Dissertations / Theses: 'Enid Twp'

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BONAM, VEERA VENKATA SIVARAMAKRISHNA. "Multipath TCP and Measuring end-to-end TCP Throughput : Multipath TCP Descriptions and Ways to Improve TCP Performance." Thesis, Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-17075.

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Internet applications make use of the services provided by a transport protocol, such as TCP (a reliable, in-order stream protocol). We use this term Transport Service to mean the end-to- end service provided to application by the transport layer. That service can only be provided correctly if information about the intended usage is supplied from the application. The application may determine this information at the design time, compile time, or run time, and it may include guidance on whether a feature is required, a preference by the application, or something in between. Multipath TCP (MPTCP) adds the capability of using multiple paths to a regular TCP session. Even though it is designed to be totally backward compatible to applications. The data transport differs compared to regular TCP, and there are several additional degrees of freedom that the particular application may want to exploit. Multipath TCP is particularly useful in the context of wireless networks using both Wi-Fi and a mobile network is a typical use case. In addition to the gains in throughput from inverse multiplexing, links may be added or dropped as the user moves in or out of coverage without disrupting the end-to-end TCP connection. The problem of link handover is thus solved by abstraction in the transport layer, without any special mechanisms at the network or link level. Handover functionality can then be implemented at the endpoints without requiring special functionality in the sub-networks according to the Internet's end-to-end principle. Multipath TCP can balance a single TCP connection across multiple interfaces and reach very high throughput.

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Afifi, Mohammed Ahmed Melegy Mohammed. "TCP FTAT (Fast Transmit Adaptive Transmission): A New End-To- End Congestion Control Algorithm." Cleveland State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=csu1414689425.

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SANA, VINEESHA. "Multipath TCP and Measuring endto-end TCP Throughput : Measuring TCP Metrics and ways to improve TCP Throughput performance." Thesis, Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-17098.

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Internet applications make use of the services provided by a transport protocol, such as TCP (a reliable, in-order stream protocol). We use the term Transport Service to mean the endtoend service provided to application by the transport layer. That service can only be provided correctly if information about the intended usage is supplied from the application. The application may determine this information at the design time, compile time, or run time, and it may include guidance on whether a feature is required, a preference by the application, or something in between. Multipath TCP (MPTCP) adds the capability of using multiple paths to a regular TCP session. Even though it is designed to be totally backward compatible to applications. The data transport differs compared to regular TCP, and there are several additional degrees of freedom that the particular application may want to exploit. Multipath TCP is particularly useful in the context of wireless networks using both Wi-Fi and a mobile network is a typical use case. In addition to the gains in throughput from inverse multiplexing, links may be added or dropped as the user moves in or out of coverage without disrupting the end-to-end TCP connection. The problem of link handover is thus solved by abstraction in the transport layer, without any special mechanisms at the network or link level. Handover functionality can then be implemented at the endpoints without requiring special functionality in the sub-networks according to the Internet's end-to-end principle. Multipath TCP can balance a single TCP connection across multiple interfaces and reach very high throughput.

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Prasad, Ravi S. "An evolutionary approach to improve end-to-end performance in TCP/IP networks." Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22543.

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Despite the persistent change and growth that characterizes the Internet, the Transmission Control Protocol (TCP) still dominates at the transport layer, carrying more than 90\% of the global traffic. Despite its astonishing success, it has been observed that TCP can cause poor end-to-end performance, especially for large transfers and in network paths with high bandwidth-delay product. In this thesis, we focus on mechanisms that can address key problems in TCP performance, without any modification in the protocol itself. This evolutionary approach is important in practice, as the deployment of clean-slate transport protocols in the Internet has been proved to be extremely difficult. Specifically, we identify a number of TCP-related problems that can cause poor end-to-end performance. These problems include poorly dimensioned socket buffer sizes at the end-hosts, suboptimal buffer sizing at routers and switches, and congestion unresponsive TCP traffic aggregates. We propose solutions that can address these issues, without any modification to TCP.

In network paths with significant available bandwidth, increasing the TCP window till observing loss can result in much lower throughput than the path's available bandwidth. We show that changes in TCP are {em not required} to utilize all the available bandwidth, and propose the application-layer SOcket Buffer Auto-Sizing (SOBAS) mechanism to achieve this goal. SOBAS relies on run-time estimation of the round trip time (RTT) and receive rate, and limits its socket buffer size when the receive rate approaches the path's available bandwidth. In a congested network, SOBAS does not limit its socket buffer size. Our experiment results show that SOBAS improves TCP throughput in uncongested network without hurting TCP performance in congested networks.

Improper router buffer sizing can also result in poor TCP throughput. Previous research in router buffer sizing focused on network performance metrics such as link utilization or loss rate. Instead, we focus on the impact of buffer sizing on end-to-end TCP performance. We find that the router buffer size that optimizes TCP throughput is largely determined by the link's output to input capacity ratio. If that ratio is larger than one, the loss rate drops exponentially with the buffer size and the optimal buffer size is close to zero. Otherwise, if the output to input capacity ratio is lower than one, the loss rate follows a power-law reduction with the buffer size and significant buffering is needed. The amount of buffering required in this case depends on whether most flows end in the slow-start phase or in the congestion avoidance phase.

TCP throughput also depends on whether the cross-traffic reduces its send rate upon congestion. We define this cross-traffic property as {em congestion responsiveness}. Since the majority of Internet traffic uses TCP, which reduces its send rate upon congestion, an aggregate of many TCP flows is believed to be congestion responsive. Here, we show that the congestion responsiveness of aggregate traffic also depends on the flow arrival process. If the flow arrival process follows an open-loop model, then even if the traffic consists exclusively of TCP transfers, the aggregate traffic can still be unresponsive to congestion. TCP flows that arrive in the network in a closed-loop manner are always congestion responsive, on the other hand. We also propose a scheme to estimate the fraction of traffic that follows the closed-loop model in a given link, and give practical guidelines to increase that fraction with simple application-layer modifications.

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Cho, Sung Rae. "An end-to-end freeze TCP for ad-hoc networks." Thesis, University of Canterbury. Electrical Engineering, 2004. http://hdl.handle.net/10092/9606.

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SACK TCP, as the baseline, performs promisingly in the wireline network where major control point is of the network buffer utilization. Basically, the reactive based congestion window progression causes high network buffer utilization due to the likelihood of large bursts of data, and it deteriorates the network bandwidth utilization: the resultant end-to-end RTT inflation results in large retransmission timouts (RTOs), thus long timeouts, and reduced TCP throughput. In this thesis, we have evaluated that through a series of simulations performed in ns-2, the baseline, of such large bursts of data transfer and the resultant large RTOs, is not suited for ad hoc networks in terms of power and badwidth limitations. We investigated a receiver-oriented rate controller (rater) dominated by the resource-constraint ad hoc links, where the link availability changes not gracefully but transiently. Assuming that end clocks are both synchronized in a passive or active way and TCP takes into account the TTL field of the IP header each time when data packet is received, the forward link delay (FLD) and the current hop length give the instantaneous throughput available. Then, in order to throttle the sender congestion window by using the advertised window field, the receiver employs the congestion window delimiter that is characterized by the 802.11 MAC protocol. In addition, the transient nature of the medium availability due to medium contention proposes the freezing timer (freezer) to be equipped at the receiver-end that periodically freezes the sender in cases of heavy contention present. In this sense, two other metrics, i.e., buffer occupancy and contention factor have been introduced to perceive the degree of the buffer utilization and the medium contention, respectively, for supporting the delimiter and the freezer. Finally, an elaborate sender-end, namely ad hoc sender enhancements, was proposed for achieving the optimized behaviors of the receiver-end enhancements, as an optional deployment. It implemented an add-on probing mechanim to deal with the route disconnection problem by means that the probing backoff supersedes the RTO backoff. The combination of the schemes, i.e., delimiter + freezer + ad hoc sender enhancements, is called the ad hoc TCP. It outperformed the baseline in perspective of both throughput and, especially, goodput. The primary merit of our ad hoc TCP is that such propositions are based on solely end-to-end, so do not require the network originated feedback.

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Wu, Chen. "A new TCP protocol based on end-to-end available bandwidth measurement /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20WU.

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Mutagahywa, Eric Beda. "Socketless TCP : a connection identification philosophy for end to end mobility." Master's thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/5147.

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Includes bibliographical references.
There is increasing pressure on Telecoms and Internet Service Providers to supply their customers with access to their customized services anywhere, on any terminal via any access technology. The pressure is trickled down to software programmers to provide innovative and advanced applications to fit this new environment. This will require network protocol architects to provide an Internet framework that will give programmers more control and flexibility to create mobile aware applications. To fulfill such requirements, network protocol architects need to shift their mobility perspective from the mobile terminal to a finer grained model; finely grained in respect to allowing individual transport connections to seamless switch between network terminals, controlled dynamically and/or manually by applications or users. The key issue of this vision is how to support this model in TCP/IP networks. We argue that the TCP/IP socket pair connection identification model restricts this granularity and flexibility of mobility. We present Socketless TCP (SL-TCP), an architectural concept based on reconsidering the socket pair for connection identification.

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Portelli, Rebecca. "CheesePi: Delay Characterization through TCP-based Analysis from End-to-End Monitoring." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194244.

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With increasing access to interconnected IP networks, people demand a faster response time from Internet services. Traffic from web browsing, the second most popular service, is particularly time-sensitive. This demands reliability and a guarantee of delivery with a good quality of service from ISPs. Additionally, the majority of the population do not have the technical background to monitor the delay themselves from their home networks, and their ISPs do not have a vantage point to monitor and diagnose network problems from the users’ perspective. Hence, the aim for this research was to characterise the “in-protocol” network delay encountered during web browsing from within a LAN. This research presents TCP traffic monitoring performed on a client device as well as TCP traffic monitoring over both the client-end and the server-end devices separately observing an automated web client/server communication. This was followed by offline analysis of the captured traces where each TCP flow was dissected into: handshake, data transfer, and teardown phases. The aim behind such extraction was to enable characterisation of network round-trip delay as well as network physical delay, end host processing delay, web transfer delay, and packets lost as perceived by the end hosts during data transfer. The outcome of measuring from both end devices showed that monitoring from both ends of a client/server communication results to a more accurate measurement of the genuine delay encountered when packets traverse the network than when measuring from the client-end only. Primarily, this was concluded through the ability to distinguish between the pure network delay and the kernel processing delay experienced during the TCP handshake and teardown. Secondly, it was confirmed that the two RTTs identified in a TCP handshake are not symmetrical and that a TCP teardown RTT takes longer than the TCP handshake RTT within the same TCP flow since a server must take measures to avoid SYN flooding attacks. Thirdly, by monitoring from both end devices, it was possible to identify routing path asymmetries by calculating the physical one-way delay a packet using the forward path in comparison to the physical delay of a packet using the reverse path. Lastly, by monitoring from both end devices, it is possible to distinguish between a packet that was actually lost and a packet that arrived with a higher delay than its subsequent packet during data transfer. Furthermore, utilizing TCP flows to measure the RTT delay excluding end host processing gave a better characterisation of the RTT delay as opposed to using ICMP traffic.
Med ökande tillgång till den sammankopplade IP-nätet, krävs det en snabbare responstid från Internettjänster. Trafik från surfning, den näst mest populära tjänsten är särskilt tidskänsliga. Detta kräver tillförlitlighet och en garanti för data leverans med en god servicekvalitet från Internetleverantörer. Dessutom har de flesta av befolkningen inte den tekniska bakgrunden för att övervaka fördröjning sig från sina hemmanätverk, och deras Internetleverantörer har ingen utsiktspunkt för att övervaka och diagnostisera nätverksproblem från användarnas perspektiv. Därför syftet med denna forskning är att karakterisera “in-protokoll” fördöljingen i nätet, som påträffas under surfning inifrån ett LAN. Denna forskning visar TCP-trafik monitoring som utförs på en klientenhet, samt separat TCP-trafik monitoring över både klient-end och serve-end enheter, för att observera en automatiserad webbklient / server-kommunikation. Detta följs av offline analys av de infångade tracer där varje TCP flöde dissekerades in: handskakning, dataöverföring, och nedkoppling faser. Syftet bakom sådan utvinning är att möjliggöra karakterisering av nätverk fördröjning samt nätverkets fysiska fördröjning, behandlingsfördröjning, webböverföringsfördröjning och förlorade paket som uppfattas av end-device under dataöverföring. The outcome of measuring from both end devices showed that monitoring from both ends of a client/server communication results to a more accurate measurement of the genuine delay encountered when packets traverse the network than when measuring from the client-end only. Primarily, this was concluded through the ability to distinguish between the pure network delay and the kernel processing delay experienced during the TCP handshake and teardown. Secondly, it was confirmed that the two RTTs identified in a TCP handshake are not symmetrical and that a TCP teardown RTT takes longer than the TCP handshake RTT within the same TCP flow since a server must take measures to avoid SYN flooding attacks. Thirdly, by monitoring from both end devices, it was possible to identify routing path asymmetries by calculating the physical one-way delay a packet using the forward path in comparison to the physical delay of a packet using the reverse path. Lastly, by monitoring from both end devices, it is possible to distinguish between a packet that was actually lost and a packet that arrived with a higher delay than its subsequent packet during data transfer. Furthermore, utilizing TCP flows to measure the RTT delay excluding end host processing gave a better characterisation of the RTT delay as opposed to using ICMP traffic. Resultatet av mätningarna från både slut-enheter visar att övervakning från båda ändar av en klient / server-kommunikation resulterar en noggrannare mätning av fördröjningar som uppstår när paketen färdas över nätverket än vid mätning från den enda klienten. Främst avslutades detta genom förmågan att skilja mellan den rena nätfördröjningen och kernel bearbetning under TCP handskakning och nedkoppling. För det andra bekräftades att de två RTT som identifierats i en TCP handskakning inte är symmetriska och att TCP nedkoppling RTT är längre än TCP handskakning RTT inom samma TCP flödet, eftersom servern måste vidta åtgärder för att undvika SYN översvämning attacker. För det tredje, genom att övervaka från båda avancerade enheter, var det möjligt att identifiera path asymmetrier genom att beräkna den fysiska envägsfördröjningen av ett paket på framåtriktade banan i jämförelse med den fysiska fördröjningen för ett paket på den omvända banan. Slutligen genom att övervaka från båda end enheter, är det möjligt att skilja mellan ett paket som faktiskt förlorades och ett paket som kom med en högre fördröjning än dess efterföljande paket under dataöverföring. Dessutom utnyttjande av TCP flöden för att mäta RTT exkluderat end-nod porocessering gav en bättre karakterisering av RTT fördröjning jämfört med att ICMP-trafik.

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Lau, Chee Kong Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Improving mobile IP handover latency on end-to -end TCP in UMTS/WCDMA networks." Awarded by:University of New South Wales. School of Electrical Engineering and Telecommunications, 2006. http://handle.unsw.edu.au/1959.4/22806.

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Due to terminal mobility and change of service area, efficient IP mobility support is an important aspect in UMTS networks in order to provide mobile users negligible packet loss rate and low handover latency, and thus some level of guaranteed quality-ofservice (QoS) to support real-time applications. 3G/UMTS has been specified and implemented as an end-to-end mobile communications system. The underlying WCDMA access systems manage radio access handover (layer 1) and provide linklayer mobility (layer 2) in terms of connection setup and resource management. For the UMTS nodes to have seamless connectivity with the Internet, the UMTS core networks need to be able to support continuous and no network service session handover (layer 3 and above). A long IP handover latency results in high packet loss rate and severely degrades its end-to-end transport level performance. Network-layer handover latency has therefore been regarded as one of the fundamental limitations in IP-based UMTS networks. Therefore, it is crucial to provide efficient network-layer mobility management in UMTS/WCDMA networks for seamless end-to-end TCP connection with the global Internet. Mobility of UMTS nodes necessitates extra functionalities such as user location tracking, address registration and handover related mechanisms. The challenge to provide seamless mobility in UMTS requires localised location management and efficient IP handover management. Mobile IPv6 protocol offers a better mobility support as the extended IPv6 features with mobility mechanism are integrated to the mobile nodes. To mitigate the effect of lengthy IP handover latency, two well-known handover reducing mechanisms based on Mobile IPv6 support have been proposed in the literature. They are designed with hierarchical network management and address pre-configuration mechanism. Hierarchical management aims to reduce the network registration time, and fast-handover attempts to minimise the address resolution delay. S-MIP (Seamless Mobile IP) integrates the key benefits of the above IP mobility mechanisms coupled with local retransmission scheme to achieve packet lossless and extremely low handover latency, operating in WLAN environments. In this thesis, we explore the possible Mobile IP solutions and various IP handover optimisation schemes in IPv6 to provide seamless mobility in UMTS with the global Internet. It aims at developing an optimised handover scheme that encompasses the packet lossless and extremely low handover latency scheme in S-MIP, and applying it into the UMTS/WCDMA packet data domain. Therefore, the hybrid UMTS-SMIP architecture is able to meet the requirements of delay sensitive real-time applications requiring strict delay bound, packet lossless and low handover latency performance for end-to-end TCP connection during a UMTS IP-based handover. The overall seamless handover architecture in UMTS facilitates integrated, scalable and flexible global IP handover solution enabling new services, assuring service quality and meeting the user???s expectations in future all-IP UMTS deployment. The viability of the seamless mobility scheme in UMTS is reflected through and validated in our design model, network protocol implementation, and service architecture. We illustrate the performance gained in QoS parameters, as a result of converged UMTS-SMIP framework compared to other Mobile IPv6 variants. The simulation results show such a viable and promising seamless handover scheme in UMTS on IP handover latency reduction on its end-to-end TCP connection.

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Craven, Ryan M. "Design and evaluation for the end-to-end detection of TCP/IP header manipulation." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42602.

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Approved for public release; distribution is unlimited
Understanding, measuring, and debugging IP networks, particularly across administrative domains, is challenging. One aspect of the challenge are transparent middleboxes, which are now common in today’s Internet. In-path middleboxes that modify packet headers are typically transparent to a TCP, yet can impact the end-to-end performance of its connections. Of equal importance, middleboxes cause architectural ossification that hinders network protocol evolution—new options or redefined header fields are often misconstrued, modified, or disabled. We develop TCP HICCUPS to reveal packet header manipulation to both endpoints of a TCP connection. HICCUPS adds a lightweight tamper-evident seal to TCP that is incrementally deployable and introduces no new options. HICCUPS provides an optional feature, AppSalt, that allows applications to request added protection for their connection’s integrity, making it more difficult for middleboxes to falsify integrity values. HICCUPS is implemented in both an operating system patch to the Linux TCP stack as well as a set of cross-platform user-space tools. To evaluate HICCUPS, we deploy it to a diverse set of Internet nodes spread across 197 networks and 48 countries, measuring packet header manipulations on over 26 thousand directed port/path pairs. We discover over 11 thousand instances of unique non-NAT in-path packet header modifications across those flows, all with the potential to negatively affect TCP performance.

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Alnuem, M. A. "Improving TCP performance over heterogeneous networks : the investigation and design of End to End techniques for improving TCP performance for transmission errors over heterogeneous data networks." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/3347.

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Transmission Control Protocol (TCP) is considered one of the most important protocols in the Internet. An important mechanism in TCP is the congestion control mechanism which controls TCP sending rate and makes TCP react to congestion signals. Nowadays in heterogeneous networks, TCP may work in networks with some links that have lossy nature (wireless networks for example). TCP treats all packet loss as if they were due to congestion. Consequently, when used in networks that have lossy links, TCP reduces sending rate aggressively when there are transmission (non-congestion) errors in an uncongested network. One solution to the problem is to discriminate between errors; to deal with congestion errors by reducing TCP sending rate and use other actions for transmission errors. In this work we investigate the problem and propose a solution using an end-to-end error discriminator. The error discriminator will improve the current congestion window mechanism in TCP and decide when to cut and how much to cut the congestion window. We have identified three areas where TCP interacts with drops: congestion window update mechanism, retransmission mechanism and timeout mechanism. All of these mechanisms are part of the TCP congestion control mechanism. We propose changes to each of these mechanisms in order to allow TCP to cope with transmission errors. We propose a new TCP congestion window action (CWA) for transmission errors by delaying the window cut decision until TCP receives all duplicate acknowledgments for a given window of data (packets in flight). This will give TCP a clear image about the number of drops from this window. The congestion window size is then reduced only by number of dropped packets. Also, we propose a safety mechanism to prevent this algorithm from causing congestion to the network by using an extra congestion window threshold (tthresh) in order to save the safe area where there are no drops of any kind. The second algorithm is a new retransmission action to deal with multiple drops from the same window. This multiple drops action (MDA) will prevent TCP from falling into consecutive timeout events by resending all dropped packets from the same window. A third algorithm is used to calculate a new back-off policy for TCP retransmission timeout based on the network's available bandwidth. This new retransmission timeout action (RTA) helps relating the length of the timeout event with current network conditions, especially with heavy transmission error rates. The three algorithms have been combined and incorporated into a delay based error discriminator. The improvement of the new algorithm is measured along with the impact on the network in terms of congestion drop rate, end-to-end delay, average queue size and fairness of sharing the bottleneck bandwidth. The results show that the proposed error discriminator along with the new actions toward transmission errors has increased the performance of TCP. At the same time it has reduced the load on the network compared to existing error discriminators. Also, the proposed error discriminator has managed to deliver excellent fairness values for sharing the bottleneck bandwidth. Finally improvements to the basic error discriminator have been proposed by using the multiple drops action (MDA) for both transmission and congestion errors. The results showed improvements in the performance as well as decreases in the congestion loss rates when compared to a similar error discriminator.

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Wang, Yu. "Tip Leakage Flow Downstream a Compressor Cascade with Moving End Wall." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31628.

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A large-scale moving end-wall system has been designed and built at the Aerospace and Ocean Engineering Department of Virginia Tech. This system forms part of a low-speed linear compressor cascade wind tunnel, where it is used to simulate the effects of the relative motion between the blade tips and casing upon the flow. Detailed 4-sensor hot wire measurements were made at various locations downstream the cascade. The results are presented in term of mean flow field and turbulence flow field. In order to reveal the effects of moving end wall, the results also compared with the results obtained with stationary end wall.
Master of Science

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Edwan, Talal A. "Improved algorithms for TCP congestion control." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/7141.

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Reliable and efficient data transfer on the Internet is an important issue. Since late 70's the protocol responsible for that has been the de facto standard TCP, which has proven to be successful through out the years, its self-managed congestion control algorithms have retained the stability of the Internet for decades. However, the variety of existing new technologies such as high-speed networks (e.g. fibre optics) with high-speed long-delay set-up (e.g. cross-Atlantic links) and wireless technologies have posed lots of challenges to TCP congestion control algorithms. The congestion control research community proposed solutions to most of these challenges. This dissertation adds to the existing work by: firstly tackling the highspeed long-delay problem of TCP, we propose enhancements to one of the existing TCP variants (part of Linux kernel stack). We then propose our own variant: TCP-Gentle. Secondly, tackling the challenge of differentiating the wireless loss from congestive loss in a passive way and we propose a novel loss differentiation algorithm which quantifies the noise in packet inter arrival times and use this information together with the span (ratio of maximum to minimum packet inter arrival times) to adapt the multiplicative decrease factor according to a predefined logical formula. Finally, extending the well-known drift model of TCP to account for wireless loss and some hypothetical cases (e.g. variable multiplicative decrease), we have undertaken stability analysis for the new version of the model.

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Pavlick, Bay. "A fuzzy logic based controller to provide end-to-end congestion control for streaming media applications." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001253.

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Freitag, Karl P. "Two-Axis Force Feedback Deflection Compensation of Miniature Ball End Mills." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-10012004-185454/.

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The primary objective of this research is to improve dimensional tolerances and reduce total manufacturing time of precision milling operations through the implementation of force-feedback machining. Force-feedback machining consists of using real-time cutting force measurement integrated with high bandwidth actuation to provide active error compensation of tool deflection. This research focuses on the development and implementation force-feedback machining using miniature (< 1 mm diameter) ball end mills. Due to the thin geometry of these tools, deflection of the tool during machining results in significant form error of the machined part. A piezoelectric two-axis force feedback actuator was designed and developed to measure and compensate for tool deflection errors of miniature ball end mills. Geometric form error was reduced by 75 % thru the application of force feedback machining.

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Obergfell, Klaus. "A vision-based end-point control for a two-link flexible manipulator." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/17654.

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Hayward, Christine R. "A home away from home? : the transitions of older people within two new zealand retirement villages." Thesis, University of Canterbury. Social and Political Sciences, 2012. http://hdl.handle.net/10092/10358.

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This study explores the experiences of retirement village residents as they move from an independent to a supported living environment within a retirement village. It focuses on residents’ perceptions of their transitions and adopts a qualitative approach to understand the nature of their transitions and the way in which they are experienced. A grounded theory framework is used in order to capture the meanings that participants apply to concepts such as home, and to the physical, social, personal and veiled spaces in which they live. The findings from the study reveal that as residents’ health fails, the impact of increasing dependence is such that their sense of social and personal autonomy is gradually eroded. The research also provides insights into residents’ expectations and fears surrounding end of life. In many ways the experiences of the residents in supported living environments do not differ greatly from those of residents in any aged care facility. One major finding of this research, however, is the debilitating impact on well-being that occurs as a consequence of these transitions from independent to supported living, taking place within one physical location – the retirement village – a physical space which promises prospective residents the opportunity for active and positive ageing.

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Kyroglou, George. "“The Importance of Income Inequality at the Top End of the Distribution as Opposed to the Bottom End as Determinant of Growth”." Thesis, Uppsala universitet, Statsvetenskapliga institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-314860.

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The aim of this study was to analyze whether income inequality is a determinant of national growth and whether this influence is different when income inequality in the upper and the lower decile of income distribution are separately examined. According to the statistical analysis that was held, income inequality was found to have some statistically significant connection with the national economic growth of selected OECD countries, but only in the long run. Moreover, the research findings indicate that when a distinction is made between top-end and bottom-end income inequality, top-end inequality has a positive effect on growth, while bottom-end inequality has a negative effect. Investment and fertility rate were not found to have a statistically significant effect on growth. The above findings were evident in all four periods that were studied. The results imply that states in OECD countries, as well as countries not belonging to this group, need to pay heavy attention to bottom-end income inequality, as a means of controlling and fostering their growth potential, while at the same time leaving top-end inequalities, which not only do not undermine growth, but also drive it. Future researchers are encouraged to conduct the same research with other countries as well, especially developing ones, while also including in the research other factors moderating the effects of income inequality in growth.

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Paliouras, Miltiadis. "ANTIMEROS and MILE END, two Bicaudal-C interacting proteins, are required for Drosophila development." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85634.

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Early Drosophila development is a coordinated series of temporal and spatial events leading to specific localized gene expression. The maternally expressed gene Bicaudal-C (Bic-C) encodes a KH-domain RNA binding protein required in the developing oocyte for anterior-posterior patterning and follicle cell migration. The dominant heterozygous phenotype results in the development of embryos with bicaudal and head defects. A two-hybrid screen using BIC-C as "bait" identified the novel protein ANTIMEROS (ATMS) and the SH3-domain containing protein MILE END (MILE).
ATMS is highly conserved between humans and mice, its expression is almost entirely female-specific, and is limited to certain developmental stages. Mutant alleles for atms are able to dominantly enhance the phenotype of Bic-C heterozygotes confirming the Bic-C-atms interaction. Here I show that NOS mislocalization causes the trans-heterozygous phenotype, as introduction of a nos mutation strongly suppresses the bicaudal phenotype. nos transcripts show a hyper-polyandenylation in atms mutant ovaries, an indicator of translational activation, suggesting that ATMS and BIC-C function as translational repressors of nos through changes in its poly(A) tail length.
MILE, contains two highly conserved SH3 domains at the C-terminus. Experiments involving the analysis of mutant alleles and overexpression mile transgenic lines show that MILE is a negative regulator of both Torso and Egfr RTK signaling. Its not clear what functional role BIC-C may have with RTK signaling, but recent evidence suggests that posterior group gene expression influence terminal pole RTK signaling.

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Basford, Jay. "Ex ante evaluations of data structures for end user queries : theory and two experimental tests /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16346.pdf.

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Parrini, Matteo. "Caratterizzazione sperimentale di sistemi di comunicazione UWB." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.

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Questo elaborato presenta la caratterizzazione sperimentale di un sistema di comunicazione e localizzazione della DecaWave. Il sistema analizzato �è il kit EVK1000, che permette di e�ffettuare stime di distanza tra due nodi e una comunicazione robusta ai disturbi e immune alla propagazione multicammino grazie alla tecnologia UWB.

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22

Salvo, Christopher. "Design and Implementation of a Multiphase Buck Converter for Front End 48V-12V Intermediate Bus Converters." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/101938.

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The trend in isolated DC/DC bus converters is to increase the output power in the same brick form factors that have been used in the past. Traditional intermediate bus converters (IBCs) use silicon power metal oxide semiconductor field effect transistors (MOSFETs), which recently have reached the limit in terms of turn on resistance (RDSON) and switching frequency. In order to make the IBCs smaller, the switching frequency needs to be pushed higher, which will in turn shrink the magnetics, lowering the converter size, but increase the switching related losses, lowering the overall efficiency of the converter. Wide-bandgap semiconductor devices are becoming more popular in commercial products and gallium nitride (GaN) devices are able to push the switching frequency higher without sacrificing efficiency. GaN devices can shrink the size of the converter and provide better efficiency than its silicon counterpart provides. A survey of current IBCs was conducted in order to find a design point for efficiency and power density. A two-stage converter topology was explored, with a multiphase buck converter as the front end, followed by an LLC resonant converter. The multiphase buck converter provides regulation, while the LLC provides isolation. With the buck converter providing regulation, the switching frequency of the entire converter will be constant. A constant switching frequency allows for better electromagnetic interference (EMI) mitigation. This work includes the details to design and implement a hard-switched multiphase buck converter with planar magnetics using GaN devices. The efficiency includes both the buck efficiency and the overall efficiency of the two-stage converter including the LLC. The buck converter operates with 40V - 60V input, nominally 48V, and outputs 36V at 1 kW, which is the input to the LLC regulating 36V – 12V. Both open and closed loop was measured for the buck and the full converter. EMI performance was not measured or addressed in this work.
Master of Science

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Laura, Antonovic. "Radiobiological end-points for the theoretical evaluation of the effectiveness of carbon ions and photons in treating tumours with dynamic hypoxia." Doctoral thesis, Stockholms universitet, Fysikum, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-102731.

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Tumours are characterised by unorganised vasculature, which often results in hypoxic regions. Hypoxia is a common cause for photon radiotherapy (RT) treatment failure, as hypoxic cells require up to 2-3 times higher doses compared to well-oxygenated cells for the same effect in terms of cell kill. The increase in dose that would be required to treat the tumours of cancer patients is limited by the radiation sensitivity of surrounding normal tissues. Using carbon ions instead of photons, the radiation dose can be conformed to the tumour to a much higher degree, resulting in an improved sparing of normal tissues. In addition, carbon ions have a much higher radiobiological effectiveness near the end of their range, which is positioned in the tumour. Also, the radiation modes of action leading to cell death when carbon ions interact with living tissues, are less sensitive to the oxygen status compared with the action modes of photons. The focus of this thesis lies in the development of models for the computation of the cell surviving fraction and tumour control probability (TCP) in hypoxic tumours after photon and carbon ion RT. The impact of fractionation was evaluated with regard to possible spatial changes in oxygenation, both for stereotactic body RT and for carbon ion RT. The feasibility of a method to determine and deliver the optimal photon dose for achieving a high TCP according to spatial variations in radiation sensitivity was evaluated in a treatment planning study. The radiobiological models were finally used for the theoretical quantification of the gain in using carbon ions instead of photons. The results show that there are great possibilities to increase the number of positive outcomes of radiation treatment of tumours if the key influential factors are taken into account, such as level and distribution of hypoxia, radiation quality and choice of fractionation schedule.

At the time of the doctoral defence the following papers were unpublished and had a status as follows; Paper 3: Manuscript; Paper 4: Epubl ahead of print; Paper 5: Manuscript

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Noman, Abdullah M. "Two Essays in Empirical Asset Pricing." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1755.

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The dissertation consists of two essays. The first essay investigates the ability of prior returns, relative to some aggregate market returns, to predict future returns on industry style portfolios. By pooling time series of returns across industries for the period between July 1969 and June 2012, we find that prior returns differential predicts one month ahead returns negatively, even in the presence of a set of popular state variables. The predictability remains significant and negative for up to 5 month ahead returns. The predictability is shown to be robust to alternative specifications, estimation methodology and industry classifications. A possible explanation of this finding is based on time–varying (dynamic) loss aversion among investors. More specifically, when combined with house money effects, prior performance has inverse relationship with degree of loss aversion leading to predictability in the next period returns. The second essay examines the nature of time variation in the risk exposure of country mutual funds to the US market movement and to the benchmark foreign market movement. It uses weekly data on 15 closed end funds and 19 exchange traded funds for the sample period between January, 2001 and December, 2012. Conditional factor models are employed to uncover the time variation in the estimated betas through short horizon regressions. The findings of the paper indicate considerable time variation in risk exposure of country mutual funds to the US market and foreign market risk factors. Additional investigation reveals the following observations. First, the US market betas suffer greater variation over the sample period than the target foreign market betas. Second, the overall fluctuation in betas for the closed end funds is found to be higher than that for the exchange traded funds. Third, emerging market funds experience more oscillation in the risk exposure than their developed market counterparts. It is found that a combination of the US macroeconomic state variables and investors’ sentiment can predict future betas significantly. The findings of the paper have important implication for US investors seeking diversification benefits from country mutual funds.

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Xu, Libo. "GAN-based Automatic Segmentation of Thoracic Aorta from Non-contrast-Enhanced CT Images." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295428.

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The deep learning-based automatic segmentation methods have developed rapidly in recent years to give a promising performance in the medical image segmentation tasks, which provide clinical medicine with an accurate and fast computer-aided diagnosis method. Generative adversarial networks and their extended frameworks have achieved encouraging results on image-to-image translation problems. In this report, the proposed hybrid network combined cycle-consistent adversarial networks, which transformed contrast-enhanced images from computed tomography angiography to the conventional low-contrast CT scans, with the segmentation network and trained them simultaneously in an end-to-end manner. The trained segmentation network was tested on the non-contrast-enhanced CT images. The synthetic process and the segmentation process were also implemented in a two-stage manner. The two-stage process achieved a higher Dice similarity coefficient than the baseline U-Net did on test data, but the proposed hybrid network did not outperform the baseline due to the field of view difference between the two training data sets.

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Demling, Nina. "Verstärkung der Zelladhärenz und Induktion des Zell-"Spreading" - eine neue Funktion von RAGE, einem hoch selektiven Differenzierungsmarker humaner Alveolar-Typ 1-Zellen." [S.l. : s.n.], 2005. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11947683.

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DeFreese, James Michael. "Glass Fiber Reinforced Polymer Bars as the Top Mat Reinforcement for Bridge Decks." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/36289.

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The primary objective of this research was to experimentally investigate material and bond properties of three different types of fiber reinforced polymer (FRP) bars, and determine their effect on the design of a bridge deck using FRP bars as the top mat of reinforcement. The properties evaluated include the tensile strength, modulus of elasticity, bond behavior, and maximum bond stress. The experimental program included 47 tensile tests and 42 beam end bond tests performed with FRP bars. Tensile strength of the bars from the tensile testing ranged from 529 MPa to 859 MPa. The average modulus, taken from all the testing, for each type of bar was found to range from 40 GPa to 43.7 GPa. The maximum bond stress from the beam end bond tests ranged from 9.17 MPa to 25 MPa. From the tests, design values were found in areas where the properties investigated were related. These design values include design tensile strength, design modulus of elasticity, bond coefficient for deflection calculations, bond coefficient for crack width calculations, and development length. The results and conclusions address design concerns of the different types of FRP bars as applied in the top mat of reinforcement of a bridge deck. A secondary objective was to evaluate the disparity in results between direct pullout tests, and beam end bond tests. Results from the experimentally performed beam end bond test were compared to previous literature involving the direct pullout tests. Results from the performed beam end bond tests were higher than all of the literature using direct pullout results. No recommendations were given on the disparity between the two test methods.
Master of Science

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28

Yilmaz, Oguz. "Detailed Fem Analysis Of Two Different Splice Steel Connections." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609895/index.pdf.

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Beam splices are typically located at moment contraflexure points (where M=0). Most design specifications require these splices to develop a strength either to meet design forces or a minimum value set by specifications. The design forces are typically determined through elastic analysis, which does not include flexibility of splice connections. In this research, two types of splice connections, an extended end plate splice connection and a flange and web plate bolted splice connection, were tested and analyzed to investigate the effect of the partial strength splice connections on structural response. The splices were designed to resist 40% and 34% of connecting section capacities using current steel design codes, respectively. It has been observed from the experiments and FEM analysis results that splice connections designed under capacities of connecting steel members can result in changes in design moment diagrams obtained from analyses without splice connection simulation and can also significantly decrease the rigidity of the structure endangering serviceability. The differences in design moment diagrams can go up to 50 % of elastic analysis without connection flexibility. The vertical displacements can increase to 155% of values obtained from elastic analysis with no splice connection simulation. Therefore, connection flexibility becomes very important to define in analysis.

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Dogan, Burak. "Development Of A Two-fingered And A Four-fingered Robotic Gripper." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611863/index.pdf.

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In this thesis study, a two-fingered gripper and a four-fingered multipurpose gripper are developed and manufactured. In addition to development of robotic hands, computer control hardware and software are also developed for computer control of both hands. The two-fingered gripper is designed for a specially defined pick and place operation. Its task is to pick a cylindrical work piece and place it in the appropriate position in a flexible manufacturing cell. Pneumatic actuator is used for power generation and mechanical links are used for power transmission. Fourfingered gripper is designed as a multipurpose gripper. The task is not predefined for this gripper, so, human hand and previous dexterous hands are taken as model during design. It consists of 3 fingers and a thumb. It has 1 degree of freedom for every finger and thumb. Pneumatic actuators are also used for this gripper. Rope and pulley system is used for the power transmission mechanism. Structures of both hands are manufactured from 5083 series aluminum. Gripping force can be controlled by the pressure regulator of the pneumatic system for both hands. Computer software is developed for the control of open and close motion of the fingers. Also, a motion control card is designed and manufactured for control of the pneumatic valves.

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Herzel, Lydia. "Co-transcriptional splicing in two yeasts." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-179274.

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Cellular function and physiology are largely established through regulated gene expression. The first step in gene expression, transcription of the genomic DNA into RNA, is a process that is highly aligned at the levels of initiation, elongation and termination. In eukaryotes, protein-coding genes are exclusively transcribed by RNA polymerase II (Pol II). Upon transcription of the first 15-20 nucleotides (nt), the emerging nascent RNA 5’ end is modified with a 7-methylguanosyl cap. This is one of several RNA modifications and processing steps that take place during transcription, i.e. co-transcriptionally. For example, protein-coding sequences (exons) are often disrupted by non-coding sequences (introns) that are removed by RNA splicing. The two transesterification reactions required for RNA splicing are catalyzed through the action of a large macromolecular machine, the spliceosome. Several non-coding small nuclear RNAs (snRNAs) and proteins form functional spliceosomal subcomplexes, termed snRNPs. Sequentially with intron synthesis different snRNPs recognize sequence elements within introns, first the 5’ splice site (5‘ SS) at the intron start, then the branchpoint and at the end the 3’ splice site (3‘ SS). Multiple conformational changes and concerted assembly steps lead to formation of the active spliceosome, cleavage of the exon-intron junction, intron lariat formation and finally exon-exon ligation with cleavage of the 3’ intron-exon junction. Estimates on pre-mRNA splicing duration range from 15 sec to several minutes or, in terms of distance relative to the 3‘ SS, the earliest detected splicing events were 500 nt downstream of the 3‘ SS. However, the use of indirect assays, model genes and transcription induction/blocking leave the question of when pre-mRNA splicing of endogenous transcripts occurs unanswered. In recent years, global studies concluded that the majority of introns are removed during the course of transcription. In principal, co-transcriptional splicing reduces the need for post-transcriptional processing of the pre-mRNA. This could allow for quicker transcriptional responses to stimuli and optimal coordination between the different steps. In order to gain insight into how pre-mRNA splicing might be functionally linked to transcription, I wanted to determine when co-transcriptional splicing occurs, how transcripts with multiple introns are spliced and if and how the transcription termination process is influenced by pre-mRNA splicing. I chose two yeast species, S. cerevisiae and S. pombe, to study co-transcriptional splicing. Small genomes, short genes and introns, but very different number of intron-containing genes and multi-intron genes in S. pombe, made the combination of both model organisms a promising system to study by next-generation sequencing and to learn about co-transcriptional splicing in a broad context with applicability to other species. I used nascent RNA-Seq to characterize co-transcriptional splicing in S. pombe and developed two strategies to obtain single-molecule information on co-transcriptional splicing of endogenous genes: (1) with paired-end short read sequencing, I obtained the 3’ nascent transcript ends, which reflect the position of Pol II molecules during transcription, and the splicing status of the nascent RNAs. This is detected by sequencing the exon-intron or exon-exon junctions of the transcripts. Thus, this strategy links Pol II position with intron splicing of nascent RNA. The increase in the fraction of spliced transcripts with further distance from the intron end provides valuable information on when co-transcriptional splicing occurs. (2) with Pacific Biosciences sequencing (PacBio) of full-length nascent RNA, it is possible to determine the splicing pattern of transcripts with multiple introns, e.g. sequentially with transcription or also non-sequentially. Part of transcription termination is cleavage of the nascent transcript at the polyA site. The splicing status of cleaved and non-cleaved transcripts can provide insights into links between splicing and transcription termination and can be obtained from PacBio data. I found that co-transcriptional splicing in S. pombe is similarly prevalent to other species and that most introns are removed co-transcriptionally. Co-transcriptional splicing levels are dependent on intron position, adjacent exon length, and GC-content, but not splice site sequence. A high level of co-transcriptional splicing is correlated with high gene expression. In addition, I identified low abundance circular RNAs in intron-containing, as well as intronless genes, which could be side-products of RNA transcription and splicing. The analysis of co-transcriptional splicing patterns of 88 endogenous S. cerevisiae genes showed that the majority of intron splicing occurs within 100 nt downstream of the 3‘ SS. Saturation levels vary, and confirm results of a previous study. The onset of splicing is very close to the transcribing polymerase (within 27 nt) and implies that spliceosome assembly and conformational rearrangements must be completed immediately upon synthesis of the 3‘ SS. For S. pombe genes with multiple introns, most detected transcripts were completely spliced or completely unspliced. A smaller fraction showed partial splicing with the first intron being most often not spliced. Close to the polyA site, most transcripts were spliced, however uncleaved transcripts were often completely unspliced. This suggests a beneficial influence of pre-mRNA splicing for efficient transcript termination. Overall, sequencing of nascent RNA with the two strategies developed in this work offers significant potential for the analysis of co-transcriptional splicing, transcription termination and also RNA polymerase pausing by profiling nascent 3’ ends. I could define the position of pre-mRNA splicing during the process of transcription and provide evidence for fast and efficient co-transcriptional splicing in S. cerevisiae and S. pombe, which is associated with highly expressed genes in both organisms. Differences in S. pombe co-transcriptional splicing could be linked to gene architecture features, like intron position, GC-content and exon length.

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Zakrzewski-Sharma, Karan. "PLANT MIGRATION AT THE END OF THE WEICHSELIAN GLACIATION : Macrofossil evidence of early coniferous trees at two northern Swedish sites." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-160214.

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Studies of vegetation history bring a new incentive to our understanding of plant survival and migration in arctic environments. For decades, environmental research was based on palynological data and these studies created a notion that tree species such as larch (Larix sibirica) and Scots pine (Pinus sylvestris) did not grow in northern Scandinavia at the end of Weichselian glaciation. However, findings of macro- and megafossils of these trees dating back to glacial times has been reported in the Swedish mountain range, questioning this view of a late arrival of these trees in Scandinavia. The apparent contrasting views on the composition of the first plants arriving to Scandinavia create uncertainties about the bioclimatic conditions prevailing at the end of the Weichselian glaciation. To improve our understanding about the first vegetation arriving to Scandinavia I probed the macrofossil composition of two novel sedimentary records from northern Sweden. Twelve sediment cores from material underlying Holocene peat deposits were used as archives of early Holocene plants. In these records, I found: I) larch needles dating back to 4.6 and 4.1 calibrated thousand years (cal. kyr) BP; II) pine macrofossils dating back to 9.5 and 8.7 cal. kyr BP; III) fossils from dwarf shrubs (willow and heather) dating back to 9.9 cal. kyr BP; and IV) a birch fossil dating back to 9.5 cal. kyr BP. Also found in the same depth was fragment of a spruce cone. Based on my findings, I concluded that the landscape behind the retreating Weichselian ice-sheet was surpassingly colonised by pine and larch trees, a forest that has no contemporary analogue in Scandinavia. It seems as if this early forest also contained spruce, which is enigmatic as the main spruce invasion is expected to occur across the region during the next millennia. Finally, there is an instigation for future discussion on how our present knowledge of plant behaviour in changing conditions can help minimise the impacts of ever-expanding climate change.

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Bandyopadhyay, Amrita. "Analysis of the Arabidopsis Polyadenylation Factors PAP1, CstF64 and CstF77 and their characteristic inter-relationship." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/601.

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3’-end modification by polyadenylation is a ubiquitous feature of almost all eukaryotic mRNA species and is catalyzed by a consortium of enzymes, the polyadenylation factors. Poly(A) polymerase (PAP), the enzyme catalyzing the addition of adenosine residues during the polyadenylation stage, exists in four isoforms within Arabidopsis. In silico and yeast two-hybrid studies showed that PAP1 has unique expression and interaction pattern in Arabidopsis, suggesting non-canonical functions of PAP1. Its exclusive interaction with PAP4 has not been reported in other living systems until now and hints at a difference in polyadenylation in plants with respect to mammals and yeast. Cleavage Stimulation Factor (CstF), a heterotrimeric complex of the polyadenylation factors CstF50, CstF64 and CstF77, plays a role largely in cleavage of pre-mRNA. This study highlights some aspects of the Arabidopsis homologs of CstF64 and CstF77, central to various cellular processes other than nuclear polyadenylation. In silico studies showed an elevated expression of CstF64 in the pollen while that of CstF77 remained fairly low. Yeast two-hybrid assays indicated a novel kind of interaction of CstF64 with Fip1(V). It is also speculated from sub-cellular localization techniques by agroinfiltration in tobacco leaves that CstF64 localizes in the cytoplasm and CstF77 in the nucleus, as found for the orthologs of CstF77 in other systems.

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Zhu, Qiyao, Yan Hu, and Wentao Guo. "Mobile learning in higher education : Students’ acceptance of mobile learning in three top Chinese universities." Thesis, Internationella Handelshögskolan, Högskolan i Jönköping, IHH, Informatik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-18645.

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Introduction: Along with the swift spread of 3G and wireless network, wireless technologies are applied in many areas, especially in education. The advent of mobile learning overcomes several limitations and barriers of traditional classroom education. As for higher education in China, mobile learning is in its infancy stage. Understanding end-users’ acceptance of mobile learning is crucial, because new technological advances cannot enhance performance if they are not accepted by end-users. This study focuses on three top Chinese universities and answers the following research questions: How do students perceive mobile devices as a learning tool incorporated in class and what are their attitudes towards mobile learning? What are the motivational factors that affect students’ acceptance of mobile learning? Purpose: The purpose of this study is to test the proposed Technology Acceptance Model (TAM) in explaining students’ acceptance in three top Chinese universities. The goal of this work is to enhance the understanding of user acceptance of incorporating learning into mobile device inside and outside classes. Method: A deductive, theory-testing approach was used in this study. Eleven hypotheses were built based on a literature review and on the proposed TAM model, and were tested using primary data and literature review. Primary data was gathered via semi-structured interviews and questionnaires. The data collected through the questionnaire was analysed by Structural Equation Modeling. Conclusion: Through testing the proposed model, the authors found that students are positive towards mobile learning but they do not have a strong willingness to adopt it. The proposed TAM model can improve the understanding of students’ motivation by suggesting what factors are the most important in enhancing students acceptance of mobile learning.

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Kobayashi, Shunsuke. "Rad18 and Rnf8 facilitate homologous recombination by two distinct mechanisms, promoting Rad51 focus formation and suppressing the toxic effect of nonhomologous end-joining." Kyoto University, 2015. http://hdl.handle.net/2433/199188.

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Baker, Susan. "Extending means-end theory through an investigation of the consumer benefit/price sensitivity relationship in two markets (the UK and Germany)." Thesis, Cranfield University, 1996. http://dspace.lib.cranfield.ac.uk/handle/1826/10723.

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This research study is located in the field of consumer behaviour. It positions means-end theory in the interpretivist philosophical tradition and follows a cognitive approach to understanding purchase motivation. The thesis reports on the collection of empirical data to examine the relationship between consumer benefit and price sensitivity as a way of extending means-end theory. The subjects are purchasers of women's fine. fragrances _and trainers, in the UK and Germany. The literature review covers values research, in which means-end theory is contrasted with the macro approach, and price sensitivity, where the advantages of using the price sensitivity mechanism are discussed. The fieldwork is presented as a three-part process. In the pilot stage, constructs for laddering interviews and basic price sensitivity data were elicited from purchasers of the two product categories across the two markets.. The results of the second stage, in-depth interviews are reported as Ä± hierarchical value maps (produced manually) and price sensitivity charts (produced using' Lotus 1-2-3). Stage three involved a large scale survey carried out in both markets and this is then reported along with the results of the final analysis (produced using SPSS). `,' iii Notwithstanding poor response rates among the German samples, the findings support the first research proposition that there is a relationship between consumer benefit and. price sensitivity. The correlation results reveal that a high level of benefit is associated with low price sensitivity among purchasers of trainers in the UK (with a near zero correlation recorded for the German sample). In the case of perfume, a high level of benefit is shown to be associated. with high price sensitivity. Implications of the findings are discussed with reference to both marketing theory and practice. Finally, the strengths and weaknesses of the research design are reviewed, followed. by' the presentation of 14 items for future research.

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Okajima, Hideaki. "Long-term effects of liver transplantation on bone mineral density in children with end-stage liver disease : a two-year prospective study." Kyoto University, 2003. http://hdl.handle.net/2433/148770.

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Kruse, Colin Peter Singer. "Data-Enabled Approach to Characterize Dynamic Regulatory Pathways in Two Kingdoms." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1573746719306039.

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Ramanathan, Sathish Kumar. "Linear Acoustic Modelling and Testing of Exhaust Mufflers." Thesis, KTH, Aeronautical and Vehicle Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4340.

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Intake and Exhaust system noise makes a huge contribution to the interior and exterior noise of automobiles. There are a number of linear acoustic tools developed by institutions and industries to predict the acoustic properties of intake and exhaust systems. The present project discusses and validates, through measurements, the proper modelling of these systems using BOOST-SID and discusses the ideas to properly convert a geometrical model of an exhaust muffler to an acoustic model. The various elements and their properties are also discussed.

When it comes to Acoustic properties there are several parameters that describe the performance of a muffler, the Transmission Loss (TL) can be useful to check the validity of a mathematical model but when we want to predict the actual acoustic behavior of a component after it is installed in a system and subjected to operating conditions then we have to determine other properties like Attenuation, Insertion loss etc,.

Zero flow and Mean flow (M=0.12) measurements of these properties were carried out for mufflers ranging from simple expansion chambers to complex geometry using two approaches 1) Two Load technique 2) Two Source location technique. For both these cases, the measured transmission losses were compared to those obtained from BOOST-SID models.

The measured acoustic properties compared well with the simulated model for almost all the cases.

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Cavalcanti, Ruben Lundgren. "Efeitos cardiorrespiratórios da insuflação torácica associada à pressão positiva expiratória final na toracoscopia experimental de suínos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/25901.

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As vídeo-cirurgias realizadas na cavidade torácica requerem o colapso total ou parcial do pulmão ipsilateral, geralmente obtido pela ventilação pulmonar seletiva (VPS). Uma alternativa à VPS é a ventilação pulmonar não-seletiva (VPNS) em combinação com insuflação torácica (IT) com dióxido de carbono (CO2) no hemitórax do pulmão ipsilateral, o que acarreta alterações cardiorrespiratórias significativas. Para manutenção da homeostasia respiratória nestes pacientes, pode-se utilizar a pressão positiva expiratória final (PEEP), a fim de aumentar a PaO2. Este estudo avaliou, pela primeira vez, os efeitos cardiorrespiratórios de diferentes níveis de IT com CO2 (0, 5 e 10 mm Hg) associado a diferentes níveis de PEEP (5 e 10 cm H2O) em 12 suínos sob anestesia com isoflurano (1 x concentração alveolar mínima) e ventilação convencional durante toracoscopia direita. Um cateter de Swan-Ganz e um analisador de gases foram utilizados para monitorar os parâmetros cardiorrespiratórios durante o experimento. Os dados basais foram obtidos sob VM, sem uso de IT com CO2 e PEEP. Cada animal foi anestesiado uma única vez, recebendo três tratamentos e servindo como seu próprio controle. A indução anestésica foi realizada com bolus de propofol, pela via intravenosa (5 mg/kg). Subseqüentemente à intubação orotraqueal, os animais foram posicionados em decúbito dorsal, conectados ao circuito anestésico reinalatório e instrumentados para registro dos parâmetros das variáveis estudadas. Após a estabilização do plano anestésico, administrou-se pancurônio (0,1 mg/kg, IV) com imediato início da ventilação controlada à pressão com uma FiO2 de 1, objetivando-se a manutenção do valor de ETCO2 entre 35 e 45 mm Hg. As medidas foram divididas em seis momentos (M), com incrementos graduais da pressão de IT: M1 (PEEP de 5 cm H2O e IT de 0 mm Hg); M2 (PEEP 10 e IT 0); M3 (PEEP 5 e IT 5); M4 (PEEP 10 e IT 5); M5 (PEEP 5 e IT 10) e M6 (PEEP 10 e IT 10). Os animais foram ainda divididos em 2 grupos (n=6), onde um recebeu tratamento para manutenção da pressão arterial média (PAM) ≥ 60 mm Hg (grupo não-tratado, GNT; grupo tratado, GTH). Os valores foram submetidos à análise de variância para medidas repetidas para avaliar os efeitos do tratamento nas variáveis hemodinâmicas e pulmonares (p < 0,05). O uso de IT de 10 mm Hg, independente do valor da PEEP associada, induziu uma redução significativa do índice cardíaco, do volume sistólico, do índice de trabalho do ventrículo direito, da complacência dinâmica, do pH arterial e da diferença arteriovenosa de oxigênio, além de aumento na freqüência cardíaca. O uso de PIT de 10 mm Hg, independente do valor da PEEP associada e o uso de PIT de 5 mm Hg associada à PEEP de 5 cm H2O induziu um aumento significativo da diferença alvéolo-arterial de oxigênio, além de redução do conteúdo arterial de oxigênio e da pressão parcial de oxigênio arterial. Ocorreu ainda aumento progressivo da pressão de pico inspiratória, do espaço morto fisiológico, da pressão venosa central, da pressão média da artéria pulmonar e da pressão parcial de CO2 arterial, de acordo com o incremento da IT, além de manutenção das pressões arteriais, em ambos os grupos. Com exceção à associação de PEEP de 5 cm H2O e PIT direita com CO2 de 5 mm Hg, a estratégia ventilatória com PEEP de 5 ou 10 cm H2O e PIT direita com CO2 em níveis pressóricos ≤ a 5 mm Hg pode ser uma ferramenta eficaz para futuros estudos em toracoscopia, em suíno submetido à toracoscopia sob ventilação não-seletiva e FiO2 = 1.
Video-assisted thoracoscopy surgery (VATS) requires lung collapse, at least partially. This condition is usually obtained by one-lung ventilation (OLV). An alternative method is associate two-lung ventilation with carbon dioxide (CO2) insufflation in the operated hemithorax, but this is accompanied by an increased risk of hemodynamic and respiratory deterioration. PEEP can be used in this patients for improve arterial oxygenation. The hemodynamic, ventilatory and blood gases effects of different levels of carbon dioxide insufflations (0, 5 and 10 mm Hg) associated with different levels of PEEPs (5 and 10 cm H2O) under two-lung ventilation were evaluated in twelve isoflurane (1 minimum alveolar concentration) anesthetized pigs during right-sided thoracoscopy. An arterial catheter, Swan-Ganz catheter and multianesthetic gas analyser were used to monitor the cardiopulmonary parameters during the experiment. Baseline data were obtained before intrathoracic pressure (IP) and PEEP elevation. Induction of anesthesia was performed using propofol (5 mg/kg) intravenously. After, the pigs were placed in a dorsal recumbent position and were mechanically ventilated with intermittent positive pressure ventilation. The respiratory rate was adjusted to maintain the end-tidal CO2 concentration between 35 and 45 mm Hg. The measurements were divided in six moments (M), with gradual increment of the IP: M1 (5 cm H2O of PEEP and 0 mm Hg of IP); M2 (10 PEEP and 0 IP); M3 (5 PEEP and 5 IP); M4 (10 PEEP and 5 IP); M5 (5 PEEP and 10 IP) and M6 (10 PEEP and 10 IP). The animals were allocated in two different groups (n=6) which one was treated for maintenance of the mean blood pressure (MBP) ≥ 60 mm Hg. The values were compared among the various time points by use of ANOVA for repeated measures (p < 0,05). IP of 10 mm Hg, independently of the associated PEEP, induced a significant decrease in cardiac index, stroke volume, right ventricular stroke work index, dynamic complacency, arterial pH and arteriovenous oxygen difference, in addition to significant increase in heart rate. IP of 10 mm Hg, independently of the associated PEEP and the application of IP of 5 mm Hg associated with PEEP of 5 cm H2O induced a significant increased in alveolar-arterial oxygen difference, whereas decrease the arterial oxygen content and the partial pressure of arterial oxygen. Peak airway pressure, physiologic dead space, central venous pressure, mean pressure pulmonary artery and partial pressure of arterial CO2 decreased significantly, according with increment of the IP, in addition to maintenance of arterial pressures in both groups. The exception of the combined use of 5 PEEP with 10 IP (M3), the ventilatory strategy with 5 or 10 PEEP associated to carbon dioxide insufflation into the right hemithorax with an intrapleural pressure ≤ 5 mm Hg in 1 MAC isoflurane anesthetized pig under two-lung ventilation with FiO2 = 1, can be an useful adjunct for futures studies in thoracoscopy.

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40

Moning, Renate. "Analysis of test beam data of ECPT and two end cap calorimeter modules of UA2' and its comparison with GEANT and GHEISHA simulations /." [S.l.] : [s.n.], 1988. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

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41

Bowers, Romy Joanna. "B.H. Chamberlain, Lafcadio Hearn, and the Aoki-Kimberley treaty of 1894 : assessments of the end of extraterritoriality by two English interpreters of Meiji Japan." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26722.

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Basil Hall Chamberlain and Lafcadio Hearn were two of the best known western interpreters of Meiji Japan. In their correspondence as well as published writings, they commented on the conclusion of the Aoki-Kimberley treaty of 1894 and the subsequent end of the "unequal treaties" and the treaty port system in Japan. Chamberlain, a resident in Tokyo for over two decades, was most concerned with the fate of foreigners in Japan who would be adversely affected by the end of extraterritoriality and the favourable commercial privileges which they had enjoyed since 1858. He was critical of the jingoism of the nationalistic reaction which developed during the course of treaty negotiations. Hearn, in contrast, praised this national or "racial" spirit and credited it with Japan's success at the negotiation table. Partial to ideas of racial difference and conflict, Hearn viewed the new treaty as evidence of the resurgence of an oriental race against the forces of western imperialism.

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42

Bowers, Romy Joanna. "B.H. Chamberlain, Lafcadio Hearn, and the Aoki-Kimberley Treaty of 1894, assessments of the end of extraterritoriality by two English interpreters of Meiji Japan." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29530.pdf.

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43

Warren, Beckett. "Dawn of a New Apocalypse: Engagements with the Apocalyptic Imagination in 2012 and Primitvist Discourse." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1218993516.

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44

Cadin, Eric. "A tale of two theories: An expository look at the development of the Thomist and the New Natural Law theories and the debates between the two groups from the end of the Second Vatican Council through the release of Veritatis Splendor." Thesis, Boston College, 2012. http://hdl.handle.net/2345/bc-ir:104989.

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45

Ho, I.-Van. "The role of tele-ophthalmology as part of a community health service to remote top end Northern Territory communities cost-effectiveness study of diabetic retinopathy screening, monitoring and management /." Connect to full text, 2006. http://hdl.handle.net/2123/5432.

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Thesis (Ph. D.)--University of Sydney, 2006.
Title from title screen (viewed Oct. 7, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Clinical Ophthalmology and Eye Health, Faculty of Medicine. Includes bibliography. Also available in print form.

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46

Moldovan, Max. "Stochastic Modelling of Random Variables with an Application in Financial Risk Management." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15796/.

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The problem of determining whether or not a theoretical model is an accurate representation of an empirically observed phenomenon is one of the most challenging in the empirical scientific investigation. The following study explores the problem of stochastic model validation. Special attention is devoted to the unusual two-peaked shape of the empirically observed distributions of the conditional on realised volatility financial returns. The application of statistical hypothesis testing and simulation techniques leads to the conclusion that the conditional on realised volatility returns are distributed with a specific previously undocumented distribution. The probability density that represents this distribution is derived, characterised and applied for validation of the financial model.

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47

Demling, Nina. "Verstärkung der Zelladhärenz und Induktion des Zell-Spreading - eine neue Funktion von RAGE, einem hoch selektiven Differenzierungsmarker humaner Alveolar-Typ 1-Zellen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1122277701969-84461.

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RAGE (receptor for advanved glycation endproducts) was identified on endothelial cells as binding partner for AGE-modified molecules. The term "Advanced glycation endproducts" involves a number of structurally diverse molecules, which derive from multiple complex rearrangements of reducing sugars with free amino-groups of proteins. They evolve during food production and also in vivo during ageing and to an accelerated degree in diabetes, where AGEs cause receptor-mediated cellular perturbations. Due to the pathological relevance the aim of this thesis was to generate a "biosensor" for AGEs. To this end, the membrane-expressed receptor (flRAGE) as well as soluble RAGE (sRAGE) were expressed in mammalian cells and investigated in numerous binding studies. These did not reveal a specific interaction of AGE-modified ligands with RAGE. In addition, the expression of RAGE on endothelial cells, as described in the literature, could not be followed neither with the help of newly generated monoclonal anti-RAGE antibodies, nor in quantitative "real time" RT-PCR analysis. These results cast doubts on the meaning of RAGE as a proinflammatory receptor in AGE-mediated pathologies and on the adequacy of RAGE for the "biosensor". At the same time the question concerning a physiological role of the receptor arose. RAGE-expression was analysed in different healthy human tissues by "real time" RT-PCR, which revealed an almost selective expression in lung tissue. An important indication for a possible physiological function of RAGE in lung provided the selective localization of RAGE on alveolar epithelial type I cells as demonstrated in frozen lung sections as well as in in vitro cultivated lung cells. RAGE could be identified as a novel, highly specific marker for the thin, expanded AT I cell, which form part of the air-blood-barrier. In the following, RAGE was found to be an interaction partner for collagen IV, a major component of the alveolar basal lamina. Membrane-expressed RAGE did not only strengthened adherence of cells but also induced cell spreading on collagen IV-coated surfaces. This preferential interaction of RAGE with collagen IV could substantially contribute to the functional morphology of AT I cells in vivo, thereby ensuring an effective bidirectional gas-exchange. The results of this thesis expose a novel, so far unnoticed aspect of the biology of RAGE, which presumably contributes to the phenotypic characteristic und function of normal human lung tissue
RAGE (receptor for advanced glycation endproducts) wurde als Interaktionspartner auf Endothelzellen für AGE-modifizierte Moleküle identifiziert. Unter den "Advanced glycation endproducts" werden eine Vielzahl strukturell unterschiedlicher Moleküle zusammengefasst, die durch mehrstufige komplexe Umlagerungen zwischen reduzierenden Zuckern und freien Aminogruppen von Proteinen entstehen. Sie entstehen sowohl bei der Herstellung von Lebensmitteln, als auch in vivo während des Alterns und in erhöhtem Maß bei Diabetes, wobei sie Rezeptor-vermittelt Zellstörungen hervorrufen. In der vorliegenden Arbeit wurde zunächst aufgrund der pathologischen Relevanz eine Strategie zur Konzeption eines "Biosensors" für AGEs verfolgt. Hierfür wurde sowohl der membranständige Rezeptor (flRAGE) als auch löslicher RAGE (sRAGE) in Säugerzellen exprimiert und in zahlreichen Bindungs- und Funktionsanalysen getestet. Hierbei konnte keine spezifische Interaktion der AGE-modifizierten Moleküle mit RAGE nachgewiesen werden. Auch die in der Literatur beschriebene Expression von RAGE auf Endothelzellen konnte mit Hilfe neu generierter monoklonaler Antikörper, sowie in quantitativen "real time" RT-PCR-Analysen nicht nachvollzogen werden. Diese Ergebnisse warfen Zweifel an der grundlegenden Bedeutung von RAGE als proinflammatorischer Rezeptor in AGE-bedingten Krankheiten auf und stellten damit auch dessen Eignung für einen AGE-Biosensor in Frage. Gleichzeitig warf diese Skepsis die Frage nach einer möglichen physiologischen Funktion dieses Rezeptors auf. Eine vergleichende Analyse der RAGE-Expression in verschiedenen gesunden Geweben mittels "real time" RT-PCR ergab eine nahezu selektive Expression in Lungengewebe. Wichtige Anhaltspunkte für die Funktion von RAGE in der Lunge ergaben sich aus der selektiven Lokalisation des Rezeptors auf Alveolarepithelzellen Typ I (AT I) sowohl in Gefrierschnitten der Lunge als auch nach in vitro-Kultur von Lungenzellen. RAGE konnte als neuer, hoch spezifischer Marker für die lang gestreckten AT 1 Zellen, die einen Teil der Blut-Luft-Schranke bilden, definiert werden. In folgenden Funktionsanalysen konnte RAGE als spezifischer Interaktionspartner für Kollagen IV, einer Hauptkomponente der Alveolar-Basalmembran, identifiziert werden. Membranständiger RAGE verstärkte nicht nur die Adhärenz von Zellen an Kollagen IV-beschichtete Oberflächen, er induzierte auch Zell-"Spreading". Dies gab Anlass für die Vermutung, dass die beobachtete präferentielle Interaktion von RAGE mit Kollagen IV maßgeblich zu der funktionellen Morphologie der AT I Zellen in vivo beitragen könnte, die die Voraussetzung für einen effektiven bidirektionalen Gasaustausch darstellt. Durch die Ergebnisse dieser Arbeit wurde ein neuer, bisher unbeachteter Aspekt der Biologie des RAGE aufgedeckt, der vermutlich entscheidend zur phänotypischen Ausprägung und Funktion des normalen humanen Lungengewebes beiträgt

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48

Výborný, Jiří. "Bezdrátové zabezpečovací zařízení." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217658.

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This Master’s thesis deals with design and construction of a wireless security and surveillance system in ZigBee wireless networks (IEEE802.15.4). The design consists of creating a star network topology with intended monitoring of home area via end device boards paired with coordinator board, which provides basic networking functionality. End device is used to send data from a temperature sensor DS1631 and magnetic reed switches to coordinator. ZigBee module ZDM-A1281-A2 made by MeshNetics company embedded on each board contains a micro controller ATMega1281 and a transceiver AT86RF230 working in a 2,4GHz frequency band. System is able to notice of any door or window move actions and too high temperature. The non-fully functional ZigBee stack, which is called an Open MAC software, based on MAC (Media Access Control ) layer and PHY (Physical) layer from MeshNetics, has been used to develop the user software. Open MAC consists of three application samples in C code. One of them was modified by the user for an application of communication between the module and sensors. The same design with module RC2204AT made by Radiocrafts company was tested as well, but it couldn’t be executed. All developed boards have been constructed and tested via Terminal PC program.

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49

Al, Sofyani Sharaf. "Analytical Modeling and Experimental Analysis of Metalworking Fluids in theMilling Process." University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1494853268000644.

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50

Harrington, Zinta, and zintah@bigpond com. "B Cell antigen D8/17 as a marker of susceptibility to rheumatic fever in Australians and The sharp end of the needle: Rheumatic fever prophylaxis and concepts of care for Yolngu patients A thesis in two parts." Flinders University. School of Medicine, 2005. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060219.200649.

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Aboriginal Australians have some of the worldï¿½s highest rates of rheumatic fever. Two approaches to reducing the burden of rheumatic fever are discussed in this thesis. The B cell antigen D8/17 has a strong association with rheumatic heart disease and may be a universal marker of inherited susceptibility to rheumatic fever. Identifying a population at increased risk of rheumatic fever provides an opportunity to focus primary prevention measures. In part one of the thesis I evaluate the accuracy of D8/17 as a marker of past rheumatic fever amongst Australians from the Northern Territory. D8/17 levels were measured and compared in patients with acute rheumatic fever, rheumatic heart disease or past rheumatic fever, first-degree relatives and healthy, unrelated controls. The mean percentage of B cells positive for D8/17 was 83.7%, 38.9%, 20.2% and 11.6% respectively. The difference between the groups was significant (p-value less than 0.0001). A receiver operator curve analysis indicated that 22.1% of B cells positive for D8/17 was the most accurate cut-off to distinguish patients with acute or past rheumatic fever from healthy subjects. These results indicated that the B cell antigen D8/17 is an accurate marker of past rheumatic fever in Aboriginal Australians and could be a helpful addition to the Jones Criteria for strengthening or excluding a diagnosis of acute rheumatic fever. The intermediate levels of D8/17 expression in the relatives of index cases supports the hypothesis that D8/17 is a marker of an inherited susceptibility to rheumatic fever, although prospective trials are required to provide conclusive proof of this hypothesis. Non-compliance with secondary prophylaxis was suspected to be the cause of increasing rates of rheumatic fever in the Top End. In part two of the thesis I discuss the ï¿½problem of complianceï¿½ with respect to Aboriginal patients, and investigate the factors that affected the delivery and uptake of prophylaxis for rheumatic fever in an Aboriginal community. Patients, relatives and health practitioners were interviewed on the topic of the care of patients with rheumatic heart disease. The data were analysed using the principles of grounded theory. The main finding was the desire for more personalised care and support for patients with rheumatic heart disease from the community clinic, rather than simple medical care. These ideas crystallised through two Yolngu terms to describe care: djaka (to physically care for) and gungayun (to encourage). Thus even from the outset there was divergence in the focus of the ï¿½consumerï¿½- holistic care - and that of the health-care professional/ researcher ï¿½ improving the rate of secondary prophylaxis coverage. With regards to service provision, a significant reason for failure to receive secondary prophylaxis was the differing approaches of urban and community health services, patient mobility, and a differing understanding of the responsibilities of patients and health service providers in the different settings. Other factors pertaining to service provision, such as staff motivation, administrative issues and program coordination affected the uptake of secondary prophylaxis to a lesser extent. With regards to treatment uptake, individual patient factors inhibiting uptake of treatment were apparent in some cases, but treatment refusal was rare. Pain was not found to be a deterrent. No simple relationship was found between treatment compliance and biomedical knowledge of the disease. There was no simple relationship between patient passivity and sense of responsibility that guaranteed compliance. This study demonstrated that the failure to achieve good uptake of prophylaxis for rheumatic fever related as much to factors of service provision as patient factors and that providing holistic care within a familiar and supportive framework is important to Yolngu patients. However, there are real difficulties for health services as they are currently structured to meet the expectations of patients and families.

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Dissertations / Theses on the topic 'Enid Twp'

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