Page 139 not included in the thesis. / <p> The problem of coherent carrier recovery and the effects of phase error on the performance of an offset quadrature-phase-shift-keying (QPSK) duobinary system have been investigated in the thesis. The system of interest is similar to RD -3 digital system that is being developed and installed as an efficient high data-rate digital radio communication system by Bell Northern Research Laboratory (BNR). </p> <p> Four carrier regeneration loop structures are investigated and analysed in the thesis. These are: (i) estimate-aided suppressed carrier loop (ii) decision-directed feedback loop (iii) shifted decision-directed feedback loop (iv) half-shifted decision-directed feedback loop All of these loop structures employ the technique of data-aided carrier synchronization. The estimate-aided loop structure exhibits steadystate behavior similar to that of a conventional Costas loop. The remaining three loop structures differ from the estimate-aided loop in the sense that they require decisions to make on the noisy received signal. These are then fedback to the carrier recovery circuit in such a way as to create a spectral line at carrier frequency. The loop behavior in the presence of additive noise has been investigated in some detail. For each loop, analytical expressions for the phase detector characteristic (S-curve) and the steady-state phase error probability density function (pdf) are derived, and provide a means of comparing the performance of the different recovery schemes.</p> / Thesis / Master of Engineering (MEngr)

Position and navigation of vehicle in two and three dimensions have been important as being advanced technology. Therefore, some system has been evaluated to get information of vehicle&rsquo / s position. Main problem in navigation is how to determine position and rotation in three dimensions. If position and rotation is determined, navigation will also be determined with respect to their initial point. There is a technology that vehicle velocity can be discovered, but a technology that rotation can be discovered is needed. Sensor which sense rotation is called gyroscope. If this instrument consists of optical and solid state material, it&rsquo / s defined by Fiber Optic Gyroscope (FOG). There are various studies in order to increase the sensitivity of fiber optic gyroscopes, which is an excellent vehicle for sensing rotation. One of them is interferometric fiber optic gyroscope with amplified optical feedback (FE_FOG). In this system, a feedback loop, which sent the output pulse through the input again, is used. The total output is the summation of each interference and it is in pulse state. The peak position of the output pulse is shifted when rotation occurs. Analyzing this shift, the rotation angle can be determined. In this study, fiber optic gyroscopes, their components and performance characteristics were reviewed. The simulation code was developed by VPIsystems and I used VPItransmissionMakerTM software in this work. The results getting from both rotation and nonrotation cases were analyzed to determine the rotation angle and sensitivity of the gyroscope.

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Bakgrund: Under senare år har allt fler kliniska träningscentra för färdighetsträning etablerats för att möjliggöra en trygg och säker lärandemiljö med simuleringsmöjligheter för studerande och personal. Klinisk färdighetsträning är en viktig del i sjuksköterskeutbildningen vid Högskolan Dalarna (HDa) där lärandemiljön på Kompetenscentrum (KC) kan bidra till en förbättring av lärandemiljön i den kliniska färdighetsutbildningen. Syfte: Syftet med denna studie var att undersöka sjuksköterskestudenters upplevelser via skattning av lärandemiljön för klinisk färdighetsutbildning före och efter inrättandet av Kompetenscentrum. Metod: Studien genomfördes som en enkätundersökning med kvasiexperimentell design. Enkätens baserades på Saarikoski och Leino-Kilpis mätinstrument CLES där frågeställningar om lärandemiljön modifierades med hjälp av Delphimetoden utifrån de tre olika dimensionerna: utbildningsmiljö, relation och lärarens roll. Mätningen före inrättandet genomfördes under hösten 2010 och mätningen efter inrättandet genomfördes hösten 2011. Totalt ingick 266 sjuksköterskestudenter i studien varav 198 (74 %) besvarade enkäten. Resultat: Sjuksköterskestudenter skattade upplevelsen av lärandemiljön mer positiv efter inrättandet av Kompetenscentrum där resultatet visar en signifikant högre skattning i 8 de av de 16 frågorna. Sjuksköterskestudenterna skattade att de upplever att utbildningsmiljön är mer verklighetstrogen, de är mer nöjda med färdighetsträningen samt att den inspirerar dem till att arbeta som sjuksköterska. Att relationen mellan dem och läraren bygger på respekt och att det är en mer positiv atmosfären under färdighetsträningen. Däremot påvisades ingen signifikant skillnad i studenternas upplevelse av den kliniska lärarens roll. Slutsats: Det är uppenbart att lärandemiljö har betydelse för sjuksköterskestudentens integration av såväl teoretiska som praktiska kunskaper vilket medför att färdigheterna förbättras och ger en bra grund för arbetet som sjuksköterska. Strategier bör vidtas för att vidmakthålla och utveckla lärandemiljön på KC samt fokusera ytterligare på integrering av teori och praktik. / Background: In recent years, an increasing number of clinical training centers for skill training is available to allow for a safe and secure learning environment with simulation opportunities for students and staff. Clinical skill training is an important part of nursing at University College of Dalarna (HDa) where learning environment at the center of excellence (KC) can contribute to an improvement in this part of the training. Aim: The aim of this study was to investigate the nursing students ' experiences through the estimation of learning environment of clinical skill training before and after the establishment of center of excellence. Method: The study was conducted as a survey with quasiexperimental design. The questionnaire was based on Saarikoski and Leino-Kilpis gauges CLES where questions were modified with the help of Delphi method based on the three different dimensions: educational environment, relationship and the teacher's role. The measurement before the establishment was carried out during autumn 2010 and the measurement after establishment occurred in autumn of 2011. A total of 266 students were included in the study, of which 198 (74%) responded to the questionnaire. Result: Nursing students estimated the experience of learning environment more favorable after the establishment of center of excellence where the results show a significantly higher estimate in 8 of the 16 questions. Nursing students´ believe that the training environment is more realistic, they are more satisfied with skill training and that inspires them to work as a nurse. The relationship between them and the teacher is based on respect and that opens up to a more positive atmosphere during skill training. On the other hand, no significant difference in the student’s experience of the clinical teacher's role was noticed. Conclusion: It is clear that the learning environment is important for nurse student's integration of theoretical as well as practical knowledge and skills improvement and provides a good basis for work as a nurse. Strategies should be taken to maintain and develop the learning environment at KC and focus more on the integration of theory and practice.

<p>One of the key mechanisms that mediate renal autoregulation is the tubuloglomerular feedback (TGF) system, which is a negative feedback loop in the kidney that balances glomerular filtration with tubular reabsorptive capacity. In this dissertation, we develop several mathematical models of the TGF system to study TGF-mediated model dynamics. </p><p>First, we develop a mathematical model of compliant thick ascending limb (TAL) of a short loop of Henle in the rat kidney, called TAL model, to investigate the effects of spatial inhomogeneous properties in TAL on TGF-mediated dynamics. We derive a characteristic equation that corresponds to a linearized TAL model, and conduct a bifurcation analysis by finding roots of that equation. Results of the bifurcation analysis are also validated via numerical simulations of the full model equations. </p><p>We then extend the TAL model to explicitly represent an entire short-looped nephron including the descending segments and having compliant tubular walls, developing a short-looped nephron model. A bifurcation analysis for the TGF loop-model equations is similarly performed by computing parameter boundaries, as functions of TGF gain and delay, that separate differing model behaviors. We also use the loop model to better understand the effects of transient as well as sustained flow perturbations on the TGF system and on distal NaCl delivery.</p><p>To understand the impacts of internephron coupling on TGF dynamics, we further develop a mathematical model of a coupled-TGF system that includes any finite number of nephrons coupled through their TGF systems, coupled-nephron model. Each model nephron represents a short loop of Henle having compliant tubular walls, based on the short-looped nephron model, and is assumed to interact with nearby nephrons through electrotonic signaling along the pre-glomerular vasculature. The characteristic equation is obtained via linearization of the loop-model equations as in TAL model. To better understand the impacts of parameter variability on TGF-mediated dynamics, we consider special cases where the relation between TGF delays and gains among two coupled nephrons is specifically chosen. By solving the characteristic equation, we determine parameter regions that correspond to qualitatively differing model behaviors. </p><p>TGF delays play an essential role in determining qualitatively and quantitatively different TGF-mediated dynamic behaviors. In particular, when noise arising from external sources of system is introduced, the dynamics may become significantly rich and complex, revealing a variety of model behaviors owing to the interaction with delays. In our next study, we consider the effect of the interactions between time delays and noise, by developing a stochastic model. We begin with a simple time-delayed transport equation to represent the dynamics of chloride concentration in the rigid-TAL fluid. Guided by a proof for the existence and uniqueness of the steady-state solution to the deterministic Dirichlet problem, obtained via bifurcation analysis and the contraction mapping theorem, an analogous proof for stochastic system with random boundary conditions is presented. Finally we conduct multiscale analysis to study the effect of the noise, specifically when the system is in subcritical region, but close enough to the critical delay. To analyze the solution behaviors in long time scales, reduced equations for the amplitude of solutions are derived using multiscale method.</p> / Dissertation

A feedback loop is a method used to collect, store and handle provided feedback. It also includes methods for working with lessons learned since learnings are seen as the backbone of feedback loops, since they cannot be successful without learnings. Research regarding knowledge development, particularly feedback loops and lessons learned, is in need for further research to understand how industrial organisations working with digital automation and processes can work with and manage feedback and lessons learned in a cross-functional and co-productive setting. To study this, the research was conducted through a co-production between the researcher and ABB AB as a case company. The collaboration allowed for deep insights in work methods, as well as how feedback loops are worked with and used today along with desired methods for feedback loops and sharing of lessons learned. To achieve this, multiple user interviews were conducted as well as an observation and meetings with other stakeholders and follow-up sessions with the case company. This study also compares perspectives of existing feedback loops with each other as well as a new developed feedback loop designed for industrial organisations working with digital automation and digital processes.

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Abstract  Master thesis in Business Administration, School of Business and Economics Linnaeus University 4FE17E VT2022  Authors: Eric Månsson &amp; Marcus Nykvist  Supervisor: Magnus Willesson  Examiner: Christopher von Koch  Title: Identifying Reflexivity  Keywords: Reflexivity, EMH, AMH, fundamental value, market value, feedback loop, cognitive function, manipulative function.  Background: Current economic theory describes the risks the financial markets face as exogenous in nature. Several studies suggest the presence of an unaccounted-for risk which is not exogenous in nature but endogenous. Seemingly, the initial risk is exogenous but through the interaction between the market and its participants this risk can be either amplified or dulled. As such, current economic theory illustrates only partially the risks of financial markets as they do not account for endogenous risk. A theory is necessary which not only acknowledges the influence of exogenous risk but also considers the impact of endogenous risk after the fact. The theory of reflexivity offers a solution to this problem as it considers the interactions between the market and its participants and how these two affect each other, through the so-called cognitive- and manipulative function.  Purpose: As reflexivity entails a more complete description of the behavior of financial markets than current economic theory, the purpose of this study is to identify its occurrence.  Method: This study uses a deductive research approach along with a quantitative strategy to test its purpose. The utilized model is constructed through the theory of reflexivity and the implications this theory poses toward statistical testing. The study conducts its testing on a random sample of firms from the S&amp;P 500 between 1992-2021 using annual data.  Results: The results of the study are invalidated due to the use of weak instruments in the market model, and due to a lack of endogeneity in the fundamental model. As such, the occurrence of reflexivity cannot be confirmed through this study. An interesting ancillary finding however is a methodological implication which suggests that different proxies for fundamental value as well as different instrumental variables may be necessary given a certain context to identify endogeneity and instrumental relevance respectively. / Sammanfattning  Examensarbete, Ekonomihögskolan vid Linnéuniversitetet, Företagsekonomi 4FE17E VT2022  Författare: Eric Månsson &amp; Marcus Nykvist  Handledare: Magnus Willesson  Examinator: Christopher von Koch  Titel: Identifying Reflexivity  Sökord: Reflexivity, EMH, AMH, fundamental value, market value, feedback loop, cognitive function, manipulative function.  Bakgrund: Nuvarande ekonomiska teorier behandlar de risker som finns på de finansiella marknader som exogena. Hursomhelst, flertalet studier indikerar att det även finns risker som inte har tagits i beaktning och som eventuellt kan anses vara endogena. Det verkar därmed som att den ursprungliga risken är endogen, men genom samspelet mellan marknad och dess deltagare kan denna stärkas eller dämpas. Till följd av detta verkar det som att de nuvarande ekonomiska teorierna bara tar hänsyn till en del av alla de risker som existerar på de finansiella marknaderna. Med andra ord, det behövs en teori som inte bara tar hänsyn till de exogena riskerna, men som också uppmärksammar de endogena riskerna. Reflexivity erbjuder en sådan lösning i och med dess hänseende till interaktionen mellan marknad och marknadsdeltagare och dessas påverkan på varandra genom de så kallade kognitiva och manipulativa funktioner.  Syfte: Syftet med detta arbete är att identifiera reflexivity på marknaderna, eftersom att denna teori erbjuder en mer heltäckande beskrivning av marknadsbeteendet.  Metod: Tillvägagångssättet i denna studie är i form av en deduktiv forskning med en kvantitativ strategi för att testa syftet. Modellen som används är uppbyggd genom reflexivity-teorin och dess innebörd som denna teori har för statistisk testning. Testningen utgår från ett slumpmässigt urval av företag från S&amp;P 500 mellan 1992 och 2021 på en årlig basis.  Resultat: Resultaten från denna studie ogiltigförklarades på grund av svaga instrumentala variabler i testningen och till följd av bristande endogenitet i den fundamentala modellen. Det gick därmed inte att bekräfta förekomsten av reflexivity genom denna studie.

This study investigates feedback loop thinking and novices' skills in identifying feedback loops, aiming to create a valid assessment tool that distinguishes real understanding from mere awareness. The validity of the tool is assessed in two ways, 1) using it to test hypotheses about feedback learning by deploying the tool to test the effects of the terms used to name a feedback loop, and outcome desirability on loop identification accuracy determined by a signal detection analysis, and 2) using an item response analysis to determine the value of each item in distinguishing among students with a range of understanding of feedback loops. Results show little effect of terminology on sensitivity or bias, suggesting educators can use their field’s preferred terms without compromising outcomes, but a clear effect of the desirability of outcome on both sensitivity and bias, with a small increase in sensitivity and a clear bias to classify items as loops if they have a good outcome. The analysis of item sets for both positive and negative feedback loop using Item Response Theory (IRT) identified 16 items for each type of loop that provided a range of difficulties and discrimination over a moderately broad range of skill. Model fit favored a 2PL model, but global fit statistics were precluded by missing data. Still, this project delivers a reliable task for understanding feedback loop thinking, a crucial step for enabling future research on complex causal relationships. Subsequent studies should focus on assessing the unidimensionality of the item sets and elucidating the differences in how novices perceive positive versus negative feedback loops. Such efforts will further advance our understanding of feedback loop cognition. / Psychology