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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Development and validation of a system for clinical assessment of gait cycle parameter in patients with idiopathic normal pressure hydocephalus / Utveckling och validering av ett system för klinisk bedömning av gångcykelns parametrar hos patienter med idiopatisk normaltrycks hydrocephalus

Bäcklund, Tomas January 2013 (has links)
A number of parameters have been identified as characteristic of the walking pattern in patients with INPH. Most of these have been identified through qualitative surveys and manually conducted test batteries. In order to obtain quantitative, standardized and objective measures, which enable studies based on larger patient populations and comparable results, there is a need for a user-friendly system that can measure specific key parameters over time in a reliable manner in everyday clinical work. Step height, width and the variability in the gait cycle are such parameters which are interesting research areas for this group of patient. Problems with balance and gait are very common in other patient groups as well, particularly in neurological diseases such as Parkinson's disease, multiple sclerosis and stroke. This is the reason that the development of this gait analyzer is performed. Giving access to a simple and objective method for estimating gait and balance ability in clinical routine investigations would increase the ability to provide the right kind of treatment, confirm treatment results, and conducting larger research studies. Therefore, this equipment can contribute to the assessment of diseases which contain impaired gait. As a first test of the usability and for the validation of accuracy and repeatability of the equipment a group of healthy volunteers was used. Results from tests on healthy subjects show god repeatability between measurements, for step width at normal gait the difference was -0,2 ±0,34 cm (mean, ±SD) and step height 0,69 ±3,34 cm. The stride time variability in the healthy group where very small 0,00048 ±0,00028 s2 with a difference between test of 0,000019 ±0,00038 s2. Three pilot patients have been tested where we have clearly seen indications of increased stride time variability and reduced step height.
22

Variability Among Individual Male Runners Influences Cumulative Loading More Than Foot Strike Type

Trotter, Tamarie 26 June 2023 (has links) (PDF)
Foot strike type affects running mechanics and may influence overuse injury occurrence. Measuring the interaction between cumulative load and foot strike type may provide additional information that could eventually help with understanding injury mechanisms. The purpose of this study was to determine how foot strike type affects cumulative loading in runners, and to determine if individual metrics change throughout a 5-kilometer sub-maximal run. 30 participants ran on an instrumented treadmill for 5 km at 3.15 m/s with their preferred foot strike type (14 rearfoot strike, 16 non-rearfoot strike). Stride rate, foot strike angle, loading rate, per stride and per km (cumulative) vertical ground reaction force impulse, impact peak, absolute peak, knee negative work, and ankle negative work were calculated and compared across time and between groups. Per stride between-group main effects were seen for stance time (p=0.003), foot strike angle (p<0.001), and loading rate (p=0.040), all of which were greater for rearfoot strike runners. Per stride and cumulative ankle and knee negative work also showed significant differences, with ankle negative work being greater for non-rearfoot strike runners (p=<0.001 per stride, p=<0.001 cumulative) and knee negative work being greater for rearfoot strike runners (p=0.014 per stride, p=0.008 cumulative). Both loading rate and cumulative vertical ground reaction force impulse decreased significantly over time (p=0.035, p=<0.001 respectively). In summary, we found a few differences in per stride and cumulative metrics between foot strike groups, namely ankle and knee loading as previously observed. However, as a whole, individual variability in vertical ground reaction force loading patterns was more apparent than any group distinctions. We also found patterns in previous research suggesting that study design components, specifically self-selected speed and habituation, affect variables such as stride rate and peak vertical ground reaction force. The common perception that non-rearfoot strike runners have a higher stride rate was not supported in this study. Lastly, we determined that cumulative calculations can be different if taken at the beginning vs the end of a run. Quantifying injury risk is complicated and cumulative damage models should take into account individual load capacity and training session characteristics (e.g., warm-up time, length, intensity, and rest time).
23

A Biomechanical Analysis of Sprinters vs. Distance Runners at Equal and Maximal Speeds

Bushnell, Tyler D. 02 December 2004 (has links) (PDF)
In the sport of track and field, sprinting and distance running represent two major categories of athletes. Sprinting is associated with power and speed, whereas distance running focuses on the economy of movement. With distance running there are elements of sprint technique that overlap. With distance events, there comes a time near the end of the race where economy gives way to speed. If the distance runners knew how to alter their technique in a way to become more sprint-like, this process could possibly be more successful. PURPOSE: This study compared the differences in technique between sprinters and distance runners while running at equal and maximal speeds. METHODS: Subjects for the study consisted of 10 Division I collegiate distance runners, 10 Division I collegiate sprinters, and 10 healthy non-runners. The subjects performed two tests, with each consisting of a 60 meter run completed on the track. Test 1 was run at a pace of 5.81 m/s (4:37 min/mile), while Test 2 was completed at maximal speed. Video footage of each trial was collected at 180 Hz, monitoring hip, knee, thigh, and shank positions, as well as stride length, and contact time. RESULTS: Significant differences (p < .05) between the sprint and distance groups at maximal speed were found in the following areas: speed, minimum hip angle, knee extension at toe-off, stride length, contact time, and the position of the recovery knee at touchdown. Sprinters and distance runners exhibited a significantly lower minimum knee angle than those in the control group. Significant differences between the sprint and control group existed at the minimum hip angle, speed, stride length, contact time, and the position of the recovery knee at touchdown. Regarding the paced trial, the sprinters and distance runners showed significant difference concerning the minimum hip angle, center of mass at touchdown, and recovery knee at touchdown. Sprinters differed significantly from the control group in contact time, the center of mass at touchdown and the position of the recovery knee at touchdown. CONCLUSION: As distance runners attempt to sprint, the desired adaptations do not necessarily occur. The development of economical distance form is a fairly natural process that occurs with the miles of training. Sprinting, however, is a separate, learned technique that often requires specific feedback. When attempting maximal speed, distance runners may benefit by focusing on one characteristic of technique. If knee extension at toe-off could be trained to become more sprint-like, the other characteristics unique to sprinters may follow.
24

Securing cloud-hosted IoT Workflows with Intel SGX

Jamil Ahsan, Adnan January 2022 (has links)
The rapid increase in the number of IoT devices and their widespread applications demands secure and scalable solutions for managing and executing IoT workflows. This thesis investigates the security of IoT workflows created in Node-RED, an open-source visual programming tool, and deployed on untrusted hosts managed by a major cloud service provider, Azure. The hypothesis was that the security of IoT workflows could be improved by utilizing a trusted execution environment, such as Intel SGX. Additionally, an assessment of consequent performance degradation was proposed. A threat model for an IoT workflow system scenario was established using the STRIDE threat modeling framework. An evaluation of the security guarantees provided by the prototype system was performed using an analysis comparing the security guarantees of underlying technologies, predominantly Intel SGX, and aggregating them to establish the security promises of the final system. The performance evaluation of the system was conducted using a set of experimental workflows, executed both natively on Linux and inside Intel SGX. The proposed prototype system was deemed to be capable of mitigating 15 out of 18 potential threats defined in the threat model, which indicates a significant threat risk reduction. However, the added security resulted in degraded performance, which was considerable when executing system calls and significantly noticeable for workflows requiring multi-threading. The results showed that node execution time inside SGX was 4.8 times slower and the mean round trip time for workflow execution was 6 times slower than the native execution. The thesis aims to provide a starting point for estimating performance degradation for potential future applications requiring secure IoT workflow deployment on untrusted hosts. / Den snabba ökningen av antalet IoT-enheter i dagens samhälle och deras breda användningsområden kräver säkra och skalbara lösningar för exekvering av IoT-arbetsflöden. Detta examensarbete undersöker säkerheten för IoT-arbetsflöden skapade i Node-RED, ett öppen källkodsverktyg för visuell programmering, i kontexten att dessa arbetsflöden exekveras på opålitliga enheter som hanteras av molntjänstföretag, som i detta fall är Azure. Hypotesen var att säkerhetsgarantin för IoT-arbetsflöden kunde förbättras genom att använda en betrodd exekveringmiljö, såsom Intel SGX. Dessutom krävdes en utvärdering av påföljderna på systemets prestanda som en konsekvens av den betrodda exekveringmiljöns användning. En hotmodell för ett IoT-arbetsflödesystem etablerades med hjälp av ramverket STRIDE. En bedömning av säkerhetsgarantierna som tillhandahålls av prototypsystemet genomfördes med hjälp av en kvalitativ analys som jämförde säkerhetsgarantier för underliggande teknologier, främst Intel SGX, och aggregerade dessa för att etablera säkerhetsgarantin för det slutgiltiga systemet. Prestandautvärderingen av systemet genomfördes med hjälp av ett antal experimentella arbetsflöden, som exekverades både direkt på Linux och inuti den betrodda exekveringsmiljön Intel SGX. I det föreslagna prototypsystemet ansågs 15 utav 18 potentiella hot som definierats i hotmodellen vara försumbara, vilket indikerar en signifikant reduktion av hotbilden. Dock resulterade den ökade säkerheten i en försämrad prestanda, som var betydande när systemanrop användes och synnerligen märkbar för flöden som krävde parallellisering. Resultaten visade att nodexekveringstiden inuti SGX var 4,8 gånger långsammare och medelvärdet för rundturstiden för exekvering av ett arbetsflöde var 6 gånger långsammare än den direkta exekveringen. Examensarbetet syftar till att ge en utgångspunkt för att bedöma prestandaförsämringen för potentiella framtida applikationer som kräver säkra IoT-arbetsflöden exekverade på opålitliga enheter.
25

The Effect of Bodyweight Support on Stride Frequency Self-Optimization Capacity in Female Novice Runners

Park, Joshua M. 16 September 2022 (has links)
No description available.
26

Nástroj pro podporu analýzy rizik v informační bezpečnosti / Tool for Risk Analysis Support in Information Security

Plíšek, Martin January 2012 (has links)
The master thesis deals with the development of the tool for risk analysis support in information security. At first we perform a theoretical basis for security development of lifecycle process (SDL). Afterwards the theory of risk analysis based on fault tree analysis is described. Considering this knowledge base system was designed and implemented. Next chapter describes the best practice refer to the typical example of use and presents the potencial using of this tool in practice. Final chapter deals with the possibility of future expansion of this application.
27

StrideLang : Creation of a Domain-Specific Threat Modeling Language using STRIDE, DREAD and MAL / StrideLang : Skapandet av ett Domän-Specifikt Hotmodellerings-Språk med STRIDE, DREAD och MAL

Cerovic, Lazar January 2022 (has links)
Cybersecurity is still one of the main challenges of the digital era for organizations and individuals alike. Threat modeling is an important tool for building systems that are reliable and secure. The research question for this study is to create a domain specific language (DSL) with the Meta Attack Language (MAL), STRIDE and DREAD. One of the main challenges is to choose a DSL that is suitable for threat modeling. The purpose of the study is to provide people with threat modeling with additional tools that can be used in attack simulations. MAL is a meta language used for creating DSL that can be used for attack simulations. An example of a MAL project that usually serves as a template for other DSL is coreLang, which models the general IT infrastructure. STRIDE is a model used in threat modeling to enumerate and categorization of cyberthreats. DREAD is a model used for risk assessment that scores each threat by a value between one and ten. The proposed method for answering the research question is the Design Research Science Method (DRSM), which is often used for creating artifacts. Evaluation of the results is done with tests written in Java using the Junit framework. The result of the study is the creation of strideLang that maps attack steps in coreLang (MAL implementation of the general IT infrastructure DSL) to STRIDE and DREAD models. The primary source of error in the investigation is the risk assessment with DREAD, which can be somewhat inaccurate depending on what specific DSL is used. It would have been valuable if the study incorporated feedback from domain experts specifically with risk assessment. The nature of the STRIDE and DREAD models is that the models are very subjective in practice. However, this study does provide insights in how a DSL can be created based on DREAD and STRIDE. Future work might investigate a different DSL, incorporate tools such as SecuriCAD and compare different threat models. / Cybersäkerhet är fortfarande en av de främsta utmaningarna i den digitala eran för såväl organisationer som individer. Hotmodellering är ett viktigt verktyg för att bygga tillförlitliga och säkra system. Huvudmålet för denna studie är att skapa ett domänspecifikt språk (DSL) med Meta Attack Language (MAL), STRIDE och DREAD. En av de främsta utmaningarna för att nå målet med studien är att hitta ett domänspecifikt språk som är lämpligt för denna typ av hotmodellering. Syftet med studien är att förse personer som arbetar med hotmodellering med ytterligare verktyg för att kunna använda i sina attacksimuleringar. MAL är ett metaspråk som används för att skapa domän-specifika språk och utföra attacksimuleringar. Ett exempel på ett MAL projekt som oftast används som en mall för att skapa nya domänspecifika och modellerar den generella IT infrastrukturen. STRIDE modellen används för att lista och kategorisera digitala hot. DREAD brukar användas tillsammans med STRIDE och används för att risk bedöma digitala hot genom att betygsätta hoten med ett värde mellan ett och tio. Den valda metoden för att lösa forskningsfrågan är Design Research Science Method (DSRM), som används oftast i samband med skapandet av artefakter. Evaluering av resultatet gjordes med tester skrivna i Java med ramverket JUnit. Studien resulterade med skapande av strideLang som mappar attack steg i coreLang till STRIDE och DREAD modellerna. Den främsta felkällan i denna studie är riskbedömningen med DREAD eftersom noggrannheten på riskbedömningen kan variera från specifika domän i IT infrastrukturen. Det hade varit värdefullt om studien integrera domänexperters bedömning i studien främst för DREAD bedömningen. STRIDE och DREAD modellerna är subjektiva vilket betyder att olika experter kan komma till olika slutsatser för samma hot. Däremot så kan studien förse med intressanta insikter om hur ett domän-specifikt språk kan skapas baserat på DREAD och STRIDE modellerna. Framtida studier kan undersöka en mer specifik domän inom IT infrastrukturen, integrera verktyg som SecuriCAD och jämföra olika modeller som används inom hotmodelleringen
28

Etisk hackning av en smart foderautomat / Ethical hacking of a Smart Automatic Feed Dispenser

Lokrantz, Julia January 2021 (has links)
Sakernas internet (IoT) syftar till det nät av enheter som samlar och delar data över internet. De senaste åren har användandet av konsument-IoT ökat explosionsartat och åtföljts av en ökad oro kring säkerheten i dessa enheter, då många system visat sig ha bristande säkerhetsimplementeringar. Denna studie undersöker säkerheten i en smart foderautomat för husdjur och redogör för ekonomiska orsaker till förekomsten av sårbarheter. Metoden bygger på att hotmodellera foderautomaten med STRIDE- och DREAD-modellerna följt av en penetrationstestningsfas för några av de allvarligaste hoten. Resultatet visar på att foderautomaten Trixie TX9 har otillräcklig kryptering av nätverksnamn och lösenord till Wi-Fi, är sårbar mot flödesattacker och att analys av trafiken till/från enheten kan avgöra vilket tillstånd den är i. Vidare har foderautomaten flera öppna nätverkstjänster, där bland annat en Telnettjänst som kan nås genom svaga, hårdkodade inloggningsuppgifter som finns publicerade på internet. Ekonomiska orsaker till förekomsten av sårbarheter är främst asymmetrisk information och motstridande incitament. Det är idag svårt för tillverkare att ta betalt för säkerhet då marknaden drivs av snabba lanseringar och utökade funktioner till ett pressat pris. / Internet of things (IoT) refers to the web of connected devices that collect and share data through the internet. The use of consumer-IoT has increased dramatically in recent years, accompanying an increasing concern about the security of these devices as many systems have proven to have insufficient security measures. This study aims to investigate the security level of a smart food dispenser for pets, and account for the underlying economic reasons for the occurrences of vulnerabilities. The method used in this study consists of conducting threat modeling of the food dispenser using STRIDE as well as DREAD models. This is then followed by a penetration-testing phase for some of the more serious threats. The results indicate that the food-dispenser Trixie TX9 has insufficient encryption of network names and passwords, is susceptible to flooding-attacks, and analysis of the incoming/outgoing data traffic from the device can deduct which state it is currently in. Furthermore, the food dispenser has several open network services, Telnet is one among them, which can be accessed through weak, hardcoded credentials that are published on the internet. The economic reasons for these security weaknesses are asymmetrical information and misaligned economic incentives. Manufacturers struggle to charge consumers for an increased level of security as the main market driving factors are swift and regular product launches as well as an expansion of new features available at competitively low prices.
29

Squats as a predictor of on-ice performance in ice hockey

Edman, Sebastian, Esping, Tobias January 2013 (has links)
Introduction: The National Hockey League Entry Draft Combine (NHLED Combine) is considered one of the toughest physical fitness tests an ice hockey player has to go through. The NHLED Combine consists of several fitness tests evaluating the athlete’s aerobic- and anaerobic capacity; lower body power, upper body strength and power, flexibility and anthropometrics; no lower body strength test are employed. Squats are the only exercise used by all National Hockey League (NHL) strength and conditioning coaches yet it is not included in the NHLED Combine. Purpose: The purpose of this study was to determine which off-ice test correlates best with on-ice performance measured as forward skating speed. We hypothesised that squat one repetition maximum (squat 1RM) would be a better or equal predictor of on-ice performance compared to the current NHLED Combine tests standing long jump (SLJ) and Wingate anaerobic test (WAnT). Method: Eleven male subjects, aged 17.8 ± 0.8 years, performed an on-ice sprint followed by the off-ice tests SLJ, WAnT and squat 1RM. Results: A correlation was found between sprint time on-ice and SLJ (r= -0,727, p= 0.006), Wingate anaerobic test mean power/ body weight (WAnT MP/BW) (r= -0,607, p= 0,024), squat 1RM (r= -0,600, p= 0.026) and squat 1 repetition maximum/body weight (squat 1RM/BW) (r= -0,609, p= 0.023). Conclusion: The results indicate that squat 1RM and squat 1RM/BW are equally good predictors of hockey performance as SLJ and WAnT MP/BW. / knäböj, hockey, is, nhl, skridskoåkning, skridskoskär, sprint, horisontalhopp, wingate, styrka, kraftutveckling, fystest
30

Software platform for gait evaluation using MATLAB and off-the-shelf MEMS sensors / Mjukvaruplattform för gånganalys med Matlab och kommersiella MEMS-sensorer

Svantesson, Oscar January 2013 (has links)
This thesis presents a real time software program written in MATLAB using off-the-self MEMS sensors from Shimmer-Research®. Parallel to the software development, a proof of concept was conducted using the produced program to quantify stride length, stride length variance and stride time for patients diagnosed with Parkinson's disease. Results from testing showed that the system measured the mean stride length error to 2.4% of stride length and a standard deviation of 13.7% of stride length. Results from testing further showed a stride time error of 2.70% of individual stride times with a standard deviation of 1.89%. The system shows promise as a pedagogical, gait analysis training tool for physiotherapists as well as in academic teaching. The system is flexible and data processing functions can be readily re-programmed with other or additional processing features while maintaining user feedback, storage and plotting functionalities implemented in the current version of the program.

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