Learning Deep Input-Output Stable Dynamics

Learning stable dynamics from observed time-series data is an essential problem in robotics, physical modeling, and systems biology. Many of these dynamics are represented as an inputs-output system to communicate with the external environment. In this study, we focus on input-output stable systems, exhibiting robustness against unexpected stimuli and noise. We propose a method to learn nonlinear systems guaranteeing the input-output stability. Our proposed method utilizes the differentiable projection onto the space satisfying the Hamilton-Jacobi inequality to realize the input-output stability. The problem of finding this projection can be formulated as a quadratic constraint quadratic programming problem, and we derive the particular solution analytically. Also, we apply our method to a toy bistable model and the task of training a benchmark generated from a glucose-insulin simulator. The results show that the nonlinear system with neural networks by our method achieves the input-output stability, unlike naive neural networks. Our code is available at https://github.com/clinfo/DeepIOStability.Comment: Accepted in NeurIPS 202

Localized knowledge spillovers and patent citations: A distance-based approach

We develop a new approach to localized knowledge spillovers by incorporating the concept of control patents (Jaffe, Trajtenberg and Henderson 1993) into the distance-based test of localization (Duranton and Overman, 2005). Using microgeographic data, we identify localization distance while allowing for cross-boundary spillovers, unlike the existing literature where the extent of localized knowledge spillovers is detected at the state or metropolitan statistical area level. We revisit the recent debate by Thompson and Fox-Kean (2005) and Henderson, Jaffe and Trajtenberg (2005) on the existence of localized knowledge spillovers, and find solid evidence supporting localization, even when finer controls are used.

Random lasing in dye-doped polymer random media with a bubble structure

We experimentally investigate random laser (RL) emission from dye-doped polymer random media with inhomogeneously distributed scatterers. A random structure, which we call a bubble structure (BS), is realized by using nonscattering spacer particles randomly distributed in a gain medium. The experimental results show that the bubble-structured RL that incorporates an appropriate amount of spacer particles exhibits a higher spectral peak and a larger slope efficiency than conventional RLs. The highest peak intensity is observed when the size variation of spacer particles is maximized. Furthermore, an analysis of laser modes reveals that an increase in the spectral peak intensity can be partly attributed to the mode selection properties of the BS

(2-Hy­droxy-7-meth­oxy­naphthalen-1-yl)(phen­yl)methanone

In the mol­ecule of the title compound, C18H14O3, there is an intra­molecular O—H⋯O=C hydrogen bond between the carbonyl and hy­droxy groups on the naphthalene ring system. The angles between the C=O bond vector and the least-squares planes of the naphthalene ring system and the phenyl ring are 30.58 (6) and 42.82 (7)°, respectively, while the dihedral angle between the naphthalene ring system and the phenyl ring is 58.65 (5)°. In the crystal, mol­ecules are connected by pairs of inter­molecular O—H⋯O=C hydrogen bonds, forming centrosymmetric dimers

1-[(4-Chloro­phen­yl)(phenyl­imino)­meth­yl]-7-meth­oxy-2-naphthol–1,4-diaza­bicyclo­[2.2.2]octane (2/1)

In the crystal structure of the title cocrystal, 2C24H18ClNO2·C6H12N2, the 1,4-diaza­bicyclo­[2.2.2]octane mol­ecule is located on a twofold rotation axis and linked to the two triaryl­imine mol­ecules by O—H⋯N hydrogen bonds, forming a 2:1 aggregate. C—H⋯Cl inter­actions are also observed. In the triaryl­imine mol­ecule, the naphthalene ring system makes dihedral angles of 80.39 (6) and 82.35 (6)°, respectively, with the phenyl and benzene rings. The dihedral angle between these two latter rings is 87.09 (7)°

Electronic Properties of BaPtP with a Noncentrosymmetric Cubic Crystal Structure

We report the synthesis, electronic properties, and electronic structure of LaIrSi-type BaPtP with a noncentrosymmetric cubic crystal structure. Electrical resistivity and heat capacity data taken by using polycrystalline samples indicated that BaPtP is a metal, which was further supported by first principles calculations. A polycrystalline sample of BaPtP showed a zero resistivity below 0.2 K due to the superconducting transition. The first principles calculation results indicated that the spin splitting at around the Fermi energy is large in BaPtP. These results suggest that BaPtP is likely to exhibit interesting physical properties caused by a strong spin-orbit coupling of 5d electrons in the Pt atoms.Comment: 4 pages, 4 figures, JPS Conf. Proc., accepte

Onoma-to-wave: Environmental sound synthesis from onomatopoeic words

In this paper, we propose a framework for environmental sound synthesis from onomatopoeic words. As one way of expressing an environmental sound, we can use an onomatopoeic word, which is a character sequence for phonetically imitating a sound. An onomatopoeic word is effective for describing diverse sound features. Therefore, using onomatopoeic words for environmental sound synthesis will enable us to generate diverse environmental sounds. To generate diverse sounds, we propose a method based on a sequence-to-sequence framework for synthesizing environmental sounds from onomatopoeic words. We also propose a method of environmental sound synthesis using onomatopoeic words and sound event labels. The use of sound event labels in addition to onomatopoeic words enables us to capture each sound event's feature depending on the input sound event label. Our subjective experiments show that our proposed methods achieve higher diversity and naturalness than conventional methods using sound event labels