244 research outputs found
Parameter Estimation of McKibben Pneumatic Artificial Muscle and Human Intention
McKibben型空気圧ゴム人工筋は,ゴムチューブを非伸縮性のメッシュ包んだ構造を有し,内部に圧縮空気を注入することにより収縮力を発生させる.構造的利点から,外骨格デバイスなどのアクチュエータとして利用されている.近年,物理的接触により得られた筋電位等の生体情報を制御入力へフィードバックし,所望の出力を実現する外骨格デバイスが開発されている.これらのデバイスでは,人間をシステムの一部として考えるため,効率的に制御系設計をおこなう場合,人間とデバイス両方のダイナミクスを考慮した開発環境の構築が必要となる. そこで,本論文の目的は、McKibben型空気圧ゴム人工筋駆動の外骨格デバイスを対象とした制御系設計のための仮想環境を開発・整備することである.まず,空気圧ゴム人工筋モデル内に存在する未知パラメータの効率的な推定法を提案する.提案法は粒子群最適化アルゴリズムに基づいており,その探索初期点をパラメータ空間内の良好な範囲内に指定する.3種類の人工筋に対してパラメータ推定をおこない,提案法の有効性を検証する.次に,提案法により推定されたパラメータを用い,従来の人工筋モデルを負荷変動について考慮したモデルに拡張する.更に,生体情報フィードバックによる外骨格デバイスの開発を見据え,人間の動作意思を予測する推定器を作成する.この推定器は,複数の被験者から得られた筋電位を特徴量とし,サポートベクタマシンとニューラルネットワークにより3つおよび5つの動作を判別する.電気通信大学201
Reduction in BDNF from inefficient precursor conversion influences nest building and promotes depressive-like behavior in mice
Kojima, M.; Otabi, H.; Kumanogoh, H.; Toyoda, A.; Ikawa, M.; Okabe, M.; Mizui, T. Reduction in BDNF from Inefficient Precursor Conversion Influences Nest Building and Promotes Depressive-Like Behavior in Mice. Int. J. Mol. Sci. 2020, 21, 3984. https://doi.org/10.3390/ijms2111398
Plexiform neurofibroma in the hepatic hilum associated with neurofibromatosis type 1: a case report
We present an extremely rare case of plexiform neurofibroma involving the hepatic hilum. A 24-year old woman who had been diagnosed with neurofibromatosis type 1 was referred to our hospital for evaluation of an abdominal mass found on computed tomography and progressive aggravation of intermittent abdominal pain. Abdominal computed tomography revealed a multilobulated non-enhancing mass involving the celiac trunk and hepatic artery, that extended to the hepatic hilum through the hepatoduodenal ligament. Magnetic resonance imaging showed the lesion extending along the intrahepatic Glisson's sheath. Based on the imaging findings, the patient was diagnosed to have a neu-rofibroma, although sarcomatous differentiation could not be excluded. The tumor was resected, leaving behind the intrahepatic extension, with the aim of alleviating the abdominal pain and preventing obstructive jaundice. Histopathological examination revealed the diagnosis of plexiform neurofibroma. At present, three years after the surgery, the patient remains symptom-free, without any evidence of recurrence
Malignant Triton tumor in the retroperitoneal space associated with neurofibromatosis type 1: a case study
We report an extremely rare case of malignant Triton tumor developing in the retroperitoneal space in a patient with neurofibromatosis type 1. A 21-year old man who had been diagnosed with neurofibromatosis type 1 was admitted to our hospital with the chief complaint of a palpable abdominal mass. Abdominal computed tomography revealed a huge heterogeneous tumor measuring approximately 17 cm in diameter occupying the left retroperitoneal space, and numerous metastatic lesions between the left psoas muscle and the left thigh with dissolution of the left hip joint. After the diagnosis of a retroperitoneal malignant neurogenic tumor, resection of the tumor with reconstruction of the abdominal aorta was conducted, followed by postoperative transarterial infusion chemotherapy. The histopathological diagnosis was malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation, namely malignant Triton tumor. Postoperative chemotherapy was in vain and the patient died 14 months after the surgery as a result of lung metastasis
Source Selection for Cluster Weak Lensing Measurements in the Hyper Suprime-Cam Survey
We present optimized source galaxy selection schemes for measuring cluster
weak lensing (WL) mass profiles unaffected by cluster member dilution from the
Subaru Hyper Suprime-Cam Strategic Survey Program (HSC-SSP). The ongoing
HSC-SSP survey will uncover thousands of galaxy clusters to . In
deriving cluster masses via WL, a critical source of systematics is
contamination and dilution of the lensing signal by cluster {members, and by
foreground galaxies whose photometric redshifts are biased}. Using the
first-year CAMIRA catalog of 900 clusters with richness larger than 20
found in 140 deg of HSC-SSP data, we devise and compare several
source selection methods, including selection in color-color space (CC-cut),
and selection of robust photometric redshifts by applying constraints on their
cumulative probability distribution function (PDF; P-cut). We examine the
dependence of the contamination on the chosen limits adopted for each method.
Using the proper limits, these methods give mass profiles with minimal dilution
in agreement with one another. We find that not adopting either the CC-cut or
P-cut methods results in an underestimation of the total cluster mass
() and the concentration of the profile (). The level of
cluster contamination can reach as high as at
Mpc/ for low-z clusters without cuts, while employing either the P-cut or
CC-cut results in cluster contamination consistent with zero to within the 0.5%
uncertainties. Our robust methods yield a detection of the
stacked CAMIRA surface mass density profile, with a mean mass of
.Comment: 19 pages, 4 tables, 12 figures, accepted to PASJ special issu
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