-
[show abstract]
[hide abstract]
ABSTRACT: ICT and MEMS technology are becoming pervasive. Therefore, wearable sensors are receiving a lot of attention. This raises the feasibility of various sensor-based services. This paper introduces a gait authentication method based on wearable sensors. We capture gait data from a wearable sensor and analyze personal gait characteristics on the basis of the data obtained. We propose and evaluate an authentication algorithm. Results confirm that when the threshold value was 18.4, EER was 23.1%.
Defense Science Research Conference and Expo (DSR), 2011; 09/2011
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a novel motor design concept that utilizes amorphous cut cores in the stator and ferrite magnets in the rotor to obtain a high-efficiency motor. This motor employs a six-pole nine-slot axial gap construction and aims to provide 90% efficiency with decreased size and low cogging torque for fan motor applications. Amorphous cut cores are applied to the stator to decrease iron loss and save motor space. Skewed magnets are employed to decrease cogging torque. Three-dimensional finite element analysis was used to analyze motor performance. In order to verify the accuracy of the design, a trial motor was constructed, and a large range of experiments was conducted to measure the motor characteristics. The results of the trial motor meet the design goals.
IEEE Transactions on Industry Applications 07/2011; · 1.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We study electrical properties of metal/Ge contacts with an atomically controlled interface, and compare them with those with a disordered one, where atomically controlled interfaces can be demonstrated by using Fe <sub>3</sub> Si / Ge (111) contacts. We find that the Schottky barrier height of Fe <sub>3</sub> Si /n -Ge (111) contacts is unexpectedly lower than those induced by the strong Fermi-level pinning at other metal /n -Ge contacts. For Fe <sub>3</sub> Si /p -Ge (111) contacts, we identify clear rectifying behavior in I-V characteristics at low temperatures, which is also different from I-V features due to the strong Fermi-level pinning at other metal /p -Ge contacts. These results indicate that there is an extrinsic contribution such as dangling bonds to the Fermi-level pinning effect at the directly connected metal/Ge contacts.
Applied Physics Letters 05/2010; · 3.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An axial-gap permanent-magnet motor that utilized tape wound amorphous cores was designed, manufactured and tested. The motor employs two 8-pole rotors and one 12-slot amorphous cores stator. In order to reduce iron loss, the magnetic and iron loss properties of ring-shaped amorphous cores with different lamination direction are investigated determine a suitable core structure for motor application. Tape wound core was chosen because of its simple manufacture process. In the motor design, lamination direction of AMM core was designed perpendicular to field produced by rotors to decrease eddy current loss. Three-dimensional finite element analysis (3D FEA) was used to model and analyze the motor performance. No-load tests and load tests of the trial motor were conducted to demonstrate the feasibility of the motor design and verify the 3-D FEA calculation. This paper presents the details of amorphous cores' properties, motor design and test results.
IEEE Transactions on Magnetics 03/2010; · 1.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Societies are aging around the world. Elderly people are falling more often leading to serious injury and even death. Therefore,
it is important to detect falls immediately even in private houses. Detecting falls by sensors worn by the aged is a powerful
approach that is being actively researched because the sensors are cheap and light, and can provide real time response. This
research proposes and experimentally evaluates a template method that can process the data output by a 3-axis acceleration
sensor to detect falls reliably.
KeywordsAcceleration sensor–Fall detection–Aging society–Template method
12/2009: pages 1335-1338;
-
[show abstract]
[hide abstract]
ABSTRACT: A new identification technique for hole-assisted optical fibre cord is proposed, which is realised by launching visible light into the fibre core and observing the leaked light from a bent fibre, without affecting communication.
Electronics Letters 12/2009; · 0.96 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a noble motor design concept that utilizes amorphous cut cores in the stator to obtain a high efficiency motor. This motor employs 6-pole, 9-slot axial gap construction and aims to provide high efficiency with small size and low cogging torque for fan motor applications. Amorphous cut cores are applied to the stator to decrease iron loss and save motor space. The magnets with distinct shapes are employed to decrease cogging torque. 3D finite element analysis was used to model and analyze motor performance. In order to verify the design concept, a trial motor was constructed and a large range experiments were conducted to measure motor characteristics.
Electrical Machines and Systems, 2009. ICEMS 2009. International Conference on; 12/2009
-
[show abstract]
[hide abstract]
ABSTRACT: This paper proposes a method of characteristics calculation for permanent magnet synchronous machines (PMSMs) using static finite element analysis (FEA) and steady-state dq-axis equations. The method calculates characteristics such as torque, voltage, current, inductances, etc. under any balanced steady-state load conditions. Various types of input condition can be selected to identify the load condition. For example, the characteristics are calculated at the load condition that has the smallest current amplitude and the inputted torque and frequency. The computing time of the method is small because the FEA is static. The calculated results of a 750-watt PMSM under minimum-current control and field-weakening control have agreed well with the measurements. The method is useful in PMSM development and design.
Electrical Machines, 2008. ICEM 2008. 18th International Conference on; 10/2008
-
Review of Scientific Instruments 03/2008; · 1.37 Impact Factor
-
T. Sanuki,
T. Iwamoto,
K. Ota,
T. Komoda,
H. Yamazaki,
A. Eiho,
K. Miyagi,
K. Nakayama,
O. Fuji,
M. Togo, [......],
M. Ikeda,
M. Saito,
H. Naruse, Y. Enomoto,
T. Kitano,
M. Iwai,
K. Imai,
N. Nagashima,
T. Kuwata,
F. Matsuoka
[show abstract]
[hide abstract]
ABSTRACT: This paper describes the fabrication and performance of CMOS transistors featuring flash lamp annealing (FLA) for 45 nm node. We show, for the first time, applying FLA prior to spike RTA as S/D annealing is effective to enhance the channel stress in PFET with epitaxially grown SiGe (eSiGe) S/D. In NFET, FLA recovers the damaged layer in S/D extension caused by implantation and suppresses the transient enhanced diffusion (TED). These improvements result in 11% and 8% higher saturation drive current, and IDSAT=750muA/mum and 1160muA/mum for IOFF=100 nAmum at Vdd=lV in PFET and NFET, respectively. We also report the pattern density dependence of performance gain from FLA technique.
Electron Devices Meeting, 2007. IEDM 2007. IEEE International; 01/2008
-
A. Eiho,
T. Sanuki,
E. Morifuji,
T. Iwamoto,
G. Sudo,
K. Fukasaku,
K. Ota,
T. Sawada,
O. Fuji,
H. Nii, [......],
M. Ikeda,
M. Saito,
H. Naruse, Y. Enomoto,
Kitano,
S. Yamada,
K. Imai,
N. Nagashima,
T. Kuwata,
F. Matsuoka
[show abstract]
[hide abstract]
ABSTRACT: The effect of stress memorization technique (SMT) in performance and power reduction is maximized by choosing the appropriate stressor with large stress change by spike RTA. 30% mobility enhancement and 60% reduction of gate leakage have been achieved simultaneously. Stress distribution in channel region for SMT is confirmed to be uniform, hence layout dependency is minimized and performance is maximized in aggressively scaled CMOS with dense gate pitch rule (190 nm) in 45 nm technology node.
VLSI Technology, 2007 IEEE Symposium on; 07/2007
-
H. Nii,
T. Sanuki,
Y. Okayama,
K. Ota,
T. Iwamoto,
T. Fujimaki,
T. Kimura,
R. Watanabe,
T. Komoda,
A. Eiho, [......],
M. Iwai,
M. Saito,
M. Ikeda, Y. Enomoto,
H. Naruse,
K. Imai,
S. Yamada,
N. Nagashima,
T. Kuwata,
F. Matsuoka
[show abstract]
[hide abstract]
ABSTRACT: We present the state-of-the-art 45nm high performance bulk logic platform technology which utilizes, for the first time in the industry, ultra high NA (1.07) immersion lithography to realize highly down-scaled chip size. Fully renovated MOSFET integration scheme which features reversed extension and SD diffusion formation is established to meet Vt roll-off requirement with excellent transistor performance of Ion=1100muA/mum for nFET and Ion=700muA/mum for pFET at Ioff=100nA/mum. Also, we achieved excellent BEOL reliability and manufacturability by implementing hybrid dual-damascene (DD) structure with porous low-k film (keff=2.7)
Electron Devices Meeting, 2006. IEDM '06. International; 01/2007
-
[show abstract]
[hide abstract]
ABSTRACT: A key technology for realizing an effective k-value (keff) required for 45nm node is proposed. We studied the behavior of effective dielectric constant derived from capacitance of double-level copper interconnect wires with porous low-k material in detail. The porous low-k materials easily absorb moisture due to process damage and the dielectric constant drastically increases. We have confirmed that if moisture-controlled robust process integration is performed, a reasonably effective dielectric constant (2.8) is obtained corresponding to the ideal bulk k-value (2.4). However, when the sealing of passivation films is broken, the effective dielectric constant increases to the level derived from that of the damaged blanket film. In order to ensure a target capacitance of copper interconnect wire with porous low-k material, it is indispensable to perfectly seal a whole device area from moisture uptake
Interconnect Technology Conference, 2006 International; 07/2006
-
Y. Kagawa, Y. Enomoto,
T. Shimayama,
T. Kameshima,
M. Okamoto,
H. Kawshima,
A. Yamada,
T. Hasegawa,
K. Akiyama,
H. Masuda,
M. Miyajima,
H. Shibata,
S. Kadomura
[show abstract]
[hide abstract]
ABSTRACT: An integration method using effective porogen control to improve the reliability of 45-nm (hp65) Cu interconnects with ultra low-k (ULK) stacked $porous-polyarylene (PAr)/porous-SiOC (k = 2.3/2.3) - hybrid dual damascene (DD) structures. By optimizing an electron beam (EB) assisted thermal cure, the target amount of porogen left in via inter layer dielectric (ILD) to enhance the etching damage resistance of the film. Quantitative analyses of the porogen amount showed that the remaining porogen was eliminated using a second thermal cure after the DD patterning. We found that the remaining porogen keeps the backbone structure of via-ILD from being damaged by active radicals during trench etching
Interconnect Technology Conference, 2006 International; 07/2006
-
[show abstract]
[hide abstract]
ABSTRACT: A nationwide survey documented 117 cases of Creutzfeldt-Jakob disease (CJD) transmitted from cadaveric dura mater grafts in
Japan to September 2004. Of these, 110 patients were identified to have received the same type of lyophilized cadaveric dura
mater graft during the period between 1978 and 1991. Incubation period from grafting to onset of symptoms varied from 16 months
to 23 years, with most patients developing neurological symptoms after 2 to 15 years. We conducted q retrospective review
of the full medical records of 107 of dura-related CJD (dCJD) patients. Patients were divided into two groups by site of neurosurgical
or orthopedic procedure (supratentorial vs. infratentorial). Hemiparesis or hemianopsia developed as an initial manifestation
in 31.9% of 47 patients with supratentorial grafts but did not develop among any of the infratentorial group (p<0.0001). Conversely,
brainstem symptoms (nystagmus, diplopia, ipsilateral hearing loss, facial paresis or paresthesia) were noted in 25.0% of the
infratentorial group, but were not seen in the supratentorium group (p<0.0001).
06/2006: pages 31-40;
-
[show abstract]
[hide abstract]
ABSTRACT: The effects of Dy doping and sintering parameters on the properties of BaTiO3 ceramics were studied. The average grain size decreases with increasing Dy content and is controlled at ∼1.5 μ m by 0.8 at.% Dy. The Curie temperature change, associated with ≤1.2 at.% Dy, is <3°C. The dielectric constant is ∼2600 for specimens doped with 0.8 at.% Dy, calcined at 1200°C, and sintered at 1450°C. The dielectric constant variation with ambient temperature is much less than that of conventional BaTiO3 ceramics. Lattice constant c decreases with increasing Dy concentration whereas a increases slightly. The effects of grain size on dielectric constant, lattice parameters, and linear thermal expansion coefficient are more pronounced than the chemical effects of Dy doping in the ferroelectric state, whereas in the paraelectric state, these characteristics are almost independent of grain size as well as Dy concentration. The decrease in the frequency of occurrence of 90° twins with decreasing grain size implies that internal stress, which develops when BaTiO3 ceramics are cooled below Tc, strongly influences the effects of grain size.
Journal of the American Ceramic Society 06/2006; 60(3‐4):97 - 101. · 2.27 Impact Factor
-
T. Fujimaki,
K. Higashi,
N. Nakamura,
N. Matsunaga,
K. Yoshida,
N. Miyawaki,
M. Hatano,
M. Hasunuma,
J. Wada,
T. Nishioka,
K. Akiyama,
H. Kawashima, Y. Enomoto,
T. Hasegawa,
K. Honda,
M. Iwai,
S. Yamada,
F. Matsuoka
[show abstract]
[hide abstract]
ABSTRACT: Moisture induced via failure (MIVF) is studied for 45nm interconnect technology using porous low-k films. Test patterns are designed to examine the layout dependence of the MIVF. Some fundamental and important layout dependencies of the via resistance increase are investigated and considered for the first time. It has been found that the MIVF has not been suppressed, even though multiple vias structure is adopted. On the contrary, local wiring pattern density close to via and dummy wiring pattern area size strongly affect via resistance increase. A model with moisture ventilation can successfully explain those layout dependencies. It is confirmed that the MIVF is completely suppressed by the control of dummy pattern layout
Electron Devices Meeting, 2005. IEDM Technical Digest. IEEE International; 01/2006
-
[show abstract]
[hide abstract]
ABSTRACT: Cu interconnects reliability has been drastically improved by the introduction of Ag doped Cu (Cu-Ag) alloy seed. The usage of Cu-Ag remarkably suppressed stress induced voiding (SiV) in the lower wide metal which appeared by the additional anneal to prevent the degradation of the barrier metal. It has been explained by the Cu extrusion model where the void formation was caused by the poor adhesion between the upper barrier metal and the extruded lower metal under the via. The thermal stress hysteresis curve of Cu-Ag which shows the shift of the softening temperature to higher suggests more thermal resistance to Cu extrusion than pure Cu. Also no degradation of interconnects performance and the minimum increase of the resistance were verified. These indicate that Cu-Ag alloy is the most feasible candidate for the improvement of the reliability issues of Cu interconnects with porous low-k film for 45nm node and beyond.
Electron Devices Meeting, 2004. IEDM Technical Digest. IEEE International; 01/2005
-
[show abstract]
[hide abstract]
ABSTRACT: We have designed ring oscillators to test rapid single flux
quantum (RSFQ) circuits with passive transmission lines at high
frequencies. To reduce the width of the transmission line, design
methods for increasing the characteristic impedance of the transmission
line have been investigated and then we designed a 5-stage of Josephson
transmission line (JTL) receiver which can transform the impedance from
1 to 4 Ω by changing the critical current and the inductance. The
receiver, driver, and micro-strip line were inserted in a ring
oscillator. The ring oscillator fabricated with the Nb/AlOx/Nb junction
process was successfully operated at frequencies ranging from 6 to 10
GHz for line lengths of 0.6, 3, 6, and 9 mm. The usefulness of the
impedance transformation was then confirmed experimentally. A
propagation delay per unit length of 8.4 ps/mm was also obtained
IEEE Transactions on Appiled Superconductivity 04/2001; · 1.04 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We studied charge transport across 24°, 36°, 45°
symmetrical and 45° asymmetrical grain boundaries (GB's) in YBCO
bicrystals grown by liquid phase epitaxy (LPE). We show that transport
properties of symmetrical GB's are similar to those in bicrystals formed
by various physical vapour deposition (PVD) methods while for 45°
asymmetrical GB's, a difference between transport properties of LPE and
PVD bicrystals has been found. In particular, in contrast to PVD
bicrystals, selected LPE samples demonstrate regular magnetic
interference patterns. In an agreement with transmission electron
microscopy data, this result suggests better quality of 45°
asymmetrical GB's in LPE films
IEEE Transactions on Appiled Superconductivity 04/2001; · 1.04 Impact Factor
