Purpose - Process - People: a lean approach to biomedical manufacturing

Opportunities to improve production processes and access to markets through the implementation of lean manufacturing in biomedical manufacturing are presented. The importance of a unified definition of manufacturing, to which biomedical manufacturing is party, is emphasized, and the theory of "lean", summarized as "purpose, process, people", is elaborated. The requirements for the creation of value through the creation of flow and the elimination of wastes are highlighted in the context of biomedical manufacturing. Finally, case studies are presented to illustrate the approaches to "purpose, process, people"

Predicting perceptual transparency of head-worn devices

| openaire: EC/H2020/812719/EU//VRACEAcoustically transparent head-worn devices are a key component of auditory augmented reality systems, in which both real and virtual sound sources are presented to a listener simultaneously. Head-worn devices can exhibit high transparency simply through their physical design but in practice will always obstruct the sound field to some extent. In this study, a method for predicting the perceptual transparency of head-worn devices is presented using numerical analysis of device measurements, testing both coloration and localization in the horizontal and median plane. Firstly, listening experiments are conducted to assess perceived coloration and localization impairments. Secondly, head-related transfer functions of a dummy head wearing the head-worn devices are measured, and auditory models are used to numerically quantify the introduced perceptual effects. The results show that the tested auditory models are capable of predicting perceptual transparency and are therefore robust in applications that they were not initially designed for.Peer reviewe

Auralization of Measured Room Transitions in Virtual Reality

Funding Information: This research was supported by European Union Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement 812719. | openaire: EC/H2020/812719/EU//VRACE (Horizon 2020)To auralize a room’s acoustics in six degrees-of-freedom virtual reality (VR), a dense set of spatial room impulse response (SRIR) measurements is required, so interpolating between a sparse set is desirable. This paper studies the auralization of room transitions by proposing a baseline interpolation method for higher-order Ambisonic SRIRs and evaluating it in VR. The presented method is simple yet applicable to coupled rooms and room transitions. It is based on linear interpolation with RMS compensation, although direct sound, early reflections, and late reverberation are processed separately, whereby the input direct sounds are first steered to the relative direction-of-arrival before summation and interpolated early reflections are directionally equalized. The proposed method is first evaluated numerically, which demonstrates its improvements over a basic linear interpolation. A listening test is then conducted in six degrees-of-freedom VR, to assess the density of SRIR measurements needed in order to plausibly auralize a room transition using the presented interpolation method. The results suggest that, given the tested scenario, a 50-cm to 1-m inter-measurement distance can be perceptually sufficient.Peer reviewe

Effects of shoot pruning and inflorescence thinning on plant growth, yield and fruit quality of greenhouse tomatoes in a tropical climate

The combined effects of shoot pruning (one or two stems) and inflorescence thinning (five or ten flowers per inflorescence) on greenhouse tomato yield and fruit quality were studied during the dry season (DS) and rainy season (RS) in Central Thailand. Poor fruit set, development of undersized (mostly parthenocarpic) fruits, as well as the physiological disorders blossom-end rot (BER) and fruit cracking (FC) turned out to be the prevailing causes deteriorating fruit yield and quality. The proportion of marketable fruits was less than 10% in the RS and around 65% in the DS. In both seasons, total yield was significantly increased when plants were cultivated with two stems, resulting in higher marketable yields only in the DS. While the fraction of undersized fruits was increased in both seasons when plants were grown with a secondary stem, the proportions of BER and FC were significantly reduced. Restricting the number of flowers per inflorescence invariably resulted in reduced total yield. However, in neither season did fruit load considerably affect quantity or proportion of the marketable yield fraction. Inflorescence thinning tended to promote BER and FC, an effect which was only significant for BER in the RS. In conclusion, for greenhouse tomato production under climate conditions as they are prevalent in Central Thailand, the cultivation with two stems appears to be highly recommendable whereas the measures to control fruit load tested in this study did not proof to be advisable

Competitive Benchmarking: An IS Research Approach to Address Wicked Problems with Big Data and Analytics

Wicked problems like sustainable energy and financial market stability are societal challenges that arise from complex socio-technical systems in which numerous social, economic, political, and technical factors interact. Understanding and mitigating them requires research methods that scale beyond the traditional areas of inquiry of Information Systems (IS) “individuals, organizations, and markets” and that deliver solutions in addition to insights. We describe an approach to address these challenges through Competitive Benchmarking (CB), a novel research method that helps interdisciplinary research communities to tackle complex challenges of societal scale by using different types of data from a variety of sources such as usage data from customers, production patterns from producers, public policy and regulatory constraints, etc. for a given instantiation. Further, the CB platform generates data that can be used to improve operational strategies and judge the effectiveness of regulatory regimes and policies. We describe our experience applying CB to the sustainable energy challenge in the Power Trading Agent Competition (Power TAC) in which more than a dozen research groups from around the world jointly devise, benchmark, and improve IS-based solutions

Residual Stresses In Laser-Deposited Metal Parts

Several laser-based techniques to fabricate parts by depositing metals, ceramic powders, or a combination thereof have been developed in recent years. These fabrication techniques are incomplete and not fully useful to an operator without any predictive capability to calculate the geometries of the fabricated parts or equations to calculate their expected yield and ultimate strengths. Data concerning the energy transfer from the processing laser beam to the material powder, such as the metal vapor-plasma plume temperature and plume absorption coefficient, the efficiency of laser energy transfer and mathematical analysis for the thermal and dimensional process characteristics are unavailable. Also, the characterization of the mechanical properties of such laser-fabricated parts has just begun. A one-dimensional model to calculate the thermal and dimensional process characteristics is developed. The model accounts for the transmission of the laser beam through the plume, energy transfer in the molten phase, and the Stefan conditions at the solid-liquid and liquid-vapor interfaces. The yield and ultimate strengths of laser-fabricated stainless steel (SS 304) parts have been measured. A mathematical model is developed accounting for directionally preferred solidification to calculate the residual stresses generated in the part during solidification. © 12001 Laser Institute of America