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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

A systems engineering approach for the deployment of an atmospheric monitoring station / Andrew Derick Venter

Venter, Andrew Derick January 2015 (has links)
Atmospheric monitoring is a vital part of environmental management. Monitoring temporal changes in atmospheric pollution on a local, regional and global scale is important in order to mitigate adverse effects on health and the environment. Currently there is general agreement that atmospheric pollution should be monitored, however, less emphasis is often placed on what should be achieved and the specific monitoring that should be included. Atmospheric pollution monitoring is often hampered by geographically restricted and site specific effects resulting in inefficient or ineffective information transfer to the local manager. The scientific community in the developed world often underestimate problems associated with the maintenance of comprehensive atmospheric measurement stations in Africa. A holistic approach is needed to optimise atmospheric monitoring according to specifications set out by system design; this includes site selection, site design, maintenance and quality control. The aim of this dissertation is to apply the Systems Engineering approach to a case study, the Welgegund atmospheric measurement station (WAMS), to offer a holistic view of interaction between different operational systems and the complexity behind their management in order to be informative to students and personnel from a non-engineering background. A knowledge gap exists that links practical industry related sciences such as engineering to more fundamental and theoretical sciences. In this dissertation the customer need was determined and an operational concept was developed for the WAMS system. The high level goals of the WAMS were derived and stated as applicable to other new as well as established measurement stations. Technical and fundamental requirements such as trained staff for appropriate logistical support and a broad spatial coverage of air quality monitoring were identified. The system boundaries and operational constraints were established for the WAMS, exposing weaknesses and proposing solutions to ensure long term sustainability. Weaknesses include irregular funding periods and retention of expertise (trained students leave academia for industry) whereas a possible solution included overlapping projects and contracts. Functional analysis highlighted the design and establishment process of the WAMS. Physical architectures and interfaces were explored and finally the success of the establishment of the WAMS was evaluated by a reliability block diagram. The reliability of the WAMS system was calculated to be 96.6 %. This agrees well with the percentage data coverage calculated for the gaseous (95.9 %), aerosol (93.4 %) and meteorological (94.6 %) systems (15 min averages). The reliability of the national grid to supply power to the WAMS was found to be the main restrictive component. It may be a challenge interacting and coordinating projects with different disciplines, branches or sectors outside of a speciality project. This study has bridged the gap between industry related sciences such as engineering to more fundamental and theoretical sciences. A framework has been provided that highlights the techniques of Systems Engineering and provides an understanding for the need and process of atmospheric monitoring. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2015
342

A critical review of Operations Excellence programs : a petrochemical company as case study / Neeven Govindsamy

Govindsamy, Neeven January 2014 (has links)
Operations improvement methodologies have been adopted by manufacturing companies since the early 20th century. Japanese manufacturers were able to offer products of high quality and efficient production costs through systems such as Lean. Manufacturers in the West soon adopted systems of their own thereafter. Operations Excellence is a generic term used to describe such systems, and can be described as a management system delivering competitiveness through the continuous improvement of operational performance. This study provides a critical review of the implementation of an Operations Excellence program by examining the system adopted by a petrochemical company in South Africa. The review allowed the implementation shortcomings to be identified so that resolutions could be suggested, thus facilitating successful utilisation of the system. An evaluation of Operations Excellence programs utilised globally and at the case study organisation was carried out as part of a literature study. This research included the critical success factors and lessons learnt from the systems employed by others. Experimental field work was carried out to allow the critical evaluation of the implementation in the case study. The experimental method utilised a combination of qualitative and quantitative methods for data collection. The primary research instrument was a questionnaire designed to examine the degree in which critical success factors and Operations Excellence requirements were present in the organisation. The implementation shortcomings were successfully identified through the experimental work undertaken. These shortcomings, together with the review of the available literature on Operations Excellence, allowed for the proposition of recommendations with the objective of successful utilisation of Operations Excellence programs for large enterprises. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2014
343

A systems engineering approach for the deployment of an atmospheric monitoring station / Andrew Derick Venter

Venter, Andrew Derick January 2015 (has links)
Atmospheric monitoring is a vital part of environmental management. Monitoring temporal changes in atmospheric pollution on a local, regional and global scale is important in order to mitigate adverse effects on health and the environment. Currently there is general agreement that atmospheric pollution should be monitored, however, less emphasis is often placed on what should be achieved and the specific monitoring that should be included. Atmospheric pollution monitoring is often hampered by geographically restricted and site specific effects resulting in inefficient or ineffective information transfer to the local manager. The scientific community in the developed world often underestimate problems associated with the maintenance of comprehensive atmospheric measurement stations in Africa. A holistic approach is needed to optimise atmospheric monitoring according to specifications set out by system design; this includes site selection, site design, maintenance and quality control. The aim of this dissertation is to apply the Systems Engineering approach to a case study, the Welgegund atmospheric measurement station (WAMS), to offer a holistic view of interaction between different operational systems and the complexity behind their management in order to be informative to students and personnel from a non-engineering background. A knowledge gap exists that links practical industry related sciences such as engineering to more fundamental and theoretical sciences. In this dissertation the customer need was determined and an operational concept was developed for the WAMS system. The high level goals of the WAMS were derived and stated as applicable to other new as well as established measurement stations. Technical and fundamental requirements such as trained staff for appropriate logistical support and a broad spatial coverage of air quality monitoring were identified. The system boundaries and operational constraints were established for the WAMS, exposing weaknesses and proposing solutions to ensure long term sustainability. Weaknesses include irregular funding periods and retention of expertise (trained students leave academia for industry) whereas a possible solution included overlapping projects and contracts. Functional analysis highlighted the design and establishment process of the WAMS. Physical architectures and interfaces were explored and finally the success of the establishment of the WAMS was evaluated by a reliability block diagram. The reliability of the WAMS system was calculated to be 96.6 %. This agrees well with the percentage data coverage calculated for the gaseous (95.9 %), aerosol (93.4 %) and meteorological (94.6 %) systems (15 min averages). The reliability of the national grid to supply power to the WAMS was found to be the main restrictive component. It may be a challenge interacting and coordinating projects with different disciplines, branches or sectors outside of a speciality project. This study has bridged the gap between industry related sciences such as engineering to more fundamental and theoretical sciences. A framework has been provided that highlights the techniques of Systems Engineering and provides an understanding for the need and process of atmospheric monitoring. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2015
344

A critical review of Operations Excellence programs : a petrochemical company as case study / Neeven Govindsamy

Govindsamy, Neeven January 2014 (has links)
Operations improvement methodologies have been adopted by manufacturing companies since the early 20th century. Japanese manufacturers were able to offer products of high quality and efficient production costs through systems such as Lean. Manufacturers in the West soon adopted systems of their own thereafter. Operations Excellence is a generic term used to describe such systems, and can be described as a management system delivering competitiveness through the continuous improvement of operational performance. This study provides a critical review of the implementation of an Operations Excellence program by examining the system adopted by a petrochemical company in South Africa. The review allowed the implementation shortcomings to be identified so that resolutions could be suggested, thus facilitating successful utilisation of the system. An evaluation of Operations Excellence programs utilised globally and at the case study organisation was carried out as part of a literature study. This research included the critical success factors and lessons learnt from the systems employed by others. Experimental field work was carried out to allow the critical evaluation of the implementation in the case study. The experimental method utilised a combination of qualitative and quantitative methods for data collection. The primary research instrument was a questionnaire designed to examine the degree in which critical success factors and Operations Excellence requirements were present in the organisation. The implementation shortcomings were successfully identified through the experimental work undertaken. These shortcomings, together with the review of the available literature on Operations Excellence, allowed for the proposition of recommendations with the objective of successful utilisation of Operations Excellence programs for large enterprises. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2014
345

Measuring reputational risk in the South African banking sector

Ferreira, Susara January 2015 (has links)
With few previous data and literature based on the South African banking sector, the key aim of this study was to contribute further results concerning the effect of operational loss events on the reputation of South African banks. The main distinction between this study and previous empirical research is that a small sample of South African banks listed on the JSE, between 2000 and 2014 was used. Insurance companies fell outside the scope of the study. The study primarily focused on identifying reputational risk among Regal Treasury Bank, Saambou Bank, African Bank and Standard Bank. The events announced by these banks occurred between 2000 and 2014. The precise date of the announcement of the operational events was also determined. Stock price data were collected for those banks that had unanticipated operational loss announcements (i.e. the event). Microsoft Excel models applied to the reputational loss as the difference between the operational loss announcement and the loss in the stock returns of the selected banks. The results indicated significant negative abnormal returns on the announcement day for three of the four banks. For one of the banks it was assumed that the operational loss was not significant enough to cause reputational risk. The event methodology similar to previous literature, furthermore examined the behaviour of return volatility after specific operational loss events using the sample of banks. The study further aimed at making two contributions. Firstly, to analyse return volatility after operational loss announcements had been made among South African banks, and secondly, to compare the sample of affected banks with un-affected banks to further identify whether these events spilled over into the banking industry and the market. The volatility of these four banks were compared to three un-affected South African banks. The results found that the operational loss events for Regal Treasury Bank and Saambou Bank had no influence on the unaffected banks. However the operational loss events for African Bank and Standard Bank influenced the sample of unaffected banks and the Bank Index, indicating systemic risk.
346

Measuring reputational risk in the South African banking sector

Ferreira, Susara January 2015 (has links)
With few previous data and literature based on the South African banking sector, the key aim of this study was to contribute further results concerning the effect of operational loss events on the reputation of South African banks. The main distinction between this study and previous empirical research is that a small sample of South African banks listed on the JSE, between 2000 and 2014 was used. Insurance companies fell outside the scope of the study. The study primarily focused on identifying reputational risk among Regal Treasury Bank, Saambou Bank, African Bank and Standard Bank. The events announced by these banks occurred between 2000 and 2014. The precise date of the announcement of the operational events was also determined. Stock price data were collected for those banks that had unanticipated operational loss announcements (i.e. the event). Microsoft Excel models applied to the reputational loss as the difference between the operational loss announcement and the loss in the stock returns of the selected banks. The results indicated significant negative abnormal returns on the announcement day for three of the four banks. For one of the banks it was assumed that the operational loss was not significant enough to cause reputational risk. The event methodology similar to previous literature, furthermore examined the behaviour of return volatility after specific operational loss events using the sample of banks. The study further aimed at making two contributions. Firstly, to analyse return volatility after operational loss announcements had been made among South African banks, and secondly, to compare the sample of affected banks with un-affected banks to further identify whether these events spilled over into the banking industry and the market. The volatility of these four banks were compared to three un-affected South African banks. The results found that the operational loss events for Regal Treasury Bank and Saambou Bank had no influence on the unaffected banks. However the operational loss events for African Bank and Standard Bank influenced the sample of unaffected banks and the Bank Index, indicating systemic risk.
347

Energy Saving vs. Performance: Trade-offs in Optical Networks

Wiatr, Pawel January 2016 (has links)
The energy consumption of communication networks is continuously growing. Many energy saving approaches have been proposed at the device, system, and network level. The most promising way to address this problem is to utilize photonic technologies as much as possible thanks to their low energy consumption per bit performance. Moreover, several approaches have been proposed to further reduce the energy consumption in optical networks. One popular technique exploits low power modes (e.g., sleep or doze mode) for devices that are not used. However, sleep mode based approaches may affect the way optical connections (i.e., lightpaths) are routed, or alter the characteristics of some devices. This in turn may have a detrimental impact on crucial network/device performance parameters. In other words a green approach may introduce additional delay, change the level of resource utilization in the network, or even impact the lifetime of a device, resulting in increased network operational cost. This thesis provides a study that carefully assesses, in both access and core networks, the trade-off between the benefits of sleep-based energy-efficient schemes and their possible side-effects. In fiber access networks putting a device into sleep mode and waking it up can introduce a significant energy overhead. Already proposed energy-efficient approaches reduce this overhead by aggregating as much as possible the traffic before a transmission. However, aggregating data may cause an additional delay that in some cases might not be acceptable. This thesis investigates the trade-off between energy saving and additional packet delay in the case of a LTE backhaul network based on wavelength division multiplexing passive optical network (WDM-PON). The thesis proposes a novel energy-efficient approach based on the dozing concept able to precisely control when a transmitter needs to wake up in order to maximize the time spent in sleep mode, while assuring that packet transmissions are completed before a given deadline. The proposed scheme is also able to exploit possibly diverse traffic delay requirements to further improve energy saving performance. In optical core networks, one way to decrease the energy consumption is to minimize the number of used active devices by aggregating the lightpaths on the lowest possible number of active fiber links. Routing strategies based on this intuition are beneficial in terms of energy saving, but on the other hand may impact the network performance (e.g., blocking probability) by affecting length of the lightpaths and link occupancy distribution. This trade-off is evaluated in the thesis with the help of a specially designed routing and wavelength assignment (RWA) strategy referred to as weighted power aware lightpath routing (WPA-LR). The WPA-LR strategy permits the fine tuning between the minimization of two objectives: energy consumption and network resource (i.e., wavelength) utilization. Evaluation results confirm that energy efficiency and network performance are conflicting objectives. However, the proposed WPA-LR strategy offers energy minimization with acceptable impact on the network performance. The thesis also investigates the impact that sleep-based energy-efficient strategies have on the lifetime of a number of optical network devices, in both access and core networks. In fact, utilizing a sleep mode functionality may change the operational conditions of the device which can impact the device lifetime. This is a crucial aspect to consider because it may directly affect the network operational cost related to fault management. The thesis provides a methodology to assess under which conditions and for which devices an energy-efficient scheme may lead to overall cost benefit vs. a (possible) increase of reparation cost. It was found that in access networks and with business customers a small lifetime variation in optical line terminals (OLTs) or in optical network units (ONUs) can lead to significant cost increase that cannot be covered by the profits coming from the energy saving. In core networks erbium doped fiber amplifiers (EDFAs) are the most vulnerable devices in terms of impact on their lifetime. For this reason it was found that the usage of green routing algorithms based on putting EDFAs into sleep mode may not always be economically beneficial. In conclusion this thesis provides a different perspective on sleep mode based energy-efficient algorithms where the potential benefit in terms of energy saving is weighted against the impact of a possible degradation of the network performance and devices lifetime. On the other hand these performance degradations can be controlled and limited by the proposed algorithms. / Energikonsumtionen av kommunikationsnätverk, växer kontinuerligt. Många energibesparande åtgärder har föreslagits, såväl på komponentnivå, systemnivå och nätverksnivå. Det mest lovande sättet att hantera energibehov i kommunikationsnätverk är att utnyttja optisk teknologi så mycket som möjligt då denna har potential att ge låg energiförbrukning per bit. Det finns också ett antal föreslagna metoder för att ytterligare reducera energibehovet i optiska nätverk. En av de mest använda teknikerna bygger på att låta enheter som ej används gå ner på låg effekt (”sovläge”). Om detta används i allt för hög utsträckning kan det dock påverka hur optiska förbindelser (sk lightpaths) sätts upp eller ge förändrade egenskaper hos de aktuella komponenterna. Detta kan i sin tur ha en skadlig inverkan på de centrala nätverks- och komponentegenskaper vilket påverkar prestandan. Med andra ord kan en sådan ”grön” ansats baserad på sovläge leda till ökad fördröjning, förändring av resursutnyttjandet i nätet och till och med påverka risken för att det uppstår fel i komponenterna vilket ökar driftskostnaden för nätet. Denna avhandling fokuserar på dessa aspekter och visar upp resultat som belyser avvägningen mellan sovlägesbaserade energieffektiva strategier och deras eventuella bieffekter. Att slå av och väcka upp komponenter i optiska access-nätverk kan vara förknippat med en signifikant extra energikostnad. Tidigare föreslagna energieffektiva strategier försöker reducera denna ökade energikostnad genom att samla så mycket trafik som möjligt innan överföringen sker. Dock kan detta leda till ökad fördröjning som i vissa lägen inte är acceptabel. I avhandlingen undersöker vi avvägningen mellan energibesparingar och ökad paketfördröjning i fallet med LTE distributionsnät baserade på våglängsmultiplexerade passiva optiska nätverk (WDM-PON). Vi föreslår en ny energieffektiv ansats baserad på att enheter försätts i ”slummer-läge”. Detta gör det möjligt att med god precision bestämma när en sändare behöver väckas upp i syfte att maximera tiden i sovläget och att försäkra sig om att paketen kommer fram inom avsedd tid. Strategin är även kapabel att utnyttja differentierad fördröjning för att ytterligare förbättra energibesparingen. Ett sätt att minska energikonsumtionen i optiska distributionsnät är att minimera antalet aktiva enheter genom att exempelvis samla optiska förbindelser till ett minimalt antal aktiva fiberlänkar. Routingstrategier som utgår från denna princip är fördelaktiga ur energisynpunkt men kan å andra sidan skada nätverksprestanda (exempelvis blockeringssannolikhet) genom påverkan på förbindelselängder och annorlunda belastning av länkarna. Denna avvägning utvärderas i avhandlingen med hjälp av en specifikt utformad strategi för routing och våglängstilldelning (RWA) som vi benämner ”viktad effektmedveten optisk förbindelserouting” (WPA-LR). Denna strategi möjliggör noggrann avvägning mellan minimeringen av två kriterier: å ena sidan energikonsumtion, å andra sidan utnyttjandet av nätverksresurser (speciellt väglängdsutnyttjandet). Vår utvärdering bekräftar att energieffektivitet och nätverksprestanda står i motsatsförhållande till varandra. Dock erbjuder WPA-LR strategin minimering av energin med en acceptabel påverkan på nätverksprestanda. Slutligen undersöks i avhandlingen den påverkan som sovlägesbaserade energieffektiva strategier har på livslängden för optiska nätverkskomponenter, både i access- och i distributionsnät. Användning av sovlägesfunktion kan påverka arbetsförhållandena för en komponent, något som i sin tur kan påverka livslängden. Detta är en kritisk aspekt att ta i beaktande då det direkt kan påverka driftskostnaden kopplad till nätunderhållet. En metod ges för att utvärdera under vilka förhållanden och för vilka enheter en energieffektiv strategi kan leda till en total kostnadsfördel jämfört med en (möjlig) ökning av reparationskostnaderna. Ett resultat är att, i accessnät och för företagsanvändare, så kan även en liten variation i feluppkomst i optiska linjeterminaler (OLTs) eller optiska nätverksenheter (ONUs) leda till signifikanta kostnadsförluster vilka inte kan kompenseras genom de vinster som kan åstadkommas med energibesparingar. I distributionsnät är erbium-dopade fiberförstärkare (EDFAs) de mest utsatta enheterna vad gäller inverkan på livslängd. Genom att studera routingstrategier (ex.vis WPA-LR) har vi funnit att användningen av ”gröna” routingalgoritmer baserade på att lägga EDFAs i sovläge inte alltid är ekonomiskt fördelaktigt. Denna avhandling ger ett perspektiv på sovlägesbaserade energieffektiviseringsalgoritmer där de potentiella fördelarna vad gäller minskade driftskostnader ställs mot möjliga försämringar av nätverksprestanda och komponenters livslängd. Å andra sidan kan dessa försämringar hållas under kontroll och begränsas av den föreslagna algoritmen. / La consommation d'énergie des réseaux de communication ne cesse de croître. Ce problème fait l’objet de nombreuses approches orientées vers les économies d'énergie (écoénergétiques) au niveau des appareils (équipements) des systèmes et des réseaux. La façon la plus prometteuse de limiter l’augmentation de consommation évoquée est d'utiliser autant que possible des technologies photoniques, vu leur faible consommation d'énergie par bit. Plusieurs autres approches ont été proposées pour réduire davantage encore la consommation d'énergie dans des réseaux optiques. Une technique populaire exploite les modes de faible puissance (par exemple le mode veille) pour les appareils qui ne sont pas utilisés. Cependant, les approches basées sur le mode de veille peuvent affecter la manière dont les liaisons optiques (circuits optiques) sont acheminées, ou modifier les caractéristiques de certains appareils. Cela peut avoir un impact négatif sur les paramètres de performance des réseaux/équipements cruciaux. En d'autres termes, une approche écoénergétique peut introduire un retard supplémentaire, changer le niveau d'utilisation des ressources dans le réseau, ou même avoir un impact sur le taux d'échec d'un équipement, entraînant une augmentation des coûts d'exploitation du réseau. Cette thèse évalue attentivement, à la fois dans le réseau d'accès mais aussi dans le cœur du réseau, le compromis entre les avantages des régimes économes en énergie utilisant le mode veille et leurs effets secondaires possibles. Dans les réseaux d'accès optiques, mettre un équipement en mode veille et le réactiver peut introduire une surcharge d'énergie significative. Les approches d'économie d'énergie déjà proposées réduisent cette surcharge en regroupant autant que possible le trafic avant sa transmission. Toutefois, les données d'agrégation peuvent provoquer un retard supplémentaire qui peut ne pas être acceptable dans certains cas. Cette thèse étudie le compromis entre les économies d'énergie et un retard supplémentaire des paquets dans le cas d'un réseau backhaul LTE basé sur réseau optique passif à multiplexage en longueur d'onde (WDM-PON). La thèse propose une nouvelle approche éco énergétique. Elle développe un concept au travers duquel il est possible de contrôler avec précision quand un émetteur doit se réactiver, afin de maximiser le temps passé en mode veille tout en veillant à ce que les transmissions de paquets soient terminées en temps voulu. Le schéma proposé est également capable d’exploiter les (éventuelles) exigences diverses de retard de trafic pour améliorer encore les économies d'énergie. Dans le cœur des réseaux optiques, on peut diminuer la consommation d'énergie en minimisant le nombre d’équipements actifs utilisés pour l’acheminement des circuits optiques et le nombre de liens actifs à fibres optiques. Les stratégies de routage basées sur ce principe sont bénéfiques en termes d'économie d'énergie, mais peuvent affecter les performances du réseau (par exemple, la probabilité de blocage) en affectant la longueur des circuits optiques et la distribution d’occupation des liens. Ce compromis est évalué dans la thèse avec l'aide d’une stratégie de routage et affectation de longueur d'onde (RWA) appelée routage des circuits optiques conscient de la puissance (WPA-LR). La stratégie WPA-LR permet le réglage fin entre deux objectifs: minimiser la consommation d'énergie et minimiser l’utilisation des ressources réseau (i.e. longueur d'onde). Les résultats de l'évaluation confirment que l'efficacité énergétique et les performances du réseau ont des objectifs contradictoires. Cependant, la stratégie WPA-LR proposée permet la minimisation de l'énergie avec un impact acceptable sur les performances du réseau. La thèse étudie également l'impact que les stratégies d’économie d’énergie basées sur le mode veille ont sur la durée de vie d'un certain nombre d’équipements de réseau optique, dans les deux réseaux d'accès et de base. L'utilisation du mode veille peut en effet modifier les conditions de fonctionnement de l’équipement, ce qui peut influer sur la durée de vie de l'appareil. Ceci est un aspect crucial à considérer, car il peut affecter directement le coût opérationnel du réseau lié à la gestion des pannes. La thèse propose une méthodologie pour évaluer dans quelles conditions et pour quels dispositifs un système économe en énergie peut conduire à des avantages de coûts globaux par rapport à une (possible) augmentation des coûts de maintenance. Dans les réseaux d'accès et auprès de clients commerciaux, il a été constaté qu’une petite variation de taux d'échec dans les terminaux de ligne optique (OLT) ou dans les unités de terminaison de réseau optique (ONUs) peut conduire à des pertes financières importantes qui ne peuvent être compensées par les bénéfices provenant des économies d'énergie. Dans les cœurs de réseaux les amplificateurs à fibre dopée en erbium (EDFA) sont les équipements les plus vulnérables en termes d'impact sur leur durée de vie. Pour cette raison, l'utilisation d'algorithmes de routage écoénergétiques basé sur la mise en mode veille des EDFA peut par conséquent n’être pas toujours économiquement avantageuse. En conclusion, cette thèse fournit une perspective différente sur des algorithmes économes en énergie basés sur l’utilisation du mode veille. Leur bénéfice potentiel en termes d'économie d'énergie est comparé à l'impact d'une éventuelle dégradation d’une part de la performance du réseau et d’autre part de la durée de vie des équipements. Ces dégradations de performances peuvent être contrôlées et limitées par les algorithmes proposés. / Zużycie energii elektrycznej w sieciach komunikacyjnych stale rośnie. Do tej pory zostało zaproponowanych wiele metod oszczędzania energii na poziomie urządzeń, systemów i sieci. Najbardziej obiecującym podejściem do tego problemu jest wykorzystanie technologii optycznych, z uwagi na ich niskie zużycie energii „per bit”. Ponadto wiele różnych metod przeznaczonych dla sieci optycznych zostało przedstawionych w literaturze. Jedna z popularnych technik wykorzystuje tryb niskiego poboru energii (uśpienia) w urządzeniach, które nie są używane. Jednakże techniki wykorzystujące tryb uśpienia mogą mieć wpływ na kierowanie optycznych połączeń sieciowych (lightpaths) lub zmieniać właściwości urządzeń. Natomiast to może mieć negatywny wpływ na kluczowe parametry wydajności sieci czy urządzeń sieciowych. Innymi słowy algorytmy oszczędzające energię mogą wprowadzić dodatkowe opóźnienia, zmienić wykorzystanie zasobów sieciowych, a nawet wpływać na awaryjność urządzeń zwiekszając tym samym koszt eksploatacji sieci. Praca ta przedstawia i analizuje kompromis pomiędzy korzyściami płynącymi z energooszczędnych algorytmów opartych na trybie uśpienia, a ich ewentualnymi skutkami ubocznymi, zarówno w sieciach dostępowych, jak i szkieletowych. W przypadku optycznych sieci dostępowych proces wprowadzenia urządzenia w tryb uśpienia i jego wybudzenia może spowodować znaczący narzut energetyczny. Proponowane sposoby zmniejszenia tego narzutu agregują ruch sieciowy przed jego transmisją, Jednakże taka agregacja powoduje dodatkowe opóźnienia transmisji, które w niektórych przypadkach mogą być niedopuszczalne. Praca ta analizuje kompromis pomiędzy oszczędzaniem energii, a dodatkowymi opóźnieniami transmisji w przypadku sieci LTE-backhaul, bazowanej na technologii pasywnych sieci optycznych, opartych na multipleksowaniu z podziałem długości fali WDM-PON (Wavelength Division Multiplexing Passive Optical Network). Niniejsza praca proponuje nowatorską metodę oszczędzania energii, opartą na koncepcji drzemki (dozing), która precyzyjnie kontroluje czas wybudzania nadajnika, tak aby zmaksymalizować czas spędzony w trybie drzemki, przy zapewnieniu, że transmisja danych zostanie zakończona przed upływem wymaganego czasu. Proponowana metoda wykorzystuje również zróżnicowane wymagania maksymalnych opóźnień transmitowanych danych do dalszej poprawy wydajności energetycznej. Jednym ze sposobów zmniejszania zużycia energii w światłowodowych sieciach szkieletowych jest zredukowanie liczby aktywnych urządzeń, poprzez umiejętne kierowanie optycznych połączeń sieciowych przy użyciu już aktywnych łączy światłowodowych. Kierowanie ruchu sieciowego oparte na tym pomyśle jest korzystne z punktu widzenia oszczędzania energii, choć z drugiej strony może mieć wpływ na parametry wydajnościowe sieci (np. zwiększenie prawdopodobieństwa blokady połączeń) poprzez oddziaływanie na długość połączeń, czy zajętość łączy. Przytoczony problem jest analizowany w tej pracy za pomocą specjalnie zaprojektowanego algorytmu routingu i przypisania długości fali RWA (Routing and Wavelength Assignement), nazwanego WPA-LR (Weighted Power Aware Lightpath Routing). Algorytm WPA-LR pozwala na precyzyjną regulację pomiędzy redukcją zużycia energii i optymalizacją wykorzystania zasobów sieciowych. Wyniki wykonanej analizy problemu potwierdzają, że efektywność energetyczna i wydajność sieci to cele ze sobą sprzeczne. Jednakże proponowana strategia (WPA-LR) umożliwia kontrolę i osiągnięcie kompromisu pomiędzy zmniejszeniem zużycia energii, a pogorszeniem wydajności sieci. Praca ta bada również wpływ energooszczędnych strategii, opartych o tryb uśpienia, na trwałość optycznych urządzeń sieciowych, zarówno w sieciach dostępowych, jak i szkieletowych. Używanie trybu uśpienia może zmienić warunki pracy urządzenia, które z kolei mogą mieć wpływ na jego trwałość. Natomiast zmniejszenie trwałości urządzenia może bezpośrednio oddziaływać na koszt eksploatacji sieci związany z zarządzaniem awariami. Niniejsza praca proponuje metodologię oceny, na jakich warunkach i w przypadku których urządzeń, używanie algorytmów oszczędzania energii może prowadzić do ogólnych korzyści finansowych lub strat związanych ze wzrostem kosztu eksploatacji sieci. W pracy stwierdzono, że w sieciach dostępowych, w szczególności obsługujących klientów biznesowych, mały wpływ na awaryjność optycznych terminali ONU (Optical Network Unit) lub optycznych urządzeń dystrybucyjnych OLT (Optical Line Terminal) może prowadzić do znacznego zwiększenia kosztów, które mogą przekroczyć zyski związane z oszczędzaniem energii. W sieciach szkieletowych wzmacniacze światłowodowe EDFA (Erbium Doped Fiber Amplifier) są najbardziej wrażliwymi urządzeniami pod względem wpływu na ich awaryjność. W pracy dowiedziono, że użycie energooszczędnych algorytmów kierowania połączeń światłowodowych, opartych na wprowadzaniu EDFA w tryb uśpienia, nie zawsze jest korzystne ekonomicznie. Niniejsza praca przedstawia nowatorskie spojrzenie na energooszczędne algorytmy oparte na wprowadzaniu urządzeń w tryb uśpienia, gdzie potencjalne korzyści w zakresie oszczędzania energii są porównane ze stratami związanymi z degradacją wydajności sieci lub żywotności urządzeń sieciowych. / <p>QC 20160509</p>
348

The effects of regulations on risk management within the Swedish Banking Sector

Parfenova, Alina, Karlsson, Lena January 2016 (has links)
This research shed the light on regulations and their effects on operational risk management within the Swedish Swedish Banking Sector. The focus lies on operational risk management due to the introduction of new regulations such as FFFS 2014:1, FFFS 2014:4 and FFFS 2014:5. What could be found in the empirical analysis is that the regulations affected organizational changes.  Additionally, differences between large and small banks could be seen. All changes in terms of implementation of regulations are strongly performed throughout the Three Lines of Defence model where clear organization structure and work description are of importance. The Three Lines of Defence is tightly combined with the COSO framework and operational risk management to conduct compliant organization that is adaptable for any regulatory changes.
349

Resilience in the humanitarian sphere : stimulating resilience for recovery in Haiti

King, Katrice G. January 2015 (has links)
Severe recovery deficits after post-disaster interventions have become the landscape seen globally. Humanitarian operations have struggled to find coherence between relief and recovery activities, which has resulted in a perceived operational gap between relief, recovery and development. This current dynamic has caused significant deficiencies within humanitarian programming, such as weak strategy, a lack of transition mechanisms, exit plans and effective recovery. A situation that stems from the current paradigm the humanitarian system operates under and the framework that has evolved around it. Supporting the development of adaptive resilience of a disaster-affected population, within the humanitarian sphere, has been theoretically posed to be fundamental for recovery; a programmatic consideration that could ensure former weak resilience would not hinder post-disaster recovery. Therefore, could a resilience building approach offer much needed solutions to the challenge of recovery within post-disaster contexts? This research aimed to understand whether resilience building within post-disaster environments could increase potential recovery of disaster affected populations and whether it is feasible to build individual/household (HH) level resilience through emergency response operations? The research looked specifically at adaptive resilience at the individual/HH level, clarifying the concept and understanding its modality in order to operationalise it within humanitarian programming. The common barriers to recovery experienced by individuals/HH in a crisis event were gauged, and the relationship between adaptive resilience and recovery determined. A unique singular case study was used to collect quantitative and qualitative data required to answer the key objectives of this research. The case study chosen was the 2010 Haiti earthquake response. Primary data was collected over a 7 months period through 37 semi-structured interviews and 31 online questionnaires with donors, government, INGOs, LNGOs and the private sector, that were operating within the Haiti response, and 18 disaster affected community members within a community discussion forum. Bringing a total participation of 86 individuals and organisations. An in-depth case study was developed in order to offer an evidence base for the proposed theory, that supporting adaptive resilience through emergency response programming has the ability to stimulate recovery. A new data collection tool was trialed within the community discussion forum, namely the Sociogram. This tool looked to assess the main components of adaptive resilience. Methodological rigour was introduced through the use of methodological and data triangulation to ensure validity and reliability of the research. The research successfully identified the main barriers to recovery, pinpointed the key components for adaptive resilience and the influence of emergency programming on the development of adaptive resilience, establishing the relationship between them. The role emergency response operations can play in the development of adaptive resilience was then explored. It has been demonstrated that to ensure recovery and allow for a more resilient society to evolve, adaptive resilience needs to be and can be supported and developed within emergency response operations. The research has been able to demonstrate, through the analysis of the Shelter and WASH response undertaken in Haiti, that developing resilience in the post-disaster environment is possible and an approach that is able to improve strategy within emergency response operations. Improvements would be seen in the provision of essential services within the response, a substantial increase in transitional and exit options and an increased capacity to proactively stimulate rapid recovery. This strategic approach to emergency response programming has the ability to offer the coherence needed between relief, recovery and development. Determining that a resilience building approach within emergency response operations could be the missing link or resolution to the perceived operational gap between relief, recovery and development. Pursuing a resilience building approach has the potential to bring much needed cultural change within the humanitarian sector that will shape operations for a more strategic and successful future.
350

MIGRATION FROM VAX TO MODERN ALPHA COMPUTERS

Nötzel, Klaus R. 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Deutsche Telekom has been operating different communication satellites for several years. The Satellite Control Center (SCC) of Deutsche Telekom is located near Usingen, about 50 km northwest of Frankfurt/Main. The system has been under operation since the launch of the first flight model DFS in June 1989. The entire computer system was based on Digital Equipment Corporation (DEC) VAX type computers. The maintenance costs of these old Complex Instruction Sets Computers (CISC) were increased significantly during the last years. Due to the high operational costs Deutsche Telekom decided to exchange the operational computer system. Present-day information technology world uses more and more powerful Reduced Instruction Set Computers (RISC). These new designs allow operational costs to be reduced appreciably. The VAX type computers will be replaced by DEC Alpha AXP Computers. This paper describes the transition process from CISC to RISC computers in an operational realtime environment.

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