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A New Probe into the Teaching of Listening for Chinese as a Foreign Language.
Zhang,Tingting 조선대학교 국제문화연구원 2018 국제문화연구 Vol.11 No.1
News listening course is an essential course in teaching Chinese as a foreign language. However, due to the influence of mother tongue, the differences between classroom and real language and the influence of cultural factors, students are learning a lot and often lose confidence. By the results of the questionnaire survey, this paper puts forward some methods for the teaching content and means of the news listening class and proposes to establish a news listening corpus. It is hoped that these measures can help learners to master the news information quickly, improve their listening ability, develop their understanding of Chinese culture, and understand the problems of contemporary society.
Mathematical framework for a new micro-electrical impedance tomography system
Tingting Zhang,EunJung Lee,Jin Keun Seo,Eung Je Woo 한국산업응용수학회 2010 한국산업응용수학회 학술대회 논문집 Vol.5 No.2
This work presents a mathematical framework of a new microscopic electrical impedance tomography (micro-EIT) system which aims to pro¬duce cross-sectional conductivity images of a biological tissue sample or cells inside a small hexahedral container. Unlike conventional micro-EIT systems which have much in common with a standard EIT system, the proposed micro-EIT system has a unique electrode configuration and associated data collection method. Two sides of the container facing each other are fully covered by driving electrodes. Injecting current between this driving electrode pair, we can create a uniform parallel current density distribution inside the container when it is filled with a homogeneous saline. We install many miniature electrodes on the other two sides and the bottom of the container for voltage measurements. The top of the container is open for sample manipulations. This electrode configuration provides a large number of voltage measurements from the three surfaces subject to one current injection. In this paper, we provides a mathematical framework of this novel micro-EIT system for the development of image re-construction algorithms. Taking advantage of the uniform parallel current density, we construct an inversion formula of the conductivity from the acquired boundary voltage. Employing the reciprocity theorem for the electrode configuration, we compute a sensitivity matrix to reconstruct cross-sectional conductivity images. Numerical simulations show that the proposed algorithm successfully reconstructs conductivity images of multiple anomalies. In terms of the image quality, the new micro-EIT system is advantageous over a conventional EIT method adopting multiple current injection patterns. For experimental studies to be followed, we suggest micro-EIT system developments based on the proposed novel idea.
Tingting Zhang,Junlian Yin,Dezhong Wang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11
In this study, the bubble separation behavior in a gas–liquid separator is numerically investigated on the basis of the Euler–Lagrange approach, in which the forces acting on bubbles in a swirling flow field are modeled to calculate the trajectories of the bubbles. By adopting this approach, the effects of five parameters, namely, back pressure, Reynolds number, bubble diameter, void fraction, and swirl number, on separation performance in terms of pressure loss, separation efficiency, separation length, and split ratio are computed and analyzed. On the basis of the analysis, correlations of separation length with the two main parameters are established, which can serve as a basis for the optimal design of separator.
Zhang, Tingting,Lee, Eunjung,Seo, Jin Keun Institute of Physics 2014 Inverse problems Vol.30 No.4
<P>Trans-admittance mammography (TAM) is a bioimpedance technique for breast cancer detection. It is based on the comparison of tissue conductivity: cancerous tissue is identified by its higher conductivity in comparison with the surrounding normal tissue. In TAM, the breast is compressed between two electrical plates (in a similar architecture to x-ray mammography). The bottom plate has many sensing point electrodes that provide two-dimensional images (trans-admittance maps) that are induced by voltage differences between the two plates. Multi-frequency admittance data (Neumann data) are measured over the range 50 Hz–500 kHz. TAM aims to determine the location and size of any anomaly from the multi-frequency admittance data. Various anomaly detection algorithms can be used to process TAM data to determine the transverse positions of anomalies. However, existing methods cannot reliably determine the depth or size of an anomaly. Breast cancer detection using TAM would be improved if the depth or size of an anomaly could also be estimated, properties that are independent of the admittivity contrast. A formula is proposed here that can estimate the depth of an anomaly independent of its size and the admittivity contrast. This depth estimation can also be used to derive an estimation of the size of the anomaly. The proposed estimations are verified rigorously under a simplified model. Numerical simulation shows that the proposed method also works well in general settings.</P>
Mathematical framework for a new microscopic electrical impedance tomography system
Tingting Zhang,Eunjung Lee,Eung Je Woo,Jin Keun Seo 한국산업응용수학회 2010 한국산업응용수학회 학술대회 논문집 Vol.5 No.1
In this work, we propose a mathematical framework for a new microscopic electrical impedance tomography (micro-EIT) system which aims to visualize admittivity distributions within a hexahedral container, where we place small biological samples with a background solution. We inject a projection current by placing a pair of wide driving electrodes covering the entire surface of two facing sides (left and right) of the container. We measure the resulting boundary potential using sensing many electrodes that are placed on the remaining three sides excluding the top surface. The inverse problem is to reconstruct the admittivity distributions inside the container from the boundary voltage measurements. We proposed a reconstruction method using linearization technique. Reconstructed image quality and errors are shown by numerical simulations.
Tingting Zhang,Po-Ju Chen 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07
This study focuses on the digital generation in China and their engagement in social media to co-create values with firms. The study employed a qualitative research approach to first develop a social media co-creation value scale. This was followed by motivational analysis of social media engagement to co-create values. A spectrum of utilitarian and hedonic motives related to value co-creation behaviors via social media were then identified. Many theoretical and practical implications are provided based on the study findings.
SPECTROSCOPIC ADMITTIVITY IMAGING OF BIOLOGICAL TISSUES
TINGTING ZHANG,TUSHAR KANTI BERA,EUNG JE WOO,JIN KEUN SEO 한국산업응용수학회 2014 Journal of the Korean Society for Industrial and A Vol.18 No.2
Medical imaging techniques have evolved to expand our ability to visualize new contrast information of electrical, optical, and mechanical properties of tissues in the human body using noninvasive measurement methods. In particular, electrical tissue property imaging techniques have received considerable attention for the last few decades since electrical properties of biological tissues and organs change with their physiological functions and pathological states. We can express the electrical tissue properties as the frequency-dependent admittivity, which can be measured in a macroscopic scale by assessing the relation between the timeharmonic electric field and current density. The main issue is to reconstruct spectroscopic admittivity images from 10 Hz to 1 MHz, for example, with reasonably high spatial and temporal resolutions. It requires a solution of a nonlinear inverse problem involving Maxwell’s equations. To solve the inverse problem with practical significance, we need deep knowledge on its mathematical formulation of underlying physical phenomena, implementation of image reconstruction algorithms, and practical limitations associated with the measurement sensitivity, specificity, noise, and data acquisition time. This paper discusses a number of issues in electrical tissue property imaging modalities and their future directions.