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Toshiba (Japan)

companyTokyo, Japan

Research output, citation impact, and the most-cited recent papers from Toshiba (Japan) (Japan). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
27.5K
Citations
1.1M
h-index
278
i10-index
25.3K
Also known as
Toshiba (Japan)東芝

Top-cited papers from Toshiba (Japan)

Stent-Retriever Thrombectomy after Intravenous t-PA vs. t-PA Alone in Stroke
Jeffrey L. Saver, Mayank Goyal, Alain Bonafé, Hans‐Christoph Diener +4 more
2015· New England Journal of Medicine5.1Kdoi:10.1056/nejmoa1415061

BACKGROUND: Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addition to intravenous t-PA, increases reperfusion rates and may improve long-term functional outcome. METHODS: We randomly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone (control group) or to undergo endovascular thrombectomy with the use of a stent retriever within 6 hours after symptom onset (intervention group). Patients had confirmed occlusions in the proximal anterior intracranial circulation and an absence of large ischemic-core lesions. The primary outcome was the severity of global disability at 90 days, as assessed by means of the modified Rankin scale (with scores ranging from 0 [no symptoms] to 6 [death]). RESULTS: The study was stopped early because of efficacy. At 39 centers, 196 patients underwent randomization (98 patients in each group). In the intervention group, the median time from qualifying imaging to groin puncture was 57 minutes, and the rate of substantial reperfusion at the end of the procedure was 88%. Thrombectomy with the stent retriever plus intravenous t-PA reduced disability at 90 days over the entire range of scores on the modified Rankin scale (P<0.001). The rate of functional independence (modified Rankin scale score, 0 to 2) was higher in the intervention group than in the control group (60% vs. 35%, P<0.001). There were no significant between-group differences in 90-day mortality (9% vs. 12%, P=0.50) or symptomatic intracranial hemorrhage (0% vs. 3%, P=0.12). CONCLUSIONS: In patients receiving intravenous t-PA for acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, thrombectomy with a stent retriever within 6 hours after onset improved functional outcomes at 90 days. (Funded by Covidien; SWIFT PRIME ClinicalTrials.gov number, NCT01657461.).

Alpha-power law MOSFET model and its applications to CMOS inverter delay and other formulas
T. Sakurai, A. Richard Newton
1990· IEEE Journal of Solid-State Circuits1.7Kdoi:10.1109/4.52187

An alpha -power-law MOS model that includes the carrier velocity saturation effect, which becomes prominent in short-channel MOSFETs, is introduced. The model is an extension of Shockley's square-law MOS model in the saturation region. Since the model is simple, it can be used to handle MOSFET circuits analytically and can predict the circuit behavior in the submicrometer region. Using the model, closed-form expressions for the delay, short-circuit power, and transition voltage of CMOS inverters are derived. The delay expression includes input waveform slope effects and parasitic drain/source resistance effects and can be used in simulation and/or optimization CAD tools. It is found that the CMOS inverter delay becomes less sensitive to the input waveform slope and that short-circuit dissipation increases as the carrier velocity saturation effect in short-channel MOSFETs gets more severe.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

On the universality of inversion layer mobility in Si MOSFET's: Part I-effects of substrate impurity concentration
S. Takagi, Akira Toriumi, M. Iwase, H. Tango
1994· IEEE Transactions on Electron Devices1.5Kdoi:10.1109/16.337449

This paper reports the studies of the inversion layer mobility in n- and p-channel Si MOSFET's with a wide range of substrate impurity concentrations (10/sup 15/ to 10/sup 18/ cm/sup -3/). The validity and limitations of the universal relationship between the inversion layer mobility and the effective normal field (E/sub eff/) are examined. It is found that the universality of both the electron and hole mobilities does hold up to 10/sup 18/ cm/sup -3/. The E/sub eff/ dependences of the universal curves are observed to differ between electrons and holes, particularly at lower temperatures. This result means a different influence of surface roughness scattering on the electron and hole transports. On substrates with higher impurity concentrations, the electron and hole mobilities significantly deviate from the universal curves at lower surface carrier concentrations because of Coulomb scattering by the substrate impurity. Also, the deviation caused by the charged centers at the Si/SiO/sub 2/ interface is observed in the mobility of MOSFET's degraded by Fowler-Nordheim electron injection.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Definitions for a common standard for 2D speckle tracking echocardiography: consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging
Jens‐Uwe Voigt, Gianni Pedrizzetti, Peter Lysyansky, Thomas H. Marwick +4 more
2014· European Heart Journal - Cardiovascular Imaging1.3Kdoi:10.1093/ehjci/jeu184

Recognizing the critical need for standardization in strain imaging, in 2010, the European Association of Echocardiography (now the European Association of Cardiovascular Imaging, EACVI) and the American Society of Echocardiography (ASE) invited technical representatives from all interested vendors to participate in a concerted effort to reduce intervendor variability of strain measurement. As an initial product of the work of the EACVI/ASE/Industry initiative to standardize deformation imaging, we prepared this technical document which is intended to provide definitions, names, abbreviations, formulas, and procedures for calculation of physical quantities derived from speckle tracking echocardiography and thus create a common standard.

Field test of quantum key distribution in the Tokyo QKD Network
M. Sasaki, Mikio Fujiwara, Hirokazu Ishizuka, Werner Klaus +4 more
2011· Optics Express1.2Kdoi:10.1364/oe.19.010387

A secure communication network with quantum key distribution in a metropolitan area is reported. Six different QKD systems are integrated into a mesh-type network. GHz-clocked QKD links enable us to demonstrate the world-first secure TV conferencing over a distance of 45km. The network includes a commercial QKD product for long-term stable operation, and application interface to secure mobile phones. Detection of an eavesdropper, rerouting into a secure path, and key relay via trusted nodes are demonstrated in this network.

Semantic texton forests for image categorization and segmentation
Jamie Shotton, Matthew Johnson, Roberto Cipolla
20081.0Kdoi:10.1109/cvpr.2008.4587503

We propose semantic texton forests, efficient and powerful new low-level features. These are ensembles of decision trees that act directly on image pixels, and therefore do not need the expensive computation of filter-bank responses or local descriptors. They are extremely fast to both train and test, especially compared with k-means clustering and nearest-neighbor assignment of feature descriptors. The nodes in the trees provide (i) an implicit hierarchical clustering into semantic textons, and (ii) an explicit local classification estimate. Our second contribution, the bag of semantic textons, combines a histogram of semantic textons over an image region with a region prior category distribution. The bag of semantic textons is computed over the whole image for categorization, and over local rectangular regions for segmentation. Including both histogram and region prior allows our segmentation algorithm to exploit both textural and semantic context. Our third contribution is an image-level prior for segmentation that emphasizes those categories that the automatic categorization believes to be present. We evaluate on two datasets including the very challenging VOC 2007 segmentation dataset. Our results significantly advance the state-of-the-art in segmentation accuracy, and furthermore, our use of efficient decision forests gives at least a five-fold increase in execution speed.

A precise and fast temperature mapping using water proton chemical shift
Yasutoshi Ishihara, Arturo Calderón, Hidehiro Watanabe, Kazuya Okamoto +3 more
1995· Magnetic Resonance in Medicine1.0Kdoi:10.1002/mrm.1910340606

A new temperature measurement procedure using phase mapping was developed that makes use of the temperature dependence of the water proton chemical shift. Highly accurate and fast measurements were obtained during phantom and in vivo experiments. In the pure water phantom experiments, an accuracy of more than +/- 0.5 degrees C was obtained within a few seconds/slice using a field echo pulse sequence (TR/TE = 115/13 ms, matrix = 128 x 128, number of slices = 5). The temperature dependence of the water proton chemical shift was found to be almost the same for different materials with a chemical composition similar to living tissues (water, glucide, protein). Using this method, the temperature change inside a cat's brain was obtained with an accuracy of more than +/- 1 degree C and an in-plane resolution of 0.6 x 0.6 mm. The temperature measurement error was affected by several factors in the living system (B0 shifts caused by position shifts of the sample, blood flow, etc.), the position shift effect being the most serious.

Development of a Digital Image Database for Chest Radiographs With and Without a Lung Nodule
Junji Shiraishi, Shigehiko Katsuragawa, J Ikezoe, Tsuneo Matsumoto +4 more
2000· American Journal of Roentgenology1.0Kdoi:10.2214/ajr.174.1.1740071

OBJECTIVE: We developed a digital image database (www.macnet.or.jp/jsrt2/cdrom_nodules.html ) of 247 chest radiographs with and without a lung nodule. The aim of this study was to investigate the characteristics of image databases for potential use in various digital image research projects. Radiologists' detection of solitary pulmonary nodules included in the database was evaluated using a receiver operating characteristic (ROC) analysis. MATERIALS AND METHODS: One hundred and fifty-four conventional chest radiographs with a lung nodule and 93 radiographs without a nodule were selected from 14 medical centers and were digitized by a laser digitizer with a 2048 x 2048 matrix size (0.175-mm pixels) and a 12-bit gray scale. Lung nodule images were classified into five groups according to the degrees of subtlety shown. The observations of 20 participating radiologists were subjected to ROC analysis for detecting solitary pulmonary nodules. Experimental results (areas under the curve, Az) obtained from observer studies were used for characterization of five groups of lung nodules with different degrees of subtlety. RESULTS: ROC analysis showed that the database included a wide range of various nodules yielding Az values from 0.574 to 0.991 for the five categories of cases for different degrees of subtlety. CONCLUSION: This database can be useful for many purposes, including research, education, quality assurance, and other demonstrations.

High WSS or Low WSS? Complex Interactions of Hemodynamics with Intracranial Aneurysm Initiation, Growth, and Rupture: Toward a Unifying Hypothesis
Hui Meng, Vincent M. Tutino, J. Xiang, Adnan H. Siddiqui
2013· American Journal of Neuroradiology942doi:10.3174/ajnr.a3558

SUMMARY: Increasing detection of unruptured intracranial aneurysms, catastrophic outcomes from subarachnoid hemorrhage, and risks and cost of treatment necessitate defining objective predictive parameters of aneurysm rupture risk. Image-based computational fluid dynamics models have suggested associations between hemodynamics and intracranial aneurysm rupture, albeit with conflicting findings regarding wall shear stress. We propose that the "high-versus-low wall shear stress" controversy is a manifestation of the complexity of aneurysm pathophysiology, and both high and low wall shear stress can drive intracranial aneurysm growth and rupture. Low wall shear stress and high oscillatory shear index trigger an inflammatory-cell-mediated pathway, which could be associated with the growth and rupture of large, atherosclerotic aneurysm phenotypes, while high wall shear stress combined with a positive wall shear stress gradient trigger a mural-cell-mediated pathway, which could be associated with the growth and rupture of small or secondary bleb aneurysm phenotypes. This hypothesis correlates disparate intracranial aneurysm pathophysiology with the results of computational fluid dynamics in search of more reliable risk predictors.

Japanese Evaluated Nuclear Data Library Version 3 Revision-2: JENDL-3.2.
Tsuneo NAKAGAWA, Keiichi SHIBATA, Satoshi Chiba, Tokio Fukahori +4 more
1995· Journal of Nuclear Science and Technology905doi:10.3327/jnst.32.1259

The revision work of JENDL-3 has been made by considering feedback information of various benchmark tests. The main revised quantities are the resonance parameters, capture and inelastic scattering cross sections, and fission spectra of main actinide nuclides, the total and inelastic scattering cross sections of structural materials, the resonance parameters the capture and inelastic scattering cross sections of fission products, and the γr-ray production data. The revised data were released as JENDL-3.2 in June 1994. The preliminary benchmark tests indicate that JENDL-3.2 predicts various reactor characteristics more successfully than the previous version of JENDL-3.1.

A CMOS bandgap reference circuit with sub-1-V operation
H. Banba, H. Shiga, Akira Umezawa, T. Miyaba +3 more
1999· IEEE Journal of Solid-State Circuits883doi:10.1109/4.760378

This paper proposes a CMOS bandgap reference (BGR) circuit, which can successfully operate with sub-1-V supply, In the conventional BGR circuit, the output voltage V/sub ref/ is the sum of the built-in voltage of the diode V/sub f/ and the thermal voltage V/sub T/ of kT/q multiplied by a constant. Therefore, V/sub ref/ is about 1.25 V, which limits a low supply-voltage operation below 1 V. Conversely, in the proposed BGR circuit, V/sub ref/ has been converted from the sum of two currents; one is proportional to V/sub f/ and the other is proportional to V/sub T/. An experimental BGR circuit, which is simply composed of a CMOS op-amp, diodes, and resistors, has been fabricated in a conventional 0.4-/spl mu/m flash memory process. Measured V/sub ref/ is 518/spl plusmn/15 mV (3/spl sigma/) for 23 samples on the same wafer at 27-125/spl deg/C.

Direct power control of PWM converter without power-source voltage sensors
Toshihiko Noguchi, H. Tomiki, Seiji Kondo, Isao Takahashi
1998· IEEE Transactions on Industry Applications823doi:10.1109/28.673716

This paper proposes a novel control strategy of a pulsewidth modulation (PWM) converter with no power-source voltage sensors. The strategy has two main features to improve a total power factor and efficiency, taking harmonic components into account without detecting the voltage waveforms. One feature is a direct instantaneous power control technique for the converter, which has been developed to control the instantaneous active and reactive power directly by selecting the optimum switching state of the converter. The other feature is an estimation technique of the power-source voltages, which can be performed by calculating the active and reactive power for each switching state of the converter from the line currents. A digital-signal-processor-based experimental system was developed, and experimental tests were conducted to examine the controllability. As a result, it was confirmed that the total power factor and efficiency were more than 97% and 93% over the load power range from 200 to 1400 W, respectively. These results have proven the excellent performance of the proposed system.

5G-Enabled Tactile Internet
Meryem Simsek, Adnan Aijaz, Mischa Döhler, Joachim Sachs +1 more
2016· IEEE Journal on Selected Areas in Communications767doi:10.1109/jsac.2016.2525398

The long-term ambition of the Tactile Internet is to enable a democratization of skill, and how it is being delivered globally. An integral part of this is to be able to transmit touch in perceived real-time, which is enabled by suitable robotics and haptics equipment at the edges, along with an unprecedented communications network. The fifth generation (5G) mobile communications systems will underpin this emerging Internet at the wireless edge. This paper presents the most important technology concepts, which lay at the intersection of the larger Tactile Internet and the emerging 5G systems. The paper outlines the key technical requirements and architectural approaches for the Tactile Internet, pertaining to wireless access protocols, radio resource management aspects, next generation core networking capabilities, edge-cloud, and edge-AI capabilities. The paper also highlights the economic impact of the Tactile Internet as well as a major shift in business models for the traditional telecommunications ecosystem.

Practical challenges in quantum key distribution
Eleni Diamanti, Hoi-Kwong Lo, Bing Qi, Zhiliang Yuan
2016· npj Quantum Information697doi:10.1038/npjqi.2016.25

Abstract Quantum key distribution (QKD) promises unconditional security in data communication and is currently being deployed in commercial applications. Nonetheless, before QKD can be widely adopted, it faces a number of important challenges such as secret key rate, distance, size, cost and practical security. Here, we survey those key challenges and the approaches that are currently being taken to address them.

Development of a New Type Fault Locator Using the One-Terminal Voltage and Current Data
Toshio Takagi, Y. Yamakoshi, M. Yamaura, R. Kondow +1 more
1982· IEEE Transactions on Power Apparatus and Systems628doi:10.1109/tpas.1982.317615

A new type fault locator has been developed, that calculates the reactance of a faulty line, with a micro-processor, using the one-terminal voltage and current data of the transmission line. Errors caused by various factors such as load flow, fault resistance, and the unsymmetrical arrangement of the transmission line, are automatically corrected. The equipment is now under field test, and during the nine months of the field test, the equipment has operated satisfactorily.

A practical method for position-dependent Compton-scatter correction in single photon emission CT
K. Ogawa, Yasuo Harata, T. Ichihara, Atsushi Kubo +1 more
1991· IEEE Transactions on Medical Imaging616doi:10.1109/42.97591

A new method is proposed to subtract the count of scattered photons from that acquired with a photopeak window at each pixel in each planar image of single-photon emission computed tomography (SPECT). The subtraction is carried out using two sets of data: one set is acquired with a main window centered at photopeak energy and the other is acquired with two subwindows on both sides of the main window. The scattered photons included in the main window are estimated from the counts acquired with the subwindows and then they are subtracted from the count acquired with the main windows. Since the subtraction is performed at each pixel in each planar image, the proposed method has the potential to be more precise than conventional methods. For three different activity distributions in cylinder phantoms, simulation tests gave good agreement between the activity distributions reconstructed from unscattered photons and those from the corrected data.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Smart Grid Privacy via Anonymization of Smart Metering Data
Costas Efthymiou, Georgios Kalogridis
2010609doi:10.1109/smartgrid.2010.5622050

The security and privacy of future smart grid and smart metering networks is important to their rollout and eventual acceptance by the public: research in this area is ongoing and smart meter users will need to be reassured that their data is secure. This paper describes a method for securely anonymizing frequent (for example, every few minutes) electrical metering data sent by a smart meter. Although such frequent metering data may be required by a utility or electrical energy distribution network for operational reasons, this data may not necessarily need to be attributable to a specific smart meter or consumer. It does, however, need to be securely attributable to a specific location (e.g. a group of houses or apartments) within the electricity distribution network. The method described in this paper provides a 3rd party escrow mechanism for authenticated anonymous meter readings which are difficult to associate with a particular smart meter or customer. This method does not preclude the provision of attributable metering data that is required for other purposes such as billing, account management or marketing research purposes.

Closed-form expressions for interconnection delay, coupling, and crosstalk in VLSIs
T. Sakurai
1993· IEEE Transactions on Electron Devices601doi:10.1109/16.249433

A closed-form formula for a waveform of the RC interconnection line with practical boundary conditions is derived. Expressions are also derived for the voltage slope and transition time of the RC interconnection and for coupling capacitance and crosstalk voltage height, which can be used in VLSI designs. Using the expressions, the optimum linewidth that minimizes RC delay and the trend of RC delay in the scaled-down VLSIs are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Bit Cost Scalable Technology with Punch and Plug Process for Ultra High Density Flash Memory
Hidetake Tanaka, M. Kido, K. Yahashi, M. Oomura +4 more
2007584doi:10.1109/vlsit.2007.4339708

We propose Bit-Cost Scalable (BiCS) technology which realizes a multi-stacked memory array with a few constant critical lithography steps regardless of number of stacked layer to keep a continuous reduction of bit cost. In this technology, whole stack of electrode plate is punched through and plugged by another electrode material. SONOS type flash technology is successfully applied to achieve BiCS flash memory. Its cell array concept, fabrication process and characteristics of key features are presented.

Effect of Ti substitution on the thermoelectric properties of (Zr,Hf)NiSn half-Heusler compounds
Shinya Sakurada, N. Shutoh
2005· Applied Physics Letters577doi:10.1063/1.1868063

The effect of Ti substitution on the thermoelectric properties of (Zr,Hf)NiSn half-Heusler compounds was studied. It was found that the substitution of Ti for (Zr,Hf) reduced the thermal conductivity significantly to a low value of 3.0W∕mK at room temperature. In addition, a remarkable enhancement of the Seebeck coefficient due to Ti substitution was observed. Furthermore, doping of the Sn sites in (Ti,Zr,Hf)NiSn with Sb led to a reduction in the electrical resistivity and to a corresponding enhancement of the power factor. In Sb-doped (Ti,Zr,Hf)NiSn compounds, the dimensionless figure of merit, ZT, increased with the increase in temperature and reached a high maximum value of 1.5 at 700K.