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Search Results: 1 - 10 of 14467 matches for " Masahiro Yao "
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Knowledge Sharing and Creating Process in a Social Development Project: Developing a Model for Intra-Project Knowledge Management  [PDF]
Masahiro Oseko
Open Journal of Social Sciences (JSS) , 2017, DOI: 10.4236/jss.2017.510011
Abstract:
This research investigated the sharing, experimenting and creating process of knowledge in a social development project implemented by Dhaka city, Bangladesh with the assistance of Japanese government. Most of the international cooperation organizations such as the World Bank are interested in inter-project knowledge management but less in intra-project knowledge management. These organizations mainly focus on storing and sharing of knowledge centering on their headquarters, but not reach out to each one of their projects. However, knowledge is presented, shared, experimented, and created in the field of each project. Conducting a fieldwork and using qualitative research methods, the author closely observed the knowledge process of the project and found that the knowledge was created through the interaction of optimizing and satisfying, rationalistic plan and incremental plan, universal knowledge and local knowledge, and learning and reflecting. Based on these findings, this paper presents a model of knowledge management in a social development assistance project, which was named “PAR model”, a spiral process model of three phases of Planning, Acting, and Reflecting.
Utility and Limitation of Cumulative Stone Diameter in Predicting Urinary Stone Burden at Flexible Ureteroscopy with Holmium Laser Lithotripsy: A Single-Center Experience
Hiroki Ito, Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Masahiro Yao, Yoshinobu Kubota, Junichi Matsuzaki
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065060
Abstract: Purpose To retrospectively assess the clinical utility in ureteroscopy (URS) planning of cumulative stone diameter (CSD), which does not account for stone width or depth, as a predictor of URS outcome and compare it with stone volume. Materials and Methods Patients with renal stones treated at a single institute by flexible URS were retrospectively evaluated. To assess the clinical utility of CSD, relationships between stone-free (SF) status and stone burden (CSD and volume) were analyzed using the area under the receiver operating characteristics (AUROC) curve. To identify stone number impact on CSD, the AUROC of CSD divided by stone number was evaluated. Correlation coefficients of CSD and stone volume were also calculated for groups by stone number. Results In cases with CSD <20.0 mm, CSD and stone volume revealed equal ability to predict SF status. In cases with CSD ≥20.0 mm, stone volume showed higher predictive ability. The ROC curves for cases with ≥4 stones showed that CSD was less predictive of SF status than stone volume. The correlation coefficients of CSD and stone volume by stone number were 0.922 for 1 stone, 0.900 for 2–3 stones, and 0.661 for ≥4 stones. Conclusions In cases with CSD ≥20.0 mm or ≥4 stones, we should evaluate stone volume for a more predictive stone burden, and pretreatment non-contrast CT seems sufficient. In cases with CSD <20.0 mm or 1–3 stones, CSD was as valid a predictor of preoperative stone burden as stone volume, so preoperative kidney-ureter-bladder (KUB) films may be sufficient.
Nonfunctioning Juxtaglomerular Cell Tumor
Ryoko Sakata,Hiroaki Shimoyamada,Masahiro Yanagisawa,Takayuki Murakami,Kazuhide Makiyama,Noboru Nakaigawa,Yoshiaki Inayama,Kenichi Ohashi,Yoji Nagashima,Masahiro Yao,Yoshinobu Kubota
Case Reports in Pathology , 2013, DOI: 10.1155/2013/973865
Abstract: The juxtaglomerular cell tumor (JGCT) is a rare renal tumor characterized by excessive renin secretion causing intractable hypertension and hypokalemia. However, asymptomatic nonfunctioning JGCT is extremely rare. Here, we report a case of nonfunctioning JGCT in a 31-year-old woman. The patient presented with a left renal tumor without hypertension or hypokalemia. Under a clinical diagnosis of renal cell carcinoma, radical nephrectomy was performed. The tumor was located in the middle portion adjacent to the renal pelvis, measuring 2?cm in size. Pathologically, the tumor was composed of cuboidal cells forming a solid arrangement, immunohistochemically positive for renin. Based on these findings, the tumor was diagnosed as JGCT. In cases with hyperreninism, preoperative diagnosis of JGCT is straightforward but difficult in nonfunctioning case. Generally, JGCT presents a benign biological behavior. Therefore, we should take nonfunctioning JGCT into the differential diagnoses for renal tumors, especially in younger patients to avoid excessive surgery. 1. Introduction Juxtaglomerular cell tumor (JGCT), a neoplasm derived from the juxtaglomerular cell of the kidney, was first described by Robertoson et al. and Kihara et al. [1, 2]. Since then, approximately 100 cases have been reported in the literature. Clinically, this tumor is characterized by hypertension due to excessive renin secretion by tumor cells causing secondary hyperaldosteronism [1–3]. Generally, its preoperative diagnosis is relatively easy, because of typical presence of hypertension concomitant with hypokalemia. However, it is quite difficult in cases of asymptomatic nonfunctioning JGCT [3]. Here, we present a case of nonfunctioning JGCT, which is the fourth case reported so far to the best of our knowledge [4–6]. 2. Case Report A 31-year-old woman was referred to our hospital with a left renal tumor incidentally detected during examination for left-side abdominal pain. She had no history of hypertension, and her blood pressure at presentation was 116/62?mmHg. All the laboratory data, including electrolyte levels, were within normal ranges. Unfortunately, preoperative plasma renin activity was not assayed. Unenhanced computed tomography (CT) revealed solitary well-circumscribed mass lesion measuring 2?cm with fine calcifications in the middle portion adjacent to the renal pelvis of the left kidney. Dynamic-enhanced CT demonstrated that the tumor was not enhanced in the corticomedullary (early) phase but enhanced in the excretory (late) phase (Figure 1). Magnetic resonance image (MRI) showed
Dual-Energy Subtraction X-Ray Digital Tomosynthesis: Basic Physical Evaluation  [PDF]
Tsutomu Gomi, Masahiro Nakajima
Open Journal of Medical Imaging (OJMI) , 2012, DOI: 10.4236/ojmi.2012.23021
Abstract: The present study was performed to determine the potential of applying dual-energy subtraction (DES) digital tomo-synthesis to basic physical evaluations. Volumetric X-ray DES digital tomosysnthesis was used to obtain an image of a detectability phantom (an artificial lesion). The image quality of DES digital tomosynthesis was compared to that of DES radiography. The purpose of this study was to determine enhanced visibility quantified in terms of the contrast- to-noise ratio, figure-of-merit, and root-mean-square error. In the in-focus plane, the image quality is better by DES digital tomosynthesis than by DES radiography. The potential usefulness of DES digital tomosynthesis for evaluating a detectability phantom was demonstrated. Further studies are required to determine the ability of DES digital tomosyn-thesis to quantify the spatial relationships between the artificial lesion components of these devices, as well as to iden- tify lesions with diagnostic consequences.
Multifactorial study of mobile phone dependence in medical students: Relationship to health-related lifestyle, Type A behavior, and depressive state  [PDF]
Masahiro Toda, Satoko Ezoe
Open Journal of Preventive Medicine (OJPM) , 2013, DOI: 10.4236/ojpm.2013.31012
Abstract: We investigated factors contributing to mobile phone dependence. To 139 medical students, we administered a self-reporting questionnaire designed to evaluate mobile phone dependence, health-related lifestyle, patterns of behavior, and depressive state. Multivariate logistic regression analysis revealed that scores for poor health-related lifestyle, Type A behavior pattern, and presence of depression are independently associated with degree of mobile phone dependency. These findings suggest that persons with an unhealthy lifestyle, Type A behavior traits, or depression might benefit from mobile phone use guidance.
Relationships of loneliness and mobile phone dependence with Internet addiction in Japanese medical students  [PDF]
Satoko Ezoe, Masahiro Toda
Open Journal of Preventive Medicine (OJPM) , 2013, DOI: 10.4236/ojpm.2013.36055
Abstract: We investigated factors contributing to Internet addiction in 105 Japanese medical students. The subjects were administered by a self-reporting questionnaire designed to evaluate demographic factors, Internet addiction, loneliness, health-related lifestyle factors, depressive state, patterns of behavior, and mobile phone dependence. Results of multivariate logistic regression analysis indicated that loneliness and mobile phone dependence were positively related to degree of addiction. Our findings suggest that Internet addiction is associated with loneliness and mobile phone dependence in Japanese students.
Object-Spatial Imagery Types of Japanese College Students  [PDF]
Masahiro Kawahara, Kazuo Matsuoka
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.43024
Abstract:

This study investigated the object-spatial imagery types found among Japanese college students. First, we examined the descriptive statistics of the Japanese version of the Object-Spatial Imagery Questionnaire object-spatial imagery scales, which measure respondents’ tendencies with respect to object-spatial imagery types. Although the means of these subscales were lower than those of the original versions, the raw score distributions and gender differences were similar to those obtained using the original version. Additionally, we compared imagery types among students in seven different academic departments. Specifically, the results showed specific patterns of imagery type among students in each department, indicating that the object-spatial imagery type model is applicable to Japanese college students and that individual imagery type data would be helpful for career guidance.

Influence of Wettability and Mechanical Properties on Tribological Performance of DLC Coatings under Water Lubrication  [PDF]
Chaoqun Zhang, Masahiro Fujii
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2015, DOI: 10.4236/jsemat.2015.53013
Abstract: DLC coatings are currently used in a wide variety of industrial fields because of their outstanding properties such as high hardness, high wear resistance, low friction and so on under oil lubrication as well as no lubrication. In order to evaluate the tribological performance of DLC coatings under water lubrication, eight types of DLC coatings were evaluated by water-lubricated sliding tests at sliding velocities of 0.02 m/s and 0.1 m/s. The different DLC coating types comprised both hydrogenated and hydrogen-free DLC films that were deposited using different techniques: amorphous hydrogenated DLC (a-C:H), that doped with tungsten (a-C:H:W), that doped with silicon (a-C:H:Si) and hydrogen-free DLC (ta-C). DLC coatings showed low friction coefficient and excellent wear resistance. Friction coefficient and wear rate decreased with increasing sliding velocity. The effect of surface wettability and mechanical properties on tribological characteristics was investigated. Friction coefficient decreased as the contact angle increased. Hydrogen-free DLC coating with the highest hardness showed the highest friction and a larger wear rate. Furthermore, DLC coatings deposited with interlayer showed longer lifetimes.
Tribological Behavior of Thermally Sprayed WC Coatings under Water Lubrication  [PDF]
Chaoqun Zhang, Masahiro Fujii
Materials Sciences and Applications (MSA) , 2016, DOI: 10.4236/msa.2016.79045
Abstract: Thermally sprayed coatings have been used in various fields of industry for enhancing surface characteristics of materials and extending their service life. The contact surface of some mechanical equipment such as the fine pulverization equipment which is used in the woody biomass production process is required to have wear resistance in the water environment. Thermally sprayed coatings would be a good candidate to improve surface wear resistance under water lubrication. The objective of this study was to evaluate the tribological performance of thermally sprayed coatings under water lubrication. Thermally sprayed coatings which were classified into WC, WB and Ni spraying of three categories were compared with water-lubricated sliding test at a sliding velocity of 0.02 m/s and mean pressure of p0 = 10 MPa with a ring-on-disk apparatus. Thermally sprayed coatings showed comparatively high friction coefficient and well wear resistance under water lubrication. WC contained coatings showed better wear resistance than WB and Ni coatings. Thermally sprayed coatings showed obviously different mechanical properties and tribological behaviors, and the effect of wettability and hardness on tribological characteristics was discussed under water lubrication. Friction coefficient increased as the surface contact angle of thermally sprayed coatings increased. The wear rate decreased as the surface hardness of thermally sprayed coatings increased. Wear resistance of thermally sprayed coatings was excellent under water lubrication. WC contained coatings showed lower wear rate than WB and Ni coatings. WC-14CoCr coating showed the lowest wear rate.
An Improved Open-Top Chamber with Solar-Heated Double Funnels That Can Adapt to All Wind Directions for Simulating Future Global Warming Conditions in Rice Paddy Fields  [PDF]
Tomio Terao, Masahiro Chiba
Agricultural Sciences (AS) , 2016, DOI: 10.4236/as.2016.710067
Abstract:
An Open-Top Chamber with Solar-heated Double Funnels (OTC-SDF2) that uses solar energy as a heating source was developed in this study. Two air entry/exit funnels were connected to the OTC via flat tunnels through which air was warmed by solar radiation. The new apparatus increased the air temperature by approximately 1°C throughout the chamber when more than half the energy of full sunlight was supplied. Although air flow occurs in only two directions, a nearly constant temperature increase was observed for each wind direction. This increase in temperature was stable for 1 mˉs to 4 mˉs wind speeds in every direction. This degree of warming may be adequate for screening high-temperature tolerant plants from medium to weak cultivars. The OTC-SDF2 has the potential to provide moderately high-temperature treatments for screening various cultivars/strains and may be used to evaluate easy, low-cost cropping methods associated with high-temperature stresses.
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