Groendus – Optimal EV charge management
Who are we? Groendus helps businesses optimize their energy management and make it more sustainable – by saving energy, generating energy themselves, and consuming energy intelligently. We look far beyond the electricity meter. But for the energy transition to succeed, we need to do more. That’s why we’re also building a future-proof energy system. TogetherView problem details
Groendus – Optimal EV charge management
Who are we? Groendus helps businesses optimize their energy management and make it more sustainable – by saving energy, generating energy themselves, and consuming energy intelligently. We look far beyond the electricity meter. But for the energy transition to succeed, we need to do more. That’s why we’re also building a future-proof energy system. TogetherView problem details
KLM – estimating the booking curve
Introduction The Pricing & Revenue Management team of Air France – KLM forecasts demand, willingness to pay, show-up rates, and booking curves of passengers. Based on that, we determine the optimal price to ask for airline tickets. The booking window of a flight (which starts one year before departure) is split up into 30 timeView problem details
KLM – estimating the booking curve
Introduction The Pricing & Revenue Management team of Air France – KLM forecasts demand, willingness to pay, show-up rates, and booking curves of passengers. Based on that, we determine the optimal price to ask for airline tickets. The booking window of a flight (which starts one year before departure) is split up into 30 timeView problem details
VSL – Time averages and their totals in the billing of natural gas
The fiscal metering of natural gas is often performed using a flow meter and a gas chromatograph. The flow meter is used to measure the volume flow rate of the gas passing the metering station. The gas chromatograph is used to measure the composition, from which the calorific value is determined. Both are measured atView problem details
VSL – Time averages and their totals in the billing of natural gas
The fiscal metering of natural gas is often performed using a flow meter and a gas chromatograph. The flow meter is used to measure the volume flow rate of the gas passing the metering station. The gas chromatograph is used to measure the composition, from which the calorific value is determined. Both are measured atView problem details
Doing the Math – Design of multi-commodity energy networks
Introduction Navigating the evolving energy landscape necessitates the imperative planning and design of multi-commodity energy networks, driven by various crucial considerations. The motivation for embracing multi-energy systems lies in unlocking efficiency benefits through coordinated efforts, with non-electric energy carriers like hydrogen offering superior long-term storage options and playing a vital role in decarbonization efforts. DespiteView problem details
Doing the Math – Design of multi-commodity energy networks
Introduction Navigating the evolving energy landscape necessitates the imperative planning and design of multi-commodity energy networks, driven by various crucial considerations. The motivation for embracing multi-energy systems lies in unlocking efficiency benefits through coordinated efforts, with non-electric energy carriers like hydrogen offering superior long-term storage options and playing a vital role in decarbonization efforts. DespiteView problem details
The Driving Force (TDF) – Optimal food production planning
BuyFresh The Driving Force (TDF) is the creator of the BuyFresh platform that helps small- to medium-scale food producers sell their products online. The production plan is one of the important day-to-day decisions that bakers make to optimize their profit. However, they often need more mathematical background to make an optimal production plan. To supportView problem details
The Driving Force (TDF) – Optimal food production planning
BuyFresh The Driving Force (TDF) is the creator of the BuyFresh platform that helps small- to medium-scale food producers sell their products online. The production plan is one of the important day-to-day decisions that bakers make to optimize their profit. However, they often need more mathematical background to make an optimal production plan. To supportView problem details
IKEA – Smart allocation of online orders
IKEA produces and distributes home furniture in 31 countries from more than 482 stores worldwide, and it does so with a shared and inspiring vision: to create a better everyday life for many people. Therefore, IKEA continuously focuses on improving its services and becoming more accessible to many people. To meet their expectations, we areView problem details
IKEA – Smart allocation of online orders
IKEA produces and distributes home furniture in 31 countries from more than 482 stores worldwide, and it does so with a shared and inspiring vision: to create a better everyday life for many people. Therefore, IKEA continuously focuses on improving its services and becoming more accessible to many people. To meet their expectations, we areView problem details
A Novel Strategy Model Approach for Racing Solar Cars in the Bridgestone World Solar Challenge
Introduction Top Dutch Solar Racing is a student team from Groningen that aims to develop and test technologies in the field of sustainable car mobility. We do this by building a solar energy-powered electric vehicle. The goal is to contribute to the industry by using and validating new technologies to improve carbon emission-reduced mobility.View problem details
The Heat Transition – Mathematical Models and Optimization
DHM advises and is leading processes and projects in mobility, infrastructure, water and energy. Sustainability, climate, smart cities and digital innovation is our core business. We accelerate in results, communication, positive leadership and connecting teams and other stakeholders. We believe in a sustainable future wherein people can move freely and live carefree together. We investView problem details
Stereo 3D Cloud Motion from Tandem Satellites
Harmony The European Space Agency has recently selected the Harmony mission to be implemented as the 10th Earth Explorer mission . Earth Explorers are innovative research missions, aiming to advance our knowledge of the Earth System. One of the main scientific objectives of Harmony is to resolve physical processes in the marine atmospheric boundary layerView problem details
Frequency Domain Characteristics in Nonlinear Trimmer Dynamics
Philips Drachten is one of the Philips largest development and production centers in Europe. Here, we work together with more than 2000 people on Personal Health products, such as the newest shavers, Avent Mother & Childcare products, OneBlades, Ladyshaves and beard trimmers. At Philips we use dynamical models to simulate and analyze the dynamicView problem details
Data-driven Parameters Tuning for Predictive Performance Improvement of Wirebonder Multi-body Model
The ASMPT Centre of Competency, located in Beuningen, is responsible for identifying new high-tech innovation opportunities for the full global ASMPT product portfolio. The equipment portfolio of ASMPT covers the complete back-end section of the semiconductor equipment market, and offers comprehensive assembly and advanced packaging solutions for its customers in the fields of optoelectronics, electronics,View problem details
Zoro Feigl – Glider
Introduction An artwork about control and letting-go: A dance of visible and invisible forces and the extreme powers that are needed to control the ephemeral. A high-tech child’s play flows through the space with heavy-duty industrial machinery. An industrial robot arm moves its limb elegantly high above the viewer. The gentle, but fiercely moving machineView problem details
Synopsys – Macro Legalization in Chip Design
Advanced silicon chips power the amazing software we rely on every day. They are the foundation for everything from smartphones and wearables to self-driving cars and machines that learn. Synopsys is a company for electronic design automation (EDA), i.e., we develop software that enables our customers (Intel, Samsung, Mercedes-Benz, and many more) to design andView problem details
Fontys – Smartscan
Fontys Hogescholen is a large (46,000 students, 5,000 employees) and broad public university of applied sciences with locations in ten cities in the south of the Netherlands (North Brabant and Limburg). The 25 separate Fontys institutes jointly provide more than 100 study programs – bachelor’s, master’s, associate degrees, and training and courses for the business market – and conduct practice-orientedView problem details
PostNL – Planning inter transports and loading trucks
Apart from mail delivery, PostNL’s most important service is to transport parcels ordered at web shops to consumers. This service is provided at an enormous speed and accuracy (99% within 24 hours) and at incredibly high volumes (> 106 parcels per day). As a consequence, highly efficient business processes are required to maintain this serviceView problem details
You2Yourself – Towards personalized health monitoring
You2Yourself (Y2Y) develops methods to measure biomarker profiles in periodic body fluid samples of individuals and algorithms to enable the early detection of life-threatening diseases in these profiles, which enhances the chance of cure. Next Generation Sequencing in blood and urine samples is used to establish personal baseline profiles at health. This enables sensitive detectionView problem details
VDL ETG – Droplet on Wafer
VDL Enabling Technologies Group is part of VDL Groep, an international industrial family-owned company with 97 subsidiaries, spread over 20 countries, and more than 17,000 employees. It is a conglomerate of flexible, independent companies, each with its own specialty. The strength of VDL Groep lies in the mutual cooperation between the companies. VDL Enabling TechnologiesView problem details
SWECO – Event Driven Model with an Objective to Control Traffic Lights
SWECO designs and develops societies and cities of the future. This consulting company advises in sustainable buildings, efficient infrastructure, and access to electricity and clean water. SWECO is the largest engineering and consultancy company in Europe, with over 15.000 employees. The Mobility Solutions team of SWECO actively works on optimizing traffic flows in today’s cities,View problem details
KNLTB – A Model for Optimal Rating in Tennis Matches
KNLTB KNLTB is the Royal Dutch Lawn Tennis Association. The main goal of KNLTB is to support as many people as possible – of all ages and (dis-)abilities – to play tennis and make sure they keep playing. We represent 560.000 tennis members associated with approximately 1650 local clubs. KNLTB coordinates the annual match calendar,View problem details
Vanderlande – Optimizing Warehouse Operations
Vanderlande is the global market leader for value-added logistic process automation at airports, and in the parcel market. The company is also a leading supplier of process automation solutions for warehouses. More than 45 million parcels are sorted by its systems every day, which have been installed for the world’s leading parcel companies. In addition,View problem details
ShoQR – Building a Mathematical Model to Estimate Joint Loading and Predict Joint Tissue Damage
We train physiotherapists in treating patients with knee osteoarthritis (degenerated, damaged cartilage). Overload of joints should be avoided, especially the repetitive impact on the affected leg, as this is related to cartilage degeneration. Three-dimensional motion analysis allows us to measure joint load with high precision but is very expensive. Together with physiotherapists and universities, weView problem details
PostNL – Model for Optimal Connection Between Customer and Sorting Center
Apart from mail delivery, PostNL’s most important service is to transport parcels ordered at webshops (PostNL’s customers) to consumers. This service is provided at an enormous speed and accuracy (99% within 24 hours) and at incredibly high volumes (parcels per day). As a consequence, highly efficient business processes are required to maintain this service inView problem details
KWR – Predicting the Removal Performance of Activated Carbon Filters in Water Treatment
In the Netherlands, about one-third of the drinking water is produced out of surface water that may contain all kinds of micropollutants (pesticides, pharmaceuticals, industrial compounds). A large fraction of these drinking water production sites uses filtration by sorption onto activated carbon as an important barrier for micropollutants that are present in the water. TheView problem details
Synopsys – Latency Prediction for On-chip Communication
When placing components on a chip one is faced with several objectives. A major objective is that the length of the connections between the components should be minimal. For this aspect heuristic algorithms are available. Another objective is that the envisioned clock frequency can be met, or at least have the smallest violation. This frequency isView problem details
MARIN – The Numerical Towing Tank
The Maritime Research Institute Netherlands (MARIN) has been expanding the boundaries of maritime understanding of hydrodynamic research for over eighty years. MARIN has a dual mission: to provide the industry with innovative design solutions and to carry out advanced research for the benefit of the entire maritime sector. Starting in the 1930s, one of ourView problem details
SWECO – Controlling Traffic in the City of the Future
SWECO designs and develops societies and cities of the future. This consulting company advises in sustainable buildings, efficient infrastructure, and access to electricity and clean water. SWECO is the largest engineering and consultancy company in Europe, with over 15,000 employees. The Mobility Solutions team of SWECO actively works on optimizing traffic flows in today’s cities,View problem details
Bruil – Prediction of Print Success for Concrete 3D Printing
Bruil Beton & mix is specialized in the production of concrete for all kinds of applications. In the past years, Bruil has developed a new, exciting technique that has revolutionized this sector: the production of prefab elements using concrete 3D printing. This development offers architects a completely new scale of design possibilities in form, color,View problem details
Hendrix Genetics – Turkey Body Weight Prediction
Hendrix Genetics is a Dutch multi-species animal breeding, genetics, and technology company and one of the world’s leading breeders and distributors of turkeys. An important characteristic of turkey breeding is body weight. In a recent trial, approximately 200 turkeys were walked individually through a corridor in which a force plate was placed. During each walk,View problem details
DNV GL – Stability Analysis of a Buck Converter in Feedback Control
DNV GL in brief DNV GL is a global quality assurance and risk management company. Driven by our purpose of safeguarding life, property, and the environment, we enable our customers to advance the safety and sustainability of their business. We provide classification, technical assurance, software, and independent expert advisory services to the maritime, oil &View problem details
Hobaho – Optimal Use of in Vitro Techniques in Dutch Bulb Industry
Introduction Dümmen Orange represents a legacy of floricultural excellence for more than a century in the making, providing the largest selection of superior flowers and plants on earth. Recently, Dümmen Orange acquired companies specialized in flowers from bulbs and tubers. The Dutch bulb industry distinguishes itself from the rest of the flower industry in thatView problem details
SciSports – Player Evaluation in Soccer Using 2D Tracking Data
Company Introduction SciSports is a spin-off from the University of Twente, founded by Giels Brouwer and Anatoliy Babic in 2012. SciSports is a company which focusses on applying Scientic Methods in the world of soccer. Currently our focus is on the application of data analytics in soccer. Currently we have offices in Enschede and Amersfoort,View problem details
CBS – Causal Effects of Government Decisions on Earthquakes in Groningen
CBS (Statistics Netherlands) is the national statistical agency of the Netherlands, responsible for all official statistics of and about the country. In recent years the activity of Statistics Netherlands has expanded to provide more in-depth technical analyses of all data that it collects and archives. The demand for such technical analyses has increased because allView problem details
CQM – Optimal Order Picking from a Large Retailer Warehouse
The situation is as follows: A conventional retail warehouse handles customer orders. A customer order is picked into different totes. The totes are picked by order pickers. For efficiency reasons, an order picker picks a set of totes. This set is called a batch. Products are stored in racks divided over multiple aisles. Ideally, aView problem details
SKF – Weibull Estimation of Bearing Performance from Acceptance Tests
SKF is the world-leading supplier of products and solutions in the rolling bearing business. Bearing performance is assessed via intensive life testing and physical modeling. Beyond that, customers may require specific acceptance tests in the specific operating conditions from their application. Acceptance tests are usually dealing with a limited sample size meant to surviveView problem details
MARIN – Quiescent Periods for Helicopter Landing on Ships
Helicopter landing operations on ships are dominated by the expectation that ship motions will stay inside operational limits for a given time. For naval ships, the main criterium is the touchdown conditions. The minimal duration of an operational window is expressed in tens of seconds. The assessment of this expectation is done by the landingView problem details
ABN Amro – The Fair Value of a Mortgage
ABN AMRO is a retail bank and mortgages are an important part of the core business model. The balance sheet covers over 150 billion euros in residential mortgages, which is about 40% of the total assets. In order to properly steer the balance sheet and manage the bank’s risks, it is essential to correctly estimateView problem details
TNO – Analyzing and Predicting Impact Created by Accidents on Road Networks
Road networks are becoming more and more vulnerable to incidents as a result of an increasing level of congestion. Predicting ‘reliably’ the expected time of arrival (ETA) is therefore becoming a serious challenge as incidents/accidents occurrence is quite a random process and their impact depends on a variety of factors making it far from trivialView problem details
Shell – Numerical-physical Modeling of Miscible Fluids in Pipeline Transport
In the oil and gas industry hydrocarbons are transported through long pipelines under various conditions. This transport process generally involves multiple chemical components present in multiple phases (oil, gas, water). The mathematical modeling and simulation of these problems is often done with one-dimensional models that treat the phases as immiscible. However, a particular case thatView problem details
Ericsson – Route Information from a Central Route Planner
We present a discussion of a problem posed by researchers of the company Ericsson, namely, to estimate the fraction of the road users in a road network that must participate in a central route planning scheme such that travel time predictions improve significantly. A road user who participates is expected to inform the central routeView problem details
Schlumberger – Displacement of a Viscoplastic Fluid in an Inclined Slot
The steady displacement of one viscoplastic fluid by another is studied in an inclined channel. The aim is a prediction of the finger width from simple balance laws. It is argued that no accurate prediction can be acquired from the far-field velocity profiles only, but that instead a calculation of the two-dimensional behavior near theView problem details
KPN Research – Cache as Ca$h Can
In this contribution, several caching strategies for the World Wide Web are studied. Special attention is paid to the so-called proxy placement, i.e. placing of caches on carefully selected nodes in the network near to the end-users. Using both a deterministic and a stochastic approach, algorithms are developed for calculating the allocation and sizes ofView problem details
NLR – Wind Tunnel Model Position and Orientation
In this contribution, the determination of the position of moving and deforming objects in wind tunnels from CCD camera information is studied. An analytical approach is discussed which solves the problem directly from manipulating nonlinear distance formulae. Also, a least-squares approach is given, which is most convenient to implement from a numerical point of view.
Trespa International – Modelling of moisture induced warp in panels containing wood fibres
In this contribution the deformation of panels, used a.o. in furniture, is discussed in relation to the moisture content. It is shown how the variations in temperature, water and resin concentrations during the pressing process of the panels can be modelled. The panel deformation is modelled using linear elasticity theory. An explicit analytical expression forView problem details
Philips NatLab – On Compact Models for High-voltage MOS Devices
Fast evaluation of integrated circuits(ICs) requires the availability of so-called compact models, i.e. simple-to-evaluate relations between the voltages and the currents in the IC-components. In this paper, the compact model for a particular IC-part, the LMDOS device, is studied. This model consists of coupled submodels, each of which describes a separate part of the LDMOSView problem details
Akzo Nobel – Color Matching
We consider the problem of creating paint of a certain target color by mixing colorants. Although a large number of colorants is available, in practice it is only allowed to use a limited number. We focus on the problem of selecting the right subset of colorants.
Oude Kerk Delft – The Bourdon Bell and the Skewed Tower
The first parish church of Delft, the old church, was built around 1200. In front of the church a 75 meters high tower, with a brickwork spire and four turrets, was built in 1350. Even during its construction, the tower was plagued by subsidence. This could be because the water in the Oude Delft hadView problem details
Demis – Zoning Problem in Determining Environmental Impacts of Traffic
Introduction Traffic has an impact on the environment. Traffic models are normally used to calculate the traffic intensities on the road network. The calculated traffic intensities form the basis for calculating environmental impacts. In the impact assessment, the traffic intensities are converted to the width of the zone that has negative impacts on the traffic.View problem details
X-flow – Leakage Detection Method
For the purification of water hollow fiber membranes are increasingly being used. These are porous reeds with a diameter of between 1 to 2 mm, made by a particular type of plastic. The ‘wall’ of these reeds has a fine porous structure that is permeable for water, but not for particles of certain sizes. TheView problem details
AOT – ADR Option Trading
Problem The problem AOT presents is that of ADR-option pricing. In the brief outline below the problem and its setting are described. In the final presentation of the problem, a brief introduction to options and option pricing will be given, such that the jargon will be clear. ADRs As a stock and derivative trading firm,View problem details
Rekenkamer – Is there a Financial Life After an Error?
In many cases, accountants make their judgment on a financial report based on samples taking at random. An approval is issued when the data in the report satisfies a given reliability interval (often reliability of 95% is used), i.e., the errors found in the samples is not exceeding a certain critical value. In reality, quiteView problem details
Twaron – The Rotor Spinning Process for Fibre Production
At Teijin Twaron in Arnhem new ways of producing fibres are being developed. One of the interesting new techniques is “The Rotor Spinning Process”. In principle, this process looks a lot like the making of sugar floss (or cotton candy) at the carnival/fair. Here, however, we deal with a polymer-filled disc with tiny holes. TheView problem details
NOZ – Reconstruction of Sea-surface Temperatures Using Fossil Marine Plankton
The predictive quality of climate models can be enhanced by incorporating information about temperatures from the past. A number of methods have been developed to determine the ancient temperatures of the upper ocean, and one of these is based on the use of deep-sea microfossils. For many millions of years, a large number of speciesView problem details
Phytocare – Parameters to Grow Roses
In agriculture, the key point is optimizing the production at limited costs. For decennia already, one has tried for the best and one cannot do without a computer anymore. In present-day greenhouses, the control of the inner climate is fully automated. The inner climate could be held constant, but for the optimization of the production,View problem details
Artis – Aquarium Problem
The Artis Zoo has a problem in its Aquarium and in the adjacent Zoological Museum. Situation Part of the Aquarium is a corridor that contains so-called mammoth tanks which measure 5 by 2.5 by 20 meters and are filled with water. Because of the tropical fish inside, the water should have a temperature of 24View problem details
Philips – Compression of Data
Philips Natlab is looking for new ways to compress audio-signals. Situation A new method for the digital representation of high-quality audio signals has been introduced as an alternative to the widely used 16-bit recording format used for CD signals. This new method [3] produces 1-bit samples at a rate that typically is 64 times higherView problem details
Magma – Design Automation: Component Placement on Chips
The ‘holey cheese’ problem One of the steps in the design process of chips is the positioning of every single component or ‘cell’ on the chip. The cells are mutually connected by wires. The wiring scheme is given, and in this phase of the design process, the positioning of the various cells must be determined.View problem details
Eurodiffusie – Diffusion of Euro Coins over Europe
From 1st January 2002, we have the unique possibility to follow the spread of national euro coins over the different European countries. We model and analyze this movement and estimate the time it will take before on average half the coins in our wallet will be foreign.
Akzo Nobel – Instability in the Spinning of Fibers
A well-known problem in the spinning of fibers by drawing a liquid through a spin hole is that when the speed is increased, there appears an instability in the sense that the cross-section of the filament is no longer independent of time. In fact, oscillations arise at a large speed of spinning. In 1969 MatovichView problem details
Dr Daniel den Hoed Kliniek – Pattern Recognition in CT Scans
When making a diagnosis using a CT scan one looks for spherical shapes amidst bones and lung tissue. Where the bones show a value of 1000 on the CT san and air and lung tissue are at 0, the spheres distinguish themselves at a value of around 150. For the automatic pattern recognition one canView problem details
Eldim – Laser Percussion Drilling
Laser materials processing is well accepted in the industry. Most important applications are cutting, welding and marking. Drilling is a niche application. Only 2% of the system sold is used for drilling. In the gas turbine manufacturing, laser percussion drilling is used to drill film cooling holes. The typical hole diameter is 0.5 to 1.0View problem details
KPN – ADSL Modems
The Transmission Control Protocol (TCP) is a well-used protocol to send information files over the Internet. The essence of this protocol is that the total quantity of information is divided into a number of smaller packages. Sending the data error-free is made possible by detecting the packages in which an error has occurred and resendingView problem details
NMi Van Swinden Laboratorium – The T-factor for a Non Gauss-distribution
For a small sample from a normal or Gauss-distribution, it has been derived by Student with which factor one has to multiply the standard deviation of the sample such that, with a certain probability, the center of the distribution is found in the interval on both sides of the average of the sample, with sizeView problem details
Trespa – Pressing of a Corner Profile
In the fabrication of office desks and plates for walls, Trespa presses thermally layers of paper impregnated with resin. During the heating process (up to 160 degrees at 90 bar) polymerisation of the resin occurs and densification takes place up to 70 per cent. In a related process for the fabrication of wood fibre platesView problem details
Philips – The Behaviour of a Droplet of Polymer Solution in an Ink-jet Printer
Light-emitting polymer displays are a new, interesting flat display principle. The active material in the display is a very thin semiconducting polymer layer of order 100 nanometer. To obtain these thin layers a small concentration of the polymer is dissolved in a suitable solvent. Different colours can be obtained with different polymers. To make aView problem details
Nederlands Forensisch Instituut – Probability Model for Marks and Prints
From the Nederlands Forensisch Instituut there are two related problems, one about so-called tool marks and the other about shoeprints. Toolmarks appear when at a burglary a tool (a screwdriver or crowbar) is being used to break a door or window open. This tool leaves a mark: in the doorpost for example a mark orView problem details
KLM – Performance Forecast of a Flight Schedule
In search of a quick method to forecast the quality of a flight schedule Situation KLM flies to over 150 destinations with 97 aircraft. Four times a year, a new flight schedule is developed. Though the operational feasibility is taken into account up to a certain degree during the development process, the aim at thatView problem details
Het Nationaal Beiaard Museum – Hanging a Carillon in a Broek-system
A carillon consists of approximately 20 up to 45 bells. These bells hang in an open lantern-tower (like the Munttoren in Amsterdam) or inside a tower under the roof. A carillon is played using a keyboard that is generally located one story below the bells. A wire connects each clapper to the keyboard. The oldestView problem details
RIVO – Problems Surrounding the Expanding Pacific Oyster in the Eastern Scheldt
History of oysters Flat oysters have been commercially cultured in the Eastern Scheldt Estuary (The Netherlands) since 1875. After the severe winter of 1962/1963, which caused high mortality, the stock was diminished. Searching for alternatives, Dutch oyster farmers introduced the Pacific oyster to the Eastern Scheldt in 1964. The Pacific oyster is native to Japan.View problem details
NMI – Weighing Schemes
For the calibration of weights with various nominal masses, metrology institutes use special weight sets. For instance, the decade from 1000 g to 100 g is ‘covered’ by six weights: 1000 g, 500 g, 2 x 200 g and 2 x 100 g. In order to be able to distinguish between weights with the sameView problem details
SIG – Partitioning a Call Graph
A company has a large software system that has become costly to maintain. What they need to do is break the system into smaller more manageable modules. Of course, this is a job for a trained expert. However, when the system is largely an automated suggestion for a partition into modules is useful. Given aView problem details
IFKB – Spatiotemporal Patterns in High-density Surface Electromyography
Being recorded at the skin, a surface electromyographic signal (sEMG) reflects the electrical activity of an underlying muscle (or group of muscles). Hence, sEMG offers a fairly simple, non-invasive way to assess the activation of superficial muscles. The signal is an integral measure summing action potentials of many motor units, i.e. groups of muscle fibersView problem details
NFI – Dealing with Selection Effects in Forensic Science
Many areas of forensic science deal with questions concerning the selection of evidence. If certain features are used to select a suspect from a large group of potential suspects, can you use the same features as evidence in a legal case against the suspect? If the answer is yes, is the evidential value the sameView problem details
KLM – Planning Drinking Water for Airplanes
Part of the planning of each KLM flight consists in determining the quantity of drinking water to take on board. Risking a water shortage is not an option, whereas a surplus will cost unnecessary extra fuel. However, reading off the level of the water tanks can not be done accurately: on most airplanes, the waterView problem details
AMC – Warming up Bodies after Invasive Surgery
Hypothermia is used in a number of invasive cardiosurgical procedures. In limited hypothermia, a routine procedure in open-heart surgery, the human body is cooled down to 32 degrees Celcius, whereas in deep hypothermia, which is used less frequently, body temperatures go down as far as 20 degrees. The actual cooling of the body is doneView problem details
Chess – Gossiping to Optimality
Analysis and optimization of message delivery in wireless sensor networks Chess is a company of about 160 employees, with locations in Haarlem and Best, that offers products, solutions and services in the field of electronics, IT-applications and embedded software. One of the projects of Chess has to do with ‘wireless sensor networks’. Suppose that aView problem details
NMI – Calibration of Pressure Measurement
In pressure measurement, the value of pressure is determined by dividing the force exerted on a piston by the effective area of the piston. The effective area of the piston may differ from the actual area because of irregularities at the piston edge and because of leakage through the thin cavity between the piston andView problem details
TWARON – Bullet-proof Math
Twaron is a strong fiber. Teijin Twaron is a split off from AKZO-Nobel and is now part of Teijin, a Japanese company. Teijin Twaron is responsible for developing the Twaron fiber and its applications. One of the applications of Twaron is in bullet-proof vests. Twaron is interested in finding the velocity at which only aView problem details
Nucletron – Radiological Needlework
Nucletron is a high-tech, international company, that specializes in equipment for medical diagnostics. Problem description To treat prostate cancer with radiological techniques, the prostate is perforated with a number of needles. Before the radiological treatment may start, the exact positions of these needles must be known. To detect these positions, an ultra-sound sensor is used.View problem details
DSM – Catching Gas with Droplets
At DSM one is interested in the development of packaging materials that are not or little permeable for certain gases. Think of the packaging of meat in a polymer sheet, that should keep the meat free from oxygen. The idea to realize this is to include in the sheet of packaging material droplets that absorbView problem details
ASML – Optimizing Software Release Policy
ASML is a company located in Veldhoven that builds machines for manufacturers of computer chips. The software of these machines ASML sells now consists of one large package, a so-called monolith. Their current policy is to release a new version of this entire monolith approximately every nine months. This monolithic approach has a few disadvantages.View problem details
Regge en Dinkel – Mathematical challenge waterboard
Mathematical challenge waterboard Regge en Dinkel The waterboard Regge en Dinkel is responsible for the watermanagement of 1300 km2 in the eastern part of the Netherlands. The expected climate change will affect the watersystem; more and heavier rainfall will result in increasing discharge en flooding. The waterboard has three strategies to deal with these problems:View problem details
UMC – Rapid Calculation of the Radiofrequency Field Pattern in MRI
Introduction The physical principle of MRI is based upon the application of a strong static magnetic field to the patient. This field forces the magnetic spin moment of hydrogen nuclei in the patients to precess around the external field with a particular frequency which scales proportionally with the magnetic field strength. Central in the imagingView problem details
AMC – Modeling a Heart Pump
In acute heart failure, the cardiologist or cardiothoracic surgeon may introduce a catheter-mounted pump into the left heart chamber. The left heart chamber is responsible for maintaining the circulation through the following organs: brains, muscles, intestines, kidneys etc. Therefore, acute heart failure, and specifically heart failure of the left chamber, results in so-called cardiogenic shockView problem details
KLM – Optimizing the Reserve Strategy of Cabin Crew
The cabin crew of KLM receives a new roster every week, which shows their assignment for the next several weeks. A typical flight assignment consists of several days of duty followed by a number of days off. Such a combination of duty time and free time is fixed for each type of flight and isView problem details
ING – Improving an Equity Option Pricing Model
Introduction Volatility, i.e., the uncertain fluctuations in the prices of financial assets such as stocks, is of paramount importance in financial markets theory and practice. Volatility characterizes the risk of an investment. Moreover, volatility is a major determinant of the price of a financial derivative. A financial derivative is a contract that derives its valueView problem details
Innogrow – Optimizing a Closed Greenhouse
Innogrow develops and sells a new type of greenhouse, called GeslotenKas®. By closing the windows of a greenhouse and providing it with an integrated climate and energy system, maximal control is obtained over the growth factors and energy use. The closed greenhouse also functions as an energy source. Excess heat is saved in seasonal energyView problem details
ASML – A Sampling Problem
ASML develops machines to perform the very critical lithographic step in the process of integrated circuit manufacturing. Lithography boils down to exposing a photo lacquer (resist) present on a silicon plaque (wafer) with ultraviolet light using a mask (glass plate called reticle with a chrome pattern, derived from the integrated circuit layout, on it). TheView problem details
Equalis – Equalizing the Cost of Health Insurance
In the Netherlands, health care expenses show major differences amongst regions. For instance, citizens of Heerlen had average health care costs of 2811 euro per insured, whereas this was only 1.633 euros in Urk (published by Vektis, a collaboration of health insurance companies). A possible explanation might be that citizens of Urk have a betterView problem details
Centraal Planbureau – Economic Optimal Water Safety
Economic optimal water safety in the Netherlands is since the flood disaster of 1953 an important topic in policy and research. CPB published in 1954 a (social) cost-benefit analysis (CBA) of a comprehensive plan to increase the water security of the Netherlands (Tinbergen, J., 1954, The economic balance of the Delta plan, annex to theView problem details
MARIN – Parametric Roll of Ships
Introduction ‘Parametric roll’ is a phenomenon that sometimes suddenly occurs to ships sailing in the head or following seas. Apparently, without any clear reason, the amplitude of the roll motion (i.e. the rotation about the longitudinal axis of the ship) increases within a couple of roll periods, from a few degrees to above 45 degrees.View problem details
KNMI – An Objective Method to Associate Local Weather Extremes
Local weather extremes, like heavy rainfall or extreme temperatures, are usually connected to characteristic circulation patterns in the atmosphere. The figure below illustrates this fact for daily mean temperatures in July and August as observed in De Bilt. For two periods with extremely high temperatures the atmospheric circulation deviation from the time-mean flow as characterizedView problem details
DSM – Stiffening While Drying
Introduction Nowadays waterborne coatings (WBC’s) are increasingly replacing traditional organic solvent-borne coatings (SBC’s) in many applications due to stricter legislation originating from an ever-growing environmental awareness in society. One of the few disadvantages of WBC’s is that they generally require longer drying times as compared to SBC’s. For that reason, the drying process of WBC’sView problem details
DHV – Water Pumping Optimization
Grimsby Region In the figure, the schematic representation of the Grimsby drinking water supply region is given. Characteristics are: The supply regions Smithville, Beamsville, and Grimsby are situated at different heights With the use of the water buffers and the water pumps drinking water is transported to the three supply regions. The Pumps can beView problem details
Albemarle – Mixing and Modelling: How Mathematics May Mix Molecules
Introduction Albemarle is a big chemical concern with about 3700 employees and many plants worldwide. It is a manufacturer of polymers and fine chemicals, including additives and intermediates used in agricultural and cleaning products, drilling compounds, etcetera. Since mixing of different chemical compounds is one of its core techniques, Albemarle Research in Amsterdam (former AkzoView problem details
Stork – Modeling Compressible Non-Newtonian Chicken Flow
Stork Food Systems Stork Food Systems is the supplier of processing systems for poultry and fresh meat. As a technology market leader, with more than 45 years of experience, process knowledge and proven track record worldwide, we support and equip food processors to create maximum process value now and in the future. Problem description InView problem details
Phytocare – Modeling and Optimization of Algae Growth
Problem description The runoff water from greenhouses contains fertilizers and must be cleaned before it can be returned to the groundwater system. A means of doing this is to introduce algae into the water. The algae eat up the fertilizer and clean the water. Subsequently, the algae may be removed and sold as feed, forView problem details
MARIN – Thruster Allocation for Dynamical Positioning
MARIN, the Maritime Research Institute Netherlands, has become a reliable, independent, and innovative service provider for the maritime sector and a contributor to the well being of society. MARIN has been expanding the boundaries of maritime understanding with hydrodynamic research for over 70 years. Today, this research is applied for the benefit of Concept Development,View problem details
KEMA – Optimal Distributed Power Generation Under Network-Load Constraints
Leading authority in energy consulting and testing & certification. A global, leading authority in energy consulting and testing & certification, active throughout the entire energy value-chain – in a world of increasing demand for energy, KEMA has a major role to play in ensuring the availability, reliability, sustainability, and profitability of energy and related productsView problem details
ESA – Position Estimating in Peer-to-Peer Networks
The European Space Agency (ESA) is an agency for cooperation among the European States in space research, technology, and space applications. One of the topics of ESA is Satellite Navigation, being responsible for the construction of the Galileo system and an augmentation-system for GPS. Satellite Navigation has many applications, including route guidance for cars, theView problem details
Statkraft – Strategic Bidding in a Primary Reserve Auction
In any electric system, the generation has to match the consumption at all times. In the European interconnected (UCTE) grid, this balance is maintained by Primary Reserve. The four German grid operators procure their demand of Primary Reserve by means of a monthly auction, which results are publicly accessible. Generation units that can participate inView problem details
NXP – Routing for Analog Chip Designs at NXP Semiconductors
The increasing demand for smaller, faster, and multi-functional electronic devices such as smartphones is one of the driving forces in the semiconductor industry. Combined with requirements on power usage, sustainability, and wireless functionality this is generating challenges in several domains. During the design of the layout, which is a representation of the chip in shapesView problem details
NFI – Statistical Modelling of Pre-Impact Velocities in Car Crashes
Causing a lethal vehicle accident as a driver is a serious offense. Especially if driving speed was excessive, imprisonment for a substantial time is likely. The Netherlands Forensic Institute is frequently asked to estimate driving speed based on accident scene data. Estimation is based on a physics model that simulates the crash itself and theView problem details
Marin – Analysis of a Model for Ship Maneuvering
Traditionally, the study of the hydromechanical behaviour of ships (and floating bodies in general) is divided into ship hydrostatics (without motions in calm water) and ship hydrodynamics (with motions in either calm water or in waves and/or current). The area of ship hydrodynamics can be roughly divided into powering/propulsion and calm water resistance, seakeeping (motionsView problem details
Deltares – Optimal Flood Control
We are interested in the most appropriate way of formulating optimum control problems for heterogeneous, partially controllable water resources systems. These systems often need implicit time-stepping schemas for avoiding restrictive stability criteria. This distinguishes them from most technical systems on which control is applied. We are interested in various methods to solve the optimal controlView problem details
Chess – Node Counting in Wireless Ad-hoc Networks
A defining characteristic of wireless ad hoc networks is their dynamic behavior. In practice, it is not uncommon to find that the topology of even a small network deployed in a controlled environment changes from one moment to the next, without apparent changes to the layout of the nodes. This behavior stems from the inherentView problem details
Thales – Optimization of the Lifetime of Sensor Networks
Sensor networks and networks of wearable communication systems (for example networks that support emergency workers in their efforts) have strong requirements for their energy consumption. Instead of only focusing on minimization of energy consumption of the individual nodes (which leads to locally optimal solutions) it is important to maximize the lifetime of the whole network.View problem details
TataSteel – Image Recognition of Shape Defects in Hot Steel Rolling
Tata Steel is the 2nd largest steel producer in Europe with major manufacturing sites in the UK, the Netherlands, Germany, France, and Belgium. The IJmuiden site in The Netherlands hosts a fully integrated production process in which coils of coated steel strips are produced out of raw materials such as iron ore and coal. HotView problem details
Philips – A New Ray-tracing Method for Non-imaging Optics
Introduction In illumination engineering, the transfer of light from the source to the target is computed to obtain photometric quantities like the luminous intensity, color point, and brightness. The technique that is commonly used is the Monte Carlo (MC) ray tracing method that traces randomly rays through an optical system containing components like lenses andView problem details
MARIN – Structural Integrity of Marine Structures
Operators of ships and offshore structures face the responsibility of maximizing the operational window while taking care of the safety onboard. Periodic inspections help the operator to assess if the structure is still in one piece and whether repairs are required. Continuous monitoring of the structure’s response as motions and stresses is increasingly used toView problem details
Endinet – Future Challenges in the Electricity Grid
Endinet is a network company that distributes electricity and gas to various customers in the province of North-Brabant of the Netherlands. Endinet owns the medium (10kV) and low voltage (230V) networks of Eindhoven and a part of Veldhoven and is responsible for the operation and maintenance of these networks. Most of the network operators inView problem details
Bartels – Building a Mountain in The Netherlands
God created the world and the Dutch created the Netherlands. This old and popular expression among Dutch people could get a completely new meaning. After the polders, dikes, and Delta works, the Dutch may have a new flagship: the Dutch mountain. The idea started as a column by journalist and former professional cyclist Thijs Zonneveld.View problem details
KNMI – Fog Detection from Camera Images
KNMI products and services rely heavily on observations. Besides increasing amounts of data from traditional sources (such as observation networks), the use of open data, crowd-sourced data and the Internet of Things (IoT) is rapidly emerging. To deploy these sources of data optimally, the KNMI DataLab has been established. Data‐driven innovations that arise from public‐privateView problem details
RWS – Effective Water Storage as Flood Protection
Effectief water bergen: De mogelijkheden van Rijnstrangen als retentiegebied voor bescherming tegen overstromingen. De Nederlandse dijken zijn gedimensioneerd op een bepaalde afvoer die (statistisch gezien) eens in de 1250 jaar voorkomt. Dat wil zeggen dat hogere afvoeren tot overstromingen kunnen leiden, maar dat lagere afvoeren veilig (dat wil zeggen zonder overstromingen) via de rivieren afgevoerdView problem details
Philips – The Random Disc Thrower Problem
Philips Research is a global organization that helps Philips introduce meaningful innovations that improve people’s lives. We provide technology options in the area of health and well-being for both developed and emerging markets. Positioned at the front-end of the innovation process, we work on everything from spotting trends and ideation to proof of concept andView problem details
TNO – Stress Fields Inside of a Neck for more Accurate Crash Analysis
Background As a material (typically, a metal) is stretched, it can reach a point where all of the strain (deformation) is concentrated in just one area. For example, notice in the figure below how the material has become very narrow across a short length in the specimen which was initially cylindrical. This condition is calledView problem details
Fytagoras – Oxygen Transport in Germinating Seeds
Seed germination in most seeds depends on the availability of oxygen. Living seeds start respiration upon imbibitions and respiration accelerates at the moment the germination really commences. The availability of oxygen to the embryo in the seed depends on the oxygen concentration around the seed, the respiration rate of the cells (in the embryo), andView problem details
Heineken – Estimates on Returnable Packaging Material
Heineken Global Logistics is our international supply chain knowledge center, located in Zoeterwoude, the Netherlands. The Corporate Distribution & Logistics Department (CDL) delivers a significant contribution to the development of the Heineken business worldwide through business improvement projects, knowledge development initiatives, and policymaking in the area of distribution & logistics. One of the knowledge areasView problem details
NedCoffee – Coffee Market Volatility
Coffee is a tropical product, produced in over 50 developing countries. It makes an important contribution to socio-economic development and poverty alleviation and is of exceptional importance to exporting countries, some of which rely on coffee for over half their export earnings. For the 25 million smallholder farmers and their families who produce 80% ofView problem details
NS – Energy-efficient Railway Timetabling
Environmental and economic considerations urge companies to seek better, more efficient ways of using available resources. Energy is one of these resources, and railway systems are large consumers of electricity, indeed. Even the slightest improvement in the energy consumption of trains can lead to very visible effects, helping to reduce CO2 emissions and to improveView problem details
INCAS3 – Nonlinear Cochlear Mechanics
It is perhaps astonishing that in spite of the advances in medical imaging and other research techniques, the possibilities of visualizing damage to the human hearing system are very limited. Although there is a vast range of audiological tests that measure the effect of damage, pinpointing what is causing these effects is often impossible. This,View problem details
Witteveen+Bos – Monitoring the Sewer System
The old city centre of Delft is sensitive to both pluvial and fluvial flooding, especially specific areas in the eastern part of the city centre. This includes surcharging of sewers and flooding of streets and buildings due to storm events, overflowing of canals and high groundwater levels. In order to reduce flooding impacts, the canalsView problem details
WLN – A Statistical Tool for Water Quality Monitoring
For 30 years WLN safeguards the quality of drinking water in Groningen and Drenthe. By using chemical, biological and technological research protects the quality of the drinking water that water company Groningen and water transportation company Drente provide. Quality control is essential for WLN. Background Measuring the quality of drinking water is WLN’s core business.View problem details
HZPC – The Mathematics of French Fries
HZPC is the world-leading developer and seller of high-quality seed potatoes. It is a Dutch company with offices in Metslawier and Joure that operates internationally and that employs over 230 people. To serve its customers better, it also performs research in the growth and processing of its potato varieties. This project is related to theView problem details
CBS – Calculating Traffic based on Road Sensor Data
The Nationale Databank Wegverkeergegevens (NDW), a database for traffic data, contains the counts of more than 14,000 traffic loops, that are to be found in the Dutch system of motorways and provincial roads. During a day it is analysed how many vehicles of which type pass through these loops each minute. Each day this givesView problem details
Marel Stork – Chilling on the Chicken Express
System information In a processing line products hang, on a constant pitch, in a shackle, the shackle is attached to a chain by means of a trolley, on the other side the trolley has wheels that run of a profile. The assembly is called the overhead conveyor. The endless chain is running the whole productionView problem details
Ortec Finance – Forecasting Financial Scenarios using Expert Opinions
1 About Ortec Finance Ortec Finance is a company of about 200 employees and its two main offices are located in Rotterdam and Amsterdam. The central mission of Ortec Finance is improving financial decision-making and monitoring by providing understanding, transparency and control through a combination of market knowledge, mathematical models, and Information Technology (IT). PensionView problem details
HZPC – Predicting Early Bulking in Potatoes
Tuber bulking is the 4th growth stage in the development of potato. Tuber cells expand with the accumulation of water, nutrients, and carbohydrates. Tubers become the dominant site for the deposition of carbohydrates and mobile inorganic nutrients. In breeding we are looking for early bulking varieties (to be able to harvest most kg in desirableView problem details
Dümmen Orange – Optimal Cutting Strategies for Flowers
Dümmen Orange is a leading company in the breeding and development of cut flowers, potted plants, bedding plants, and perennials with over a century of experience in the horticultural industry. In addition to a large marketing and sales network, Dümmen Orange has a strong network of production locations. In these production centra, so-called mother plantsView problem details
MARIN – System Parameter Identification in Numerical Simulations
A common problem in numerical simulations is finding the correct parameter values of a mathematical model. A typical example from MARIN practice is the simulation of a ship manoeuvre, like a zig-zag or a turning circle (Figure 1), where the result is compared with the outcome of an experiment. The forces acting on the shipView problem details
NMGroup – Power Line Route Optimisation in a Finite Spatial Grid
Building new infrastructure such as transmission lines, roads, rail, etc. is always a source of controversy. High voltage transmission lines blight the landscape they are constructed on, bringing social, environmental, and economic detriment to the areas they run through, equally they form the fabric of modern infrastructure enabling efficient transfer of power across the country.View problem details
NKI – Accurate Dose Delivery for Radiation Therapy: Adapting Treatment to Daily Anatomy
For radiation oncology, we treat patients with head and neck tumours over the course of 6-7 weeks. This treatment is usually based on one CT scan prior to treatment. We use that as an input for dose calculations in the patient based on a collapsed cone superposition algorithm. To optimise the dose distribution we useView problem details
Mobidot – Mobility Profiling from Smartphone Sensor Data: Confidently Know How People Travel
Our SWI problem formulation focuses on advancing the quality of our data derivation. Mobidot infers the route, role, objective, and mode of transportation from Smartphone data. Smartphones possess a variety of sensors, including GPS, mobile telephone (4G) and wi-fi signals, accelerometer-based mode, etc. that can be used to determine the motion and position of theView problem details
KNMI – Synchronizing Numerical Models of the Atmosphere to Improve Weather and Climate Predictions
Systems as diverse as clocks, singing crickets, cardiac pacemakers, firing neurons and applauding audiences exhibit a tendency to operate in synchrony. The phenomenon that dynamical systems synchronise their behaviour by some form of information exchange is known as synchronisation. In recent years, the concept of synchronisation is being applied in weather and climate research. ObservedView problem details
SKF – Statistical Modelling of Mechanical Bearing Life Testing
The goal is to model and optimize bearing life testing time under constraints. The constraints are from various kinds: Number of available test machines (each machine has 2 test positions): Number of life tests to be run: Statistical distribution assumed for individual bearing life: Weibull (,) Assessed precision: the expected maximum ratio between confidence boundsView problem details
Philips – Patient Adaptive Compressed Sensing
The Problem The sampling density function in Compressed Sensing can best be optimized once the -space density is known for the object under investigation. This is characterized by an MRI scan (fast pre-acquired data set), from which the -space extent is estimated by a Fourier Transform. In addition, the data is acquired with multiple, spatially-localized,View problem details
