1,998 research outputs found
Statistical Beamformer Exploiting Non-stationarity and Sparsity with Spatially Constrained ICA for Robust Speech Recognition
In this paper, we present a statistical beamforming algorithm as a
pre-processing step for robust automatic speech recognition (ASR). By modeling
the target speech as a non-stationary Laplacian distribution, a mask-based
statistical beamforming algorithm is proposed to exploit both its output and
masked input variance for robust estimation of the beamformer. In addition, we
also present a method for steering vector estimation (SVE) based on a noise
power ratio obtained from the target and noise outputs in independent component
analysis (ICA). To update the beamformer in the same ICA framework, we derive
ICA with distortionless and null constraints on target speech, which yields
beamformed speech at the target output and noises at the other outputs,
respectively. The demixing weights for the target output result in a
statistical beamformer with the weighted spatial covariance matrix (wSCM) using
a weighting function characterized by a source model. To enhance the SVE, the
strict null constraints imposed by the Lagrange multiplier methods are relaxed
by generalized penalties with weight parameters, while the strict
distortionless constraints are maintained. Furthermore, we derive an online
algorithm based on an optimization technique of recursive least squares (RLS)
for practical applications. Experimental results on various environments using
CHiME-4 and LibriCSS datasets demonstrate the effectiveness of the presented
algorithm compared to conventional beamforming and blind source extraction
(BSE) based on ICA on both batch and online processing.Comment: Accepted by TASL
Fast Marching based Rendezvous Path Planning for a Team of Heterogeneous Vehicle
A formulation is developed for deterministically calculating the optimized
paths for a multi-agent system consisting of heterogeneous vehicles. The
essence of this formulation is the calculation of the shortest time for each
agent to reach every grid point from its known initial position. Such arrival
time map can be readily assessed using the Fast Marching Method (FMM), a
computational algorithm originally designed for solving boundary value problems
of the Eikonal equation. Leveraging the FMM method, we demonstrate that the
minimal time rendezvous point and paths for all member vehicles can be uniquely
determined with minimal computational concerns. To showcase the potential of
our method, we use an example of a virtual rendezvous scenario that entails the
coordination of a ship, an underwater vehicle, an aerial vehicle, and a ground
vehicle to converge at the optimal location within the Tampa Bay area in
minimal time. It illustrates the value of the developed framework in
efficiently constructing continuous path planning, while accommodating
different operational constraints of heterogeneous member vehicles
Corporate Social Responsibility Activities in Arts: Focusing on Performing Production Firms in South Korea
The purpose of this study was to investigate CSR activities in the field of arts and culture in South Korea. This study focused on government-driven CSR activities in performing arts production companies. The study collected 425 theater performance data samples from the 2015 Daehak-ro Culture Map Directory published by the Seoul Theater Center to examine which characteristics of performing arts production companies influence participation in the Nanum Ticket Program. Logistic regression analyses were performed with this data to test the hypotheses. After controlling several conditions, we found that the size of the production firm and the genre of the performance had significant effects on donation activities. In this study, the field of CSR empirical research in arts and cultural management was expanded by considering performing arts production companies as subjects of social contribution activities. This study also presents policy implications for expanding CSR activities in the field of arts and culture
Are Histrionic Personality Traits Associated with Irritability during Conscious Sedation Endoscopy?
Aim. We aimed to evaluate whether histrionic personality traits are associated with irritability during conscious sedation endoscopy (CSE). Materials and Methods. A prospective cross-sectional study was planned. Irritability during CSE was classified into five grades: 0, no response; I, minimal movement; II, moderate movement; III, severe movement; IV, fighting against procedure. Patients in grades III and IV were defined as the irritable group. Participants were required to complete questionnaire sheet assessing the extent of histrionic personality traits, extraversion-introversion, and current psychological status. The present authors also collected basic sociodemographic data including alcohol use history. Results. A total of 32 irritable patients and 32 stable patients were analyzed. The histrionic personality trait score of the irritable group was higher than that of the stable group (9.5 ± 3.1 versus 6.9 ± 2.9; P = 0.001), as was the anxiety score (52.8 ± 8.6 versus 46.1 ± 9.6; P = 0.004). Heavy alcohol use was more frequently observed in the irritable group (65.6% versus 28.1%; P = 0.003). In multivariate analysis, all these three factors were independently correlated with irritability during CSE. Conclusion. This study revealed that histrionic personality traits, anxiety, and heavy alcohol use can affect irritability during CSE
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Improved application of the electrophoretic tissue clearing technology, CLARITY, to intact solid organs including brain, pancreas, liver, kidney, lung, and intestine
Background: Mapping of tissue structure at the cellular, circuit, and organ-wide scale is important for understanding physiological and biological functions. A bio-electrochemical technique known as CLARITY used for three-dimensional anatomical and phenotypical mapping within transparent intact tissues has been recently developed. This method provided a major advance in understanding the structure-function relationships in circuits of the nervous system and organs by using whole-body clearing. Thus, in the present study, we aimed to improve the original CLARITY procedure and developed specific CLARITY protocols for various intact organs. Results: We determined the optimal conditions for reducing bubble formation, discoloration, and depositing of black particles on the surface of tissue, which allowed production of clearer organ images. We also determined the appropriate replacement cycles of clearing solution for each type of organ, and convincingly demonstrated that 250–280 mA is the ideal range of electrical current for tissue clearing. We then acquired each type of cleared organs including brain, pancreas, liver, lung, kidney, and intestine. Additionally, we determined the images of axon fibers of hippocampal region, the Purkinje layer of cerebellum, and vessels and cellular nuclei of pancreas. Conclusions: CLARITY is an innovative biochemical technology for the structural and molecular analysis of various types of tissue. We developed improved CLARITY methods for clearing of the brain, pancreas, lung, intestine, liver, and kidney, and identified the appropriate experimental conditions for clearing of each specific tissue type. These optimized methods will be useful for the application of CLARITY to various types of organs. Electronic supplementary material The online version of this article (doi:10.1186/s12861-014-0048-3) contains supplementary material, which is available to authorized users
Hypertensive brainstem encephalopathy involving deep supratentorial regions: does only blood pressure matter?
We report on a 42-year-old female patient who presented with high arterial blood pressure of 245/150 mmHg and hypertensive brainstem encephalopathy that involved the brainstem and extensive supratentorial deep gray and white matter. The lesions were nearly completely resolved several days after stabilization of the arterial blood pressure. Normal diffusion-weighted imaging findings and high apparent diffusion coefficient values suggested that the main pathomechanism was vasogenic edema owing to severe hypertension. On the basis of a literature review, the absolute value of blood pressure or whether the patient can control his/her blood pressure seems not to be associated with the degree of the lesions evident on magnetic resonance imaging. It remains to be determined if the acceleration rate and the duration of elevated arterial blood pressure might play a key role in the development of the hypertensive encephalopathy pattern
A Score-Based Evaluation Model for Rehabilitation of Existing Pumped Storage Hydropower Plant Construction
As the proportion of new and renewable energy increases, power control demands are becoming more frequent due to variability in power generation. As a complementary means against this, the pumped storage hydropower plants (PSHP) are attracting attention as energy storage systems (ESS), but it has high construction costs. Therefore, this study aims to improve the economic feasibility by developing the evaluation model of the existing infrastructure into an upper/lower dam suitable for PSHP. The concept of upper dam capacity is newly defined, and the evaluation index is constructed using normalization. A new evaluation system is presented for five factors: environment, stability, energy, capacity, and economy. Finally, it is tested in the pilot area in Korea. Several candidates, including the PSHP in operation, are found to have been distributed with higher scores. These results will help to satisfy the selection of candidates during the preliminary feasibility study phase, and programming them will enable more accurate and rapid assessment
Total Laparoscopic Hysterectomy and Laparoscopy-Assisted Vaginal Hysterectomy
This study suggests that total laparoscopic hysterectomy and laparoscopic-assisted vaginal hysterectomy are safe and feasible with laparoscopic-assisted hysterectomy preferred in patients with a mass involving the lower uterine segment or those with a large uterus
Characterization of the ATP transporter in the reconstituted rough endoplasmic reticulum proteoliposomes
AbstractAdenosine triphosphate (ATP) transporter from rat liver rough endoplasmic reticulum (RER) was solubilized and reconstituted into phosphatidylcholine liposomes. The RER proteoliposomes, resulting from optimizing some reconstitution parameters, had an apparent Km value of 1.5 μM and a Vmax of 286 pmol min−1 (mg protein)−1 and showed higher affinity for ATP and a lower Vmax value than intact RER (Km of 6.5 μM and Vmax of 1 nmol). ATP transport was time- and temperature-dependent, inhibited by 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid, which is known as an inhibitor of anion transporters including ATP transporter, but was not affected by atractyloside, a specific inhibitor of mitochondrial ADP/ATP carrier. The internal and external effects of various nucleotides on the ATP transport were examined. ATP transport was cis-inhibited strongly by ADP and weakly by AMP. ADP-preloaded RER proteoliposomes showed a specific increase of ATP transport activity while AMP-preloaded RER proteoliposomes did not show the enhanced overshoot peak in the ATP uptake plot. These results demonstrate the ADP/ATP antiport mechanism of ATP transport in rat liver RER
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