• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 59
  • 56
  • 20
  • 18
  • 12
  • 5
  • 5
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 207
  • 46
  • 43
  • 34
  • 19
  • 18
  • 16
  • 15
  • 15
  • 12
  • 12
  • 11
  • 10
  • 10
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Vilka effekter har strategiska flygallianser på flygbolag? : En fallstudie av SAS

Fatahian, Roshanak, Fritze, Jenny January 2006 (has links)
Flygbranschen är en bransch som är mycket känslig för omvärldsfaktorer. De senaste årens konjunkturnedgång, terrorattentat, epidemier, höga oljepriser samt rådande konkurrenstryck har resulterat i stora lönsamhetsproblem för många flygbolag. Ett sätt att bli mer konkurrenskraftig och förbättra sin position på marknaden är att samarbeta i form av en strategisk allians. Idag finns det tre allianser i flygbranschen: Star Alliance, Oneworld och Skyteam. Den första globala alliansen var Star Alliance som bildades 1997. Företag har under många år samarbetat i olika former. Vissa forskare anser att ett företag inte längre kan välja mellan konkurrens eller samarbete, utan att det handlar om att kombinera de båda strategierna. Denna undersökning avser att ta reda på hur en strategisk flygallians påverkar ett flygbolag. För att avgränsa studien valdes SAS och dess samarbete inom Star Alliance som undersökningsobjekt. Studiens syfte är således att genom en fallstudie undersöka hur ett nätverksbolag har påverkats av att ingå i en strategisk flygallians. Två intervjuer har genomförts, en med en person anställd på SAS med tidigare förflutet i Star Alliance och en med en konsult med mångårig erfarenhet av resebranschen. Resultatet visar att alliansamarbetet inneburit en rad fördelar för SAS. Konkurrensen har mildrats, kostnader reducerats, intäkter och utvecklingsmöjligheter ökat. En av nackdelarna med att ingå i en strategisk allians är att beslutsprocesserna förlängs. Något som SAS dock inte upplever som ett problem då medlemskapet i alliansen varit av stor betydelse för dem. De slutsatser vi har dragit av denna undersökning är att de nämnda fördelarna med allianssamarbete kan ha ett högt pris då det kostar att vara medlem. Vi tror dock att det kan vara värt att betala en summa då samarbetet kan vara av betydelse för flygbolagets överlevnad. Då flygbolagen även samarbetar med flygbolag utanför alliansen ifrågasätter vi strategisk allians som den enda samarbetsformen för att uppnå minskad konkurrens, kostnadsreduceringar, ökade intäkter och utvecklingsmöjligheter.
52

An in depth analysis of the Preferential Bidding System for SAS Crew Planning

Kinnunen, Isabelle January 2015 (has links)
Crew planning is a complex optimization problem that usually is divided into two separate parts, pairing and rostering. In the rostering process crewmembers are assigned a personal roster, a schedule, for the next coming time period. In order for the crew to have an influence on their roster, SAS have implemented a Preferential Bidding System (PBS) where the crew has the ability to express their wishes regarding their roster, formulated as bids. Generally there is an outspoken dissatisfaction among the crew about PBS and how it works and therefore the questions were raised of how the system could be more transparent and how the bid fulfillment could be communicated both internally and externally. The performed analysis was made with regard to bidding pattern and bid fulfillment and was both quantitative and qualitative. The quantitative part consisted of a thorough review of historic data (delimited to only four months) and a questionnaire, targeting the whole crew collective, was set up as a complementary qualitative analysis. In this thesis the work and result is presented. The result of the analysis shows that satisfaction felt by the crew cannot be directly compared to bid fulfillment as it is measured today. The major aspects of improving the PBS should include a simplification regarding mainly bid types, but also actions in order to increase the transparency of the system and awareness. The recommendation to SAS is to present statistics to crew for each bid type regarding number of placed bids, number of possible fulfillments and how much that is fulfilled thus visualizing the possibility to get a bid fulfilled. A revised range of bid types have also been recommended along with a few minor changes.
53

Extending the data mining software packages SAS Enterprise Miner and SPSS Clementine to handle fuzzy cluster membership : implementation with examples /

Wedding, Donald K., January 2009 (has links) (PDF)
Thesis (M.S.) -- Central Connecticut State University, 2009. / Thesis advisor: Roger Bilisoly. "... in partial fulfillment of the requirements for the degree of Master of Science in Data Mining." Includes bibliographical references (leaves 119-124). Also available via the World Wide Web.
54

Is Drosophila song amplitude structure a communication signal?

Brüggemeier, Birgit January 2017 (has links)
Drosophila courtship song has been studied for over 60 years and remains an area of active research today. Several studies have investigated the physiological mechanisms for fly song production, but no unifying account exists. We review fly song production and integrate published data to a mathematical model of courtship song production. We hypothesize that muscle dynamics underlie fluctuations in the amplitude of courtship song. Our model suggests that these fluctuations can be measured and we introduce the term 'song amplitude structure' (SAS) for those measurements. We predict that SAS signals muscle power and we validate our prediction in muscle mutants of the Drosophila myosin light chain (Dmlc2) gene. We then investigate whether SAS is a communication signal in Drosophila. We show that the two species D. melanogaster and D. simulans differ in their SAS and that both females and males behaviourally discriminate their species SAS from other SAS. This suggests that SAS is a communication signal in Drosophila. Perception of SAS may be affected by noise and we therefore examine the effect of noise on responses to SAS. We find that female auditory responses are not impaired by noise in SAS, however male auditory responses are impaired by noise in SAS. This suggests that males and females may be processing noise in SAS differently. Future work should investigate whether sexually dimorphic auditory neurons respond differently to noise in SAS. We hope that our work will be helpful for investigating fluctuations in amplitude of fly song. We also wish that researchers can use our work for studying the mechanisms underlying both the production of SAS and the perception of SAS.
55

Flygande kriskommunikation : En retorisk analys av Norwegians och SAS kriskommunikation understrejkförhållanden

Gilbert, Kevin, Klöfver, Jakob January 2017 (has links)
Den 28 februari år 2015 utbryter en strejk på flygbolaget Norwegian. Drygt ett år senare, den 10 juni år 2016, sker samma sak på flygbolaget SAS. Denna studie syftar till att undersöka hur de båda nämnda företagen hanterade respektive strejk kommunikativt. Företagens pressreleaser i samband med respektive strejk analyseras ur ett förtroendeperspektiv i form av det retoriska begreppet ethos, samt ett kriskommunikationsperspektiv i form av teorin imagereparerande strategier. Pressreleaserna har valts ut för att främja studiens syfte och analyseras främst genom tillämpning av närläsning och hermeneutik och därav svarar studien för kvalitativa resultat. Resultatet av studien visar att både Norwegian och SAS misslyckas med sin kriskommunikation. Inget av företagen lyckas etablera något starkt förtroende hos sin publik och väljer illa lämpade strategier för respektive rådande situation.
56

Vybrané výběrové statistické metody v programu SAS / Selected Sampling Methods in SAS Software

Voříšek, Jan January 2009 (has links)
In the present work we study methodology of different kinds of sample surveys and their design in SAS software. Creating of SAS Enterprise Guide Add-In was the fundamental creative part of this work. This Add-In enables to compute important statistics of sample surveys, without need of being familiar with SAS code. Add-In was created in MSFT Visual Studio 2003 in C # language using a tamplate for Add-Ins provided by SAS. This work contains a general description of the creation of an Add-In as well as the description of the created Add-In for handling the sample surveys and its usage.
57

Pravděpodobnostní rozdělení v programu SAS / Probability distributions in SAS

Rosypal, Martin January 2009 (has links)
The aim of this work is to elaborate the metodology of creation of custom add-ins for statistical application SAS Enterprise Guide and create one of these that would enable to simplify the calculation of quantiles, values of probability mass function (probability density function respectively) and cumulative distribution function and further based on user's specifications create an appropriate graph. In connection with content of this add-in, the presented work includes the recherche from background of twenty two probability distributions that are supported by SAS Enterprise Guide. Custom add-in is programmed in Visual Basic.NET language in development environment Visual Studio 2003, its source code and the codes of graphs, used in this work and the module itself, are due to their extent included in the attached CD. Theoretical part containing the recherche mentioned above is assessed in second and third chapter of this work, the methodology of creation of custom add-ins for SAS Enterprise Guide is described in fourth chapter and own add-in is introduced in chapter five.
58

Accurate Hardware RAID Simulator

Weng, Darrin Kalung 01 June 2013 (has links)
Computer data storage is growing at an astonishing rate. With cloud computing and the growth of the Internet enterprise storage has been predicted to grow at rates as high as 300\% per year. To fulfill this need technologies such as Redundant Array of Independent Disks or RAID are being used in industry today. Not only does RAID increase I/O performance but also provides redundancy measures to protect against hardware failure. Even though RAID has existed for some time now and is well understood, proprietary optimizations such as command scheduling and cache strategies that are employed by current RAID controllers are not well known. This thesis presents a model for RAID 5 that incorporates these features and describes the overall function of hardware RAID controllers. Also a python implementation of this model, Accurate Hardware RAID Simulator (AHRS) is presented and validated against a current hardware RAID controller. It is shown that AHRS can reproduce the behavior of a hardware RAID system with an accuracy of 97.92\% on average compared to a LSI hardware RAID controller.
59

A Retrospective Study of the Opioid Epidemic and Fentanyl Related Overdose Fatality Cases in a Florida West Coast Medical Examiner District Population

Powell, Anne Terese 04 April 2019 (has links)
Opioids are scheduled by the propensity for misuse and abuse with a high rate of dependency and risk of fatal overdose. Opioids can be divided into different classes, including, natural, synthetic, and semi-synthetic. Opiates are naturally occurring and come directly from the opium poppy plant; whereas the semi synthetics opioids are chemical modifications of the poppy plant. Synthetic opioids attach to the opioid receptor but contain no part of the poppy plant. The increased variety and frequency in opioid prescriptions contributed to an opioid epidemic in the United States which is still on going. According to the CDC, the opioid epidemic has occurred in three waves. The first wave of the epidemic began in the 1990’s with the increase in opioid prescription pain medication overdoses. The second wave began around 2010 when heroin overdoses became more prevalent. This was followed by a sharp uptick in fentanyl deaths beginning around the year 2013, indicating the start of the third wave. The opioid epidemic has had a huge cost to society, not just due to deaths but also because of lost productivity, medical expenses and judicial system costs (Florence, Zhou, Luo, & Xu, 2016). To best design and implement strategies to combat this issue, an understanding of the population effected is needed. Since many public health policies are implemented at the regional level, knowing the characteristics and demographics of the epidemic at the local level is important. This study evaluates trends in drug related death cases in the Florida District 6 Medical Examiner Office (MEO) from the calendar years 2011 through 2016. Specifically, it focuses on opioids and the role of fentanyl in overdose related mortality. Additional attention is given to fentanyl and fentanyl analog related deaths. Fentanyl analogs present challenges from an analytical toxicology perspective. Fentanyl analogs can be difficult to detect. Two sets of data from each calendar year were obtained from the MEO. This data was collated, standardized and then statistically analyzed. It was determined that there was not a significant difference in month of the year or the day of the week that drug related fatalities occurred. The time of day was statistically significant with more drug related mortalities occurring during the hours of 8:00am and 4:00pm. When assessing mortality rates, Pinellas and Pasco county demonstrated differences. Pasco county has higher overall mortality for opioid related deaths. Pinellas county has almost twice the number of the opioid, fentanyl, related overdose fatalities. Racial demographics, divided into White, Black, and Asian populations, demonstrated that the White population is disproportionally affected by fentanyl drug related mortality. Binary logistic regression showed that fentanyl and heroin tend to co-occur, and that ethanol, hydrocodone, methadone, morphine, and oxycodone do not usually co-occur with fentanyl in drug related fatalities. These data help elucidate trends in the opioid epidemic at a regional level. There are differences between Pinellas and Pasco county; with the former having more fentanyl related drug deaths and the latter having more opioid related drug deaths over the six years analyzed. An interesting result is derived from the binary logistic regression. It is shown here that fentanyl and heroin tend to co-occur together. It is also shown that ethanol, hydrocodone, morphine, oxycodone, and methadone do not co-occur with fentanyl related overdose cases. Notably, methadone has the strongest negative association with fentanyl related overdoses.
60

Computational Simulations of Flow Past a Rotating Arrangement of Three Cylinders Using Hybrid Turbulence Models

Thomas, Nick Leonard January 2020 (has links)
Over the past 25 years, advances in the field of turbulence modeling have been made in an effort to resolve more scales, preserving unsteadiness within a flow. In this research two hybrid models, Scale-Adaptive Simulation (SAS) and Stress-Blended Eddy Simulation (SBES) are implemented in solving the highly unsteady flow over a rotating arrangement of three cylinders. Results are compared to those from wind tunnel experiments carried out at North Dakota State University. Both models show close agreement with first and second order turbulence quantities, and SBES shows much greater flow structure detail due to its ability to resolve smaller scales. The Strouhal number for the flow is found to be a function of the rotational speed of the arrangement with von Karman-like structures resulting from each cylinder's wake over a full rotation. SAS shows a constant computational cost as Re increases while the SBES's computational cost increases relatively linearly.

Page generated in 0.0484 seconds