Voice Conversion Based on Cross-Domain Features Using Variational Auto Encoders

An effective approach to non-parallel voice conversion (VC) is to utilize deep neural networks (DNNs), specifically variational auto encoders (VAEs), to model the latent structure of speech in an unsupervised manner. A previous study has confirmed the ef- fectiveness of VAE using the STRAIGHT spectra for VC. How- ever, VAE using other types of spectral features such as mel- cepstral coefficients (MCCs), which are related to human per- ception and have been widely used in VC, have not been prop- erly investigated. Instead of using one specific type of spectral feature, it is expected that VAE may benefit from using multi- ple types of spectral features simultaneously, thereby improving the capability of VAE for VC. To this end, we propose a novel VAE framework (called cross-domain VAE, CDVAE) for VC. Specifically, the proposed framework utilizes both STRAIGHT spectra and MCCs by explicitly regularizing multiple objectives in order to constrain the behavior of the learned encoder and de- coder. Experimental results demonstrate that the proposed CD- VAE framework outperforms the conventional VAE framework in terms of subjective tests.Comment: Accepted to ISCSLP 201

Double grating formation in anisotropic photorefractive crystals

Double gratings form in anisotropic photorefractive crystals when two plane waves intersecting inside the crystal have both extraordinary and ordinary wave components. The effect can be observed by reading out the two gratings with extraordinary or ordinary light. Experiments confirm the theoretical predictions. The relevance of these results in using photorefractive crystals for holographic storage is discussed

GRB beaming and gravitational-wave observations

Using the observed rate of short-duration gamma-ray bursts (GRBs) it is possible to make predictions for the detectable rate of compact binary coalescences in gravitational-wave detectors. These estimates rely crucially on the growing consensus that short gamma-ray bursts are associated with the merger of two neutron stars or a neutron star and a black hole, but otherwise make no assumptions beyond the observed rate of short GRBs. In particular, our results do not assume coincident gravitational wave and electromagnetic observations. We show that the non-detection of mergers in the existing LIGO/Virgo data constrains the progenitor masses and beaming angles of gamma-ray bursts. For future detectors, we find that the first detection of a NS-NS binary coalescence associated with the progenitors of short GRBs is likely to happen within the first 16 months of observation, even in the case of a modest network of observatories (e.g., only LIGO-Hanford and LIGO-Livingston) operating at modest sensitivities (e.g., advanced LIGO design sensitivity, but without signal recycling mirrors), and assuming a conservative distribution of beaming angles (e.g. all GRBs beamed at \theta=30 deg). Less conservative assumptions reduce the waiting time until first detection to weeks to months. Alternatively, the compact binary coalescence model of short GRBs can be ruled out if a binary is not seen within the first two years of operation of a LIGO-Hanford, LIGO-Livingston, and Virgo network at advanced design sensitivity. We also demonstrate that the rate of GRB triggered sources is less than the rate of untriggered events if \theta<30 deg, independent of the noise curve, network configuration, and observed GRB rate. Thus the first detection in GWs of a binary GRB progenitor is unlikely to be associated with a GRB

Alignment sensitivity of holographic three-dimensional disks

We describe the rotational alignment sensitivity of three-dimensional holographic disks. It is shown that the reconstructed image always rotates by the angle by which the disk rotates; however, the center and the radius of rotation change as the recording geometry changes. A comparison among image plane, Fourier plane, and Fresnel holograms is given, and an optimum configuration (in terms of alignment sensitivity) in which the radius of rotation is zero is derived. We present experimental results and also discuss how the rotation alignment sensitivity affects the storage density and the readout–recording speed of the three-dimensional disk. A brief summary of other sources of misalignment is given

Air mixing criteria for ceiling slot-ventilated agricultural enclosures

The use of a scale-model is an effective technique to predict the performance of ventilation in full-scale prototypes. Many criteria have been proposed to simulate the behavior of airflow between scale-model and prototype. Because of the inconsistent results of past proposed similarity criteria, more validation work is needed to clarify the conflicts;Dimensional analysis using both the Buckingham Pi method and manipulating the governing differential equations was used to theoretically establish similarity parameters. Only partial similarity was reached since conflicts exist between proposed similarity parameters;Experiments of two scale models were conducted to study airflow similarity in ceiling slot-ventilated agricultural enclosures using different similarity criteria. The evaluation of similarity between scale-model and prototype included validation of penetration distance, airflow pattern, airspeed field, and temperature field using methods that included smoke visualization, airspeed field measurement, and temperature field measurement;The studies focused on the Reynolds number (Re) and inlet jet momentum ratio (Rm) as the similitude criteria for isothermal airflow, and Archimedes number (Ar) for nonisothermal airflow. The experimental results offer better agreement using Rm than using Re as the similitude criterion for isothermal airflow. Ar is an appropriate similitude criterion when the nonisothermal airflow pattern exhibits two-circulation airflow behavior. After the airflow is increased resulting in a single-circulation airflow, Rm associated with a similar heat load becomes the better similitude criteria;Future studies including improvement of the evaluation method, more complete investigation of the enclosure, variation of scale dimension and configuration layout, and better control of the experimental environment are recommended

Three-dimensional holographic disks

We describe optical disks that store data holographically in three dimensions by using either angle multiplexing or wavelength multiplexing. Data are stored and retrieved in parallel blocks or pages, and each page consists of approximately 106 bits. The storage capacity of such disks is derived as a function of disk thickness, pixel size, page size, and scanning parameters. The optimum storage density is approximately 120 bits/µm^2

Do Degradation of Urban Greenery and Increasing Land Prices Often Come along with Urbanization?

In the wake of urbanization, driven by a variety of individual and socio-economic merits, human’s basic residential needs and standard of living may be compromised in the urban areas, as the population agglomerates. However, the knowledge of the associations of urbanization with urban greenery and residential land prices is still in the pursuing process. This empirical research aims to contribute whether the degradation of essential living conditions is a trade-off for the pursued urban life. Hence, Taiwan is selected as the case to analyze the associated relations primarily between 1976 and 2016. The research methods involve descriptive statistics, the panel data analysis, and the cluster analysis. The panel data analysis demonstrates that degraded urban greenery and increasing residential land prices came along with the urbanization in Taiwan between 2001 and 2016. Policy implications include rethinking of the building coverage rate for renewed buildings for more plant-friendly ground, the adoption of building setback policy for more accessible mid-air mini-parks, and avoiding residential units as an investment commodity

Viewing angle of binary neutron star mergers

The joint detection of the gravitational wave (GW) GW170817 and its electromagnetic (EM) counterparts GRB170817A and kilonova AT 2017gfo has triggered extensive study of the EM emission of binary neutron star mergers. A parameter which is common to and plays a key role in both the GW and the EM analyses is the viewing angle of the binary's orbit. If a binary is viewed from different angles, the amount of GW energy changes (implying that orientation and distance are correlated) and the EM signatures can vary, depending on the structure of the emission. Information about the viewing angle of the binary orbital plane is therefore crucial to the interpretation of both the GW and the EM data, and can potentially be extracted from either side. In the first part of this study, we present a systematic analysis of how well the viewing angle of binary neutron stars can be measured from the GW data. We show that if the sky position and the redshift of the binary can be identified via the EM counterpart and an associated host galaxy, then for 50$\%$ of the systems the viewing angle can be constrained to $\leq 7^{\circ}$ uncertainty from the GW data, independent of electromagnetic emission models. On the other hand, if no redshift measurement is available, the measurement of the viewing angle with GW alone is not informative, unless the true viewing angle is close to $90^{\circ}$. This holds true even if the sky position is measured independently. Then, we consider the case where some constraints on the viewing angle can be placed from the EM data itself. We show that the EM measurements can then be used in the analysis of GW data to improve the precision of the luminosity distance, and hence of the Hubble constant, by a factor of 2 to 3.Comment: Accepted by Physical Review

A Culturally Aware Approach to Learning System Interface Design

This mixed methods research explored interface design strategies for users from different cultures and localized settings. Guided by the cultural-historical development theory and HCI research, four critical factors—navigation design, information organization, layout design, and visuals—were investigated in designing culturally relevant interfaces for Americans and Taiwanese. American and Taiwanese groups—both contained two sub-groups of 30 participants—were recruited for the quantitative phase. Each participant was exposed to only one interface with content composed in their native language. However, one sub-group in each ethnic group was exposed to a culturally relevant interface and another was exposed to an alien interface. MANOVA on overall performance in both American and Taiwanese groups were significant. Americans performed better using the American interface (Wilks’s Λ=.85, F= 5.15, p< .01). They had significantly shorter performance time in the American (M=775) than the Taiwanese (M=1003) interface (F=6.29, p<.05), but differences on performance accuracy were not significant (F=2.74, p=.103). Taiwanese performed better using the Taiwanese interface (Wilks’s Λ=.67, F=14.06, p< .01). They had shorter performance time in the Taiwanese (M=743) than the American (M=1353) interface (F=6.29, p<.05), and they also had higher performance accuracy on the Taiwanese (M=11.7) than the American (M=10.0) interface (F=7.94, p<.01). In addition, t-test on overall preference in both American and Taiwanese groups were significant. Americans preferred the American (M=58.5) over the Taiwanese (M=53.0) interface (t=2.11, p< .05). And Taiwanese preferred the Taiwanese (M=58.7) over the American (M=46.9) interface (t=3.48, p<.01). Qualitative interviews of six American and six Taiwanese participants revealed three themes: First, when searching, Taiwanese were explorative and relied on hierarchical relationships; while Americans relied on prior experiences and analytical categorizations. Second, both groups have higher affiliation with design features matching their preferences. Finally, matching design features with users’ expectations and needs promotes positive perceptions and enhances interface usability. Both quantitative and qualitative Results imply that user interface designers should consider cultural perspectives when designing interfaces for online learning systems. Further studies might consider the relative impacts of the navigation, information structure, layout, and visual design on a broad range of user differences might have on learning