Toward Invisible Drones : An Ultra-HDR Optical Cloaking System

acceptedVersionPeer reviewe

Designing flipped learning implementations for electronics courses

Due to the COVID-19 pandemic during year 2020 many higher education institutes were forced to switch to remote teaching on a very short notice. The rapid change from on-campus to remote teaching showed us that effective remote teaching needs totally new forms of course implementations. The idea that one just moves the on-campus teaching to a distance learning platform without changing anything else was found to be inefficient and passivating for students. Flipped Learning Method (FLM) has been successfully utilized in many fields, including engineering education. The students’ learning is enhanced and deepened when they study the basic concepts of a subject remotely in the place and time that suits them, and the face-to-face time is reserved for issues on the higher levels of Bloom’s taxonomy. In engineering studies, the possibility to utilize technology and technological tools are important. Nowadays the technological tools, such as the internet, simulation devices and various pieces of software, are widely available to students thus enabling and supporting the FLM. The FLM has been taken into use during couple of recent years in Tampere University. The COVID-19 situation gave us a trigger to adopt FLM in our courses. We believe that FLM is very suitable to hybrid teaching, where remote and on-campus teaching are combined in the same course implementation. In this paper, we will report our experiences on the rapid change to remote teaching on year 2020, the reasons for taking FLM into use, and the FLM planning and designing process of our courses.publishedVersionPeer reviewe

Recognizing swallowing movements using a textile-based device

Dysphagia can stem from various etiologies and cause several serious complications. Instrumental evaluation methods for swallowing require special equipment not available everywhere. Thus, an instrumental means to evaluate swallowing that could be used outside a hospital setting would be critical. Dual-axis accelerometers have been utilized in earlier research to recognize swallowing movements. However, no textile-based approaches have been reported. In this study, we developed a textile-based prototype device for identifying swallowing movements. The device used accelerometers and gyroscopes, with eight sensors attached to the fabric. Two female participants were asked to perform two tasks while wearing the device around their neck: sitting still and taking 10 sips of water. The sensor attached to the middle of the thyroid notch level and the two sensors horizontally aligned to both sides of the hyoid bone level were the most accurate in recognizing swallowing movements. No sensor alone could recognize all swallows. However, all the swallows were identified using the combined data from the sensors. Thus, based on these preliminary results, it seems like a textile-based device using accelerometers and gyroscopes could identify swallowing movements.publishedVersionPeer reviewe

Printable, Transparent, and Flexible Touch Panels Working in Sunlight and Moist Environments

The ongoing revolution of touch-based user interfaces sets new requirements for touch panel technologies, including the need to operate in a wide range of environments. Such touch panels need to endure moisture and sunlight. Moreover, they often need to be curved or flexible. Thus, there is a need for new technologies suitable, for example, for home appliances used in the kitchen or the bathroom, automotive applications, and e-paper. In this work, the development of transparent and flexible touch panels for moist environments is reported. A piezoelectric polymer, poly(vinylidene difluoride) (PVDF), is used as a functional substrate material. Transparent electrodes are fabricated on both sides of a PVDF film using a graphene-based ink and spray coating. The excellent performance of the touch panels is demonstrated in moist and underwater conditions. Also, the transparent device shows very small pyroelectric response to radiative heating in comparison to a non-transparent device. Solution processable electrode materials in combination with functional substrates allow the low-cost and high-throughput manufacturing of touch panels using printing technologies.acceptedVersionPeer reviewe

Noncontact Respiration Monitoring during Sleep with Microwave Doppler Radar

This paper demonstrates the measurement of respiration waveform during sleep with a noncontact radar sensor. Instead of measuring only the respiration rate, the methods that allow monitoring the absolute respiration displacement were studied. Absolute respiration displacement can in theory be measured with a quadrature microwave Doppler radar sensor and using the nonlinear demodulation as the channel combining method. However, in this paper, relative respiration displacement measures were used as a reference. This is the first time that longer data sets have been analyzed successfully with the nonlinear demodulation method. This paper consists of whole-night recordings of three patients in an uncontrolled environment. The reference respiration data were obtained from a full polysomnography recorded simultaneously. The feasibility of the nonlinear demodulation in a real-life setting has been unclear. However, this paper shows that it is successful most of the time. The coverage of successfully demodulated radar data was ∼ 58 %-78%. The use of the nonlinear demodulation is not possible in the following cases: 1) if the chest wall displacement is too small compared with the wavelength of the radar; 2) if the radar data do not form an arc-like shape in the $IQ$ -plot; or 3) if there are large movement artifacts present in the data. Both in academic literature and in commercial radar devices, the data are processed based on the presumption that it forms either an arc or a line in the IQ -plot. Our measurements show that the presumption is not always valid.acceptedVersionPeer reviewe

Noncontact Respiration Monitoring During Sleep With Microwave Doppler Radar

This paper demonstrates the measurement of respiration waveform during sleep with a noncontact radar sensor. Instead of measuring only the respiration rate, the methods that allow monitoring the absolute respiration displacement were studied. Absolute respiration displacement can in theory be measured with a quadrature microwave Doppler radar sensor and using the nonlinear demodulation as the channel combining method. However, in this paper, relative respiration displacement measures were used as a reference. This is the first time that longer data sets have been analyzed successfully with the nonlinear demodulation method. This paper consists of whole-night recordings of three patients in an uncontrolled environment. The reference respiration data were obtained from a full polysomnography recorded simultaneously. The feasibility of the nonlinear demodulation in a real-life setting has been unclear. However, this paper shows that it is successful most of the time. The coverage of successfully demodulated radar data was ∼ 58 %-78%. The use of the nonlinear demodulation is not possible in the following cases: 1) if the chest wall displacement is too small compared with the wavelength of the radar; 2) if the radar data do not form an arc-like shape in the $IQ$ -plot; or 3) if there are large movement artifacts present in the data. Both in academic literature and in commercial radar devices, the data are processed based on the presumption that it forms either an arc or a line in the IQ -plot. Our measurements show that the presumption is not always valid.acceptedVersionPeer reviewe