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3743 Uppsatser om Noise level - Sida 3 av 250

Går det att säkerställa ljudmiljön i en träningslokal? - en studie om ljudnivåövervakare på träningslokaler i Göteborg

In Sweden, exercise takes a great part in people?s lives. Health and a good conditioned body go hand in hand. Many Swedes exercise in groups, with aerobics or a similar form of workout at a training facility. A regular workout lasts for about an hour and is accompanied by music.

Dämpning av ljud i Shift-by-Wire växelväljare : Noise damping in a Shift-by-Wire gear shifter

Constantly growing demands from the costumers in the Automotive industry forces the subcontractors to seek alternative ways to compete. One parameter of quality is the components tolerance against NVH(Noise, Vibraion & Harshness) aspects. Kongsbergs Automotive has developed a new gear shifter platform (Shift-by-Wire) that is sold to Alfa Romeo and used in of their car models. However, the company is not pleased with the components sound quality, therefore the main purpose of this thesis is to develope a number of concepts that is supposed to enhance these NVH-aspects.To get an understanding of the problem an analysis of the causes of the emitted sound has been done parallell to a product decomposition, function decomposition and a Ishikawa-diagram. Together with these methods has a litterature study been performed to get familiar with the physics of an impact and especially the emittment of noise.

MÄTNING AV LJUDIMMISSION FRÅN VINDKRAFT. VIDAREUTVECKLING AV METOD FÖR MÄTNING

The Swedish government have a goal that wind turbines shall produce 30 TWh by the year 2020, compared to about 3,5 TWh produced in Sweden during 2010. To minimize the disturbance that wind turbines create the Swedish Environmental Protection Agency has stated a guideline value that noise from wind turbines at nearby residents shouldn?t exceed 40 dBA, at 8 m/s wind speed. With advanced calculation models, like Nord 2000, the emitted sound from future wind turbines can be calculated at an early stage to optimize the power production without exceeding the 40 dBA. When the turbines have been built there is a need to verify that they really are within the guideline.

Design och tillverkning av en stereoanläggning med aktivt delningsfilter

This thesis is the result of the author?s interest in music and electronics, namely the design and manufacturing of a stereo sound system with an active crossover. In short it can be stated that an active crossover has many advantages over its traditional passive counterpart. The active design naturally results in a more complex system comprised of a multiple number of components. This report deals with the theoretical aspects of preamplifiers, crossovers and power amplifiers as well as power supply and control.

Strömkontroll till aktiva magnetlager med noggrann och störningsreducerad strömmätning

There is always a need for more effective ways to store energy in order to reduce the human impact on the environment. One step on the way can be the use of flywheels as kinetic energy storage devices. Low frictional losses are essential for a flywheel to be effective. To minimize these losses active magnetic bearings (AMB) can be used to keep the shaft centered instead of the more conventional ball-bearings. AMBs use actuators and a fast control system that needs correct and noise-free measurement data of the shaft position and the current in the actuators to work properly.This thesis explains the process of constructing power electronics and a current measurement system for active magnetic bearings (AMB).

Bilar eller blåmesar? : rehabiliteringsvärdet i Umeås tätortsnära skogar

Nature´s healing capacity is well known and is today an important asset in the protection against stress. Noise problems in cities and it´s green spaces are increasing which in turn provokes stress and in the long term can lead to cardiovascular diseases. To promote people?s health it is important that natural environments have good soundscapes, research show that visiting natural surroundings and listening to sounds of nature promote rehabilitation and relief stress. The purpose of this essay is to determine the value of rehabilitation in forests in Carlshem and Röbäck.

Läsflöde eller läsmöda? : Ett arbete om hur la?sning pa?verkas (och inte pa?verkas) av olika element pa? en webbplats fo?rstasida.

The purpose of this project was to find out how reading is affected, and not affected, by different elements on a start page. The site I was studied belongs to the magazine Fitness Magazine, and the current site has a problem. The editorial texts and articles don?t reach out to the visitors. The goal was to make a proposal for a new first page of the web site that highlights the texts and the reading.With the help of interviews, user testing and textual analysis, I studied if the texts were in itself that caused the problem or if it was the design.

Filter och kapsling för IR-givare

This paper describes the work done trying to diminish the noise present in the signal from an IR-detector. The project was aiming towards two different kinds of applications; heat protection and presence detection. The hypothesis was that the signal-noise ratio would decrease if a filter and a proper installation were used for the detector. Some experiments were executed to determine what kind of filter were the most suitable for each application and how these could be installed. After executing the experiments and evaluate the results we recommend to use a specific filter for each application.

Hörapparatnyttan hos dem som ordinerats hörapparat med öppen anpassning ? En utvärdering

An open fitting is suitable for persons with sloping hearing loss and relatively good low fre-quency hearing. Sensory neural hearing losses often have this type of configuration. A large ventilation canal gives a greater feeling of comfort and less occlusion. The purpose of this study was to look at the hearing aid benefit of open fitted hearing aids. Self report question-naires were sent out to 102 patients who were given ReSound AIR during the year of 2006 in Uddevalla.

Bullrets omfattning och inverkan på sjukhusmiljö

Syftet med litteraturstudien var att undersöka hur buller påverkar sjukhusmiljön med hänseende på vårdpersonal och patienter. Studiens avsikt omfattar även en undersökning av vårdpersonalens och patienters eventuella olika uppfattningar angående buller. Effekterna av buller och dess omfattning inom vårdavdelningsmiljön har också undersökts. Resultatet av studien visar på att bullermiljön på sjukhus överskrider de riktlinjer för buller som WHO fastslagit. Vidare visar studien på indikationer på att brittiska sjuksköterskors kunskap angående fenomenet buller är bristfällig.

Hur påverkar byggnadsmaterial av stål en induktiv hörslingas fältstyrka samt frekvensgång?

This research analyzed differences in measurements of magnetic field strength and frequency response in five audio induction loops installed in rooms of wooden construction materials and five audio inductive loops installed in rooms of steel reinforced concrete constructions. The inductive loops were installed at floor level and the measurements were made at the listening height of 1.2m. Measurements of background noise, field strength and frequency response were made at fifteen different measurement points across the room. The research measurements showed that there are differences in field strength and frequency response between these two conditions, whether the audio induction loop is installed in a wooden construction or the audio induction loop is installed in a reinforced concrete construction. The results had a significance level of p=0,05..

BIM i förvaltningsskedet - Nyttan för fastighetsägare

The use of Power Line Communication, PLC, as a communication solution for Automated Meter Reading, AMR, is popular by utilities in Sweden and other parts of the world due to demands of accurate and fast meter reading. However the use of the electrical grid as a communication medium is complex and sometimes problematic. This report handles some of the issues and problems that are important to understand when using the grid as a communications medium. Focus is mainly on investigating high frequency distortion in the Kristianstad power grid own by C4energi caused by a frequency converter. Measurements on site are done to investigate signal damping in the grid, different configurations for the frequency converter and signal strength of the PLC-system.

Att projektera för demontering. Undersökning av stomsystem

The use of Power Line Communication, PLC, as a communication solution for Automated Meter Reading, AMR, is popular by utilities in Sweden and other parts of the world due to demands of accurate and fast meter reading. However the use of the electrical grid as a communication medium is complex and sometimes problematic. This report handles some of the issues and problems that are important to understand when using the grid as a communications medium. Focus is mainly on investigating high frequency distortion in the Kristianstad power grid own by C4energi caused by a frequency converter. Measurements on site are done to investigate signal damping in the grid, different configurations for the frequency converter and signal strength of the PLC-system.

Analys av högfrekvensstörningar och elnätskommunikation i distributionsnät

The use of Power Line Communication, PLC, as a communication solution for Automated Meter Reading, AMR, is popular by utilities in Sweden and other parts of the world due to demands of accurate and fast meter reading. However the use of the electrical grid as a communication medium is complex and sometimes problematic. This report handles some of the issues and problems that are important to understand when using the grid as a communications medium. Focus is mainly on investigating high frequency distortion in the Kristianstad power grid own by C4energi caused by a frequency converter. Measurements on site are done to investigate signal damping in the grid, different configurations for the frequency converter and signal strength of the PLC-system.

Undersökning av lönsamhet inför fastighetsförvärv

The use of Power Line Communication, PLC, as a communication solution for Automated Meter Reading, AMR, is popular by utilities in Sweden and other parts of the world due to demands of accurate and fast meter reading. However the use of the electrical grid as a communication medium is complex and sometimes problematic. This report handles some of the issues and problems that are important to understand when using the grid as a communications medium. Focus is mainly on investigating high frequency distortion in the Kristianstad power grid own by C4energi caused by a frequency converter. Measurements on site are done to investigate signal damping in the grid, different configurations for the frequency converter and signal strength of the PLC-system.

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