96 research outputs found

    Three-Dimensional Imaging Method Incorporating Range Points Migration and Doppler Velocity Estimation for UWB Millimeter-Wave Radar

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    High-resolution, short-range sensors that can be applied in optically challenging environments (e.g., in the presence of clouds, fog, and/or dark smog) are in high demand. Ultrawideband (UWB) millimeter-wave radars are one of the most promising devices for the above-mentioned applications. For target recognition using sensors, it is necessary to convert observational data into full 3-D images with both time efficiency and high accuracy. For such conversion algorithm, we have already proposed the range points migration (RPM) method. However, in the existence of multiple separated objects, this method suffers from inaccuracy and high computational cost due to dealing with many observed RPs. To address this issue, this letter introduces Doppler-based RPs clustering into the RPM method. The results from numerical simulations, assuming 140-GHz band millimeter radars, show that the addition of Doppler velocity into the RPM method results in more accurate 3-D images with reducing computational costs

    Research ethics consultation : an attempt and 5-year experience in a Japanese University Hospital

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    Objective: Research ethics consultation is an advisory activity that differs from ethics committees, and its role is not yet widely known in Japan. Research ethics consultations were started in 2012 by members of the Clinical Trial Center of Tokushima University Hospital, a support section for clinical trials. We analyzed the research ethics consultation records from Tokushima University Hospital during the 5-year period of 2012–2016 to examine the Japanese context of research ethics consultation. Results: During the study period, 125 research ethics consultations were carried out, 115 (91%) before starting studies. All but one request were from investigators at Tokushima University. The main issue was compatibility with guidance and regulations (n = 74, 67.2%), such as ethical handling of human biological specimens and information utilized in research; only 6 (4.8%) requests involved research ethics issues that investigators face in their research. Therefore, it is necessary to expand the consultation function, with a nationwide system of consultant education and data sharing. Moreover, standardization of consultation should be considered

    Hypomagnesemia due to Renal Magnesium Wastage of Unknown Etiology

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    A twenty-two year old woman, investigated because of tetanic convulsion and refractory hypocalcemia, was shown to have hypomagnesemia, hypokalemia, hypocalciuria and hypophosphaturia. The patient sometimes had loose stool but no steatorrhea. Bowel absorption test of D-Xylose, 131I-triolein and 47Ca were in the normal range. Relative hypermagnesuria was observed despite of hypomagnesemia. Renal function was normal. Parathyroid hormone level was quite low but showed a rapid increase after the injection of magnesium supplement. Normal responsiveness to parathyroid hormone was observed in the kidney. Oral administration of magnesium supplement resulted in relief of subjective symptoms as well as normal serum levels of calcium and potassium. During this period, serum magnesium rose up but never reached the normal level. These findings suggested that renal magnesium wastage of unknown etiology was the significant factor contributing to the hypomagnesemia and that hypocalcemia was probable due to impaired serection of PTH. The mechanism of the hypokalemia observed with the magnesium depletion remains unknown

    Promotion of clinical trials before / after CTA

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    Background : Enforcement of the 2018 Clinical Trials Act (CTA) in Japan resulted in strict and complicated regulations surrounding intervention studies. Few Japan-specific measures have been developed to promote intervention studies in Japan despite concerns about CTA’s negative influence on such studies. Therefore, this study examined the changes in academic investigators’ interest in conducting clinical studies before and after enforcement of the CTA to determine measures to promote specified clinical trials. Methods : We conducted a questionnaire survey with investigators belonging to the Institute of Biomedical Sciences, Tokushima University Graduate School, before and after enforcement of the CTA. Results : Investigators had lesser interest in intervention studies in the post-questionnaire survey (post) group than in the pre-questionnaire survey (pre) group. Their desire for “project management” was significantly higher in the post-group than in the pre-group. Their desire for “support for preparing documents when conducting specified clinical trials” was significantly higher in the group interested in conducting specified clinical trials than that in the not-interested group. Conclusion : We revealed that investigators were highly interested in “project management” and “support for preparing documents when conducting specified clinical trials” after enforcement of the CTA. Measures for these desires may promote specified clinical trials

    Optical and Near-Infrared Photometry of Nova V2362 Cyg : Rebrightening Event and Dust Formation

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    We present optical and near-infrared (NIR) photometry of a classical nova, V2362 Cyg (= Nova Cygni 2006). V2362 Cyg experienced a peculiar rebrightening with a long duration from 100 to 240 d after the maximum of the nova. Our multicolor observation indicates an emergence of a pseudophotosphere with an effective temperature of 9000 K at the rebrightening maximum. After the rebrightening maximum, the object showed a slow fading homogeneously in all of the used bands for one week. This implies that the fading just after the rebrightening maximum ( less or equal 1 week ) was caused by a slowly shrinking pseudophotosphere. Then, the NIR flux drastically increased, while the optical flux steeply declined. The optical and NIR flux was consistent with blackbody radiation with a temperature of 1500 K during this NIR rising phase. These facts are likely to be explained by dust formation in the nova ejecta. Assuming an optically thin case, we estimate the dust mass of 10^(-8) -- 10^(-10) M_solar, which is less than those in typical dust-forming novae. These results support the senario that a second, long-lasting outflow, which caused the rebrightening, interacted with a fraction of the initial outflow and formed dust grains.Comment: 6 pages, 4 figures, 2010, PASJ, 62, 1103--1108, in pres

    A Study on Tuning PI Parameters Based on Communication Delay Time for Small DC Motor Control System through IP Network

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    In tuning PI controller for a DC motor control system through IP network, it is needed to know dead time in the system, although delay time is fluctuated. In this work, we study an approximate value of dead time when controlling through networks varying under exponential and log-normal distributions. As a result, it has been found that the first quartile can be approximately expressed as the dead time in cases that standard deviation is small

    The 2006 November outburst of EG Aquarii: the SU UMa nature revealed

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    We report time-resolved CCD photometry of the cataclysmic variable EG Aquarii during the 2006 November outburst During the outburst, superhumps were unambiguously detected with a mean period of 0.078828(6) days, firstly classifying the object as an SU UMa-type dwarf nova. It also turned out that the outburst contained a precursor. At the end of the precursor, immature profiles of humps were observed. By a phase analysis of these humps, we interpreted the features as superhumps. This is the second example that the superhumps were shown during a precursor. Near the maximum stage of the outburst, we discovered an abrupt shift of the superhump period by {\sim} 0.002 days. After the supermaximum, the superhump period decreased at the rate of P˙/P\dot{P}/P=8.2×105-8.2{\times}10^{-5}, which is typical for SU UMa-type dwarf novae. Although the outburst light curve was characteristic of SU UMa-type dwarf novae, long-term monitoring of the variable shows no outbursts over the past decade. We note on the basic properties of long period and inactive SU UMa-type dwarf novae.Comment: 9 pages, 7 figures, accepted for PAS
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