multiple tenants or when a tenant requests multiple NSIs.

Integrating Non-spiking Interneurons in Spiking Neural Networks

Researchers working with neural networks have historically focused on either non-spiking neurons tractable for running on computers or more biologically plausible spiking neurons typically requiring special hardware. However, in nature homogeneous networks of neurons do not exist. Instead, spiking and non-spiking neurons cooperate, each bringing a different set of advantages. A well-researched biological example of such a mixed network is a sensorimotor pathway, responsible for mapping sensory inputs to behavioral changes. This type of pathway is also well-researched in robotics where it is applied to achieve closed-loop operation of legged robots by adapting amplitude, frequency, and phase of the motor output. In this paper we investigate how spiking and non-spiking neurons can be combined to create a sensorimotor neuron pathway capable of shaping network output based on analog input. We propose sub-threshold operation of an existing spiking neuron model to create a non-spiking neuron able to interpret analog information and communicate with spiking neurons. The validity of this methodology is confirmed through a simulation of a closed-loop amplitude regulating network inspired by the internal feedback loops found in insects for posturing. Additionally, we show that non-spiking neurons can effectively manipulate post-synaptic spiking neurons in an event-based architecture. The ability to work with mixed networks provides an opportunity for researchers to investigate new network architectures for adaptive controllers, potentially improving locomotion strategies of legged robots.

VoIP Security: A Performance and Cost-benefit Analysis

Voice over IP (VoIP) has become the standard technology for telephony and has replaced the old Public Switched Telephone Network (PSTN). This research focuses on the security aspect of VoIP systems. Unsecured VoIP systems are vulnerable to malicious attacks. However, the overhead of the security techniques hampers the performance of VoIP systems. This research analyzes how a VoIP system performs with different security techniques. The performance of the VoIP system is analyzed on different types of data networks such as IPv4, IPv6, and IPv4/IPv6 mixed networks, and in scenarios such as with and without network traffic. Additionally, the research includes a cost-benefit analysis of the security techniques, to determine their cost effectiveness. Based on the performance analysis and cost-benefit analysis, this research proposes three security techniques that can be applied to VoIP systems deployed on IPv4, IPv6, and IPv4/IPv6 networks.