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ABSTRACT: We have proposed the new micro column electron beam microscope fabricated with multi-gated field emitter array based on the first result that a crossover successfully observed with quintuple-gated FEA. In order to realize the fine focused electron beam less than several ten nm in diameter, the initial emission angle after emitting from tip surface has to be controlled narrowly. In this report, it was described that we have introduced a suppressor gate which was located below tip and fabricated double-gated field emitter array with extractor. It was demonstrated that the suppressor gate had an emission angle narrowed successfully.
Vacuum Nanoelectronics Conference (IVNC), 2010 23rd International; 08/2010
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ABSTRACT: This paper proposes an improved lattice-reduction aided (LRA) MMSE detection based on the Gram-Schmidt (GS) procedure. The proposed detection reduces the column vectors of the MIMO channel matrix using the LLL algorithm and the GS procedure to create mutually purely orthogonal column vectors of the reduced channel matrix. Then the decision boundary becomes the same as that for the ML detection. Compared to the conventional LRA MMSE detector, the proposed detector achieves much closer BER performances to those for the ML detector in both the 4 Ã 4 MIMO and the 8 Ã 8 MIMO systems.
Global Telecommunications Conference, 2009. GLOBECOM 2009. IEEE; 01/2010
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ABSTRACT: In this paper, we propose a new approach to the locomotion control of the trident snake robot, focusing on its ¿double-linked¿ case where the robot is composed of a triangular body and three branches of double-linked snakelike legs. Originally, this robot was proposed by the authors as a novel example of nonholonomic mobile robot. This robot is quite interesting from a theoretical point of view; the well-known LARC (Lie Algebra Rank Condition) for its nonlinear controllability has a unique structure that it contains two `generator' vector-fields and higher order Lie brackets, which makes its control problem extremely challenging. In this paper, for this difficult control problem, we first propose a design algorithm which partially achieves the desired locomotion. Then we discover that the resulting motion may or may not be a stable limit cycle, depending on the eigenvalues of the corresponding discrete-time dynamics on its Poincare¿ map. Finally, we propose a full controller design by combining the stable limit cycles. The validity of the proposed idea is examined by numerical simulations.
Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International Conference on; 11/2009
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ABSTRACT: Japan has been changing to an aging society with fewer children, and this trend is expected to escalate in the future. Considering the impact to Japanese society, medical and welfare support should be improved. However, current care support is quite poor. Especially, smaller nursing facilities are in severe condition due to lack of sufficient help. In order to alleviate burden on nursing care, some works have done, but they assumed to use the care support system in larger nursing facilities or hospitals, and is oriented to provide sophisticated multiple functions. In this paper, we focus on supporting home nursing care case. We propose a simple vital information management system using domain name system, DNS. Adapting DNS scheme in the system enables to use various information equipments, including secondhand portable game machine, as a handheld terminal for register the patient's information. We show the details of encoding and embedding the vital information and interaction behavior between client and server. At the same time we introduce the DNSWrapper software which we newly developed. DNSWrapper can extracts and decodes the information from queried hostname, and plays a important role in our system. Finally we show the implementation and its estimation.
Networking, Sensing and Control, 2009. ICNSC '09. International Conference on; 04/2009
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ABSTRACT: This paper proposes an improved lattice-reduction aided (LRA) MMSE detection with successive interference cancellation (SIC) using both the forward and the backward (F&B) reduction LLL algorithms. We also apply a simple list detection to the F&B-LRA MMSE with SIC. The proposed detector provides good BER performance relatively close to that with the ML detection for both QPSK and 16QAM in the 8times8 MIMO system.
Advanced Technologies for Communications, 2008. ATC 2008. International Conference on; 11/2008
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ABSTRACT: This paper proposes a combined forward and backward lattice-reduction aided detection scheme to improve estimation of transmitted signals in lattice-reduction aided (LRA) MMSE MIMO systems. The cross-correlation between the forward and the backward reduced channel matrices is also analyzed to make sure that the proposed detector achieves more reliable estimates. The proposed detector achieves much better BER performance than the conventional LRA detector in the 4 x 4 and the 8 x 8 MIMO systems. It is also shown that the achieved BER curve moves closer to the curve of the ML detector than that of the conventional LRA MMSE detector.
Advanced Technologies for Communications, 2008. ATC 2008. International Conference on; 11/2008
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ABSTRACT: This paper proposes a novel lattice-reduction aided (LRA) detection in MIMO systems by improving the LRA-MMSE detection. The proposed detection scheme makes five transform matrices by iteratively reducing the columns of the channel matrix. Using the five transform matrices, five estimates of the transmitted signal are created, among which the most reliable estimate is chosen. The transmit signal energy is saved about 7dB at BER=10<sup>-5</sup>, and the BER slope became much steeper, which is almost the same as that with the ML detection in the 8times8 MIMO system.
Advanced Technologies for Communications, 2008. ATC 2008. International Conference on; 11/2008
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ABSTRACT: In helicopter satellite communications, the periodic blockage of the received signal and the carrier frequency fluctuation are the most important problems. In this paper, we propose a novel pre-detection time diversity combining scheme with accurate automatic frequency controller (AFC) for helicopter satellite communications. In the proposed scheme, a novel AFC tracks and removes the carrier frequency fluctuation due to Doppler shift exactly, and the in-phase combining of the time diversity signal is performed before the coherent detection. Results of computer simulation show that the proposed scheme improves the BER performance of the previous post-detection combining scheme.
Advanced Technologies for Communications, 2008. ATC 2008. International Conference on; 11/2008
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ABSTRACT: This paper proposes a combined forward and backward lattice reduction scheme to improve estimation of transmitted signals in lattice-reduction aided (LRA) MMSE MIMO systems. The cross-correlation between the forward and the backward transform matrices is also analyzed to make sure that the proposed detector achieves more reliable estimates. The proposed detector achieves better BER performance than the conventional LRA detector. The achieved BER curve is improved by 3.5 dB at BER=10<sup>-5</sup> over the curve of the conventional LRA MMSE detector in the 8times8 MIMO.
Vehicular Technology Conference, 2008. VTC 2008-Fall. IEEE 68th; 10/2008
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ABSTRACT: Lattice reduction aided (LRA) detection with the LLL algorithm has been investigated to achieve the MIMO channel capacity with low computational complexity. This paper proposes an improved LRA-MMSE detection using the forward and the backward reduction LLL algorithms for the 8times8 MIMO to obtain more reliable estimates of the transmitted signals. The proposed method achieved much better BERs than the conventional LRA detection. The transmit signal energy could be saved about 3.5 dB at BER=10<sup>-5</sup>, and the BER slope became much steeper, which is almost the same as that with the maximum likelihood detection.
Personal, Indoor and Mobile Radio Communications, 2008. PIMRC 2008. IEEE 19th International Symposium on; 10/2008
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ABSTRACT: Recently, lattice reduction aided (ERA) detectors have been introduced into Vertical Bell-Labs Layered Space-Time (V-BEAST) systems to obtain nearly optimal bit error rate (BER) performance for only small additional complexity. In this paper, the layer error characteristics of LRA-V-BLAST detectors are analyzed and compared with those of conventional V-BLAST ones. Two important conclusions are drawn for the LRA-V-BLAST detectors. First, the variation of their mean square error (MSE) within each detection iteration is not as large as in conventional V-BLAST detectors. Second, thanks to lattice reduction there exists an inherent sub-optimal detection order from the last to the first layer. These conclusions allow LRA-V-BLAST detectors to avoid optimal ordering to further reduce the complexity. LRA-V-BLAST detectors without optimal ordering are shown to obtain almost the same BER performance of LRA-V-BLAST detector with optimal ordering
Personal, Indoor and Mobile Radio Communications, 2006 IEEE 17th International Symposium on; 10/2006
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ABSTRACT: In this paper, we propose two minimum mean square error (MMSE)-based multiuser detectors, called the combined MMSE and maximum likelihood (MMSE-ML) multiuser detector and the combined MMSE and successive interference cancellation (MMSE-SIC) multiuser detector, for an uplink space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) system. Both detectors provide significantly improved bit error rate (BER) over the conventional MMSE multiuser detector while requiring the same complexity order. Moreover, the combined MMSE-ML detector exhibits better BER than the combined MMSE-SIC, particularly, in a system with a small number of users
Personal, Indoor and Mobile Radio Communications, 2005. PIMRC 2005. IEEE 16th International Symposium on; 10/2005
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ABSTRACT: A seventy-two year-old man, who complained of severe back pain, was referred to our hospital. Digital subtraction angiogram (DSA) delineated an extracardiac unruptured aneurysm of the right coronary sinus of Valsalva and acute type B aortic dissection. Patch plasty of the right coronary sinus with reimplantation of the right coronary artery using a Dacron graft was performed. Postoperative DSA confirmed successful reconstruction of the aortic root and the patent right coronary artery.
The Journal of cardiovascular surgery 11/2001; 42(5):625-7. · 1.56 Impact Factor
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ABSTRACT: Retrograde perfusion is gaining acceptance as a means of cerebral protection, but it remains unclear how long the brain is protected and whether it is effective in patients with preoperative cerebrovascular disease.
From January 1989 to August 1999, 205 patients--118 male and 87 female patients who ranged 12 to 86 years old, mean: 65.5 years old--underwent surgery at our hospital for aortic arch aneurysm using cerebral protection. We focused on mortality, stroke incidence and perioperative risk factor between 2 groups--selective cerebral and retrograde cerebral perfusion--also studying patients with preoperative cerebrovascular disease that influenced postoperative stroke.
The hospital mortality was 11.7% (selective cerebral perfusion group: 12%, retrograde group: 10.9%). Stroke occurred in 11 patients (5.3%), 4.7% in the selective cerebral perfusion group and 7.3% in the retrograde group. Preoperative cerebrovascular disease does not appear to be a risk factor for postoperative brain damage in aortic arch surgery. Regarding total replacement of the aortic arch, the incidence of postoperative brain damage in the retrograde group with preoperative cerebrovascular disease was higher than that in another group (p = 0.072). Cardiopulmonary bypass time and selective cerebral perfusion time in the patients with postoperative stroke were significantly longer than that in non-stroke group.
Preoperative cerebrovascular disease did not appear to be a risk factor in postoperative neurological deficit in the selective cerebral perfusion group. Prolonged selective cerebral perfusion time and cardiopulmonary bypass time may, however, lead to brain edema and cause neurological deficit.
The Japanese Journal of Thoracic and Cardiovascular Surgery 01/2001; 48(12):782-8.
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ABSTRACT: A 25-year-old woman with Marfan syndrome in the 37th week of pregnancy was referred for acute chest pain and dyspnea. An emergency Cesarean section was performed because of fetal distress. Intraoperative echocardiography at the end of the Cesarean section showed dilatation of the aortic root and dissection of the ascending aorta. The patient underwent replacement of the aortic root and the ascending aorta on the following day because of uterine bleeding. The postoperative course was uneventful for the mother and her baby.
Japanese Circulation Journal 10/2000; 64(9):729-30.
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A. Yamazaki, T. Fujino,
K. Inoue,
I. Hayashi,
H. Noda,
N. Watanabe,
F. Morishita,
J. Ootani,
M. Kobayashi,
K. Dosaka,
Y. Morooka,
H. Shimano,
S. Soeda,
A. Hachisuka,
Y. Okumura,
K. Arimoto,
S. Wake,
H. Ozaki
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ABSTRACT: Advanced 3D graphics (3DG) technology will be used in console game
machines, and it is desired to develop a rendering controller chip which
can handle real time 3D animation with true colors. Embedded DRAM
(eDRAM) technology attracts attention of the 3DG systems, because only
eDRAM can satisfy the required data rate. Four or more pipelines, 200
MHz pipeline operating frequency, and 64 b per pixel are required. With
this configuration, the required data rate is 39.4 GB/s, assuming the
total penalty of 35% for page miss and video refresh. Furthermore, a 120
Mb frame buffer is required for a 1280×1024-pixels screen. This
0.18 μm 32 Mb eDRAM macro satisfies these requirements
Solid-State Circuits Conference, 2000. Digest of Technical Papers. ISSCC. 2000 IEEE International; 02/2000
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ABSTRACT: For the future large scale application of superconducting (SC) RF
cavities like TESLA, one has to fabricate the cavities cheaply to
achieve high gradients and high Q values (E<sub>acc</sub>>25 MV/m,
Q>1×10<sup>10</sup>). The amount of niobium material has to be
decreased and the complex welding structure should be eliminated to
reduce the fabrication cost. Here, the authors propose to fabricate
seamless clad cavities of niobium and copper material and report the
results of a feasibility study
IEEE Transactions on Appiled Superconductivity 07/1999; · 1.04 Impact Factor
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ABSTRACT: A 16-year-old man was found to have an enlarged cardiac silhouette. Primary chylopericardium was diagnosed when pericardiocentesis yielded the characteristic milky-white fluid. The thoracic duct was easily identified by giving milk and butter and an injection of ethylene blue immediately before the operation. Intraoperative thoracic ductography showed no abnormal findings. Mass ligation of the thoracic duct above the diaphragm and partial pericardiectomy were successfully performed through a right thoracotomy approach. In addition, many of the lymphatics were ligated above the diaphragm. The right thoracotomy approach was a useful method for resection and ligation of the thoracic duct just above the diaphragm. Follow-up showed no accumulation of pericardial fluid or pleural effusion.
Japanese Circulation Journal 02/1999; 63(1):59-60.
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ABSTRACT: <Case 1> A 48-year old woman underwent surgery for an aortic arch aneurysm with stenosis or dilatation of three arch vessels caused by aortitis syndrome. Total arch replacement and reconstruction of three arch vessels were performed with hypothermic selective cerebral perfusion (SCP). To avoid atheroembolism and malperfusion to the brain, the rt. common carotid artery was perfused via the rt. subclavian artery through the dacron vascular graft and the lt. subclavian artery was cannulated and perfused distally to stenosis. <Cases 2> A 65-year-old man who had an atherosclerotic aortic arch aneurysm with severe stenosis of the brachiocephalic artery underwent operation. In the operation, extracorporeal circulation was instituted with the arterial return through the lt. subclavian artery. Same as case 1, total arch replacement and reconstruction of three arch vessels were performed under hypthermic SCP. In this case, the left common carotid artery was transected and cannulated directly into the vessel, instead of cannulation through the aortic lumen because of atheromatous plaques in the orifice of the left common carotid artery. The patients recovered uneventfully and doing well now.
Kyobu geka. The Japanese journal of thoracic surgery 12/1998; 51(13):1074-9.
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The Japanese Journal of Thoracic and Cardiovascular Surgery 05/1998; 46 Suppl:112-5.
