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777 Uppsatser om Intermediate frequency - Sida 5 av 52
Design of a Direct-conversion Radio Receiver Front-end in CMOS Technology
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.
Hjärtfrekvensvariabilitet hos friska hundar
In healthy dogs, heart rate fluctuates during the day. Heart rate variability (HRV) reflects the autonomic nervous system´s regulation of the cardiovascular unit. Heart rate variability shows the balance between the sympathetic and parasympathetic nervous system, also called sympathovagal balance. Heart rate variability can be measured by time domain - and frequency domain analysis. In a time domain analysis you study the beat-to-beat-interval (RR-interval) in an electrocardiogram (ECG), while a frequency domain analysis can be used to determine the size of the variability.
Design och implementering av enhandsburen RFID-läsare
Radio frequency identification (RFID) is a versatile wireless technology usedworldwide. The fields of applications are many and its popularity constantlygrows due to smaller in size, better and less expensive components. RFID isused to identify, track or share information about an object using radio waves.This master thesis describes the process of designing and implementing ahandheld UHF RFID reader. The goal was to, based on a UHF RFID-chipdesign a fully functional, small in size and power efficient device. Amicrocontroller provides the user interface and is also used to control theRFID-chip and a Bluetooth device.
Passage Retrieval en studie av index
The aim with this thesis came out of a strong interest for Passage Retrieval. Our intention has not been to evaluate an IR-system. Instead our goal has been to analyze the result of indexing documents and their passages. We have been studying the weights of the different terms in the different indices, in comparison with other parameters like frequency, normalized frequency and the inversed document frequency. Further more we have been looking at how the weights are spread using for instance the standard deviation.
Gränssnitt, användbarhet och sökmotorer: ett experiment
This aim of this thesis is to measure the effect of the user interface in real searches on the Internet through a small experiment. Theories on web and search usability and psychological factors concerning usability were first explored. Then three interfaces were constructed, one "good" that followed usability guidelines and had multiple search functions, one "bad" that completely disobeyed those guidelines and had only a simple and small search field, and one "intermediate" interface that was a mix of the two. The search field was set to different sizes, with the shortest in the "bad" interface, a medium field in the "intermediate" interface and several long fields in the "good" interface. All three interfaces were then attached to the same web search engine, Altavista.
Variation in frequency of alleles in the MTNR1A gene with possible impact on ability of ewes to show oestrus out of season
In Swedish sheep industry it is desired to have lambs slaughtered evenly distributed over the year. Swedish sheep are generally seasonal breeders with lambs born in the spring and slaughtered in the autumn. Some of the breeds, e.g. Swedish Finewool and Roslag sheep breeds have shown ability to lamb out of season. For increased knowledge on the possibilities to breed for out-of-season lambing in Swedish sheep breeds, the aim of this master thesis is to study the variation in frequency of two alleles in the MTNR1A gene in the three breeds; Gotland, Swedish Finewool, and Roslag sheep.
Synchronous Latency Insensitive Design in FPGA
A design methodology to mitigate timing problems due to long wire delays is proposed. The timing problems are taking care of at architecture level instead of layout level in this design method so that no change is needed when the whole design goes to backend design. Hence design iterations are avoided by using this design methodology. The proposed design method is based on STARI architecture, and a novel initialization mechanism is proposed in this paper. Low frequency global clock is used to synchronize the communication and PLLs are used to provide high frequency working clocks.
Volymsrapportering vid drivningsarbete
Reporting harvested and forwarded volumes are important for the forest industry as it provides information of the size of the stock and facilitates logistics. Figures from Holmen Skog show low reporting frequency. The purpose of this study is to investigate the reason and find suggestions for improvement. A total of 17 machine operators were interviewed using a questionnaire combined with open questions. The results show that the majority of the machine operators find it simple to use the reporting system, although, some of them reports that it doesn?t always work as supposed to.
Hur inverkar kontrollbordet på frekvenskurvan vid lyssningsposition i kontrollrummet när placeringar av högtalaren och lyssningsposition placerats efter ITU-R BS.1116-1 rekommendation?
The acoustics in a control room is a complicated phenomenon. Early reflections, reverberation time and area in the room are some of the problems. This report is about the reflection on the mixing console in a control room. The control room being built, these reflections are difficult to take into consideration since the mixing console is one of the very last items you place in the room. This report will explain three main measurements that were done in order to get the answer to the following question: Does the mixing console interfere the frequency curve at listening position? Three measurements were done and the difference between the measurements was that the microphone and the loudspeakers were placed in different places in the control room.
Minkvalpars beteende i större berikade burar vid olika gruppstorlek :
Farmed mink often perform stereotypic behaviours which is considered to be a sign of reduced welfare. Previous studies have shown that enriched cages can reduce the frequency of performed stereotypies. Most studies on mink in Sweden have been done on adults. The aim of this study was to investigate if larger enriched cages with two or four mink kits reduce stereotypies in mink kits during their growth period in comparison to traditional cages.
In the present study the behaviours of mink kits that were kept in four different treatments at a private mink farm were recorded. Traditional cages with two mink kits were used as a reference and the other treatments consisted of larger cages with shelves with two kits, larger cages with shelves and a plastic cylinder with two kits, and larger cages with shelves with four kits.
LJUDETS NATUR, Ämnesövergripande undervisning i musik, NO, teknik, data och svenska på mellanstadiet.
This paper discusses sound education within school subjects such as music, science, engineering, computer science, and Swedish to classes at the intermediate stage..
Subjektiv och objektiv bedömning av underlag på svenska hopptävlingar på elit- och nationell nivå
Bark-stripping by red deer (Cervus elaphus) cause extensive damage to economically valuable spruce trees (Picea abies) in Swedish forests. The underlying causes for bark-stripping are not fully understood, and the frequency and severity of damage unpredictably differ between regions. In this study, I investigated if landscape structure (e.g. agricultural dominated landscape opposed to forest dominated landscape), forage availability, population density and disturbance (e.g. roads and settlements) affect bark-stripping frequency.
Intermediate domain? : En intervjustudie med förskollärare
Den här uppsatsen handlar om hur förskollärare idag upplever samarbetet mellan förskola och hem, deras beskrivning av förutsättningar för ett gott samarbete och vilken betydelse den nya reviderade läroplanen (Lpfö98/10) har för samarbetet.Syftet med uppsatsen är att undersöka hur förskollärare upplever samarbetet hem- förskola. Den empiriska delen grundas på sex intervjuer med förskollärare som har avlagt sin examen under fyra olika decennier. Intervjuerna har genomförts med fokus på att lyfta fram deras syn på de barndomssociologiska begreppen being och becoming (med svensk översättning varandesyn och projektsyn) och frågor kring just samarbetet förskola - hem.De fyra teman som uppstod ur analys av intervjuresultatet var: 1. Växelverkan mellan being och becoming, 2. Samarbete påverkat av den dagliga dialogen och förskollärares uppdrag, 3.
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..
Factors affecting bark-stripping by red deer (Cervus elaphus) : the importance of landscape structure and forage availability
Bark-stripping by red deer (Cervus elaphus) cause extensive damage to economically valuable spruce trees (Picea abies) in Swedish forests. The underlying causes for bark-stripping are not fully understood, and the frequency and severity of damage unpredictably differ between regions. In this study, I investigated if landscape structure (e.g. agricultural dominated landscape opposed to forest dominated landscape), forage availability, population density and disturbance (e.g. roads and settlements) affect bark-stripping frequency.