High-count Multi-Core Fibers for Space-Division Multiplexing with Propagation-Direction Interleaving

By introducing a square lattice structure for bidirectional core assignments in multi-core fibers, the e ectiveness of propagation-direction interleaving for crosstalk reduction can be increased, realizing a 24-core fiber with-30.6 dB crosstalk over 100 km

Geometrical and band-structure effects on phonon-limited hole mobility in rectangular cross-sectional germanium nanowires

We calculated the phonon-limited hole mobility in rectangular cross-sectional [001], [110], [111], and [112]-oriented germanium nanowires, and the hole transport characteristics were investigated. A tight-binding approximation was used for holes, and phonons were described by a valence force field model. Then, scattering probability of holes by phonons was calculated taking account of hole-phonon interaction atomistically, and the linearized Boltzmann's transport equation was solved to calculate the hole mobility at low longitudinal field. The dependence of the hole mobility on nanowire geometry was analyzed in terms of the valence band structure of germanium nanowires, and it was found that the dependence was qualitatively reproduced by considering an average effective mass and the density of states of holes. The calculation revealed that [110] germanium nanowires with large height along the [001] direction show high hole mobility. Germanium nanowires with this geometry are also expected to exhibit high electron mobility in our previous work, and thus they are promising for complementary metal-oxide-semiconductor (CMOS) applications

Multiferroic FeTe2_2O5_5Br: Alternating spin chains with frustrated interchain interactions

A combination of density functional theory calculations, many-body model considerations, magnetization and electron spin resonance measurements shows that the multiferroic FeTe$_2$O$_5$Br should be described as a system of alternating antiferromagnetic $S=5/2$ chains with strong Fe-O-Te-O-Fe bridges weakly coupled by two-dimensional frustrated interactions, rather than the previously reported tetramer models. The peculiar temperature dependence of the incommensurate magnetic vector can be explained in terms of interchain exchange striction being responsible for the emergent net electric polarization.Comment: 7 pages, 6 figure

New Perspectives in Sinographic Language Processing Through the Use of Character Structure

Chinese characters have a complex and hierarchical graphical structure carrying both semantic and phonetic information. We use this structure to enhance the text model and obtain better results in standard NLP operations. First of all, to tackle the problem of graphical variation we define allographic classes of characters. Next, the relation of inclusion of a subcharacter in a characters, provides us with a directed graph of allographic classes. We provide this graph with two weights: semanticity (semantic relation between subcharacter and character) and phoneticity (phonetic relation) and calculate "most semantic subcharacter paths" for each character. Finally, adding the information contained in these paths to unigrams we claim to increase the efficiency of text mining methods. We evaluate our method on a text classification task on two corpora (Chinese and Japanese) of a total of 18 million characters and get an improvement of 3% on an already high baseline of 89.6% precision, obtained by a linear SVM classifier. Other possible applications and perspectives of the system are discussed.Comment: 17 pages, 5 figures, presented at CICLing 201

Correlated oscillations in Kerr parametric oscillators with tunable effective coupling

We study simultaneous parametric oscillations in a system composed of two distributed-element-circuit Josephson parametric oscillators in the single-photon Kerr regime coupled via a static capacitance. The energy of the system is described by a two-bit Ising Hamiltonian with an effective coupling whose amplitude and sign depend on the relative phase between parametric pumps. We demonstrate that the binary phases of the parametric oscillations are correlated with each other, and that the parity and strength of the correlation can be controlled by adjusting the pump phase. The observed correlation is reproduced in our simulation taking pure dephasing into account. The present result demonstrates the tunability of the Hamiltonian parameters by the phase of external microwave, which can be used in the the Ising machine hardware composed of the KPO network.Comment: 9 pages, 8 figure

LHR band emissions at mid-latitude and their relationship to ionospheric ELF hiss and relativistic electrons

LHR band emissions observed at mid-latitude were investigated using data from the EXOS-C (Ohzora) satellite. A typical feature of the LHR band emissions is a continuous banded structure without burst-like and cut-off features whose center frequency decreases as the satellite moves to higher latitudes. A statistical analysis of the occurrence characteristics of the phenomena showed that mid-latitude LHR emissions are distributed inside the plasmapause during magnetically quiet periods, and the poleward boundary of the emission region moves to lower latitudes as the magnetic activity increases. The altitude distribution of the waves suggests that the propagation in the LHR duct formed horizontally in the mid-latitude upper-ionosphere. The emission is closely related to the occurrence of ionospheric ELF hiss. It is also shown that LHR emissions are commonly observed in the slot region of the radiation belt, and they sometimes accompany the enhancement of the ionospheric electron temperature. The generation of the LHR band emissions is discussed based on the observed characteristics

Equal Intensity Contours for Whole-Body Vibrations Compared with Vibrations Cross-Modally Matched to Isophones

Abstract. In this study, two experiments were conducted to determine the curves of equal intensity perception for sinusoidal vertical whole-body vibrations (WBV) of seated subjects over the frequency range from 10Hz to 250Hz. Vibrations were presented to subjects using a at hard seat. In total, 10 participants were asked to match the intensity of dierent vibrations, using a method of adjustment. The obtained contours were compared with the threshold of vibration and to vibrations cross-modally matched to tones from isophones. The shapes of the equal intensity contours in the present study show reasonable agreement with the contours from other studies despite the use of dierent methodologies and experimental questions. The contours show a characteristic similar to the perception threshold. No dependency of vibration magnitude on the shape of the contours was found in the applied dynamic range. However, large inter-individual variations were observed. The results imply that vibration curves that are cross-modally matched to isophones show similar characteristics

Experimental Demonstration of 6-Mode Division Multiplexed NG-PON2: Cost Effective 40 Gbit/s/Spatial-Mode Access Based on 3D Laser Inscribed Photonic Lanterns

We report the first space-division-multiplexed based symmetric NG-PON2 network by efficiently transmitting 40 Gbit/s/spatial-mode. Error free transmission (BER of 10-9) is obtained for all the downstream and upstream data tributaries over 1-km 6-spatial-mode FMF without using MIMO DSP

12-core x 3-mode Dense Space Division Multiplexed Transmission over 40 km Employing Multi-carrier Signals with Parallel MIMO Equalization

We demonstrate dense SDM transmission of 20-WDM multi-carrier PDM-32QAM signals over a 40-km 12-core x 3-mode fiber with 247.9-b/s/Hz spectral efficiency. Parallel MIMO equalization enables 21-ns DMD compensation with 61 TDE taps per subcarrier