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Search Results: 1 - 10 of 5555 matches for " Herman Hideyuki Uchida;Hiroyasu Matsui;Osamu Mikami;Toshio Wakabayashi "
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A Single-Feed Planar Antenna for Terrestrial Dtv Reception in Mobile Communication
Herman Hideyuki Uchida;Hiroyasu Matsui;Osamu Mikami;Toshio Wakabayashi
PIER C , 2011, DOI: 10.2528/PIERC11081203
Abstract: Japanese terrestrial broadcasting was completely converted to digital television (DTV) broadcasting on 470--710\,MHz as of July 2011. However, fading phenomenon resulting from standing waves is a factor in quality deterioration in TV and mobile communication technologies. Suppression of this is needed for many kinds of technologies. A broadband single-feed planar antenna composed of two antenna components, a Broadband Planar Monopole Antenna (B-PMA) and a Broadband Planar Slot Antenna (B-PSA), is proposed for reducing deterioration of reception due to the fading across the DTV band. Reflection coefficients and radiation patterns analyzed by the Finite Difference Time Domain (FDTD) method and compared with measured results indicate that the proposed antenna is broadband compared with a conventional antenna studied previously. A field experiment is conducted in the DTV band. The results of the field experiment indicate clearly that the proposed antenna efficiently suppresses fading resulting from standing waves across the band.
Single-Feed Planar Antenna for Suppressing the Change in Received Signal Level Due to Standing Waves in Mobile Communication
Herman Hideyuki Uchida;Hiroyasu Matsui;Osamu Mikami;Toshio Wakabayashi
PIER B , 2011, DOI: 10.2528/PIERB11020311
Abstract: The fading phenomenon resulting from standing waves is a factor in quality deterioration in mobile communication technologies (e.g., cellular phones and television receivers). Suppression of this fading phenomenon is needed for many kinds of technologies. A single-feed planar antenna composed of two antenna components, a Planar Monopole Antenna (PMA) and a Planar Slot Antenna (PSA), is proposed for reducing deterioration of reception due to the fading phenomenon. Reflection coefficient and radiation patterns are analyzed by the Finite Difference Time Domain (FDTD) method and compared with measured results. Results indicate that the proposed antenna has a resonant frequency with functions of the PMA and the PSA. The results of a field experiment at 583.76MHz in the Ultra High Frequency (UHF) band indicate that the proposed antenna efficiently suppresses the fading phenomenon resulting from multipath propagation.
Product Reputation Trend Extraction from Twitter  [PDF]
Aizhan Bizhanova, Osamu Uchida
Social Networking (SN) , 2014, DOI: 10.4236/sn.2014.34024
Abstract:

Micro-blogging today has become a very popular communication tool among the Internet users. Real-time web services such as Twitter allow users to express their opinions and interests, often expressed in the form of short text messages. Many business companies are looking into utilizing these data streams in order to improve their marketing campaigns, refine advertising and better meet their customer needs. In this study, we focus on using Twitter, for the task of extraction product reputation trend. Thus, business could gauge the effectiveness of a recent marketing campaign by aggregating user opinions on Twitter regarding their product. In this paper, we introduce an approach for automatically classifying the sentiment of Twitter messages toward product/brand, using emoticons and by improving pre-processing steps in order to achieve high accuracy.

Improvement of Core Performance by Introduction of Moderators in a Blanket Region of Fast Reactors
Toshio Wakabayashi
Science and Technology of Nuclear Installations , 2013, DOI: 10.1155/2013/879634
Abstract: An application of deuteride moderator for fast reactor cores is proposed for power flattening that can mitigate thermal spikes and alleviate the decrease in breeding ratio, which sometimes occurs when hydrogen moderator is applied as a moderator. Zirconium deuteride is employed in a form of pin arrays at the inner most rows of radial blanket fuel assemblies, which works as a reflector in order to flatten the radial power distribution in the outer core region of MONJU. The power flattening can be utilized to increase core average burn-up by increasing operational time. The core characteristics have been evaluated with a continuous-energy model Monte Carlo code MVP and the JENDL-3.3 cross-section library. The result indicates that the discharged fuel burn-up can be increased by about 7% relative to that of no moderator in the blanket region due to the power flattening when the number of deuteride moderator pins is 61. The core characteristics and core safety such as void reactivity, Doppler coefficient, and reactivity insertion that occurred at dissolution of deuteron were evaluated. It was clear that the serious drawback did not appear from the viewpoints of the core characteristics and core safety. 1. Introduction In order to flatten radial power distribution in fast reactors, ordinary fast reactor cores employ two enrichment zones where outer zone has higher plutonium enrichment. Even in such design the power is dropped at the outer zone of the outer core due to the neutron leakage at the peripheral regions. Zirconium hydride has advantages of high moderation ratio as well as the stability to neutron irradiation as no gas emission occurs at neutron absorption. On the other side, it sometimes induces thermal spikes at the fuel pins adjacent to the moderator zones and reduces breeding ratios due to the large absorption cross section of hydrogen contained even in the fast reactor hard spectrum. However, such features of generating thermal spikes will be useful to increase the power at low power region such as core peripherals if the moderator is appropriately arranged, and it can provide the flattening in power distributions in fast reactors. There are many studies [1–8] for the application of moderator in fast reactors. When the moderator material is mixed with absorber or long-life fission products (LLFPs) in the fast reactor core, it will offer many advantages in core performances such as an increase in control rod worth or transmutation rate of LLFP [1–5]. The most promising moderator applicable to the fast reactor has been considered to be zirconium
Intraductal Papillary Neoplasms of the Bile Duct
Masayuki Ohtsuka,Hiroaki Shimizu,Atsushi Kato,Hideyuki Yoshitomi,Katsunori Furukawa,Toshio Tsuyuguchi,Yuji Sakai,Osamu Yokosuka,Masaru Miyazaki
International Journal of Hepatology , 2014, DOI: 10.1155/2014/459091
Abstract: Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas. IPNBs display a spectrum of premalignant lesion towards invasive cholangiocarcinoma. The most common radiologic findings for IPNB are bile duct dilatation and intraductal masses. The major treatment of IPNB is surgical resection. Ultrasonography, computed tomography, magnetic resonance image, and cholangiography are usually performed to assess tumor location and extension. Cholangioscopy can confirm the histology and assess the extent of the tumor including superficial spreading along the biliary epithelium. However, pathologic diagnosis by preoperative biopsy cannot always reflect the maximum degree of atypia, because IPNBs are often composed of varying degrees of cytoarchitectural atypia. IPNBs are microscopically classified into four epithelial subtypes, such as pancreatobiliary, intestinal, gastric, and oncocytic types. Most cases of IPNB are IPN with high-grade intraepithelial neoplasia or with an associated invasive carcinoma. The histologic types of invasive lesions are either tubular adenocarcinoma or mucinous carcinoma. Although several authors have investigated molecular genetic changes during the development and progression of IPNB, these are still poorly characterized and controversial. 1. Introduction Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors, which is characterized by papillary or villous growth within the bile duct lumen. Formerly, attention has been drawn to biliary tumors with macroscopically visible mucin secretion, which show predominantly papillary growth within the dilated bile duct lumen and secrete a large amount of mucin. These tumors were called by various names, such as mucin-producing cholangiocarcinoma [1–4], mucin-hypersecreting bile duct tumor [5], and intraductal papillary mucinous tumor of the bile duct [6, 7], and were identified as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. On the other hand, biliary intraductal tumors without macroscopically visible mucin secretion are also known, which have a macroscopically recognizable papillary or granular structure but no clinically visible mucin secretion. Since certain morphological features of these tumors, especially intraductal papillary growth pattern, are also similar to those of IPMN of the pancreas, Zen et al. [8] proposed
Prediction and Treatment of Difficult Cases in Colorectal Endoscopic Submucosal Dissection
Yutaka Inada,Naohisa Yoshida,Munehiro Kugai,Kazuhiro Kamada,Kazuhiro Katada,Kazuhiko Uchiyama,Osamu Handa,Tomohisa Takagi,Hideyuki Konishi,Nobuaki Yagi,Yuji Naito,Naoki Wakabayashi,Akio Yanagisawa,Yoshito Itoh
Gastroenterology Research and Practice , 2013, DOI: 10.1155/2013/523084
Abstract: Purpose. The aim of this study was to examine the characteristics of difficult cases and the learning curve in colorectal endoscopic submucosal dissection (ESD). Methods. We studied 518 colorectal tumors treated by ESD. Patients were divided into 2 groups such as the difficult ESD group and non-difficult ESD group in view of procedure time and procedure speed, respectively. The clinical features in each group were analyzed, and we also examined cases with severe fibrosis. Furthermore, we divided all cases into 5 periods according to experience of ESDs and investigated the rates of difficult and perforation cases. Results. In view of both procedure time and procedure speed, there were significant differences about mean tumor size, rates of severe fibrosis and perforation, and en bloc resection rate between the two groups. Severe fibrosis was detected in protruding tumors >40?mm in diameter. With respect to the learning curve, the rate of difficult and perforation cases decreased significantly in the late periods compared to the first period. Conclusions. Large tumor size, high rates of severe fibrosis and perforation, and low rate of en bloc resection are related with difficult ESD cases. The increasing of experiences can decrease the rate of difficult cases and perforation. 1. Introduction In Japan and some other Western and Asian countries, ESD is reported to be an efficient treatment with a high rate of en bloc resection for large colorectal tumors, and ESD is less invasive than laparoscopic colectomy (LAC) [1]. ESD should be performed for tumors that are diagnosed as intramucosal cancer and shallowly invaded submucosal cancer [2, 3]. The number of colorectal ESD has increased gradually with the development of safer strategies and improvements of suitable ESD devices. However, the control of endoscopes and ESD knives are hindered in some colorectal ESD cases because the colon is winding and has many folds. Additionally, restlessness resulting from abdominal fullness and pain is related to prolonged procedure times [4, 5]. It is therefore important to predict difficult cases to prevent complications, including perforation [5, 6]. In this study, we investigated difficult ESD cases with long procedure times or slow procedure speed and examined learning curve of ESD. 2. Patients and Methods A total of 518 tumors in 418 patients who underwent ESD at the Kyoto Prefectural University of Medicine or Nara City Hospital from 2006 to 2013 were analyzed. We examined clinical outcomes for all 518 tumors and divided the tumors into 2 groups such as the difficult
Maximums and minimums of overall survival functions with fixed marginal distributions and transmission of technology
Isao Higuchi,Toshio Mikami
Mathematics , 2008,
Abstract: Title: An unlikely result Authors: T.M. Other Comments: This paper has been withdrawn Abstract: This paper has been withdrawn by the author due to the fact that some of the results turned out to be known.
Effects of metal ions on the activity and stability of peroxidase in Tartary buckwheat shoots  [PDF]
Daisuke Mikami, Hideyuki Kurihara, Koretaro Takahashi, Tatsuro Suzuki, Toshikazu Morishita
Journal of Agricultural Chemistry and Environment (JACEN) , 2013, DOI: 10.4236/jacen.2013.23009
Abstract: This is the first report to purify and characterize POX in shoots of buckwheat species. POX was partially purified from Tartary buckwheat shoots by 48.0 fold with a final yield of 9.07%. During ion-exchange and gel filtration chromatography,only one peak corresponding to POX activity was found. The molecular weight of POX was determined to be 37.5 kDa using gel filtration chromatography. The optimal pH of POX activity was 5.5 (guaiacol, quercetin) and 5.0 (ABTS). The Km of POX activity was 22.3 mM (guaiacol), 6.3 mM (ABTS) and 0.92 mM (quercetin). In contrast, the Km for quercetin in the presence of Fe3+ions was two orders of magnitude less (0.018 mM) than that in its absence. The stability of POX activity was increased in the presence of trivalentmetal ions, even after 186 h in solution. POX activity
was retained by 83.6% and 56.1% in the presence of 1 mMFe3+and Al3+ions, respectively, whereasit was completely inactivated in
their absence. To the best of our knowledge, this is thefirst study to detail the activation and stabilization of POX activity in relation to trivalent metal ions.


Re-Evaluation of the Safety of Laser-Assisted Subepithelial Keratectomy  [PDF]
Yuji Kumano, Yumi Soejima, Shinichiro Numa, Hiroyasu Matsui, Ikuko Zushi, Masahito Shigematsu, Takaaki Matsui, Teruo Nishida
Open Journal of Ophthalmology (OJOph) , 2014, DOI: 10.4236/ojoph.2014.43013
Abstract:

Purpose: Additional analyses of outcomes of laser-assisted subepithelial keratectomy (LASEK) are still necessary to improve the safety of LASEK. Therefore, in our study, outcomes were assessed retrospectively in 561 eyes that underwent LASEK treatment. Methods: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA) and residual spherical equivalent were analyzed at 3 and 6 months postoperatively. We assessed four subgroups based on the degree of preoperative myopia considering mean BSCVA and loss of two or more lines. Results: Mean UCVAs and BSCVAs were obtained at 3 and 6 months postoperatively (1.23/1.35 and 1.23/1.37, respectively). The mean predictability was within ±0.125 diopters. Conversely, the safety indexes were 0.94 and 0.96 respectively, and the efficacy indexes were 0.86 and 0.86 at 3 and 6 months postoperatively, respectively. 8.4% eyes and 5.2% eyes lost two or more lines of BSCVA at 3 and 6 months postoperatively, respectively. The mean BSCVAs of the high or ultra-high groups were significantly lower than those of the low or mild groups both 3 months and 6 months postoperatively. The incidence rates of losing two or more lines of BSCVA in the high or ultra-high myopia groups were significantly greater than in the low or mild groups at 3 months and 6 months postoperatively. Conclusion: LASEK predictably corrected myopia achieving >1.2 in UCVA and BSCVA. However, the safety and efficacy indexes were <1.0, which were related to the loss of two or more lines of BSCVA. Since the incidence rates of losing two or more lines of BSCVA were greater in the high or ultra-high myopia groups, we consider LASEK as more safely performed in patients with low to mild preoperative myopia.

A neural network-based infection screening system that uses vital signs and percutaneous oxygen saturation for rapid screening of patients with influenza  [PDF]
Guanghao Sun, Yukiya Hakozaki, Shigeto Abe, Osamu Takei, Takemi Matsui
Health (Health) , 2013, DOI: 10.4236/health.2013.58A5002
Abstract:

Objective: Influenza is a highly infectious viral disease, which occurs epidemically almost every winter in Japan. Rapid screening of patients with suspected influenza in places of mass gathering is important to delay or prevent transmission of the infection. The aim of this study was to assess the effectiveness of our newly developed infection screening system that employed vital signs and percutaneous oxygen saturation (SpO2) as parameters in a clinical setting. Methods: Since SpO2 accurately reflects respiratory status during influenza virus infection, we upgraded our previous system by adding SpO2 as a new parameter to improve the screening accuracy. This system instantly measures SpO2 and vital signs (i.e., heart rate, respiration rate, and facial temperature), which automatically detects infected individuals via a neural network-based nonlinear discriminant function using these derived parameters. We tested the system on 45 patients with seasonal influenza (35.8℃ < body temperature < 40.0℃, 18-35 years) and 64 normal control subjects (35.0℃ < body temperature < 37.5℃, 18-30 years) at Japan Self-Defense Central Hospital in 2012. Results: The system identified 40/45 patients with influenza and 60/64 normal control subjects, and provided sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of 88.8%, 93.8%, 90.9%, and 92.3%, respectively. By including SpO2 as a screening parameter, we achieved superior sensitivity and NPV compared to that reported in our previous paper (sensitivity = 88%; NPV = 82%). Conclusions: Our results suggest that SpO2 is a

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