Exploration of CNN-based and RNN-based neural networks for Text Classification

SUN JING 아주대학교 일반대학원 2018 국내석사

Nature language processing (NLP) is an important research field in artificial intelligence compromising linguistics, computer science, and mathematics. Text classification is a basic task in various NLP tasks, which is the process of assigning a piece of text to one or more classes. Nowadays, the most widely used approaches for text classification are based on neural networks, namely convolutional neural networks (CNN) and recurrent neural networks (RNN). CNN is a class of deep, feed-forward neural networks which uses a variation of multiple layers of perceptron in order to minimize calculation. RNN is proposed to take advantage of sequential information, whose current output is not only influenced by the current input but also the previous input. This thesis explores both CNN and RNN based methods for text classification. For CNN based model, gate mechanism is introduced to better capture the information of the input, residual connection and batch normalization technics are also used for gaining further improvement. For RNN based method, we explored the different impacts of four kinds of different advanced RNN units, namely unidirectional Long short-term memory (LSTM), bidirectional LSTM, unidirectional Gated recurrent unit (RGU) and bidirectional GRU combined with hierarchical attention mechanism for text classification.

전산회계 교육에서 자기조절학습능력이 학습몰입, 학습자만족도 및 학업성과에 미치는 영향 : 중국 대학생을 중심으로

SUN JING 한밭대학교 대학원 2022 국내석사

The evolution of the information society that started at the end of the 20th century has recently declared the beginning of the fourth industrial revolution and is causing many changes in our society. Business management is also required to innovate based on information technology in line with the changes of the times, and many changes are taking place in business processing methods and decision-making methods. Now, corporate accounting goes beyond simple computerization, and ERP and cloud computing are being promoted. Therefore, the educational method of accounting in universities is also changing based on information technology. Computerized accounting uses computer hardware and software-based information technology to record corporate accounting information as well as to produce financial information useful for decision-making by internal and external users of the company. In particular, in a business environment where competition between companies transcends industries and borders, financial information for quick decision-making is required in real time, so the need for computerized accounting is increasingly emerging. Therefore, many scholars have emphasized the importance of the education on computerized accounting in universities and many studies have been conducted. Until now, most of the research on computerized accounting education was based on the education and training transfer model. Many researchers have studied the effects of perceived usefulness in computerized accounting education, learners' self-efficacy and learning motivation, learner satisfaction, and learning immersion on academic performance. Self-regulated learning ability can be defined as the ability of learners to plan, implement, and evaluate their own learning process. The concept of self-regulated learning ability is treated as an important factor affecting academic achievement in the field of pedagogy and consists of cognitive control, motivational control and behavioral control as sub-factors. Studies on self-regulated learning strategies have been conducted mainly on elementary, middle, and high school students, but relatively few studies on college students have been conducted. In addition, research on self-regulated learning ability and academic achievement has been conducted in engineering, nursing, and language arts, as well as in the field of pedagogy. In this study, we consider the effect of self-regulated learning strategies in computerized accounting education. To this end, we develop a research model and establish research hypotheses to investigate the effect of self-regulated learning strategies on learning flow, learner satisfaction and academic performance in computerized accounting education. We also consider hypotheses to investigate the mediating effect of learner satisfaction and learning flow in the influence relationship between the self-regulated learning ability and learning performance in computerized accounting education. In particular, in this study, we conduct the empirical analysis in order to verify the research hypotheses for students who completed computerized accounting courses at Chinese universities. To this end, we conduct survey Chinese university students who have taken computerized accounting courses, and conduct a regression analysis to test the research hypotheses. We summarize the results of the verification of the research hypotheses as follows. First, it was found that self-regulated learning ability in computerized accounting education had a positive effect on academic performance. In addition, although cognitive control, motivational control, and behavioral control, which are sub-factors of self-regulated learning ability, all had a significant effect on academic performance, it was found that motivational control had a higher influence than cognitive control and behavioral control. Second, in computerized accounting education, self-regulated learning ability was found to have a positive effect on learner satisfaction and learning immersion. In addition, all of cognitive control, motivational control and behavioral control, which are sub-factors, were found to have a significant effect on learner satisfaction and learning immersion, but cognitive control and behavioral control were found to have a higher influence than motivational control. Third, it was found that learner satisfaction and learning immersion positively affect academic performance in computerized accounting education, which is consistent with previous studies. Fourth, in the relationship between self-regulated learning ability and academic performance, learning satisfaction was found to play a partial mediating role, but there was no mediating effect of learning immersion. 20세기말부터 시작된 정보화 사회로의 진화는 최근 4차 산업혁명의 시작을 선언하게 되었으며 우리 사회에 많은 변화를 일으키고 있다. 기업의 경영도 시대적 변화에 맞추어 정보기술을 바탕으로 혁신을 요구받고 있으며 업무처리 방식과 의사결정 방식에 많은 변화가 일어나고 있다. 이제 기업의 회계업무는 단순한 전산화를 뛰어넘어 ERP의 도입 및 클라우드 컴퓨팅이 추진되고 있다. 따라서 대학에서 이루어지는 회계학에 대한 교육방식도 정보화 기술을 바탕으로 변화하고 있다. 전산회계란 컴퓨터 하드웨어와 소프트웨어 기반의 정보기술을 이용하여 기업의 회계정보를 기록할 뿐만 아니라 기업의 내·외부 이용자들의 의사결정에 유용한 재무적 정보를 산출하는 것이다. 특히 기업 간 경쟁이 산업과 국경을 초월하여 이루어지는 경영환경에서 신속한 의사결정을 위한 재무적 정보가 실시간으로 요구되므로 전산회계의 필요성이 점점 더 부각되고 있다. 따라서 대학에서 이루어지는 전산회계에 대한 교육의 중요성이 더욱 더 강조되고 있으며 많은 연구가 진행되고 있다. 그동안 전산회계 교육에 대한 연구는 교육훈련 전이모형에 기반을 둔 연구가 대부분 이었다. 전산회계 교육에 대한 인지된 유용성, 학습자의 자기효능감 및 학습동기, 학습자 만족도 및 학습 몰입 등이 학업성과에 미치는 영향관계에 대한 연구가 많은 연구자들에 의해 진행되어 왔다. 자기조절학습능력은 학습자가 스스로 학습과정을 계획하고 실행하고 평가하는 능력으로 정의할 수 있다. 자기조절학습능력이란 개념은 교육학 분야에서 학업성취도에 미치는 중요한 요인으로 다뤄지고 있으며 하위요인으로 인지조절, 동기조절, 행동조절로 구성되어 있다. 자기조절학습전략에 대한 연구는 초, 중, 고등학생을 대상으로 주로 진행되었으나 대학생을 대상으로 한 연구는 상대적으로 적은 편이다. 또한 자기조절학습능력이 학업성취도에 대한 연구는 교육학 분야 외에도 공학, 간호학, 어학 등에서 수행되고 있으며 최근 코로나 팬데믹의 등장으로 활성화된 온라인교육 분야에서도 수행되었다. 본 연구에서는 전산회계 교육에서 자기조절학습전략의 효과를 알아보기 위한 연구를 진행하였다. 이를 위하여 전산회계교육에서 자기조절학습능력이 학습성과에 미치는 영향과 이들 변인의 영향관계에서 학습자 만족도와 학습몰입의 매개효과를 알아보기 위한 연구모형을 개발하고 연구가설을 수립하였다. 특히, 이 연구에서는 중국 대학에서 전산회계 교과목을 이수한 학생들을 대상으로 연구가설의 검증을 위한 실증분석을 실시하였다. 이를 위하여 전산회계 과목을 수강한 중국 대학의 학생들을 대상으로 설문조사를 실시하였으며 연구가설의 검정을 위하여 회귀분석을 실시하였다. 연구가설에 대한 검증 결과를 요약하면 다음과 같다. 첫째, 전산회계 교육에서 자기조절학습능력은 학업성과에 정의 영향을 미치는 것으로 나타났다. 또한 자기조절학습능력의 하위요인인 인지조절, 동기조절, 행동조절 모두 학업성과에 유의미한 영향을 미치는 것으로 나타났으나 동기조절이 인지조절과 행동조절보다 영향관계가 높은 것으로 나타났다. 둘째, 전산회계 교육에서 자기조절학습능력은 학습자만족도와 학습몰입에 정의 영향을 미치는 것으로 나타났다. 또한 하위요인인 인지조절, 동기조절, 행동조절 모두 학습자만족도와 학습몰입에 유의미한 영향을 미치는 것으로 나타났으나 인지조절과 행동조절이 동기조절보다 영향관계가 높은 것으로 나타났다. 셋째, 전산회계 교육에서 학습자만족도와 학습몰입은 학업성과에 정의 영향을 미치는 것으로 나타났으며 이는 기존의 선행연구에서와 일치하는 결과이다. 넷째, 자기조절학습능력과 학업성과의 영향관계에서 학습자만족도는 부분매개역할을 하는 것으로 나타났으나 학습몰입의 매개효과는 없는 것으로 나타났다.

중국인 한국어 학습자를 위한 문화 간 의사소통 중심 교재 연구

SUN JING 경희대학교 대학원 2018 국내박사

언어의 습득은 곧 그 언어를 모국어로 사용하는 사람들의 문화를 습득하는 것이고 문화를 습득하는데 있어서 가장 핵심적인 과정은 언어를 습득하는 것이라고 할 수 있다. 즉 인간의 언어에는 그 언어를 사용하는 사회의 문화가 담겨져 있어서 어떤 언어를 사용한다는 것은 그 언어를 쓰고 있는 사회의 문화를 말하는 이런 점에서 외국어를 배운다는 것은 그 나라의 문화를 배우는 것이므로 어떤 외국어에 능통하다는 것은 그 나라의 문화를 잘 알고 있다는 것을 뜻한다. 특히 다른 문화를 갖고 있는 사람들이 서로 접촉하면서 갈등, 모순, 오해가 생기며, 또한 외국인 학습자는 한국어를 배웠을 때 이문화의 적응 발달 단계를 경험할 수밖에 없는 상황에서 사람들이 어떻게 이문화를 빨리 적응하고 사람들 간에 효율적이고 적절하게 의사소통을 할지는 한국어 문화 학습의 관건이 되었다. 이 바탕으로 문화 간 의사소통능력 이론이 드러났다. 한국어 교재는 한국어 교실에서 학습자들이 한국어와 한국어 문화를 학습하는 핵심 도구이라고 볼 수 있으며, 대부분 의사소통을 중심으로 삼아 학습자의 언어 능력을 함양하는 것만 집중하였다. 하지만, 한국어 문화에 대한 학습, 특히 문화 차이로 인해 야기한 여러 문제에 대해 학습자들이 어떻게 극복하고 최종적으로 효율적이고 적절하게 의사소통을 하는지에 관한 내용은 교재에서 거의 언급하지 못한다는 점에서 아쉬움이 남았다. 이러한 상황에서 문화 간 차이로 인해 야기한 문제들을 완화할 수 있는 문화 간 의사소통능력을 함양하기 위해 현재 한중 양국에서 사용되고 있는 주요 문화 교재를 분석하고, 또 학습자 요구 분석을 통해 현지 문화교육 교재의 개선 방안을 제시하는 데 있어서 본고의 목적이다. 이 목적을 둘러싸여 본고는 아래와 같이 연구 방법을 제시하였다. 제 1장에서는 본고의 연구의 필요성과 목적을 제시하고, 주제와 관련된 선행연구를 살펴보고자 했다. 기존의 선행연구에 대한 검토를 통해 한국어 교육에서 문화 간 의사소통을 위한 문화교육 교재 중요성을 알아볼 수 있으며, 본 연구의 목적과 필요성을 밝혔다. 그 다음으로 본 연구를 위한 연구 방법과 연구 절차를 설명하고자 하였다. 제2장 이론적 배경에서 한국어 문화교육 교재 개발을 위해 한국어 문화교육의 필요성을 살펴보고, 문화 간 의사소통능력에 관련된 대표적인 학자(Byram, Fantini, Deardoff )의 이론을 중심으로 문화 간의 의사소통능력의 정의와 구성요소는 무엇인지, 및 어떤 방법으로 문화 간 소통능력을 함양하는지를 검토하고자 하였다. 그 다음으로 한국어 문화교육과 문화 간 의사소통능력 함양 간의 관계는 무엇인지를 논의하였다. 이 부분에서 본고는 Byram, Fantini, Deardoff의 이론을 종합하여 문화 간 의사소통능력의 정의 및 구성요소에 대해 본고의 관점을 제시하였다. 그 후에 이러한 관점에 따라 제3장에서 중국인 한국어 학습자에 대한 요구 조사와 현지 한국어 교재에서의 문화교육의 개선을 위한 교재에 대한 분석을 진행하였다. 제3장에서는 한국어 문화 교재 개발을 위한 학습자 요구분석을 위해 이 부분은‘요구 분석 절차와 방법’, ‘요구 분석 설문 설계’, ‘조사의 결과 분석’으로 나누어진다. 분석 결과를 바탕으로 중국인 한국어 학습자가 문화 간 의사소통능력의 파악 상황 및 중국인 학습자를 선호하는 문화 항목에 따라 제5장의 문화교육 교재 방안에 기준을 제공하였다. 제4장에서는 한국어 문화교육의 개선을 위한 교재 분석이다. 본고는 내용 분석의 대상(어떤 교재를 대상으로 분석할 것), 연구의 문제, 연구방법, 분석 기준, 및 절차를 정하고 선정된 한중 양국의 문화교육 교재 내용을 분석했다. 위에 제 2장에서 도출한 관점(문화 간 의사소통능력의 구성요소)에 따라 문화교육 교재에 대해 분석했다. 문화 간 의사소통능력에 관한 내용은 선정된 한중 양국의 문화교육 교재에서 어떠한 방식으로 나타나는지를 논의하고, 이러한 논의는 제5장 본고의 교재 방안을 기준을 제공해 주었다. 제5장에서는 문화 교재 방안의 개발을 위해 이 부분은‘한국어 문화 교재의 기본 방향과 개발 원리’, ‘한국어 문화교육의 목표 선정’, ‘ 한국어 문화교육의 교수요목 설계’, ‘효과적인 문화교육을 위한 단원 구성’ 3가지 세분 부분으로 나누어진다. 이 부분에서 제3장이 제시한 한중 양국 문화교육 교재의 비교분석 결과(양국 문화교육 교재에서 문화 간 의사소통능력 함양을 위한 교육 내용의 양상 및 본고의 논의) 및 제4장에서 중국인 한국어 학습자에 대한 요구조사 결과(중국인 한국어 학습자의 문화 간 의사소통능력에 대한 파악 상황 및 중국인 학습자의 문화항목에 대한 관심도의 조사 결과)를 종합적으로 검토한 뒤, 본고는 ‘한국어 문화교육 교수요목 설계’의 부분과 ‘효과적인 문화교육을 위한 단원 구성’의 부분을 제기하였다. 마지막으로 6장에서는 본고가 중국인 한국어 학습자의 문화 간 의사소통능력 함양을 위한 문화교육 교재 내용을 개선하는 데 있어서 그 의의를 다시 살펴보고, 본 연구의 전체 내용을 종합적으로 정리하고 요약할 것이며, 본 연구의 목적에 도달할지 다시 확인하고자 한다. 그리고 연구의 한계를 밝히고, 후속 연구에 대해서 제언하였다. 한국어 학습 할 때 ‘교재는 교육 시작이자 전부이다’라는 명제도 있었지만, 여기서는 이 명제를 맞는지를 넘어 문화 간 의사소통능력 함양을 위한 문화교육의 중요성이 뚜렷하게 보이면서 문화교육 교재는 한국어 학습에서 아주 중요한 것이라는 것을 우리가 알 수 있다. 또한, 지금까지 특정한 학습자(중국인)를 위해 문화교육 교재를 개발하는 것이 거의 없으므로 본 연구는 문화 간 의사소통을 위해 문화교육 교재의 설정 그 자제라도 의의가 아주 크다고 본다. 뿐만 아니라 문화 간 의사소통능력의 함양은 굉장히 어려운 과정이기 때문에 본고는 학습자가 한국어 문화에 대한 관심도에 따라 교재에서 문화범위의 비중을 다시 선정한 뒤, 관심도가 많은 주체에서부터 문화 간 의사소통능력을 함양한다는 방안을 제시한다는 점에서 의의도 찾을 수 있을 것이다. It can be said that language acquisition is the acquisition of the culture of the people who use that language as a native language and that in the culture acquisition, the most essential process is the language acquisition. Namely, the language the human beings using includes the culture of that society where the language is being used. The use of the language means the culture of the society where the language is being used, so the learning of the foreign language means the learning of the culture of that country. To put it in another word, being proficient in the language means that the person knows well about the culture of that country. Especially, the people who have different cultural background will have conflicts, contradictions and misunderstanding when they have contact. In addition, for foreign learners, how they can adapt to different culture quickly and how they communicate efficiently and appropriately in the situation where they have to experience the adaptation and development phase of different culture when they are learning the Korean language are the key to the Korean culture study. Based on this, intercultural communicative ability theory emerged. Korean textbook can be seen as the essential tool of the learning of Korean and Korean culture in the Korean class. Taking the communication as the core, the cultivation of the linguistic ability was the center. However, the learning of Korean culture, how to solve several problems resulting from the cultural differences eventually, how to communicate efficiently and appropriately were not included in the textbook. In this situation, for the cultivation of intercultural communicative ability that can solve the problems resulting from the cultural differences, the main cultural textbooks mainly used in China and Korea were analyzed. Furthermore, through the learner demand analysis, this paper is aimed to propose the improvement plans of the cultural education textbooks. For this purpose, the research methods of this paper are presented as follows. In chapter 1, the necessity and purpose of this paper were presented. Previous studies related to the subjects were reviewed. Through the review of previous studies, the importance of the cultural education textbook for intercultural communication in the Korean education was figured out. The purpose and necessity of this study were revealed. Afterward, the research method and procedure of this study was explained. In chapter 2, in the theoretical background, the necessity of the Korean cultural education for the development of Korean cultural education textbook was examined. The definition, components of the intercultural communicative ability and the method of cultivating intercultural communicative ability were examined by focusing on the theories of representative scholars(Byram, Fantini, Deardoff) related to the intercultural communicative ability. The relationship between the Korean cultural education and the intercultural communicative ability was discussed. In this part, this paper integrated the theories of Byram, Fantini and Deardoff and proposed the perspectives of this paper related to the definition and components of intercultural communicative ability. According to these perspectives, in chapter 3, the survey on Chinese Korean learners’ demands and the textbooks for the improvement of cultural education based on current Korean textbooks were analyzed. In chapter 3, for learners’ demand analysis in the Korean cultural textbook development, it was divided into ‘demand analysis procedure and method’, ‘demand analysis survey design’ and ‘survey result analysis’. Based on the analysis results, according to the understanding Chinese Korean learners intercultural communicative ability and the cultural subjects that the Chinese learners preferred, the standard of cultural education textbook plans was provided. The chapter 4 was the textbook analysis for the improvement of Korean cultural education. This paper analyzed the contents of the selected cultural education textbooks in China and Korea by establishing the analysis subjects(what textbooks to analyze), research subjects, research methods, analysis standard and procedure. According to the perspectives from chapter 2(the components of intercultural communicative ability), the cultural education textbooks were analyzed. The problem that how the contents related to intercultural communicative ability were presented in the cultural education textbooks in China and Korea was discussed. This discussion provided the standard of the textbook plans in chapter 5. In chapter 5, for the development of cultural textbook plans, it is divided into ‘the basic direction and development principles of the Korean cultural textbooks’, ‘the establishment of the purpose of Korean cultural education’, ‘the design of the syllabus of Korean cultural education’ and ‘the unit construction for effective cultural education’. After examining the comparison results of the cultural education textbook in China and Korea discussed in chapter 3(the education contents and the discussion of this paper for the cultivation of intercultural communicative ability in Korean and Chinese cultural education textbooks) and the results of the survey on Chinese Korean learners’ demands in chapter 4(Chinese Korean learners’ understanding of intercultural communicative ability and the survey results of the cultural subjects that Chinese learners preferred), this paper proposed ‘the design of the syllabus of Korean cultural education’ and ‘unit construction for effective cultural education’. Finally, in chapter 6, the implications of this paper in the improvement of cultural education textbook contents for the cultivation of Chinese Korean learners’ intercultural communicative ability was examined. The contents of this paper will be generally organized and summarized. Whether the purpose of this paper is realized will be confirmed again. The limitations of this research will be revealed and the discussions in the future studies will be suggested. Although there is a saying that ‘the textbook is the start and the whole of the education’ when studying Korean, despite this saying, the importance of the cultural education for the cultivation of intercultural communicative ability is very clear. Cultural education textbooks are very important in Korean learning. In addition, till now, there was almost none development of cultural education textbooks for specific learners(Chinese), so it is significant that this study discussed the development of cultural education textbooks for intercultural communication. Moreover, the cultivation of intercultural communicative ability is a very difficult process, so this paper has the significance to propose the plans of cultivating the intercultural communicative ability from the subjects that the learners have much interest in, after modifying the proportion of the cultural range in the textbooks according to the interest rate of the Chinese Korean learners in Korean culture.Key wordsKorean cultural education, the communicative ability between cultures, attitude, techniques, knowledge, recognition, the culture classification by grade, culture education plan, the development of cultural textbook

중국의 반한류에 관한 연구 : 한한령 이후 드라마에 대한 반한류를 중심으로

SUN JING WEN 홍익대학교 대학원 2023 국내석사

Interactive effects of metacognitive awareness and anxiety on listening proficiency of Chinese EFL learners

Sun, Jing 전주대학교 대학원 2024 국내박사

Individual differences in the EFL listening process, most distinctively, the metacognitive and affective factors, have won a growing concern among modern scholars with the prevalence of learner-centered teaching. Enhancing metacognitive awareness is considered an accelerating factor in listening skill development and empowers listeners’ autonomy. Anxiety is believed to be one of the affective factors that hinder the listening process the most. Previous studies have revealed that listening metacognitive awareness (LMA) and foreign language listening anxiety (FLLA) are related to listening performance, respectively. Interestingly, the interaction among LMA, FLLA, and English listening proficiency (ELP) in the context of English major university students in China is not paid much attention to. This study examines the relationship among university students’ LMA, FLLA, and ELP. Besides, the impact of LMA and FLLA on the high- and low-proficiency groups of English listening is discussed. Rather, what is of great interest is to describe the predicting power of LMA and FLLA on listening proficiency. More importantly, the potential moderating effect of LMA on the relationship between FLLA and ELP is explored. To this end, 276 English major senior students from Shanxi/China were recruited to attend the experiment. The Metacognitive Awareness Listening Questionnaire (MALQ) was administered to see participants’ LMA. Later, data on participants’ listening anxiety was gained using the Foreign Language Listening Anxiety Scale (FLLAS). Their listening proficiency level was measured by the listening section of College English Test Band 6 (CET-6). To address the research questions, quantitative data analysis techniques, including Descriptive statistics analysis, Pearson correlation, Binary logistic regression, Multiple regression analysis, and Hierarchical regression analysis, were run to analyze the data. The results show that selected university students’ listening metacognitive awareness and listening anxiety are all at a higher level on the whole. In contrast, their listening proficiency is relatively low. There is a significant and positive correlation between the participants’ LMA and listening proficiency. A significant and negative correlation between their FLLA and listening proficiency is observed. As for the impact of LMA on the participants’ high-and-low listening proficiency grouping, sub-factors of problem-solving and mental translation show significance. Two sub-factors of FLLA also exhibit importance in grouping high and low listening proficiency. Later, Multiple regression analysis yields 26.3% of the variance in listening proficiency, which can be explained by LMA and FLLA altogether. It also demonstrates that LMA has more predicting power for participants’ English listening proficiency than FLLA. One possible reason for the comparatively weaker explanation of FLLA is verified by the moderate analysis that LMA moderates the negative power of FLLA for English listening proficiency. Finally, implications and suggestions are discussed based on these findings.

중국 심천주식시장에서 환노출이 주가에 미치는 영향

Sun, Jing Wen 충북대학교 2010 국내석사

Since the reform of RMB(Ren Min Bi) exchange rates in July 21th, 2005, RMB exchange rates has appreciated 8% by the end of 2007. At the same time, the Shanghai composite index has been to 6124 points on October 16th, 2007 from 998 points on June 6th, 2005. Stock prices continued to rise while the appreciation of RMB exchange rate accelerated. Whether there is a link between RMB exchange rate and stock prices? This thesis makes a comprehensive analysis between the exchange rates and stock prices; then with China's reality, this paper analyzes the relation exsiting between RMB exchange rate and stock prices. This thesis is examines the relationship between foreign exchange exposure and stock price of China industry index. It used samples of daily data, weekly data and monthly data of yuan-dollar, yuan-yen exchange rate, Shenzhen Composite Index and industrial stock index of Shenzhen stock market for the period 2005/7/21-2008/12/31. The results analyzed by using multi-factor index model are as follows. First, Yuan/Yen and Yuan/Dollar exchange rate has a negative relationship with industry index. This results indicate that industry index rises when exchange rate falls, in another words, industry index rises when the value of Yuan appreciates. Second, Yuan/Yen exchange rate makes more impact on the stock price of industry than Yuan/Dollar exchange rate. Third, The relationship between exchange rate and stock price of industry is found significantly in daily data. When weekly and monthly data are used the relationship between two variable is weakened. Exchange rate of previous period does not affect on stock price of current period. Forth, Exchange rate makes an impact on the stock price of industry which is related with export and import business. Fifth, with using simple regression model between exchange rate and stock index of industry, exchange rate has a negative relationship with stock index of industry overall, however, exchange rate of previous period has a positive relationship with stock index of industry of current period. This thesis investigates how exchange rate make an impact on the stock price of industry in Chinese Schenzhen stock market as economic regime and financial system change.

Developing Improved Strategies of Remediating Arsenic Contaminated Aquifers

Sun, Jing Columbia University 2016 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Groundwater arsenic contamination is currently a global problem, and also a concern at numerous former industrial sites, agricultural sites, landfill sites and mining operations in the U.S. This dissertation aims to develop improved strategies of remediating these arsenic contaminated aquifers. It focuses on two distinct approaches of remediation: (1) mobilizing arsenic from contaminated aquifer sediments to decrease the quantity of arsenic at the source of contamination; and (2) immobilizing arsenic in situ, to decrease the mobility and bioavailability of this arsenic. Optimal remediation may well involve combinations of these two approaches. Arsenic mobilization using oxalic acid is effective because oxalic acid dissolves arsenic host minerals and competes for sorption sites on those minerals. In this dissertation, oxalic acid treatment was tested using sediments with contrasting iron mineralogies and arsenic contents from the Dover Municipal Landfill and the Vineland Chemical Company Superfund sites. Oxalic acid mobilized arsenic from both sites and the residual sediment arsenic was less vulnerable to microbial reduction than before the treatment. Oxalic acid thus could improve the efficiency of widely used pump-and-treat remediation. Oxalic acid did not remove all of the reactive iron(III) minerals in Vineland sediment samples, and thus released significant quantities of arsenic into solution under reducing conditions than the Dover samples. Therefore, the efficacy of pump-and-treat must consider iron mineralogy when evaluating its overall potential for remediating groundwater arsenic. Arsenic immobilization occurs by changing the chemical state, or speciation, of arsenic and other elements in the system. Arsenic is often assumed to be immobile in sulfidic environments. In this dissertation, sulfate reduction was stimulated in sediments from the Vineland Superfund site and the Coeur d'Alene mining district. Sulfate reduction in the Coeur d'Alene sediments was more effective at removing arsenic from solution than the Vineland sediments. The Vineland sediments initially contained abundant reactive ferrihydrite, and underwent extensive sulfur cycling during incubation. As a result, arsenic in the Vineland sediments could not be effectively converted to immobile arsenic-bearing sulfides, but instead a part of the arsenic was probably converted to soluble thioarsenates. Therefore, coupling between the iron and sulfur redox cycles must be fully understood for arsenic immobilization by sulfate reduction to be successful. Arsenic can also be immobilized by retention on magnetite (Fe3O 4). Magnetite is stable under a wide range of aquifer conditions including both oxic and iron(III)-reducing environments. In this dissertation, a series of experiments were performed with sediments from the Dover and Vineland Superfund sites, to examine the potential of magnetite for use in arsenic immobilization. Our data suggest that the formation of magnetite can be achieved by the microbial oxidation of ferrous iron with nitrate. Magnetite can incorporate arsenic into its structure during formation, forming a stable arsenic sink. Magnetite, once formed, can also immobilize arsenic by surface adsorption, and thus serve as a reactive filter when contaminated groundwater migrates through the treatment zone. Reactive transport modeling is used for investigating the magnetite based arsenic immobilization strategy and for scaling laboratory results to field environments. Such modeling suggests that the ratio between iron(II) and nitrate in the injectant regulates the formations of magnetite and ferrihydrite, and thus regulates the long-term evolution of the effectiveness of the strategy. The results from field-scale models favor scenarios that rely on the chromatographic mixing of iron(II) and nitrate after injection. The studies in this dissertation demonstrate that the environmental fate of arsenic depends on the biogeochemical cycling of arsenic, iron, and to a lesser extent, sulfur. The development of effective groundwater arsenic remediation strategies depends on a good understanding of each of the involved processes, and their combinations.

Studies on graph-based coding systems

Sun, Jing The Ohio State University 2004 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

To make full use of the valuable radio spectrum, one of the targets of communications system design is to convey as much information as possible through the spectrum (the channel) allocated for the purpose. For a given channel, the amount of information that can be passed through it is upper bounded by the well-known Shannon channel capacity [40]. The invention of turbo codes in 1993 was a key step in the 50-year effort to design good coding schemes achieving the Shannon capacity. Since then, other coding schemes with similar performance, such as Low Density Parity Check (LDPC) codes [27] and turbo product codes [18] [34], have been re-discovered or invented. The common characteristics of these codes are that they all can be represented by a large (pseudo-)random graph, and iteratively decoded [49]. In this dissertation, we treat three topics in the design and analysis of the two most important graph-based coding schemes: turbo codes and LDPC codes. Together with two component convolutional codes, an interleaver is a key component of a turbo code. We introduce a class of deterministic interleavers for turbo codes based on permutation polynomials over Z N. It is observed that the performance of a turbo code using these permutation polynomial-based interleavers is usually dominated by a subset of input weight 2m error events. Due to the structure of these interleavers, we derive a simple method to find the weight spectrum of those error events. Therefore good permutation polynomials can be searched for a given component code to achieve better performance. LDPC codes can be constructed using an interleaver. In a previous work, the use of maximum length linear congruential sequences (MLLCS) has been proposed for the construction of interleavers for regular LDPC codes with data node degree 3. Since the smallest loop size (girth) is a key characteristic of the graph of the LDPC code, a sufficient condition on the parameters of the MLLCS to generate a graph with girth larger than 4 is given. We extend the sufficient condition to general irregular LDPC codes and also provide sufficient conditions to guarantee even larger girth. It is observed that the error floor of LDPC code (bit error performance at high signal-to-noise ratios) is usually caused by trapping sets, which are sets of data nodes that cannot be corrected by the iterative decoder. We develop an approximated linear system model for the iterative decoding process in a trapping set. Then the probability that the trapping set can be corrected can be estimated by observing the response of the linear system. Using the idea from the analysis of the linear system, the iterative decoder for regular LDPC codes can be slightly modified to greatly decrease the error floor.

Quantitative analysis of deforestation pattern dynamics: Developing forest resilience metrics in an Amazon frontier

Sun, Jing University of Florida 2013 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Deforestation, the process of clearing the Earth's forests, has occurred globally on a massive scale and negatively impacts the resilience of forest landscapes. Aimed to support the understanding of deforestation dynamics, the dissertation first reviews resilience theory, and then demonstrates possible solutions to infer the resilience of deforested landscapes with particular attention to the forest spatial pattern changes via an example in the Amazonian rainforest. The solutions were based on the application of three different methods, and integrating these with remote sensing (RS) and geographic information system (GIS) techniques. Data inputs were fine-grained forest/non-forest classifications of the years 1986, 1991, 1996, 2000, 2005 and 2010 interpreted from Landsat satellite images. The three different methods presented in this dissertation are: first, the combination of a moving window approach and an iterative self-organizing (ISO) unsupervised classification used to describe the 'cross-boundaries' influences of deforestation. These patterns are revealed by forest cover changes, which are initiated from developed areas and then extend into forest areas across multiple spatial scales. Second, the local changes of forest spatial patterns were illustrated, where the dynamics of forest cover were obtained by applying the morphological spatial pattern analysis (MSPA). Two additional MSPA tools, 'hole' and 'outer background', were created to enhance the appreciation of the spatial patterns of developed areas. Third, fractal geometry was introduced to further prompt the understanding of the spatial patterns of developed areas. A fixed-grid scan strategy was adopted to pixelize the entire landscape and to cartographically represent the spatial patterns of developed areas by fractal dimension. Moreover, a configuration framework was proposed to partition the level of deforestation characterized by fractal dimensions and as such can potentially be used to better understand and manage the evolution of forest clearings. These three methods each have their own set of advantages and limitations, and yet work in a complementarily manner and cast particular insight on spatial pattern change during the process of deforestation. Their useful value-added contributions towards resilience theory is discussed at the end, as the ontogenetic stage of resilience theory is moving from the 'consolidating' stage to the 'empirical interactive' stage.

China as mirror: How Japanese national dailies watch China and Japan-China relations, 1972--2004

Sun, Jing The University of Wisconsin - Madison 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

My dissertation, China as Mirror: How Japanese Newspapers Watch China, 1972--2003, examines Japan's top two national dailies' portrayals of China and of Japanese-Chinese relations since the two countries normalized diplomatic relations in 1972. I argue that these portrayals, while politically consequential, are driven more by concerns about Japan than about China, and that journalists are choosing from a series of normative frames, explaining China so as to understand Japan's identity and place in the world. This suggests that China's image has been socially constructed as a mirror by the Japanese media to reflect Japan's major social debates concerning its state purpose, national values, and international role, and revealed how Japanese journalists have been pulled between Japan's Asian and Western identities, forever seeking an internal equilibrium. Methodologically, this dissertation tests all the major claims on media-state relations. First, by using two different newspapers with competing ideological orientations, the study tests whether the Japanese media faithfully carry out the role of being a passive transmitter, and are restrained from going any further beyond being a neutral observer. Second, the study examines the same newspapers across eras. In doing so, it tests the claim that media always criticize the Japanese government, or that they are always supportive of state initiatives. Third, it chooses international coverage to examine the power of national identity in shaping media portrayals, and to demonstrate how portrayals of China have been constructed by media to become relevant to the questions of "who we are" and "what we stand for" among the Japanese public. The goal of this study is to highlight the causal power of norms and ideas. Unlike structurally based approaches that regard identities as causally manipulative to physical realities, this study places identity as an independent variable and shows how "what people believe" shapes the ways journalists interpreted events and determine their unfixed roles vis-a-vis the state and societal actors in a democratic polity.