MKELM based multi-classification model for foreign accent identification.

The automatic identification of foreign accents can play a crucial role in various speech systems, including speaker identification, e-learning, telephone banking, and more. Additionally, it can greatly enhance the robustness of Automatic Speech Recognition (ASR) systems. Non-native accents in speech signals are characterized by distinct pronunciations, prosody, and voice characteristics of the speaker. However, automatically identifying foreign accents poses significant challenges, particularly in the context of multi-class modeling. Multi-classification models face difficulties in achieving high performance and dealing with computational challenges when confronted with multi-dimensional and unbalanced datasets, such as those with more than two accents. Furthermore, the choice of features remains a bottleneck problem for Foreign Accent Identification (FAID), further hindering performance in these tasks. Consequently, the accuracy of current systems is typically low. To address these challenges, this paper proposes a framework based on the Multi-Kernel Extreme Learning Machine (MKELM) model for the multi-classification of FAID. The MKELM model utilizes a novel weighted scheme to classify various non-native English accents, including Arabic, Chinese, Korean, French, and Spanish. The model first combines Mel-frequency cepstral coefficients (MFCCs) and prosodic features as input, trains pairwise binary classifiers independently, and subsequently employs a weighting scheme to distinguish between classes and identify accents. Through experiments, the proposed model achieves an accuracy rate of 84.72% using a paired weighting scheme. In contrast, the accuracy rate drops to 66.5% when employing the traditional non-weighted multi-classification scheme. A comparison with other models demonstrates the significant advantages of the proposed model in FAID multi-class classification, showcasing improved accuracy, reduced computational complexity (requiring fewer computations, faster learning rates, and shorter training time), and enhanced stability compared to state-of-the-art classification methods.

Fabrication of wafer-size monolayer close-packed colloidal crystals via slope self-assembly and thermal treatment.

We developed a simple and general approach for constructing a wafer-scale monolayer, close-packed polystyrene (PS), and SiO2 sphere arrays, namely colloidal crystals, which have significant potential in various applications. The method combines slope self-assembly and thermal treatment to achieve large-area and high-quality colloidal crystal with a proper slant angle (θ) and latex concentration (volume fraction, φ). The dependence of the structures of colloidal crystals on a dispersion system was also investigated. Moreover, a theoretical analysis of the slope self-assembly method was proposed. In addition, we applied the method to assemble PS spheres on different kinds of substrates, which indicates that the method is a versatile and reliable way to fabricate monolayer colloidal crystals.

Dopant Distribution in Atomic Layer Deposited ZnO:Al Films Visualized by Transmission Electron Microscopy and Atom Probe Tomography.

The maximum conductivity achievable in Al-doped ZnO thin films prepared by atomic layer deposition (ALD) is limited by the low doping efficiency of Al. To better understand the limiting factors for the doping efficiency, the three-dimensional distribution of Al atoms in the ZnO host material matrix has been examined on the atomic scale using a combination of high-resolution transmission electron microscopy (TEM) and atom probe tomography (APT). Although the Al distribution in ZnO films prepared by so-called "ALD supercycles" is often presented as atomically flat δ-doped layers, in reality a broadening of the Al-dopant layers is observed with a full-width-half-maximum of ∼2 nm. In addition, an enrichment of the Al at grain boundaries is observed. The low doping efficiency for local Al densities > ∼1 nm-3 can be ascribed to the Al solubility limit in ZnO and to the suppression of the ionization of Al dopants from adjacent Al donors.

Atomic Layer Deposition of In2O3:H from InCp and H2O/O2: Microstructure and Isotope Labeling Studies.

The atomic layer deposition (ALD) process of hydrogen-doped indium oxide (In2O3:H) using indium cyclopentadienyl (InCp) and both O2 and H2O as precursors is highly promising for the preparation of transparent conductive oxides. It yields a high growth per cycle (>0.1 nm), is viable at temperatures as low as 100 °C, and provides a record optoelectronic quality after postdeposition crystallization of the films ( ACS Appl. Mat. Interfaces , 2015 , 7 , 16723 - 16729 , DOI: 10.1021/acsami.5b04420 ) . Since both the dopant incorporation and the film microstructure play a key role in determining the optoelectronic properties, both the crystal growth and the incorporation of the hydrogen dopant during this ALD process are studied in this work. This has been done using transmission electron microscopy (TEM) and atom probe tomography (APT) in combination with deuterium isotope labeling. TEM studies show that an amorphous-to-crystalline phase transition occurs in the low-temperature regime (100-150 °C), which is accompanied by a strong decrease in carrier density and an increase in carrier mobility. At higher deposition temperatures (>200 °C), enhanced nucleation of crystals and the incorporation of carbon impurities lead to a reduced grain size and even an amorphous phase, respectively, resulting in a strong reduction in carrier mobility. APT studies on films grown with deuterated water show that the incorporated hydrogen mainly originates from the coreactant and not from the InCp precursor. In addition, it was established that the incorporation of hydrogen decreased from ∼4 atom % for amorphous growth to ∼2 atom % after the transition to crystalline film growth.

Kinetic theory approach to modeling of cellular repair mechanisms under genome stress.

Under acute perturbations from outer environment, a normal cell can trigger cellular self-defense mechanism in response to genome stress. To investigate the kinetics of cellular self-repair process at single cell level further, a model of DNA damage generating and repair is proposed under acute Ion Radiation (IR) by using mathematical framework of kinetic theory of active particles (KTAP). Firstly, we focus on illustrating the profile of Cellular Repair System (CRS) instituted by two sub-populations, each of which is made up of the active particles with different discrete states. Then, we implement the mathematical framework of cellular self-repair mechanism, and illustrate the dynamic processes of Double Strand Breaks (DSBs) and Repair Protein (RP) generating, DSB-protein complexes (DSBCs) synthesizing, and toxins accumulating. Finally, we roughly analyze the capability of cellular self-repair mechanism, cellular activity of transferring DNA damage, and genome stability, especially the different fates of a certain cell before and after the time thresholds of IR perturbations that a cell can tolerate maximally under different IR perturbation circumstances.

Effect of Da-Cheng-Qi decoction on the pharmacokinetics of ranitidine in rats.

Da Cheng Qi decoction (DCQD) is composed of Dahuang, Houpu, Zhishi and Mangxiao. It is a formula created under the theory of Chinese medicine to purge the 'evil heat' in the gastrointestitinal tract, which arises from the ileus and acute pancreatitis. The present study was conducted to evaluate the herb-drug interaction between DCQD and ranitidine, which are often co-administered in clinical practice. Ranitidine was administered orally alone or together with DCQD to rats, and plasma ranitidine concentrations were measured by HPLC. Following oral administration, ranitidine plasma levels revealed curves characterized by peaks at 1.8 and 4.2 h corresponding to ranitidine alone and ranitidine with DCQD at mean concentrations of 16.315 and 1.455 microg/mL, respectively. After ranitidine was orally dosed alone or with DCQD, the half-lives were 1.787 and 3.758 h, while the area under the concentration-time curve (0-12 h) was 28.083 and 9.826 microg/L h, respectively, suggesting that DCQD might significantly affect the pharmacokinetics of ranitidine in rats. When physicians or pharmacists administer DCQD and ranitidine, they must make a careful effort to adjust the dosage of the drug and Chinese decoction, or avoid the herb-drug co-administration.