MKB-Innovatie via Sociale Netwerken: De Casus van een Community of Entrepreneurship

Innovatie vergt kennis. Door een gebrek aan tijd en middelen is deze kennis voor MKB-ers vaak moeilijk te ontsluiten. Vanuit deze uitdaging zijn Communities of Entrepreneurship (CoE) ontstaan; een netwerk van ondernemende mensen, die ideeën, passie en inspiratie delen om elkaar te empoweren in het realiseren van ondernemingsdoelen. Benieuwd hoe

Response of Plate Structures to Close-Range Blast Loading

Since 2008, the Department of Homeland Security has been investigating the failure patterns of thin aluminum structures from close-range blasts (\u3c10in). In order to improve Finite Element models, a parametric study of various simulation techniques using LS-DYNA was done and the results compared to physical testing data from the Aberdeen Test Center. Variations included element sizes, use of solid versus shell elements, variably concentrated mesh densities, and plastic-kinematic versus Johnson-Cook material models. While results were reasonably close to physical data, the study showed a overall lack of sensitivity to these changes, suggesting a purely Lagrangian simulation method may not be as ideal for this type of analysis as a coupled fluid-structure interaction model, such as Arbitrary Lagrangian Eulerian (ALE)

Arcflow formulations and constraint generation frameworks for the two-bar charts packing problem

We consider the two-bar charts packing (2-BCPP), a recent combinatorial optimization problem whose aim is to pack a set of one-dimensional items into the minimum number of bins. As opposed to the well-known bin packing problem, pairs of items are grouped to form bar charts, and a solution is only feasible if the first and second items of every bar chart are packed in consecutive bins. After providing a complete picture of the connections between the 2-BCPP and other relevant packing problems, we show how we can use these connections to derive valid lower and upper bounds for the problem. We then introduce two new integer linear programming (ILP) models to solve the 2-BCPP based on a non-trivial extension of the arcflow formulation. Even though both models involve an exponential number of constraints, we show that they can be solved within a constraint generation framework. We then empirically evaluate the performance of our bounds and exact approaches against an ILP model from the literature and demonstrate the effectiveness of our techniques, both on benchmarks inspired by the literature and on new classes of instances that are specifically designed to be hard to solve. The outcomes of our experiments are important for the packing community because they indicate that arcflow formulations can be used to solve targeted packing problems with precedence constraints and also that some of these formulations can be solved with constraint generation

Arcflow formulations and constraint generation frameworks for the two-bar charts packing problem

We consider the two-bar charts packing (2-BCPP), a recent combinatorial optimization problem whose aim is to pack a set of one-dimensional items into the minimum number of bins. As opposed to the well-known bin packing problem, pairs of items are grouped to form bar charts, and a solution is only feasible if the first and second items of every bar chart are packed in consecutive bins. After providing a complete picture of the connections between the 2-BCPP and other relevant packing problems, we show how we can use these connections to derive valid lower and upper bounds for the problem. We then introduce two new integer linear programming (ILP) models to solve the 2-BCPP based on a non-trivial extension of the arcflow formulation. Even though both models involve an exponential number of constraints, we show that they can be solved within a constraint generation framework. We then empirically evaluate the performance of our bounds and exact approaches against an ILP model from the literature and demonstrate the effectiveness of our techniques, both on benchmarks inspired by the literature and on new classes of instances that are specifically designed to be hard to solve. The outcomes of our experiments are important for the packing community because they indicate that arcflow formulations can be used to solve targeted packing problems with precedence constraints and also that some of these formulations can be solved with constraint generation

Blockchain in the Hospitality and Tourism Industry

This chapter will provide information on what Blockchain is and why it is used. It describes the basic concepts underlying Blockchain technology, such as distributed ledgers, consensus mechanisms, mining, smart contracts, P2P, and the classification of existing Blockchain systems. Next, it explores Blockchain applications in general, in businesses and society. Blockchain maybe used e.g., for fundraising, in education, and for provenance and authenticity registration. The last part of the chapter is devoted to application of Blockchain in general to applications in the hospitality and tourism industry. It considers how Blockchain makes it possible to create new types of platforms where transactions take place and the delivery of \u27digital assets\u27, such as a hotel room booking, is not dependent on an intermediary. Other topics covered are tokenization, and the use of Blockchain in tracking baggage, loyalty programs, rating and reviews, payments, and digital identity