Showing papers by "NEC published in 2007"

Electronic transport in Ta2O5 resistive switch

Abstract: The authors examined the electronic transport of a solid electrolyte resistive switch. Using element analysis and the temperature dependence of its electronic transport, they deduced that the conductive path is composed of Cu metal precipitated in the solid electrolyte film by an electrochemical reaction. Furthermore, they observed Coulomb blockade phenomena at 4K when the switch was in the off state. Their observations and experimental results suggest that the metallic conductive path consists of metallic islands separated by tunneling barriers and that switching between the on and off states originates from modulation in the tunneling barriers.

Virtual Machine Management Apparatus, and Virtual Machine Management Method and Program

Abstract: A virtual machine management apparatus connected to a plurality of server devices via a network generates a new virtual machine on a server device in accordance with a request from a management terminal. At that time, for one or more server devices to which a new virtual machine can be allocated, the virtual machine management apparatus refers to an allocation rule table for storing a score for each of combinations of types of virtual machines. The score indicates appropriateness of a condition that each combination of types of virtual machines is to be allocated to the same server device. Thus, the virtual machine management apparatus computes an index value indicative of appropriateness of a condition that the new virtual machine is to be allocated to the server device. Then the virtual machine management apparatus determines an allocation target for the new virtual machine with reference to the computed index value.

Network path control system, path control device, and path control method

Abstract: A path control device includes a TE database and a local database for storing topology information showing states of use of links in a network, a topology information collection unit collecting the topology information of the respective communication nodes therefrom and updating the TE database by the topology information, a path solution unit determining a path of the network referring to the local database, an internal update unit recognizing a link included in the determined path and updating a local database by information as to said link, and an update determination unit matching the topology information of both the databases by comparing both the databases.

Role of Electronic Excitations in Ion Collisions with Carbon Nanostructures

Abstract: By combining ab initio time-dependent density functional calculations for electrons with molecular dynamics simulations for ions in real time, we investigate the microscopic mechanism of collisions between energetic protons and graphitic carbon nanostructures. We identify not only the amount of energy lost by the projectile, but also the electronic and ionic degrees of freedom of the target that accommodate this energy as a function of the impact parameter and projectile energy. Our results establish validity limits for the Born-Oppenheimer approximation and the threshold energy for defect formation in carbon nanostructures.

Quality assured network service provision system compatible with a multi-domain network and service provision method and service broker device

Abstract: The invention provides quality assured network services in a multi-domain network and comprises a network service management device for managing device clusters incorporated within the operations management network of each provider network and receiving service orders, and a multi-domain service broker for providing a broker function for achieving agreement between a plurality of providers, and the multi-domain service broker further comprises a device for collecting domain information and information relating to the services each provider is able to provide from the network service management devices, and a device which on receipt of a network service request from a customer, extracts the network service management device of the domain which is able to satisfy the required quality level, and then issues instructions for the setting of the required information within the extracted network service management device.

Semiconductor device and method of manufacturing the same

Abstract: A semiconductor device has a structure in which a light-emitting layer of an organic material or the like is sandwiched between a work function controlled single-wall carbon nanotube cathode encapsulating a donor having a low ionization potential and a work function controlled single-wall carbon nanotube anode encapsulating an acceptor having a high electron affinity. A semiconductor device represented by an organic field-effect light-emitting element and a method of manufacturing the same are provided. The semiconductor device and the method of manufacturing the same make it possible to improve characteristics and performance, such as reduction in light-emission starting voltage and a high luminous efficiency, to improve reliability, such as an increase in life, and to improve productivity, such as reduction in manufacturing cost.

Determination of the νe and total B8 solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

Abstract: This article provides the complete description of resultsfrom the Phase I data set of the Sudbury Neutrino Observatory (SNO). ThePhase I data set is based on a 0.65 kt-year exposure of heavy water tothe solar 8B neutrino flux. Included here are details of the SNO physicsand detector model, evaluations of systematic uncertainties, andestimates of backgrounds. Also discussed are SNO's approach tostatistical extraction of the signals from the three neutrino reactions(charged current, neutral current, and elastic scattering) and theresults of a search for a day-night asymmetry in the ?e flux. Under theassumption that the 8B spectrum is undistorted, the measurements fromthis phase yield a solar ?e flux of ?(?e) =1.76+0.05?0.05(stat.)+0.09?0.09 (syst.) x 106 cm?2 s?1, and a non-?ecomponent ?(? mu) = 3.41+0.45?0.45(stat.)+0.48?0.45 (syst.) x 106 cm?2s?1. The sum of these components provides a total flux in excellentagreement with the predictions of Standard Solar Models. The day-nightasymmetry in the ?e flux is found to be Ae = 7.0 +- 4.9 (stat.)+1.3?1.2percent (sys.), when the asymmetry in the total flux is constrained to bezero.

Single-Wall Carbon Nanohorns and Nanocones

Abstract: In addition to sheet structures with purely hexagonal carbon rings, whichnaturally form surfaces of zero Gaussian curvature such as sheets and tubes, agraphenic membrane can also assume a conical shape whose apex is defined by one ormore disclinations taking the form of fivefold (or possibly smaller) rings.Geometrically, just as a sheet of paper with a wedge removed can be resealed to forma conical hat, a graphene sheet with a wedge removed (i.e., a disclination) can beresealed, notionally, to form a cone or horn. The single-wall carbon nanohorns(SWNH) form one class of such conical structures, with a particularly sharp apicalangle, a well-characterized high-yield synthesis route, and a distinct aggregatemicrostructure. Conical graphenic structures with wider opening angles,corresponding to fewer pentagonal disclinations at the apex, also form, sometimes asmultilayered structures. The pentagonal defects in carbon nanocones perturb thelow-energy electronic structure both locally and globally, defining both a localregion of enhanced reactivity and a global geometric phase relation withprofound consequences for electron transport around the apex. The rapidvariation in local sheet orientation around the cone and the two-dimensionalnature of the electronic states within imply that uniform laboratory fields cangenerate highly nonuniform effective local fields for states in the cone.

Stacked film patterning method and gate electrode forming method

Abstract: A stacked film patterning method is provided which is capable of reliably removing residual substances remaining after etching of a metal film, improving etching uniformity of a silicon film, and preventing an occurrence of etching residues. A micro-crystal film and a chromium film are sequentially formed on an insulating film serving as a front-end film and the chromium film is etched to be patterned by using a resist as a mask. Next, a micro-crystal silicon film on which the residual substances exist is exposed to plasma of a mixed gas including chlorine gas and oxygen gas to selectively etch the residual substances on a surface of the micro-crystal silicon film. After that, the micro-crystal silicon film is dry etched.

Crystallization behavior and mechanical properties of bio‐based green composites based on poly(L‐lactide) and kenaf fiber

Abstract: Bio-based polymer composite was successfully fabricated from plant-derived kenaf fiber (KF) and renewable resource-based biodegradable polyester, poly(L-lactide) (PLLA), by melt-mixing technique. The effect of the KF weight contents (0, 10, 20, and 30 wt %) on crystallization behavior, composite morphology, mechanical, and dynamic mechanical properties of PLLA/KF composites were investigated. It was found that the incorporation of KF significantly improves the crystallization rate and tensile and storage modulus. The crystallization of PLLA can be completed during the cooling process from the melt at 5°C/min with the addition of 10 wt % KF. It was also observed that the nucleation density increases dramatically and the spherulite size drops greatly in the isothermal crystallization with the presence of KF. In addition, with the incorporation of 30 wt % KF, the half times of isothermal crystallization at 120°C and 140°C were reduced to 46.5% and 28.1% of the pure PLLA, respectively. Moreover, the tensile and storage modulus of the composite are improved by 30% and 28%, respectively, by the reinforcement with 30% KF. Scanning electron microscopy observation also showed that the crystallization rate and mechanical properties could be further improved by optimizing the interfacial interaction and compatibility between the KF and PLLA matrix. Overall, it was concluded that the KF could be the potential and promising filler for PLLA to produce biodegradable composite materials, owing to its good ability to improve the mechanical properties as well as to accelerate the crystallization of PLLA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Structured codebook and successive beamforming for multiple-antenna systems

Abstract: A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.

Text paraphrasing method and program, conversion rule computing method and program, and text paraphrasing system

Abstract: A paraphrase model of a question text inputted by a user is learned, and a paraphrase expression is generated in real time. When information in text set storage unit is updated, text pair extracting unit extracts a paraphrase text pair from the text set storage unit and stores it in text pair storage unit. Model learning unit learns a question text paraphrase model from the paraphrase text pair in text pair storage unit, and stores it in model storage unit. Text pair extracting unit extracts a paraphrase text pair again from the text set storage unit by using the question text paraphrase model which the model storage unit possesses, and stores it in the text pair storage unit. In case where the stored paraphrase text pair is the same as the paraphrase text pair stored in the text pair storage unit, learning of the question text paraphrase model is ended. Candidate creating unit reads the question text paraphrase model from the model storage unit and generates a paraphrase candidate of the inputted question text.

System for generating language model, method of generating language model, and program for language model generation

Abstract: A first system for generating a language model is a system for generating a language model including: a topic history dependent language model storing unit; a topic history accumulation unit; and a language score calculation unit. In the system for generating the language model, a language score corresponding to history of topics is calculated by the language score calculation unit using history of topics in an utterance accumulated in the topic history accumulation unit and a language model stored in the topic history dependent language model storing unit. The topic history dependent language model storing unit may store a topic history dependent language model dependent on only most recent n topics. The topic history accumulation unit may accumulate only most recent n topics.

Piezoelectric actuator and electronic device

Abstract: Piezoelectric actuator (60) is equipped with a piezoelectric element (10) that expands and contracts according to the state of an electric field, a pedestal (20), a vibration film (30), and a support member (40). A reinforcement member (50) is arranged in a region which acts as a node for divided vibration by piezoelectric element (10), in the divided vibration mode that occurs in high-frequency bands. One or more reinforcement members (50) are selectively arranged on the front or back of the piezoelectric element (10). Since the vibration mode of piezoelectric element (10) can be changed with this configuration, divided vibration, which is a source of hills and valleys (peaks and dips) in frequency acoustic pressure level characteristics, can be efficiently suppressed. Therefore, it is possible to realize flat frequency acoustic pressure level characteristics and reproduce high-quality sound.

Cluster system, load distribution method, optimization client program, and arbitration server program

Abstract: An exemplary cluster system according to the present invention includes a first node including a plurality of paths respectively connected to I/O slots via a switch and a second node including a plurality of paths connected to the switch, wherein the first node includes a first load measuring part which measures a first load for each path thereof, and the switch makes switching to disconnect an I/O slot from the first node and connect the I/O slot to the second node when the first load of the path connected to the I/O slot is higher than a first threshold.

Cationic Polymerization of Poly(vinyl ether) Bearing a TEMPO Radical: A New Cathode-Active Material for Organic Radical Batteries

Abstract: PTVE was synthesized as a new active material for organic radical batteries. Cationic polymerization of a monomer bearing a TEMPO radical moiety took place. The spin concentration of PTVE was estimated to be 2.75 × 10 21 spins · g -1 (100% spin per repeating unit). The PTVE is extremely stable; there is no decrease in spin concentration when storing PTVE samples for more than a year under aerobic conditions at room temperature. The redox potential of PTVE is 3.55 V (vs. Li/Li + ). A coin-type cell using a PTVE/VGCF composite electrode was also fabricated, and then performed charge/discharge measurements. The discharge capacity of PTVE is 114 mAh ·g -1 (84% of the theoretical value).

Information Recording System, Information Recording Device, Information Recording Method, and Information Collecting Program

Abstract: Accident determination means (105) determines, based on a detection signal from an impact sensor (104), whether an accident has occurred. When it is determined that an accident has occurred, an image evacuation means (106) extracts, from a ring buffer (103), images taken in several seconds before and after the occurrence of the accident and evacuates the images to a storage memory (107). Also, when it is determined that an accident has occurred, image recording request means (108) sends an image recording request to a drive recorder (10) of a subject vehicle present in the vicinity of the accident site. When image evacuation means (106) of the drive recorder (10) of the subject vehicle receives the image recording request, the image evacuation means (106) extracts images from the ring buffer (103), the images being those taken in several seconds before and after the occurrence of the accident, and evacuates the extracted images to a storage memory (107).

Semiconductor integrated circuit device

Abstract: Wiring is routed to assure insulation between wiring traces in a semiconductor integrated circuit device. The device includes a first wiring trace to which a prescribed voltage is supplied; a second wiring trace that takes on a voltage that exceeds the prescribed voltage; and a third wiring trace that only takes on a voltage less than the prescribed voltage. Alternatively, the device includes a first wiring trace to which a prescribed voltage is supplied; a second wiring trace that takes on a voltage less than the prescribed voltage; and a third wiring trace that takes on a voltage equal to or greater than the prescribed voltage. The wiring traces are routed at a certain wiring space in such a manner that the first wiring trace is interposed between the second and third wiring traces. The first wiring trace for which the potential difference is known to be small beforehand is routed so as to always be adjacent to the second wiring trace. Accordingly, the third wiring trace for which there is the possibility that the potential difference relative to the second wiring trace will become large is never placed directly adjacent the second wiring trace. As a result of such routing, wiring is implemented in such a manner that the insulation between traces can be sufficiently assured.

A 1 Tb/s 3 W Inductive-Coupling Transceiver for 3D-Stacked Inter-Chip Clock and Data Link

Abstract: A 1 Tb/s 3 W inter-chip transceiver transmits clock and data by inductive coupling at a clock rate of 1 GHz and data rate of 1 Gb/s per channel. 1024 data transceivers are arranged with a pitch of 30 mum in a layout area of 1 mm2. The total layout area including 16 clock transceivers is 2 mm2 in 0.18 mum CMOS and the chip thickness is reduced to 10 mum. Bi-phase modulation (BPM) is employed for the data link to improve noise immunity, reducing power in the transceiver. Four-phase time division multiple access (TDMA) reduces crosstalk and the bit-error rate (BER) is lower than 10-13

Method of designing a pattern

Abstract: A method of designing a pattern of a hole pattern having a configuration, in which grid of interval smaller than a minimum permissible pitch according to a design rule for a semiconductor integrated circuit is provided in a pattern drawing, a hole pattern is arranged on a first lattice point which is an intersection of the grid, and, at the same time, other hole patterns are not arranged on a second lattice point group which is on the periphery of the first lattice point, and is adjacent to the first lattice point is provided. And, the number of hole patterns, which may be arranged in a third lattice point group of a plurality of lattice points which are on the periphery of a second lattice point group and are within a predetermined distance from the first lattice point, is controlled.

System and method for providing wireless over a passive optical network (PON)

Abstract: A network system and method include a wireless base station integrated at a central office of a service provider. The wireless base station is configured to provide portable and fixed services to customers. A passive optical network is coupled to the wireless base station at the central office to provide a link to extend an antenna for wireless operations of the wireless base station to a remote site such that a wireless signal from the wireless base station is transmitted in parallel with a passive fiber network signal through the link.

Supervised consensus scoring for docking and virtual screening.

Abstract: Docking programs are widely used to discover novel ligands efficiently and can predict protein-ligand complex structures with reasonable accuracy and speed. However, there is an emerging demand for better performance from the scoring methods. Consensus scoring (CS) methods improve the performance by compensating for the deficiencies of each scoring function. However, conventional CS and existing scoring functions have the same problems, such as a lack of protein flexibility, inadequate treatment of salvation, and the simplistic nature of the energy function used. Although there are many problems in current scoring functions, we focus our attention on the incorporation of unbound ligand conformations. To address this problem, we propose supervised consensus scoring (SCS), which takes into account protein-ligand binding process using unbound ligand conformations with supervised learning. An evaluation of docking accuracy for 100 diverse protein-ligand complexes shows that SCS outperforms both CS and 11 scoring functions (PLP, F-Score, LigScore, DrugScore, LUDI, X-Score, AutoDock, PMF, G-Score, ChemScore, and D-score). The success rates of SCS range from 89% to 91% in the range of rmsd < 2 A, while those of CS range from 80% to 85%, and those of the scoring functions range from 26% to 76%. Moreover, we also introduce a method for judging whether a compound is active or inactive with the appropriate criterion for virtual screening. SCS performs quite well in docking accuracy and is presumably useful for screening large-scale compound databases before predicting binding affinity.

Covalent Functionalization of Carbon Nanohorns with Porphyrins: Nanohybrid Formation and Photoinduced Electron and Energy Transfer

Abstract: The covalent attachment of carbon nanohorns (CNHs) to α-5-(2-aminophenyl)-α-15-(2-nitrophenyl)-10,20-bis(2,4,6-trimethyl-phenyl)-porphyrin (H2P) via an amide bond is accomplished. The resulting CNH–H2P nanohybrids form a stable inklike solution. High-resolution transmission electron microscopy (HRTEM) images demonstrate that the original dahlia-flowerlike superstructure of the CNHs is preserved in the CNH–H2P nanohybrids. Steady-state and time-resolved fluorescence studies show efficient quenching of the excited singlet state of H2P, suggesting that both electron and energy transfer occur from the singlet excited state of H2P to CNHs, depending on the polarity of the solvent. In the case of electron transfer, photoexcitation of H2P results in the reduction of the nanohorns and the simultaneous oxidation of the porphyrin unit. The formation of a charge-separated state, CNH•––H2P•+, has been corroborated with the help of an electron mediator, hexyl-viologen dication (HV2+), in polar solvents. Moreover, the charge-separated CNH•––H2P•+ states have been identified by transient absorption spectroscopy.

Using LDPC-Coded Modulation and Coherent Detection for Ultra Highspeed Optical Transmission

Abstract: We propose the coded modulation schemes for ultrahigh-speed transmission (100 Gb/s and above) by using commercially available components operating at 40 gigasymbols/s. The bit-interleaved coded modulation in combination with the low-density parity-check codes that are used as component codes has been applied. The modulation is based on either M-ary quadrature-amplitude modulation or M-ary phase-shift keying. bits are mapped into the corresponding signal constellation point using either Gray or natural mapping. The coherent detection scheme has been found to outperform the direct detection one and to provide an additional margin much needed for longer transmission distances or for application in an all-optical network scenario.

Semiconductor device, manufacturing method and apparatus for the same

Abstract: A highly reliable semiconductor chip electrode structure allowing control of interface reaction of bonding sections even in the case of using two- or three-element solder used conventionally is disclosed. A solder alloy making layer for preventing dissolving and diffusion of tin into tin-based lead free solder is thinly formed on a UBM layer. The tin-based solder is supplied in solder paste or solder ball form. A combined solder alloy layer composed of a combination of intermetallic compounds, one of tin and the solder alloy making layer, and one of tin and the UBM layer, is formed by heating and melting.