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[show abstract]
[hide abstract]
ABSTRACT: To grasp conditions of patients and implantable artificial hearts, it is important to measure the pump flow rate continuously and noninvasively. In this study, a miniaturized mass-flow meter for discharged patients with an implantable axial flow blood pump was developed. The mass-flow meter makes use of centrifugal force generated by mass-flow rate around the curved cannula. Based on the computational fluid dynamics (CFD) analysis, the prototype miniaturized mass-flow meter was developed. Two strain gauges were adopted as the sensor elements. The first strain gauge, attached to the straight area, measured static pressure. The second strain gauge, attached to the curved area, measured static pressure and the centrifugal force. By subtracting the output of the first strain gauge from the output of the second strain gauge, the mass-flow rate was determined. In the evaluation tests using the mock-up circulation loop, the mass-flow meter was compared to a commercial flow meter. As a result, measurement error was less than 1.0 L/min, and time delay was less than 0.2 s. We confirmed that the miniaturized mass-flow meter could accurately measure the mass-flow rate continuously and noninvasively.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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[show abstract]
[hide abstract]
ABSTRACT: The amount of accessible information in the Internet increases every day and it becomes greatly difficult to deal with such a huge source of information. Consequently, Recommender Systems (RS) which are considered as powerful tools for Information Retrieval (IR), can access these available information efficiently. Unfortunately, the recommendations accuracy is seriously affected by the problems of data sparsity and scalability. Additionally, the time of recommendations is very essential in the Recommender Systems. Therefore, we propose a proficient dimensionality reduction-based Collaborative Filtering (CF) Recommender System. In this technique, the Singular Value Decomposition-free (SVD-free) Latent Semantic Indexing (LSI) is utilized to obtain a reduced data representation solving the sparsity and scalability limitations. Also, the SVD-free extremely reduce the time and memory usage required for dimensionality reduction employing the partial symmetric Eigenproblem. Moreover, to estimate the optimal number of reduced dimensions which greatly influences the system accuracy, the Particle Swarm Optimization (PSO) algorithm is utilized to automatically obtain it. As a result, the proposed technique enormously increases the recommendations prediction quality and speed. In additions, it decreases the memory requirements. To show the efficiency of the proposed technique, we employed it to the MovieLens dataset and the results was very promising.
Natural Language Processing and Knowledge Engineering, 2009. NLP-KE 2009. International Conference on; 10/2009
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[show abstract]
[hide abstract]
ABSTRACT: This paper proposes a fast fault recovery method for the wide area Ethernet. To achieve fast recovery, a pre-established forwarding table is introduced. The pre-established table is looked up when a fault occurs, and frames are forwarded without frame loss. Ethernet lacks of fault recovery features required in Wide Area Network (WAN) since it is originated as Local Area Network (LAN) technology. Protection or restoration is a typical method for fault recovery, but a lot of frame losses are inevitable. Our proposal can decrease frame losses since frames are forwarded without waiting for path switching to be completed to use the pre-preparation table. In addition, the proposed method can be operated with the legacy forwarding method seamlessly. The simulation results show that frame loss decreases to 40% or less with our proposed method.
Communications, 2009. ICC '09. IEEE International Conference on; 07/2009
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[show abstract]
[hide abstract]
ABSTRACT: In this study, we propose that optimization of the input pulse results in a high-speed response and rebound suppression for solenoids. This input is given by two impulse voltage responses. The first impulse response rapidly drives the solenoid plunger, and the second suppresses the rebound that occurs upon reaching the reference position. In the past, these pulse timings have been determined by trial and error. In the present study, the solenoid model was built, and optimal timing of the input pulses was derived by giving an evaluation function considering both the plungerpsilas rebound and the arrival time.
Advanced Computer Control, 2009. ICACC '09. International Conference on; 02/2009
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M. Ito,
K. Nitta,
K. Ohno,
M. Saigusa, M. Nishida,
S. Yoshioka,
T. Irita,
T. Koike,
T. Kamei,
T. Komuro,
T. Hattori,
Y. Arai,
Y. Kodama
[show abstract]
[hide abstract]
ABSTRACT: Supporting both WCDMA with HSDPA and GSM/GPRS/EDGE, the 9.3 times 9.3 mm<sup>2</sup> SoC fabricated in triple-Vth 65 nm CMOS, has three CPU cores and 20 separate power domains. Unused power domains can be powered down to reduce the leakage power. Partial clock activation scheme especially focused on music playback scene dynamically stops a PLL and clock trees when not necessary and reduces power consumption from 33.6 mW to 19.6 mW. IP-MMU translates virtual address to physical address for 18 hardware-IPs and virtual address space can be allocated when necessary and can be freed after its operation, reducing external memory by 43 MB. Video performance of D1 (720 times 520) size with 30 frames per second for MPEG/AVC decoding and encoding can be achieved under mixed virtual and physical address usage.
IEEE Journal of Solid-State Circuits 02/2009; · 3.23 Impact Factor
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[hide abstract]
ABSTRACT: In sign language, hand positions and movements represent meaning of words. Hence, we have been developing sign language recognition methods using both of hand positions and movements. However, in the previous studies, each feature has same weight to calculate the probability for the recognition. In this study, we propose a sign language recognition method by using a multi-stream HMM technique to show the importance of position and movement information for the sign language recognition. We conducted recognition experiments using 21,960 sign language word data. As a result, 75. 6% recognition accuracy was obtained with the appropriate weight (position:movement=0. 2:0. 8), while 70. 6% was obtained with the same weight. From the result, we can conclude that the hand movement is more important for the sign language recognition than the hand position. In addition, we conducted experiments to discuss the optimal number of the states and mixtures and the best accuracy was obtained by the 15 states and two mixtures for each word HMM.
Universal Communication, 2008. ISUC '08. Second International Symposium on; 01/2009
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[show abstract]
[hide abstract]
ABSTRACT: In text-independent (TI) speaker identification, the variation of phonetic information strongly affects the performance of speaker identification. If this phonetic information in his/her speech data can be suppressed, a robust TI speaker identification system will be realized by using speech features having less phonetic information. In this paper, we propose a TI speaker identification method that suppresses the phonetic information by a subspace method, under the assumption that a subspace with large variance in the speech feature space is a ldquophoneme-dependent subspacerdquo and a complementary subspace of it is a ldquophoneme-independent subspacerdquo. Principal Component Analysis (PCA) is utilized to construct these subspaces. We carried out GMM-based speaker identification experiments using both a new feature vector of the proposed method and the conventional MFCC. As a result, the proposed method reduced the identification error rate by 21% compared with the conventional MFCC.
Communication Technology, 2008. ICCT 2008. 11th IEEE International Conference on; 12/2008
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[show abstract]
[hide abstract]
ABSTRACT: Multi-domain GMPLS layer-2 switch capable network with VLAN tag swapping is demonstrated. In this demonstration, we verify three features, establishing path with designating VLAN ID, swapping VLAN ID on software switch, and management of VLAN IDs per domain.
Optical Internet, 2008. COIN 2008. 7th International Conference on; 11/2008
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[show abstract]
[hide abstract]
ABSTRACT: This paper proposes an adaptive resource reservation protocol for high-speed resource information advertisement. The adaptive resource reservation protocol (ARRP) is a protocol that adaptively decides whether to uses a 1-way reservation scheme or 2-way reservation scheme on the basis of resource information in the route calculation. Examples of the resource information are unreserved bandwidth and unreserved wavelength. The 1-way reservation is used when all links along the calculated route has enough resources. Otherwise, the 2-way reservation is used. GMPLS (Generalized Multi-Protocol Label Switching) network, the source router decides a label switched path (LSP) route using collected resource information from the network. The resource information is advertised by an OSPF- TE (Open Shortest Path First-Traffic Engineering) protocol. If the unreserved resource information of calculated LSP route is too old and inconsistent with the current information, the resources on the LSP route cannot be reserved and thus data loss will be occurred. In order to support real-time unreserved information update, quite a lot of update packet transmissions are needed. It causes increasing of the processing load of all routers. Therefore OSPF-TE cannot advertise real-time unreserved resource information. In the proposed method, when a LSP route is established or released by ARRP, only one packet informs update information of each links along LSP route to all edge routers. The proposed method can support more frequent updates by decreasing the amount of the update packets and can advertise the real-time resource information. By use of the real-time resource information, the proposed method certainly guarantees the reservation of resources on LSP route in spite of the 1-way reservation. By the computation simulation, it is indicated that the number of the control packets in proposed method is one digit less than that in the conventional OSPF-TE. Compared to the OSPF-TE, the proposed me-
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thod keeps low blocking probability even when traffic occurs more frequently. Thus, it is shown that the proposed method effectively use network resources.
Communications, 2008. APCC 2008. 14th Asia-Pacific Conference on; 11/2008
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[show abstract]
[hide abstract]
ABSTRACT: This paper proposes a generation method of a subjectspecific emotional feature space using the Self-Organizing Map and the Counter Propagation Network. The feature space expresses the correspondence relationship between the change of facial expression pattern and the strength of emotion on the two-dimensional space centering on ldquopleasantnessrdquo and ldquoarousalrdquo. Experimental results suggested that our method was useful to estimate strength and mixture level of six basic emotions.
Automatic Face & Gesture Recognition, 2008. FG '08. 8th IEEE International Conference on; 10/2008
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[show abstract]
[hide abstract]
ABSTRACT: We have developed a centrifugal blood pump with hydrodynamic bearings and semi-open impeller, and evaluated the levitation performance test and the hemolysis test. This pump is operated without any complicated control circuit and displacement-sensing module. The casing diameter is 74 mm and the height is 38 mm including flanges for volts. The weight is 251 g and the volume is 159 cm<sup>3</sup>. By changing the stator relative position against the rotor, the levitation characteristics of the impeller can be adjusted. The diameter of impeller is 36 mm and the height is 25 mm. The impeller is levitated by the thrust bearing of spiral groove type and a radial bearing of herringbone type. The pump performance was evaluated through the levitation performance test and the hemolysis test. As a result, the normalized index of hemolysis (NIH) was reduced from 0.72 g/100 L to 0.024 g/100 L corresponding to the changes of the groove direction of the hydrodynamic bearing and the expansion of the bearing gap. During these studies, we confirmed that the hemolytic property was improved by balancing the fluid dynamic force and the magnetic force.
Engineering in Medicine and Biology Society, 2007. EMBS 2007. 29th Annual International Conference of the IEEE; 09/2007
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[show abstract]
[hide abstract]
ABSTRACT: This paper presents a GxL device that exhibits an extremely high contrast ratio. We achieved a very high device contrast ratio of 34700 by optimizing the design of the posts that support the ribbons and flattening the sacrificial layer. By miniaturizing the chip and improving the packaging, we were able to shrink the GxL module by 75%. Dramatic image quality improvement of the GxL projector system was confirmed. No degradation of the GxL device was observed after a temperature cycling test.
Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International; 07/2007
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[show abstract]
[hide abstract]
ABSTRACT: Finger braille is one of the communication methods for the deaf blind. The interpreter types braille codes on the fingers of deaf blind. Finger braille seems to be the most suitable medium for real-time communication by its speed and accuracy of transmitting characters. We hypothesize that the prosody information exists in the time structure and strength of finger braille typing. Prosody is the paralinguistic information that has functions to transmit the sentence structure, prominence, emotions and other form of information in real time communication. In this study, we measured the surface electromyography (sEMG) of finger movement to analyze the typing strength of finger braille. We found that the typing strength increases at the beginning of a phrase and a prominent phrase. The result shows the possibility that the prosody in the typing strength of finger braille can be applied to create an interpreter system for the deafblind
Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE; 10/2006
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[show abstract]
[hide abstract]
ABSTRACT: This paper presents a study on the development and control of a micro biped walking robot using shape memory alloys (SMAs). We propose a flexible flat plate (FFP) consisting of a polyethylene plate and SMAs. Based on a detailed investigation of the properties of the SMA-based FFP structure, we develop a lightweight micro walking robot incorporating multiple SMA-based FFPs. The walking robot has four degrees of freedom and is controlled by switching the ON-OFF current signals to the SMA-based FFPs. The switching timing, central to the control strategy to achieve walking behavior, is determined through experiments. The micro robot realizes biped walking by transferring the elastic potential energy (generated by deflections of the SMA-based FFPs) to kinematic energy. The resulting micro biped walking robot weighs a mere 2.8 g (with a height of 70 mm). Our experimental results demonstrate the viability and utility of the micro walking robot with the proposed SMA-based FFPs and the control strategy to achieve walking behavior
Robotics and Automation, 2006. ICRA 2006. Proceedings 2006 IEEE International Conference on; 06/2006
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[show abstract]
[hide abstract]
ABSTRACT: The performance of grating light valve (GLV™) chips can be increased by optimizing their ribbon structures [ 1]. A GLV is a one-dimensional light modulator using diffraction that can be applied to a high definition display by scanning the second dimension. We applied blazed GLV, which diffracts in only one direction [ 2], and achieved a jump in contrast from 3000:1 to 10000:1. Moreover, we achieved a 55 to 70% improvement in optical efficiency due to nanometer-order control of blazed GLV ribbon. These technologies were applied to the 2005-inch theater system “ GxL™ Laser Dream Theater” [ 3, 4].
Micro Electro Mechanical Systems, 2006. MEMS 2006 Istanbul. 19th IEEE International Conference on; 02/2006
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[show abstract]
[hide abstract]
ABSTRACT: There are many tasks to be performed by space robots. However a
single end-effector can not meet the individual task's requirements.
NASDA is to launch an experimental robot satellite named ETS-VII. The
satellite has a 6-DOF robot-arm to handle many experimental payloads.
Payloads vary in mass, shape and size. Interfaces between payloads and
the end-effector are standardized using grapple fixtures. Additional
tools with grapple fixtures are also developed to meet specific task
requirements. This paper shows current status of the space-robot's EVA
end-effector and development result of the ETS-VII's end-effector,
grapple fixtures and tools
Intelligent Robots and Systems '96, IROS 96, Proceedings of the 1996 IEEE/RSJ International Conference on; 12/1996
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[show abstract]
[hide abstract]
ABSTRACT: A scaled up model of a centrifugal blood pump was used to
visualize the flow through the vanes. By using a high speed video camera
it was possible to clarify the flow patterns. The study aimed to show
the absolute and relative flow patterns and also to compare blood pump
models with and without washout holes. It was found that washout holes
did not significantly change the flow patterns through the vanes. As
washout holes decrease the stagnating area in the shroud side and
decrease the fluid dynamic lifting force, their use is suggested in
future blood pumps
Engineering in Medicine and Biology Society, 1996. Bridging Disciplines for Biomedicine. Proceedings of the 18th Annual International Conference of the IEEE; 12/1996
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[show abstract]
[hide abstract]
ABSTRACT: Hydrogen-free carbon film deposition is studied through molecular dynamics (MD) simulation. MD simulation is performed for low-energy carbon particle impacts on carbon surfaces at room temperature. Deposition energy is considered up to E = 100 eV per carbon atom. Deposited surface is set into amorphous, and (1 1 1) surface of diamond crystal is considered in order to compare. For (1 1 1) surface, we found three characteristic regions. The deposition frequently results in the shallow trapping in E ⩽ 20 eV. In E ⩾ 30 eV, the deep trapping occurs about normal incidence, and the reflection appears about grazing incidence. For the amorphous surface, however, the reflection and the deep trapping are suppressed.
Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 269(14):1752-1754. · 1.21 Impact Factor
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JC Sandoval,
Y Nakagawa-Toyama,
D Masuda,
Y Tochino,
H Nakaoka,
R Kawase,
M Yuasa-Kawase,
K Nakatani,
M Inagaki,
K Tsubakio-Yamamoto,
T Ohama,
A Matsuyama, M Nishida,
M Ishigami,
I Komuro,
S Yamashita
[show abstract]
[hide abstract]
ABSTRACT: AIM: Postprandial hypertriglyceridemia (PHTG) has been shown repeatedly to be associated with metabolic syndrome and atherosclerotic cardiovascular diseases. We have recently reported that ezetimibe inhibits PHTG in patients with type IIb hyperlipidemia. Ezetimibe was also reported to atten-uate PHTG in combination with low-dose statins in patients with obesity or metabolic syndrome. We reported CD36-deficient (CD36KO) mice as a new model for PHTG, in which the synthesis of chylomicron (CM) in the small intestines is enhanced. In the current study, we investigated the effect of ezetimibe on PHTG in this mouse model of metabolic syndrome.
Journal of atherosclerosis and thrombosis. 17(9):914-24.
