313 research outputs found

    Studies on Thiourea Derivatives of Fatty Acids

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    Analyzing the Development of a Remote Debate Program Using Video Annotation through a Systems Approach

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    This study aims to apply a systems approach to analyze the development of an education system for remote asynchronous debates. Although several studies have applied a systems approach to various objects, they attempted to improve projects using the approach by intention. However, in our study, the use of a systems approach was an unintentional part of the process, with stakeholders not being explicitly aware of the concepts behind systems thinking. In the midst of the process, a variety of systems thinking methods were partially adopted, making the project more systemic; however, the project was not oriented to follow specific problem-solving techniques. An educational program and information system for education support with sufficient systemic properties was created with such a systems approach. We propose that working on a problem with significant underlying systemic properties may help one to naturally adopt a systems approach

    Voice Over Sensor Networks

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    Wireless sensor networks have traditionally focused on low duty-cycle applications where sensor data are reported periodically in the order of seconds or even longer. This is due to typically slow changes in physical variables, the need to keep node costs low and the goal of extending battery lifetime. However, there is a growing need to support real-time streaming of audio and/or low-rate video even in wireless sensor networks for use in emergency situations and shortterm intruder detection. In this paper, we describe a real-time voice stream-capability in wireless sensor networks and summarize our deployment experiences of voice streaming across a large sensor network of FireFly nodes in an operational coal mine. FireFly is composed of several integrated layers including specialized low-cost hardware, a sensor network operating system, a real-time link layer and network scheduling. We are able to provide efficient support for applications with timing constraints by tightly coupling the network and task scheduling with hardware-based global time synchronization. We use this platform to support 2-way audio streaming concurrently with sensing tasks. For interactive voice, we investigate TDMA-based slot scheduling with balanced bi-directional latency while meeting audio timeliness requirements. Finally, we describe our experimental deployment of 42 nodes in a coal mine, and present measurements of the end-to-end throughput, jitter, packet loss and voice quality

    ENERGETICS APPROACH TO FATIGUE BEHAVIOR OF WOODEN JOINT USING DOUBLE-SIDED ADHESIVE TAPE

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    The authors have previously studied the possibility of the use of industrial double-sided adhesive tape as a method for jointing wooden panel to wooden framework. The mechanical performance of joints formed by such methods is comparable to that of nailed joint under static load conditions. However, the mechanical performance of such joints has not been evaluated under cyclic load conditions. This study was conducted to investigate this aspect of their performance. Double-shear specimens were prepared by bonding wooden panel to wooden framework using two types of adhesive tape with different substrates. Specimens were also prepared with wooden dowels to strengthen their jointing performance. The joint specimens were subjected to cyclic shear loading testing. The results of the tests were analyzed from an energetics perspective, and the shear deformability of the specimens at failure was estimated. The test results indicate that both the specimens formed using adhesive tape and those formed using wooden dowels had fatigue properties comparable to nailed joint specimens. A tendency for the shear deformability caused by cyclic loading to increase with the stress level was observed. It was possible to estimate the shear deformability by evaluating the energy absorption capacity of the joints from an energetics standpoint

    3D Modeling and 3D Materialization of Fluid Art That Occurs in Very Short Time

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    19th IFIP TC 14 International Conference, ICEC 2020, Xi'an, China, November 10–13, 2020.Proceedings of ICEC2020We have been creating artworks called “liquid art” utilizing liquid dynamics phenomena. One of the liquid artworks is “Sound of Ikebana” which is created by giving sound vibration to color paints and shooting the phenomenon by a high-speed camera, which has been evaluated as “the artwork includes Japanese beauty.” To investigate further why it is evaluated in such a way and also to seek the possibility of its application in society, we tried to materialize it into 3D objects. As the phenomenon occurs in a very short time of less than one second, we have developed a specific experimental environment consisting of multiple high-speed cameras surrounding a speaker where the phenomenon occurs. Among various technologies to reconstruct the 3D model from multiple 2D images, we have chosen a method called Phase-Only Correlation and developed a 3D mesh model of a snapshot of “Sound of Ikebana.” Also using a 3D printer we have successfully obtained 3D materialized “Sound of Ikebana.

    Creation of Fluid Art “Sound of Ikebana” under Microgravity Using Parabolic Flight

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    [2022 International Conference for ADADA + CUMULUS] 26 - 27 November 2022, OnlineArt has been at the center of human spiritual life, and therefore, art in the future space age is an exciting subject. The authors, led by an artist, have been creating video artwork "Sound of Ikebana, " made by giving sound vibration to fluid and shooting it with a high-speed camera. To study its shape under zero gravity, we conducted the generation of the artwork under microgravity realized by parabolic flight. As the sound source, we used the birth cries of newborn babies, which also symbolize the future. We confirmed that a new shape that has never existed is created. Furthermore, a three-dimensional artwork was created by shooting the phenomenon from multiple viewpoints

    Pole Exercise on Thorax Cage and its Influence on the Flexibility in Low Back-pain Patients

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    Background: Low back pain (LBP) has been common clinical and neuromusculoskeletal disorders. Authors have continued clinical practice and research concerning LBP and rehabilitation, associated with the efficacy of pole exercise movement and application. Methods: Subjects were 18 LBP patients with 46.6 ± 5.8 years old. They were randomly assigned to two groups, which are pole exercise and control groups. Group 1 continued axial rotation, lateral bending and forward/backward rotation along Moriyasu method 10 times 3 sets per day for 2 weeks. Group 2 continued Slump Stretching and Gluteus Stretch in the same way. The biomarkers include Finger Floor Distance (FFD) and Numerical Rating Scale (NRS) before and after the intervention. Results: Both groups showed significant improved results in FFD and NRS between before and after the intervention. Group 1 showed significant improved results in FFD and NRS after intervention, which were 5.2 ± 9.4 cm vs. 15.7 ± 7.0 cm, and 3.0 ± 2.1 vs. 5.1 ± 1.3 respectively. Conclusion: The results suggested that continuous daily pole exercise would be effective for improved flexibility and motor function for thorax cage and vertebrae. Further study and comparative evaluation among LBP, pole exercise, FFD and other biomarkers will be expected in the future

    Proposal and Demonstration of Free-Space Optical Communication Using Photonic Crystal Surface-Emitting Lasers

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    We propose and demonstrate free-space optical (FSO) communication using photonic crystal surface-emitting lasers (PCSELs). Unlike other types of conventional semiconductor lasers, such as edge-emitting lasers (EELs) and vertical-cavity surface-emitting lasers (VCSELs), PCSELs achieve much larger area single-mode coherent lasing, and this unique feature enables high-power (>watt) and lens-free operations at the same time. To date, these advantages have been recognized to be game changing, especially in light detection and ranging (LiDAR) and laser processing applications. In this work, we show that FSO communication can also benefit from these advantages of PCSELs; more specifically, conventional transmitters that include low-power semiconductor lasers, optical lenses, and fiber-based amplifiers could be replaced with a single PCSEL. Since fiber amplifiers usually consist of bulky components and have low conversion efficiencies, PCSELs can offer more space- and power-saving solutions. Moreover, the narrow beam divergence angles directly obtained from large-area single-mode PCSELs can also eliminate the need for lens systems on the transmitter side. To experimentally verify these potential advantages, we performed FSO transmission experiments based on PCSELs and successfully transmitted 480-MHz and 864-MHz orthogonal frequency division multiplexed (OFDM) signals over 1.1 m using a 500-μm PCSEL in a lens-free transmitter configuration. We believe that PCSELs open new possibilities and choices in FSO communication
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