Showing papers by "NEC published in 2004"

On-Line Unsupervised Outlier Detection Using Finite Mixtures with Discounting Learning Algorithms

Abstract: Outlier detection is a fundamental issue in data mining, specifically in fraud detection, network intrusion detection, network monitoring, etc. SmartSifter is an outlier detection engine addressing this problem from the viewpoint of statistical learning theory. This paper provides a theoretical basis for SmartSifter and empirically demonstrates its effectiveness. SmartSifter detects outliers in an on-line process through the on-line unsupervised learning of a probabilistic model (using a finite mixture model) of the information source. Each time a datum is input SmartSifter employs an on-line discounting learning algorithm to learn the probabilistic model. A score is given to the datum based on the learned model with a high score indicating a high possibility of being a statistical outlier. The novel features of SmartSifter are: (1) it is adaptive to non-stationary sources of datas (2) a score has a clear statistical/information-theoretic meanings (3) it is computationally inexpensives and (4) it can handle both categorical and continuous variables. An experimental application to network intrusion detection shows that SmartSifter was able to identify data with high scores that corresponded to attacks, with low computational costs. Further experimental application has identified a number of meaningful rare cases in actual health insurance pathology data from Australia's Health Insurance Commission.

Security as a new dimension in embedded system design

Abstract: The growing number of instances of breaches in information security in the last few years has created a compelling case for efforts towards secure electronic systems. Embedded systems, which will be ubiquitously used to capture, store, manipulate, and access data of a sensitive nature, pose several unique and interesting security challenges. Security has been the subject of intensive research in the areas of cryptography, computing, and networking. However, despite these efforts, security is often mis-construed by designers as the hardware or software implementation of specific cryptographic algorithms and security protocols. In reality, it is an entirely new metric that designers should consider throughout the design process, along with other metrics such as cost, performance, and power..This paper is intended to introduce embedded system designers and design tool developers to the challenges involved in designing secure embedded systems. We attempt to provide a unified and holistic view of embedded system security by first analyzing the typical functional security requirements for embedded systems from an end-user perspective. We then identify the implied challenges for embedded system architects, as well as hardware and software designers (e.g., tamper-resistant embedded system design, processing requirements for security, impact of security on battery life for battery-powered systems, etc.). We also survey solution techniques to address these challenges, drawing from both current practice and emerging research, and identify open research problems that will require innovations in embedded system architecture and design methodologies.

A nonvolatile programmable solid electrolyte nanometer switch

Abstract: A reconfigurable LSI employing a nonvolatile nanometer-scale switch, NanoBridge, is proposed, and its basic operations are demonstrated. The switch, composed of solid electrolyte copper sulfide, has a <30-nm contact diameter and <100-/spl Omega/ on-resistance. Because of its small size, it can be used to create extremely dense field-programmable logic arrays. A 4 /spl times/ 4 crossbar switch and a 2-input look-up-table circuit are fabricated with 0.18-/spl mu/m CMOS technology, and operational tests with them have confirmed the switch's potential for use in programmable logic arrays. A 1-kb nonvolatile memory is also presented, and its potential for use as a low-voltage memory device is demonstrated.

Router and network connecting method

Abstract: Route information used for dynamic route control can be shared by an active router and a standby router even in normal operation. After route calculation is performed according to a routing protocol, the calculated route information can be shared, enabling efficient operation. Protocol engine sections (31a to 31d) communicate with routers (41, 42), calculate a route to be selected for the routing according to the corresponding protocol. When the route information is altered, a route sharing information transmitting section (33) transmits the route information to the standby router. The protocol engine section in each router acting as an active router communicates with the router (41, 42), calculates a route to be selected for the routing according to the corresponding protocol, and transmits the route information, if it is altered. A route sharing information receiving section (34) receives the route information.

Collecting evaluative expressions for opinion extraction

Abstract: Automatic extraction of human opinions from Web documents has been receiving increasing interest. To automate the process of opinion extraction, having a collection of evaluative expressions such as “something is confortable” would be useful. However, it can be costly to manually create an exhaustive list of such expressions for many domains, because they tend to be domain-dependent. Motivated by this, we explored ways to accelerate the process of collecting evaluative expressions by applying a text mining technique. This paper proposes a semi-automatic method that uses particular cooccurrence patterns of evaluated subjects, focused attributes and value expressions.

k-Times Anonymous Authentication (Extended Abstract)

Abstract: We propose an authentication scheme in which users can be authenticated anonymously so long as times that they are authenticated is within an allowable number. The proposed scheme has two features that allow 1) no one, not even an authority, identify users who have been authenticated within the allowable number, and that allow 2) anyone to trace, without help from the authority, dishonest users who have been authenticated beyond the allowable number by using the records of these authentications. Although identity escrow/group signature schemes allow users to be anonymously authenticated, the authorities in these schemes have the unnecessary ability to trace any user. Moreover, since it is only the authority who is able to trace users, one needs to make cumbersome inquiries to the authority to see how many times a user has been authenticated. Our scheme can be applied to e-voting, e-cash, electronic coupons, and trial browsing of content. In these applications, our scheme, unlike the previous one, conceals users’ participation from protocols and guarantees that they will remain anonymous to everyone.

Electromagnetic interference (EMI) of system-on-package (SOP)

Abstract: Electromagnetic interference (EMI) issues are expected to be crucial for next-generation system-on-package (SOP) integrated high-performance digital LSIs and for radio frequency (RF) and analog circuits. Ordinarily in SOPs, high-performance digital LSIs are sources of EMI, while RF and analog circuits are affected by EMI (victims). This paper describes the following aspects of EMI in SOPs: 1) die/package-level EMI; 2) substrate-level EMI; 3) electromagnetic modeling and simulation; and 4) near electromagnetic field measurement. First, LSI designs are discussed with regard to radiated emission. The signal-return path loop and switching current in the power/ground line are inherent sources of EMI. The EMI of substrate, which work as coupling paths or unwanted antennas, is described. Maintaining the return current path is an important aspect of substrate design for suppressing EMI and for maintaining signal integrity (SI). In addition, isolating and suppressing the resonance of the DC power bus in a substrate is another important design aspect for EMI and for power integrity (PI). Various electromagnetic simulation methodologies are introduced as indispensable design tools for achieving high-performance SOPs without EMI problems. Measurement techniques for near electric and magnetic fields are explained, as they are necessary to confirm the appropriateness of designs and to investigate the causes of EMI problems. This paper is expected to be useful in the design and development of SOPs that take EMI into consideration.

Spectroscopic characterization of Stone-Wales defects in nanotubes

Abstract: We combined resonant photoabsorption and vibration spectroscopy with scanning tunneling microscopy ~STM! to unambiguously identify the presence of Stone-Wales ~SW! defects in carbon and boron nitride nanotubes. Based on extensive time-dependent ab initio density functional calculations, we propose to resonantly photoexcite SW defects in the infrared and ultraviolet regime as a means of their identification. Onset of nonradiative decay to a local defect vibration with a frequency of 1962 cm 21 serves as a fingerprint of such defects in carbon nanotubes. The bias dependence of the STM images shows distinct features associated with the presence of SW defects.

Mobile terminal, method of controlling the same, and computer program of the same

Abstract: A mobile telephone ( 1 ), when being folded, is set in a lock state by an opening/closing detection and lock mechanism ( 50 ), and then a control circuit ( 30 ) stops supply of an electric power to a fingerprint authentication unit ( 60 ) In this state, upon detection of an incoming call from an external apparatus, the control circuit ( 30 ) restarts the supply of the electric power to the fingerprint authentication unit ( 60 ), and when a user is authenticated as a legitimate user by the fingerprint authentication unit ( 60 ), instructs the opening/closing detection and lock mechanism ( 50 ) to carry out an unlocking operation

Method for providing layout design and photo mask

Abstract: A method for providing the layout design of semiconductor integrated circuit that is capable of promoting the reduction of the circuit pattern area is provided. A hole pattern is disposed at the mesh point which is an intersecting point of mutually orthogonal virtual grid lines and another hole pattern is not disposed at the adjacent mesh point that is the mostly closed mesh point having the hole pattern thereon.

Fingerprint apparatus and method

Abstract: A fingerprint input apparatus includes an image sensor which responds to scattered light emanating from a finger. The scattered light is generated inside a finger having a fingerprint pattern in accordance with external light. The sensor may be a two-dimensional image sensor made of a large number of light-receiving elements arranged in a two-dimensional array or a one-dimensional sensor made of a large number of light-receiving elements arranged in a line-type array. In the latter case, the fingerprint is input by swiping the finger across the image sensor and reconstructing the fingerprint image. The fingerprint input apparatus is used to control use of a variety of devices, including electronic devices such as cellular telephones and personal computers, and access to buildings, rooms, safes and the like. The fingerprint input apparatus makes possible the elimination of personal identification numbers (PINs) and signatures in a variety of transactions.

Accurate analysis of two-dimensional electromagnetic scattering from multilayered periodic arrays of circular cylinders using lattice sums technique

Abstract: A very efficient and accurate method to characterize two-dimensional (2-D) electromagnetic scattering from multilayered periodic arrays of parallel circular cylinders is presented, using the lattice sums technique, the aggregate T-matrix algorithm, and the generalized reflection and transmission matrices for a layered system. The method is quite general and applies to various configurations of 2-D periodic arrays. The unit cell of the array can contain two or more cylinders, which may be dielectric, conductor, gyrotropic medium, or their mixture with different sizes. The periodic spacing of cylinders along each array plane should be the same over all layers, but otherwise the cylinders in different layers may be different in material properties and dimensions. The numerical examples validate the usefulness and accuracy of the proposed method.

Apparatus and method for communication

Abstract: A communication apparatus and a communication method realizing highly amusing features and merchantability. A face image of the sender of a text message changes according to the contents of the message, especially symbols, marks and the like which indicate an emotional state in the message. Thereby, an image suitable for each symbol, mark or the like which indicates an emotional state in the text message is selectively displayed on a screen. Thus, the user of a communication apparatus can immediately understand sender's feeling without reading all the text message.

Alteration of chromosome positioning during adipocyte differentiation.

Abstract: Chromosomes are highly restricted to specific chromosome territories within the interphase nucleus The arrangement of chromosome territories is non-random, exhibiting a defined radial distribution as well as a preferential association with specific nuclear compartments, which indicates a functional role for chromosome-territory organization in the regulation of gene expression In this report, we focus on changes in adipocyte differentiation that are related to a specific chromosomal translocation associated with liposarcoma tumorigenesis, t(12;16) We have examined the relative and radial positioning of the chromosome territories of human chromosomes 12 and 16 during adipocyte differentiation, and detected a close association between the territories of chromosomes 12 and 16 in differentiated adipocytes, an association not observed in preadipocytes Although further studies are required to elucidate the underlying reasons for the adipocyte-specific translocation of chromosomes 12 and 16, our observations indicate that alteration of relative chromosome positioning might play a key role in the tumorigenesis of human liposarcomas In addition, these results demonstrate the potential impact of higher order chromatin organization on the epigenetic mechanisms that control gene expression and gene silencing during cell differentiation

Tracking dynamics of topic trends using a finite mixture model

Abstract: In a wide range of business areas dealing with text data streams, including CRM, knowledge management, and Web monitoring services, it is an important issue to discover topic trends and analyze their dynamics in real-time. Specifically we consider the following three tasks in topic trend analysis: 1)Topic Structure Identification; identifying what kinds of main topics exist and how important they are, 2)Topic Emergence Detection; detecting the emergence of a new topic and recognizing how it grows, 3)Topic Characterization; identifying the characteristics for each of main topics. For real topic analysis systems, we may require that these three tasks be performed in an on-line fashion rather than in a retrospective way, and be dealt with in a single framework. This paper proposes a new topic analysis framework which satisfies this requirement from a unifying viewpoint that a topic structure is modeled using a finite mixture model and that any change of a topic trend is tracked by learning the finite mixture model dynamically. In this framework we propose the usage of a time-stamp based discounting learning algorithm in order to realize real-time topic structure identification. This enables tracking the topic structure adaptively by forgetting out-of-date statistics. Further we apply the theory of dynamic model selection to detecting changes of main components in the finite mixture model in order to realize topic emergence detection. We demonstrate the effectiveness of our framework using real data collected at a help desk to show that we are able to track dynamics of topic trends in a timely fashion.

Location system and method for operating mobile terminal as a responsible location for selecting a positioning method

Abstract: In a mobile communication network, a controlling node receives capability information from a mobile terminal, indicating positioning methods supported by the mobile terminal and selectability of the positioning methods. In response to a location request message from a client terminal requesting the location information of a target mobile terminal, the controlling node transmits a first control message via a wireless node to the target mobile terminal, containing a copy of requested accuracy of the location information, if the capability information indicates that the target mobile terminal is capable of selecting positioning methods. The mobile terminal performs measurement according to a positioning method that satisfies the requested accuracy. Otherwise, the controlling transmits a second control message to the mobile terminal, specifying a positioning method. In this case, the mobile terminal performs measurement according to the specified positioning method.

VirtualScan: a new compressed scan technology for test cost reduction

Abstract: This work describes the VirtualScan technology for scan test cost reduction. Scan chains in a VirtualScan circuit are split into shorter ones and the gap between external scan ports and internal scan chains are bridged with a broadcaster and a compactor. Test patterns for a VirtualScan circuit are generated directly by one-pass VirtualScan ATPG, in which multi-capture clocking and maximum test compaction are supported. In addition, VirtualScan ATPG avoids unknown-value and aliasing effects algorithmically without adding any additional circuitry. The VirtualScan technology has achieved successful tape-outs of industrial chips and has been proven to be an efficient and easy-to-implement solution for scan test cost reduction.

Name resolution server and packet transfer device

Abstract: The DNS server according to the present invention includes a user information identification unit which identifies an attribute of a user who has transmitted a DNS query message through a user information obtaining unit and handing over an identification result to a response generation unit, a user information obtaining unit for referring to a user information database to obtain user attribute information of a user who has transmitted a DNS query message, and a response generation unit for searching a response database for a name resolution method relevant to user attribute information handed over from the user information identification unit to conduct name resolution according to the found name resolution method, thereby enabling name resolution to be minutely customized for each attribute of a user.

A generalized proportionate variable step-size algorithm for fast changing acoustic environments

Abstract: This paper proposes a generalized proportionate variable step-size algorithm based on affine projection. It controls the step size for each tap individually based on the gradient approximated by the difference between the current coefficient and an averaged filter coefficient with delay. This step-size control is specifically effective for tracking fast changing acoustic environments. It is shown that the P-NLMS family and the ES algorithm are special cases of the proposed algorithm in terms of step-size control. Simulation results in the context of echo cancellation in artificial and real environments demonstrate that this step-size control combined with the affine projection algorithm (APA) reduces the echo by up to 5 dB compared to the standard APA. The best tracking performance, without a priori knowledge on the acoustic environment, among the same family of algorithms is obtained.

Group-III nitride semiconductor device

Abstract: A method of forming a partially etched nitride-based compound semiconductor crystal layer includes the following steps. A non-crystal layer of a nitride-based compound semiconductor is formed. At least a part of the non-crystal layer is then etched to form a partially etched non-crystal layer before the partially etched non-crystal layer is crystallized to form a partially etched nitride-based compound semiconductor crystal layer.

Electronic ticket issuing system and electronic ticket issuing method

Abstract: An electronic ticket issuing system and an electronic ticket issuing method for simplifying authentication procedures by the use of biological information such as a fingerprint and voiceprint First, a ticket buyer sends a request for ticket purchase to a ticket issuing center using his/her mobile terminal The ticket issuing center transmits a request for issue of an electronic certificate to request an authentication department to issue an electronic certificate The authentication department creates an electronic certificate to which the biological information about the ticket buyer is added The ticket issuing center transmits an electronic ticket including the electronic certificate to the mobile phone When the ticket buyer participates in an event with the electronic ticket, the ticket buyer transmits the electronic ticket with the biological information to an authentication terminal In addition, the ticket buyer inputs his/her biological information at the moment into the authentication terminal Subsequently, the authentication terminal compares the two pieces of biological information for authentication Since the electronic ticket includes the biological information, the authentication terminal can perform high-security authentication without exchanging the biological information with the authentication department via a network

Improved power performance for a recessed-gate AlGaN-GaN heterojunction FET with a field-modulating plate

Abstract: A recessed-gate AlGaN-GaN field-modulating plate (FP) field-effect transistor (FET) was successfully fabricated on an SiC substrate. By employing a recessed-gate structure on an FP FET, the transconductance was increased from 150 to 270 mS/mm, leading to an improvement in gain characteristics, and current collapse was minimized. At 2 GHz, a 48-mm-wide recessed FP FET exhibited a record output power of 230 W (4.8 W/mm) with 67% power-added efficiency and 9.5-dB linear gain with a drain bias of 53 V.

Tetraspanin protein (TSP-15) is required for epidermal integrity in Caenorhabditis elegans

Abstract: Epidermal integrity is essential for animal development and survival. Here, we demonstrate that TSP-15, a member of the tetraspanin protein family, is required for epithelial membrane integrity in Caenorhabditis elegans. Reduction of tsp-15 function by mutation or by RNA interference elicits abnormalities of the hypodermis, including dissociation of the cuticle and degeneration of the hypodermis. Lethality during molting often results. Examination of GFP transgenic animals, genetic mosaic analysis and rescue assays revealed that TSP-15 functions in hyp7, a large syncytium that composes most of the hypodermis. Assays with a membrane-impermeable dye or leakage analysis of a hypodermal-specific marker indicate that the barrier function of the hypodermal membrane is impaired owing to the loss or reduction of TSP-15. These results indicate that TSP-15 functions in the maintenance of epithelial cell integrity.

Operation limiting technique for a camera-equipped mobile communication terminal

Abstract: A camera-equipped mobile communication terminal allows its own camera functions to be selectively inhibited according to camera-function inhibition flags included in a camera-function limiting signal broadcast by a radio station or based on GPS-measured location and camera-function inhibition flags for each operation-limited area. Appropriate function limitations on the camera-equipped mobile communication terminal and necessary function permissions can be made depending on situations or occasions.

Compact semiconductor device capable of mounting a plurality of semiconductor chips with high density and method of manufacturing the same

Abstract: In a semiconductor device, rewirings 3 for connecting a semiconductor chip 1 a , a semiconductor chip 1 b and external connecting terminals 4 with each other are formed on the semiconductor chip 1 a An insulating resin 6 having opening portions in regions for forming the external connecting terminals 4 at peripheral portion of the semiconductor chip 1 a and another opening portions in another region for mounting the semiconductor chip 1 b at the central of the semiconductor chip 1 a is overlaid on the rewirings 3 The external connecting terminals 4 consisting of BGA are formed in the opening portions of the regions for forming the external connecting terminals 4 through lands 5 The semiconductor chip 1 b is connected to another opening portions of another region for mounting the semiconductor chip 1 b by flip-chip structure through electrodes 11 and bumps 8 A junction surface of the bumps 8 is sealed by a sealing resin 7 The semiconductor chip 1 b is mounted on the same surface as that the external connecting terminals 4 are formed The under surface of the semiconductor chip 1 b is ground in order that the semiconductor chip 1 b may be shorter than the external connecting terminals 4 The semiconductor chip 1 b is thereby mounted with high density

Single-photon interference over 150 km transmission using silica-based integrated-optic interferometers for quantum cryptography

Abstract: We have demonstrated single-photon interference over 150 km using time-division interferometers for quantum cryptography, which were composed of two integrated-optic asymmetric Mach-Zehnder interferometers, and balanced gated-mode photon detectors. The observed fringe visibility was more than 80% after 150 km transmission.

Location sensing system and method using packets asynchronously transmitted between wireless stations

Abstract: In a communication system, a location server is provided for receiving a location request. A plurality of base stations whose locations are predetermined are connected to the location server. In response to the location request, the system determines a round-trip propagation delay time of packets asynchronously transmitted over a wireless channel between each of the base stations and a target mobile station, calculates the distances from the round-trip propagation delay times, and estimates the location of the mobile station from an intersection of a plurality of circles whose radii are equal to the distances and whose centers respectively coincide with the locations of the base stations. The location server returns a location report to the requesting source for indicating the location of the mobile station.

Selective deposition of a gadolinium(III) cluster in a hole opening of single-wall carbon nanohorn

Abstract: Selective synthesis of particles of angstrom to nanometer size consisting of one to many metal atoms is instrumental in various applications, but it has been hampered by the tendency of the metal atom to form large clusters. We found, as studied by the state-of-the-art electron microscopic technique, a strategy to produce metal-containing nanoparticles isolated from each other by depositing metal atoms in a hydrophilic hole on or in the interior of a carbon nanotube as demonstrated by the reaction of Gd(OAc)3 with oxidized single-wall nanohorns. Besides the potential utilities of the deposited metal clusters, the metal deposition protocol provides a method to control permeation of molecules through such openings.