Search for dissertations about: "frequency balance"

Showing result 1 - 5 of 97 swedish dissertations containing the words frequency balance.

  1. 1. Low frequency noise during work. Effects on performance and annoyance

    University dissertation from Göteborg

    Author : Johanna Bengtsson; Göteborgs universitet.; Gothenburg University.; [2003]
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Low frequency noise; performance; workload; annoyance; cortisol; subjective stress; subjective sensitivity to noise; sound characteristics; frequency balance; modulation frequency;

    Abstract : Aims. Low frequency noise (LFN) is defined as "a noise with a dominant frequency content of 20 to 200 Hz". Common sources of LFN in occupational environments are ventilation, heating and air-conditioning systems, computer network installations and compressors. READ MORE

  2. 2. Impaired balance and fall risk in people with multiple sclerosis

    University dissertation from Örebro : Örebro University

    Author : Anna Carling; Örebro universitet.; [2018]
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Balance; exercise; falls; falls efficacy; gait; multiple sclerosis; next of kin; physiotherapy; qualitative research; randomized controlled trial;

    Abstract : The symptoms from the neurological disease multiple sclerosis vary from person to person and over time. Impaired balance is common in people with multiple sclerosis and can lead to falls. Fall frequency is high in people with multiple sclerosis, above 50%. Multiple sclerosis affects not only the person having the disease but also their next of kin. READ MORE

  3. 3. Studies in Glacier Mass Balance Measurement and its errors

    University dissertation from Stockholm : Department of Physical Geography, Stockholm University

    Author : Andrew Mercer; Stockholms universitet.; [2018]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Glaciology; Mass Balance; Measurement Errors; naturgeografi; Physical Geography;

    Abstract : The study of the surface mass balance of valley glaciers has a long history but one that is dogged by uncertainty and errors, and uncertainty about those errors. These problems are acknowledged by the glaciological community and have been examined and formalised in several publications. READ MORE

  4. 4. Frequency Response by Wind Farms in Islanded Power Systems with High Wind Power Penetration

    University dissertation from Stockholm : Department of Physical Geography, Stockholm University

    Author : Mattias Persson; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Synthetic inertia; rate of change of frequency; inertia emulation; variable speed wind turbine; frequency control;

    Abstract : The integration of variable speed wind turbines (VSWT) in power systems keep increasing inorder to reduce the emission of green house gases. This increase of power electronic converterinterfaced generation causes a decrease of power system inertia and issues previously existingin power systems tend to become more complicated and new solutions should be evaluated. READ MORE

  5. 5. On Efficient Transmission Balancing Operation Capturing the Normal State Frequency and Active Power Dynamics

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Martin Nilsson; KTH.; [2018]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active Power Dynamics; Frequency Control; Normal State; Power System Balancing; Transmission System Operator; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In an electric power system, there will always be an electric balance. Nevertheless, System Operators (SOs) often uses the term imbalance. Here, the term imbalance refers to the difference between trades and real-time measurements. READ MORE