19 research outputs found
Visualizing Quaternion Multiplication
Quaternion rotation is a powerful tool for rotating vectors in 3-D; as a result, it has been used in various engineering fields, such as navigations, robotics, and computer graphics. However, understanding it geometrically remains challenging, because it requires visualizing 4-D spaces, which makes exploiting its physical meaning intractable. In this paper, we provide a new geometric interpretation of quaternion multiplication using a movable 3-D space model, which is useful for describing quaternion algebra in a visual way. By interpreting the axis for the scalar part of quaternion as a 1-D translation axis of 3-D vector space, we visualize quaternion multiplication and describe it as a combined effect of translation, scaling, and rotation of a 3-D vector space. We then present how quaternion rotation formulas and the derivative of quaternions can be formulated and described under the proposed approach.112sciescopu
Equivalent Circuit to Analyze the Transmitting Characteristics of a Cymbal Array
A cymbal transducer has a simple structure consisting of a piezoceramic disk and metallic caps and has broadband characteristics when built as an array. The finite element method (FEM) is generally used to analyze the characteristics of acoustic transducers. However, the FEM requires a longer analysis time as the model becomes larger, which makes it limited and less efficient for analyzing the cymbal array. In this study, a new equivalent circuit with higher efficiency and accuracy, comparable to that of the FEM, was proposed to analyze the performance of cymbal arrays. The equivalent circuit for the array was constructed by connecting the equivalent circuits of individual cymbal transducers in parallel with a radiation impedance matrix that included both the self- and mutual radiation characteristics of the array. The validity of the new equivalent circuit was verified by measuring the transmitting voltage response of a cymbal array specimen and comparing it with that calculated using the circuit. The comparison confirmed the efficiency of the equivalent circuit in analyzing the characteristics of the cymbal array. The proposed equivalent circuit can facilitate the design of a large array of cymbal transducers
Development of a Dual-Layer Structure for Cymbal Transducer Arrays to Achieve a Wider Bandwidth
Cymbal transducers are typically grouped and arranged in planar arrays. For projector arrays, a wide bandwidth on the transmitting voltage response (TVR) spectrum is required for better underwater communication and data transmission within a short time. The purpose of this study is to develop a wideband cymbal array by controlling the center-to-center (CTC) spacing between the cymbal transducers in the array. In the practical design of the array, due to the arrangement of elements in one layer, the minimum CTC spacing between the cymbals is constrained to the diameter of the cymbals in use. To overcome this limitation, we propose a new dual-layer array structure. Finite element analysis of the cymbal array showed that the bandwidth was generally inversely proportional to the CTC spacing. We explained the mechanism of this relationship using a theoretical analysis of the mutual radiation impedance between the cymbals in the array. Subsequently, we identified the optimum CTC spacing to achieve the widest possible bandwidth for the cymbal array. The validity of the wideband array design was verified through the fabrication and characterization of prototype arrays. We confirmed that the two-layered arrangement could significantly widen the bandwidth of the cymbal array while maintaining the TVR above a specified level
A System-Level Mechanism of Anmyungambi Decoction for Obesity: A Network Pharmacological Approach
Obesity is a low-grade systemic inflammatory disease involving adipocytokines. As though Anmyungambi decoction (AMGB) showed significant improvement on obesity in a clinical trial, the molecular mechanism of AMGB in obesity remains unknown. Therefore, we explored the potential mechanisms of action of AMGB on obesity through network pharmacological approaches. We revealed that targets of AMGB are significantly associated with obesity-related and adipocyte-elevated genes. Evodiamine, berberine, genipin, palmitic acid, genistein, and quercetin were shown to regulate adipocytokine signaling pathway proteins which mainly involved tumor necrosis factor receptor 1, leptin receptor. In terms of the regulatory pathway of lipolysis in adipocytes, norephedrine, pseudoephedrine, quercetin, and limonin were shown to affect adrenergic receptor-beta, protein kinase A, etc. We also found that AMGB has the potentials to enhance the insulin signaling pathway thereby preventing type II diabetes mellitus. Additionally, AMGB was discovered to be able to control not only insulin-related proteins but also inflammatory mediators and apoptotic regulators and caspases, hence reducing hepatocyte injury in nonalcoholic fatty liver disease. Our findings help develop a better understanding of how AMGB controls obesity
OUR-GAN: One-shot Ultra-high-Resolution Generative Adversarial Networks
We propose OUR-GAN, the first one-shot ultra-high-resolution (UHR) image
synthesis framework that generates non-repetitive images with 4K or higher
resolution from a single training image. OUR-GAN generates a visually coherent
image at low resolution and then gradually increases the resolution by
super-resolution. Since OUR-GAN learns from a real UHR image, it can synthesize
large-scale shapes with fine details while maintaining long-range coherence,
which is difficult with conventional generative models that generate large
images based on the patch distribution learned from relatively small images.
OUR-GAN applies seamless subregion-wise super-resolution that synthesizes 4k or
higher UHR images with limited memory, preventing discontinuity at the
boundary. Additionally, OUR-GAN improves visual coherence maintaining diversity
by adding vertical positional embeddings to the feature maps. In experiments on
the ST4K and RAISE datasets, OUR-GAN exhibited improved fidelity, visual
coherency, and diversity compared with existing methods. The synthesized images
are presented at https://anonymous-62348.github.io.Comment: 28 pages, 23 figure
Phytochemical and functional characterization of fermented Yerba mate using Rhizopus oligosporus
Abstract Solid-state fermentation (SSF) was used to enhance the bioactive compounds and biological properties of food materials, such as buckwheat, turmeric, and ginseng. This study was investigated the effects of SSF for up to 10 days using Rhizopus oligosporus on Yerba mate (Ilex paraguariensis St. Hilaire). The total phenolic content of Yerba mate rose to 20% after 1 day fermentation. The saponin contents of Yerba mate rose to 38% after 7 day fermentation. Furthermore, chlorogenic acid, caffeic acid, and caffeine levels were increased up to 27.74% by fermentation, as determined by UPLC-MS analysis. ORAC and FRAP assays showed that the antioxidant activities of Yerba mate were enhanced 1.9- and 1.14-fold after 1 day fermentation. In addition, its inhibitory activities against yeast α-glucosidase and nitric oxide release in LPS-stimulated RAW264.7 cells were higher than in the unfermented Yerba mate. Moreover, taste sensory analysis using an electronic tongue sensory system showed that the flavor of Yerba mate after 1 day fermentation was similar to that of the unfermented Yerba mate. These results suggested that solid fermentation using R. oligosporus is conducive to producing Yerba mate with enhanced biological properties
The effects of decomposition of CpZr(NMe2)3 on atomic layer deposition for high-k ZrO2 thin films
In this study, the thermal stability of cyclopentadienyl tris(dimethylamino)zirconium (CpZr(NMe2)3), a representative precursor for the deposition of ZrO2 films, was evaluated after exposure to thermal stress. As a result, we predicted that dimethylamine, and trimethylamine may be generated when CpZr(NMe2)3 was heated. These impurities affect the growth of film and the properties of the film. In particular, by changing the vapor pressure of CpZr(NMe2)3, thin films with different characteristics are formed under the same process conditions, and consequently, the reliability of the device was also reduced. Therefore, this study demonstrates that the decomposition of precursors must be studied to develop new precursors and highly reliable thin films and devices. © 2022 The AuthorsTRU
Decomposition Characteristics of the TTIP (Tetraisopropyl Orthotitanate) Precursor for Atomic Layer Deposition
The decomposition of tetraisopropyl orthotitanate (TTIP), a representative precursor used in the atomic layer deposition (ALD) of titanium dioxide (TiO2) film, and the resulting changes in the thin film properties of the TiO2 film were investigated. TTIP was evaluated after exposure to thermal stress in an enclosed container. The vapor pressure results provide reasonable evidence that impurities are generated by the decomposition of TTIP under thermal stress. These impurities led to changes in the thermal properties of TTIP and changes in the growth rate, morphology, and composition of the thin film; in particular, these impurities increased the unstable oxidation states of Ti2+ (TiO) content in the TiO2 film. The changes in the properties of the TiO2 film resulting from the changes in the physical properties of TTIP led to a change in the properties of the device. We proved that the thermal stability of the precursor is a factor that can determine the reliability of the ALD process and the resulting thin film. Additionally, systematic evaluation of the precursor can provide useful information that can improve the development of the precursor and the consistency of the process
Stretchable N-Type High-Performance Polymers Based on Asymmetric Thienylvinyl-1,1-Dicyanomethylene-3-Indanone for Plastic Electronics
The development of new electron-accepting building blocks to construct high-performance n-type semiconducting polymers is essential for various organic optoelectronic devices. Herein, we have incorporated a newly formulated thienylvinyl-1,1-dicyanomethylene-3-indanone (TIC) electron-accepting monomer into a series of n-type low-band gap polymers alongside cyclopentadithiophene (CDT) and indacenodithiophene (IDT) comonomers. Controlling the regioregularity of the asymmetric TIC has produced regioisomeric polymer structures [semi-regioregular (s-PCDT-TIC and s-PIDT-TIC) and regiorandom (r-PCDT-TIC and r-PIDT-TIC)]. We conducted comparative studies for the regiochemistry control and CDT versus IDT repeating units: (i) The CDT-containing polymers have red-shifted absorption and higher absorptivity compared to the IDT-containing analogues. (ii) The varied regioregularity affects the optical features rather than the energy levels. (iii) All the polymers show excellent n-channel field-effect transistors, with electron mobility higher than 1.0 x 10(-2) cm(2) V-1 s(-1), despite their low-ordered crystallinity. (iv) Stretchable transistors with polymers can achieve high retention of electron mobilities under the external strain; specially, r-PCDT-TIC maintains 95% initial mobility at 100% strain. In addition, an n-type near-infrared organic phototransistor based on s-PCDT-TIC exhibits an excellent photoresponsivity, photodetectivity, and external quantum efficiency of 203 A W-1 , 8.1 x 10(12) Jones, and 2.42 x 10(4)%, respectively, at a wavelength of 838 nm
Targeted Deletion of Thymosin Beta 4 in Hepatic Stellate Cells Ameliorates Liver Fibrosis in a Transgenic Mouse Model
Liver fibrosis is the most common feature of liver disease, and activated hepatic stellate cells (HSCs) are the main contributors to liver fibrosis. Thus, finding key targets that modulate HSC activation is important to prevent liver fibrosis. Previously, we showed that thymosin β4 (Tβ4) influenced HSC activation by interacting with the Hedgehog pathway in vitro. Herein, we generated Tβ4 conditional knockout (Tβ4-flox) mice to investigate in vivo functions of Tβ4 in liver fibrosis. To selectively delete Tβ4 in activated HSCs, double-transgenic (DTG) mice were generated by mating Tβ4-flox mice with α-smooth muscle actin (α-Sma)-Cre-ERT2 mice, and these mice were administered carbon tetrachloride (CCl4) or underwent bile duct ligation to induce liver fibrosis. Tβ4 was selectively suppressed in the activated HSCs of DTG mouse liver, and this reduction attenuated liver injury, including fibrosis, in both fibrotic models by repressing Hedgehog (Hh) signaling. In addition, the re-expression of Tβ4 by an adeno-associated virus reversed the effect of HSC-specific Tβ4 deletion and led to liver fibrosis with Hh activation in CCl4-exposed mice treated with tamoxifen. In conclusion, our results demonstrate that Tβ4 is a crucial regulator of HSC activation, suggesting it as a novel therapeutic target for curing liver fibrosis