Diffuse optical tomography: Imaging multiple structural and functional features

Jiang, Ruixin University of Florida 2012 해외박사(DDOD)

Diffuse Optical Tomography has drawn more and more interests in the biomedical field over the recent couple of decades due to its ability to noninvasively recover not only tissue structural information but also functional and molecular properties. The contrasts that optical parameters could demonstrate in DOT are usually higher than those of the conventional methods. Based on these contrasts, different approaches had been developed applying DOT for imaging, and so far lots of efforts were spent on detecting breast cancer by imaging tissue absorption and scattering coefficients as well as hemoglobin concentration and oxygen saturation level. In this work, we tried to expand the ability of DOT in breast cancer detection by introducing Phase-contrast diffuse optical tomography (PCDOT). PCDOT uses near-infrared diffusing light to non-invasively reconstruct tissue refractive index (RI) distribution. RI depends on the tissue’s physical and chemical properties and previous study revealed that it might serve as a promising imaging parameter in breast cancer detection. We’ve first developed a 2-step method to improve the PCDOT image both qualitatively and quantitatively at single-wavelength; then we’ve introduced a multispectral PCDOT algorithm to more efficiently reconstruct RI simultaneously with other tissue functional parameters and attempted to improve this algorithm by different structural regularization methods. Measuring hemodynamic changes, oxygen delivery and cerebral blood flow is important for locating and interpreting pathological variations associated with epileptic disorders. We then further expanded the application of DOT by presenting a method of dynamic, noninvasive and functional diffuse optical brain imaging that is conducted simultaneously with hippocampus CA1 local field potential recordings for anesthetized rats under resting conditions and during acute chemoconvulant provoked seizures. By illuminating the scalp with near-infrared light and recovering, the backward scattered light were collected and three-dimensional (3D) absolute tissue optical absorption images with high temporal resolution were obtained using a finite-element based reconstruction algorithm. The measured tissue absorption changes were validated with optic-intrinsic-signals measurement. In the focal seizure model, the seizure focus could be identified using the technique denoted by local variations of tissue absorption level as well as hemoglobin and cerebral blood flow changes. The findings are consistent with general observations in seizures of significant local cerebral metabolism increase. Successive absorption images along with EEG signals demonstrated linearity relationships from the neurovascular coupling study, suggesting cerebral metabolism closely matches demand from neuronal changes. This preclinical study suggests that this technique is feasible to be applied to human study and can provide insights into brain function and mechanisms of seizure disorders.

Computational and Physical Quality Assurance Tools for Radiotherapy

Graves, Yan Jiang University of California, San Diego 2013 해외박사(DDOD)

Radiation therapy aims at delivering a prescribed amount of radiation dose to cancerous targets while sparing dose to normal organs. Treatment planning and delivery in modern radiotherapy are highly complex. To ensure the accuracy of the delivered dose to a patient, a quality assurance (QA) procedure is needed before the actual treatment delivery. This dissertation aims at developing computational and physical tools to facilitate the QA process. In Chapter 2, we have developed a fast and accurate computational QA tool using a graphics processing unit based Monte Carlo (MC) dose engine. This QA tool aims at identifying any errors in the treatment planning stage and machine delivery process by comparing three dose distributions: planned dose computed by a treatment planning system, planned dose and delivered dose reconstructed using the MC method. Within this tool, several modules have been built. (1) A denoising algorithm to smooth the MC calculated dose. We have also investigated the effects of statistical uncertainty in MC simulations on a commonly used dose comparison metric. (2) A linear accelerator source model with a semi-automatic commissioning process. (3) A fluence generation module. With all these modules, a web application for this QA tool with a user friendly interface has been developed to provide users with easy access to our tool, facilitating its clinical utilizations. Even after an initial treatment plan fulfills the QA requirements, a patient may experience inter-fractional anatomy variations, which compromise the initial plan optimality. To resolve this issue, adaptive radiotherapy (ART) has been proposed, where treatment plan is redesigned based on most recent patient anatomy. In Chapter 3, we have constructed a physical deformable head and neck (HN) phantom with in-vivo dosimetry capability. This phantom resembles HN patient geometry and simulates tumor shrinkage with a high level of realism. The ground truth deformation field can be measured from built-in surface markers, which is then used to verify the accuracy of an important ART step of deformable image registration. Our experiments also demonstrate the feasibility of using this phantom as an end-to-end ART QA phantom with an emphasis on testing the dose deliver accuracy.

Two Parameter Inference Methods in Likelihood-Free Models: Approximate Bayesian Computation and Contrastive Divergence

Jiang, Bai ProQuest Dissertations & Theses Stanford Universit 2016 해외박사(DDOD)

This dissertation is a summary of my three major projects in my PhD program.A version of Chapter 2 has been accepted by Statistica Sinica [Bai Jiang, Tung-Yu Wu, Charles Zheng, and Wing Hung Wong. Learning summary statistic for Approximate Bayesian Computation via deep neural network. arXiv preprint arXiv:1510.02175. 2015]. I was the first author, responsible for all major areas of concept formation, methodology, mathematical proof, experiments, data analysis, as well as the majority of manuscript composition. Wu T-Y contributed to conducting simulation experiments, and Zheng C contributed to manuscript composition and proofreading the mathematical texts in the proof. Wong WH was the supervisory author on this project and was involved throughout the project.A version of Chapter 3 has been submitted to one of the top journals in Statistics and is now available in arXiv, a repository of electronic preprints, [Tung-Yu Wu, Bai Jiang, Yifan Jin, Wing Hung Wong. Convergence of Contrastive Divergence algorithm in exponential family. arXiv preprint arXiv:1603.05729. 2016]. Wu T-Y and I were co-first authors contributing equally to this project. Wu T-Y was involved in the early stages of concept formation and conducted preliminary experiments. I was responsible for mathematical proof, experiments, data analysis and manuscript composition. Jin Y was involved in the early stages of concept formation and contributed to mathematical proof. Wong WH was the supervisory author on this project and was involved throughout the project.A version of Chapter 4 has been submitted to one of the top journals in Statistics and is now available in arXiv [Bai Jiang, Tung-Yu Wu, Wing Hung Wong. Convergence of Contrastive Divergence with annealed learning rate in exponential family.arXiv preprint arXiv:1603.06220. 2016]. I was the first author, responsible for all major areas of concept formation, mathematical proof, experiments, data analysis and manuscript composition. Wu T-Y was involved in the early stage of concept formation. Wong WH was the supervisory author on this project and was involved throughout the project.

Understanding mechanical environment changes and biological responses to canine retraction using T-loop

Jiang, Feifei Purdue University 2015 해외박사(DDOD)

Jiang, Feifei. Ph.D., Purdue University, May 2015. Understanding Mechanical Environment Changes and Biological Responses to Canine Retraction Using T-loop. Major Professors: Jie Chen, School of Engineering and Technology, Anil Bajaj, School of Mechanical Engineering. Predictability of tooth displacement in response to specific orthodontic load system directly links to the quality and effectiveness of the treatment. The key questions are how the tooth's environment changes in response to the orthodontic load and how the biological tissues respond clinically. The objectives of this study are to determine the mechanical environment (ME) changes and to quantify the biological tissues' response. Eighteen (18) patients who needed maxillary bilateral canine retractions were involved in the study. A method was developed to quantify the 3D load systems on the canine, which allowed the treatment strategies to be customized in terms of orthodontic loading systems to meet either translation (TR) or controlled tipping (CT) requirement. Dental casts were made before and after each treatment interval, and the Cone Beam Computed Tomography (CBCT) scans were taken prior to and following the entire treatment for control of treatment strategy and post treatment evaluations. Finite element method (FEM) was applied to calculate the location of center of resistance (CRes) for tooth movement control. The location and variation of CRes were recorded and compared with previous studies. A quick CRes assessment method that locates CRes by calculating the centroid of the contact surface (CCS) and the centroid of the projection of root surface (CPCS) in certain direction was also tested and compared with the results from FEM. Customized T-loop spring, a kind of orthodontic appliance, was designed, fabricated, and calibrated on a load measuring system to ensure that the load met the clinician's prescription. The treatment outcomes in terms of tooth displacement and root resorption characterized by the changes of tooth length and volume as well as the bone mineral density (BMD) represented by the Hounsfield units (HU) change were recorded and analyzed. The ME in terms of stress were also calculated by using FEM. Paired t-test and mixed model ANOVA methods were used to analyze the relationships between the mechanical inputs (quantified and customized load, and corresponding stress) and clinical outcomes (root resorption and BMD change). It was found that the overall root resorption is not significant for canine retraction, but apical root resorption does occur, meaning that orthodontic load is not a sufficient factor. Also, it was observed that HU distribution changed significantly in both root and alveolar bone. The maximum reduction was on the coronal level in the direction perpendicular to the direction of movement in root, and in the direction of the tooth movement at the coronal level in bone. In addition, it was determined that the locations of the CRes in the MD and BL directions were significantly different. The locations of the CRes of a human canine in MD and BL directions can be estimated by finding the CPCSs in the two directions. Finally, it was shown that the stress invariants can be used to characterize how the osteocytes feel when ME changes. The stress invariants in the alveolar bone are not significantly affected by different M/F. The higher bone modeling/remodeling activities along the direction of tooth movement may be related to the initial volumetric increase and decrease in the alveolar bone.

Raman spectroscopy of single molecules on noble metal nanoparticles

Jiang, Jiang Columbia University 2003 해외박사(DDOD)

This thesis presents theoretical calculations and experimental results on the mechanism of surface enhanced single molecule Raman spectroscopy. Raman scattering from single Rhodamine 6G molecule adsorbed large Ag nanoparticles was studied. A superlinear power dependence of the SERS signal was observed. The result is discussed in terms of model where single R6G molecule that yields surface enhanced Raman signal is located at the junction of two Ag nanoparticles. By increasing the incident light intensity, the huge gradient force can pull the molecule further into the junction. The dynamics of molecular motion and junction geometry were investigated by Raman depolarization studies. Results show depolarization ratio is wavelength independent for both the R6G Raman lines and the underlying continuum. In addition, depolarization ratio can usually be changed by changing the laser polarization on the sample, and varies as a radiating dipole of extreme anisotropic Raman tensor. This is explained by the local field properties at the junction sites of particle aggregates. The origin of the Raman continuum is proposed as the Ag electronic Raman triggered by chemisorbed R6G. Classical electromagnetic (EM) field calculations are presented to discuss the EM field enhancement for a single sphere and dimer of spheres as a function of separation. For a Ag particle dimer, as separation gets smaller, the EM field at the junction is further enhanced at least 4–6 orders of magnitude compared to the single sphere case. The density distribution of coherent oscillating electron-hole pairs in the sphere is also calculated as a function of particle distance. It changes from a volume excitation in an isolated sphere to a surface excitation in a closely spaced dimer. Controlled metal nanoparticle dimers have been self-assembled using rigid conjugated di-thiol bridging molecules. Preliminary results show that weak Raman signal from single optically transparent molecule at particle junctions is observed.

한국 문화에 대한 친숙도가 한국 전통춤 인식에 미치는 영향 : 중국 유학생을 중심으로

JIANG CHAO 한세대학교 대학원 2020 국내석사

본 연구의 목적은 수도권 중국유학생들이 한국문화에 대한 친숙도가 한국 전통춤에 대한 인식 및 태도에 대해 어떤 영향을 미치는 알아보고자 함에 있다. 이를 위해 수도권에서 재학중인 중국 유학생을 대상으로 설문조사 하였다. 회수한 설문지를 토대로 SPSS 21.0을 이용하여 통계 처리하였다. 연구 결과는 다음과 같다. 첫째, 연구가설1의 검증결과에서 수도권 재한 중국유학생의 개인적 변인은 한국 전통춤에 대한 인식과 태도에 모두 영향을 미치고 있었다. 독립변인별로 인식에서는 한국어 체험학습이, 태도에서는 한국유학기간이 가장 큰 영향을 미치고 있음을 보여 주었다. 둘째, 연구가설2의 검증결과에서 수도권 재한 중국유학생의 한국문화에 대한 지각된 친숙도가 한국 전통춤에 대한 인식과 태도에 모두 영향을 미치고 있었다. 독립변인별로 인식에는 한국문화에 대한 인식과 태도 모두 한국 문화에 대한 선호도가 가장 큰 영향을 미치고 있음을 보여주었다. 이상의 결과들은 다음의 의미들을 함의한다. 첫째, 중국유학생들이 한국 문화에 대한 관심이 전통춤에도 연결되고 있다. 한국 문화가 한류라는 이름으로 전 세계에 소개되는 가운데, 중국의 젊은 세대들은 더욱 관심을 갖고 있으며 한국으로 유학까지 오게 하는 동기를 제공하고 있다. 미래 중한관계도 이들이 가교 역할을 할 수 있다는 긍정적인 관점에 더욱 발전할 수 있을 것이다. 둘째, 한국의 유학기간이 긴 중국학생들은 한국어로서 다양한 문화적인 체험학습을 했을 것이다. 따라서 한국 전통춤에 대한 인식이나 태도에 있어 우호적이며 긍정적인 역할을 하게 했을 것이다. 특히 중국 문화와 비교하고자 하는 탐구심과 지금 알려지고 있는 한국의 현대 문화와는 달리 전통춤의 경우 한국의 전통적인 측면을 간직하고 있어 더욱 관심을 갖게 되었던 것이다. 셋째, 전통춤 속에서의 민족성을 대표한다는 점은 양국 국민간의 공감할 수 있는 부분이다. 이러한 공감대 형성은 문화교류를 통해 보다 자세하게 소개된다면, 공감대 및 공동인식을 빠르게 형성하게 하여 더욱더 관심을 증가하게 하면서 문화교류가 보다 확대하게 할 것이다.

한국의 기술혁신체계와 기술추격에 대한 연구 : 1980-90년대 반도체산업을 중심으로

Jiang Ming Xu 인제대학교 2011 국내석사

Study on Korea’s Technological Catch-up Based on NIS Focusing on Korea’s Semiconductor Industry in 1980-1990s Jiang Mingxu (Advisor : prof. Park Seok Keun, E, D) Department of International Trade Graduate School, Inje University Catch-up is a very important phenomenon in the world economy. Gershenkron argues that targeting rapidly growing and advanced technologies is the advantage of catching-up countries. From national innovation system approach, technological innovation are central to the catching-up process, and a country(or firm) must be able to use a specific “window of opportunity” to realize catch-up if they implement appropriate social, industrial and technology policies, here is NIS; otherwise, it will continue to lag behind. Many countries and economies have successfully exploited their window of opportunity, such as the USA in the 19th century, Japan from the 1960s, later Korea, Taiwan and Singapore. Korea, the new industrialized country emerging in East Asia, just through these kinds of catching up process, achieved the “Han River Miracle”(漢江奇蹟) in the relatively short time in last century and now have been one of the economic powers of the world especially in the field of electric industry, auto motor, semiconductor industry, shipbuilding and so on. But the catching up road also has the Korean characteristics so the paper here will explore and analyze the Korea’s catching up road on case of semiconductor industry, which is regarded as today and tomorrow’s “ industry of industries”, to explain the Korea’s success. Korea were first able to enter the semiconductor market in the early 1980s and produced less than one per cent of world semiconductor output in the mid-1980s; but emerged as significant semiconductor producer in the late 1980s/ 1990s and rapidly had overtaken Europe in output terms, and by the 1990s it became the world’s third largest semiconductor producer, next only to the United States and Japan, with about 10 per cent of the world total share and the world-class semiconductor producer: Samsung and Hyundai. This success of Korea’s semiconductor industry has been the typical case for the developing countries and especially for Korea’s neighbor-China. Therefore, as a new economy with the rapid developing rate, China should learn from Korea’s valuable experience of NIS and create its own window of opportunity to realize technological catching up at the field of semiconductor. Key words: technological catch- up, national innovation system, semiconductor industry 국문 초록 한국의 기술혁신체계와 기술추격에 대한 연구 : 1980-90년대 반도체산업을 중심으로 장명욱 (지도교수: 박석근) 인제대학교 대학원 국제통상학과 경제적 후발국가가 선진국을 추격하는 것은 세계경제의 중요한 현상이고 주요 연구과제다. 게르센크론에 의하면 후발국가는 주로 선진국의 급속히 성장하는 선진기술을 모방과 흡수의 목표로 삼고 추격을 하게 된다. 이와 함께 적절한 기술정책, 산업정책 및 사회정책 등을 포괄적으로 수행할 때 그 후발국가는 소위 도약을 위한 ‘기회의 창’을 활용할 수 있게 되고 결국은 추격에 성공을 하고 선진산업국의 대열에 진입을 하게 된다. 이것은 19세기 미국, 20세기 일본, 나아가 20세기 말 한국과 싱가폴 등의 경험에서 확인할 수 있다. ‘한강의 기적’을 통해 신흥공업국에서 전자, 자동차, 조선 및 반도체 등의 산업에서 강력한 경쟁력을 확보하는데 성공한 한국은 기술후발국에 의해 이뤄진 ‘추격’의 전형적인 사례다. 그러나 한국의 추격에는 후발국의 추격과정이 갖는 보편적인 내용 뿐만 아니라 한국 고유의 특수성이 확인된다. 이것을 본 연구에서는 한국의 국가혁신체계라는 틀 속에서 규명하고자 하였다. 연구의 대상산업은 반도체로 하였고, 시대는 1980-1990년대로 하였다. 반도체는 이 시대에 ‘산업 중의 산업’이다. 시기를 1980-90년대로 국한한 것은 한국의 국가혁신체계가 국가주도에서 재벌주도로 극적으로 변화하는 시기였고 그 경향을 반도체산업을 통해 가장 잘 확인할 수 있기 때문이다. 반도체를 중심으로 한국이 세계적인 산업대국으로 부상하는데 성공하는 데에는 순조로운 세계경제적 환경뿐만 아니라 정교하고도 역동적인 한국만의 고유한 국가혁신체계가 작동하였기에 가능한 것이었다. 여기에는 한국의 정부, 재벌 및 대학 및 연구기관의 조화로운 역할과 이를 아우르는 다양한 정책들이 포괄된다. 이러한 한국의 성공사례는 반도체 등의 산업에서 새로운 도약을 준비하고 있는 중국의 추격에 매우 유익한 타산지석의 교훈이 될 수 있다. 아직 전통적인 국가 주도적 국가혁신체계에서 벗어나지 못하고 있는 중국이 반도체를 비롯한 미래지향적 산업에서 추격을 이뤄내고 선진산업국가로 진입하기 위해서는 한국과 같이 유연하고 역동적인 국가혁신체계를 구축하여야 할 것이고 이에 대한 많은 연구가 있어야 할 것이다. 핵심단어: 기술추격, 국가혁신체계, 반도체산업

중국인 한국어 학습자의 추측 양태 표현 습득 연구 : '-겠-', '-(으)ㄹ 것이다', '-(으)ㄴ가/나 보다'를 중심으로

JIANG, CHUAN 이화여자대학교 국제대학원 2015 국내석사

The aim of this study is to investigate the supposed modality expressions, ‘-겠-’, ‘-(으)ㄹ 것이다’, ‘- (으)ㄴ가/나 보다’ of Chinese Korean learners. Modality exists cross-linguistically, but it is not the same as every language. Korean speculative expressions are especially diversified. Those who has similar meaning holds delicate semantic differences, so it is not easy to distinguish them. Such a semantic difference causes varied pragmatic function in the discourse, so it is very important for them to acquire semantic differences of speculative expressions. It is essential to make a contrast analysis about the Korean performance of the modal point system and its corresponding Chinese morphophonemic auxiliary verb in contrast to the grammar, in order to make the Chinese who are learning Korean language to use modal performances appropriately and correctly. The composition of this study is as the followings below: In Chapter Ⅰ, this study identifies necessity and aim of the study, reviews studies on speculative expressions in teaching Korean as a foreign language and presents research topics. In Chapter Ⅱ, it examined speculative expressions as the sub-category of epistemic modality and selected expressions for discussions. It had also examined the presence of syntactic and semantic characteristics, and the corresponding of the Chinese supposed modality expression. In Chapter Ⅲ, it explains participants for research, study procedures, test items for inspecting use of speculative expressions in the study, and the analytic methods of the collected data. In Chapter Ⅳ, it describes the research results. Firstly, as a results of comparing Korean native speakers to Chinese Korean learners, there is a difference in the use of speculative expression. The average mark of Chinese Korean learners is lower than the native Koreans. This proofed that the acquisition of Chinese Korean learners was not completely full. Secondly, as the result of inspecting use modality by proficiency according to their native language, there was a significant difference in the lower ranked learners and higher ranked learners in general. It does not have a good acquisition between the lower ranked learners and higher ranked learners due to the effect of native language. Finally in Chapter Ⅴ, it identifies research results and presents its significance and limitation. This study has significance as the foundation for the future speculative expression instruction in the educational fields in that it examined firstly speculative expressions centered on learners, and secondly their acquisition modality of expressions. However, it depends whether learners acquired difference of pragmatic function according to the meaning of speculative expressions. Therefore, complementary studies are required hereafter. 본 연구의 목적은 중국인 한국어 학습자의 한국어 추측 양태 표현 ‘-겠-’, ‘-(으)ㄹ 것이다’, ‘-(으)ㄴ가/나 보다’의 습득 양상을 고찰하는 것이다. 한국어에서 추측 양태 표현은 다른 양태 표현에 비해 다양하게 존재하고 통사적인 제약에 따라 의미 차이가 있으며 상황에 따라 의미 특성이 다르다. 따라서 학습자들은 이 표현들이 혼동될 수밖에 없으며, 정확하게 구별해서 사용하기가 어렵다. 동시에 추측 양태 표현은 중국어에도 있지만 두 언어 간의 차이 때문에 중국인 학습자가 한국어 추측 양태 표현을 배울 때 많은 어려움을 가진다. 제2언어 교육에서 학습자의 모국어 영향은 꾸준히 강조되어 왔으며 한국어 교육에서 중국인을 대상으로 한 추측 양태 표현의 습득 연구가 있지만 대응하는 중국어 표현을 같이 살펴보는 연구는 없었다. 또한 본고의 조사 대상인 중국인 학습자는 현재 한국 내 한국어 학습자 중 가장 많은 수를 차지하고 있어 중국인 학습자를 대상으로 한 습득 연구는 실제 한국어 교수 현장에 상당한 도움이 될 것이라 판단하였다. 이를 위해 한국어에서 사용 빈도가 높고, 한국어 교육 현장에서도 비중 있게 제시되고 있는 추측 양태 표현 ‘-겠-’, ‘-(으)ㄹ 것이다’, ‘-(으)ㄴ가/나 보다’를 논의의 대상으로 선정하여 각 추측 양태 표현이 사용되는 통사적, 의미적 특성을 바탕으로 추측 양태 표현 평가지를 제작하여 실험조사를 실시하였다. 각각의 결과는 중국인과 한국어 모어 화자, 또는 숙달도에 따라 분류한 중국인 상집단과 하집단의 비교를 통해 집단 간의 습득 양상이 어떠한 차이가 있는지를 살펴보았다. 본고의 구성은 다음과 같다. Ⅰ장에서는 연구의 필요성 및 목적을 밝히고 선행연구에 대해 검토하여 연구 문제를 설정하였다. Ⅱ장에서는 논의의 대상이 되는 추측 양태 표현을 선정하고 그 통사적, 의미적 특성을 살펴보았다. 통사적 특성은 주어 인칭과 용언 제약, 문장 종결법 제약, 과거 시제 형태소의 결합 제약으로 분류하여 살펴보았고 의미적 특성은 판단의 근거와 확실성의 정도로 구분해서 살펴보았다. 마지막으로 선정된 추측 양태 표현에 대응하는 중국어 표현을 살펴보았다. Ⅲ장에서는 연구 대상인 실험 참여자와 실험 도구를 밝히고 수집한 자료를 분석하는 방법과 연구 절차를 설명하였다. Ⅳ장에서는 연구 결과를 기술하였다. 자료 분석 결과, 첫째, 중국인 한국어 학습자의 추측 양태 표현 사용 양상은 통사적, 의미적 특성에 관련하여 모두 한국어 모어 화자와 차이가 있었다. 중국인 학습자가 한국어 모어 화자보다 전체적으로 낮은 평균 점수를 나타내며 학습자가 추측 양태 표현을 완전히 습득하지 못하였음을 보여주었다. 둘째, 숙달도에 따른 중국인 상집단과 하집단 추측 양태 표현 사용 양상에 차이가 있었다. 통사적, 의미적 특성과 관련한 중국인 학습자 상, 하집단의 유의미적인 차이는 논리적 추론에서만 확인되었다. 의문문 제약과 관련하여 숙달도에 상관없이 잘 습득하지 못하였음을 확인하였는데 그 이유는 모국어의 영향으로 설명할 수 있다. 나머지 제약에서는 숙달도 변인이 작용하여 숙달도가 높아질수록 더 잘 습득하는 경향이 있음을 확인하였다. 마지막으로 본 연구의 의의와 한계를 밝히면 다음과 같다. 그간의 추측 양태 표현에 대한 연구는 주로 교수자 입장에서 이루어졌으나, 본 연구는 학습자 중심으로 추측 양태 표현에 대해 살펴보았다는 점에서 의의가 있다. 또한 학습자의 추측 양태 표현 습득 양상에 대해 살펴봄으로써 학습자에게 어떤 추측 양태 표현이 어려운지 알 수 있었는데, 이는 향후 교육 현장에서 추측 양태 표현 교수를 위한 밑거름이 될 것이라는 점에서 의미를 가진다. 또한 본고는 중국어의 추측 양태 표현을 같이 살펴보고 학습자 추측 양태 표현의 사용 양상을 설명하였다는 점에서 의미를 지닌다. 그러나 본 연구는 중국인 한국어 학습자의 추측 양태 표현 습득 양상을 통사적, 의미적 특성에 한정하여 살펴본 것으로, 담화상의 화용적 기능에 대해서는 살펴보지 않은 것에 한계가 있다. 따라서 앞으로 추측 양태 표현의 화용적 기능에 대한 학습자의 습득 연구도 진행되기를 기대한다.

Effect of Y-box Binding Protein 1 and 2 on Early Porcine Embryonic Development

Jiang, Wenjie 충북대학교 2023 국내박사

Y-box binding protein 1 and 2 (YBX1, 2) is a member of the family of DNA- and RNA-binding proteins that play crucial roles in multiple aspects, including RNA stabilization, translational repression, and transcriptional regulation; however, its roles in embryo development remain less known. To investigate the function of YBX1 and its mechanism of action in porcine embryo development, YBX1 was knocked down by microinjecting YBX1 siRNA at the one-cell stage. YBX1 was located in the cytoplasm during embryonic development. The mRNA level of YBX1 was increased from the four-cell stage to the blastocyst stage but was significantly decreased in YBX1 knockdown embryos compared with the control. Moreover, the percentage of blastocysts was decreased following YBX1 knockdown compared with the control. Defecting YBX1 expression increased maternal gene mRNA expression and decreased zygotic genome activation (ZGA) gene mRNA expression and histone modification owing to decreased levels of N6-methyladenosine (m6A) writer N6-adenosine-methyltransferase 70 kDa subunit (METTL3) and reader insulin-like growth factor 2 mRNA binding protein (IGF2BP1). In addition, IGF2BP1 knockdown showed that YBX1 regulated the ZGA process through m6A modification. In conclusion, YBX1 is essential for early embryo development because it regulates the ZGA process. In addition, YBX1 regulates mRNA stability of PINK1 and PRKN to affect mitophagy. To study the function of YBX1 on mitochondria in porcine embryo development, YBX1 was knocked down via siRNA microinjection in the one-cell stage. The blastocysts were lower in the YBX1-knockdown group than that in the control group. Notably, knockdown of YBX1 decreased the PINK1 and PRKN mRNA levels. YBX1 knockdown resulted in decreased levels of PINK1, PRKN, activated mitochondria and SIRT1, indicating reduced mitophagy and mitochondrial biogenesis. Furthermore, YBX1 knockdown increased GRP78 and calnexin levels, led to endoplasmic reticulum stress. Additionally, YBX1 knockdown increased autophagy and apoptosis. In conclusion, knockdown of YBX1 decreased mitochondrial function, increased ER stress as well as autophagy during embryonic development. To explore the function of YBX2 in early porcine embryonic development, YBX2 was knocked down by siRNA microinjection in the one-cell stage. The results showed that YBX2 is localized in the nucleus and cytoplasm during the two- and four-cell stage and in the cytoplasm at the blastocyst stage. Knocking down YBX2 decreased the blastocyst rate. Knockdown of YBX2 decreased mitochondrial activity, NRF1, NRF2, SIRT1 and PGC1α levels, thereby reducing mitochondrial function. In addition, knockdown of YBX2 increased maternal gene mRNA levels and decreased ZGA gene mRNA levels. However, the maternal gene protein levels were reduced, indicating that YBX2 can affect maternal to zygotic transition. Meanwhile, H3K9ac level was decreased and H3K9me3 level was increased following YBX2 knockdown, suggesting that YBX2 regulated genes transcription. In conclusion, YBX2 affects embryonic development by regulating ZGA. Taken together, knockdown of YBX1 impairs ZGA process and mitochondrial biogenesis, induces ER stress, autophagy as well as apoptosis. Knockdown of YBX2 disrupts mitochondrial function and ZGA process. Therefore, YBX1 and YBX2 play a crucial role in early porcine embryonic development by regulating ZGA process.

The Development of Charles Dickens’ Views on Victorian Gentleman: Oliver Twist, David Copperfield, and Great Expectations

Jiang Jindi 강원대학교 일반대학원 2017 국내박사

As three representative works of Dickens in his early, middle, and later writing periods, Oliver Twist, David Copperfield, and Great Expectations offer a comprehensive reflection of people’s moral outlook and English society in the Victorian Age. This dissertation aims to explore the development of Dickens’ views on Victorian gentleman. The introductory part of this dissertation offers a brief survey of Dickens’ life and works, and gives a critical glimpse of the past criticisms. Dickens’ literary creation is closely related to his legendary personal experiences. Based on his experiences, Dickens’ autobiographical novels can be categorized into three stages: rosy optimism in Oliver Twist, anxiety in David Copperfield, and moral enlightenment in Great Expectations. Chapter II introduces the background and definition of the Victorian concept of gentleman in the nineteenth century. Chapter III demonstrates Dickens’ optimistic view of Victorian gentleman in his early writing career by analyzing Oliver Twist. As a young man, Dickens simply regarded life as a struggle between good and evil, and believed that evil was just an individual phenomenon, which must be conquered in the end by good. This chapter treats Oliver’s unique orphan image and his distinguished humanity as the hero of the novel. Oliver is born and fostered in a brutal and inhumane workhouse and receives neither proper education nor any rightful moral guidance from anyone near him. However, he stays pure despite being in the midst of the ugliest thieves’ den. Many other perfect characters are likewise present in the novel, and such characters tend to represent various ideal moral concepts. Oliver Twist presents how Oliver is able to defeat misfortune, evil and temptation by virtue of fate. In conclusion, Oliver Twist reflects the writer’s intention to improve people’s life and social conditions. However, it may be pointed out that his hyperoptimistic view of life degrades the literary value of Oliver Twist. Chapter IV discusses Dickens’ awareness of reality and anxiety in his conception on Victorian gentleman in David Copperfield in his middle stage. Dickens takes notice of further dark and serious sides in his middle writing period. A group of novels in the middle period embody Dickens’ penetrating insight into Victorian society and gentleman of the mid-19th century. Dickens’ insight portrays a part of his inner contradictions and confusion about Victorian gentleman. As a result, the tone of the novels in Dickens’ middle period is rather serious. The most autobiographical novel becomes the best place for Dickens to make an outpouring of his variety of emotions, especially his struggles and conflicts. Disclosing the duplicity seen in David, Dora, and Agnes and other characters and the illusions they create, Dickens reveals further his anxiety of gentleman and social reality. Chapter V goes further to look into the last stage of Dickens’ development in his view on Victorian gentleman. In the latter stage, Dickens encounters personal misfortunes in life and marriage. In addition, he comes to develop a deeper and thorough understanding of the basic contradictions of Victorian England and humanity. Great Expectations, which represents the summit of Dickens’ intellectual maturity, is one of his most brilliant novels with a writing style of lucid diction and deep thought in his latter stage. Although the good heroes appear in a closing part of Great Expectations, such an ending happens only after the cost of overcoming many hardships and heavy loss. Dickens’ mature insight into Victorian gentleman and his moral growth can be easily detected in Great Expectations. The concluding part gives both a general and detailed comparison of the similarities and differences between Dickens’ three major novels and focuses on the process of Dickens’ developing views on Victorian gentleman.