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245 Uppsatser om Acoustic signals - Sida 2 av 17

Passive acoustic diver detection

This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.

Hundens kommunikationssignaler

This literature study summarizes the signals dogs use in intraspecific communication. The purpose is to clarify the way dogs communicate so that situations where their intentions are misjudged can be avoided. The signals are divided into olfactory, visual, auditory and tactile and every section starts with a short anatomic and physiologic description of the sense organ that is used to register the current signal type. The interspecific communication between dog and human regarding its development and function is brought up. To end with suggestions are given of how veterinary technicians in clinics can make use of knowledge about the way dogs communicate.

Perceptuell och akustisk bedo?mning av ro?stfunktion hos barn med tonsillhypertrofi : Effekter av kirurgi

In Sweden over 10.000 patients annually, mostly children, undergo tonsillar surgery. The most common surgical method is total removal of the tonsil, tonsillectomy (TE). During the last decade partial tonsil resection, tonsillotomy (TT), has been reintroduced and is associated with lower primary morbidity and less postoperative pain. The aim of the present study was to evaluate if and to what extent 4-5 year old children?s voice function are affected by tonsillar hypertrophy compared to controls and to study the effects of the two surgical techniques on vocal function.

Ungdomars syn på kvalitet vid inköp av kläder

Teenagers are the group that spends most money on clothing. When choosing clothes, the so called internal and external signals could affect the perceived quality of the teenagers. The external signals are for example price, brand and place of purchase while the internal signals are the physical composition of the product as for example garment and size. The perceived quality is the attributes that the teenagers perceive that the specific article of clothing has. Today?s marketing, within the fashion line, is mostly to present the design of the product and aim the marketing for curtain segments and to keep a distance to others that are not within the segment group.

Spelar tarmcellernas interna fettförbränning en roll i regleringen av födointag?

Since several lifestyle diseases are associated with obesity much research is carried out within the area. Researchers have found that oxidation of fatty acids within the body?s cells may give rise to peripheral signals which regulate food intake, but it is still unclear where such a mechanism takes place. Although much evidence suggests that it is the hepatocytes in the liver that send signals regulating food intake, some researchers have begun to question this theory. Instead they argue that the mechanism takes place within the enterocytes since they are well localised in the gut for such assignment.

Att identifiera signaler för obestånd i tid

To be able to protect themselves from credit risk, the banks must constantly check the performance of  the companies they have lent money to. There are many mathematical models for predicting financial distress. These models use accounting-based ratios, which often are historical and not representative for the present situation. This study describes how the banks do in practice to find signals of insolvency in time and the variables they are observing for doing that.In addition to financial reports which the company sends in to the bank at least once a year, also the relationship between them and information from different information  agencies are of great importance to track  signals of insolvency. Poor profitability is the primary cause of insolvency.

Undersökning av optimeringsalternativ för elektrostatlackering

This report describes a thesis done at the Jönköping University of Technology. The aim of this thesis was to create conditions to optimize an existing automatic electrostatic coating system by changing the technology for dispensing lacquer. To select the technology, a study of different dispensing techniques carried out which concluded that the piezoelectric membrane and electrostatic atomization are the most interesting techniques.In order to perform tests with dispensing techniques a demonstrator has been optimized. The controller and PC software of the demonstrator has been programmed to be able to send out PWM signals that control the dispensers. An adapter card was designed to control the piezoelectric membrane and a steering link to the electrostatic atomization has been developed for PWM signals up to 500V.The work has laid ground for a demonstrator where further testing of the dispensing technologies can be performed..

Ström- och temperaturkontroll

Storing kinetic energy in a flywheel allows for more efficient driving of electricvehicles. Research in this area is in progress at Uppsala University, where a flywheelwith magnetic bearings encased in a vacuum chamber is being constructed. To makethis possible methods for measuring the current through the electromagnets in thebearings and temperatures in the flywheel need to be developed. This has been thepurpose of this report. The current measurement resulted in a resistive method, andthe implementation of eight measurement circuits in the system.

Automatisk mätning och detektering av röjande signaler

This master thesis has been performed at Sectra Communications AB in Linköping where they manufacture electronic encryption devices. In cryptology it is essential that an eavesdropper cannot find the plain text. To assure that a system is safe, all devices are thoroughly examined so that they don?t emit any secret information, so called Compromising Emanations (CE). This is done by comparing the secret signal with measured signals on the screen of an oscilloscope, a process that is very time consuming and furthermore, the risk of missing compromising emanations is high.

Mätning av dynamiskt tryck med piezoresistiva tryckgivare på roterande objekt

The report handles the transmission of signals from piezoresistive pressuresensors and thermocouple from a rotating object. This report also evaluates the possibility to collect data in a datalogger that rotates with the object. Telemetrics was previously used for signaltransmission in Finspång, therefore there has been no tests considering preassure measuring. One transmitting method handled in this report is transmission through a slipring connection. One test with a slipring connection was performed for transmitting signals from a piezoresistive preassuresensor.

Åtgärder för att minimera trafikbullers påverkan på ett rekreationsområde

The aim of this inquiry was to investigate the most appropriate measures to reduce noise impacts from road traffic on the Nydala recreational area in Umeå municipality due to the planned re-routing of the E4 motorway to an existing road along this area. The sound environment is an important part in the experience when we are visiting recreational areas. Noise is not only disturbing; the liberty from unwanted sounds also allows us to perceive natural sounds that are a benefit for the cultural experience. Therefore it is important to take actions to protect this well used area from traffic noise. The reasonable options to avoid noise impact in this case are to lower the speed limit, using a noise reducing coating or use noise protection screens and walls.

Social struktur och dominans hos hund

The dog (Canis lupus familiaris) is the first species ever domesticated. They can develop a close bond towards other dogs, almost like a relationship among siblings, which can be a high valuable resource for good relations and cooperation?s. Dominance in dogs is sometimes used to explain undesired behaviors and explained as a personality trait. Dominance though, is not a trait in a dog or a source for undesired behaviors, but can rather be explained as a relationship between individuals, were one of them receives more submissive signals from the other.

Tidssynkroniserade mätningar i vattenkraftstationer

Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP.

The control of the cell cycle with particular emphasis on the G1/S transition

Tumour development occurs to a large extent because of dysregulation of the cell cycle. Of particular importance are defects occurring in the G1 phase. The reason why G1 is critical is because of the influence of several signals (external signals as well as cyclins and cdks) on this stage. The G1 phase can be divided into two parts, G1pm and G1ps. Each part has its ?own? restriction point which needs to be passed in order to progress to S phase.

Samspelseffekter vid kapacitetsförbättringar. : Exempel från Dalabanan.

The trend in the transport sector is moving towards eco-friendly, fast and convenient transportation,this results in higher demands on railway transports. To meet the demand and quality requirements,the Swedish railway network will have to expand. The cheapest way is to expand little by little butwhat impact do these small steps actually have on the capacity?This thesis examines the interactions of different improvement for the capacity on a single-trackrailway. Through simulations in the software tool RailSys this report studies what effect block signals,extra meeting stations and rebuilding existing two track passing loops to three track loops have onthe capacity.

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