Search results for "avaruus"

0.1-10 MeV Neutron Soft Error Rate in Accelerator and Atmospheric Environments

2021

Neutrons with energies between 0.1-10 MeV can significantly impact the Soft Error Rate (SER) in SRAMs manufactured in scaled technologies, with respect to high-energy neutrons. Their contribution is evaluated in accelerator, ground level and avionic (12 km of altitude) environments. Experimental cross sections were measured with monoenergetic neutrons from 144 keV to 17 MeV, and results benchmarked with Monte Carlo simulations. It was found that even 144 keV neutrons can induce upsets due to elastic scattering. Moreover, neutrons in the 0.1-10 MeV energy range can induce more than 60% of the overall upset rate in accelerator applications, while their contribution can exceed 18% in avionics.…

Assessment of Proton Direct Ionization for the Radiation Hardness Assurance of Deep Submicron SRAMs Used in Space Applications

2021

Proton direct ionization from low-energy protons has been shown to have a potentially significant impact on the accuracy of prediction methods used to calculate the upset rates of memory devices in space applications for state-of-the-art deep sub-micron technologies. The general approach nowadays is to consider a safety margin to apply over the upset rate computed from high-energy proton and heavy ion experimental data. The data reported here present a challenge to this approach. Different upset rate prediction methods are used and compared in order to establish the impact of proton direct ionization on the total upset rate. No matter the method employed the findings suggest that proton dir…

Paratiisimyytti Toivo Pekkasen Mustassa hurmiossa ja Antti Tuurin Maan avaruudessa

2007

Weighted Hardy inequalities beyond Lipschitz domains

2014

It is a well-known fact that in a Lipschitz domain \Omega\subset R^n a p-Hardy inequality, with weight d(x,\partial\Omega)^\beta, holds for all u\in C_0^\infty(\Omega) whenever \beta<p-1. We show that actually the same is true under the sole assumption that the boundary of the domain satisfies a uniform density condition with the exponent \lambda=n-1. Corresponding results also hold for smaller exponents, and, in fact, our methods work in general metric spaces satisfying standard structural assumptions.

Self-improvement of weighted pointwise inequalities on open sets

2020

We prove a general self-improvement property for a family of weighted pointwise inequalities on open sets, including pointwise Hardy inequalities with distance weights. For this purpose we introduce and study the classes of $p$-Poincar\'e and $p$-Hardy weights for an open set $\Omega\subset X$, where $X$ is a metric measure space. We also apply the self-improvement of weighted pointwise Hardy inequalities in connection with usual integral versions of Hardy inequalities.

Riemann surfaces and Teichmüller theory

2017

Riemannin pinnat ja Teichmüller-teoriaa. Tämän työn päämääränä on määritellä Riemannin pintojen Teichmüller-avaruudet sekä tutkia niiden geometrisia ominaisuuksia. Ensin työssä kehitetään peiteavaruuksien ja toimintojen teoriaa, jota sovelletaan Möbius-kuvauksista koostuviin ryhmiin. Tämän jälkeen kvasikonformaalikuvaukset määritellään Riemannin pinnoille ja niiden yhteyttä yhdesti yhtenäisten Riemannin avaruuksien kvasikonformikuvauksiin tutkitaan. Näitä tietoja sekä yhdesti yhtenäisten Riemannin pintojen uniformisaatiolausetta hyödyntämällä todistetaan yleisten Riemannin pintojen uniformisaatiolause. Tämä tulos liittää pinnat Möbius-kuvauksien toimintoihin yhdesti yhtenäisillä Riemannin p…

Radiation Hardness Assurance Through System-Level Testing: Risk Acceptance, Facility Requirements, Test Methodology, and Data Exploitation

2021

International audience; Functional verification schemes at a level different from component-level testing are emerging as a cost-effective tool for those space systems for which the risk associated with a lower level of assurance can be accepted. Despite the promising potential, system-level radiation testing can be applied to the functional verification of systems under restricted intrinsic boundaries. Most of them are related to the use of hadrons as opposed to heavy ions. Hadrons are preferred for the irradiation of any bulky system, in general, because of their deeper penetration capabilities. General guidelines about the test preparation and procedure for a high-level radiation test ar…

bssm: Bayesian Inference of Non-linear and Non-Gaussian State Space Models in R

2021

We present an R package bssm for Bayesian non-linear/non-Gaussian state space modelling. Unlike the existing packages, bssm allows for easy-to-use approximate inference based on Gaussian approximations such as the Laplace approximation and the extended Kalman filter. The package accommodates also discretely observed latent diffusion processes. The inference is based on fully automatic, adaptive Markov chain Monte Carlo (MCMC) on the hyperparameters, with optional importance sampling post-correction to eliminate any approximation bias. The package implements also a direct pseudo-marginal MCMC and a delayed acceptance pseudo-marginal MCMC using intermediate approximations. The package offers …

Rhizomatic Target Audiences of the Cyber Domain

2016

Target Audience Analysis (TAA) is a process of finding suitable target audiences for psychological operations (PSYOPS). Typically, a TAA is a one-way process with some kind of a feedback system. The cyber domain presents a challenge to this type of sequential, linear process by refusing to stay still while the process is being executed, possibly leading to results from yesterday’s data in an environment that no longer exists today. Another challenge is that identifiable human beings—the traditional targets of PSYOPS—are not the only inhabitants of the cyber domain. Physical devices, nicknames, IP addresses, networks, and a vast amount of data populate this environment, in which there are no…

Cyber warfare : the game changer in the battlespace

2022

A recent development in warfare has been the integration of Electronic Warfare (EW), Information Warfare (IW) and Cyber Warfare (CW) systems designed to generate non-kinetic effects in battle space together with the traditional use of kinetic weapons. These new capacities of armed forces create new possibilities to achieve the goals of war. These advanced and new capabilities form a whole new non-kinetic environment in which they have become a game changer in battle space. This article focuses on describing cyber warfare and the first experiences of the war in Ukraine. nonPeerReviewed