Artificial retina chips for image processing

Artificial retina chips which can simultaneously sense and process real world images are described. The comparison between artificial retinal systems and conventional image processing systems is described. Variable sensitivity photodetection, which is an essential technology for the artificial retina chips, is introduced in detail. The concept, structure, fundamental performance, operating principle, and processing functions for the fabricated artificial retinal chips are described. Applications including interactive games by gesture-input are also introduced. This work was presented, in part, at the International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1996.     

Delay time compensation based on coefficient of restitution for collision hybrid motion simulator

A hybrid motion simulator embeds a hardware experiment in a numerical simulation loop. However, it is often subjected to the inherent problem of an energy increase in the collision of two pieces of hardware in a loop because of the delay time. This paper proposes a delay time compensation method based on contact dynamics model for a collision hybrid motion simulator under delay time and establishes a compensation method for coupled translational and rotational motion. The model developed in this paper describes linear uniform motion of a floating object during the period of the delay time until the force and torque are observed and non-linear motion according to environmental stiffness after the initial delay time period in contact. By using the above model, compensation parameters are designed based on desired coefficient of restitution with iterative calculation. The proposed method achieves accurate delay time compensation and simultaneously realizes a variable desired coefficient of restitution over a wide range of frequencies. Furthermore, the compensation method for multi-dimensional motion is established under the assumption that the friction effect is very small. The efficiency of the proposed method is verified through collision experiments for the coupled motion in two dimensions.     

In-plane detection of scattered light from a minute particle using a resin-based light waveguide incorporated with a microfluidic channel

An optical sensor combined total analysis system (TAS) is thought to be one of the most powerful functional elements needed to realize a “ubiquitous human healthcare” system. In accordance with this concept, we have proposed a fundamental structure of detecting side scattered light from a minute cell or particle running along a microfluidic channel, partially utilizing the channel filled with water or saline solution as a light waveguide. Based on this concept, we have fabricated a trial-manufactured optical TAS chip and carefully evaluated its side scattered light measuring performance in in-plane direction, supplying and detecting visible laser power by using multiple optical fibers and their precise positioning mechanisms. We have successfully obtained experimental results of both transmitted light power change and that of side scattered light, and we confirmed that there was a strong relationship between their signal waveforms. Furthermore, we have developed a hybrid numerical calculation method on the basis of the finite-difference time-domain method, in addition to the beam propagation method. Based on this hybrid method, we tried to compare results between the experimental inverse pulse of transmitted light and a pulse of side scattered light, and those based on numerical calculations. Excellent qualitative accordance was obtained between the inverse pulse of numerical and experimental results. In contrast, the experimental pulse of side scattered light indicated a considerably spread base in comparison to the numerical results.     

A Form Evaluation System and Its Data Structure for Brush-Written Chinese Characters

1IntroductionCharacterswerecreatedasamediumofcommunication.Forexample,theyhavebeenusedtorecordsocialactivitiesandhumanthinking,andtohelppeoplesexchangeinformation.Differencesfrommanyothercharacters,however,theChi-nesecharacterisatypicalideograph.BecauseChinesecharactersoriginatedfromdrawings,theirshapeshavetheelementsofbeauty.InChina,calligraphyaboutChinesecharactershasbeenanimportanpartofartsinceancienttimes.There-sultsofstudiesaboutcalligraphyhavebeenbequeathedascalligraphicworksandcallig…     

Chained aggregation model with minimum truncation error

A reduced–order model for a multi–input single–output or a single–input multi–output continuous system is proposed. The model is especially suitable for the case where accuracy in the high-frequency region is important. It also satisfies basic conditions for reduced-order models, such as uniqueness, stability, and a simple calculation requirement. Chained aggregation with the minimization of truncation errors introduces an internal system representation characterized by a system matrix of Hessenberg form and a diagonalized covariance matrix.     

Detection of fluorescence from a mixed specimen consisting of micro particles attached to different fluorescent substances using a light waveguide incorporated optical TAS

A “ubiquitous human health care system” will require a monolithic optical total analysis system (TAS) consisting of waveguides and microfluidic channels based on a transparent resin chip. Together with the rapid development of the fluorescent marking method, fluorescence analysis by TAS of mixed-microparticle specimen attached to different fluorescent substances will be necessary. Towards realization of this, we here propose a novel method for using a part of the fluorescence acquired by irradiating microparticles with AC-modulated laser power as light dedicated to the discrimination of fluorescent substances. Since the light power for discrimination was extremely weak, we extracted effective signal components using a lock-in detection method. Then, by comparison with the signal of the original fluorescence, we could determine whether the fluorescence signal was from the microparticles attached to the fluorescent substance to be discriminated. Using a mixed specimen composed of microparticle-attached fluorescent substances with emission peaks of 520 nm and 600 nm, we found that 10% of the acquired fluorescence could successfully determine the specified fluorescent substance as a discrimination signal. The peak value of the discrimination signal was approximately double the amplitude of the stationary noise in the discrimination signal.

     

Formation of the myosin.ADP.gallium fluoride complex and its solution structure by small-angle synchrotron X-ray scattering

The products of the SOS-regulated umuDC operon are required for most UV and chemical mutagenesis in Escherichia coli, a process that results from a translesion synthesis mechanism. The UmuD protein is activated for its role in mutagenesis by a RecA-facilitated autodigestion that removes the N-terminal 24 amino acids. A previous genetic screen for nonmutable umuD mutants had resulted in the isolation of a set of missense mutants that produced UmuD proteins that were deficient in RecA-mediated cleavage (J. R. Battista, T. Ohta, T. Nohmi, W. Sun, and G. C. Walker, Proc. Natl. Acad. Sci. USA 87:7190-7194, 1990). To identify elements of the UmuD' protein necessary for its role in translesion synthesis, we began with umuD', a modified form of the umuD gene that directly encodes the UmuD' protein, and obtained missense umuD' mutants deficient in UV and methyl methanesulfonate mutagenesis. The D39G, L40R, and T51I mutations affect residues located at the UmuD'2 homodimer interface and interfere with homodimer formation in vivo. The D75A mutation affects a highly conserved residue located at one end of the central strand in a three-stranded beta-sheet and appears to interfere with UmuD'2 homodimer formation indirectly by affecting the structure of the UmuD' monomer. When expressed from a multicopy plasmid, the L40R umuD' mutant gene exhibited a dominant negative effect on a chromosomal umuD+ gene with respect to UV mutagenesis, suggesting that the mutation has an effect on UmuD' function that goes beyond its impairment of homodimer formation. The G129D mutation affects a highly conserved residue that lies at the end of the long C-terminal beta-strand and results in a mutant UmuD' protein that exhibits a strongly dominant negative effect on UV mutagenesis in a umuD+ strain. The A30V and E35K mutations alter residues in the N-terminal arms of the UmuD'2 homodimer, which are mobile in solution.     

Void formation mechanism in VLSI aluminum metallization

Void formation is aluminum lines caused by high-temperature heat treatment has been investigated, particularly from the aspect of mechanical interaction between the passivation layer and aluminum lines. It is found that there are two effects causing voids in aluminum lines: the deformation of the passivation layer and the so-called thermal expansion mismatch between aluminum lines and their surrounding layers. While the thermal expansion effect is independent of aluminum line dimensions, the passivation deformation effect dominates preferentially in wide aluminum lines. Bulge deformation of the passivation layer is caused by its own compressive stress, forcing the encapsulated aluminum to expand. In fine lines, void formation is controlled by the volume difference caused by the thermal expansion mismatch and aluminum diffusion     

Palladium‐Catalyzed Three‐Component Reaction of 3‐(Tri‐n‐ butylstannyl)allyl Acetates,Aldehydes, and Triorganoboranes: An Alternative to the Carbonyl Allylation Using α,γ‐Substituted Allylic Tin Reagents

A three‐component reaction of 3‐(tri‐n‐butylstannyl)allyl acetates, aldehydes, and triorganoboranes in the presence of a palladium‐Xantphos catalyst system predominately gave (E)‐anti‐homoallylic alcohols with high diastereoselectivity and good to high levels of alkene stereocontrol. An efficient chirality transfer was observed when an enantioenriched substrate was employed. The reaction was initiated by the formation of an allylic gem‐palladium/stannyl intermediate, which subsequently underwent allylation of the aldehyde by an allyltributyltin followed by a coupling reaction of the in‐situ‐generated (E)‐vinylpalladium acetate with the triorganoborane.