Doelstelling: In kaart brengen van de risicofactoren voor het ontwikkelen van binoculaire diplopie na conventionele monovisie door middel van contactlenzen of refractiechirurgie bij presbyopen. Methode: Voor deze literatuurstudie is in maart 2017 gezocht in databanken Pubmed, ScienceDirect en Google Scholar. Artikelen zijn geïncludeerd als binoculaire diplopie door monovisie wordt beschreven. Alle patiënten die worden weergegeven in deze artikelen zijn ouder dan 40 jaar en hebben monovisie door middel van contactlenzen of refractiechirurgie. De resultaten beschrijven de oorzaken van de binoculaire diplopie, de voorgeschiedenis van de patiënt met betrekking tot strabismus en de hoogte van additie. Onderscheid wordt gemaakt tussen contactlensdragers en patiënten die refractiechirurgie hebben ondergaan. Resultaten: In deze literatuurstudie zijn zes artikelen verwerkt. Uit deze artikelen zijn 35 patiënten met binoculaire diplopie meegenomen in dit onderzoek, vijftien patiënten met contactlens geïnduceerde monovisie en twintig patiënten met refractiechirurgie geïnduceerde monovisie. De oorzaken van binoculaire diplopie (decompensatie van een heteroforie, een intermitterend strabismus die constant wordt, een verworven heterotropie, decompensatie van een N IV parese en fixation switch diplopie) geven geen grote verschillen in aantal patiënten. Een additie hoger dan twee dioptrie komt meer voor in deze patiëntengroep met binoculaire diplopie dan een lagere additie. Een positieve voorgeschiedenis met betrekking tot strabismus komt meer voor dan een negatieve voorgeschiedenis. Relevante verschillen tussen contactlensdragers en patiënten die refractiechirurgie hebben ondergaan zijn niet gevonden. Conclusie: Vanwege het gebrek aan consistente data is meer onderzoek nodig voor significante resultaten.
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In this paper, we experimentally compare orthogonal frequency-division multiplexing (OFDM) and on-off keying (OOK) modulation in the context of the IEEE 802.15.13-2023 standard at bandwidths up to 50 MHz across a Li-Fi link with distances up to 5 m and a lateral offset up to 51°. Error vector magnitude (EVM) and bit error rate (BER) evaluations confirm that the high peak-to-average power ratio (PAPR) of OFDM limits the achievable transmission distance, but it offers higher data rates due to its higher spectral efficiency. Due to the lower PAPR, OOK-based Pulsed Modulation PHY (PM-PHY) shows a significantly higher link range. As the structure of the PM-PHY is based on OFDM symbols, the two solutions may also be combined to open a wider range of use cases for optical wireless communications.
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Older adults experience visual problems owing to biological ageing or eye disease. In the Netherlands, the prevalence of visual impairments is the highest in the subgroup of nursing home residents (41.3%). These impairments influence quality of life in terms of limiting daily activities and participation in social activities. Furthermore, 63% of visual problems are defined as ‘avoidable blindness’. For this reason, screening of visual functioning in the nursing home is of major importance. Moreover, visual functioning should also be taken into account to prevent the incidence of falls.
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Purpose: To establish age-related, normal limits of monocular and binocular spatial vision under photopic and mesopic conditions. Methods: Photopic and mesopic visual acuity (VA) and contrast thresholds (CTs) were measured with both positive and negative contrast optotypes under binocular and monocular viewing conditions using the Acuity-Plus (AP) test. The experiments were carried out on participants (age range from 10 to 86 years), who met pre-established, normal sight criteria. Mean and ± 2.5σ limits were calculated within each 5-year subgroup. A biologically meaningful model was then fitted to predict mean values and upper and lower threshold limits for VA and CT as a function of age. The best-fit model parameters describe normal aging of spatial vision for each of the 16 experimental conditions investigated. Results: Out of the 382 participants recruited for this study, 285 participants passed the selection criteria for normal aging. Log transforms were applied to ensure approximate normal distributions. Outliers were also removed for each of the 16 stimulus conditions investigated based on the ±2.5σ limit criterion. VA, CTs and the overall variability were found to be age-invariant up to ~50 years in the photopic condition. A lower, age-invariant limit of ~30 years was more appropriate for the mesopic range with a gradual, but accelerating increase in both mean thresholds and intersubject variability above this age. Binocular thresholds were smaller and much less variable when compared to the thresholds measured in either eye. Results with negative contrast optotypes were significantly better than the corresponding results measured with positive contrast (p < 0.004). Conclusions: This project has established the expected age limits of spatial vision for monocular and binocular viewing under photopic and high mesopic lighting with both positive and negative contrast optotypes using a single test, which can be implemented either in the clinic or in an occupational setting.
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Over 40% of nursing home residents in the Netherlands are estimated to have visual impairments. In this study, light conditions in Dutch nursing homes were assessed in terms of horizontal and vertical illuminances and colour temperature. Results showed that in the seven nursing homes vertical illuminances in common rooms fell significantly below the 750 lx reference value in at least 65% of the measurements. Horizontal illuminance measurements in common rooms showed a similar pattern. At least 55% of the measurements were below the 750 lx threshold. The number of measurements at the window zone was significantly higher than the threshold level of 750 lx. Illuminances in the corridors fell significantly below the 200 lx threshold in at least three quarters of the measurements in six of the seven nursing homes. The colour temperature of light fell significantly below the reference value for daylight of 5000 K with median scores of 3400 to 4500 K. A significant difference in colour temperature was found between recently constructed nursing homes and some older homes. Lighting conditions of the examined nursing homes were poor. With these data, nursing home staff have the means to improve the lighting conditions, for instance, by encouraging residents to be seated next to a window when performing a task or during meals.
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This report is the final report for the FPGA accelerated PID controller, part of the Distributed Control Systems project. This project runs within the Lectoraat Robotics and High Tech Mechatronics of Fontys Hogeschool Engineering Eindhoven. The Lectoraat has the goal to develop applicable knowledge to support education and industry. This knowledge is acquired with projects run in conjunction with the industry. The report will go into detail for the software designed for this project, not the hardware design. This report is intended for follow up students working on the Distributed Control Systems project. Within this report the assumption is made that the reader is at least familiar with the terms EtherCAT, FPGA, Linux and PID controllers. However for each part a small basic introduction is included. For readers looking for the accomplishments in this project, the results are in chapter six. Following are short descriptions of the chapters in this report. The first chapter will give a short introduction to the project. It talks about why the project was conceived, where the project was done and what the expected end result is. The second chapter, the problem definition, talks about how the project has been defined, what is included and what is not and how the customer expects the final product to function and look like. The third chapter details the methodology used during this project. All the research preformed for this project will be described in the forth chapter. This chapter goes into the research into the Xilinx Zynq 7000 chip, Beckhoff's EtherCAT system, how the Serial Peripheral Interface works and how a PID controller functions. Following in chapter five the design is expanded upon. First the toolchain for building for the Zynq chip is explained. This is followed by and explanation of the different software parts that have been designed. Finally chapters six and seven provide the results and the conclusions and recommendations for this project.
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Twirre is a new architecture for mini-UAV platforms designed for autonomous flight in both GPS-enabled and GPS-deprived applications. The architecture consists of low-cost hardware and software components. High-level control software enables autonomous operation. Exchanging or upgrading hardware components is straightforward and the architecture is an excellent starting point for building low-cost autonomous mini-UAVs for a variety of applications. Experiments with an implementation of the architecture are in development, and preliminary results demonstrate accurate indoor navigation
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Business innovation is a multidisciplinary area of expertise that bridges the gap between traditional areas of study such as business administration, organizational studies, marketing, design, engineering and entrepreneurship. Business innovation focuses on creating, accelerating and managing new and sustainable business models through innovation (Crossan and Apaydin, 2010; Keeley, Walters, Pikkel, and Quinn, 2013).
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‘Creating the Difference’ is the theme of the 2014 edition of the Chi Sparks conference. It is also the challenge that the Human-Computer Interaction (HCI) community is facing today. HCI is a creative field where practitioners engage in design, production, and evaluation of interactions between people and digital technology. Creating excellent interfaces for people, they make a difference in media and systems that people are eager to use. Usability and user experience are fundamental for achieving this, as are abilities at the forefront of technology, but key to a successful difference is getting the right concepts, addressing genuine, intrinsic, human needs. Researchers and practitioners contribute to this area from theory as well as practice by sharing, discussing, and demonstrating new ideas and developments. This is how HCI creates a difference for society, for individuals, businesses, education, and organizations. The difference that an interactive product or service makes might lie in the concept of it but also in the making, the creation of details and the realisation. It is through powerful concepts and exceptional quality of realisation that innovation is truly achieved. At the Chi Sparks 2014 conference, researchers and practitioners in the HCI community convene to share and discuss their efforts on researching and developing methods, techniques, products, and services that enable people to have better interactions with systems and other people. The conference is hosted at The Hague University of Applied Sciences, and proudly built upon the previous conferences in Arnhem (2011) and Leiden (2009). Copyright van de individuele papers ligt bij de betreffende auteurs.
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The finding of poor lighting conditions in nursing homes in combination with a high prevalence of visual problems (with cataract found to be the most common age related pathology), stretches the need of enhanced awareness of eye care by professional caregivers.
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