When data streams transmitted on the networks include wire and wireless parts, the utilizations of bandwidth are usually not good on existing TCP protocol, that is because TCP is not designed for the wireless transferring at first. The SNOOP protocol suggests to cache the data streams from fixed stations to mobile hosts. And do local retransmissions when the data lost is still available on base stations. Our thesis supposes to modify the existing SNOOP protocol, then proving that it reduces many unnecessary timeout on the simulation result. Generating a loss notification back to the TCP sender when there is a packet loss on the wireless link. This notification makes TCP wait a short period of time while base stations is doing local retransmission. These series of mechanisms also avoid low transmit rate which occur when unnecessary timeouts. Besides we preserve the original advantages of SNOOP.

<p>An active database management system can react to predefined events in the database, resulting in performing some appropriate action. ECA-rules are used to capture these predefined events and to express the appropriate action in the active database management system. An event is said to be an atomic occurrence and is either primitive or composite. D-SNOOP and O-SNOOP are two ways to describe the semantics of composite events. D-SNOOP is detection-based (an event is considered to be instantaneous) and O-SNOOP occurrence-based (an event is considered to occur over a time interval). Some problems concerning the detection of composite events using D-SNOOP semantics have been highlighted by Galton and Augusto (2001), who have created the O-SNOOP semantics to rectify some of the shortcomings of D-SNOOP. It is, however, not known what practical consequences O-SNOOP has on applications. To find some of these practical consequences, an advanced application that uses composite events must be used. In this work, the advanced application is a cooperative information system.</p><p>A cooperative information system is a system in which several agents work together to solve some common problem. The agents can take on a role as either manager (service requester) or agent (problem solver).</p><p>In this dissertation an investigation of the differences between O-SNOOP and D-SNOOP in applications handling cooperation protocols is presented. Our first objective has been to model a cooperation protocol using in turn the D-SNOOP and the O-SNOOP semantics. A further objective has been to compare the models of the cooperation protocols to identify any differences between using D-SNOOP and O-SNOOP semantics in applications handling cooperation protocols.</p>

An active database management system can react to predefined events in the database, resulting in performing some appropriate action. ECA-rules are used to capture these predefined events and to express the appropriate action in the active database management system. An event is said to be an atomic occurrence and is either primitive or composite. D-SNOOP and O-SNOOP are two ways to describe the semantics of composite events. D-SNOOP is detection-based (an event is considered to be instantaneous) and O-SNOOP occurrence-based (an event is considered to occur over a time interval). Some problems concerning the detection of composite events using D-SNOOP semantics have been highlighted by Galton and Augusto (2001), who have created the O-SNOOP semantics to rectify some of the shortcomings of D-SNOOP. It is, however, not known what practical consequences O-SNOOP has on applications. To find some of these practical consequences, an advanced application that uses composite events must be used. In this work, the advanced application is a cooperative information system. A cooperative information system is a system in which several agents work together to solve some common problem. The agents can take on a role as either manager (service requester) or agent (problem solver). In this dissertation an investigation of the differences between O-SNOOP and D-SNOOP in applications handling cooperation protocols is presented. Our first objective has been to model a cooperation protocol using in turn the D-SNOOP and the O-SNOOP semantics. A further objective has been to compare the models of the cooperation protocols to identify any differences between using D-SNOOP and O-SNOOP semantics in applications handling cooperation protocols.

Abstract The throughput of a TCP connection is decided by the size of the congestion window. And cwnd increases when an acknowledgement arrives. It leads to that TCP has a bias against connections with long round-trip-time. For enhancing the fairness of TCP, we proposed a new scheme FTCP (Fair TCP). Unlike TCP, in FTCP congestion avoidance state, it compares its RTT with the standard RTT to adjust the increase amount of cwnd when an ACK arrives TCP sender. Therefore FTCP can keep the throughput increase rate of connections with different RTTs be the same. When FTCP enters timeout state, it sets appropriate slow start threshold by calculating the difference value of cwnd / 2 and the cwnd while standard connection achieves ssthresh. So that FTCP can eliminate the difference of throughput between connections with different RTT while leaving the slow start state. FTCP significantly improves the unfair bandwidth distribution between connections with different RTT. TCP connections over wireless links perform badly because of the unnecessary congestion control, inefficiency to burst packet loss, and long delay to slow down the cwnd recovery time. In proposed schemes, Snoop takes BS as a pivot point to cache the unacknowledged TCP packets. When errors occur in wireless link, Snoop retransmits the packets locally from BS instead of retransmitting these packets from sender. And Snoop shields off the duplicate ACKs caused by wireless errors to avoid sender triggering unnecessary congestion control. But Snoop adopts same retransmission style as TCP. It only retransmits one packet per continuous duplicate ACKs. Snoop recovers error packets more quickly and tolerates higher BER than TCP. But Snoop doesn¡¦t really solve the degraded performance problem of multiple errors of TCP. When the channel is the in a very bad quality, Snoop still performs badly. We proposed a new scheme, Csnoop (continuous snoop), extended from Snoop. When bursty errors happen in the wireless links, Csnoop retransmits one lost packets from the BS in first RTT and counts the number of ACKs that arrives BS to calculate the number of lost packets. And Csnoop retransmits these lost packets continuously. When local timeout happens, Csnoop infers that all packets were dropped and retransmits all packets cached in the buffer. Simulations show that Csnoop achieves better throughput compared to Snoop and TCP, especially for bad quality wireless links. Furthermore, Csnoop needs less buffer size to cache the unacknowledged packets at the base station than Snoop.

The implementation of multiple processors on a single chip has been made possible with advancements in process technology. The benefits of having multiple cores on a single chip bring with it a new set of constraints for maintaining fast and consistent memory accesses. Cache coherence protocols are needed to maintain the consistency of shared memory on individual caches. Current cache coherency protocols are either snoop based, which is not scalable but provides fast access for small number of cores, or directory based, which involves a directory that acts as the ordering point providing scalability with relatively slower access. Our focus is on improving the memory access time of the scalable directory protocol. We have observed that most memory requests follow a pattern where in one of the processors, which we will dub the Producer, repeatedly writes to a particular memory location. A subset of the remaining cores, which we will dub the Consumers, repeatedly read the data from that same memory location. In our implementation we utilize this relationship to provide direct cache to cache transfers and minimize the access time by avoiding the indirection through the directory. We move the directory temporarily to the Producer node so that the consumer can directly request the producer for the cache line. Our technique improves the memory access time by 13 percent and reduces network traffic by 30 percent over standard directory coherence protocol with very little area overhead.

Innovations in the microarchitecture and prominent advances in the semiconductor process technology enable sophisticated and powerful microprocessors. However, they also lead to increased power consumption. The main contribution of the thesis is the demonstration of Semantics-Oriented Low Power Architecture techniques that use the semantics of memory references and variables used in an application program to reduce the power consumption in the memory sub-system of a microprocessor. The Semantic-Aware Multilateral Partitioning (SAM) technique reduces the cache and TLB power consumption by decoupling the data TLB lookups and the data cache accesses, based on the semantic regions defined by the programming languages and the software convention, into discrete reference sub-streams, namely, stack, global static, and heap. To reduce the power consumed by the snoops in Chip Multiprocessor, we propose a hardware technique called Selective Snoop Probe (SSP) and a compiler-based hardware supported technique called Essential Snoop Probe (ESP) that use the properties of the program variables. By selectively sending the snoop probes, the SSP and ESP techniques relax the conservative nature of the cache coherency protocol and its implementation to reduce power and improve performance.

This dissertation addresses the way a linguistic grammar can yield to poetic organization in a poetic text. To this end, two corpora are studied: the sung lyrics of country music singer Hank Williams, Sr. and the rapped lyrics of gansgta rap artist Snoop Dogg. Following a review of relevant literature, an account of the poetic grammar for each corpus is provided, including the manifestation of musical meter and grouping in the linguistic text, the reflection of metrical grouping in systematic rhyme, and rhyme fellow correspondence. In the Williams corpus, final cadences pattern much as in the English folk verse studied in Hayes and MacEachern (1998), but differ in that there are more, and therefore more degrees of saliency. Rhyme patterns reflect grouping structure and correlate to patterns in final cadences, and imperfect rhyme is limited to phonologically similar codas. In the Snoop Dogg corpus syllables do not always align with the metrical grid, metrical mapping and rhyme patterning often challenge grouping structure, and imperfect rhyme is more diverse, as has been shown to be the case for contemporary rap generally (Krims 2000, Katz 2008). Following Rice (1997), Golston (1998), Reindl and Franks (2001), Michael (2003), and Fitzgerald (2003, 2007), meter, grouping and rhyme are modeled as driving phonological, morphological and syntactic deviation in Optimality Theoretic terms. In the Hank Williams corpus, metrical mapping and grouping constraints are shown to drive a number of linguistically deviatory phenomena including stress shift, syllabic variation and allomorphy, while rhyme patterning constraints govern syntactic inversion. In the Snoop Dogg corpus, rhyme fellow correspondence and rhyme patterning constraints play a more significant role, driving enjambment, syllabic variation, and allomorphy. Some linguistically deviatory phenomena derive from ordinary language variation, e.g. (flawr)~(flaw.[schwa]r), and some do not, e.g. syllable insertion in insista. The latter is more common in the Snoop Dogg corpus. / text

Denna uppsats tar en blick på hur smak och klass speglas i vår samtida medievärld som präglas av populärkulturella referenser. Genom en kvalitativ semiotisk analys har Klarnas reklamfilm Get Smoooth (2019) analyserats utifrån Roland Barthes semiotiska teorier om hur mening tillskrivs genom visuella koder, i samband med Pierre Bourdieus teorier om hur klass och smak reflekteras genom visuella medel. Här riktar även undersökningen fokus på hur färgen rosa kan besitta delade meningar, beroende på frågor kring genus och sexualitet. Klarnas reklamfilm använder den amerikanska rapartisten Snoop Dogg som frontfigur i en fiktiv, luxuös rosaklädd värld som ska representera deras ekonomiska kredittjänster. Med hjälp av den utvalda teorin och relaterad forskning så studeras det valda materialet för att belysa en större förståelse för hur smak och klasstillhörighet blir representerat genom media och dess effekter. Undersökningen visar på flera semiotiska tecken för två klasstillhörigheter: låg och högklass. Här var Bourdieus teorier ett stöd i avkodningen av dessa tecken och hur kampanjen kan kopplas till ett kulturellt kapital och uttrycka av smak som kopplas till det två olika klasstillhörigheterna. Resultatet av undersökningen är att Klarnas reklamfilm kan ses som ett som ett bevis på det Baumann menar med att våra preferenser om smak inom samhällets fält är i konstant förändring. Slutligen förs det en diskussion om hur rosa har central påverkan i hur smak uttrycken kopplas till det populärkulturella samhället vilket kopplas till senare kritik till Bourdieu.