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The aim of this thesis is to calculate the primary inter-turn voltage distributions when the medium voltage single phase power transformer is subjected to a step voltage. This culculation is performed by considering the turns of the primary winding as transmission lines. In this thesis, the hybrid model, a combination of single transmission line model and multiconductor transmission line model,is used. Secondly, the interturn voltage distribution is computed for the situation when a medium voltage distribution cable is inserted between the source and the transformer. This distribution cable has to be modeled using a high frequency cable model. The cable is also considered as a transmission line.

The effective thickness of the bedload layer over a river bed can be schematised as the total volume of bedload sediment that is in transport, divided by the surface. In practice, this layer is considered to have a constant thickness over time. Main question of this thesis is whether this assumption is valid. By analyzing the mass balance, it is possible to gain an approximation of the reality. By means of numerical approximations, it is possible to build a morphological model which imitates these equations. This imitation makes it possible to analyze the effect of specific parameters on the sediment transport and the bed surface elevation. In this way, the effect of neglecting the derivative over time of the effective thickness of the bedload layer can be investigated. The model of a river section of the Rhine between Emmerich am Rhein and Lobith results in a maximum influence of the derivative of the effective thickness of the bedload layer on the morphodynamic changes as the result of one flood event that is smaller than 4%. A parameter study makes it possible to test the obtained result on sensitivity. Because the morphodynamic model is based on a lot of input parameters, a well founded choice between the large variety of parameters has to be made. A rough sensitivity test shows that the at maximum 4% influence on the derivative is subject to a possible variation of approximately a factor 2, depending on the variation in the input parameters.

A Strategic plan for OCS was created to expand its business on the Dutch hospital market. By analyzing company, market, competitors and healthcare developments and comparing the findings with the analysis and evaluation of 5 cases concerning hospital construction and renovation projects, opportunities are identified and a strategic direction was chosen. A suitable strategy and business model was developed to compose a roadmap that can be used as a guideline for the company in their pursuit of the new business direction. This strategy was tested on its strategic relevance and feasibility. Key to the new strategy is the implementation of OCS’s inspiration care vision. Attention was paid to the overall brand image of the solution as this new concept will form the basis for a second business direction for OCS. Because of the small size of OCS a decision was also made about the scale of the primary market and potential partners were identified and partnering scenarios were evaluated.

Introduction Dong Lam Cement Factory is developing a new clinker plant in Thua Thien-Hue Province, Vietnam. The clinker has to be exported towards Ho Chi Minh City, where it is grinded into cement and used for the construction industry. For the clinker production coal is needed and has to be imported. To make the in- and export possible a new dedicated seaport is required to allow for 15,000 dwt clinker vessels and 7,000 dwt coal vessels. Objective The objective is to design a port with sufficient capacity to handle the predicted cargo flow and which offers acceptable conditions for the ships to enter. The effective berth and hinterland capacity have to be determined such, that turnaround times are within limits. To create safe conditions, the vessels need to have enough space for manouevring in the wet port area. These manoeuvres can be seriously disturbed by wind, wave, currents and siltation on the long term. To ensure the workability of the port these effects have to be limited. Analysis To determine the effective berth capacity the queuing theory is applied. In phase 1 and 2 one clinker and one coal berth satisfy with effective capacities of respectively 700 and 175 t/h respectively. In phase 3 two clinker and two coal berths are needed with the same loading/unloading rates. To get insight in the environmental boundary conditions, field data is collected and analysed thoroughly. In Vietnam the wind climate is governed by the South-East Asian monsoon system, with a dominant SE direction and strong NNE winds. The wave climate is directly influenced by the wind climate and shows a similar pattern. With regard to extreme conditions, once a year a tropical storm lands in the vicinity of the port site. These storms are accompanied by strong wave conditions, coming from E to SE direction. Having frequent waves from the NNE and SE, littoral transport is generated in north- and southward direction. Nevertheless, the northward transport is clearly dominant. Currents are heading SE for most of the time. Synthesis Four different layouts are developed for phase 3 of the project. Two of them are dismissed in an early stage, because of unfavourable conditions. The other two layouts – the 'coastal' and 'offshore' alternative, are evaluated with a cost-value approach. In this approach the value of each design is assessed by means of a MCA. Evaluation The following criteria are taken into consideration: navigation, tranquillity at berth, coastal impact, sedimentation, ease of cargo handling, safety and flexibility. Regarding navigation and wind, wave and current hindrance, no significant differences are found. It turns out that the most important difference is found in the coastal impact. The coastal alternative will cause erosion along 7.5 km of coastline with a maximum retreat of 100 m. Instead, the offshore alternative affects 'only' 3 km with maximum retreat of 70 m. The other element of the cost-value approach is the costs. The investment costs for the coastal alternative are 64.1 M$, which include the dredging works, breakwater and quay construction. The costs for the offshore port amount 77.5 M$, which entails the dredging works, breakwater, jetty quay and trestle construction. The relative low costs for the coastal alternative are achieved by applying the cut-and-fill balance; the dredged sand is used as breakwater foundation. Maintenance dredging costs are 1.75 M$ and 0.9 M$ for respectively the coastal and offshore alternative. To finish the cost-value approach the value/costs ratio is taken for both port layouts. The coastal alternative (0.9) turns out to be a better port layout than the offshore alternative (0.77).

Seiches zijn opslingerende staande golven die in afgesloten havenbekkens kunnen ontstaan, wanneer vanaf zee golven met specifieke golflengtes de haven binnen dringen. In het Europoortgebied ontstaat een afgesloten bekken wanneer de stormvloedkering in de Nieuwe Waterweg en de Hartelkering worden gesloten. Seiches veroorzaken een extra verval over de stormvloedkering. Bij de Rijkswaterstaat (dienst Weg- en Waterbouwkunde (DWW) bestaat de vraag naar een ééndimensionaal waterbewegingsmodel waarmee seiches in het Europoortgebied kunnen worden weergegeven. De DWW heeft al een eendimensionaal model (ZWENDL) voor de berekening van seiches in gebruik, maar met name de modellering van de zeerand is in dat model nog niet correct. De amplitude van seiches wordt gedempt door uitstraling van energie naar zee, door wrijving en wervelvorrning en door overdracht van energie naar hogere harmonischen. De laatste drie hydrodynamische dempingsmechanismen warden zonder verdere modelvorrning berekend door niet-lineaire termen in de langegolfvergelijkingen. Dit onderzoek concentreert zich op de juiste weergave in een eendimensionaal model van de uitstraling van energie naar zee door rniddel van het opleggen van een correct gedefinieerde randvoorwaarde op de open rand in het model. In het rapport is aangenomen dat de uitstraling van energie naar zee correct wordt weergegeven door de Sommerfeld uitstralingsvoorwaarde. Deze uitstralingsvoorwaarde verondersteIt dat een golf komende uit een havenmond, zich radiaal expanderend voortplant en dat ver van deze havenmond de amplitude van de golf naar nul afneemt. Op de open rand in het gebied (op oneindig grote afstand van de havenmond) zijn dan alleen uitgaande golven aanwezig. De onderhavige studie heeft als doel het vinden van een antwoord op de volgende vraag: • Indien wordt aangenomen dat een ééndimensionaal model geschikt is voor het weergeven van seiches, is dan ter plaatse van de open rand in het model een randvoonvaarde te definieren, zodanig dat de uitstraling van energie naar zee door die open rand correct wordt gemodelleerd? Uit het onderzoek is geconcludeerd dat de uitstraling van energie naar zee goed wordt gemodelleerd indien de 8-rand als randvoorwaarde wordt opgelegd op de open rand in het model. Het voordeel van de 8-rand is dat deze randvoorwaarde eenvoudig te implementeren is in een eendimensionaal model. De beperking ervan is echter dat alleen de voorafvastgestelde piek in de amplificatiefunctie op een bepaalde locatie in het bekken goed wordt berekend. Daarom wordt aanbevolen om bij gebruik van de 8-rand in een ééndimensionaal model niet een combinatie van frequenties op te leggen, maar slechts een enkele frequentie. Eventueel kan op de open rand een waterstand worden opgelegd. Uit de berekerung volgen dan frequenties waarbij opslingering optreed. Rondom de opgespoorde frequentie moet de berekening opnieuw worden gemaakt, maar dan met een 8-rand als randvoorwaarde opgelegd op de open rand. De (benaderde) plaats van de resonantiefrequentie wordt dan berekend met een waterstandsrand als randvoonvaarde. De hoogte van de amplificatiefactor ter plaatse van de resonantiefrequentie echter wordt verkregen uit een berekening met een 8-rand als randvoorwaarde. De algemene conclusie uit het onderzoek is dat een ééndimensionale modellering van seiches wel mogelijk is, maar dat een betere modellering waarschijnlijk wordt verkregen door een tweedimensionaal zeegebied aan het havenbekken te koppelen.

When designing a new port it is important to predict the operation efficiency of the port. In this respect, it is desirable to predict the possible downtime of a new port in an early phase of the design process. Downtime depends strongly on the moored ship motions. In the past decades several numerical models were developed to predict the behaviour of moored ships in waves. They are referred to as Six Degree of Freedom (SDF) models. These models, such as TERMSIM and BAS, are complex and require quite detailed input data. This detailed information is not available in the planning phase of a new port. Consequently, it is desirable to estimate possible downtime by means of a simple model that estimates the ship's behaviour without detailed input data. With this in mind Delft University of Technology started a research programme that consists of a number ofMSc- projects possibly leading to a PhD-project. The research objective of the programme is to investigate the possibilities of simplification of the models used nowadays. In this respect the aim is to find straightforward relationships to describe the behaviour of moored ships subjected to incident waves. It is emphasized that this simplified model is not meant to replace the Six Degree of Freedom models. The simple model is a valuable design tool, to be used in an early stage of the port development process. This report covers one of the MSc-projects defined as "The analysis of model measurements concerning the behaviour ofmoored ships in long wave ". It concerns the model tests of the planned "Coega Harbour" in South Africa. Part of this project is carried out in South Africa, at CSIR (Council for Scientific and Industrial Research), where data of the model tests are available. The aim of the project is to gain insight in the importance of the various parameters and their mutual relations. An important issue is the validation of relationships mentioned in the literature. The main objective is to derive straightforward relations between motions of a moored ship and the wave field near the ship. Hypotheses with regard to the surge, sway and roll motion are derived from the theory of a moored ship. These hypotheses are verified using the data measured in the physical model. This data is limited to one type of ship moored with one type of mooring system inside one specific harbour. Consequently, the conclusions do not contain general validity. Nonetheless, the results present tools that contribute to the understanding of the response of a moored ship to incident waves.

In dit project wordt vervuilingstransport in kustwateren door diffusie en advectie gemodelleerd. Het is mogelijk dit te doen met behulp van numerieke modellen die zijn gebaseerd op gediscretiseerde partiele differentiaalvergelijkingen. Maar in dit project is gekozen voor een deeltjesmodel. Dit deeltjesmodel is makkelijk en snel te implementeren. In het model hoeft bijvoorbeeld geen rekening gehouden te worden met negatieve concentraties, problemen met massabehoud en steile concentratie gradienten, wat wel het geval is bij de numerieke methoden. Er is eerst onderzoek gedaan naar de basiskennis die bestaat uit deeltjesmodellen, stochastische differentiaalvergelijkingen, de Fokker-Planck vergelijking, numerieke methoden en simuleren. Vervolgens wordt het model opgesteld voor het deeltjes-transport, dat bestaat uit vier stappen, het advectie-diffusie model; de stochastische differentiaalvergelijkingen; het gediscretiseerde model; achterwaarts model dankzij de Kolmogorov-backward vergelijking. De implementatie wordt besproken en het gebruik van SIMONA. Tenslotte wordt het model toegepast op een testcase. Hierbij worden resultaten gepresenteerd voor drie verschillende kritieke locaties. In twee dimensies is al vaak gekeken naar de verspreiding van deeltjes. Hierbij werd vaak gestuit op problemen. Het blijkt moeilijk om rekening te houden met variaties in diepte en waterhoogte. In dit project is gekozen voor een drie dimensionale aanpak om te kijken of hier geen onvoorziene problemen ontstaan. Dit is niet gebeurd, dus alhoewel er met een dimensie meer moet worden gewerkt, blijkt dit toch makkelijker te zijn dan met twee dimensies werken.

Bed degradation in a number of Dutch river branches, like the Bovenrijn, can cause various problems in the near future. At low waters the navigation depth at the non-erodible layer near Emmerich can become too small. Other problems could be lower ground water levels and stability of structures in and near the river, like groynes. To diminish negative effects of bed degradation, nourishing material can be an effective solution. For a better understanding of nourishment behaviour and a better prediction of nourishment propagation, a tracer nourishment released in Germany in 1996 has been modelled and compared with field data. This tracer nourishment was released in the river Rhine at Iffezheim, Southern Germany, chainage kilometre 336. Propagation of this tracer has been recorded to approximately 60 kilometres downstream of the dumpsite. The model used in this research, is a quasi-3D model with a graded sediment module. Simulating with a graded sediment module is important, since the mixture of the tracer nourishment modelled is different from the original bed material and there is an interest in the difference in behaviour between the finer and coarser tracer fractions. A quasi-3D format is used, because spatial scales less than the river width and transverse sorting effects might be important, as well as the parameterization of important 3D effects, like spiral flow. For the description of sediment transport a modified Meyer-Peter-Müller formula is used, the sediment balance of the river bed is described by the model of Hirano. Hiding and exposure effects are implemented by the formulation of Egiazar off, modified by Ashida & Michiue. The bed load transport vector is adjusted by formulations for the effects of spiral flow and transverse bed slope. The roughness is calibrated against the water level for several relevant discharges. The sediment transport formula is calibrated against the yearly sediment transport. The discharge is schematized in two ways: either a constant representative discharge that yields the same yearly transport, or a hydrograph with five different discharge levels is used. Results of case studies show that the thickness of the active layer, hiding and exposure effects and the discharge schematization are important parameters for propagation of the tracer nourishment. Hiding and exposure effects appear to be quite different for a number of existing formulations. Simulation with a hydrograph instead of a constant representative discharge shows important differences: the propagation speed of specific sediment fractions is different. The coarsest fractions move just a little bit, but are still hardly mobile, though not completely immobile as in the computations with the constant representative discharge. Compared to the field data, the finer fractions propagate too slowly, but the coarser fractions hardly move at all. To change this, relevant parameters that can be changed within the model concept used are the active layer thickness, critical Shields value and hiding and exposure relation. It is uncertain however, if the model concept used can represent a satisfactory approximation of the behaviour of all nourishment fractions simultaneously. A number of physical processes that occur in the river reach just downstream Iffezheim, are not included in the model concept. Significant dunes appear to be present in this river reach, introducing vertical and horizontal sorting processes and different hydrodynamic conditions. Furthermore, it is questionable if the critical Shields value should not be variable with the sediment diameter. Finally, navigation appears to be possibly important. Development of a model which takes into account these physical considerations could be beneficial for prediction of sediment nourishments. On locations where nourishment could be an effective solution, field data of the propagation of specific tracer fractions could give important information for rough estimations of nourishment behaviour.

Many morphological models that are in use today, make use of spatially constant grain sizes and bed roughness. Application of this spatially constant grain size and bed roughness is not a correct representation of reality. When making use of actually measured grain sizes, the prediction of the morphological changes does not necessarily improve. Linear analyses of the application of spatially varying grain sizes show that the spatial variation of grain sizes can have much impact on the bed topography in rivers. Two different linear analyses have been conducted by Mosselman & Sloff (1998) and Sieben (2000). One shows a difference in the length and dampening of the bed perturbations due to free excitation. The other shows the existence of a response in the bed topography like a superimposed waveform, due to forced excitation. Implementation of the spatially varying grain size resulted for Olesen's experiment (1985) in effects according to free and forced excitation. For the models of the Waal bend at Nijmegen and Pannerdense Kop, the effects were according to forced excitation. Both linear analyses show morphological effects due to the spatially varying grain size as well as due to spatially varying bed roughness. The spatial variation of the bed roughness should, according to the analyses, have a counteracting morphological effect in regard to the morphological effects of the spatially variation of the grain size. Application of spatially varying bed roughness resulted for Olesen's experiment in effects according to free and forced excitation. For the other two models the implementation of spatially varying bed roughness resulted in effects according to forced excitation. Implementation of a grain size distribution which has reached an equilibrium state leads to a bed level response according to free excitation. While the implementation of a grain size distribution which has not reached an equilibrium, like in rivers with variable discharge, leads to a bed level response according to forced excitation. Implementation of an alluvial bed roughness predictor led to no satisfactory results for Olesen's experiment and the Waal bend at Nijmegen. However, for the model of Pannerdense Kop the results of the computation matched the prototype better than the computation with uniform grain sizes and bed roughness. This was caused by two main effects. The first was a forced excitation due to the spatially varying bed roughness. The second was a change in the sediment distribution at the bifurcation.

The first one who studied the problem of armour layer stability was Iribarren (1938). Iribarren derived stability criteria that were based on the acting physical processes on the slope of a structure. In the stability criteria of Iribarren only the influence of a few structural and hydraulic parameters were taken into account. In 1988 Van der Meer derived a stability relation in which the stability of armour layers was depending on several hydraulic and structural parameters. Van der Meer concluded that the stability of armour layers is strongly influenced by the composition of a structure. He implemented the influence of the composition of the structure in a permeability coefficient, P. This permeability coefficient is defined for four different structures. Vander Meer is a good tool for the design of armour layers, it has little physical background. The empirical character of the stability relation is found back in the definition of the permeability coefficient. If a different structure is designed than tested by Van der Meer, an estimation of this permeability coefficient has to be made. Since the permeability has large influence on the stability, new methods should be developed to calculate armour layer stability. Due to the irregularity of armour stones it would take a lot of effort to obtain a full analytical solution for the problem of armour layer stability. However, a good attempt into the direction of an analytical solution can be made, since good models are available that describe the water motion on and in coastal structures. An example of such a model is the model ODIFLOCS. ODIFLOCS stands for Qne dimensional flow Qn and in foastal structures. With ODIFLOCS it is possible to calculate the velocities on a coastal structure for certain hydraulic and structural parameters. With these velocities the hydrodynamic forces on the stones in the armour layer can be calculated. Iribarren (1938) proposed a model for armour layer stability. He assumed a hydrodynamic drag force that act on a stone, which is caused by the run-up or run-down, parallel to the slope of the structure. Two stability criteria for the stability of rock on a slope can be distinguished, which are upward and downward stability respectively. The drag force can be written as a function of the velocity on the slope of a breakwater. Iribarren was not able to calculate these velocities, since no models were available to calculate them, and estimated them by wave celerity in shallow water. Van den Berk (1999) was able to proceed the approach of Iribarren and calculated the velocities with the numerical model ODIFLOCS. He modelled homogeneous structures and calculated the armour layer stability for homogeneous structures for several hydraulic and structural conditions. He found that his results and the results ofVan der Meer were strongly correlated. In this research a next step will be made to see whether physical background can be given to the influence of structural permeability on armour layer stability. Structures with different permeabilities will be modelled and the velocities on the slope will be calculated for different hydraulic conditions. With the use of these velocities, which will be calculated with the numerical model ODIFLOCS, the stability can be determined. The test showed that the strongest increase in stability was found for gentle slopes in combination with low and high wave steepness. The test with steep slopes gave significant lower influence of structural permeability, compared with gentle slopes, on armour layer stability. This is contradicting with the findings of Van der Meer, who found a strong influence ofpenneability on the stability for high values of the surf similarity parameter. This shows that the penneabilities that are modelled in this research do not correspond to those tested by Van der Meer.

In 2009 TomTom developed a model, called the MFM-model, which should reflect the maturity, feasibility and progression of a Personal Navigation Device software integration project. However, this model did not reflect all required aspects of the integration project and therefore was unable to correctly reflect the maturity, feasibility or progression. Furthermore, creating and maintaining this model proved to be too time-consuming. In this thesis we identify the problems of this model, propose a number of improvements to eliminate this problems and explain how these improvements have been implemented. In addition, we discuss how the model can be automatically generated from Jira and Perforce in order to reduce the required effort for creating and maintaining it. As an end result, this thesis will deliver a MFM 2.0 prototype which is an automated and improved version of the initial model. We will review this prototype by comparing survey-results taken at the initial situation and the improved situation. To further inspect this prototype, a small case-study is performed to analyze the accuracy, usage and importance of it.

In coastal engineering waves often play a dominant role. To predict the wave behaviour in coastal regions numerical wave propagation models have been developed. This study deals with the verification of two models against measurements in the field, namely HISWA and SWAN. The second generation model HISWA has already proven to perform well for both engineering and research purposes. The third generation model SWAN is a new model, still under development. Also made by Delft University of Technology, SWAN is more or less the improved sequel to HISWA. Both models are based on the action density balance, which is made stationary to reduce the required computer capacity. They simulate wave growth and decay accounting for wind input, bottom friction, depth limited wave breaking, and whitecapping. The main differences between the models are the fact that SW AN is spectral both in frequencies and in directions, whilst in HISWA the frequencies are parametric. Secondly, the numerical scheme in SWAN for the wave propagation is unconditionally stable and encompasses waves from aU directions (360°). In HISWA the directional sector wherein wave propagation is considered is limited to a maximum of 1200 to obtain stability. Furthermore - being third generation - SWAN allows the spectrum to develop without any a priori constraints. During the measuring campaign, which was carried out by the Coastal Research Station Norderney, in the winter of 1995-1996, nine Waverider buoys recorded wave data. These buoys were located in the Norderneyer Seegat, a Wadden Sea area. Two cases have been simulated with SW AN and HISWA: one during high tide and one during low tide. I varied several parameters to examine the influence on the wave heights. These variations concern wind input formulation, wind speed, nonlinear wave wave interactions, friction, breaking, whitecapping, water level and incoming wave height. With reference to these research runs a set of input parameters is composed with which the models perform best in the area of this research. Both models tum out to have a good performance indicator (>90%). It has been found that the wave heights are to a large extent determined by the wind and by breaking. The wave height of the incoming wave at the seaward boundary of the computational domain is of minor importance. In equal circumstances, SWAN tends to calculate higher wave heights than HISWA. It appeared from this study that SWAN performs slightly better than HISWA and is therefore a suitable tool for wave prediction in a Wadden Sea area.

The research carried out had the objective to find additional means of income for the Hague Justice Portal (HJP), a website owned by the Hague Academic Coalition (HAC) which is composed of eight different members. The increasing dissatisfaction felt at the HAC (members) and the municipality of The Hague regarding the HJP’s failure to find other means of income, besides the funding from its members and the municipality, was the stimulus for this research. Several issues surround this objective with the main factors being the following; the HAC members have the feeling that the HJP adds little value to their organization, thus they provide little support. This leads to a level of inactivity resulting in the HJP having a static business model, resulting in no success of finding additional means of income. Furthermore the current subsidy to the HAC stops by the end of 2011 and how or if it is continued remains unknown. The HAC members are not the only stakeholders for finding additional means of income, the total network of content suppliers, funding agencies, visitors, technology providers and advertisers need to be considered to achieve this objective. For this reason the following research question has been raised and answered: How can a business model for the Hague Justice Portal be designed which fits and meets the constraints and objectives, and is feasible? After carrying out the stakeholders-, external business- and visitor analysis it followed that advertisers are most eligible to meet the goal of finding additional income. Visitors are unlikely to be a source of income since the majority are either still studying, doing an internship or just started a job and thus have little budget to spend. More so since the most popular services for this user group are the vacancies and event calendar, which can also be found elsewhere for free, although some aggregating needs to be done. Visitors have shown to be interested in certain parts of the HJP, and not use the HJP as a total product which greatly reduces chances of making them pay. Public organizations need to lower their expenditure, thus also for subsidizing organizations, and rather focus on cooperation. By understanding the limitations surrounding HJP, it became possible to develop design options with the intention to find income but also to enhance the HJP, acting as a catalyst for the income generating design options. A clear distinction could be seen between the design options requiring or benefiting from a new Content Management System (CMS) and those who didn’t. For many of the HJP improvement design options, not only the HAC (members) would benefit, on the contrary, those benefiting the most are the other stakeholders. This on itself is no problem once accepted that the HJP is there for the visitors who may also be the HAC (members) itself. Instead of pushing the HJP onto the market the demand from the various (paying) stakeholders should be central. The distinction between the design options led to the development of three scenarios; 1) keep the current CMS and do little with advertisements, 2) keep the current CMS and maximize advertisement income and 3) get a new CMS and realign the business and IT in order to achieve the objective of generating additional income. Scenario 1 will result in support dropping of visitor numbers within 1 to 2 years and possibly lead to the closure of the HJP. Scenario 2 (estimated yearly costs €108.750,-) tries to maximize advertisement income (estimated €15.000,-) by catering to advertiser demands but also by doing so for the visitors, the HAC (members) and the HJP. Although income generation will be likely, this will be depended on the amount of action undertaken by the HJP and HAC (members). Scenario 3 (estimated yearly and investments costs €100.150,- and €33.000,-) is the most desirable state since for the HJP when decided upon can last for several years and tackle many of the issues found and should lead to additional income (estimated €27.500,-) and added value for the HAC (members). Discontinuing the HJP will result in a tremendous drop in expenditure for the HAC, several pleased HAC members as they will no longer be required to fund the HJP and support for the HAC from the municipality of The Hague will go down. If the HJP wants to generate more income, the HJP, its editors, the HAC and its members will need, to adjust the mainly academic focus and also include a more commercial one. It is unlikely that HAC (members) would like to commit themselves of taking the step towards scenario 3 at once, considering the uncertainty of income being generated, them receiving added value, the commencement of the new Institute of Global Justice and the continuation of the subsidy from the municipality of The Hague. Instead a process is recommend by implementing the recommendations of scenario 2, and together with more clarity of the uncertainties and risks, use the outcome of this process as input for a ‘go / no go’ decision moment. Knowledge gathered prior to this moment could be used as input for a new HJP once a decision has been made. Other options besides continuing with scenario 3 are to continue in a ‘lighter’ version requiring less budget, cooperate with the IGJ or to stop.

This study contains two topics which are important for the use of a one-dimensional computer model, calculating morphological changes in time. Firstly, for a good prediction of the morphological changes by the model a good reproduction of the water movement and the sediment movement is necessary. One of the conditions for a good reproduction of the process is a good schematisation of the river cross-section in the model. In the river cross-section, a good reproduction of all the parameters playing a role in the morphological process is required. Several schematisation-methods are treated, considering a fluctuation in the discharge and irregularly shaped cross-sections. The second topic of this study considers the interpretation of the calculated morphological change to the real cross-section. The calculated morphological change is distributed over the width of the cross-section in several ways, each distribution with his own physical background. The results show an influence of the distribution-option on some practical parameters. For both topics data are used of the Da River in Vietnam and of the River Waal in the Netherlands.

With the advancement of solution techniques and solving computers, 3D analysis of civil engineering problems has increasingly become more interesting. The multiple spring model is one of the tools to give good solutions to 3D liquefaction analyses. In this model, the deviatoric stress is determined in a finite number of springs distributed over virtual planes in the soil element for which liquefaction analysis is to be undergone. Among the several options for the distribution of the virtual planes in the soil element, it was previously found that an icosahedral distribution results in an isotropic model. For the displacement based analysis which is going to be discussed in this report, the global strains will be decomposed into one-dimensional strains in each spring through transformation matrices. Then the Masing rule after several modifications will be used to obtain stress ratio from those transformed strains. The product of the stress ratio and the mean effective stress gives the shear stress in each spring. The global shear stress of the soil mass is calculated from the shear stress in each spring through transformation matrices. The model also uses stress-dilatancy relationships to calculate volumetric strain due to dilatancy which enables to calculate the volumetric strain due to consolidation. Expressions for a curve of isotropic compression or swelling help to calculate the mean effective stress. Along with the stress ratio, it is this mean effective stress that will be used to calculate the shear stress in each spring. In this report, it is discovered that the icosahedral distribution of planes results in an isotropic behavior. However, the way the springs are oriented on those plane as described in the original model by Nishimura (2002) will not result in an isotropic behavior. At the end of the report, suggestions will be given to overcome this anisotropy. It will also be seen that the volumetric strain due to dilatancy is overestimated in the model. The source for the overestimation is discovered and will be forwarded for further improvement. Suggestions for the modification of the hysteresis loop when the stress ratio in the past is exceeded will also be given.

De Dienst Weg- en Waterbouw van Ri jk.swaterstaat en de Sectie Geotechniek. van de Technische universiteit Delft zijn gezamenlijk een onderzoek gestart naar de stabiliteit en het deformatiegedrag van weg- en di jklichamen. Daar veldonderzoek kostbaar en zeer tijdrovend zou zijn, is besloten om modelonderzoek te doen in de geotechnische centrifuge. Indien men een 1 op 100 schaalmodel wil maken, dient de valversnelling met een factor 100 verhoogd te worden, om de grond spanningen op een juiste wijze te modelleren. Dit is mogelijk met behulp van een geocentrifuge. Uit literatuuronderzoek bleek dat bij veel centrifugeproeven de meetresultaten niet in overeenstemming waren met de berekende waarden. Dit kon in veel gevallen worden verklaard doordat ten eerste de kleibodem op onjuiste wijze werd vervaardigd, en ten tweede het aanbrengen van ophogingen en het meten van de schuifsterkte niet altijd tijdens het centrifugeren plaatsvond. In de centrifuge van de Sectie Geotechniek bevinden zich een zandstrooier, om in de vlucht een ophoging te bouwen, een video-camera, een vane-apparaat en een twee-dimensionaal belastingsapparaat om kracht- of vervormingsgestuurde proeven uit te voeren. Met het vane-apparaat kon het schuifsterkte gedrag van klei volledig worden vastgelegd, hetgeen leidde tot een aangepast Mohr-Coulomb model. De gemeten bezwijkkracht van een kleibodem tijdens bulldozerproeven kon goed worden voorspeld met dit schuifsterktegedrag. Met oedometerproeven kon het vervormingsgedrag van de gebruikte kaolin-klei worden beschreven. Door dit vervormingsgedrag te combineren met het schuifsterkberekeningen kon met behulp van eindige-elementen berekeningen het krachtsverloop tijdens het wegdrukken van een plaat zeer nauwkeurig worden verklaard. Ook het moment en de wijze waarop ophogingen bezwijken is met het schuifsterkte gedrag goed uit te rekenen. Er wordt daarom aangeraden om bij normaal-geconsolideerde klei voortaan met een aangepast Mohr-Coulomb model te werken. Geadviseerd wordt om vervolgonderzoek in het beginstadium kleinschalig te houden. Het geheel overziend mag geconcludeerd worden dat met geocentrifugeproeven een brug kan worden geslagen tussen rekenmodel en praktijksituatie.

In modern day society concern is growing about the use of fossil fuels to meet our constantly rising energy demands, and the need for more sustainable energy is growing. Wind energy certainly has the potential to play a significant role in a sustainable future world energy supply and the wind power industry has grown to a globalized multi billion dollar industry. Manufacturers do not only compete with each other, but also with the traditional fossil energy sources. In order to come out on top, manufacturers are aiming at lowering the total turbine costs in order to lower the cost of renewable energy. An important way of achieving this is by reducing the total weight of turbine, by optimizing the design of each individual component. This causes a chain reaction of benefits as less material is used, transport and installation is made easier, a smaller foundation can be used and so on. On the downside, these optimized turbine designs generally introduce more flexibility to the structure. As a result, components start to exhibit local dynamic behavior, which can lead to increased component loading and decreased reliability. However, the aero-elastic models commonly used in wind turbine engineering are often incapable of predicting these local dynamic effects and their interaction with the global dynamics, due to their relatively few degrees of freedom and geometric simplifications. Therefore, a need exists for more detailed structural dynamic analysis tools, without losing generality and versatility. In this thesis the paradigm of dynamic substructuring is proposed to fill this need for detailed dynamic analysis tools in wind turbine engineering. Dynamic substructuring is a way to obtain the structural dynamic behavior of large and/or complex structures by dividing them into several smaller, simpler substructures (or components) of which the dynamic behavior is generally easier to determine. The dynamics of the total structure are then obtained by assembling the dynamic models of the components. A number of different techniques can be distinguished within the field of dynamic substructuring. In this thesis the emphasis is on the application and theory of Component Mode Synthesis techniques. The theoretical contributions are discussed first. Firstly, a general framework for substructure assembly is presented. In addition to the classic “primal” or “dual” assembly of interface displacements, this framework allows to assemble interface forces in a similar “primal” or “dual” manner. Furthermore, the framework enables the direct assembly of interface displacements and interface forces. The latter is called “mixed” assembly. In other words, direct assembly of stiffness matrices with flexibility matrices. Secondly, all common component model reduction techniques (Craig-Bampton, Rubin, etc.) and the relatively new Dual Craig-Bampton method are discussed. The Mixed Craig-Bampton method is introduced in this work and is a true generalization of the Craig-Bampton and Dual Craig-Bampton methods. It is shown that the accuracy of the Mixed Craig-Bampton methods is always in line with the Craig-Bampton and Dual Craig-Bampton methods, thereby emphasizing its versatility. Furthermore, a number of interface modeling strategies are discussed. Firstly, to enable assembly using only six degrees of freedom per interface, interface rigidification is discussed. A second option is to model the interface as fully flexible and retain all its degrees of freedom, which could result in incompatible substructure meshes. To overcome this issue several methods for assembly of non-conforming meshes are discussed. Finally, modeling of dynamic effects resulting from the interface itself (e.g. dynamic behavior of a bolt connection) is also presented in this thesis. Finally, interface reduction techniques are presented. Reduction of interface displacements is already well known from literature. On the other hand, reduction of interface forces, which is also presented in this work, has not been found in literature. It is shown that both methods are able to significantly reduce the number of degrees of freedom of the (reduced) substructure models. Using these methods and techniques, a dynamic substructuring analysis is performed using different reduced component models of the yaw system of a 2.3 Megawatt Siemens wind turbine. All the substructure components are modeled using the finite element method, but due to time limitations only one of the components is validated through measurements. By using the different component model reduction techniques, we were able to reduce the total number of degrees of freedom from almost 300.000 to approximately 750 for the entire yaw system, while maintaining an accurate model of the dynamic behavior for the frequency range of interest. From these results one can conclude that the dynamic substructuring approach shows great potential for use in wind turbine engineering. Even though some models are significantly simplified and not all the models used here are validated, it is clear that the techniques presented in this thesis allow for creating compact and accurate descriptions of the dynamic behavior of wind turbines. Nonetheless several challenges, with respect to non-linear models, controller models and others, are still to be met in order to generalize the methodology for application in wind turbine engineering.

Waves that approach the coast and encounter obstacles such as small islands, rocks or breakwaters may be reflected backwards and in lateral directions, but the wave crest may also bend around the obstacle. This phenomenon can be described with refraction-diffraction models based on the Boussinesq equation or the mild-slope equation of Berkhoff. However, these models are computationally very demanding since they require a high spatial resolution. Moreover, physical phenomena such as wind generation or depth induced breaking are not readily accounted for. Inclusion of diffraction in a spectral wave model would eliminate these drawbacks. Similar to refraction the effect of diffraction can be represented as a transport of wave energy through spectral space (in the directional domain). Two ad hoc proposals are made to include diffraction in the model SWAN, which is a fully spectral model based on the action balance equation. The first proposal to describe this diffraction-induced turning rate is derived from the mild-slope equation for monochromatic, long-crested waves. It depends on the second order spatial derivative of the wave amplitude. Adding the diffraction term made the model unstable. The second proposal to describe the diffraction-induced turning rate is based on the first-order spatial gradient of the wave field. The transport of wave energy along the wave crests is proportional to the first-order derivative of the energy along the crest. The model is tested for three different cases: the academic case of monochromatic, unidirectional waves near a semi-infinite breakwater, a realistic harbour and the Bay of Viano do Castelo (Portugal). In areas with considerable wave motion the influence of diffraction is relatively unimportant. In other regions the gradientapproach for diffraction seems to give a realistic estimate for the wave field.