Variance based time-frequency mask estimation for unsupervised speech enhancement

Multimedia Tools and Applications - Variance based two dimensional time-frequency mask estimation for unsupervised speech enhancement is proposed to improve the speech quality and intelligibility...     

Palynological characteristics of some selected species of family Cucurbitaceae (Juss.) using light and scanning electron microscopy techniques

The pollen morphology of 11 species distributed in seven genera belonging to family Cucurbitaceae has been studied using light microscopy (LM) as well as scanning electron microscopy. Pollen morphology of this family is diverse and is almost europalynous. Nearly all types of pollen belonging to different size class and shape class with a variety of exine sculpturing are found in the family. Pollen grains are usually triporate to tricolporate, prolate, oblate‐spheroidal, spheroidal, to suboblate, radially symmetrical, and isopolar. The common exine pattern is reticulate of various forms ranging from finely reticulate to coarsely reticulate with some species having echinate type of exine ornamentation, for example, Cucurbita pepo and Praecitrullus fistulosus. Most of the studied species are somewhat triangular with respect to equatorial outlook and circular to elliptic in polar outlook. The palynological characteristics of the members of the family are useful in identification of taxa at generic level mostly. Based on the present study it is not recommended to wholly solely depend upon the pollen morphology for the identification of taxa especially at specific levels because very minor differences regarding pollen characters exist among the species of the same genera.     

Effect of gamma irradiation on the extraction yield, total phenolic content and free radical-scavenging activity of Nigella staiva seed

In the present study, the radiation processing of Nigella sativa seed samples was carried out at dose levels of 2, 4, 8, 10, 12 and 16 kGy. The extraction yield, total phenolic content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity of both control and irradiated samples extracted in acetone, methanol and water were assessed. The results showed that the extraction yields increased with an increase in radiation dose for all the test solvents. At 16 kGy the increases were 3.7%, 4.2%, 5.6% and 9.0% for hexane, acetone, water and methanol extracts, respectively. The phenolic content in the acetone extract was found to be increased from 3.7 for the control sample to 3.8 mg/g for the 16 kGy radiation-processed sample. No significant change was observed for the phenolic content of the methanolic extract, while the aqueous extract showed a decrease at dose levels of 12 and 16 kGy. In the control samples, the DPPH radical-scavenging activity was 79.4%, 79.1% and 92.0% for water, acetone and methanol extracts, respectively, at 5 mg/ml concentration. Gamma irradiation enhanced the scavenging activity in acetone and methanol extracts by 10.6% and 5.4%, respectively, at 16 kGy. In summary, gamma irradiation increased the extraction yield and total phenolic content, as well as enhancing the free radical-scavenging activity. In addition, the type of solvent used for extraction also affected the impact of irradiation on antioxidant activity and total phenolic content of N. sativa seed.     

Impact of germination time and type of illumination on carotenoidcontent,protein solubility and in vitro protein digestibility of chickpea(Cicer arietinum L.) sprouts

Sprouts have been reported to be nutritionally superior to their respective seeds with higher levels of nutrients and lower amounts of antinutrients. Significant differences occur in these nutrients and antinutrients with germination under different types of illumination. This paper reports the impact of germination conditions on changes in β-carotene content, protein solubility and in vitro protein digestibility of chickpea sprouts. The influence of germination time, type of illumination and their interaction on β-carotene content, protein solubility and in vitro protein digestibility of chickpea sprouts was highly significant (p < 0.01). Highest value for β-carotene were observed for sprouts germinated under yellow light for 72 h (131.74 mg 100 g⁻¹) and lowest for blue light group after 120 h germination. Sprouts of irradiated group had overall higher content of β-carotene throughout germination period. Protein solubility was also higher for sprouts of irradiated group and green illumination group after 120 h germination. Sprouts of irradiated group had highest value for% in vitro protein digestibility after 96 h germination followed by the same group after 120 h germination. It is inferred from the study that irradiation of chickpea seed prior to germination improved the β-carotene content, protein solubility and in vitro protein digestibility of chickpea sprouts.     

Effect of Irradiation on Microbial Safety and Nutritional Quality of Minimally Processed Bitter Gourd (Momordica charantia)

ABSTRACT: The feasibility of gamma radiation in combination with low temperature was studied to ensure microbiological safety and maintaining physicochemical and sensory characteristics of minimally processed bitter gourd. Radio sensitivity (D₁₀ values, that is, irradiation dose required for 90% reduction of microorganisms) for Salmonella paratyphae A and Escherichia coli were 0.28 kGy and 0.23 kGy, respectively. On the basis of D₁₀ values, 5D₁₀ values were determined and samples of minimally processed bitter gourd were irradiated up to 5D₁₀ values, stored for 14 d at 5 ± 1 °C, and analyzed for total bacterial, fungal, and coliform counts. Ascorbic acid, acidity, texture, and sensory qualities were also studied. Results showed that an irradiation dose of 2.0 kGy significantly reduced the microbial count to keep the samples microbiologically safe for 7d. Sensory evaluation revealed that the samples received maximum scores for appearance and flavor (7.8 and 7.9, respectively) with radiation dose of 2.0 kGy and minimum score for control (6.5). Firmness and ascorbic acid content decreased significantly with increase in storage time and irradiation dose. All the samples were discarded during the 2nd wk of storage due to high bio-burden.     

Does urban form matter in solo and joint activity engagement?

This research examines how the residential built environment relates to residents’ solo versus joint engagement in shopping, dining, and recreational/fitness activities. Using data from the 2006 Greater Triangle Travel Survey in North Carolina, individual activity engagement is innovatively measured using two indicators: total time spent alone and total time jointly spent with household members on a specific non-work activity type. The impact of the built environment on non-work activity engagement is then estimated using Heckman sample selection models along with a seemingly unrelated estimation system. We find that residents living closer to parks and department stores on average are more likely to participate in out-of-home recreation and shopping activities. A comparison of coefficients in solo versus joint engagement models shows that park accessibility is much more important to household joint participation than to solo participation in recreational activities. The research generates new knowledge on how the built environment may influence solo versus joint activity engagement differently. The findings are useful to urban planners who are interested in reviving local economy and promoting active living/social interaction.     

Keyframe‐based thermal–inertial odometry

Autonomous navigation of microaerial vehicles in environments that are simultaneously GPS‐denied and visually degraded, and especially in the dark, texture‐less and dust‐ or smoke‐filled settings, is rendered particularly hard. However, a potential solution arises if such aerial robots are equipped with long wave infrared thermal vision systems that are unaffected by darkness and can penetrate many types of obscurants. In response to this fact, this study proposes a keyframe‐based thermal–inertial odometry estimation framework tailored to the exact data and concepts of operation of thermal cameras. The front‐end component of the proposed solution utilizes full radiometric data to establish reliable correspondences between thermal images, as opposed to operating on rescaled data as previous efforts have presented. In parallel, taking advantage of a keyframe‐based optimization back‐end the proposed method is suitable for handling periods of data interruption which are commonly present in thermal cameras, while it also ensures the joint optimization of reprojection errors of 3D landmarks and inertial measurement errors. The developed framework was verified with respect to its resilience, performance, and ability to enable autonomous navigation in an extensive set of experimental studies including multiple field deployments in severely degraded, dark, and obscurants‐filled underground mines.