https://scholarworks.sookmyung.ac.kr/handle/2021.sw.sookmyung/789 2026-02-28T01:39:49Z https://scholarworks.sookmyung.ac.kr/handle/2020.sw.sookmyung/162688 Title: Independent mass–stiffness tuning for efficient shear wavefront manipulation Authors: Park, Chan-wook; Park, Chung Il; Kim, Yoonyoung Abstract: Independent tuning of material properties enables the exploration of physically unattainable wave characteristics, providing a central strategy for advanced wave control. While such strategies have been applied to volumetric (longitudinal) waves, their extension to shear (transverse) waves remains limited due to fundamental physical challenges, namely that the particle motion is orthogonal to the wave vector, making mass–stiffness decoupling inherently elusive. The key novelty of this study lies in the unique design concept that enables independent control of the material parameters governing shear waves. Here, we present an elastic metasurface that achieves independent control of vertical mass density and shear modulus by employing dedicated substructures within each unit cell. The mass-controlling substructure can amplify its effective mass without affecting stiffness, while the stiffness-controlling substructure weakens its effective stiffness without altering mass, thereby realizing the desired effective mass-stiffness properties. This simultaneous but independent manipulation strategy of mass and stiffness is the key to realizing impedance matching and arbitrarily reduced phase velocity required to form a high-transmission shear wavefront in a desired pattern. Numerical and experimental validations confirmed that the proposed control method is effective in beam steering and focusing. Accordingly, this approach not only advances shear-wave control into previously unexplored regimes of material properties but also shows its potential for independent tunability of more complex elastic properties in solids. © 2025 Elsevier Ltd 2026-01-01T00:00:00Z https://scholarworks.sookmyung.ac.kr/handle/2020.sw.sookmyung/162768 Title: Hyper-Gain omnidirectional ultrasonic SH waves by overlapping dual Fabry-Perot Meta-Superstrates Authors: Lee, Hyuk; Park, Jun Hyeong; Kim, Hong Jae; Kim, Yoon Young Abstract: Omnidirectional ultrasonic wave manipulation is critical for non-destructive evaluation and structural health monitoring due to its advantage in simultaneous monitoring of broad inspection areas. However, omnidirectionality inherently suffers from energy dissipation with distance, seriously harming inspection quality in the far field. Here, we propose novel elastic meta-super-strates (EMSs) to achieve extraordinary gain in omnidirectional ultrasonic SH wave emission. Each EMS creates dual Fabry-Perot cavities (an internal cavity and an edge cavity) that confine source energy and release it in a highly amplified manner under precise resonance conditions. Multiple EMSs can be overlapped for cumulative amplification, with the total gain proportional to the product of individual impedance ratios. We establish a rigorous theoretical foundation for this emission enhancement using an effective medium model and validate the gain principle with single and multiple EMS configurations. Numerical simulations and experimental results confirm the hyper-gain phenomenon, demonstrating excellent agreement with theoretical predictions. The proposed EMS concept provides a practical approach for enhancing the omnidirectional performance of ultrasonic transducers. 2026-01-01T00:00:00Z https://scholarworks.sookmyung.ac.kr/handle/2020.sw.sookmyung/162811 Title: Effects of rehabilitation exercise programs on respiratory function, muscle strength, and exercise performance ability in individuals with spinal cord injury: a pilot randomized controlled trial Authors: Park, Se-Hee; Lee, Na Young; Lee, Min-Goo Abstract: Cardiopulmonary dysfunction is a critical complication following spinal cord injury (SCI), yet conventional rehabilitation often focuses narrowly on inspiratory training. This study aimed to evaluate a novel, multicomponent program that integrates respiratory, strength, and aerobic training to improve overall cardiopulmonary health in this population. In this randomized controlled trial, 22 individuals with chronic SCI were assigned to an experimental (EXP) or a no-intervention control (CON) group. The EXP group underwent a 4-week supervised program of progressive, integrated exercises. Key outcomes included changes in respiratory function (spirometry), isometric shoulder strength, and exercise capacity (NetVO₂). The EXP group demonstrated significantly greater improvements than the CON group in all measured domains. Key respiratory outcomes, including maximal inspiratory pressure and peak expiratory flow, increased significantly, with a notable increase in forced vital capacity of 0.5 ± 0.6 L. Upper limb strength also improved substantially; for example, shoulder flexion strength increased by up to 3.2 ± 1.2 N. Furthermore, exercise capacity, measured by NetVO₂, increased by 2.7 ± 1.3 ml/kg/min (all p < 0.05). A structured, multidimensional exercise program that combines respiratory, strength, and aerobic training is a highly effective strategy for concurrently enhancing cardiopulmonary function, muscle strength, and aerobic capacity in individuals with SCI. These findings advocate for a holistic, integrated approach over single-modality training to optimize functional recovery. Clinical Research Information Service (CRIS; KCT0010320) 2026-01-01T00:00:00Z https://scholarworks.sookmyung.ac.kr/handle/2020.sw.sookmyung/162779 Title: 전쟁과 돌봄 - 『제시의 일기』를 통해 본 중일전쟁기 임시정부 가족의 일상과 젠더 Authors: 예지숙 Abstract: 본 연구는 2024년에 공개된 『제시의 일기』 원본을 대상으로 중일 전쟁기 대한민국임시정부 독립운동가 부부의 일상과 육아 그리고 그 속에서 전개된 젠더 관계를 분석하였다. 본격적 내용 분석에 앞서 기존의 편집본(1999년, 2019년)에 대한 사료 비판을 시도하였다. 그 결과 편집본은 후대의 감상과 해석이 덧붙여지고 임시정부의 이동이나 해방 등의 거시적 사건을 중심으로 편집된 회고록의 성격을 띠고 있음을 밝혔다. 향후 『제시의 일기』를 활용할 때, 사료 비판에 유념하면서 원본과 편집본을 구분하여 활용해야 할 것이다. 일기 원본을 분석할 결과 일기는 날씨, 아이의 성장과 건강, 여가, 공적 기념일은 물론 가족의 기념일, 피난 등의 일상과 육아의 기록에 집중되어 있었다. 양우조는 아이들과 많은 시간을 함께 보내면서 정서적 교감을 활발하게 하였고 ‘스위트 홈’을 꾸리는 데도 노력하였다. 특히 최선화가 한국애국부인회 등 정치단체에서 활동하거나 와병 중일 때에 아이들을 전담하다시피 하면서 돌보았는데 이러한 아버지의 돌봄은 당대의 상황에서 쉽게 볼 수 없는 모습이었다. 최선화는 가사 노동 등 육체적이고 물리적 돌봄을 전담하면서 임시정부의 여성 단체에서 활동하였다. 이는 망명지 특히 전쟁기에 독립운동이라는 공동의 목표를 둔 부부의 상호 협력의 결과로 유연한 젠더 관계의 형성을 살펴볼 수 있었다. 그리고 전쟁 속 부부의 생활이 육아를 중심으로 한 단단한 일상을 바탕으로 하였음을 알 수 있었다. 공습과 대피가 일상화되고 물가 상승으로 어려움을 겪는 와중에 가족은 반공호 대피에 필요한 아이의 간식 예산을 세우고 기념일, 산보, 쇼핑 등의 여가를 지속하며 전쟁에 적응하고 있었다. 결과적으로 『제시의 일기』는 단순한 회고록이 아닌, 전쟁이라는 특수한 상황 속에서 독립운동가 부부가 겪은 개인의 일상적 실천과 젠더 관계를 생생하게 보여주는 중요한 1차 사료로 독립운동사뿐 아니라 향후 한국 근현대 젠더사와 가족사 연구에 있어 더욱 풍부하고 심층적인 논의를 가능하게 한다.; This study analyzes the original manuscript of Jessie’s Diary, made public in 2024, to examine the daily life, childcare practices, and gender relations of an activist couple within the Provisional Government of the Republic of Korea during the Sino-Japanese War. Prior to the main analysis, this study attemps a historiographical critique of the previously published editions (1999, 2019). The findings reveal that these edited versions possess the character memoirs, embelished with subsequent reflections and interpretations, and structured around macro-historical events such as the Provisional Government’s migration and national liberation. Therefore, future research utilizing Jessie’s Diary must be mindful of this critique and distinguish between the original manuscript and the edited versions. An analysis of the original manuscript reveals that the records are concentrated on daily life and childcare, covering weather, the child’s growth and health, leisure, and public and family anniversaries, as well as evacuation. Yang Woo-jo (the husband) spent significant time with his children, engaging in active emotional communion and striving to create a “sweet home." Notably, he took on the role of primary caregiver when Choi Sun-hwa (the wife) was active in political organizations, such as the Korean Patriotic Women’s Association, or when she was ill. This level of paternal care was a rare sight in that era. Concurrently, Choi Sun-hwa undertook physical and material caregiving, including domestic labor, while simultaneously being active in the Provisional Government’s women’s organizations. This demonstrates the formation of flexible gender relations resulting from the mutual cooperation of a couple sharing the common goal of independence, particularly within the specific context of exile and war. Furthermore, the study confirms that the couple’s life during the war was grounded in a solid daily routine centered on childcare. Amidst routine air raids, evacuations, and economic hardship caused by inflation, the family adapted to the war by budgeting for the child’s snacks for air-raid shelters and maintaining leisure activities such as celebrating anniversaries, taking walks, and shopping. Consequently, Jessie’s Diary is not merely a memoir but a crucial primary source that vividly reveals the individual daily practices and gender relations of an independence activist couple under the specific circumstances of war. This study contributes to enabling richer and deeper discussions in the future study of modern Korean history, gender history, and family history. 2025-12-01T00:00:00Z