Selaus nimekkeen mukaan kokoelmassa Väitöskirjat
Aineistot 1-20 / 767
-
A comparative performance study of four-pole induction motors and synchronous reluctance motors in variable speed drives
Acta Universitatis LappeenrantaensisURN:ISSN:1456-4491 (25.06.2003)Design aspects of the Transversally Laminated Anisotropic (TLA) Synchronous Reluctance Motor (SynRM) are studied and the machine performance analysis compared to the Induction Motor (IM) is done. The SynRM rotor structure ... -
A holistic approach to measuring open innovation: contribution to theory development
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 24.05.2018)Since its introduction more than 10 years ago, open innovation (OI) has become a popular topic in the academic literature and has been accepted by many practitioners. The paradigm incorporates recent tendencies in economic ... -
A mathematical study of fuzzy logic; an algebraic approach
LTKK Tieteellisiä julkaisuja - Research PapersURN:ISSN:0356-8210 (1994)Fuzzy set theory and Fuzzy logic is studied from a mathematical point of view. The main goal is to investigatecommon mathematical structures in various fuzzy logical inference systems and to establish a general mathematical ... -
A modified nominal stress method for fatigue assessment of steel plates with thermally cut edges
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 18.12.2015)Thermal cutting methods, are commonly used in the manufacture of metal parts. Thermal cutting processes separate materials by using heat. The process can be done with or without a stream of cutting oxygen. Common processes ... -
A modified structural stress method for fatigue assessment of welded structures
Acta Universitatis LappeenrantaensisURN:ISSN:1456-4491 (08.12.2006)Fatigue life assessment of weldedstructures is commonly based on the nominal stress method, but more flexible and accurate methods have been introduced. In general, the assessment accuracy is improved as more localized ... -
A multimethod examination of contributors to successful on-the-job learning for vocational students
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 18.12.2014)Rapid changes in working life and competence requirements of different professions have increased interest in workplace learning. It is considered an effective way to learn and update professional skills by performing daily ... -
A novel approachfor assessing the fatigue strength of ultrasonic impact treated welded structures.
URN:ISSN:1456-4491 Acta Universitatis Lappeenrantaensis (18.12.2007)It is commonly observed that complex fabricated structures subject tofatigue loading fail at the welded joints. Some problems can be corrected by proper detail design but fatigue performance can also be improved using ... -
A novel procedure for establishing clinching parameters for high strength steel sheet
Acta Universitatis LappeenrantaensisURN:ISSN:1456-4491 (2000)The building industry has a particular interest in using clinching as a joining method for frame constructions of light-frame housing. Normally many clinch joints are required in joining of frames.In order to maximise the ... -
A Numerical Study of Forest Influences on the Atmospheric Boundary Layer and Wind Turbines
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 21.07.2017)In the past years, energy consumption in Finland was not fully covered by the energy produced in Finland, and approximately 20% of the total energy consumption was imported. Despite the suitable wind condition, the wind ... -
A Soft Contact Collision Method For Real-Time Simulation of Triangularized Geometries in Multibody Dynamics
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 27.05.2013)When modeling machines in their natural working environment collisions become a very important feature in terms of simulation accuracy. By expanding the simulation to include the operation environment, the need for a ... -
A study of combustion phenomena in circulating fluidized beds by developing and applying experimental and modelling methods for laboratory-scale reactors
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 22.12.2010)The results shown in this thesis are based on selected publications of the 2000s decade. The work was carried out in several national and EC funded public research projects and in close cooperation with industrial partners. ... -
A Study on Fractionation and Ultrafiltration of Proteins with Characterized Modified and Unmodified Membranes
LTKK Tieteellisiä julkaisuja - Research reportsURN:ISSN:0356-8210 (23.08.1996)Membrane filtration has become increasingly attractive in the processing of both foodand biotechnological products. However, the poor selectivity of the membranes and fouling are the critical factors limiting the development ... -
A Topological Approach to Fuzzy Sets
Acta Universitatis LappeenrantaensisURN:ISSN:1456-4491 (1999)This thesis presents a topological approach to studying fuzzy setsby means of modifier operators. Modifier operators are mathematical models, e.g., for hedges, and we present briefly different approaches to studying modifier ... -
Acidic dissolution of iron oxides and regeneration of a ceramic filter medium
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 14.12.2012)The dewatering of iron ore concentrates requires large capacity in addition to producing a cake with low moisture content. Such large processes are commonly energy intensive and means to lower the specific energy consumption ... -
Active du/dt Filtering for Variable-Speed AC Drives
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 17.12.2009)An oscillating overvoltage has become a common phenomenon at the motor terminal in inverter-fed variable-speed drives. The problem has emerged since modern insulated gate bipolar transistors have become the standard choice ... -
Active inverter output filtering methods
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 12.10.2012)Frequency converters are widely used in the industry to enable better controllability and efficiency of variable speed AC motor drives. Despite these advantages, certain challenges concerning the inverter and motor ... -
Active residential customer in a flexible energy system — a methodology to determine the customer behaviour in a multi-objective environment
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 05.12.2018)The transformation from passive into active end customers in modern energy systems has already started in many European countries, and it is a long process. The first step to engage residential customers to be active actors ... -
Actors in Sustainability Transitions
Acta Universitatis Lappeenrantaensis (Lappeenranta-Lahti University of Technology LUT, 26.04.2019)The world is experiencing serious sustainability challenges, such as climate change and the loss of biodiversity. To respond to these sustainability challenges, there is a need for societies throughout the world to make ... -
Adaptive Markov chain Monte Carlo and Bayesian filtering for state space models
Acta Universitatis Lappeenrantaensis (Lappeenranta University of Technology, 12.12.2014)This thesis is concerned with the state and parameter estimation in state space models. The estimation of states and parameters is an important task when mathematical modeling is applied to many different application areas ... -
Adaptive MCMC methods with applications in environmental and geophysical models
Finnish Meteorological Institute Contributions (Finnish Meteorological Institute, 14.03.2008)This work presents new, efficient Markov chain Monte Carlo (MCMC) simulation methods for statistical analysis in various modelling applications. When using MCMC methods, the model is simulated repeatedly to explore the ...
