Design of multi-component periodic maintenance programs with single-component models

in IISE Transactions (2018)

Design of point fitted insulating glass units

Doctoral thesis (2015)

Today’s building façades are not imaginable without the building material glass. Modern architects capitalise the transparency and the load carrying capacity of glass elements in the design of filigree ... [more ▼]

Today’s building façades are not imaginable without the building material glass. Modern architects capitalise the transparency and the load carrying capacity of glass elements in the design of filigree and light-flooded structures. Priority is thereby given to the maximal transparency and the energy efficiency of the glass façade. In fact, the strategy paper “EU 2020” formulated by the European Union has an important impact on the design of glass façade and the energy efficiency will be a focal point in the design of glass façades in future. The optimal combination of transparency and energy efficiency is achieved by using point fitted insulation glass units. Their application in glass façades becomes therefore indispensable in the future. <br />Currently, three different point fitting systems for point fitted insulation glass units exist. They however present several disadvantages concerning their installation procedure and the tightness of the glazing cavity. Additionally, a general design concept for point fitted insulation glass does currently not exist. In consequence, point fitted insulation glass is a non-regulated construction product and requires an approval in individual cases from the national building authorities. <br />A model to proof the structural integrity of a developed point fitted insulation glass unit with a suitable point fitting system and edge seal system is proposed. A state of the art investigation reveals the Fischer undercut anchor to be the most suitable type for the application in insulation glass. A novel design concept for point fitted insulation glass with undercut anchors is developed. The concept considers the determination of the climate loads and proposes a verification procedure for each structural element of the insulation glass unit. For this purpose, an existing climate load model for linearly supported insulation glass is analytically extended to the static system of point fitted insulation glass units with undercut anchors. For the verification of the connection undercut anchor in glass, an existing design method for point fitted single and laminated glazing is extended to point fitted insulation glass. Component tests are conducted on the Fischer anchor and its ultimate load bearing capacity in glass is determined. A calibrated numerical model of the proposed point fitted insulation glass unit with the Fischer anchor is developed for parametric studies. Large scale tests on the proposed new point fitted insulation glass unit are run with the aim to verify the numerical model, the climate load model and the extended design method and to proof the structural integrity of the entire unit. Finally a new point fitted insulation glass unit with a suitable point fitting type and a corresponding novel design concept is developed. [less ▲]

Design of sheet pile installation by vibration

in Geotechnical and Geological Engineering (2004), 22(3), 391-400

In the Netherlands 70% of the steel sheet piles are installed with vibrators. This is because vibrators have a high production rate and therefore a low installation cost. This method only works for soft ... [more ▼]

In the Netherlands 70% of the steel sheet piles are installed with vibrators. This is because vibrators have a high production rate and therefore a low installation cost. This method only works for soft peat and clay layers and saturated sand layers which are not densely compacted. During pile installation several problems might occur. In this paper the attention is paid to avoiding jamming of the pile before it has reached its planned depth. In most of these cases this is caused by a design error which has let to a vibrator which is too light. Over the years different design tools, such as computer models, design graphs and design equations, have been developed in order to predict the minimum required vibrator force. In this paper a new design equation is presented, which consists of three parts: the mass of the sheet pile, the friction along the shaft and the soil resistance at the tip of the pile based on the cone penetration resistance. This equation and several other design tools for sheet pile installation, have been compared with 18 field tests. It was found that the general design graphs of the Dutch Union of Foundation Contractors (NVAF), the design equation of the Dutch Civil Engineering Centre for Construction Research and Design Rules (CUR) and the German design equation of the EAU1996 gave very poor results. The computer model Vibdrive from Holeyman (1996), the design graphs for specific locations from the NVAF and the new presented design equation from the author gave reasonable predictions. Since the computer program is, because of its complexity, not regarded as a design tool for daily design work and the local design graphs only exist for a small number of locations in The Netherlands, the new design equation is according to the field tests the best method for the calculation of the vibrator needed for sheet pile installation. [less ▲]

Design of single-span beams for SLS and ULS using semi-continuous beam-to-column joints. Part 2: Composite beams with variable bending stiffness and joints according to EN 1993-1-8

in Steel Construction (2017), 10(2),

The objective of this article is to facilitate the use of semi-continuous joints by providing ready-to-use tables and charts for design, which also permit the benefits accruing from the use of semi ... [more ▼]

The objective of this article is to facilitate the use of semi-continuous joints by providing ready-to-use tables and charts for design, which also permit the benefits accruing from the use of semi-continuous composite beams to be directly identified. The relevant features for the design of composite beams, such as bending moment distribution, maximum deflection and natural frequency, are derived analytically. The influence of semi-continuous steel joints on the performance of single-span composite beams is analysed. The article concludes with an example of the use of a new slim-floor beam type – the composite slim-floor beam (CoSFB). The tables and charts derived are applied in this example with the intention of demonstrating the advantages of using semi-continuous joints in combination with composite beams. The present article extends the design of semi-continuous steel beams presented in the previous article on this subject. [less ▲]

Design Optimization for Low-Complexity FPGA Implementation of Symbol-Level Multiuser Precoding

in IEEE Access (2021), 9

This paper proposes and validates a low-complexity FPGA design for symbol-level precoding (SLP) in multiuser multiple-input single-output (MISO) downlink communication systems. In the optimal case, the ... [more ▼]

This paper proposes and validates a low-complexity FPGA design for symbol-level precoding (SLP) in multiuser multiple-input single-output (MISO) downlink communication systems. In the optimal case, the symbol-level precoded transmit signal is obtained as the solution to an optimization problem tailored for a given set of users’ data symbols. This symbol-by-symbol design, however, imposes excessive computational complexity on the system. To alleviate this issue, we aim to reduce the per-symbol complexity of the SLP scheme by developing an approximate yet computationally-efficient closed-form solution. The proposed solution allows us to achieve a high symbol throughput in real-time implementations. To develop the FPGA design, we express the proposed solution in an algorithmic way and translate it to hardware description language (HDL). We then optimize the processing to accelerate the performance and generate the corresponding intellectual property (IP) core. We provide the synthesis report for the generated IP core, including performance and resource utilization estimates and interface descriptions. To validate our design, we simulate an uncoded transmission over a downlink multiuser channel using the LabVIEW software, where the SLP IP core is implemented as a clock-driven logic (CDL) unit. Our simulation results show that a throughput of 100 Mega symbols per second per user can be achieved via the proposed SLP design. We further use the MATLAB software to produce numerical results for the conventional zero-forcing (ZF) and the optimal SLP techniques as benchmarks for comparison. Thereby, it is shown that the proposed FPGA implementation of SLP offers an improvement of up to 50 percent in power efficiency compared to the ZF precoding. Remarkably, it enjoys the same per-symbol complexity order as that of the ZF technique. We also evaluate the loss of the real-time SLP design, introduced by the algebraic approximations and arithmetic inaccuracies, with respect to the optimal scheme. [less ▲]

Design principles of nuclear receptor signaling: how complex networking improves signal transduction.

in Molecular Systems Biology (2010), 6

The topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of 'design' aspects of the topology of these networks that ... [more ▼]

The topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of 'design' aspects of the topology of these networks that might appear unnecessarily complex or even functionally paradoxical. In realistic kinetic models of increasing complexity, calculations show how these features correspond to potentially important design principles, e.g.: (i) cytosolic 'nuclear' receptor may shuttle signal molecules to the nucleus, (ii) the active export of NRs may ensure that there is sufficient receptor protein to capture ligand at the cytoplasmic membrane, (iii) a three conveyor belts design dissipating GTP-free energy, greatly aids response, (iv) the active export of importins may prevent sequestration of NRs by importins in the nucleus and (v) the unspecific nature of the nuclear pore may ensure signal-flux robustness. In addition, the models developed are suitable for implementation in specific cases of NR-mediated signaling, to predict individual receptor functions and differential sensitivity toward physiological and pharmacological ligands. [less ▲]

Design principles study of ROS management and ROS-induced mitophagy with a kinetic model

Poster (2013, September 27)

In vivo evidence demonstrates three fundamental interconnected adaptive survival mechanisms , which protect against excessive ROS that is generated during mitochondrial dysfunction: (i) autophagy ... [more ▼]

In vivo evidence demonstrates three fundamental interconnected adaptive survival mechanisms , which protect against excessive ROS that is generated during mitochondrial dysfunction: (i) autophagy/mitophagy, (ii) adaptive antioxidant response and (iii) NFkB signaling in cancer and neurodegeneration. We have been expanding a kinetic model which recapitulates the consensus understanding of the mechanisms responsible for cellular ROS – management system and performed modular analysis to analyze emergent behavior. We started with the simplest model and added stepwise new modules. We identify the qualitative role (certain emergent behavior) attributed to each module and thus understand the design principles of the system. We propose a detailed, mechanistic, kinetic model for studying how mutations relevant for diseases such as PD and cancer affect the emergent behavior of ROS management network. [less ▲]

Design process ingredients: a comparison between group and individual work

in Cross, N.; Christiaans, H.; Dorst, K. (Eds.) Analysing Design Activity (1994)

In this paper a comparison is made between the design processes of an individually working designer and of a group of designers based on protocol analysis. The analysis focused on the differences and ... [more ▼]

In this paper a comparison is made between the design processes of an individually working designer and of a group of designers based on protocol analysis. The analysis focused on the differences and similarities in the ingredients of the two processes. The basic ingredients used for the analysis were: Issues, Arguments, Alternatives, Criteria, Decisions, External information, and Others. Comparisons have been made between: the group as a whole and the individual designer; the individual group members; the individual group members and the individual designer. The results provide a first step towards a better understanding of the differences between group and individual work. The paper also discusses some of the limitations of this type of study. [less ▲]

Design rules for slim-floor girders considering the composite behaviour

in Mäkinen, Jari (Ed.) The 13th Nordic Steel Conference (NSCC-2015) (2015, September 23)

Due to the demand for sustainable buildings and slim constructions, composite slim-floor systems become more important. The present European Codes do not include complete design rules for shallow-floor ... [more ▼]

Due to the demand for sustainable buildings and slim constructions, composite slim-floor systems become more important. The present European Codes do not include complete design rules for shallow-floor beams. Therefore, the objective of the recent research work was concentrated on the development of additional regulations, considering ultimate limit state, serviceability limit state and fire design. Apart from traditional sections consisting [less ▲]

A design strategy for phase synchronization in Precoding-enabled DVB-S2X user terminals

Scientific Conference (2021, June)

This paper address the design of a phase tracking block for the DVB-S2X user terminals in a satellite precoding system. The spectral characteristics of the phase noise introduced by the oscillator, the ... [more ▼]

This paper address the design of a phase tracking block for the DVB-S2X user terminals in a satellite precoding system. The spectral characteristics of the phase noise introduced by the oscillator, the channel, and the thermal noise at the receiver are taken into account. Using the expected phase noise mask, the optimal parameters for a second-order PLL intended to track channel variations from the pilots are calculated. To validate the results a Simulink model was implemented considering the characteristics of the hardware prototype. The performance of the design was evaluated in terms of the accuracy and stability for the frame structure of superframe Format 2, as described in Annex E of DVB-S2X. [less ▲]