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Search Results: 1 - 10 of 4087 matches for " Toshio Nakamura "
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Stochastic Modeling of Database Backup Policy for a Computer System  [PDF]
Syouji Nakamura, Xufeng Zhao, Toshio Nakagawa
Journal of Software Engineering and Applications (JSEA) , 2013, DOI: 10.4236/jsea.2013.62009
Abstract:

As the computer system has developed much in this highly information-oriented society, database security has become a very important problem and its backup strategies need to be made more efficiently and safety. The image copy method has been used as the most simple and dependable recovery mechanism for media failure. However, this method spends high overhead costs for massive data transmission and much processing time in the normal operation of the database. To cover such weak points, incremental and full backup methods are adopted before updated trucks reach a predetermined level. Moreover, when the number of full backup files exceeded a predetermined level, we stop incremental and full backups and switch it to the image copy. This paper applies cumulative damage model to backup of files in a database system, by putting damage shock by update, failure shock by database failure and damage by dumped files, and considers the tradeoff among overhead costs of image copy and incremental, full backup methods, and discusses analytically an optimal policy for the image copy backup interval. Finally, numerical examples are given in the case of Poisson process and exponential distributions.

Probability Distributions Achieving the Equilibrium of an AND-OR Tree under Directional Algorithms
Toshio Suzuki,Ryota Nakamura
Lecture Notes in Engineering and Computer Science , 2012,
Abstract:
The Eigen Distribution of an AND-OR Tree under Directional Algorithms
Toshio Suzuki,Ryota Nakamura
IAENG International Journal of Applied Mathematics , 2012,
Abstract:
The quaternary geological history of the Santa Catarina Southeastern Region (Brazil)
CARUSO JR., FRANCISCO;SUGUIO, KENITIRO;NAKAMURA, TOSHIO;
Anais da Academia Brasileira de Ciências , 2000, DOI: 10.1590/S0001-37652000000200011
Abstract: this paper supply subsidies for quaternary geological reconstruction of the southeastern state of santa catarina coast in brazil, being based on detailed geological mapping supported by a series of drilling data, which allowed to establish a stratigraphical hierarchy of the sedimentary deposits. among the mapped geological units stand out the extensive pleistocene shallow marine sandy sediments, which are commonly referred as a barrier island - lagoonal depositional system. a drilling campaign done in the domain permitted the sampling of material for 14c datings, and the obtained data confirmed some previously assumed ages. the sequence of events, that originated the holocene deposits, has been also reconstructed through drilling and 14c dating of the collected peat and shell samples. finally, the main characteristics of the most promising mineral prospect of the area, represented by voluminous calcareous shell deposits associated with holocene sediments, are also presented.
The quaternary geological history of the Santa Catarina Southeastern Region (Brazil)
CARUSO JR. FRANCISCO,SUGUIO KENITIRO,NAKAMURA TOSHIO
Anais da Academia Brasileira de Ciências , 2000,
Abstract: This paper supply subsidies for Quaternary geological reconstruction of the southeastern State of Santa Catarina coast in Brazil, being based on detailed geological mapping supported by a series of drilling data, which allowed to establish a stratigraphical hierarchy of the sedimentary deposits. Among the mapped geological units stand out the extensive Pleistocene shallow marine sandy sediments, which are commonly referred as a barrier island - lagoonal depositional system. A drilling campaign done in the domain permitted the sampling of material for 14C datings, and the obtained data confirmed some previously assumed ages. The sequence of events, that originated the Holocene deposits, has been also reconstructed through drilling and 14C dating of the collected peat and shell samples. Finally, the main characteristics of the most promising mineral prospect of the area, represented by voluminous calcareous shell deposits associated with Holocene sediments, are also presented.
Synchrotron Refraction Enhanced Tomography of an Intact Common Marmoset (Callithrix jacchus)  [PDF]
Toshihiro Sera, Hideo Yokota, SakikoS. Nakamura, Kentaro Uesugi, Masato Hoshino, Naoto Yagi, Toshio Ito, Keigo Hikishima, Hirotaka James Okano
Open Journal of Radiology (OJRad) , 2011, DOI: 10.4236/ojrad.2011.12005
Abstract: The common marmoset (Callithrix jacchus), a small new world monkey species, has been widely used in various scientific fields. It is necessary to understand connections between specific genotypes, their structure, and function; however, an anatomical atlas of the entire body of the common marmoset has not yet been reported. In addition to conventional absorption, refraction enhanced computed tomography (CT) based on synchrotron radiation can increase the contrast of boundaries between small absorption differences. In this study, to examine the potential of creating an anatomical atlas of the whole body of the common marmoset non-invasively, we visualized an intact marmoset using synchrotron refraction enhanced CT. The cryogenic marmoset was scanned using the medical imaging beamline at the SPring-8 synchrotron radiation research facility in JAPAN. The trabecular structure, articular cartilage, cruciate ligament in the knee joint, and small airways (diameter: > 400 μm) was clearly identified with 50 μm voxel size and 37 keV x-ray energy. The structure of the heart and branching vessels in the kidneys and liver were also identified without contrast agents, and the anatomical structure of the brain was slightly visible. These results show that synchrotron refraction enhanced CT is useful for creating an anatomical atlas non-invasively, and further studies are planned that will combine refraction enhanced CT and other imaging techniques to analyse the morphology and create a complete atlas of the whole body of the common marmoset.
Intrisic Dispersion of Correlations among Ep, Lp, and Eiso of Gamma Ray Bursts depends on the quality of Data Set
Ryo Tsutsui,Takashi Nakamura,Daisuke Yonetoku,Toshio Murakami,Keitaro Takahashi
Physics , 2010,
Abstract: We reconsider correlations among the spectral peak energy ($E_p$), 1-second peak luminosity ($L_p$) and isotropic energy (\Eiso), using the database constructed by \citet{yonetoku10} which consists of 109 Gamma-Ray Bursts (GRBs) whose redshifts are known and $E_p$, $L_p$ and \Eiso are well determined. We divide the events into two groups by their data quality. One (gold data set) consists of GRBs with peak energies determined by the Band model with four free parameters. On the other hand, GRBs in the other group (bronze data set) have relatively poor energy spectra so that their peak energies were determined by the Band model with fixed spectral index (i.e. three free parameters) or by the Cut-off power law (CPL) model with three free parameters. Using only the gold data set we found the intrinsic dispersion in $\log L_p$ ($=\sigma_{\rm int}$) is 0.13 and 0.22 for \tsutsui correlation ($T_L \equiv E_{\rm iso}/L_p$) and \yonetoku correlation, respectively. We also find that GRBs in the bronze data set have systematically larger $E_p$ than expected by the correlations constructed with the gold data set. This means that the intrinsic dispersion of correlations among $E_p$, $L_p$, and \Eiso of GRBs depends on the quality of data set. At present, using \tsutsui correlation with gold data set, we would be able to determine the luminosity distance with $\sim 16%$ error, which might be useful to determine the nature of the dark energy at high redshift $z > 3$.
Emergent Completion Pneumonectomy for Postoperative Hemorrhage from Rupture of the Infected Pulmonary Artery in Lung Cancer Surgery
Takanori Ayabe,Tetsuya Shimizu,Masaki Tomita,Mitsuhiro Yano,Kunihide Nakamura,Toshio Onitsuka
Case Reports in Surgery , 2011, DOI: 10.1155/2011/902062
Abstract: Completion pneumonectomy (CP) is one of the most difficult procedures and known to be associated with a high morbidity and mortality. A 74-year-old male underwent a left upper lobectomy for pulmonary adenocarcinoma (T3N0M0); six days later after the surgery, he had a sudden postoperative intrathoracic excessive hemorrhage with shock. Emergent redo thoracotomy was performed to treat the bleeding from the ablated interlobar pulmonary artery by suturing with prolene. However, 3 days later after the second operation, he had the second intrathoracic bleeding. Emergent CP was performed with cardiopulmonary bypass by anterior transpericarsial approach via a median sternotomy. The hemorrhage was caused by a rupture of the proximal fragile and infected pulmonary artery. We performed omentopexy for the infected intrathoracic cavity and for covering of the divided main bronchial stump. We had a rare experience of two times of postoperative life-threatening hemorrhage from rupture of the infected pulmonary artery after left upper lobectomy. Emergent CP as salvage surgery should have an advantage in control of infected proximal pulmonary arterial hemorrhage. We should take care of tearing off of adventitia of pulmonary artery in lobectomy because of a possibility of postoperative hemorrhage under a fragility of the injured pulmonary artery with infection.
Extrarenal multiorgan metastases of collecting duct carcinoma of the kidney: A case series
Hisao Nakamura, Yasuyuki Kuirhara, Kazuhiko Matsushita, Akehide Sakai, Toshio Yamaguchi, Yasuo Nakajima
Journal of Medical Case Reports , 2008, DOI: 10.1186/1752-1947-2-304
Abstract: We present two case reports of multiorgan metastases of collecting duct carcinoma that were autopsy confirmed. The first case was a 55-year-old man who presented with fever and abdominal pain. Abdominal computed tomography showed enlargement of the right kidney. Pyelonephritis was considered on the basis of laboratory test results and imaging findings. However, multiple cavitary lesions were found on routine chest radiography. These lesions were biopsied, resulting in a histological diagnosis of metastatic adenocarcinoma. A renal tumor was considered. Transitional cell carcinoma was suspected, which proved to be misdiagnosed and chemotherapy was given accordingly. However, this was not effective and the patient died after 2 months. Autopsy demonstrated the primary tumor to be collecting duct carcinoma, with metastases to lung, liver, spleen, bone marrow, right adrenal gland, and para-aortic lymph node. Computed tomography done while the patient was alive detected lung, liver, and para-aortic lymph node metastases. The second case was a 77-year-old man who presented with fever. Pyelonephritis was considered on the basis of the laboratory test results and imaging findings. Antibiotic therapy improved his symptoms and laboratory indicators of inflammation. One year later, he developed backache. Computed tomography revealed a progressively enlarging right renal lesion, multiple liver masses, enlargement of the para-aortic lymph nodes, and multiple osteoblastic and osteoclastic lesions. A renal tumor with multiple metastases was diagnosed. Chemotherapy was given without effect, and the patient died of cardiac failure 1 year later. Autopsy revealed a primary tumor of collecting duct carcinoma with metastases to the liver, right adrenal gland, right upper ureter, bone marrow, para-aortic and mediastinal lymph nodes, and bone.We present the radiological findings of lung, liver, lymph node, and bone metastases in two patients with collecting duct carcinoma.Collecting duct ca
A high-resolution environmental change record since 19 cal ka BP in Pumoyum Co, southern Tibet
XinMiao Lü,LiPing Zhu,Mitsugu Nishimura,Yoshimune Morita,Takahiro Watanabe,Toshio Nakamura,Yong Wang
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4656-z
Abstract: A 380-cm-long sediment core was acquired from the deep water area of Pumoyum Co, southern Tibet. Twenty-five plant residue samples were selected, and organic carbon stable isotopes were obtained using the AMS 14C chronological method. The 14C age and carbon reservoir effect were calibrated with surface sedimentation rate measurements using 210Pb dating. Results showed that the core sediment deposited over 19 cal ka BP. Based on a multi-proxy analysis of TOC and IC contents, grain size and pollen assemblage data, the palaeoclimatic evolution of Pumoyum Co was reconstructed since the last glacial. Pumoyum Co was a shallow lake prior to 16.2 cal ka BP; although the glacier around the lake began to melt due to increasing temperatures, climate was still cold and dry. In the interval of 16.2–11.8 cal ka BP, the sedimentary environment fluctuated drastically and frequently. Two cold-events occurred at 14.2 and 11.8 cal ka BP, and these may correspond to the Older Dryas and the Younger Dryas events, respectively. After 11.8 cal ka BP, Pumoyun Co developed into the deep lake as it is now. The lake water temperature was relatively lower at that time because of influx of cold water from glacial meltwater entering the lake. As a result, the multi-proxy indicators showed no sign of warm conditions. Comparisons between the sedimentary record of Pumoyum Co with that of other lakes of the same age in southern Tibet indicate a warmer climate following the last deglaciation influenced the southeastern Tibetan Plateau. These results imply that the southwest Asian monsoon gradually became stronger since the deglaciation during its expansion to the inner plateau. The glacial-supplied water of the lake responded sensitively to cold-events. The entire southern Tibet region was dominantly influenced climatically by the southwest Asian monsoon during the Holocene.
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