Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 7 )

2018 ( 11 )

2017 ( 14 )

2016 ( 21 )

Custom range...

Search Results: 1 - 10 of 2200 matches for " Hirofumi Aoki "
All listed articles are free for downloading (OA Articles)
Page 1 /2200
Display every page Item
Evaluation of Driver Distraction with Changes in Gaze Direction Based on a Vestibulo-Ocular Reflex Model  [PDF]
Le Anh Son, Hirofumi Aoki, Tatsuya Suzuki
Journal of Transportation Technologies (JTTs) , 2017, DOI: 10.4236/jtts.2017.73022
Abstract: With the aim of improving parameter identification and, eventually, evaluating driver distraction with changes in gaze direction, we applied a genetic algorithm (GA) method to identify parameters for an existing vestibulo-ocular reflex (VOR) model. By changing the initial inputs to the GA and fixing two parameters pertaining to the horizontal direction, we achieved improved parameter identification with a lower mean-square error. The influence of driver distraction on eye movement with changes in gaze direction was evaluated from the difference between the predicted and observed VOR in the vertical axis. When a driver was given an additional mental workload, the mean-square error between the measured and simulated values was bigger than that in the absence of the mental workload. This confirmed the relationship between driver distraction and eye movement in the vertical direction. We hope that this method can be applied in evaluating driver distraction.
Effect of Difference in Form of Driving Support Agent to Driver’s Acceptability
—Driver Agent for Encouraging Safe Driving Behavior (2)

Takahiro Tanaka, Kazuhiro Fujikake, Takashi Yonekawa, Makoto Inagami, Fumiya Kinoshita, Hirofumi Aoki, Hitoshi Kanamori
Journal of Transportation Technologies (JTTs) , 2018, DOI: 10.4236/jtts.2018.83011
Abstract: In recent years, the number of traffic accidents caused by elderly drivers has increased in Japan. However, a car is an important mode of transportation for the elderly. Therefore, to ensure safe driving, a system that can assist elderly drivers is required. In this study, we propose a driver-agent system that provides support to elderly drivers during and after driving and encourages them to improve their driving. This paper describes the prototype system based on the analysis of the teaching records of a human instructor, and the subjective evaluation of driving support to elderly and non-elderly driver from three different agent forms, a voice, visual, and robot. The result revealed that the robot form is more noticeable, familiar, and acceptable to the elderly and non-elderly than other forms.
Two-Orbital Model Explains the Higher Transition Temperature of the Single-Layer Hg-Cuprate Superconductor Compared to That of the La-Cuprate Superconductor
Hirofumi Sakakibara,Hidetomo Usui,Kazuhiko Kuroki,Ryotaro Arita,Hideo Aoki
Physics , 2010, DOI: 10.1103/PhysRevLett.105.057003
Abstract: In order to explore the reason why the single-layered cuprates, La$_{2-x}$(Sr/Ba)$_x$CuO$_4$ ($T_c\simeq$ 40K) and HgBa$_2$CuO$_{4+\delta}$ ($T_c\simeq$ 90K), have such a significant difference in $T_c$, we study a two-orbital model that incorporates the $d_{z^2}$ orbital on top of the $d_{x^2-y^2}$ orbital. It is found, with the fluctuation exchange approximation, that the $d_{z^2}$ orbital contribution to the Fermi surface, which is stronger in the La system, works against d-wave superconductivity, thereby dominating over the effect of the Fermi surface shape. The result resolves the long-standing contradiction between the theoretical results on Hubbard-type models and the experimental material dependence of $T_c$ in the cuprates.
Two-orbital view on the origin of the material dependence of Tc in the single-layer cuprates
Hirofumi Sakakibara,Hidetomo Usui,Kazuhiko Kuroki,Ryotaro Arita,Hideo Aoki
Physics , 2013, DOI: 10.1088/1742-6596/400/2/022100
Abstract: Using the dx2-y2+dz2 two orbital model of the high Tc cuprates obtained from the first-principle calculation, we show that the material dependence of the Fermi surface shape can be understood by the degree of the mixture between the dx2-y2$ and the dz2 orbitals. We explain, through investigating the tightbinding hopping integrals, why some cuprates have square shaped Fermi surface, while others have more rounded ones. From this viewpoint, we explain the experimentally observed correlation between the curvature of the Fermi surface and Tc.
Clear cell carcinoma of salivary gland type presenting as an endotracheal polypoid tumor  [PDF]
Kazuhiro Tabata, Michiyo Higashi, Shinichi Kitajima, Ikumi Kitazono, Tsubasa Hiraki, Tsunayuki Otsuka, Masaya Aoki, Kazuhiro Wakita, Hirofumi Nakayama, Suguru Yonezawa, Junya Fukuoka
Case Reports in Clinical Medicine (CRCM) , 2013, DOI: 10.4236/crcm.2013.22043

A 66-year-old woman presented with a 2-year history of asthma has progression of dyspnea within a week, and a computed tomography (CT) revealed an endotracheal tumor at level of aortic arch. The resected tumor, measured by 18 × 12 × 10 mm, has histologically malignant features including frank invasion with desmoplastic stroma and foci of necrosis. Presence of glycogen and mucin was confirmed by periodic acid-Schiff (PAS) and diastase PAS staining. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin (CK) 7 and AE1/3, focally positive for CK5/6 and CK14, but negative for CK20. Thyroid transcription factor-1 (TTF-1), Napsin A, and SP-A, indicating lung parenchymal origin were all negative. Other muscular markers, neuroendocrine markers, renal cell carcinoma markers, and markers related to perivascular epithelioid cell tumors were all negative. Postoperative systemic examination suggests no primary tumor outside the lung. The follow up was excellent being recurrence free for 14 months in spite of the positive surgical margin by the tumor cells. This is a first report  of rare neoplasm, clear cell carcinoma of salivary gland type, presenting as an endotracheal mass.

Relationship between Senior Drivers’ Cognitive and Physical Functions and Urban Driving Behaviors during Behind-the-Wheel Driving Education Sessions with Driving Instructors  [PDF]
Takashi Yonekawa, Takahiro Tanaka, Hirofumi Aoki, Misako Yamagishi, Yuki Yoshihara, Eijiro Takeuchi, Issey Takahashi, Yoshiki Ninomiya, Hitoshi Kanamori, Tatsuya Suzuki, Makoto Inagami
Journal of Transportation Technologies (JTTs) , 2017, DOI: 10.4236/jtts.2017.72011
Abstract: Recently, traffic accidents caused by elderly drivers have been increasing. It is thought that the reasons of accidents are functions such as decline of eyesight, cognition and physical strength caused by aging. In order to assist safe driving for elderly drivers, it is necessary to sufficiently understand any possible relationship of various senior drivers’ cognition, physical strength and driving behavior. In this paper relationship of elderly driver’s cognition, physical strength and driving behaviors were analyzed using the result of driving instructions on urban road by driving school instructors.
In Vivo Evidence of Enhancement of HGF-induced Angiogenesis by Fluvastatin
In VivoYasushi Takeya, Hirofumi Makino, Motokuni Aoki, Takashi Miyake, Kazunari Ozaki, Hiromi Rakugi, Toshio Ogihara and Ryuichi Morishita
The Open Gene Therapy Journal , 2008, DOI: 10.2174/1875037000801010001]
Abstract: Currently, therapeutic angiogenesis using gene transfer of angiogenic growth factors has entered the realm of novel therapy for patients with critical limb ischemia. However, its clinical utility might be enhanced by combination with classical pharmacological approaches. Thus, in this study, we examined adjunctive therapy to enhance the angiogenic effects of gene transfer, with HMG-CoA reductase inhibitors, statins, which have pleiotropic vascular-protective effects. Here, we evaluated the effects of a combination of hepatocyte growth factor (HGF) gene therapy with fluvastatin in a mouse hindlimb ischemia model. Hindlimb ischemia model mice were given a normal diet, high-cholesterol diet (HCD) or HCD with fluvastatin, after intramuscular injection of human HGF plasmid DNA. Intramuscular injection of HGF plasmid into ischemic limbs significantly increased blood flow and capillary density. However, HCD diminished the increase in blood flow and capillary density induced by HGF gene transfer. Administration of fluvastatin significantly attenuated the reduction in blood flow and decrease in capillary density, while it did not change the serum cholesterol level. Overall, these results demonstrated that fluvastatin significantly enhanced the increase in blood flow and capillary density induced by HGF gene transfer in a hindlimb ischemia mouse model with HCD, through a non-cholesterol-lowering effect. Clinical use of fluvastatin might be possible adjunctive therapy to enhance therapeutic angiogenesis.
Multiorbital analysis of the effects of uniaxial and hydrostatic pressure on $T_c$ in the single-layered cuprate superconductors
Hirofumi Sakakibara,Katsuhiro Suzuki,Hidetomo Usui,Kazuhiko Kuroki,Ryotaro Arita,Douglas J. Scalapino,Hideo Aoki
Physics , 2012, DOI: 10.1103/PhysRevB.86.134520
Abstract: The origin of uniaxial and hydrostatic pressure effects on $T_c$ in the single-layered cuprate superconductors is theoretically explored. A two-orbital model, derived from first principles and analyzed with the fluctuation exchange approximation gives axial-dependent pressure coefficients, $\partial T_c/\partial P_a>0$, $\partial T_c/\partial P_c<0$, with a hydrostatic response $\partial T_c/\partial P>0$ for both La214 and Hg1201 cuprates, in qualitative agreement with experiments. Physically, this is shown to come from a unified picture in which higher $T_c$ is achieved with an "orbital distillation", namely, the less the $d_{x^2-y^2}$ main band is hybridized with the $d_{z^2}$ and $4s$ orbitals higher the $T_c$. Some implications for obtaining higher $T_c$ materials are discussed.
First-principles band structure and FLEX approach to the pressure effect on $T_c$ of the cuprate superconductors
Hirofumi Sakakibara,Katsuhiro Suzuki,Hidetomo Usui,Kazuhiko Kuroki,Ryotaro Arita,Douglas J. Scalapino,Hideo Aoki
Physics , 2012, DOI: 10.1088/1742-6596/454/1/012021
Abstract: High-temperature cuprate superconductors have been known to exhibit significant pressure effects. In order to fathom the origin of why and how Tc is affected by pressure, we have recently studied the pressure effects on Tc adoptig a model that contains two cupper d-orbitals derived from first-principles band calculations, where the dz2 orbital is considere on top of the usually considered dx2-y2 orbital. In that paper, we have identified two origins for the Tc enhancement under hydrostatic pressure: (i) while at ambient pressure the smaller the hybridization of other orbital components the higher the Tc, an application of pressure acts to reduce the multiorbital mxing on the Fermi surface, which we call the orbital distillation effects, and (ii) the increase of the band width with pressure also contributes to the enhancement. In the present paper, we further elabolrate the two points. As for point (i), while the reduction of the apical oxygen height under pressure tends to increase the dz2 mixture, hence to lower Tc, here we show that this effect is strongly reduced in bi-layer materials due to the pyramidal coordination of oxygen atoms. As for point (ii), we show that the enhancement of Tc due to the increase in the band width is caused by the effect that the many-body renormalization arising from the self-energy is reduced.
An autopsy case of granulocyte-colony-stimulating-factor-producing extrahepatic bile duct carcinoma
Satoru Matsuyama, Tomonori Shimonishi, Hirofumi Yoshimura, Kensaku Higaki, Kenji Nasu, Mariko Toyooka, Shigehisa Aoki, Keiko Watanabe and Hajime Sugihara
World Journal of Gastroenterology , 2008,
Abstract: A 79-year-old man was referred to this department due to the presence of extrahepatic bile duct carcinoma with a tumor at the left chest wall. The lesion was suspected to be a metastasis of bile duct carcinoma to the left wall, however, computed tomography (CT) revealed no regional lymph node or liver metastases. In addition, cytological and pathological examinations did not show malignancy. At the time of admission, the white blood cell count was 21 460 cells/μL (neutrophils, 18 240 cells/μL) and this elevated to 106 040 before death. In addition, serum granulocyte colony-stimulating factor (G-CSF) was elevated. At 28 d after admission, the patient died. An autopsy showed a poorly differentiated adenocarcinoma with sarcomatous change, which had slightly invaded into the pancreas around the bile duct, and was found in the distal bile duct with multiple metastases to the chest wall, lung, kidney, adrenal body, liver, mesentery, vertebra and mediastinal and para-aortic lymph nodes, without locoregional lymph node and liver metastasis. The cancer cells showed positive immunohistochemical staining for anti-G-CSF antibody. This is believed to be the first report of an extrahepatic bile duct carcinoma that produces G-CSF. Since G-CSF-producing carcinoma and sarcomatous change of the biliary tract leads to poor prognosis, early diagnosis and treatment are needed. When infection is ruled out, the G-CSF in serum should be examined. In addition, examinations such as bone scintigraphy and chest CT should also be considered for distant metastasis.
Page 1 /2200
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.