Van der Waals epitaxy and beyond for monolithic 3D integration

As the limitations of silicon-based technologies approach their physical boundaries, monolithic three-dimensional integration (M3D) and two-dimensional (2D) materials, such as transition metal dichalcogenides (TMDs), have emerged as promising solutions for continuous scaling in semiconductor devices. This perspective explores the evolution of van der Waals (vdW) epitaxy and its potential to integrate TMDs into M3D structures. By circumventing lattice mismatch issues, vdW epitaxy allows the formation of high-quality single-crystal heterostructures across diverse material systems. However, the challenge of achieving films with uniform thickness control remains unresolved. Herein, advanced epitaxial growth techniques for TMDs are reviewed, including quasi-vdW epitaxy, vdW recrystallization, and remote epitaxy, whilst also introducing emerging approaches, such as hypotaxy and interfacial epitaxy. These emerging techniques have the potential to produce large-area defect-free films with controllable thicknesses. Ultimately, the development of new epitaxial methods specifically designed for TMDs is essential for the future integration of 2D materials into industrial applications.N

Languaging in Second-Language Acquisition: Review of Its Cognitive and Affective Roles in L2 Learning

This paper reviews languaging in SLA, with emphasis on its cognitive and affective roles in L2 learning. Based on Vygotskys Sociocultural Theory and Swains concept of languaging, this study examines the contribution of spoken and written languaging to L2 grammar acquisition, writing development, and learner motivation. Research suggests that languaging enhances metalinguistic awareness, thus helping learners analyze and refine their language use. Additionally, self-directed and collaborative languaging facilitate deeper cognitive engagement and self-regulation in learning. Studies pertaining to motivational languaging indicate that expressing language-learning goals in writing strengthens motivation and commitment to L2 learning. However, existing research focuses primarily on short-term effects, whereas the effects of individual differences, task design, and long-term engagement on the effectiveness of languaging are not sufficiently analyzed. This paper synthesizes the key findings, discusses the methodological limitations, and highlights the necessity for further investigating the effects of instructional scaffolding and learner characteristics on the sustained benefits of L2 languaging

First- and Second-Person Pronoun Use by East Asian EFL Learners: Corpus-Based Study of Argumentative Essays

Based on the ICNALE corpus, this study investigates the use of first- and second-person pronouns in argumentative essays by Chinese, Korean, and Japanese leaners of English as a foreign language (EFL) across four proficiency levels. The findings indicate that higher-proficiency learners use these pronouns less frequently, which aligns with prior studies on Western EFL learners. Additionally, Korean and Japanese learners show stronger preference for I over we, whereas Chinese learners exhibit the opposite pattern. These differences may stem from various factors, such as cultural influences or first-language (L1) rhetorical conventions. Statistical analyses suggest that L1 background exerts a stronger effect on pronoun usage than proficiency level. This challenges the prescriptive English for Academic Purposes guidelines, which discourage first-person pronouns for novice writers regardless of their linguistic background. Meanwhile, pedagogical approaches that emphasize the rhetorical functions of pronouns may better equip learners in making informed lexical choices based on their communicative intent

고분자 유체의 고체-액체 계면에서의 분자층 형성에 대한 유변학적 연구

학위논문(박사) -- 서울대학교 대학원 : 자연과학대학 물리·천문학부(물리학전공), 2025. 2. 제원호.유체의 유변학적 특성은 일상생활에서 경험하는 파괴, 마찰, 젖음과 같은 기계적 현상을 설명한다. 과학과 기술의 발전과 함께, 더 작은 규모에서 물리적 특성을 이해하는 것이 점점 중요해지고 있다. 그러나 크기가 유사하고 연속족 모델이 더 이상 유효하지 않은 나노스케일에서는 이러한 이해가 여전히 도전 과제로 남아있다. 이에 따라 나노와 벌크 스케일 사이의 유변 모듈러스를 연속적으로 이해하기 위해 우리는 멀티스케일 레올로지를 성공적으로 수행할 수 있는 수정 진동자 기반-원자힘 현미경 (QTF-AFM) 기반 레오미터를 제시한다. 또한, 우리는 고분자 유체가 나노스케일 계면에서 비정질 상태에서 층상 구조로 구조적 전이를 할 수 있음을 관찰했다. 다양한 고체 표면에서 고분자 유체의 구조를 실험적으로 시각화하고 복소 모듈러스를 정량화했다. 인력 상호작용하는 표면에서 고분자의 분자량이 증가함에 따라 층상 구조가 강화되다가 얽힘이 발생하면 얽힘으로 인한 분자 간 상관관계로 인해 층상 구조가 억제되는 것을 발견했다. 더불어, 층상 구조는 손실 모듈러스 (loss modulus)를 현저히 감소시키는 동시에, 표면과의 거리에 대해 진동하는 저장 모듈러스 (storage modulus)를 나타낸다. 결과적으로, 층상 계면 유체에서는 거리의 변화에 따라 고체적 성질과 유체적 성질이 번갈아 나타나는 특성이 관찰된다. 이러한 고체와 유체상의 공존은 계면에서의 유체의 구조와 물성 관계에 대한 오랜 질문에 대한 실마리를 제공한다. 우리의 연구 결과는 나노스케일부터 벌크스케일까지 복잡한 유체의 마찰-유변학적 (tribo-rheology) 특성을 종합적으로 이해할 수 있는 기초를 제공한다.The rheological characteristics of fluids describe mechanical phenomena encountered in daily life, such as fracture, friction, and wetting. With advancements in science and technology, understanding physical properties at smaller scales has become increasingly important. However, this remains challenging, as the continuum description applicable at the bulk- and micro- does not hold at the nanoscale, where structures are comparable in size and the continuum model for fluids breaks down. Therefore, to bridge the gap between nano- and bulk-scale rheological moduli, we present a quartz tuning fork-atomic force microscope (QTF-AFM) based rheometer for successfully performing multiscale rheology. Also, we observe that polymeric fluids can undergo a structural transition from the amorphous to the layered state at nanoscale interfaces. We experimentally visualize the structure and quantify the complex modulus of polymeric fluids on various solid substrates. We find that the layering enhances with increasing molecular weight of the polymer on attractive surfaces until entanglement occurs. Once entanglement takes place, the layering is suppressed due to intermolecular correlation. Furthermore, the layering substantially reduces the loss modulus while exhibiting an oscillatory storage modulus with respect to the distance from the substrate. Consequently, alternating properties of solidity and fluidity depending on the distance emerge in the layered interfacial fluids. This coexistence of solid-like and fluid-like phases may provide clues to longstanding questions about the structure-property relations in fluids at interfaces. Our results provide a comprehensive understanding of the tribo-rheological properties of complex fluids across from nano- to bulk-scales.Abstracts i List of Figures vii 1. Introduction 1 1.1 Motivation 1 1.2 Outline of this work 3 2. QTF-AFM based rheometer 5 2.1 System overview – Atomic force microscopy 5 2.2 Theory of shear-mode AFM 10 2.3 QTF as a quantitative force sensor 11 2.4 Preamplifier of QTF 18 2.5 Response time of QTF sensor 21 2.6 Tapered stiffness for measuring shear force 25 2.7 DC supply for controlling piezoelectric-transducer 27 3. Theoretical background 31 3.1 Introduction 31 3.2 Modeling viscoelastic fluids 34 3.3 Maxwell relaxation time 41 3.4 Complex modulus calculation 43 3.5 Free energy analysis of polymer-wall interaction 49 4. Multiscale rheology 52 4.1 Introduction 52 4.2 Experimental process 54 4.3 Rheology across the scale 61 4.4 Conclusion 70 5. Interfacial structure of polymeric fluids 71 5.1 Introduction 71 5.2 Structure of interfacial polymeric fluids 73 5.3 Free energy theory 81 5.4 Rheological properties of interfacial polymeric fluids 85 5.5 Relaxation time of interfacial polymeric fluids 92 6. Aging effects of layered structures 101 6.1 Introduction 101 6.2 Time dependence of layered structures 104 6.3 Rheological studies of nanoscale aging effects 106 6.4 Nanoscale aging effects analyzed by Maxwell relaxation time 110 7. Conclusions 113 Appendix 116 Appendix A. 116 Appendix B. 119 Bibliography 125 Abstract in Korean 138 Publication list 140박

Impact of pelvic artery embolization on anti-Mullerian hormone levels in patients with postpartum hemorrhage: a prospective cohort study

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Analysis of Discrepancies Between Textbook Descriptions and Experimental Observations of Water Cooling and Suggestions for Improvement

본 연구에서는 중학교 과학 교과서에서 제시된 물의 냉각 곡선 실험과 실제 실험 결과 간의 불일치를 분석하고, 이를 해결하기 위한 개선 방안을 제안하였다. 교과서에서는 물이 냉각될 때 온도가 일정하게 감소하다가 0 ℃에서 응고가 일어나며 온도가 변하지 않는다고 설명하지만, 실제 실험에서는 과냉각 현상으로 인해 온도가 0 ℃ 이하로 떨어졌다가 갑작스럽게 상승하며 응고가 진행되었다. 또한, 실험에 소요되는 시간이 길어 수업 시간 내에 완료하기 어려운 점도 확인되었다. 이에 본 연구에서는 교과서의 실험 방법을 재현하고 불일치 현상의 원인을 탐구한 뒤, 개선된 실험 방법을 설계하였다. 이를 위해 냉각제의 온도를 –10 ℃ 이하로 유지하고, 물의 초기 온도를 높이며, 교반 자석을 사용해 대류를 촉진하여 과냉각을 최소화하고 실험 시간을 단축하였다. 이러한 개선을 통해 실제 실험 결과와 교과서의 설명 사이의 일치도를 높였으며, 교육 현장에서 보다 효과적으로 실험을 수행할 수 있게 되었다.N

TTD: Text-Tag Self-Distillation Enhancing Image-Text Alignment in CLIP to Alleviate Single Tag Bias

We identify a critical bias in contemporary CLIP-based models, which we denote as single tag bias. This bias manifests as a disproportionate focus on a singular tag (word) while neglecting other pertinent tags, stemming from CLIP embeddings prioritizing one specific tag in image-text relationships. In this paper, we introduce a novel two-step fine-tuning approach, Text-Tag Self-Distillation (TTD), to address this challenge. We first extract all image-relevant tags from text based on their similarity to the nearest pixels. Then, we distill a combined mask containing the extracted tags' content to a text-derived mask. This approach ensures the unbiased image-text alignment of the CLIP-based models using only image-text pairs without necessitating additional supervision. Our technique demonstrates model-agnostic improvements in multitag classification and segmentation tasks, surpassing competing methods that rely on external resources. The code and data are available at https://github.com/shjo-april/TTD.N

Contextual resources supporting the co-evolution of teachers' collective inquiry and classroom practice after the grant ended

We explored how various contextual resources accumulated over multiple years operated together to facilitate a team of high school teachers' sustained and agentive learning after a 4-year research-practice partnership (RPP) grant concluded. Specifically, we examined constellations of resources that promoted the co-evolution of the teachers' collective inquiry in the professional learning community (PLC) and classroom instruction, focused on supporting students' scientific explanations. We qualitatively analyzed the video/audio recordings of the PLC members' interactions in eight 75-min PLC meetings (11 h) and a full-day professional development (8 h) and classroom teaching (34 lessons) over the period of 6 months. We found that the contextual resources accumulated from the historical 4-year RPP-including a culture of collaborative inquiry, collegial relationships, structures for teacher collaboration, and expertise embedded in individuals as well as co-developed tools and practices (cultural, social, structural, and expertise resources)-were important. These resources, in combination with emerging teacher leadership (leadership resource) and timely supports, such as school leadership and district-based funding for sustaining structures for collaboration (leadership and structural resources), enabled the teachers to launch and drive their own collaborative inquiry and shift instruction after the conclusion of the grant. The harmonized contexts led the teachers to learn across the PLC and classrooms by engaging in co-evolution mechanisms-setting goals based on classroom data, reasoning about instructional practices using various representations of teaching, and experimenting on a set of common practices across classrooms. This paper is part of the special issue on Teacher Learning and Organizational Contexts.Y

Distilling Diffusion Models Into Conditional GANs

We propose a method to distill a complex multistep diffusion model into a single-step conditional GAN student model, dramatically accelerating inference, while preserving image quality. Our approach interprets diffusion distillation as a paired image-to-image translation task, using noise-to-image pairs of the diffusion models ODE trajectory. For efficient regression loss computation, we propose E-LatentLPIPS, a perceptual loss operating directly in diffusion models latent space, utilizing an ensemble of augmentations. Furthermore, we adapt a diffusion model to construct a multi-scale discriminator with a text alignment loss to build an effective conditional GAN-based formulation. E-LatentLPIPS converges more efficiently than many existing distillation methods, even accounting for dataset construction costs. We demonstrate that our one-step generator outperforms cutting-edge one-step diffusion distillation models – SDXL-Turbo and SDXL-Lightning – on the COCO benchmark.

Influence of prestroke glycemic status on outcomes by age in patients with acute ischemic stroke and diabetes mellitus

Background: This study aimed to explore the association between admission HbA1c and the risk of 1-year vascular outcomes stratified by age group in patients with acute ischemic stroke (AIS) and diabetes mellitus (DM). Methods: This study analyzed prospective multicenter data from patients with AIS and DM. Admission HbA1C were categorized as:<= 6.0%, 6.1%-7.0%, 7.1%-8.0%, and >8.0%. Age was analyzed in categories:<= 55 years, 56-65 years, 66-75 years, 76-85 years, and >85 years. The primary outcome was 1-year composite of stroke, MI, and all-cause mortality. The modifying effect of age on the relationships between HbA1c and 1-year primary outcome was explored by Cox proportional hazards model. Results: A total of 16,077 patients (age 69.0 +/- 12.4 years; 59.4% males) were analyzed in this study. Among patients <= 55 years, the hazard ratio (HR) of the 1-year primary outcomes increased with an HbA1C > 8.0% (adjusted HR 1.39[1.13-1.70]). For patients aged 56-65 and 66-75, the highest HRs were observed for an HbA1c of 7.1-8.0% (aHRs; 1.21 [1.01-1.46] and 1.22 [1.05-1.41], respectively). In the 85+ age group, the highest HR occurred for HbA1c <= 6.0% (aHR 1.47 [0.98-2.19]). The HbA1c 8.0% showed evident age-dependent heterogeneity in the post hoc HR plots. Conclusion: Our study revealed that in patients with AIS and diabetes under 55, higher admission hbA1c was associated with an increased risk of the 1-year primary outcome, while in patients aged over 85, lower HbA1c value (<= 6.0%) may be associated with an increased risk of vascular events. The results of our study suggest the age-stratified, heterogeneous associations between admission HbA1c and 1-year vascular outcomes in patients with AIS and diabetes.Y