A safe electrical connection between the human body and the recording circuit is required for the acquisition of physiological signals such as the electrocardiogram (ECG), electroneurogram (ENG), or electromyogram (EMG). The recording chip is conventionally connected to the human body through a blocking capacitor. The capacitor avoids any DC current flowing from the recording system into the patient¡¦s body in the case of chip failure. However, the large capacitor area in an integrated chip and its effect on the signal transform function make the use of a coupling capacitor undesirable. In principle, a DC-coupled system can be used to overcome this limitation. The DC-coupled amplifier connects directly to the patient. However, a DC failure current caused, for example, by a gate-oxide short failure could harm the patient. To detect a dangerous condition, a safety monitoring system is proposed in this thesis. The safety monitoring system applies a test signal and physiological signals to the amplifier input. The disappearance of the test signal in the event of circuit failure is detected at the amplifier output. The recording system can then be switched into a safe state. The analysis of the monitoring system, its design procedure and simulation results are presented in this thesis. Moreover, the first measured results are reported for a system realized as an integrated circuit in TSMC 0.35 £gm 2P4M CMOS process technology.

Acoustic signals are widely used by fish such as pomacentrids, to communicate during courtship and agonistic activities. Adult Stegastes lividus holds a permanent territory in a coral reef environment. Previous studies suggested that S. lividus seems to produce clicking sounds when intruders close to its territory. This study aimed to describe (1) the sounds produced by this species; (2) the behavioral pattern associated with these acoustic signals; (3) vocal activity of diurnal variation. The study site was near the water inlet of the Third Nuclear Power Plant in southern Taiwan (120¡C45¡¬E , 21¡C57¡¬N). 24-hour recordings at the habitat of S. lividus at 5-6 m and at 2-3 m were made in February, March and April, 2005. The synchronous video-audio recordings were also made at the colonies of S. lividus at 2-3 m. The observations showed that S. lividus produced clicking sounds for territorial defense (e.g. aggressive behavior). These sounds were composed of a variable number of pulses that had a dominant frequency at 200 to 400 Hz. Stegastes lividus produced different sound types to defend against conspecifics or heterospecifics. Although the acoustic signals were emitted throughout all day, more sounds were recorded during the noon, fewer sounds at night, and a small peak presented at sunset. Therefore, I suggested the acoustic signals of S. lividus may be also serves as species recognition. The fish may be a diurnal fish, and its social interaction peaks at noon.

The METU Gait Analysis System employs a computer program called Kiss-GAIT for the calculation of joint angles, moments and powers using force plate data and marker trajectories as input. Kiss-GAIT was developed using Delphi and is confined to calculations related to the standard gait protocol. Because the code lacks the flexibility required to carry out various test cases, the inverse dynamics formulation being used could not be verified and the extent of the error propagation problem could not be determined so far. The first aim of this study was to develop a code for the inverse dynamics model of the METU Gait Analysis System making use of the flexible programming environment provided by MATLAB. Verified and more reliable analysis results, obtained by reformulating the inverse dynamics algorithm in a new code, are presented. Secondly, data smoothing and differentiation techniques conventionally used in gait analysis were critically reviewed. A common tool used for filtering marker trajectories is the Butterworth digital filter. This thesis presents a modified, adaptive version of this classical tool that can handle non-stationary signals owing to its coefficients which are functions of local signal structure. The results of this thesis indicate the dominancy of ground reactions as compared to inertial effects in normal human gait. This implies that the accuracy needed in body segment inertial parameter estimation is not a critical factor. On the other hand, marker trajectories must be as accurate as possible for meaningful kinetic patterns. While any smoothing and differentiation routine that produces reasonable estimates is sufficient for joint moment calculation purposes, the estimation performance becomes a key requirement for the calculation of joint powers.

GPS is a widely accepted means of navigation, whether it is for civilian or military means. With the implementation of GPS on smart projectiles, these weapons have been able to achieve remarkable accuracy. Even though the improvements in accuracy are impressive, GPS signals are susceptible to jamming and spoofing by a sufficiently motivated enemy. The work reported here examines the viability of constructing a navigation solution using ground based signals of opportunity that provide range and range rate information. Using a generalized sensor model encompassing the key error terms, a variety of physical devices are included in the analysis. For a typical indirect fire trajectory, navigation solutions are computed as a function of the number and density of signal sources, terrain type, and sensor errors. Systematic studies were performed using these parameters in order to better understand the merits and demerits of this type of system to create a useful navigation solution. Based on these studies, results indicate that navigation solutions can be computed with the same accuracy as current GPS systems with a moderate number of signal sources. Generally, more accurate solutions are obtained when the projectile is directly over the signal sources and there is variation of signal source location in all three axes.

No description available.

Navigation is an invisible utility that is often taken for granted with considerable societal and economic impacts. Not only is navigation essential to our modern life, but the more it advances, the more possibilities are created. Navigation is at the heart of three emerging fields: autonomous vehicles, location-based services, and intelligent transportation systems. Global navigation satellite systems (GNSS) are insufficient for reliable anytime, anywhere navigation, particularly indoors, in deep urban canyons, and in environments under malicious attacks (e.g., jamming and spoofing). The conventional approach to overcome the limitations of GNSS-based navigation is to couple GNSS receivers with dead reckoning sensors. A new paradigm, termed opportunistic navigation (OpNav), is emerging. OpNav is analogous to how living creatures naturally navigate: by learning their environment. OpNav aims to exploit the plenitude of ambient radio frequency signals of opportunity (SOPs) in the environment. OpNav radio receivers, which may be handheld or vehicle-mounted, continuously search for opportune signals from which to draw position and timing information, employing on-the-fly signal characterization as necessary. In collaborative opportunistic navigation (COpNav), multiple receivers share information to construct and continuously refine a global signal landscape. For the sake of motivation, consider the following problem. A number of receivers with no a priori knowledge about their own states are dropped in an environment comprising multiple unknown terrestrial SOPs. The receivers draw pseudorange observations from the SOPs. The receivers' objective is to build a high-fidelity signal landscape map of the environment within which they localize themselves in space and time. We then ask: (i) Under what conditions is the environment fully observable? (ii) In cases where the environment is not fully observable, what are the observable states? (iii) How would receiver-controlled maneuvers affect observability? (iv) What is the degree of observability of the various states in the environment? (v) What motion planning strategy should the receivers employ for optimal information gathering? (vi) How effective are receding horizon strategies over greedy for receiver trajectory optimization, and what are their limitations? (vii) What level of collaboration between the receivers achieves a minimal price of anarchy? This dissertation addresses these fundamental questions and validates the theoretical conclusions numerically and experimentally. / text

Acoustic emission is a widely used nondestructive technique for identification of structural damage. The AE technique relies on transient energy waves generated by the materials during their failure. As for soils, the basic causes of acoustic emission are the mechanisms which are responsible for shearing of soils. Mobilization of shear strength within a soil itself and the interaction of the soil with the adjacent natural or construction materials are directly related to the level of acoustic emission in soils. It is envisioned that acoustic emission signals in deforming soils can be used as an early warning sign in real time landslide-monitoring systems.This thesis study uses a laboratory experimental setup to record the acoustic emission signals emitted during the shearing of cohesionless soils. Several tests were performed with different rates of shearing with parallel (horizontal) and perpendicular (vertical) placement of the AE mote- sensor with respect to the shear plane. Since the original raw signals recorded contain large amounts of noise, it is necessary to de-noise them. The current study uses wavelet and FFT to de-noise the original signals. The filtered signals obtained using wavelet analysis and FFT are compared to determine the suitability of the two techniques. The peak AE values and the time taken to observe an initial visible peak under different conditions are reported in this study. It is observed that relatively faster rates of shearing generate more AE signals compared to slower rates of shearing. In addition, the rapid shearing produces initial visible peak AE activities within a short period of time than in slow rate of shearing.

Bakgrund: Sedan 2010 är revisionsplikten för de små företagen i Sverige avskaffad vilket innebär att småföretagare idag har valmöjlighet för frivillig revision. Den främsta anledningen till att slopa revisionsplikten var att revisionen är en onödig, tidskrävande och kostsam aktivitet för småföretag. Många företag som berördes av reformen använde sig av den valmöjligheten vilket medför att 60 procent av småföretag i nuläget har valt bort revision. Dock finns det fortfarande 40 procent som finner att revisionen tillför en nytta och betraktar den som en viktig del av verksamheten. Detta tyder på att företag har delade åsikter om revisionens betydelse och värde och därmed olika benägenhet att välja att genomgå revision. Syfte: Syftet med studien är att få en ökad förståelse för hur revision och småföretagens beslut att behålla revision skapar mening och undersöka bakomliggande meningsskapandefaktorer till valet att fortsätta att ha revision. Metod: Studien har baserats på en kvalitativ forskningsmetod. Undersökningsobjekten utgjordes av sex småföretag inom byggbranschen belägna i Västra Götaland och Jönköpings län. Sex semistrukturerade besöksintervjuer med företagsägare genomfördes för att undersöka fenomenet. Det empiriska materialet har sedan analyserats utifrån analysmodellen för att kunna besvara studiens problemformulering. Slutsats: Respondenterna har en positiv attityd till revision och har olika anledningar till att behålla den. Främsta anledningarna att välja revision är egen trygghet och strävan efter att förvalta verksamheten lagenligt. Vi finner att resultatet visar att revision är en meningsskapande aktivitet som leder till att företaget behåller den och därmed skapar mening med sitt val. Företagen skapar mening med sitt val genom att sända positiva signaler till omgivningen och därmed differentierar sig och skapar en identitet. Tidigare erfarenheter är den främsta meningsskapande faktorn som påverkar beslutsfattande som i sin tur leder till att meningen skapas både retrospektivt och prospektivt. / Background: Since 2010 the provision of statutory audit for small enterprises has been abolished in Sweden. In accordance with this new legislation micro entrepreneur now have the choice for voluntary audit. The main reason behind the abolishment of statutory audit was that auditing as an activity was unnecessary, an administrative burden and a financial cost burden to small enterprises. Many of Swedish enterprises that were affected by the reform of statutory audit exemption used this option of choice, currently it has resulted in that 60 percent of small enterprises have chosen not to have audits. This means that 40 percent of enterprises who still keep their audit find benefits of being audited and view it as an important part of business. This indicates that the enterprises have different opinions about the audit’s importance and value, and thus different tendency to choose to undergo a voluntary audit. Purpose: This study aims to have an increased understanding of how audits and micro entrepreneurs' decision of keeping audits makes sense and to examine the underlying factors of making sense for choosing to continue to have an audit. Methods: This study has a qualitative research method. The respondents of the survey consisted of sex small enterprises in the construction industry, seated in Västra Götaland and Jönköpings County (län). To explore the phenomenon of the study, semi-structured interviews were carried out with owners of six small enterprises. The empirical data was then analysed from our analysis model to answer the study’s research question. Conclusions: The respondents have a positive attitude to audits and have different reasons to keep it. The main reasons behind the choice to continue with audits, are own security and the aim to conduct legal business. We find that the results show that audit is a sense making activity which results in why enterprises keep it, and therefore making sense with their choice of audit. Enterprises make sense of their choice by sending positive signals to environment, and therefore differentiate themselves and make identity. Previous experience is the main factor of sense making which affects the decision-making which in turn leads to that meaning is both retrospective and prospective.

No description available.

The main aims of automatized environment of theoretical researches are to help and accelerate complicated signals' processing, creation of algorithms of neurons' networks, filters and other symbolic and calculation engineering researches which can be understood and promoted by every person. The environment has been implemented using simple as possible interaction of machine and the human communication and the possibility to actuate into research bases of systems of knowledge.