Dong-Su KIM Il CHOI Sung-Il CHIEN
This paper presents a method of extracting car license plates captured from the arbitrary directions by using symmetry features. The generalized symmetry transform (GST) produces continuous features of symmetry between two points by combining locality constraint and reflectional symmetry, but its time complexity of GST is increased by the second power of the radius of a searching window. To achieve considerable reduction of this time complexity, we propose a scan line based GST (SLGST) which calculates the symmetry between a pair of edge pixels along the scan lines. Instead of calculating the global symmetry of a license plate, we assign the symmetry contribution acquired from SLGST to the corner point estimated from two edge points and their gradient orientations. The right angle tuned SLGST (RATSLGST) is newly proposed to detect the right angle corners more effectively. Image normalization by image warping is adopted to make such segmentation of license plate and later identification much easier. We also adopt the verifier that evaluates a candidate license plate to enhance extraction rate. Our experiments show that the proposed method for extracting perspectively distorted license plates is fairly reliable.
Yoshiro TAKIGUCHI Katsunori OSADA Masakazu NANBA Kazunori MIYAKAWA Saburo OKAZAKI Toshio YAMAGISHI Kenkichi TANIOKA Masahide ABE Norifumi EGAMI Mitsuru TANAKA Shigeo ITOH
To investigate the feasibility of a compact FEA image sensor with a large number of pixels, a 128 96 pixel FEA image sensor with a 4-µm-thick HARP target was fabricated and tested for the first time. The experimental results showed that the prototype could stably operate as a highly sensitive image sensor having both sufficient resolution corresponding to the number of pixels and a wide dynamic range, which demonstrated its potential as a next-generation image sensor.
Masanori SHIMADA Toshimichi SAITO
This paper presents a flexible learning algorithm for the binary neural network that can realize a desired Boolean function. The algorithm determines hidden layer parameters using a genetic algorithm. It can reduce the number of hidden neurons and can suppress parameters dispersion. These advantages are verified by basic numerical experiments.
Yukio HONDA Yoshiyuki HIRAYAMA Atsushi KIKUKAWA Masaaki FUTAMOTO
The effects of an intermediate layer of carbon on the structural and magnetic properties of a CoCrPtTa recording layer were investigated in double-layered perpendicular magnetic recording media with either amorphous CoTaZr or crystalline FeAlSi as soft magnetic backlayers. Introducing a thin layer of carbon enhanced the perpendicular magnetic anisotropy with both soft magnetic backlayers. This result suggests that the introduction of a non-magnetic intermediate layer is useful in improving the basic magnetic properties of the CoCr-alloy recording layer even when an amorphous soft magnetic backlayers is used.
Setsuo YAMAMOTO Kei HIRATA Hiroki KURISU Mitsuru MATSUURA Takanori DOI Kousaku TAMARI
Co-containing ferrite thin-film media deposited by a reactive-ECR-sputtering at a low substrate temperature of 150 degree Celsius were oxidized by ECR plasma. The magnetic properties and recording characteristics of the media were improved by the oxidation with maintaining a smooth surface. The media showed high D50 of 203 kFRPI in MIG head recording and reproduction. The Co-containing ferrite thin-film is feasible to be used as a protective overcoat layer.
Patterned magnetic media are promising to be the next generation recording media for computer hard disk drives to go beyond the density of 100 Gb/in2. A micromagnetic simulation model is set up to study the magnetic property as well as the recording process in patterned media. The patterned medium studied in this paper is an array of pillar magnetic particles with a perpendicular anisotropy. A pole record head as well as a thin film head are utilized in the simulated recording process. The diameter of the magnetic pillars is chosen as 20 nm, the bit length takes the values of 30 nm, 40 nm and 50 nm, with respect to an ideal areal density of 258 Gb/in2, 459 Gb/in2 and 717 Gb/in2. The magnetic signal and noise recorded in a series of patterned media are analyzed at different recording densities with the two types of record heads.
In recent years, perpendicular magnetic recording have progressed rapidly. It will not be long before perpendicular magnetic recording is put into practical use. However there have been few tools contributing to the optimum design of perpendicular magnetic recording media and heads except computer simulations. The authors have introduced a simple method based on the concept of self-consistent magnetization to analytically predict a transition parameter in terms of parameters of recording media and writing heads. Moreover we have discussed the origin of media noise by using a time-domain analysis of readout voltage and Voronoi cell model analysis. In this paper, main parameters to realize high bit density recording over 100 Gbit/inch2 is discussed first through these methods, and then the current status, the future problems and the prospects in perpendicular magnetic recording technology are described.
A novel technique for automatic segmentation of a brain region in single channel MR images for visualization and analysis of a human brain is presented. The method generates a volume of brain masks by automatic thresholding using a dual curve fitting technique and by 3D morphological operations. The dual curve fitting can reduce an error in curve fitting to the histogram of MR images. The 3D morphological operations, including erosion, labeling of connected-components, max-feature operation, and dilation, are applied to the cubic volume of masks reconstructed from the thresholded brain masks. This method can automatically segment a brain region in any displayed type of sequences, including extreme slices, of SPGR, T1-, T2-, and PD-weighted MR image data sets which are not required to contain the entire brain. In the experiments, the algorithm was applied to 20 sets of MR images and showed over 0.97 of similarity index in comparison with manual drawing.
Tadahiro FUJIMOTO Yoshio OHNO Kazunobu MURAOKA Norishige CHIBA
Interpolation surfaces, such as Bezier or B-spline surface, are usually used for representing smooth man-made objects and provide an excellent ability to control the shape of a surface by intuitively moving control points. In contrast, the fractal technique is used for creating various complex shapes, mainly of natural objects, that have self-similarity using simple procedures. We have proposed the "wrinkly surface (WR surface)" for combining the advantages of interpolation surfaces and fractals. In this paper, we propose the expansion of the construction scheme of the WR surface to irregular meshes. Control points of a WR surface are interpolated using the "Iterated Shuffle Transformation (IST)." Therefore, in order to achieve the expansion, we first generalize the IST on code spaces, and then propose multi-dimensional IST defined on geometric spaces. By creating various shape model examples, we demonstrate the usefulness of the WR surface as a modeling tool.
Sin-Jae KANG You-Jin CHUNG Jong-Hyeok LEE
This paper presents a method for disambiguating word senses in Korean-Japanese machine translation by using a language independent ontology. This ontology stores semantic constraints between concepts and other world knowledge, and enables a natural language processing system to resolve semantic ambiguities by making inferences with the concept network of the ontology. In order to acquire a language-independent and reasonably practical ontology in a limited time and with less manpower, we extend the existing Kadokawa thesaurus by inserting additional semantic relations into its hierarchy, which are classified as case relations and other semantic relations. The former can be obtained by converting valency information and case frames from previously-built electronic dictionaries used in machine translation. The latter can be acquired from concept co-occurrence information, which is extracted automatically from a corpus. In practical machine translation systems, our word sense disambiguation method achieved an improvement of average precision by 6.0% for Japanese analysis and by 9.2% for Korean analysis over the method without using an ontology.
While superpages are an efficient solution to increase TLB reach, strong contraint for using superpages hinders the actual utilization. Two previous solutions, a partial-subblock TLB and the shadow memory were proposed to loose the contraint. A partial-subblock TLB looses only a small portion of the contraint and limits the superpage size at a cost. The shadow memory looses most of the constraint but introduces other serious problems. We propose three novel approaches to improve superpage supports. First, we propose a hybrid scheme which integrates both the shadow memory and a partial-subblock TLB, thereby enjoying the benefits inherited from both sides. The hybrid scheme has as high a superpage utilization as the shadow memory, and avoids most of the problems in the shadow memory by the virtue of partial-subblock TLB. Second, VS-TLBs are an extension of subblock TLBs to support multiple page subblocks, while subblock TLBs can support only single page subblocks. VS-TLBs have a much larger TLB reach than subblock TLBs with a cost of a small number of bits. Last, we propose VS-hybrid which replaces the partial-subblock TLB in the hybrid scheme with a partial VS-TLB. It supports multiple page subblocks in the hybrid scheme. Therefore, it takes both advantages of the hybrid scheme and the expanded subblock size. The simulation results show that the proposed schemes take a large amount of performance gain in the benchmark application programs.
Eng Wei SOO Weiwei JIANG Lianjun WU Jian-Ping WANG
The effect of NiP as a seed layer for the [Co/Pd]n multilayer perpendicular recording media was studied. It was found that a thin layer of 2 nm NiP inserted between the FeCoC soft magnetic underlayer and the [Co/Pd]n recording layer improved the magnetic properties such as coercivity, squareness and nucleation field. These improvements may be due to the enhanced grain isolation promoted by the NiP seed layer, as well as the lower surface roughness of the NiP seed layer. Read/write test using Guzik spin stand with a ring-type head showed a D50 value 220 kFCI in the roll-off curve. The magnetic transitions recorded up to 390 kFCI for [Co/Pd]n media with the NiP seed layer can be observed clearly with MFM.
Kiyoharu HAMAGUCHI Hidekazu URUSHIHARA Toshinobu KASHIWABARA
This paper deals with formal verification of high-level designs, in particular, symbolic comparison of register-transfer-level descriptions and behavioral descriptions. We use state machines extended by quantifier-free first-order logic with equality, as models of those descriptions. We cannot adopt the classical notion of equivalence for state machines, because the signals in the corresponding outputs of such two descriptions do not change in the same way. This paper defines a new notion of consistency based on signal-transitions of the corresponding outputs, and proposes an algorithm for checking consistency of those descriptions, up to a limited number of steps from initial states. As an example of high-level designs, we take a simple hardware/software codesign. A C program for digital signal processing called PARCOR filter was compared with its corresponding design given as a register-transfer-level description, which is composed of a VLIW architecture and assembly code. Since this example terminates within approximately 4500 steps, symbolic exploration of a finite number of steps is sufficient to verify the descriptions. Our prototype verifier succeeded in the verification of this example in 31 minutes.
Jun INOUE Hideyuki SOTOBAYASHI Wataru CHUJO
A simple system configuration was used to generate transform-limited optical pulses at 160 Gbit/s in the sub-picosecond range (625 fs). Pulse compression was achieved by broadening the spectrum using supercontinuum generation followed by a linear frequency chirping compensation.
Akira ASANO Junichi ENDO Chie MURAKI
A novel method for the primitive description of the multiprimitive texture is proposed. This method segments a texture by the watershed algorithm into fragments each of which contains one grain. The similar fragments are grouped by the cluster analysis in the feature space whose basis is the morphological size density. Each primitive is extracted as the grain of the central fragment in each cluster.
To classify the significant wavelet coefficients into edge area and noise area, a morphological clustering filter applied to wavelet shrinkage is introduced. New methods for wavelet shrinkage using morphological clustering filter are used in noise removal, and the performance is evaluated under various noise conditions.
In this paper, a 3 V 8-bit 200MSPS CMOS folding/interpolation Analog-to-Digital Converter is proposed. It employs an efficient architecture whose FR (Folding Rate) is 8, NFB (Number of Folding Block) is 4, and IR (Interpolating Rate) is 8. For the purpose of improving SNR, distributed track and hold circuits are included at the front end of input stage. In order to obtain a high speed and low power operation, an improved dynamic analog latch is proposed. Further, a digital encoder based on a novel thermometer algorithm and a delay error correction algorithm is proposed. The chip has been fabricated with a 0.35 µm 2-poly 3-metal n-well CMOS technology. The effective chip area is 1200 µm 800 µm and it dissipates about 210 mW at 3 V power supply. The INL is within 1 LSB and DNL is within 1 LSB, respectively. The SNR is about 43 dB, when the input frequency is 10 MHz at 200 MHz clock frequency.
The surface film of a slip ring is important for the sliding contact phenomenon. The surface film is affected by atmospheric temperature, humidity and air pressure. The main objective of our study is to examine the effect of oxygen gas on the sliding contact phenomenon. In the present experiment, we examined the contact voltage drop for continuous sliding when the atmosphere is changed from low pressure to atmospheric pressure by introducing oxygen (O2 20%+N2 80%) or nitrogen gas. As a result, the contact voltage drop increases rapidly with increasing gas pressure, and its fluctuation also becomes large. These phenomena are observed in both cases of oxygen (O2 20%+N2 80%) and nitrogen introduction. The results clearly show that the sudden increase of contact voltage drop is affected by factors other than the oxide film. Actually, the oxide film is not formed in the nitrogen atmosphere. Furthermore, the frictional coefficient of carbon and copper ring is changed at ambient atmosphere. It is inferred from these data that the contact voltage drop may be affected by the frictional coefficient. When the gas pressure decreases again, the contact voltage drop does not suffer from the effect of ambient gas. Therefore, only the resistance of the oxide film appears to affect contact voltage drop. In this paper, the effect of sliding contact phenomenon on the contact voltage drop by gas adsorption and film generation was examined.
In this paper, we study the following problem: given two graphs G, H and an isomorphism φ between an induced subgraph of G and an induced subgraph of H, compute the number of isomorphisms between G and H that do not contradict φ. We show that this problem can be solved in O(((k+1)(k+1)!)2n3) time when the input graphs are restricted to chordal graphs with clique number at most k+1. To prove this, we first show that the tree model of a chordal graph can be uniquely constructed in O(n3) time except for the ordering of children of each node. Then, we show that the number of φ-isomorphisms between G and H can be efficiently computed by use of the tree model.
Jose H. SANTOS Naoki MATSUDA Zhi-mei QI Akiko TAKATSU Kenji KATO
The adsorption behavior of cytochrome c was investigated using slab optical waveguide (SOWG) absorption spectroscopy at the near ultraviolet region utilizing thin quartz plates as planar waveguides. SOWG absorption spectra of cytochrome c measured at constant time intervals showed significant influence of surface hydrophilicity and solution chemistry on the adsorption of this important heme protein in quartz surface. Being polar and typically amphoteric, the protein preferred adsorption on hydrophilic surface than on hydrophobic surface as implied by the lower absorbance data obtained in the latter than in the former. At lower ionic strength and in the absence of buffer, the protein molecules tend to adsorb on the quartz surface. Plots of near steady-state absorbance versus protein concentration follow hyperbolic pattern in the absence of buffer or at low ionic strength and become more linear as the buffer concentration is increased. The results presented here are explained in terms of the general qualitative understanding of protein adsorption at solid-aqueous interfaces and further aids in elucidating the properties of protein monolayers and films.