Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.

Since the spring 2003 the tenant-owner home association the Terrace in Upplands Väsby municipality lies straight under the approach route to Arlanda Airport?s new third landing chute. Noise levels of over 70 dB have been measured in the area, which exceeds National Board of Housing?s, values for traffic noise at a terrace in connection to housing. By using the method of hedonisk pricing the essay tries to find out if there exists a willingness to pay to reduce the noise in the area.

Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.

The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased Noise level from the engine when the afterburner is in use. The Noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero.

"Speak up! I can?t hear you"This qualitative study is built on an investigation of a newly instated model that is used when building or renovating schools. The principles of the model are based on building schools with an open plan design where the walls are made of glass and the classrooms are not shut closed by walls, instead the classrooms are completely open except from screens that are used to indicate the ambit of the rooms. This model has been well debated and that is the reason why we chose to do this study.The purpose of this study is to find out how students and teachers experience this model. To do this we have done interviews and observations.

In our everyday life we are constantly affected by sound; at home, on our way to and from work, when taking a walk through the woods and when we sleep. In discussions about sound one often talk about noise and to what degree a certain noise disturbs us. The positive qualities of a sound and what sounds contribute to the experience of a good environment is rarely discussed. The question of sound and the quality of sound is given more attention through the expansion of Stockholm, the city is becoming both bigger and more crowded. This raises new questions concerning the planning of the city e.g. should the changes of the sound quality in a place be one of the aspects taken into consideration when planning new buildings, are there ways to improve the sound quality in new building projects? Can we even improve the quality of sound in existing places by simple means? I have chosen to study four different areas in Stockholm; Hötorget, Mariatorget, Berzeliipark and Norrmalmstorg.

Noise is a growing health problem. People are not always aware of the injuries that noise can cause. The media culture of today has a big influence on teenagers. This is caused by portable music players, computers, concerts etc. The schools are having larg classes and that can cause a lot irrelevant speech during lessons.

Noise in schools can have negative effect on the teaching environment and speech perception. The national Child Environmental Health Surveys (BMHE) conducted in 2003 and 2011 studied how 12-year olds experience their sound environment in school. Results showed that the number of pupils that experience annoyance from noise increased from 2003 to 2011.Aim: The aim of this study was to study how 12-year olds perceive their sound environment in school.Methodology and material: A quantitative questionnaire survey was conducted in the sixth grade at two schools. The questionnaire used included questions from BMHE and self-produced questions. Sixtynine students answered the questionnaire.Results: Over 50 % of the respondents experience annoyance from noise in school several times a week.

NCC has given us a commission to investigate a planned housing area in Haga, Karlstad, situated close to the traffic route Hagaleden and the railway. The housing area consists of one hundred apartments in five different houses. The houses are linked to each other by balconies with glass panels. A long carport is situated between Hagaleden and the housing area to absorb part of the noise from the road. The design of the housing area is creating a silent backyard.

Landscape architecture is a visual profession, but other senses also affect our interpretation of a place. Sounds can give us a lot of information about an environment, and they are often perceived as positive. Despite this, research about outdoor sounds most often focus on the reduction of unwanted sounds ? noise ? but the absence of noise does not result in a good soundscape. To accomplish this, sounds we appreciate are needed.

In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology. Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch.

In recent years, existing solutions for cooling personal computer CPUs have been supplemented by a new product category, factory sealed water cooling loops. These systems, consisting of a water block with an integrated pump, a fan and a radiator, perform well compared to the air cooling solutions but are less effective than larger, custom-built water cooling systems.This project aims to explore the most important aspects of a factory sealed system and to identify possible cost-effective enhancements of the performance.The most significant differences between the different groups of water cooling loops are the block design and the pumping power. The performance of both categories is also largely dependent on the fan power, but increasing fan power has a large negative impact on the Noise level.Both radiator size and fan model choice appear, in tests, to be relatively unimportant, presuming that the Noise level is kept constant. The position and direction of the fan, however, has significant impact on both the temperature and the sound level.Water blocks can be designed in several different ways, both regarding the heatsink design and the flow direction. In simulation, flow with the inlet centered above the heatsink result in considerably lower pressure drop and slightly higher temperatures than flow through the block, for heatsinks with fin arrays.Creating a competitive product in this product segment certainly seems possible, as there are performance-increasing changes to be made that seemingly has little impact on the production cost.

During pre-slaughter handling of pigs the animals are often subjected to methods that induces stress and are a threat to the wellbeing of the animals, such as mixing of groups, loud noise and transportation. A new law will be implemented in 2006 in Sweden that prohibits mechanical noise exceeding 65 dB in abattoirs. The purpose of the research presented in this paper was to examine the effects of noise and transportation on pig behaviour. The activity and aggressiveness of the pigs were examined with behavioural studies during transportation and during three different Noise levels: 55, 75 and 95 dB. Before the noise treatments took place the groups were mixed and half of them were transported for approximately 2 hours. In the study 432 pigs were used.

The research within the management control systems-field and more specifically performance management has been rather shallow and not much has happened the last decades besides the balanced scorecard. The researchers see a lack of studies focusing on the effects of an integrated performance management system and also how it affects the different hierarchical levels and the tasks to perform.We decided to perform an essay with case study-characteristics by looking at both the strategic and tactical level at Volvo Group, or more specifically Group Trucks. We performed three different interviews, one at the group level and two at the division level. The aim was to see what effect an integrated performance management system had on the tactical level (i.e. the divisions).Our findings and corresponding analysis suggested that Volvo was a rather centralized company in order to get the performance management system to work by enabling a ?weekly control?.

There are a lot of different sounds in our sound saturated time. Noise is an unwishable soundand a high sound level can give short- or lingering problems for both children and adults.The purpose was to find out if and in that case why children and the activity at the pre-schoolaffects by a high soundlevel. Another purpose was to examine what the effects would be if thepedagogues set about the work to get a good sound environment at pre-school.The investigation was accomplished in shape of qualitative interwievs where six pedagoguesfrom different pre-schools answered questions about a high soundlevel.All of them have been educated to hearing pilotes.The result of this investigation shows that some pre-schools have a high sound levels but notall of them. In those cases where there is a high soundlevel are there often too many childrenat the same place on the same time. That makes the soundlevel even higher and both childrenand adults are getting tired.By improving the sound environment at the pre-school both children and adults often gets abetter activity.Keywords: high soundlevel, hearingpilot, noise, affects on children..