Zobrazeno 1 - 10
of 6 141
pro vyhledávání: '"Valkonen, A."'
Autor:
Dizon, Neil, Valkonen, Tuomo
With a view on bilevel and PDE-constrained optimisation, we develop iterative estimates $\widetilde{F'}(x^k)$ of $F'(x^k)$ for compositions $F :=J \circ S$, where $S$ is the solution mapping of the inner optimisation problem or PDE. The idea is to fo
Externí odkaz:
http://arxiv.org/abs/2412.01481
Autor:
Suonperä, Ensio, Valkonen, Tuomo
Bilevel optimisation is used in inverse problems for hyperparameter learning and experimental design. For instance, it can be used to find optimal regularisation parameters and forward operators, based on a set of training pairs. However, computation
Externí odkaz:
http://arxiv.org/abs/2408.08123
In this study, we elaborate on the concept of scalable anomalous reflector (AR) to analyze the angular response, frequency response, and spatial scalability of a designed AR across a broad range of angles and frequencies. We utilize theoretical model
Externí odkaz:
http://arxiv.org/abs/2407.17279
Online optimisation facilitates the solution of dynamic inverse problems, such as image stabilisation, fluid flow monitoring, and dynamic medical imaging. In this paper, we improve upon previous work on predictive online primal-dual methods on two fr
Externí odkaz:
http://arxiv.org/abs/2405.02497
Autor:
Nurmi, Juha, Paju, Arttu, Brumley, Billy Bob, Insoll, Tegan, Ovaska, Anna K., Soloveva, Valeriia, Vaaranen-Valkonen, Nina, Aaltonen, Mikko, Arroyo, David
Publikováno v:
Scientific Reports 14, 7849 (2024)
Tor is widely used for staying anonymous online and accessing onion websites; unfortunately, Tor is popular for distributing and viewing illicit child sexual abuse material (CSAM). From 2018 to 2023, we analyse 176,683 onion domains and find that one
Externí odkaz:
http://arxiv.org/abs/2404.14112
Autor:
Hao, Le, Vuyyuru, Sravan K. R., Tretyakov, Sergei A., Salihu, Artan, Rupp, Markus, Valkonen, Risto
In this paper, we systematically study the electromagnetic (EM) and communication aspects of an RIS through EM simulations, system-level and ray-tracing simulations, and finally measurements. We simulate a nearly perfect, lossless RIS, and a realisti
Externí odkaz:
http://arxiv.org/abs/2403.13210
This work aims to build connections between the electromagnetic and communication aspects of Reconfigurable Intelligent Surfaces (RIS) by proposing a methodology to combine outputs from electromagnetic RIS design into an RIS-tailored system-level sim
Externí odkaz:
http://arxiv.org/abs/2403.12790
A design methodology for planar loaded antenna arrays is proposed to synthesize a perfect anomalous reflection into an arbitrary direction by optimizing the scattering characteristics of passively loaded array antennas. It is based on efficient and a
Externí odkaz:
http://arxiv.org/abs/2312.04441
Publikováno v:
BMC Public Health, Vol 24, Iss 1, Pp 1-12 (2024)
Abstract Background Suicidal persons’ contacts with services present a key opportunity for suicide prevention. However, interventions by services are not always effective. A deeper understanding of suicidal service users’ agency and its implicati
Externí odkaz:
https://doaj.org/article/70a72912a0474a79a99d6f46a92fc3e6
Autor:
Janos Wasternack, Hendrik V. Schröder, J. Felix Witte, Mihkel Ilisson, Henrik Hupatz, Julian F. Hille, Marius Gaedke, Arto M. Valkonen, Sebastian Sobottka, Alexander Krappe, Mario Schubert, Beate Paulus, Kari Rissanen, Biprajit Sarkar, Siegfried Eigler, Ute Resch-Genger, Christoph A. Schalley
Publikováno v:
Communications Chemistry, Vol 7, Iss 1, Pp 1-11 (2024)
Abstract In nature, molecular environments in proteins can sterically protect and stabilize reactive species such as organic radicals through non-covalent interactions. Here, we report a near-infrared fluorescent rotaxane in which the stabilization o
Externí odkaz:
https://doaj.org/article/232d32d3b189456694ae2f1096b1f121