Search results for "systems"

Applications of tunnel junctions in low-dimensional nanostructures

2009

This thesis concentrates on studies of AlOx based tunnel junctions and their feasibility for cooling, thermometry and strain sensing in suspended nanostructures. The main result of the thesis is cooling of one dimensional phonon modes of a suspended nanowire with normal metal insulator superconductor (NIS) tunnel junctions. Simultaneous cooling of both electrons and phonons was achieved, and the lowest phonon temperature reached in the system was 42 mK with an initial temperature of 100 mK. In addition, suspended devices show cooling still at a bath temperature of 600 mK. The observed thermal transport characteristics show, that the heat flow is limited by the scattering of phonons at the b…

Formation structure of optimality by thermoeconomics: disassembling thermodynamic and external influences in energy systems’ design

2009

In this paper an original thermoeconomic approach for the optimization of complex energy systems is presented, based on a revitalized concept of “scope”, and therefore indicated as Scope Oriented Thermoeconomics (SOT). In plants including dissipative components, it allows to formulate non-arbitrary allocation criteria as concerns marginal costs; consequently, the optimization process is disassembled to recognize the Formation Structure of Optimality, i.e. the specific influences of thermodynamic and economic parameters in the path toward the optimal design. The method is applied to a very didascalic example, that is the optimization of the condensation temperature in a vapour compression ch…

Investigation of Nonlinear Optical Processes in Mercury Sulfide Quantum Dots

2022

European Regional Development Fund (1.1.1.5/19/A/003), State Assignment to Higher Educational Institutions of Russian Federation (FZGU-2020-0035), Russian Foundation for Basic Research (18-29-20062). Institute of Solid State Physics, University of Latvia as the Center of Excellence acknowledges funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.

Implementation of IUCN criteria for the definition of the Red List of Ecosystems in Italy, Plant Biosystems.

2020

The present work is aimed at presenting the data, methods and criteria that are being used for the assessment of ecosystem collapse risk in Italy.

Overview of Power Electronic Switches: A Summary of the Past, State-of-the-Art and Illumination of the Future.

2020

As the need for green and effective utilization of energy continues to grow, the advancements in the energy and power electronics industry are constantly driven by this need, as both industries are intertwined for obvious reasons. The developments in the power electronics industry has over the years hinged on the progress of the semiconductor device industry. The semiconductor device industry could be said to be on the edge of a turn into a new era, a paradigm shift from the conventional silicon devices to the wide band gap semiconductor technologies. While a lot of work is being done in research and manufacturing sectors, it is important to look back at the past, evaluate the current progr…

The building blocks of academic writing in the field of information systems

2018

Tieto, valta ja vastuu erityislasten hoidossa

2016

Artikkelissa tarkastelen sitä, kuinka erityislasten vanhempien tieto ja asiantuntemus lasta koskevissa asioissa rakentuu ja kuinka siihen suhtaudutaan auttamistyön tilanteissa. Aineistoni koostuu vanhempien kokemuskertomuksista, joissa he kuvaavat erityislapsen vanhemmuuteen kasvua sekä kohtaamisia ammattilaisten kanssa auttamistyön kentillä. Tutkimukseni rakentaa kuvan epäsymmetriselle vallalle perustuvasta vuorovaikutuksesta, jossa ammattilaisen ja asiakkaan roolia määrittelevät kulttuuriset kategoriat vaikuttavat vanhempien mahdollisuuksiin osallistua auttamistyön neuvotteluihin. Näiden kategorioiden mukaan asiakkaan roolina on olla tiedon ja avun vastaanottaja, minkä seurauksena heidän …

Applying Semiautomatic Generation of Conceptual Models to Decision Support Systems Domain

2009

This paper presents a decision support system specification in the form of business use cases and a stereotyped conceptual model based on the specification. The use cases are based on generic user requirements and address cognitive biases. The specification can be used to set fixed and common terms among the project participants. Semiautomatic generation of the conceptual model is demonstrated with mixed results. While there are some shortcomings in the parsing and the result is dependent on the phrasing conventions used in the use cases, the conceptual model highlights the most essential entities in the domain and provides a base for further development phases. peerReviewed

A Study on the Assessment of Introductory Computational Thinking via Scratch Programming in Primary Schools

2018

Computational thinking (CT), a transversal intellectual foundation integral to computer science, is making its way into compulsory comprehensive education worldwide. Students are expected to attain skills and knowledge in such interdisciplinary CT principles as Algorithmic thinking, Data representation, and Debugging. Problem-solving by designing and manipulating interactive media with Scratch, a graphical programming tool, is popular especially at the primary school level. However, there has been confusion regarding how introductory CT can be operationalized for educational practice. Teachers and students need research-based knowledge for setting appropriate learning goals in addition to i…

Estimation of the Time-Variant Velocity of a Single Walking Person in Two-Dimensional Non-Stationary Indoor Environments Using Radio-Frequency Techni…

2020

Accurate estimation of the time-variant (TV) velocity of moving persons/objects in indoor spaces is of crucial importance for numerous wireless indoor applications. This article introduces a novel iterative procedure to estimate the TV velocity, i.e., TV speed and TV angle-of-motion (AOM), of a single moving person in 2D indoor environments by using radio-frequency (RF) techniques. The indoor area is equipped with a distributed 2 × 2 multiple-input multiple-output (MIMO) system. The proposed method is divided into two parts. In the first part, we estimate the path gains and the instantaneous Doppler frequencies by fitting the exact spectrograms of the complex channel gains of a 2D no…