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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.
1

Financial Decision-Making Models and Royalty Models for BOT Projects

Ting, I-Ting 27 June 2006 (has links)
In recent years, the Build-Operate-Transfer (BOT) project has become a widespread mode for infrastructure construction. The BOT project is promoted to alleviate the government financial pressure and lead in efficiency of the private sector. There were a lot of large constructions to adopt BOT model, such as Taiwan High Speed Rail, Kaohsiung Rapid Transit System, and so forth. Self-liquidating ratio (SLR) is one of the most important indicators in evaluating a BOT project. Since the cash flow structures are different between BOT projects and projects financed solely by government, the original SLR formula is not perfectly suitable. Therefore, this study revises the SLR formula, and tries to use the new definition to construct a financial-decision model for the government and concession company. When the government administration and the concession company negotiate a concession agreement, they have to determine the investment proportion and royalty. However, traditional evaluation model, such as Net-Present Value Method, Internal Rate of Return Method, are rarely focus on the theme. As a result, there is not a appropriate standard to use. This study combines cash flow concept and linear programming method to construct financial-decision models for both sides. We expect to look for a bargain space of investment proportion and royalty. With the bargain space, the participants of BOT project can make a better investment decision, and reduce the wrong policy which may lead the waste of social resources.
2

Tärnstigen

Kramer, Wictor, Kirchhoff, Marcus January 2020 (has links)
När klimatförändringarna tvingar kustnära, utsatta städer och områden till drastiska åtgärder för att bibehålla sin existens, är den stora frågan vad som ska räddas och vad som lämnas till historien. I södra Sverige har Vellinge kommun kämpat sig fram till en åtgärd som kommer rädda flera hundra hushåll från att bli Sveriges egna Atlantis. Stigande havsnivåer kommer tacklas genom konstruktionen av en vall som kommer omfamna majoriteten av den byggda miljön kring halvön. Med ekologiska och ekonomiska men framför allt sociala aspekter bygger detta kandidatarbete på en omgestaltning kring ett 400 meter långt stråk som kopplar samman flera av dessa aspekter och förstärker dem istället för att se dem långsamt tyna bort. Hur kan Vellinge kommuns investering i ett skydd för kommande, temporärt stigande havsnivåer, designas för att även bidra till social hållbarhet?För att kunna besvara kandidatarbetets frågeställning har en research by design såväl som olika fältstudier genomförts i syfte att utforma ett designförslag inom väl avvägda mått för områdets förutsättningar. Genom att utmana hanteringen av globala problematiska situationer till sin fördel har denna studie testat en ny metod och tillvägagångssätt för en designprocess. / When climate change forces vulnerable cities and areas around the coast to take drastic measures to maintain their existence, the big question is what is to be saved and what is left in history. In southern Sweden, the municipality of Vellinge has fought for a measure that will save hundreds of households from becoming Sweden’s own Atlantis. Rising sea levels will be kept away by the construction of a wall that will embrace the majority of the built environment around the peninsula. With ecological and economical but above all social aspects, this Bachelor thesis is based on a design regarding a 400 meter long passage that links several of these aspects together and reinforces them instead of slowly watching them fade away. Thus, the objective of this thesis is to answer the following research question: How can Vellinge municipality’s investment in a protecting embankment for temporarily rising sea levels be designed to contribute to social sustainability? In order to answer the research question, a research by design-model as well as various field studies were executed in order to present a design proposal within the well-balanced measures for the area’s conditions. This study has tested a new method and design process in order to turn the conditions into an opportunity for new design.
3

Thesis Pekarek.pdf

Robert Pekarek (15361783) 26 April 2023 (has links)
<p>  </p> <p>Sea level rise is a growing threat to coastal communities across the United States. Uncertainty about the extent of sea level rise poses a challenge for creating infrastructure to address this threat. Due to disagreement among decision makers on the severity of climate change, it can be challenging to determine the appropriate level of preparation for the future, which can lead to potential under or over-preparedness. To combat this uncertainty, the US Department of Defense has embraced a robust decision-making model. Decision makers should incorporate multiple future models of the world into their decision-making process. This thesis describes an effort to address these challenges at the United States Naval Academy using a decision support approach called many-objective robust decision-making. Considering decisions to upgrade their seawall at varying heights and at twenty-year intervals, a genetic algorithm was employed to identify a frontier of non-dominated upgrade strategies. Three strategies from the frontier were evaluated in hundreds of possible scenarios with varied discount rates, sea level rise projections, changes to future storminess, and building replacement costs. An analysis was performed to determine in which future conditions those three strategies were vulnerable to failing to meet objectives of having a benefit cost ratio of over 1 and limiting damage to less than $100 million over an 80-year planning horizon. This analysis will enable the US Naval Academy to determine the effectiveness of their seawall upgrade plans for preventing storm surge damage over a range of future scenarios and stakeholder preferences. Ultimately, this research found that upgrading the Naval Academy’s seawall in the near future is critical to avoiding costly damage from flooding. This research also emphasizes how variations to the assumed discount rate can reshape a cost benefit analysis.</p>
4

Zur Optimierung der Kombinationsstrategie verschiedener Satellitenbeobachtungsverfahren bei der Realisierung eines globalen terrestrischen Referenzsystems / On the optimization of the combination strategy of different geodetic satellite techniques to realize a global terrestrial reference system

Glaser, Susanne 30 June 2014 (has links) (PDF)
Eine der zentralen Aufgaben der Geodäsie liegt in der Definition und der Realisierung von geeigneten Referenzsystemen. Die Realisierung eines globalen terrestrischen Referenzsystems wird als Referenzrahmen bezeichnet und ist durch Positionen zu einer Bezugsepoche und durch zeitlich lineare Bewegungen global verteilter Stationen festgelegt. Verschiedene Satellitenbeobachtungsverfahren können kombiniert werden, um ein globales terrestrisches Referenzsystem höchstmöglicher Genauigkeit, Stabilität und Konsistenz zu realisieren. Im Rahmen dieser Arbeit fanden dazu GPS- und GLONASS-Beobachtungen der Globalen Navigationssatellitensysteme (engl. Global Navigation Satellite System - GNSS) und Laserentfernungsmessungen (engl. Satellite Laser Ranging - SLR) zu den passiven Satelliten LAGEOS-1 und LAGEOS-2 Anwendung. Die Datengrundlage sind tägliche Normalgleichungssysteme für GNSS und wöchentliche für SLR über einen Zeitraum von 17 Jahren (1994 - 2010). Diese entstammen einer homogenen Reprozessierung, welche unter der Beteiligung der TU München, der Universität Bern, der ETH Zürich und der TU Dresden erfolgte. Dabei wurden Reduktionsmodelle verwendet, welche sich an den aktuellen IERS-Konventionen orientieren. Die verschiedenen Satellitenbeobachtungsverfahren wurden mit der gleichen wissenschaftlichen Software ausgewertet und kombiniert. Die Lösung weist daher eine höchstmögliche Konsistenz auf. In Anlehnung an die Empfehlungen in den aktuellen IERS-Konventionen wurden Auflastdeformationen infolge von Massenvariationen in der Atmosphäre und im Ozean im Auswerteprozess berücksichtigt. Dazu fand ein Modell Anwendung, welches schon bei der Reduktion von Beobachtungen der Schwerefeldmission GRACE (engl. Gravity Recovery and Climate Experiment) genutzt wird. Die Berücksichtigung dieses Modells führt zu einer Verbesserung der Genauigkeit der GNSS- und SLR-Stationspositionen. Da die SLR-Stationspositionen aufgrund eines systematischen Effektes (engl. blue sky effect) leicht verfälscht sind, sollte dieser Effekt berücksichtigt werden. Dies gilt vor allem vor dem Hintergrund einer Kombination der Verfahren zur Realisierung eines globalen terrestrischen Referenzsystems höchster Genauigkeit. Darüber hinaus überlagern weitere nichtlineare geophysikalische Effekte das lineare Modell aus Positionen und Geschwindigkeiten, z.B. die Auflastdeformation infolge kontinentaler Wasserspeicheränderungen. Werden diese Effekte in einer Auswertung nicht reduziert, sind in den ausgeglichenen Parametern sogenannte residuale Deformationen enthalten. Im Rahmen dieser Arbeit wurde daher das lineare Modell erweitert, indem residuale Deformationen in Form einer sphärisch harmonischen Entwicklung parametrisiert wurden. Die daraus bestimmten Grad-1-Auflastkoeffizienten weisen ein starkes jährliches Signal auf, welches sowohl die GNSS- als auch die SLR-Lösung zeigen. Die Kombination von GNSS und SLR erfolgte auf Normalgleichungsebene. Um die individuellen Stärken der Verfahren optimal ausnutzen zu können, wurden für eine gegenseitige Gewichtung der Verfahren realistische Genauigkeitsmaße abgeleitet. Es wurden Stationspositionen und -geschwindigkeiten geschätzt sowie die Polkoordinaten und die Grad-1-Auflastkoeffizienten gemeinsam ausgewertet. Im Gegensatz zu den bisherigen Referenzrahmen wurden keine terrestrisch gemessenen Differenzvektoren (engl. Local Ties - LT) an Kolokationsstationen verwendet, um die verfahrensinternen Lösungen zu kombinieren. Mit einer entsprechenden Definition des geodätischen Datums konnten hingegen Komponenten der LT als Unbekannte aus einer globalen Lösung bestimmt werden. Dies ermöglichte eine unabhängige Validierung der LT, welche einen entscheidenden Punkt in der Kombination unterschiedlicher Verfahren darstellen. / One of the main tasks of geodesy is the definition and realization of reference systems. A global terrestrial reference system is realized by a reference frame of a set of positions which respect to a reference epoch and linear motions of a network of globally distributed stations on the Earth's surface. Different space geodetic techniques can be combined to realize a reference system with optimal accuracy, stability and consistency. As such, the focus of this thesis was to apply GPS and GLONASS of the Global Navigation Satellite System (GNSS) and satellite laser ranging (SLR) to LAGEOS-1 and LAGEOS-2 to determine an improved global terrestrial reference frame. The data are daily for GNSS and weekly for SLR normal equation systems over a time span of 17 years (1994 - 2010), produced from a homogeneous reprocessing. This was done through a joint effort of TU Munich, University of Bern, ETH Zurich and TU Dresden using common state of the art reducing models according to the IERS conventions. The same processing software was used to evaluate and combine the different geodetic systems to ensure the highest consistency. Utilizing the recommendations of the IERS conventions 2010, the displacement of the Earth's surface due to mass variations in the atmosphere and in the ocean was reduced from the observations. A model of the non-tidal part which is also used for the reduction of observations of the geodetic gravity mission GRACE (Gravity Recovery and Climate Experiment) was applied. The reduction of this model enhances the position accuracy of the GNSS and SLR position time series. Because of the systematic effect on SLR observations (blue sky effect) the surface load deformation should be reduced especially when combining SLR and GNSS to realize a global terrestrial system. In addition there are more geophysical effects on the station positions, for example the deformation of the Earth's surface due to continental hydrological loading. If such effects are not considered in the estimation process of geodetic observations, residual deformations are present in the estimated parameters. Therefore, this effort included modeling of deformation in the solution by using a consistent spherical harmonic approach of degree-one surface load coefficients. The residual deformations such as hydrological loading modeled with degree-one surface load coefficients have a strong annual signal for which the GNSS-only and the SLR-only solutions show the same variations. The combination of GNSS and SLR was done at the level of normal equations. Considering the strengths of each technique, an optimal weighting based on more realistic uncertainties was applied to the data. The pole coordinates and the degree-one surface load coefficients were combined. Unique to the most recent realizations of a global terrestrial reference system, no local ties (LT) of co-located sites were used in the combination of the different techniques. Thus, using a global solution together with an appropriate definition of the geodetic datum of the combined station network it was possible to estimate components of LT. This estimation enables an independent validation of the measured LT which are a crucial point in combination of different geodetic techniques.
5

Zur Optimierung der Kombinationsstrategie verschiedener Satellitenbeobachtungsverfahren bei der Realisierung eines globalen terrestrischen Referenzsystems

Glaser, Susanne 28 February 2014 (has links)
Eine der zentralen Aufgaben der Geodäsie liegt in der Definition und der Realisierung von geeigneten Referenzsystemen. Die Realisierung eines globalen terrestrischen Referenzsystems wird als Referenzrahmen bezeichnet und ist durch Positionen zu einer Bezugsepoche und durch zeitlich lineare Bewegungen global verteilter Stationen festgelegt. Verschiedene Satellitenbeobachtungsverfahren können kombiniert werden, um ein globales terrestrisches Referenzsystem höchstmöglicher Genauigkeit, Stabilität und Konsistenz zu realisieren. Im Rahmen dieser Arbeit fanden dazu GPS- und GLONASS-Beobachtungen der Globalen Navigationssatellitensysteme (engl. Global Navigation Satellite System - GNSS) und Laserentfernungsmessungen (engl. Satellite Laser Ranging - SLR) zu den passiven Satelliten LAGEOS-1 und LAGEOS-2 Anwendung. Die Datengrundlage sind tägliche Normalgleichungssysteme für GNSS und wöchentliche für SLR über einen Zeitraum von 17 Jahren (1994 - 2010). Diese entstammen einer homogenen Reprozessierung, welche unter der Beteiligung der TU München, der Universität Bern, der ETH Zürich und der TU Dresden erfolgte. Dabei wurden Reduktionsmodelle verwendet, welche sich an den aktuellen IERS-Konventionen orientieren. Die verschiedenen Satellitenbeobachtungsverfahren wurden mit der gleichen wissenschaftlichen Software ausgewertet und kombiniert. Die Lösung weist daher eine höchstmögliche Konsistenz auf. In Anlehnung an die Empfehlungen in den aktuellen IERS-Konventionen wurden Auflastdeformationen infolge von Massenvariationen in der Atmosphäre und im Ozean im Auswerteprozess berücksichtigt. Dazu fand ein Modell Anwendung, welches schon bei der Reduktion von Beobachtungen der Schwerefeldmission GRACE (engl. Gravity Recovery and Climate Experiment) genutzt wird. Die Berücksichtigung dieses Modells führt zu einer Verbesserung der Genauigkeit der GNSS- und SLR-Stationspositionen. Da die SLR-Stationspositionen aufgrund eines systematischen Effektes (engl. blue sky effect) leicht verfälscht sind, sollte dieser Effekt berücksichtigt werden. Dies gilt vor allem vor dem Hintergrund einer Kombination der Verfahren zur Realisierung eines globalen terrestrischen Referenzsystems höchster Genauigkeit. Darüber hinaus überlagern weitere nichtlineare geophysikalische Effekte das lineare Modell aus Positionen und Geschwindigkeiten, z.B. die Auflastdeformation infolge kontinentaler Wasserspeicheränderungen. Werden diese Effekte in einer Auswertung nicht reduziert, sind in den ausgeglichenen Parametern sogenannte residuale Deformationen enthalten. Im Rahmen dieser Arbeit wurde daher das lineare Modell erweitert, indem residuale Deformationen in Form einer sphärisch harmonischen Entwicklung parametrisiert wurden. Die daraus bestimmten Grad-1-Auflastkoeffizienten weisen ein starkes jährliches Signal auf, welches sowohl die GNSS- als auch die SLR-Lösung zeigen. Die Kombination von GNSS und SLR erfolgte auf Normalgleichungsebene. Um die individuellen Stärken der Verfahren optimal ausnutzen zu können, wurden für eine gegenseitige Gewichtung der Verfahren realistische Genauigkeitsmaße abgeleitet. Es wurden Stationspositionen und -geschwindigkeiten geschätzt sowie die Polkoordinaten und die Grad-1-Auflastkoeffizienten gemeinsam ausgewertet. Im Gegensatz zu den bisherigen Referenzrahmen wurden keine terrestrisch gemessenen Differenzvektoren (engl. Local Ties - LT) an Kolokationsstationen verwendet, um die verfahrensinternen Lösungen zu kombinieren. Mit einer entsprechenden Definition des geodätischen Datums konnten hingegen Komponenten der LT als Unbekannte aus einer globalen Lösung bestimmt werden. Dies ermöglichte eine unabhängige Validierung der LT, welche einen entscheidenden Punkt in der Kombination unterschiedlicher Verfahren darstellen. / One of the main tasks of geodesy is the definition and realization of reference systems. A global terrestrial reference system is realized by a reference frame of a set of positions which respect to a reference epoch and linear motions of a network of globally distributed stations on the Earth's surface. Different space geodetic techniques can be combined to realize a reference system with optimal accuracy, stability and consistency. As such, the focus of this thesis was to apply GPS and GLONASS of the Global Navigation Satellite System (GNSS) and satellite laser ranging (SLR) to LAGEOS-1 and LAGEOS-2 to determine an improved global terrestrial reference frame. The data are daily for GNSS and weekly for SLR normal equation systems over a time span of 17 years (1994 - 2010), produced from a homogeneous reprocessing. This was done through a joint effort of TU Munich, University of Bern, ETH Zurich and TU Dresden using common state of the art reducing models according to the IERS conventions. The same processing software was used to evaluate and combine the different geodetic systems to ensure the highest consistency. Utilizing the recommendations of the IERS conventions 2010, the displacement of the Earth's surface due to mass variations in the atmosphere and in the ocean was reduced from the observations. A model of the non-tidal part which is also used for the reduction of observations of the geodetic gravity mission GRACE (Gravity Recovery and Climate Experiment) was applied. The reduction of this model enhances the position accuracy of the GNSS and SLR position time series. Because of the systematic effect on SLR observations (blue sky effect) the surface load deformation should be reduced especially when combining SLR and GNSS to realize a global terrestrial system. In addition there are more geophysical effects on the station positions, for example the deformation of the Earth's surface due to continental hydrological loading. If such effects are not considered in the estimation process of geodetic observations, residual deformations are present in the estimated parameters. Therefore, this effort included modeling of deformation in the solution by using a consistent spherical harmonic approach of degree-one surface load coefficients. The residual deformations such as hydrological loading modeled with degree-one surface load coefficients have a strong annual signal for which the GNSS-only and the SLR-only solutions show the same variations. The combination of GNSS and SLR was done at the level of normal equations. Considering the strengths of each technique, an optimal weighting based on more realistic uncertainties was applied to the data. The pole coordinates and the degree-one surface load coefficients were combined. Unique to the most recent realizations of a global terrestrial reference system, no local ties (LT) of co-located sites were used in the combination of the different techniques. Thus, using a global solution together with an appropriate definition of the geodetic datum of the combined station network it was possible to estimate components of LT. This estimation enables an independent validation of the measured LT which are a crucial point in combination of different geodetic techniques.
6

Using Road Weather Information Systems (RWIS) to optimize the Scheduling of Load Restrictions on Northern Ontario's Low-Volume Highways

Baiz, Sarah January 2007 (has links)
Covering the Northern part of the Province, Ontario’s low-volume roads provide a link from remote resource areas to markets. Thus, preserving this transportation asset from the two main sources of pavement deterioration, namely traffic loading and the environment is extremely critical to the movement of goods and to the economy. In particular, Northern Ontario’s secondary highways are challenged by a combination of heavy, low frequency traffic loading and a high number of freeze-thaw cycles for which most of these highways have not been structurally designed. Therefore they experience environmental damage and premature traffic-induced deterioration. To cope with this issue, the Ontario Ministry of Transportation places Spring Load Restrictions (SLR) every year during spring-thaw. For economic reasons, the duration of SLRs is usually fixed in advance and is not applied proactively or according to conditions in a particular year. This rigidity in the schedule needs to be addressed, as it can translate into economic losses either when the payload is unnecessarily restricted or when pavement deterioration occurs. While the traditional approaches are usually qualitative and rely on visual observations, engineering judgment and historical records to make SLR decisions, the latest approaches resort to climatic and deflection data to better assess the bearing capacity of the roadway. The main intent of this research was to examine how the use of a predictor for frost formation and thawing could improve the scheduling of load restrictions by tracking the frost-strengthening and thaw-weakening of the pavement structure. Based on field data captured in Northern Ontario, and on a preliminary analysis that found good correlation between frost thickness in the roadway and Road Weather Information Systems (RWIS) variables, more advanced frost and thaw predictors were developed as part of this research and are presented herein. The report outlines how the model was developed, details the calculation algorithms, and proposes an empirical methodology for a systematic site-specific calibration. This research also involved several experimental and numerical tools, including the use of a Portable Falling Weight Deflectometer (PFWD) to estimate pavement strength during spring thaw, and the use of the Mechanistic-Empirical Pavement Design Guide (MEPDG) software to simulate the impact of SLR on the performance of typical Northern Ontario low volume roads.
7

Using Road Weather Information Systems (RWIS) to optimize the Scheduling of Load Restrictions on Northern Ontario's Low-Volume Highways

Baiz, Sarah January 2007 (has links)
Covering the Northern part of the Province, Ontario’s low-volume roads provide a link from remote resource areas to markets. Thus, preserving this transportation asset from the two main sources of pavement deterioration, namely traffic loading and the environment is extremely critical to the movement of goods and to the economy. In particular, Northern Ontario’s secondary highways are challenged by a combination of heavy, low frequency traffic loading and a high number of freeze-thaw cycles for which most of these highways have not been structurally designed. Therefore they experience environmental damage and premature traffic-induced deterioration. To cope with this issue, the Ontario Ministry of Transportation places Spring Load Restrictions (SLR) every year during spring-thaw. For economic reasons, the duration of SLRs is usually fixed in advance and is not applied proactively or according to conditions in a particular year. This rigidity in the schedule needs to be addressed, as it can translate into economic losses either when the payload is unnecessarily restricted or when pavement deterioration occurs. While the traditional approaches are usually qualitative and rely on visual observations, engineering judgment and historical records to make SLR decisions, the latest approaches resort to climatic and deflection data to better assess the bearing capacity of the roadway. The main intent of this research was to examine how the use of a predictor for frost formation and thawing could improve the scheduling of load restrictions by tracking the frost-strengthening and thaw-weakening of the pavement structure. Based on field data captured in Northern Ontario, and on a preliminary analysis that found good correlation between frost thickness in the roadway and Road Weather Information Systems (RWIS) variables, more advanced frost and thaw predictors were developed as part of this research and are presented herein. The report outlines how the model was developed, details the calculation algorithms, and proposes an empirical methodology for a systematic site-specific calibration. This research also involved several experimental and numerical tools, including the use of a Portable Falling Weight Deflectometer (PFWD) to estimate pavement strength during spring thaw, and the use of the Mechanistic-Empirical Pavement Design Guide (MEPDG) software to simulate the impact of SLR on the performance of typical Northern Ontario low volume roads.
8

Investigating the Application of TDD Practice in Large-Scale Industries

DANTULURI, PAVAN KUMAR VARMA, NETHI, RAMAKRISHNA January 2018 (has links)
Context: Developer’s within software companies work chosen choice of software development process. Choice of a particular Software Development Process impacts the work environment, end-product and might also have financial risks due to delay in delivering in the final software product. Objectives: we are investigating if the TDD could impact/applicable in large-scale industries. To achieve that we first identify the strengths and challenges while using TDD in large-scale industries. Identify what modifications can enhance the impact of TDD in large-Scale industries. Methods: Systematic Literature Review (SLR) has been used to investigate the application of TDD in large-scale industries. Using the info from SLR we conducted an online survey for validating the results obtained from SLR. As a last step we have conducted semi structured interviews to gather information from developers across industries practicing and practiced TDD. The data from the qualitative and quantitative methods is triangulated by identifying the strengths, challenges and modifications in applying TDD to large-scale industries. Results: The findings from our SLR, results validated from Survey and responses from interview participants show that TDD have both strengths, Challenges and modifications. Conclusions: Some challenges encountered when using TDD in large-scale industries are Negative test cases, linking test case modules of several developers, Communication, Overall idea about project, lack of TDD knowledge for developers practicing TDD, also lack of automation tools supporting the development of unit test-cases.
9

On the Quality of Grey Literature and its use in Information Synthesis during Systematic Literature Reviews / Om kvaliteten på Grey litteratur och dess användning i Information Synthesis under systematiska litteraturöversikter

Yasin, Affan, Hasnain, Muhammad Ijlal January 2012 (has links)
Context: The Internet has become a vital channel for disseminating and accessing scientific literature for both the academic and industrial research needs. Nowadays, everyone has wide access to scientific literature repositories, which comprise of both “white” and “Grey” literature. The “Grey” literature, as opposed to “white” literature, is non-peer reviewed scientific information that is not available using commercial information sources such as IEEE or ACM. A large number of software engineering researchers are undertaking systematic literature reviews (SLRs) to investigate empirical evidence in software engineering. The key reason to include grey literature during information synthesis is to minimize the risk of any bias in the publication. Using the state of the art non-commercial databases that index information, the researchers can make the rigorous process of searching empirical studies in SLRs easier. This study explains the evidence of Grey literature while performing synthesis in Systematic Literature Reviews. Objectives: The goals of this thesis work are, 1. To identify the extent of usage of Grey Literature in synthesis during systematic literature reviews. 2. To investigate if non-commercial information sources primarily Google Scholar are sufficient for retrieving primary studies for SLRs. Methods: The work consists of a systematic literature review of SLRs and is a tertiary study and meta-analysis. The systematic literature review was conducted on 138 SLRs’ published through 2003 until 2012 (June). The article sources used are IEEEXplore, ACM Digital Library, Springer-Link and Science Direct. Results: For each of the selected article sources such as ACM, IEEEXplore, Springer-link and Science Direct, we have presented results, which describe the extent of the usage of Grey literature. The qualitative results discuss various strategies for systematic evaluation of the Grey literature during systematic literature review. The quantitative results comprise of charts and tables, showing the extent of Grey literature usage. The results from analysis of Google Scholar database describe the total number of primary studies that we are able to find using only Google Scholar database. Conclusion: From the analysis of 138 Systematic Literature Reviews (SLRs’), we conclude that the evidence of Grey literature in SLRs is around 9%. The percentage of Grey literature sources used in information synthesis sections of SLRs is around 93.2%. We were able to retrieve around 96 % of primary studies using Google Scholar database. We conclude that Google Scholar can be a choice for retrieving published studies however; it lacks detailed search options to target wider pool of articles. We also conclude that Grey literature is widely available in this age of information. We have provided guidelines in the form of strategies for systematic evaluation of Grey literature. / Sammanhang: Internet har blivit en viktig kanal för att sprida och få tillgång vetenskaplig litteratur för både akademiska och industriella forskningsbehov. Numera har alla bred tillgång till vetenskaplig litteratur förråd, som omfattar både &quot;vit&quot; och &quot;grå&quot; litteratur. Den &quot;grå&quot; litteratur, som motsats till &quot;vita&quot; litteratur, är icke-vetenskapligt granskad vetenskaplig information som inte är tillgänglig med kommersiella informationskällor såsom IEEE och ACM. Ett stort antal forskare software engineering genomför systematiska litteraturöversikter (systemkameror) för att undersöka empiriska bevis programvaruteknik. Den viktigaste orsaken till att omfatta grå litteratur under Information syntes är att minimera risken för att partiskhet i publikationen. Använda toppmoderna icke-kommersiella databaser som indexerar information kan forskarna göra rigorösa processen att söka empiriska studier i systemkameror lättare. Denna studie förklarar bevis på grå litteratur när de utför syntes i systematiska litteraturöversikter. Mål: Målen med detta examensarbete är, 1. För att identifiera omfattningen av användningen av Grey litteratur i syntes under systematisk litteratur recensioner. 2. För att undersöka om icke-kommersiella informationskällor främst Google Scholar är tillräckliga för att hämta primära studier för systemkameror. Metoder: Verket består av en systematisk litteraturgenomgång av systemkameror och är en tertiär studie och metaanalys. Den systematiska litteraturstudie genomfördes på 138 systemkameror &quot;publiceras via 2003 till 2012 (juni). Artikeln används källorna är IEEEXplore, ACM Digital Library, Springer-Link och Science Direct. Resultat: För vart och ett av de utvalda artikeln källor såsom ACM, IEEEXplore, Springer-länk och Science Direct, har vi presenterat resultat, som beskriver omfattningen av användningen av grå litteratur. De kvalitativa resultaten diskuterar olika strategier för systematisk utvärdering av grå litteratur under systematisk litteraturöversikt. De kvantitativa resultaten består av diagram och tabeller, som visar omfattningen av Grey litteratur användning. Resultaten från analys av Google Scholar-databasen beskriver det totala antalet primära studier som vi kan hitta med enbart Google Scholar databas. Slutsats: Av analysen av 138 systematiska litteraturöversikter (systemkameror) kan vi dra slutsatsen att bevisen för grå litteratur i systemkameror är cirka 9%. Den procentuella andelen Grey litteraturkällor som används i avsnitt informations syntes av systemkameror är cirka 93,2%. Vi kunde hämta omkring 96% av primära studier med Google Scholar databas. Vi drar slutsatsen att Google Scholar kan vara ett val för hämta publicerade studier dock, det saknar detaljerade sökalternativ för att rikta större pool av artiklar. Vi avslutar också att grå litteratur är allmänt tillgänglig i denna tid av information. Vi har försett riktlinjer i form av strategier för systematisk utvärdering av Grey litteratur. / Affan Yasin : Skype id (affan.yasin) Ijlal Hasnain: Skype id (bluesols)
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Determination of geodetic velocity field parameters for the African tectonic plate using the technique of Global Navigation Satellite Systems

Munghemezulu, Cilence January 2013 (has links)
Space geodesy is one of the disciplines that contributes uniquely to the global society; its applications have grown to such an extent that system Earth is better understood today. The current accuracy of the Global Navigation Satellite Systems (GNSS) technique is below centimetre level and this allows very accurate determination of velocity field parameters. This study focused on utilizing GNSS to determine the inter-continental plate velocity field for Africa in support of the African Geodetic Reference Frame (AFREF). Data spanning 12.4 years were processed in the International Terrestrial Reference Frame (ITRF2008) using GAMIT/GLOBK 10.4 (developed at the Massachusetts Institute of Technology). Primarily, processing of data focused on International GNSS Service (IGS) stations with a few non-IGS stations (which are of geodetic quality) included, such as Hamburg (HAMB) and Matjiesfontein (MATJ). The same data set was analysed using the Combination and Analyses of Terrestrial Reference Frame (CATREF) software developed at Institut National de l’Information Géographique et Forestière (IGN). Validation of the results was achieved through comparison of the velocity solution from this study with a solution obtained from a core of IGS GNSS stations processed by the Jet Propulsion Laboratory (JPL). No significant differences were evident between the GAMIT/GLOBK 10.4, CATREF and JPL solutions. The results from the Matjiesfontein station indicated that the proposed Matjiesfontein Observatory site shows no significant vertical or horizontal local motion; this information is valuable in that there is no obvious local site instability. The velocity field as derived by GNSS displays no unexpected deviations and supports current understanding of the motion of the Nubian, Somalian and Arabian plates. Furthermore, the comparison of the velocity vectors derived from the IGS station HRAO, Satellite Laser Ranging (SLR) MOBLAS-6 station and 26 m Very Long Baseline Interferometry (VLBI) telescope, which are collocated at the Hartebeesthoek Radio Astronomy Observatory (HartRAO) indicated good agreement and both techniques exhibit no significant vertical motion. This study also contributed to the first computation of the AFREF solution. It is envisaged that as more stations are added to the sparsely distributed current network, more accurate results and better tectonic models can be derived. The availability of station velocities will facilitate adjustments within the AFREF. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Geography, Geoinformatics and Meteorology / unrestricted

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