Cross-layer latency-aware and -predictable data communication

Cyber-physical systems are making their way into more aspects of everyday life. These systems are increasingly distributed and hence require networked communication to coordinatively fulfil control tasks. Providing this in a robust and resilient manner demands for latency-awareness and -predictability at all layers of the communication and computation stack. This thesis addresses how these two latency-related properties can be implemented at the transport layer to serve control applications in ways that traditional approaches such as TCP or RTP cannot. Thereto, the Predictably Reliable Real-time Transport (PRRT) protocol is presented, including its unique features (e.g. partially reliable, ordered, in-time delivery, and latency-avoiding congestion control) and unconventional APIs. This protocol has been intensively evaluated using the X-Lap toolkit that has been specifically developed to support protocol designers in improving latency, timing, and energy characteristics of protocols in a cross-layer, intra-host fashion. PRRT effectively circumvents latency-inducing bufferbloat using X-Pace, an implementation of the cross-layer pacing approach presented in this thesis. This is shown using experimental evaluations on real Internet paths. Apart from PRRT, this thesis presents means to make TCP-based transport aware of individual link latencies and increases the predictability of the end-to-end delays using Transparent Transmission Segmentation.Cyber-physikalische Systeme werden immer relevanter für viele Aspekte des Alltages. Sie sind zunehmend verteilt und benötigen daher Netzwerktechnik zur koordinierten Erfüllung von Regelungsaufgaben. Um dies auf eine robuste und zuverlässige Art zu tun, ist Latenz-Bewusstsein und -Prädizierbarkeit auf allen Ebenen der Informations- und Kommunikationstechnik nötig. Diese Dissertation beschäftigt sich mit der Implementierung dieser zwei Latenz-Eigenschaften auf der Transport-Schicht, sodass Regelungsanwendungen deutlich besser unterstützt werden als es traditionelle Ansätze, wie TCP oder RTP, können. Hierzu wird das PRRT-Protokoll vorgestellt, inklusive seiner besonderen Eigenschaften (z.B. partiell zuverlässige, geordnete, rechtzeitige Auslieferung sowie Latenz-vermeidende Staukontrolle) und unkonventioneller API. Das Protokoll wird mit Hilfe von X-Lap evaluiert, welches speziell dafür entwickelt wurde Protokoll-Designer dabei zu unterstützen die Latenz-, Timing- und Energie-Eigenschaften von Protokollen zu verbessern. PRRT vermeidet Latenz-verursachenden Bufferbloat mit Hilfe von X-Pace, einer Cross-Layer Pacing Implementierung, die in dieser Arbeit präsentiert und mit Experimenten auf realen Internet-Pfaden evaluiert wird. Neben PRRT behandelt diese Arbeit transparente Übertragungssegmentierung, welche dazu dient dem TCP-basierten Transport individuelle Link-Latenzen bewusst zu machen und so die Vorhersagbarkeit der Ende-zu-Ende Latenz zu erhöhen

Reducing Internet Latency : A Survey of Techniques and their Merit

Bob Briscoe, Anna Brunstrom, Andreas Petlund, David Hayes, David Ros, Ing-Jyh Tsang, Stein Gjessing, Gorry Fairhurst, Carsten Griwodz, Michael WelzlPeer reviewedPreprin

Injection laryngoplasty with autologous fascia for treatment of unilateral vocal fold paralysis

The purpose of this dissertation was to study the applicability of minced autologous fascia graft for injection laryngoplasty of unilateral vocal fold paralysis (UVFP). Permanence of augmentation and host versus graft tissue reactions were of special interest. The topic deals with phonosurgery, which is a subdivision of the Ear, Nose and Throat-speciality of medicine. UVFP results from an injury to the recurrent or the vagal nerve. The main symptom is a hoarse and weak voice. Surgery is warranted for patients in whom spontaneous reinnervation and a course of voice therapy fails to improve the voice. Injection laryngoplasty is a widespread surgical technique which aims to restore glottic closure by augmenting the atrophied vocal muscle, and also by turning the paralyzed vocal fold towards midline. Currently, there exists a great diversity of synthetic, xenologous, homologous, and autologous substances available for injection. An autologous graft is perfect in terms of biocompatibility. Free fascia grafts have been successfully used in the head and neck surgery for decades, but fascia had not been previously applied into the vocal fold. The fascia is harvested from the lateral thigh under local anesthesia and minced into paste by scissors. Injection of the vocal fold is performed in laryngomicroscopy under general anesthesia. Three series of clinical trials of injection laryngoplasty with autologous fascia (ILAF) for patients with UVFP were conducted at the Department of Otorhinolaryngology of the Helsinki University Central Hospital. The follow-up ranged from a few months to ten years. The aim was to document the vocal results and possible morbidity related to graft harvesting and vocal fold injection. To address the tissue reactions and the degree of reabsoprtion of the graft, an animal study with a follow-up ranging from 3 days to 12 months was performed at the National Laboratory Animal Center, University of Kuopio. Harvesting of the graft and injection was met with minor morbidity. Histological analysis of the vocal fold tissue showed that fascia was well tolerated. Although some resorption or compaction of the graft during the first months is evident, graft volume is maintained well. When injected deep and laterally into the vocalis muscle, the fascia graft allows normal vibration of the vocal fold mucosa to occur during phonation. Improvement of voice quality was seen in all series by multiple objective parameters of voice evaluation. However, the vocal results were poor in cases where the nerve trauma was severe, such as UVFP after chest surgery. ILAF is most suitable for correction of mild to moderate glottic gaps related to less severe nerve damage. Our results indicate that autologous fascia is a feasible and safe new injection material with good and stable vocal results. It offers a practical solution for surgeons who treat this complex issue.HYKS Korvaklinikalla toteutetussa väitöstutkimuksessa selvitettiin autologisen faskian eli omaa kudosta olevan vapaan lihaskalvosiirteen soveltuvuutta äänihuulihalvauksen kirurgisessa hoidossa. Väitösaihe käsittelee äänihuulikirurgiaa, joka kuuluu korva-, nenä- ja kurkkutautien erikoisalaan. Äänihuulihalvaus on yleisimmin seurausta kasvaimen tai leikkauskomplikaation aiheuttamasta hermovammasta. Pääoire on käheä ja heikko ääni, josta aiheutuu potilaille merkittävä kommunikaatiohaitta. Käheyden voimakkuus ja paranemisennuste riippuu vamman vaikeusasteesta. Lievemmät tapaukset kuntoutuvat puheterapeutin toimesta ääniterapialla. Kirurgiaa tarvitaan vaurioissa, joissa hermon toiminta ei spontaanisti palaudu riittävästi. Injektiolaryngoplastiassa halvaantuneeseen äänihuuleen ruiskutetaan ainetta, joka korvaa surkastuneen lihasmassan ja kääntää äänihuulen keskiviivaan. Toimiva äänihuuli saa siihen näin kontaktin ja ääni palautuu. Täyteaineita on tarjolla laaja valikoima. Potilaan omaa kudosta l. autologista siirrettä käyttämällä vältetään monia ongelmia, joita on liittynyt aiemmin paljon käytettyihin synteettisiin materiaaleihin, kuten Tefloniin ja silikoniin. Kun kokeilut 1990-luvun alussa rasvakudoksella eivät antaneet pysyvää tulosta äänihuulessa, päätettiin Korvaklinikalla kokeilla faskiaa l. lihaskalvoa. Faskiasta on pitkä kokemus mm. tärykalvon paikkausleikkauksista, mutta äänihuulessa sitä ei ollut aiemmin käytetty. Faskiasiirre otetaan paikallispuudutuksessa potilaan reisilihaksesta. Se pilkotaan saksilla pastaksi, potilas nukutetaan ja faskia injisoidaan äänihuuleen leikkausmikroskoopin ja erikoisruiskun avulla. Väitöstutkimus aloitettiin Korvaklinikalla v.1998. Se koostuu eläinkokeesta ja kolmesta potilastutkimuksesta. Eläintyön tavoite oli selvittää faskian aiheuttamat kudosreaktiot ja siirteen pysyvyys äänihuulessa. Potilastutkimusten seuranta-aika vaihteli muutamasta kuukaudesta 10 vuoteen. Niissä tavoitteena oli mitata objektiivisin menetelmin leikkaustulos eli äänen laatu sekä arvioida leikkaustekniikan turvallisuutta ja mahdollisia myöhäisongelmia. Tutkimuksessa osoitettiin, että faskia on hyvin siedetty ja stabiili siirre äänihuulessa. Se ei aiheuta vierasesinereaktiota. Alkuvaiheessa todettiin lievä tulehdus, joka ei vaadi antibioottihoitoa. Leikkaustekniikka on kirurgille verrattain helppo omaksua ja potilaalle turvallinen. Merkittäviä leikkauskomplikaatioita ei esiintynyt, myös leikkauksen jälkeinen haitta siirteen ottokohdalla on vähäinen. Äänitulokset olivat hyvät kaikissa tutkimuksissa, joskin pitkän seuranta-ajan (3-10 v.) tuloksissa oli enemmän vaihtelevuutta. Johtopäätös tästä oli että injektiotekniikka faskialla ei ole käyttökelpoinen vaikeimmissa hermovammoissa. Tulostemme perusteella faskiainjektio on käyttökelpoinen ja turvallinen äänihuulihalvauksen kirurginen hoito, joka soveltuu parhaiten lievien ja keskivaikeiden hermovammojen aiheuttaman käheyden korjaamiseen. Se tarjoaa äänikirurgille uuden käytännöllisen tekniikan tämän monimuotoisen ja usein vaikeahoitoisen vamman korjaamiseksi

High Resolution Multi-parametric Diagnostics and Therapy of Atrial Fibrillation: Chasing Arrhythmia Vulnerabilities in the Spatial Domain

After a century of research, atrial fibrillation (AF) remains a challenging disease to study and exceptionally resilient to treatment. Unfortunately, AF is becoming a massive burden on the health care system with an increasing population of susceptible elderly patients and expensive unreliable treatment options. Pharmacological therapies continue to be disappointingly ineffective or are hampered by side effects due to the ubiquitous nature of ion channel targets throughout the body. Ablative therapy for atrial tachyarrhythmias is growing in acceptance. However, ablation procedures can be complex, leading to varying levels of recurrence, and have a number of serious risks. The high recurrence rate could be due to the difficulty of accurately predicting where to draw the ablation lines in order to target the pathophysiology that initiates and maintains the arrhythmia or an inability to distinguish sub-populations of patients who would respond well to such treatments. There are electrical cardioversion options but there is not a practical implanted deployment of this strategy. Under the current bioelectric therapy paradigm there is a trade-off between efficacy and the pain and risk of myocardial damage, all of which are positively correlated with shock strength. Contrary to ventricular fibrillation, pain becomes a significant concern for electrical defibrillation of AF due to the fact that a patient is conscious when experiencing the arrhythmia. Limiting the risk of myocardial injury is key for both forms of fibrillation. In this project we aim to address the limitations of current electrotherapy by diverging from traditional single shock protocols. We seek to further clarify the dynamics of arrhythmia drivers in space and to target therapy in both the temporal and spatial domain; ultimately culminating in the design of physiologically guided applied energy protocols. In an effort to provide further characterization of the organization of AF, we used transillumination optical mapping to evaluate the presence of three-dimensional electrical substrate variations within the transmural wall during acutely induced episodes of AF. The results of this study suggest that transmural propagation may play a role in AF maintenance mechanisms, with a demonstrated range of discordance between the epicardial and endocardial dynamic propagation patterns. After confirming the presence of epi-endo dyssynchrony in multiple animal models, we further investigated the anatomical structure to look for regional trends in transmural fiber orientation that could help explain the spectrum of observed patterns. Simultaneously, we designed and optimized a multi-stage, multi-path defibrillation paradigm that can be tailored to individual AF frequency content in the spatial and temporal domain. These studies continue to drive down the defibrillation threshold of electrotherapies in an attempt to achieve a pain-free AF defibrillation solution. Finally, we designed and characterized a novel platform of stretchable electronics that provide instrumented membranes across the epicardial surface or implanted within the transmural wall to provide physiological feedback during electrotherapy beyond just the electrical state of the tissue. By combining a spatial analysis of the arrhythmia drivers, the energy delivered and the resulting damage, we hope to enhance the biophysical understanding of AF electrical cardioversion and xiii design an ideal targeted energy delivery protocol to improve upon all limitations of current electrotherapy

The genes must flow: using movement ecology to understand connectivity of Mojave desert tortoise (Gopherus agassizii) populations in altered landscapes

Maintaining historic connectivity across animal populations is important to ensure a species can persist into the future. Human infrastructure and activities often fragment habitat, so understanding how connectivity functions is important in mitigation efforts. Connectivity arises from the movement of individuals within and between populations; understanding the movement ecology of a species can provide crucial information in how to best manage populations to maintain gene flow across a landscape. The Mojave desert tortoise (Gopherus agassizii) is a threatened species of the southwestern United States that historically had range-wide genetic connectivity. Human activity has and continues to alter and fragment tortoise habitat and maintaining/restoring connectivity across the range has been identified as an important conservation goal. In this work, I study the movement ecology of Mojave desert tortoises to understand how natural and anthropogenic features contribute to patterns of connectivity in the species. Corridors are important areas of a landscape that allow movement of animals between population centers through areas of unsuitable habitat. Due to assumed modest dispersal capabilities of the species, tortoises have been classified as corridor-dwellers that primarily rely on overlapping home ranges within an area for gene flow through a corridor. I studied tortoise movement selection and home ranges to understand what delineates both natural corridors through mountain passes and artificial corridors of suitable habitat left on the landscape after construction of utility-scale solar installations. Tortoises avoided areas of high slope and low perennial vegetation cover, avoided moving near low-density roads, and traveled along linear barriers. Results suggested that corridors through mountain passes can function differently in allowing tortoise movement, supporting prior findings using genetic differences. Artificial corridors created with fencing may not function the same way as natural corridors as a result of alteration of movement behavior. Although tortoises will avoid certain features such as roads, they will still interact with them. To better understand how anthropogenic and natural features alter tortoise movement behavior, I studied fine-scale tortoise movements using Hidden Markov movement models. My findings suggested that tortoises may respond to the same anthropogenic features (e.g. paved roads) differently depending on the context. Tortoises also alter movement in disturbed areas such as those with off-highway vehicle recreation or wildfire scars, suggesting that these disturbances degrade tortoise habitat. Using simulations of tortoise movement, I show that the behavioral responses to these disturbances may alter how tortoises are distributed on the landscape. Describing the long-term space use of individuals is key to understanding how genetic information flows across the landscape. Using historic and contemporary telemetry datasets (4,861 years of data from 950 tortoises), I related long-term site fidelity and dispersal in desert tortoises to intrinsic (size and sex) and extrinsic (seasonal precipitation) covariates. Tortoises display high site fidelity, though this fidelity is altered by seasonal precipitation and sex. Dispersal is more likely to occur in smaller tortoises and in years with high winter but low summer precipitation or years with low winter but high summer precipitation. I forecast future connectivity across the Ivanpah valley area with an agent-based model to estimate how future precipitation may influence connectivity by altering dispersal propensity. I found no differences in connectivity across emission scenarios, though other anthropogenic stressors will likely play a role in the future of connectivity in this species. This work provides insight into how tortoise movement at different spatial and temporal scales interact with habitat features and disturbances to alter connectivity of tortoise populations

Video Kinematic Evaluation: new insights on the cardiac mechanical function

The cardiac mechanical function plays a critical role in governing and regulating its performance under both normal and pathological conditions. The left ventricle has historically received more attention in both congenital and acquired heart diseases and was considered as the mainstay of normal hemodynamics. However, over the past few decades, there has been increasing recognition of the pivotal role of the right ventricle in determining functional performance status and prognosis in multiple conditions. Nonetheless, the ventricles should not be considered separately as they share the septum, are encircled with common myocardial fibers and are surrounded by the pericardium. Thus, changes in the filling of one ventricle may alter the mechanical function of its counterpart. This ventricular interdependence remains even after the removal of the pericardium because of constrictive pericarditis or during open chest surgery. Interestingly, during open chest surgery, only the right ventricle mechanical activity is visually checked by the surgeon and cardiologist due to the absence of an intraoperative imaging technique able to evaluate its complex function. Noteworthy, most of the imaging techniques available to clinicians are established for the assessment of the left ventricle, with the ejection fraction being the most used parameter. However, this value is a measure of global systolic function which comes short in identifying regional myocardial impairment and the mechanical contraction. Therefore, new approaches are needed to deeply investigate the mechanics of both ventricles and correctly assess the cardiac mechanical performance. In this thesis, I studied the mechanical function of the left ventricle through different modalities of cardiac magnetic resonance and employed an innovative imaging technique for the assessment of the right ventricle mechanical function during open chest surgery

High School Mathematics Teachers\u27 Positioning within the Culture Of Blame: A Case Study

Overemphasis on high-stakes testing in mathematics, particularly in schools with economically disadvantaged students, has led to the formation of a culture of blame (Lau, 2009) and inconsistent instructional practices (Kitchen, Ridder, & Bolz, 2016). However, there are teachers who have been successful at ensuring deep mathematics learning takes place in spite of the demands of high-stakes testing instruction (Ladson-Billings, 2009; Leonard & Martin, 2013). The purpose of this study was to explore how high school mathematics teachers position themselves within the culture of blame that is manifested in the high-stakes testing environment. This qualitative holistic, multiple-case study was guided by the following research questions: In what ways do mathematics teachers position themselves within a culture of blame in ways that they can support student learning? The sub-questions that supported the overarching research question are: How do high school mathematics teachers position themselves within a culture of teacher blame and how does the culture of blame affect the creation and attainment of student learning goals? Data collection included surveys, a two-hour group interview of four participants, six, hour-long individual interviews, the collection of participant-provided artifacts, and artifacts collected from DuBois High Schools and Clinton County Public Schools. Positioning theory was used as the lens through which I examined the data. Findings suggest that teachers’ instructional decisions are highly influenced by high-stakes testing and that the culture of blame created by the overemphasis on test scores. Although the DuBois High School mathematics department fosters a community of care for their students, it is not enough to overcome the misalignment with the school administrators’ goals for their students

Movement and migration ecology of Alaskan golden eagles

Thesis (Ph.D.) University of Alaska Fairbanks, 2020Golden eagles Aquila chrysaetos are distributed across the Holarctic; however, in Alaska and other northern areas, many are long-distance migrants. Being soaring birds, golden eagles can use weather and features of the energy landscape to offset the energetic costs of movement and migration. In this dissertation, I investigate how dynamic energy landscapes, in addition to other habitat and anthropogenic features, affect the movement and migration ecology of Alaskan golden eagles; in most cases I did such by developing and applying new, biologically-appropriate statistical methods. First, I identified a single, discrete navigation decision that each eagle made during migration and determined which weather variables are primary factors in driving that decision. I found that wind was the primary correlate to the decision, consistent with eagles likely avoiding poor migration conditions and choosing routes based on favorable wind conditions. Second, I investigated how different forms of flight subsidies, which were orographic uplift, thermal uplift, and wind support, drove behavioral budgets and migratory pacing of eagles. I found a consistent daily rhythm in eagle behavior and migratory pace, seemingly driven by daily development of thermal uplift, with extended periods of slower-paced movements, consistent with periods of opportunistic foraging. Third, I investigated the effects of anthropogenic linear features, such as roads and railroads, on eagle movement during migration. I found that eagles selected for roads during spring migration and were more likely to be near roads when making slower-paced movements, which would be most frequent during times when limited thermal uplift is available. Lastly, I compared how floaters (breeding-age, non-territorial individuals) and territorial eagles used space and selected for resources, specifically interested in how their movements and space use might overlap. I found that floater space use was much more expansive, yet they only selected for habitats and resources slightly differently than territorial eagles. I also found their home ranges overlap substantially, suggesting that floaters play a key role in the population ecology of migratory golden eagles in Alaska.Alaska Department of Fish and Game, State Wildlife Grant Program, Calvin J. Lensink Fund, Institute of Arctic Biology, UAF Graduate SchoolChapter 1: Introduction -- Chapter 2: Local meteorological conditions reroute a migration -- Chapter 3: Dynamic-parameter movement models reveal drivers of migratory pace in a soaring bird -- Chapter 4: Novel step selection analyses on energy landscapes reveal how linear features alter migrations of soaring birds -- Chapter 5: Differential resource selection between territorial and floater golden eagles revealed with an Ornstein-Ulhenbeck space use model -- Chapter 6: Conclusion -- Appendix

Intertextuality and Identity: An Examination of Dramaturgy for Dance Through the Remounting Process

This research thesis focuses on remounting existing dance choreographies. It reveals a shift from traditional notions of the choreographer as a figure of centralized authority to a decentralized model of collaborative exploration. Questions raised throughout this investigation are: How are the outcomes of choreographic remounting affected by defining the place of imitation in the process? How can the artist's creative voice remain present and active in the context of executing already established choreography? What is the place of the dancer's adaptive choices, and how do they manifest in the remounting process and subsequent performance of the work? Three phases are identified in order to contextualize these questions within the remounting process. The three phases are: Mimesis, Embodiment and Interpretation. The theoretical framework for this study comes from dance and performance studies, using references from Mark Franko, Bojana Cvejic, and William Forsythe

Anyone Got My Time?: A Cross-Section Autobiography

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