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The main topic that is researched in this study is: what performative architecture is and its role in the design process and product. In the scope of performative architecture the aim is to focus what a building does rather than what it is and the fact that architecture should have the capability of being adaptable to changing time, conditions and environment. A design problem is taken under consideration and designed from the scope of performative architecture. The design problem is the transformation of the Defence Line around Amsterdam, designing new buildings with the recent technologies as additions to the forts remaining from 1900’s. A “performative model”, which supports design from the conceptual stage until production of scale prototypes is structured by the author for this specific design problem. This performative model is used as a case study for the research of the role of the computational design tools in the design process and product of performative architecture. In addition to the design process, the role of using computer-aided manufacturing to increase performativity is envisioned and the proceeds of it to the relationship of design and manufacturing are also researched.

European railways have faced fundamental reforms to their organizational structures in the past decades. The reform plans, instigated by the European Union, resulted in a vast arrange of organizational structures visible today, more or less unique per EU member state. The main question that arises: do performances of European railways relate to the type of organizational structure in place? Did the EU reform plans indeed increase efficiency and effectiveness in Europe’s railway sectors? Israel’s railways possess a much shorter history than its European counterparts. The current organizational structure of Israel Railways presents a number of issues in adequately managing infrastructure and transport operations. Israel is interested to learn from experiences in European railway sectors if a renewed organizational structure might increase overall performance. The thesis work closely examines organizational structures and evaluates performances of railway sectors in 27 European countries. It investigates if a correlation between organizational structure and performance is visible at all and which lessons of the European reform plans can be taken along in designing optional new structures for Israel Railways.

Occupants and housing managers deal with several environmental problems in dwellings. To support the diagnosis of cause and effect and to promote good communication about health hazards, indicators of the relationship between physical properties, occupancy patterns and health risks are needed. The research project focussed on the selection of indicators that mark the relationships between physical parameters, user behaviour and health risk. Houses were inspected and occupants interviewed to study environmental conditions. Through modelling the relevance of parameters was evaluated. Performance evaluation in practice suggested the importance of communication and action oriented strategies. A tool was designed, used and evaluated after one year. The results ask for accessible information to support the assessment of performance and a simple action list to remediate major problems.

Nowadays, wireless networks are used in most of the applications with radio technologies being used in all kinds of wireless networks. In all wireless links, the transmitted packets can be lost. How to identify the quality of a certain wireless link and achieve the best delivery performance over a certain wireless network is an open issue. In this thesis, the performance of wireless mesh network, wireless sensor network and cellular network have been investigated by the method of measurements, simulations and mathematical model. Several novel algorithms also have been proposed. We have proposed two mechanisms to estimate wireless links where better performance is achieved compared to the traditional algorithms. The achievements lead to a higher end-to-end throughput (faster information delivery) for the IEEE 802.11 networks. Meanwhile, an energy saving and interference reducing mechanism for wireless mesh and sensor networks has been proposed and validated which can dramatically save energy in those wireless networks. Impact of wireless link quality on heterogeneous cellular and ad hoc networks has been evaluated and the results could be used for Telecom operators for the cellular networks optimization. Test-beds for IEEE 802.11 and IEEE 802.15.4 have been built and the 3G cellular networks have been studied via simulations. We looked at the the impact of the wireless link quality to the MAC layer for the IEEE 802.11 and IEEE 802.15.4; the impact of the wireless link quality to the IEEE 802.11 network layer. To understand the link quality characteristics of these two radios, we carried out many measurement experiments with various indoor and outdoor scenarios. The measurement methods and results are presented in Chapter 2. To achieve accurate link quality estimation, we proposed two estimation methods for different scenarios in Chapter 3. In Chapter 4, we used accurate link quality information to determine the packet transmission power level in the IEEE 802.11 and IEEE 802.15.4's MAC layer and the measurement results show that the energy consumption and interference reduces. The accurate link quality estimation methods are further used in data rate adaptation in the IEEE 802.11's MAC layer (Chapter 5) and route selection in the IEEE 802.11's network layer (Chapter 6). The measurements using IEEE 802.11 devices show tremendous performance enhancement. Our algorithms and results can be useful for all kinds of protocol designs for IEEE 802.11 and IEEE 802.15.4 networks. Furthermore, we look at the end-to-end performance of the cellular multihop network which comprises of two different wireless networks, 3G UMTS/HSDPA network and IEEE 802.11 network in Chapter 7. When multiple TCP flows exist in the cellular multi-hop network, different flows may not share the cellular network's resources fairly due to the fact that each flow may have different topology and wireless link quality. We have proposed a weighted scheduling method which obviously alleviates this unfairness. In Chapter 8, a typical video streaming traffic, MPEG-4 is used to evaluate the end-to-end performance over the cellular multi-hop network. The results show that wireless link quality also has great impact on the end-to-end performance of MPEG-4 over the cellular multi-hop network. Our result can be used by the telecom operators to optimize the UMTS/HSDPA system for the cellular multi-hop scenario. We conclude our thesis and suggest the future research directions in Chapter 9.

Peer-to-Peer systems are nowadays a very popular solution for multimedia distribution, as they provide significant cost benefits compared with traditional server-client distribution. Additionally, the distribution of scalable content enables the consumption of the content in a quality suited for the available bandwidth and the capabilities of the end-user devices. Thus, the distribution of scalable content over Peerto- Peer network is a very actual research topic. This paper presents a framework for the distribution of scalable content in a fully distributed Peer-to-Peer network. The architectural description includes how the scalable layers of the content are mapped to the pieces distributed in the Peer-to-Peer system and detailed descriptions of the producer- and consumer-site architecture of the system. Additionally, an evaluation of the system’s performance in different scenarios is provided. The test series in the evaluation section assess the performance of our layered piece-picking core and provide a comparison of the performance of our system’s multi layer and single layer implementations. The presented system is to our knowledge the first open-source Peer-to-Peer network with full Scalable Video Coding support.

With the increasing adoption of distributed systems in both academia and industry, and with the increasing computational and storage requirements of distributed applications, users inevitably demand more from these systems. Moreover, users also depend on these systems for latency and throughput sensitive applications, such as interactive perception applications and MapReduce applications, which make the performance of these systems even more important. Therefore, for the users it is very important that distributed systems provide consistent performance, that is, the system provides a similar level of performance at all times. In this thesis we address the problem of understanding and improving the performance consistency of state-of-the-art distributed computing systems. Towards this end, we take an empirical approach and we investigate various resource management, scheduling, and statistical modeling techniques with real system experiments in diverse distributed systems, such as clusters, multi-cluster grids, and clouds, using various types of workloads, such as Bags-of-tasks (BoTs), interactive perception applications, and scientific workloads. In addition, as failures are known to be an important source of significant performance inconsistency, we also provide fundamental insights into the characteristics of failures in distributed systems, which is required to design systems that can mitigate the impact of failures on performance consistency.

The study of the history of computing infrastructures reveals an integration trend. For example, the explosive growth of the Internet in the 1990s was the result of an integration process started in the 1960s with the emerging networks of computers. By using the Internet, millions of users were capable of accessing information anytime and anywhere, much like other daily utilities such as water, electricity, and telephone. However, an important category of users remained under-served: the users with large computational and storage requirements, e.g., the scientists, the companies that focus on data analysis, and the governmental departments that manage the interaction between the state and the population (such as census, tax, and public health). Thus, in the mid-1990s, the vision of the (Computing) Grid as a universal computing utility was formulated. The main benefits promised by the Grid are similar to those of other integration efforts: extended and optimized service of the integrated network, and significant reductions of maintenance and operation costs through sharing and better scheduling. While the universal Grid has yet to be developed, large-scale distributed computing infrastructures that provide their users with seamless and secure access to computing resources, individually called Grid parts or simply grids, have been built throughout the world---in different countries, for different sciences, and both for production work and for computer-science research. At the same time, the main technological alternatives to grids, that is, supercomputers and large clusters, have evolved into much larger, scalable, and reliable systems. Thus, the integration of existing grids into larger infrastructures and finally into The Grid is key in keeping the grid vision attractive for its potential users. The integration of grids raises a double challenge, one related with the efficient scaling of a distributed computing system, the second associated with the operation of a system across different ownership and administrative domains. Thus, many of the traditional approaches for inter-operating computer systems, such as those based on completely centralized or purely decentralized system architectures, are eliminated from the start. To mark the distinction between the typical problem of integrating smaller components into a larger system and the double challenge of grid integration, we call the latter the problem of grid inter-operation. In this thesis we approach the problem of grid inter-operation with two main objectives: to design a comprehensive framework for the study of grid inter-operation mechanisms, and to provide an initial but good solution for this problem. We design a framework for the study of grid inter-operation that includes a toolbox for grid inter-operation research and a method for the study of grid inter-operation mechanisms. In the research toolbox we include the Grid Workloads Archive (GWA), a comprehensive model for grid resources and workloads, the GrenchMark performance evaluation framework, and the Delft Grid Simulation (DGSim) framework for repeated and realistic simulations of multi-cluster and multi-grid environments. The GWA and our comprehensive model show that grid computing is mostly used in practice for single-processor jobs and not for parallel computing, which raises previously ignored challenges related to the volume of jobs to be managed. We also devise in this thesis a method for studying grid inter-operation mechanisms. We answer using our framework important questions regarding existing grid operation mechanisms, and in particular show that these mechanisms are too limited to cope with real and realistic conditions. We further demonstrate the usefulness of our framework by designing Delegated MatchMaking, a novel mechanism for inter-operating grids. This mechanism is used to operate an architecture that is a hybrid between hierarchical and purely decentralized architectures. The Delegated Matchmaking mechanism attempts to use the local resources of a grid as much as possible and also transparently extends the local environment with resources obtained (delegated) from other sites when resources are not available locally. Our approach is compared with five alternatives through trace-based simulations, and is found to deliver the best performance, especially when the system is heavily loaded. While many other mechanisms can be designed in the future, our experiments prove that the Delegated MatchMaking approach already is a good solution for the problem of grid inter-operation. Our experiments also demonstrate that having grids inter-operate leads to better performance than having the same grids operate independently.

Recent trends show a steady increase in the utilization of heterogeneous multicore architectures in order to address the ever-growing need for computing performance. These emerging architectures pose specific challenges with regard to their programmability. In addition, they require efficient application mapping schemes to fully harness their processing power and avoid bottlenecks. In this respect, it is of critical importance to analyse application behaviour, and the data communication between tasks, in particular. In this dissertation, we present a profiling framework that helps developers to gain an insight into the behaviour of an application. The presented profiling framework is generic and not restricted to a particular platform, application, or purpose. We utilize this framework with the primary goal of mapping applications onto a heterogeneous multicore architecture. The framework includes a memory access profiling toolset, called QUAD, that provides quantitative information regarding the memory accesses in an application. QUAD utilizes Dynamic Binary Instrumentation (DBI) to detect the actual data dependencies that occur between the tasks of an application at runtime. Additionally, it also provides accurate memory access measurements, such as the amount of data transferred between tasks and the memory size required for their communication. Such information can be utilized to identify critical parts of an application, to highlight coarse-grained parallelism opportunities, and to guide code optimizations. As a proof of concept to substantiate the usefulness of the extracted profiling information, we utilize the main output of QUAD, the Quantitative Data Usage (QDU) graph, as the input model to formulate a general application partitioning problem. The formulation of this intractable problem is flexible and accommodates different design objectives and constraints. Subsequently, we propose a heuristic algorithm to find high quality partitions of an application in a reasonable amount of time. In addition to the complexity analysis of the proposed algorithm, we present a thorough theoretical analysis of the application partitioning problem. In order to evaluate the quality of the solutions, we developed a test bench for generating synthetic QDU graphs and compared the results against the optimal partitions obtained using an exhaustive search. The comparison results show that the proposed heuristic algorithm is able to provide optimal or near-optimal solutions. To further prove the applicability of the profiling framework, we investigate in detail the utilization of the framework in practice, by mapping two real applications onto a heterogeneous reconfigurable architecture. To achieve this goal, we propose a hardware/software partitioning methodology that introduces the concept of merging tightly-coupled tasks based on the data communication analysis. Moreover, the profiling information is utilized to fine-tune the applications and optimize their data flow. The obtained results show a performance increase of 192% and 30%.

This document reports the progress of Delft Cluster project CT04.30 "Safety against flooding" till June 2009. Fundamental knowledge from the project has resulted in a large number of scientific publications, PhD theses and MSc theses. Work package A 1 in particular has resulted in high-profile scientific publications, immediately awarded with high scores on the citation index. Furthermore, the project has provided education and training as scientists and practising engineers to a large group of PhD and MSc students. Research knowledge from the project has been implemented in models, such as Delft3D, and has enhanced the expertise of staff of Delft Cluster institutes. For instance, Jos Dijkman has been appointed, as the only foreigner, in an American review commission under the National Academy of Engineering and the National Research Council, charged with the review of all post-Katrina studies by the Interagency Performance Evaluation Taskforce. Applied knowledge from the project has been used and disseminated in various ways. Optical glass fibre cables from work package A 1 provided the spinoff of a method to monitor groundwater upwelling at the toe of inner dike slopes. Consultancies (DHV, HKV) now routinely apply morphological models of work package A2 to P KB Room for the River measures. Work package A3 has established the probability of occurrence of super storm surges with greater accuracy by reconstructing storm-surge levels from the last 10,000 years using novel deposit dating methods. Findings from work package B are to be incorporated in guidelines for flood defence design and evaluation, thus affecting the evaluations for the "Hydraulische Randvoorwaarden". The system behaviour identified and analyzed in work package C turns out to be so important for the overall safety of dike rings, that it will inevitably lead to the need of adopting a new safety philosophy on a short term. Knowledge from work package A 1 has been implemented in the hydrology curriculum of Delft University of Technology. Knowledge from work package A2 has been included in the PAO course on Room for the River.