218 research outputs found

    Towards embedded control for resonant scanning MEMS micromirror

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    This paper describes the design and realization of an electrostatic actuated MEMS mirror operating at a resonance frequency of 23.5 KHz with a PLL feedback loop. The design is based upon a thorough understanding of the (non-linear) dynamical behavior of the mirror. Using an external position sensitive device (PSD) the proper working of the PLL is demonstrated. Next we study the possibility to replace the PSD sensor with an embedded capacitive phase-angle sensor. We show measurements of capacitance changes with large parasitic influences while actuating the mirror in a feed forward mode. This demonstrates the feasibility of a fully embedded control for a resonant scanning MEMS mirror. Keywords: MEMS micromirror; laser display; raster scanning, capacitive tilt-angle sensor; PLL\ud \u

    Wayfinding for cycle highways: Assessing e-bike users’ experiences with wayfinding along a cycle highway in the Netherlands.

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    In many regions, governments are motivating increased bicycle ridership by designing new and improving existing bicycle infrastructure. Cycle highways are an effective and cost-efficient type of bicycle-specific infrastructure that are designed to provide a functional connection between places where people work, go to school and live. One important element of developing high quality cycle highways is the development of an effective wayfinding system which allows current, potential, and new users to clearly identify and navigate a bicycle network. The wayfinding design standards used for conventional bicycle infrastructure may not be compatible for cycle highways, which encourage cyclists to travel at relatively higher speeds. This may warrant introducing specific wayfinding signage compatible for this new type of bicycle infrastructure. This study uses qualitative analysis including field observations, ride-along videos, and semi-structured interviews, to assess electrically assisted pedal bicycle (e-bike) users' opinions and experiences with wayfinding signage along a pilot cycle highway route located between Tilburg and Waalwijk in the Netherlands. In the summer of 2018, base-line observations and interviews were administered with twelve e-bike users who were unfamiliar with the route to assess their experiences with conventional signage for cyclists before changes were made to the wayfinding system. Follow-up observations were held in the fall, after the installation of two new pilot wayfinding systems that were specifically designed to accommodate cycle highway users. Initial findings suggest that the changes made to the location, size and clarity of the signage improve cyclists' overall experiences, and that cyclists' perceptions of the built environment are important. Specifically, it became easier for users to navigate the route, their overall travel related stress decreased, and several participants perceived shorter travel times. Policy makers and transportation planners are likely to be interested in the results of this study as they reveal how specific improvements to wayfinding along cycle highways not only help improve navigation, but also positively influence cyclists' overall comfort and stress

    Shared micro-mobility and transport equity: A case study of three European countries

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    Shared micro-mobility services (e.g., shared bikes/e-bikes/e-scooters) have the potential to facilitate transport equity by offering available travel modes for transport disadvantaged groups. The achievement of this goal requires disadvantaged people to be able to use and benefit from shared micro-mobility equally compared with others. However, while many studies have explored the equity impact of shared micro-mobility from the perspective of its spatially and socially unequal usage, how its use can help alleviate transport poverty remains unclear. This study provides a more comprehensive picture of the role that shared micro-mobility services play on transport equity by investigating the influential factors of shared micro-mobility use and its impact on perceived transport poverty between different income groups. We developed regression models using data from an online survey conducted in 2022 in three European cities (Malmö, Manchester, and Utrecht). The results suggest that some transport disadvantaged groups (the elderly, females, car non-owners, and suburban residents) used shared micro-mobility less than others in our sample. Shared micro-mobility use shows little potential in promoting the users' accessibility and travel affordability. Nonetheless, shared e-scooters/e-mopeds have a great potential in facilitating transport equity by favoring low-income users' mobility equally or more greatly compared with that of high-income users

    Clonal Patterns Between Pouch Neoplasia and Prior Colorectal Neoplasia in Inflammatory Bowel Disease Patients:An Exploratory Cohort Study

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    Prior colorectal neoplasia is the strongest predictor of pouch neoplasia in inflammatory bowel disease, but the underlying mechanism is unknown. We observed clonality between colorectal and pouch neoplasia in 30% of patients, indicating that most pouch neoplasia develops clonally independent from prior colorectal lesions.</p

    High-temperature ferromagnetism of spsp electrons in narrow impurity bands: Application to CaB6_6

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    Ferromagnetism with high Curie temperature TcT_c, well above room temperature, and very small saturation moment has been reported in various carbon and boron systems. It is argued that the magnetization must be very inhomogeneous with only a small fraction of the sample ferromagnetically ordered. It is shown that a possible source of high TcT_c within the ferromagnetic regions is itinerant electrons occupying a narrow impurity band. Correlation effects do not reduce the effective interaction which enters the Stoner criterion in the same way as in a bulk band. It is also shown how, in the impurity band case, spin wave excitations may not be effective in lowering TcT_c below its value given by Stoner theory. These ideas are applied to CaB6_6 and a thorough review of the experimental situation in this material is given. It is suggested that the intrinsic magnetism of the B2_2 and O2_2 dimers might be exploited in suitable structures containing these elements.Comment: 26 pages, 2 figure

    Serbian pig sector: an overview : fact finding mission: opportunities for collaboration between Serbia and The Netherlands

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    The Dutch Embassy in Belgrade, Serbia, requested Wageningen UR Livestock Research (WLR) to organize a fact finding mission to the pig sector in Serbia. The goal of the mission was to identify opportunities for Dutch companies and knowledge institutes to investment in and collaborate with the Serbian pig production chain. This report contains the findings of this mission. The information was gathered by on-site visits and interviews with Serbian experts in the pig production chain

    Detecting Mandible Fractures in CBCT Scans Using a 3-Stage Neural Network

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    After nasal bone fractures, fractures of the mandible are the most frequently encountered injuries of the facial skeleton. Accurate identification of fracture locations is critical for effectively managing these injuries. To address this need, JawFracNet, an innovative artificial intelligence method, has been developed to enable automated detection of mandibular fractures in cone-beam computed tomography (CBCT) scans. JawFracNet employs a 3-stage neural network model that processes 3-dimensional patches from a CBCT scan. Stage 1 predicts a segmentation mask of the mandible in a patch, which is subsequently used in stage 2 to predict a segmentation of the fractures and in stage 3 to classify whether the patch contains any fracture. The final output of JawFracNet is the fracture segmentation of the entire scan, obtained by aggregating and unifying voxel-level and patch-level predictions. A total of 164 CBCT scans without mandibular fractures and 171 CBCT scans with mandibular fractures were included in this study. Evaluation of JawFracNet demonstrated a precision of 0.978 and a sensitivity of 0.956 in detecting mandibular fractures. The current study proposes the first benchmark for mandibular fracture detection in CBCT scans. Straightforward replication is promoted by publicly sharing the code and providing access to JawFracNet on grand-challenge.org
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