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Veränderung der Oberflächenbeschaffenheit eines dentalen Implantates nach Sondierung: Eine In-Vitro-Analyse mittels Laserscanning-MikroskopieBetthäuser, Madlena 04 August 2020 (has links)
Material und Methoden:
Insgesamt 40 Proben glatter und rauer Oberflächen von Titanimplantaten wurden mit Parodontalsonden aus Metall oder Kunststoff in einem Winkel von 20° oder 60° bearbeitet. Zur Bestimmung verschiedener standardisierter 2D- und 3D-Rauheitsparameter wurden die Titanoberflächen mit einem konfokalen Laser-Scanning-Mikroskop (CLSM) vor und nach der Durchführung evaluiert.
Ergebnisse:
Die durchschnittliche Profil- und Oberflächenrauheit (Ra und Sa) zeigten unabhängig vom Sondenmaterial keinen signifikanten Unterschied zwischen behandelten und unbehandelten Proben auf glatten und rauen Oberflächen. Auf glatten Oberflächen führten Metallsonden zu erhöhten Amplitudenrauheiten wobei nur für Rp eine Signifikanz (p = 0,007) erreicht wurde. Raue Oberflächenbereiche wurden nach dem Kontakt mit Metallsonden leicht aber nicht signifikant geglättet. Nach Verwendung von Kunststoffsonden blieb die Oberflächenrauhigkeit von glatten und rauen Bereichen nahezu unverändert. Unabhängig des Sondenmaterials zeigte sich kein Zusammenhang zum Applikationswinkel.
Fazit:
Das Sondieren von Titanimplantaten mit Kunststoffsonden aber auch mit Metallsonden verursacht nur geringe Veränderungen der Oberflächenrauhigkeit. Die klinische Bedeutung dieser Veränderung bleibt ungeklärt.
Klinische Relevanz:
Ultrastrukturelle Veränderungen an Titan-Oberflächen durch periimplantäre Untersuchungen könnten durch die Verwendung von Kunststoffsonden vermieden werden.
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Evaluation of On-Machine Gap Measurement Strategies in Jet-Electrochemical MachiningYahyavi Zanjani, Matin, Hackert-Oschätzchen, Matthias, Martin, André, Schubert, Andreas 05 February 2018 (has links)
Jet Electrochemical Machining (Jet-ECM) is a manufacturing technique that applies a free electrolyte jet to generate the desired shapes [1]. Since the principle of the technique is the same as other techniques of Electrochemical Machining where the material removal takes place based on the anodic dissolution of workpiece, the working distance, which is the distance between nozzle’s front surface and the workpiece surface, is one important parameter of the process. The working distance affects the current density and consequently the geometry removal.
The control of the working distance can be done based on the data gathered before and during machining by surface measurement [2]. This measurement usually is done by using electrostatic probing to detect a limited amount of points of the initial workpiece surface. Since electrostatic probing is comparatively slow, laser triangulation represents an alternative technique to detect a larger amount of points before machining within significantly shorter time [3]. In addition to electrostatic probing and laser triangulation, the actual working distance can be measured during the machining process to realize constant working distance. This can be done by detecting electrical signals like the actual total current. This method can be combined with pre-machining measurement by laser triangulation in order to ensure the prevention of any collision between the nozzle and the workpiece.
In this study, on-machine metrology techniques for measuring the working gap as well as current measurements will be compared. Besides, the advantages and disadvantages of these techniques will be systematized. In further studies, the possibility of combining the techniques will be investigated to enhance Jet-ECM with more accurate measurement techniques.
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Analysis of Internal RF Interferences in MobileBalkorkian, Sevag, Hao, Zhang January 2005 (has links)
Nowadays, mobile phones have greater functionality; a camera, color LCD screen, wireless LAN, Bluetooth, IrDA and others. In the near future wider variety of new functionalities will be added, from high quality voice, high definition video to high data rate wireless channels. As consumer electronics integrate greater functionality and high operating frequencies, their emissions will exceed the specified limits, most of these emissions will be a result of the internal interferences in the mobile phone. Moreover higher operating frequencies will be required to improve the quality of these functionalities, something that will make it more difficult to control these interferences. Internal or external sources of electromagnetic interference can degrade the performance of sensitive analog/digital circuits inside the mobile phone. Moreover the electronic device must satisfy a host of global regulations that limit it’s susceptibility to these interferences, as well as the interference emitted by the device itself. Therefore designing a new electronic device to perform new and exciting functions will not be a pleasant task if it can not meet certain specifications and function as required to adhere to certain global regulations. This thesis project investigates the sources of interference inside a mobile phone; mainly the electromagnetic interferences and its effect on the radio transceiver focusing on the GSM receiver sensitivity. This report is a result of intensive research, an investigation of possible sources of interference, also actual measurements were performed; RSSI, OTA and sniffing measurements; to identify the physical sources of interferences, and their effect on the receiver sensitivity. Finally solutions were recommended and implemented to suppress the interferences due to different sources, mainly through filtering, shielding or proper grounding of signals and components/subsystems in the mobile phone.
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Euplectella Aspergillum’s Natural Lattice Structure for Structural Design & Stability Landscape of Thin Cylindrical Shells with Dimple ImperfectionsSloane, Zoe Y. 21 March 2022 (has links)
The first portion of this thesis assesses the structural application of a bracing design inspired by the deep-sea sponge, Euplectella Aspergillum. Many studies have investigated the natural strength found in the unique skeletal structure of this species. The braced design inspired by the sponge features square frames with two sets of cross-braces that are offset from the corners of each frame, creating a pattern of open and closed cells. This study reports the results of multiple Finite Element Analysis (FEA) computations that compare the described bracing pattern to a more common bracing design used in structural design. The designs are compared in two configurations; the first is a simplified tall building design, and the second is a slender plate design. Results indicate that the sponge’s natural pattern produces considerable mechanical benefit when only considering elastic behavior. However, the same was not true when considering plastic material properties. In conclusion to these observations, the sponge-inspired lattice design is determined to be an efficient alternative to slender-solid plates but not for lateral-resisting systems intended for tall building design.
The second topic of discussion in this thesis concerns the stability of thin cylindrical shells with imperfections. The structural stability of these members is highly sensitive to the size and shape of an imperfection. An accurate prediction of the capacity of an imperfect cylindrical shell can be determined using non-destructive testing techniques. This method does require previous knowledge of the characteristics of the imperfection, which realistically is unknown. In the hope of creating a technique to find the location of an imperfection, this study analyzes the trends in the stability landscapes of the surrounding area of an imperfection. The imperfection of interest in this study has an amplitude equivalent to the thickness of the shell. Using FEA to simulate non-destructive probing tests, it is established that there is a distinct area surrounding the imperfection where the axial load and peak probe force curves show the influence of the imperfection. This area is referred to as the zone of influence and can be used to create an efficient process to locate an imperfection on a thin cylindrical shell.
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Exploring GPT models as biomedical knowledge bases : By evaluating prompt methods for extracting information from language models pre-trained on scientific articlesHellberg, Ebba January 2023 (has links)
Scientific findings recorded in literature help continuously guide scientific advancements, but manual approaches to accessing that knowledge are insufficient due to the sheer quantity of information and data available. Although pre-trained language models are being explored for their utility as knowledge bases and structured data repositories, there is a lack of research for this application in the biomedical domain. Therefore, the aim in this project was to determine how Generative Pre-trained Transformer models pre-trained on articles in the biomedical domain can be used to make relevant information more accessible. Several models (BioGPT, BioGPT-Large, and BioMedLM) were evaluated on the task of extracting chemical-protein relations between entities directly from the models through prompting. Prompts were formulated as a natural language text or an ordered triple, and provided in different settings (few-shot, one-shot, or zero-shot). Model-predictions were evaluated quantitatively as a multiclass classification task using a macro-averaged F1-score. The result showed that out of the explored methods, the best performance for extracting chemical-protein relations from article-abstracts was obtained using a triple-based text prompt on the largest model, BioMedLM, in the few-shot setting, albeit with low improvements from the baseline (+0.019 F1). There was no clear pattern for which prompt setting was favourable in terms of task performance, however, the triple based prompt was generally more robust than the natural language formulation. The task performance of the two smaller models underperformed the random baseline (by at best -0.026 and -0.001 F1). The impact of the prompt method was minimal in the smallest model, and the one-shot setting was the least sensitive to the prompt formulation in all models. However, there were more pronounced differences between the prompt methods in the few-shot setting of the larger models (+0.021-0.038 F1). The results suggested that the method of prompting and the size of the model impact the knowledge eliciting performance of a language model. Admittedly, the models mostly underperformed the baseline and future work needs to look into how to adapt generative language models to solve this task. Future research could investigate what impact automatic prompt-design methods and larger in-domain models have on the model performance. / De vetenskapliga upptäckter som presenteras inom litteraturen vägleder kontinuerligt vetenskapliga framsteg. Manuella tillvägagångssätt för att ta del av den kunskapen är otillräckliga på grund av den enorma mängd information och data som finns tillgänglig. Även om för-tränade språkmodeller utforskas för sin brukbarhet som kunskapsbaser och strukturerade dataförråd så finns det en brist på forskning inom den biomedicinska domänen. Målet med detta projekt var att utreda hur Generative Pre-trained Transformer (GPT) modeller för-tränade på biomedicinska artiklar kan användas för att öka tillgängligheten av relevant information inom denna domän. Olika modeller (BioGPT, BioGPT-Large, och BioMedLM) utvärderas på uppgiften att extrahera relationsinformation mellan entiteter direkt ur modellen genom en textprompt. En prompt formuleras genom naturlig text och som en ordnad trippel, och används i olika demonstrationsmiljöer (few-shot, one-shot, zero-shot). Modellförutsägelser utvärderas kvantitativt som ett multi-klass klassifikationsproblem genom ett genomsnittligt F1 värde. Resultatet indikerade att kemikalie-protein relationer från vetenskapliga artikelsammanfattningar kan extraheras med en högre sannolikhet än slumpen med en trippelbaserad prompt genom den största modellen, BioMedLM, i few-shot-miljön, dock med små förbättringar från baslinjen (+0.019 F1). Resultatet visade inga tydliga mönster gällande vilken demonstrationsmiljö som var mest gynnsam, men den trippelbaserade formuleringen var generellt mer robust än formuleringen som följde naturligt språk. Uppgiftsprestandan på de två mindre modellerna underpresterade den slumpmässiga baslinjen (med som bäst -0.026 och -0.001 F1). Effekten av valet av promptmetod var minimal med den minsta modellen, och one-shot-miljön var minst känslig för olika formuleringar hos alla modeller. Dock fanns det mer markanta skillnader mellan promptmetoder i few-shot-miljön hos de större modellerna (+0.021-0.038 F1). Resultatet antydde att valet av promptmetod och storleken på modell påverkar modellens förmåga att extrahera information. De utvärderade modellerna underpresterade dock baslinjen och fortsatt efterforskning behöver se över hur generativa språkmodeller kan anpassas för att lösa denna uppgift. Framtida forskning kan även undersöka vilken effekt automatiska promptdesignmetoder och större domänmodeller har på modellprestanda.
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Extending the Johnson-Neyman Procedure to Categorical Independent Variables: Mathematical Derivations and Computational ToolsMontoya, Amanda Kay 29 December 2016 (has links)
No description available.
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Functionalization and Evaluation of Nanoparticle Probes for the Development of a 14-Plex Diagnostic assay / Funktionalisering och Utvärdering av Nanopartikel Sonder för Utveckling av 14-Multiplexerad Diagnostisk panelNarmack, Samuel January 2021 (has links)
Detta projekt var ett samarbete mellan Aplex Bio AB och Scilifelab. Projektets mål var att utveckla en molekylär diagnostisk panel med förmågan att detektera och diskriminera mellan 14 olika typer av patogener. Projektet innehåller 4 kapitel med fokus på olika mål. I första kapitlet utvecklades en metod för att karakterisera emissioner av fluorescerande nanopartikel kluster. Den första utvärderade metoden utnyttjade klick-kemi för att binda nanopartiklarna till makrostrukturer uppbyggda av amplifierat DNA. Den andra utvärderade metoden skapade aggregerade komplex av nanopartiklar med amplifierat DNA för att utvärdera partiklarnas emissioner. I kapitel 2 av projektet användes azid-funktionaliserade nanopartiklar levererade av Aplex Bio AB för att tvärbinda DBCO modifierade oligonukleotider. Sedan utvecklades en hybridiserings baserad metod för att kvantifiera relativa mängden oligonukleotider på partiklarna. Denna metod användes för att reproducerbart funktionalisera partiklar och utveckla nanopartikel-sonder som kan binda till DNA genom hybridisering. I kapitel 2 utvärderades även hur effektivt och specifikt de utvecklade nanopartikel-sonderna hybridiserar till DNA. I kapitel 3 utvärderades amplifiering av syntetiska ssDNA sekvenser valda från genetiska markörer av 14 patogener, DNA amplifierades med metoden RCA. Målet var att utvärdera specificiteten av amplifieringen. Specifik amplifiering av varje DNA sekvens i panelen var en förutsättning för att möjliggöra detektion och diskriminering av alla patogener i panelen. I kapitel 4 var målet att utveckla en kostnadseffektiv metod för att funktionalisera nanopartiklar med oligonukleotid sekvenser. För att göra detta användes DBCO-NHS-ester reagens och amin-modifierade oligonukleotider. Förverkligande av detta projekt skulle skapa en diagnostisk panel med potentialen att påverka det diagnostiska fältet på en global skala. När detta projekt är fullt utvecklat kan panelen modifieras för detektion av önskade DNA/RNA sekvenser vilket möjliggör ett mångfalt av applikationer, detta skulle göra panelen konkurrerande med dagens diagnostiska metoder då den kan användas i existerande mikroskopiuppsättningar. / This work was a collaboration between Aplex Bio AB and Scilifelab with the aim of developing a molecular assay capable of detecting and discriminating between 14 different pathogenic targets. There are 4 chapters with focus on different goals. In chapter one a method of evaluating emissions of fluorescent nanoparticle clusters was developed. The first approach of evaluating nanoparticle emissions was to utilize click chemistry to bind nanoparticles to macroscale structures of amplified DNA targets. The second evaluated approach was the formation of aggregated complexes of nanoparticles and amplified DNA targets. The second chapter of the thesis used azide functionalized nanoparticles supplied by Aplex Bio AB to utilize azide groups as crosslinkers and use them to functionalize the nanoparticles with DBCO oligos. A hybridization-based method was then developed to quantify relative oligo densities on the nanoparticles, enabling reproducible oligo functionalization of nanoparticles, producing nanoparticle probes that can bind to DNA. The final task of chapter 2 was evaluating the binding efficiency and specificity of the developed nanoparticle probes. The third chapter of the thesis evaluated amplification of synthetic ssDNA sequences corresponding to genetic markers of 14 pathogenic targets using RCA. The goal was to confirm specificity of chosen padlock probes and corresponding synthetic targets for each pathogen. Specific amplification of each target was a prerequisite to enable detecting and discriminating between the 14 pathogenic targets. In chapter 4 the goal was to develop a cost-effective method of oligo functionalization for nanoparticles. This chapter evaluated two main approaches of using DBCO-NHS-ester reagents to perform DBCO modification of amine-oligos. The realization of this work would develop an assay that has the potential to impact the field of diagnostics on a global scale. When fully developed, the molecular assay can be modified to detect any RNA/DNA targets which enables numerous applications, making the assay a competitive diagnostic tool which can be implemented in existing microscopy systems.
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Load Learning and Topology Optimization for Power NetworksBhela, Siddharth 21 June 2019 (has links)
With the advent of distributed energy resources (DERs), electric vehicles, and demand-response programs, grid operators are in dire need of new monitoring and design tools that help improve efficiency, reliability, and stability of modern power networks. To this end, the work in this thesis explores a generalized modeling and analysis framework for two pertinent tasks: i) learning loads via grid probing, and; ii) optimizing power grid topologies for stability. Distribution grids currently lack comprehensive real-time metering. Nevertheless, grid operators require precise knowledge of loads and renewable generation to accomplish any feeder optimization task. At the same time, new grid technologies, such as solar panels and energy storage units are interfaced via inverters with advanced sensing and actuation capabilities. In this context, we first put forth the idea of engaging power electronics to probe an electric grid and record its voltage response at actuated and metered buses to infer non-metered loads. Probing can be accomplished by commanding inverters to momentarily perturb their power injections. Multiple probing actions can be induced within a few tens of seconds. Load inference via grid probing is formulated as an implicit nonlinear system identification task, which is shown to be topologically observable under certain conditions. The analysis holds for single- and multi-phase grids, radial or meshed, and applies to phasor or magnitude-only voltage data. Using probing to learn non-constant-power loads is also analyzed as a special case. Once a probing setup is deemed topologically observable, a methodology for designing probing injections abiding by inverter and network constraints to improve load estimates is provided. The probing task under noisy phasor and non-phasor data is tackled using a semidefinite-program relaxation. As a second contribution, we also study the effect of topology on the linear time-invariant dynamics of power networks. For a variety of stability metrics, a unified framework based on the H2-norm of the system is presented. The proposed framework assesses the robustness of power grids to small disturbances and is used to study the optimal placement of new lines on existing networks as well as the design of radial topologies for new networks. / Doctor of Philosophy / Increased penetration of distributed energy resources such as solar panels, wind farms, and energy storage systems is forcing utilities to rethink how they design and operate their power networks. To ensure efficient and reliable operation of distribution networks and to perform any grid-wide optimization or dispatch tasks, the system operator needs to precisely know the net load (energy output) of every customer. However, due to the sheer extent of distribution networks (millions of customers) and low investment interest in the past, distribution grids have limited metering infrastructure. Nevertheless, data from grid sensors comprised of voltage and load measurements are readily available from a subset of customers at high temporal resolution. In addition, the smart inverters found in solar panels, energy storage units, and electric vehicles can be controlled within microseconds. The work in this thesis explores how the proliferation of grid sensors together with the controllability of smart inverters can be leveraged for inferring the non-metered loads i.e., energy output of customers that are not equipped with smart inverters/sensors. In addition to the load learning task, this thesis also presents a modeling and analysis framework to study the optimal design of topologies (how customers are electrically inter-connected) for improving stability of our power networks.
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Analysis of the results and it influence factors of dynamic probing test and interrelation with cone penetration test data in Lithuanian soils / Dinaminio zondavimo rezultatų ir juos įtakojančių veiksnių analizė bei sąsajos su statinio zondavimo duomenimis Lietuvos gruntuoseŽaržojus, Gintaras 30 December 2010 (has links)
The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence. / Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio.
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Dinaminio zondavimo rezultatų ir juos įtakojančių veiksnių analizė bei sąsajos su statinio zondavimo duomenimis Lietuvos gruntuose / Analysis of the results and it influence factors of dynamic probing test and interrelation with cone penetration test data in Lithuanian soilsŽaržojus, Gintaras 30 December 2010 (has links)
Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio. / The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence.
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