34 resultados para errors and erasures decoding


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Verkkopalveluiden ylläpitovaiheessa halutaan varmistua, etteivät palveluun tehdyt muutokset aiheuta verkkopalvelussa virhetilanteita ja palvelu toimii moitteetta. Muutoksen hyväksyntätestaus voidaan tehdä regressiotestauksena vertaamalla palvelun tilaa ennen ja jälkeen muutoksen. Sisältöpainotteisessa verkkopalvelussa testaaminen keskittyy loppukäyttäjälle esitetyn sivun semanttiseen sekä visuaaliseen oikeellisuuteen sekä erilaisiin toiminnallisiin testeihin. Työssä tarkastellaan etenkin suositulla WordPress-julkaisujärjestelmällä toteutettujen verkkopalveluiden ylläpitoa. Keskeisenä osana julkaisujärjestelmillä toteutettujen verkkopalveluiden ylläpitoa on julkaisujärjestelmän ja sitä täydentävien lisäosien päivittämistä ajantasaisiin versioihin. Nämä päivitykset paitsi tuovat uusia ominaisuuksia verkkopalvelun kehittäjille, myös paikkaavat järjestelmän tietoturvahaavoittuvuuksia sekä korjaavat aiemmissa versioissa esiintyneitä virheitä. Tässä työssä kehitettiin kohdeyrityksen aiempia verkkopalveluiden ylläpitoprosesseja niissä tunnistettujen kehityskohteiden perusteella. Uudistettu kokonaisuus jakautuu kahteen kokonaisuuteen: päivitystarpeen seurantaan sekä päivitysten tekemiseen. Päivitystarpeen seurantaa varten kehitettiin uusi työkalu helpottamaan kokonaiskuvan hahmottamista. Päivitysten tekemisen osalta työssä keskityttiin automatisoidun regressiotestauksen kehittämiseen, missä tärkeimpänä testauskeinona käytetään verkkopalvelusta tallennettujen kuvankaappausten vertailuun perustuvaa visuaalista testausta. Uusien ylläpitoprosesseille määriteltiin myös seurannan kohteet uudistuksen onnistumisen ja jatkokehityksen arviointia varten.

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The purpose of this bachelor's thesis was to chart scientific research articles to present contributing factors to medication errors done by nurses in a hospital setting, and introduce methods to prevent medication errors. Additionally, international and Finnish research was combined and findings were reflected in relation to the Finnish health care system. Literature review was conducted out of 23 scientific articles. Data was searched systematically from CINAHL, MEDIC and MEDLINE databases, and also manually. Literature was analysed and the findings combined using inductive content analysis. Findings revealed that both organisational and individual factors contributed to medication errors. High workload, communication breakdowns, unsuitable working environment, distractions and interruptions, and similar medication products were identified as organisational factors. Individual factors included nurses' inability to follow protocol, inadequate knowledge of medications and personal qualities of the nurse. Developing and improving the physical environment, error reporting, and medication management protocols were emphasised as methods to prevent medication errors. Investing to the staff's competence and well-being was also identified as a prevention method. The number of Finnish articles was small, and therefore the applicability of the findings to Finland is difficult to assess. However, the findings seem to fit to the Finnish health care system relatively well. Further research is needed to identify those factors that contribute to medication errors in Finland. This is a necessity for the development of methods to prevent medication errors that fit in to the Finnish health care system.

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In wireless communications the transmitted signals may be affected by noise. The receiver must decode the received message, which can be mathematically modelled as a search for the closest lattice point to a given vector. This problem is known to be NP-hard in general, but for communications applications there exist algorithms that, for a certain range of system parameters, offer polynomial expected complexity. The purpose of the thesis is to study the sphere decoding algorithm introduced in the article On Maximum-Likelihood Detection and the Search for the Closest Lattice Point, which was published by M.O. Damen, H. El Gamal and G. Caire in 2003. We concentrate especially on its computational complexity when used in space–time coding. Computer simulations are used to study how different system parameters affect the computational complexity of the algorithm. The aim is to find ways to improve the algorithm from the complexity point of view. The main contribution of the thesis is the construction of two new modifications to the sphere decoding algorithm, which are shown to perform faster than the original algorithm within a range of system parameters.

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Broadcasting systems are networks where the transmission is received by several terminals. Generally broadcast receivers are passive devices in the network, meaning that they do not interact with the transmitter. Providing a certain Quality of Service (QoS) for the receivers in heterogeneous reception environment with no feedback is not an easy task. Forward error control coding can be used for protection against transmission errors to enhance the QoS for broadcast services. For good performance in terrestrial wireless networks, diversity should be utilized. The diversity is utilized by application of interleaving together with the forward error correction codes. In this dissertation the design and analysis of forward error control and control signalling for providing QoS in wireless broadcasting systems are studied. Control signaling is used in broadcasting networks to give the receiver necessary information on how to connect to the network itself and how to receive the services that are being transmitted. Usually control signalling is considered to be transmitted through a dedicated path in the systems. Therefore, the relationship of the signaling and service data paths should be considered early in the design phase. Modeling and simulations are used in the case studies of this dissertation to study this relationship. This dissertation begins with a survey on the broadcasting environment and mechanisms for providing QoS therein. Then case studies present analysis and design of such mechanisms in real systems. The mechanisms for providing QoS considering signaling and service data paths and their relationship at the DVB-H link layer are analyzed as the first case study. In particular the performance of different service data decoding mechanisms and optimal signaling transmission parameter selection are presented. The second case study investigates the design of signaling and service data paths for the more modern DVB-T2 physical layer. Furthermore, by comparing the performances of the signaling and service data paths by simulations, configuration guidelines for the DVB-T2 physical layer signaling are given. The presented guidelines can prove useful when configuring DVB-T2 transmission networks. Finally, recommendations for the design of data and signalling paths are given based on findings from the case studies. The requirements for the signaling design should be derived from the requirements for the main services. Generally, these requirements for signaling should be more demanding as the signaling is the enabler for service reception.