PCIExpress Communication Layer for ATCA-based Linear Accelerator Control System

PCIExpress architecture is widely used communication bus designed, among other things, for industrial application. Additionally, according to PICMG 3.4 specification it is part of an ATCA architecture. For that reason PCIExpress was used as communication interface for data transmission between ATCA carrier boards and AMC modules for the new control system for XFEL linear accelerator. In this paper authors present general overview of this system, describe communication protocols designed to exchange data with external user application and show results of performance test

Fixed points of nonnegative neural networks

We consider the existence of fixed points of nonnegative neural networks, i.e., neural networks that take as an input and produce as an output nonnegative vectors. We first show that nonnegative neural networks with nonnegative weights and biases can be recognized as monotonic and (weakly) scalable functions within the framework of nonlinear Perron-Frobenius theory. This fact enables us to provide conditions for the existence of fixed points of nonnegative neural networks, and these conditions are weaker than those obtained recently using arguments in convex analysis. Furthermore, we prove that the shape of the fixed point set of nonnegative neural networks with nonnegative weights and biases is an interval, which under mild conditions degenerates to a point. These results are then used to obtain the existence of fixed points of more general types of nonnegative neural networks. The results of this paper contribute to the understanding of the behavior of autoencoders, and they provide insight into neural networks designed using the loop-unrolling technique, which can be seen as a fixed point searching algorithm. The chief theoretical results of this paper are verified in numerical simulations.Comment: 34 page

Reconstructing stakeholder relationships using ‘corporate social responsibility’ as a response strategy to cases of corporate irresponsibility: The case of the 2010 BP spill in the Gulf of Mexico.

Purpose When organisations behave irresponsibly, a question remains: Can they use a messaging strategy based in the organisation’s commitment social responsibility to effectively respond to the crisis? The purpose of this chapter is to analyse stakeholder attitudes and their antecedents in such a case. Because of its scope, magnitude and use of a response strategy based on messages of social responsibility, the 2010 BP oil spill in the Gulf of Mexico serves as an excellent case for measuring the effectiveness of such a messaging strategy. Methodology/approach The present study drew from two data sources: a content analysis of interactions on BP’s Facebook page (N=1,515) as well as an image survey of BP (N=749). Findings BP’s messaging strategy had limited positive effects in terms of (1) being viewed as a ‘socially responsible’ organisation and (2) creating significant good will towards the company. However, these data also reveal that BP has effectively opened lines of communication between stakeholders and the company. Practical and social implications This study has two central implications. First, for both organisations and activists, personal investment and the relevance of issues are both critical in order to change stakeholder attitudes about organisations. Second, based on this research, we can begin to develop stakeholder profiles based on age, sex and political identity. Originality/value In the last couple of years, considerable attention has been paid to describing and analysing the response strategies that organisations deploy; however, scant attention has been paid to measuring stakeholder evaluations of those crisis response strategies

Inverse Solvability and Security with Applications to Federated Learning

We introduce the concepts of inverse solvability and security for a generic linear forward model and demonstrate how they can be applied to models used in federated learning. We provide examples of such models which differ in the resulting inverse solvability and security as defined in this paper. We also show how the large number of users participating in a given iteration of federated learning can be leveraged to increase both solvability and security. Finally, we discuss possible extensions of the presented concepts including the nonlinear case

Multipurpose electric furnace system

A multipurpose electric furnace system of advanced design for space applications was developed and tested. This system is intended for use in the Apollo-Soyuz Test Program. It consists of the furnace, control package and a helium package for rapid cooldown