On short-term traffic flow forecasting and its reliability

Recent advances in time series, where deterministic and stochastic modelings as well as the storage and analysis of big data are useless, permit a new approach to short-term traffic flow forecasting and to its reliability, i.e., to the traffic volatility. Several convincing computer simulations, which utilize concrete data, are presented and discussed.Comment: 8th IFAC Conference on Manufacturing Modeling, Management & Control (Troyes, France, June 2016

Plasma sprayed titanium coatings with/without a shroud

Abstract: Titanium coatings were deposited by plasma spraying with and without a shroud. The titanium coatings were then assessed by scanning electron microscopy. A comparison in microstructure between titanium coatings with and without the shroud was carried out. The results showed that the shroud played an important role in protecting the titanium particles from oxidation. The presence of the shroud led to a reduction in coating porosity. The reduction in air entrainment with t he shroud resulted in better heating of the particles, and an enhanced microstructure with lower porosity in the shrouded titanium coatings were observed compared to the air plasma sprayed counterpart

CREATING VALUE IN ADDITIVE MANUFACTURING – MODELING OF ECOSYSTEM DETERMINANTS

Despite the increasing managerial awareness for ecosystems to organize complex value propositions, little is known about how different roles can establish their business models (BM) in ecosystems. AM drives innovations in the product design and manufacturing fields predominantly across companies, indicating the eco-systemic organization of value creation without orchestrating and dominant keystone actors yet. This paper explores ecosystem determinants by analyzing the dynamic additive manufacturing (AM) paradigm. We conduct an empirical study with companies from the AM domain to visualize their value activities and define generic roles in the interdependent value creation process, adopting the e³-value methodology. By exploring these ecosystem determinants, our results aid practitioners in positioning their BMs in the AM domain and generate descriptive insights for the orchestrator BM design in a dynamic domain without orchestrating keystones

The Perils of the Learning Model For Modeling Endogenous Technological Change

Learning or experience curves are widely used to estimate cost functions in manufacturing modeling. They have recently been introduced in policy models of energy and global warming economics to make the process of technological change endogenous. It is not widely appreciated that this is a dangerous modeling strategy. The present note has three points. First, it shows that there is a fundamental statistical identification problem in trying to separate learning from exogenous technological change and that the estimated learning coefficient will generally be biased upwards. Second, we present two empirical tests that illustrate the potential bias in practice and show that learning parameters are not robust to alternative specifications. Finally, we show that an overestimate of the learning coefficient will provide incorrect estimates of the total marginal cost of output and will therefore bias optimization models to tilt toward technologies that are incorrectly specified as having high learning coefficients.Learning by doing, Experience curves, Energy models, Technological change

Robust algorithm for calibration of robotic manipulator model

The paper focuses on the robust identification of geometrical and elastostatic parameters of robotic manipulator. The main attention is paid to the efficiency improvement of the identification algorithm. To increase the identification accuracy, it is proposed to apply the weighted least square technique that employs a new algorithm for assigning of the weighting coefficients. The latter allows taking into account variation of the measurement system precision in different directions and throughout the robot workspace. The advantages of the proposed approach are illustrated by an application example that deals with the elasto-static calibration of industrial robot.AN

Additive Manufacturing, Modeling and Performance Evaluation of 3D Printed Fins for Surfboards

We demonstrate that Additive Manufacturing (3D printing) is a viable approach to rapidly prototype personalised fins for surfboards. Surfing is an iconic sport that is extremely popular in coastal regions around the world. We use computer aided design and 3D printing of a wide range of composite materials to print fins for surfboards, e.g. ABS, carbon fibre, fibre glass and amorphous thermoplastic poly(etherimide) resins. The mechanical characteristics of our 3D printed fins were found to be comparable to commercial fins. Computational fluid dynamics was employed to calculate longitudinal (drag) and tangential (turning) forces, which are important for surfboard maneuverability, stability and speed. A commercial tracking system was used to evaluate the performance of 3D printed fins under real-world conditions (i.e. surfing waves). These data showed that the surfing performance of surfboards with 3D printed fins is similar to that of surfboards with commercial fins

Initial inventory levels for a book publishing firm = Kezdőkészletek egy könyvkiadó vállalatnál

Egy könyvkiadó vállalatot vizsgálunk. A kiadó kiadványait a szokásos értékesítési láncon (kis- és nagykereskedelem) keresztül értékesíti. A kérdés az, hogy egy új könyv példányait hogyan allokálja az értékesítési láncban. Feltételezzük, hogy a kereslet ismert, Poisson-eloszlású. A készletezés költségeit szintén ismertnek tételezzük fel. Cél a költségek minimalizálása. = The aim of the paper is to analyze a practical real world problem. A publishing house is given. The publishing firm has contacts to a number of wholesaler / retailer enterprises and direct contact to customers to satisfy the market demand. The book publishers work in a project industry. The publisher faces with the problem to allocate the stocks of a given, newly published book to the wholesaler and retailer, and to hold some copies to satisfy the customers direct from the publisher. The distribution of the demand is unknown, but it can be estimated. The costs consist of inventory holding and shortage, backorder costs. The decision maker wants to minimize these relevant costs. The problem can be modeled as a one-warehouse and N-retailer supply chain with not identical demand distribution. The problem structure is similar that of a newsvendor model. It is assumed that the demand distribution follows a Poisson distribution

Advances in Additive Manufacturing, Modeling Systems and 3D Prototyping: Proceedings of the AHFE 2019 International Conference on Additive Manufacturing, Modeling Systems and 3D Prototyping, July 24-28, 2019, Washington D.C., USA

This book discusses the latest advances in digital modeling systems (DMSs) and additive manufacturing (AM) technologies. It covers applications of networked technologies, ubiquitous computing, new materials and hybrid production systems, discussing how they are changing the processes of conception, modeling and production of products and systems of product. The book emphasizes ergonomic and sustainability issues, as well as timely topics such as DMSs and AM in Industry 4.0, DMSs and AM in developing countries, DMSs and AM in extreme environments, thus highlighting future trends and promising scenarios for further developing those technologies. Based on the AHFE 2019 International Conference on Additive Manufacturing, Modeling Systems and 3D Prototyping, held on July 24-28, 2019, in Washington D.C., USA, the book is intended as source of inspiration for researchers, engineers and stakeholders, and to foster interdisciplinary and international collaborations between them