JST ERATO

Kawasaki, Japan

JST ERATO

Kawasaki, Japan

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Kazi R.H.,JST ERATO | Kazi R.H.,National University of Singapore | Igarashi T.,JST ERATO | Igarashi T.,University of Tokyo | And 2 more authors.
Conference on Human Factors in Computing Systems - Proceedings | Year: 2012

Vignette is an interactive system that facilitates texture creation in pen-and-ink illustrations. Unlike existing systems, Vignette preserves illustrators' workflow and style: users draw a fraction of a texture and use gestures to automatically fill regions with the texture. We currently support both 1D and 2D synthesis with stitching. Our system also has interactive refinement and editing capabilities to provide a higher level texture control, which helps artists achieve their desired vision. A user study with professional artists shows that Vignette makes the process of illustration more enjoyable and that first time users can create rich textures from scratch within minutes. Copyright 2011 ACM.


Choi M.G.,University of Edinburgh | Yang K.,Seoul National University | Igarashi T.,JST ERATO | Igarashi T.,University of Tokyo | And 3 more authors.
Computer Graphics Forum | Year: 2012

We propose 2D stick figures as a unified medium for visualizing and searching for human motion data. The stick figures can express a wide range or human motion, and they are easy to be drawn by people without any professional training. In our interface, the user can browse overall motion by viewing the stick figure images generated from the database and retrieve them directly by using sketched stick figures as an input query. We started with a preliminary survey to observe how people draw stick figures. Based on the rules observed from the user study, we developed an algorithm converting motion data to a sequence of stick figures. The feature-based comparison method between the stick figures provides an interactive and progressive search for the users. They assist the user's sketching by showing the current retrieval result at each stroke. We demonstrate the utility of the system with a user study, in which the participants retrieved example motion segments from the database with 102 motion files by using our interface. © 2012 The Author(s).


Iwasa T.,JST ERATO | Nakajima A.,Keio University
Chemical Physics Letters | Year: 2013

We present the physicochemical properties for the lowest-energy isomer of a boron-doped aluminum cluster of B2Al21-. The isomer was obtained by basin-hopping minimization based on the density functional theory, starting from a face-sharing bi-icosahedral structure in which two boron atoms were endohedrally doped to each icosahedron. The lowest-energy isomer is a triangular form in which an aluminum cage encapsulates two boron atoms endohedrally. The electronic structure was analyzed by projecting Kohn-Sham orbitals onto the spherical harmonics; occupied and unoccupied frontier orbitals are dominantly G- and H-symmetries, respectively. Optical absorption is mainly assigned to G to H transitions. © 2013 Elsevier B.V. All rights reserved.


Young J.E.,University of Manitoba | Ishii K.,JST ERATO | Ishii K.,University of Tokyo | Igarashi T.,JST ERATO | And 2 more authors.
International Conference on Intelligent User Interfaces, Proceedings IUI | Year: 2012

The style in which a robot moves, expressed through its gait or locomotion, can convey effective messages to peo-ple. For example, a robot could move aggressively in reac-tion to a person's actions, or alternatively react using a set of careful, submissive movements. Designing, implement-ing and programming robotic interfaces that react to users' actions with properly styled movements can be a difficult, daunting, and time consuming technical task. On the other hand, most people can easily perform such stylistic tasks and movements, for example, through acting them out. Following this observation, we propose to enable people to use their existing teaching skills to directly demonstrate to robots, via in-situ acting, a desired style of interaction. In this paper we present an initial style-by-demonstration (SBD) proof-of-concept of our approach, allowing people to teach a robot specific, interactive locomotion styles by providing a demonstration. We present a broomstick-robot interface for directly demonstrating locomotion style to a collocated robot, and a design critique evaluation by expe-rienced programmers that compares our SBD approach to traditional programming methods. Copyright © 2012 ACM.


Allen J.,JST ERATO | Young J.E.,University of Manitoba | Sakamoto D.,JST ERATO | Sakamoto D.,University of Tokyo | And 2 more authors.
Proceedings of the Designing Interactive Systems Conference, DIS '12 | Year: 2012

As robots continue to enter people's everyday spaces, we argue that it will be increasingly important to consider the robots' movement style as an integral component of their interaction design. That is, aspects of the robot's movement which are not directly related to a task at hand (e.g., pick up a ball) can have a strong impact on how people perceive that action (e.g., aggressively or hesitantly). We call these elements the movement style. We believe that perceptions of this kind of style will be highly dependent on the culture, group, or individual, and so people will need to have the ability to customize their robot. Therefore, in this work we use Style by Demonstration, a style focus on the more-traditional programming by demonstration technique, and present the Puppet Dancer system, an interface for constructing paired and interactive robotic dances. In this paper we detail the Puppet Dancer interface and interaction design, explain our new algorithms for teaching dance by demonstration, and present the results from a formal qualitative study. © 2012 ACM.


Takahashi H.,Kyoto University | Tahara Y.,JST ERATO | Sawada S.-I.,Kyoto University | Akiyoshi K.,Kyoto University
Biomaterials Science | Year: 2013

A new intracellular protein delivery nanocarrier with protein stabilizing ability was constructed of cationic amphiphilic polysaccharide nanoballs. Amphiphilic enzymatically synthesized glycogen (ESG) made by modification of hydrophobic cholesterol groups to ESG, which is a monodispersed spherical hyper-branched polysaccharide nanoparticle, formed self-assembled cluster nanogels (CHESG nanogels) in water. Cationic amphiphilic ESG derivatives where the diethylethylenediamine (DEAE) group was introduced into CHESG (CHESG-DEAE) were positively charged, monodispersed, and non-aggregated amphiphilic nanoballs with hydrophobic nanodomains provided by the cholesterol groups. The CHESG-DEAE strongly interacted with proteins and stabilized them against thermal denaturation. Furthermore, the cationic CHESG effectively internalized a number of proteins into HeLa cells. This cationic ESG nanoball-based material shows great potential as an effective protein delivery nanocarrier. © 2013 The Royal Society of Chemistry.


Iwasa T.,JST ERATO | Iwasa T.,Keio University | Nakajima A.,JST ERATO | Nakajima A.,Keio University
Journal of Physical Chemistry C | Year: 2012

The geometric, electronic, and optical properties of a heterodimer and trimer consisting of metal-encapsulating silicon cage clusters, M@Si 16 (M = Sc, Ti, V) with D 4d symmetry, are studied using density functional computations to explore the possibility of using these clusters as building blocks for a nanometer scale heteroassembly. In this study, among the possible low-lying geometries, the linear-form of the hetero-oligomers is adopted as a model system, where the D 4d monomers are covalently bonded by facing their squares in an eclipsed fashion. The heterodimer consisting of halogen-like Sc@Si 16 and alkaline-like V@Si 16 has a dipole moment of 7.63 D, and its occupied and virtual frontier orbitals are localized to V@Si 16 and to Sc@Si 16, respectively. Some of the inner molecular orbitals exhibit superatomic bonding and antibonding character. The electronic excitations involve charge-transfer states mainly from V@Si 16 to Sc@Si 16 in the optical energy region. The linear heterotrimer of Sc@Si 16-Ti@Si 16- V@Si 16, formed by inserting the rare-gas-like Ti@Si 16, has a larger dipole moment of 15.6 D and one or more localized frontier orbitals compared to the dimer. We propose possible formation routes to realize the present hetero-oligomers using photoexcitation or energy-selective electron injection into several LUMOs of the monomers that are suitable for linear-oligomerization. © 2012 American Chemical Society.


Iwasa T.,JST ERATO | Iwasa T.,Keio University | Nobusada K.,Japan Institute for Molecular Science | Nakajima A.,JST ERATO | Nakajima A.,Keio University
Journal of Physical Chemistry C | Year: 2013

Electronic and optical properties of vertex sharing homo- and heterobiicosahedral gold clusters [M1M2Au 23(PH3)10(SCH3)5Cl 2]2+ (M1/M2 = Au/Au, Pt/Hg) are investigated by means of density functional computations, focusing on superatom assembly. In the homo clusters, the projected density of states onto the spherical harmonics reveals that each icosahedral unit behaves as a superatom with the Au(6s6p) electrons and electron shell closings of S and P orbitals followed by unoccupied D orbitals; each unit satisfies an 8-electron superatom condition. Because the Au(5d) band appears between the S and P orbitals, the electronic structure is characterized as S, Au(5d)-band, and P. The lowest electronic excitation in the homo cluster is the P to D transition. In the hetero biicosahedral cluster, the central Au atoms of each icosahedron are replaced by Pt and Hg. The HOMO and LUMO are well localized to the PtAu 12 and HgAu12 units, respectively, forming a cluster-assembled heterojunction in a single stable structure. The absorption spectrum of the heterobiicosahedral cluster is characterized by charge transfer from PtAu12 to HgAu12 in the visible region, accompanied by a weak charge transfer in the opposite direction. Despite low numbers of charge carriers, the heterobiicosahedral cluster shows a large dipole moment. © 2013 American Chemical Society.


Goretta S.A.,Osaka University | Kinoshita M.,JST ERATO | Mori S.,Osaka University | Tsuchikawa H.,Osaka University | And 2 more authors.
Bioorganic and Medicinal Chemistry | Year: 2012

Sphingomyelin (SM) and cholesterol form microdomains called lipid rafts in cellular membranes. To develop a versatile fluorescent lipid probe, chemical modifications to both the hydrophobic and hydrophilic portions of SM are essential. Few reports describing SM probes with a fluorophore at the polar head group have been published. This study examined the effect of substitution on an ammonium moiety of SM on the membrane properties of SM. Two SM analogs with small propargyl and allyl groups on the quaternary nitrogen atom were synthesized and subjected to analysis using differential scanning calorimetry, fluorescent anisotropy, detergent solubilization, surface pressure, and density measurements. Results demonstrated that the two SM analogs retained the membrane properties of SM, including formation of an ordered phase and the ability to interact with cholesterol. A dansyl-substituted SM was prepared for fluorescent measurements. Dansyl-SM showed less of a propensity to form microdomains. These findings imply the potential application of N-substituted SMs as a raft-specific molecular probe. © 2012 Elsevier Ltd. All rights reserved.


PubMed | Osaka University, JST ERATO, Kyoto University, University of Tokyo and RIKEN
Type: Journal Article | Journal: Biochimica et biophysica acta | Year: 2016

Theonellamides (TNMs) are antifungal and cytotoxic bicyclic dodecapeptides derived from the marine sponge Theonella sp. These peptides specifically bind to 3-hydroxysterols, resulting in 1,3--D-glucan overproduction and membrane damage in yeasts. The inclusion of cholesterol or ergosterol in phosphatidylcholine membranes significantly enhanced the membrane affinity of theonellamide A (TNM-A) because of its direct interaction with 3-hydroxyl groups of sterols. To better understand TNM-induced membrane alterations, we investigated the effects of TNM-A on liposome morphology. (31)P nuclear magnetic resonance (NMR) and dynamic light scattering (DLS) measurements revealed that the premixing of TNM-A with lipids induced smaller vesicle formation. When giant unilamellar vesicles were incubated with exogenously added TNM-A, confocal micrographs showed dynamic changes in membrane morphology, which were more frequently observed in cholesterol-containing than sterol-free liposomes. In conjunction with our previous data, these results suggest that the membrane action of TNM-A proceeds in two steps: 1) TNM-A binds to the membrane surface through direct interaction with sterols and 2) accumulated TNM-A modifies the local membrane curvature in a concentration-dependent manner, resulting in dramatic membrane morphological changes and membrane disruption.

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