Wireless powered wearable micro light-emitting diodes

Lee, Han Eol,Lee, Daewon,Lee, Tae-Ik,Shin, Jung Ho,Choi, Gwang-Mun,Kim, Cheolgyu,Lee, Seung Hyung,Lee, Jae Hee,Kim, Yong Ho,Kang, Seung-Mo,Park, Sang Hyun,Kang, Il-Suk,Kim, Taek-Soo,Bae, Byeong-Soo,Le Elsevier 2019 Nano energy Vol.55 No.-

<P><B>Abstract</B></P> <P>Wearable displays are considered as a bilateral communication tool in the hyperconnected era. Although several electronic clothing display was demonstrated, high power consumption issue still remained. Here, we present wireless powered wearable μLEDs (WμLEDs) with excellent stability. A custom-designed wireless power supply system operated a 30 × 30 WμLED array on a fabric. The WμLED stability was intensively investigated under bending, stretching, 85 °C/85% relative humidity and artificial sunlight conditions, showing the suitability of WμLED outdoor usage. Finally, a passive-matrix WμLED display successfully emitted a brilliant red glow on a fabric.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Wireless powered wearable μLEDs (WμLEDs) with excellent stability was realized by a custom-designed wireless energy supply system on a fabric. </LI> <LI> WμLED stability was investigated under bending, stretching, 85 °C/85% relative humidity and artificial sunlight conditions, showing the suitability of WμLED outdoor usage. </LI> <LI> A passive-matrix WμLED display successfully emitted a brilliant red glow on a fabric. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Trichogenic Photostimulation Using Monolithic Flexible Vertical AlGaInP Light-Emitting Diodes

Lee, Han Eol,Lee, Seung Hyun,Jeong, Minju,Shin, Jung Ho,Ahn, Yuri,Kim, Daesoo,Oh, Sang Ho,Yun, Seok Hyun,Lee, Keon Jae American Chemical Society 2018 ACS NANO Vol.12 No.9

<P>Alopecia is considered an aesthetic, psychological, and social issue among modern people. Although laser-induced skin stimulation is utilized for depilation treatment, such treatment has significant drawbacks of high energy consumption, huge equipment size, and limited usage in daily life. Here, we present a wearable photostimulator for hair-growth applications using high-performance flexible red vertical light-emitting diodes (f-VLEDs). Flexible microscale LEDs were effectively fabricated by a simple monolithic fabrication process, resulting in high light output (∼30 mW mm<SUP>-2</SUP>), low forward voltage (∼2.8 V), and excellent flexibility for wearable biostimulation. Finally, trichogenic stimulation of a hairless mouse was achieved using high-performance red f-VLEDs with high thermal stability, device uniformity, and mechanical durability.</P> [FIG OMISSION]</BR>

Anatomical position of the mandibular canal in relation to the buccal cortical bone: relevance to sagittal split osteotomy

Han Eol Lee,Se Jin Han 대한구강악안면외과학회 2018 대한구강악안면외과학회지 Vol.44 No.4

Objectives: Classification of the degree of postoperative nerve damage according to contact with the mandibular canal and buccal cortical bone has been studied, but there is a lack of research on the difference in postoperative courses according to contact with buccal cortical bone. In this study, we divided patients into groups according to contact between the mandibular canal and the buccal cortical bone, and we compared the position of the mandibular canal in the second and first molar areas. Materials and Methods: Class III patients who visited the Dankook University Dental Hospital were included in this study. The following measurements were made at the second and first molar positions: (1) length between the outer margin of the mandibular canal and the buccal cortical margin (a); (2) mandibular thickness at the same level (b); (3) Buccolingual ratio=(a)/(b)×100; and (4) length between the inferior margin of the mandibular canal and the inferior cortical margin. Results: The distances from the canal to the buccal bone and from the canal to the inferior bone and mandibular thickness were significantly larger in Group II than in Group I. The buccolingual ratio of the canal was larger in Group II in the second molar region. Conclusion: If mandibular canal is in contact with the buccal cortical bone, the canal will run closer to the buccal bone and the inferior border of the mandible in the second and first molar regions.

Optogenetic control of body movements via flexible vertical light-emitting diodes on brain surface

Lee, Seung Hyun,Kim, Jeongjin,Shin, Jung Ho,Lee, Han Eol,Kang, Il-Suk,Gwak, Kiuk,Kim, Dae-Shik,Kim, Daesoo,Lee, Keon Jae Elsevier 2018 Nano energy Vol.44 No.-

<P><B>Abstract</B></P> <P>The microstimulation of specific neural populations of the brain is one of the facile and reliable methods used in neuroscience for deduction of functional movement, complex behavior and even long-range connectivity. Recent advanced biomedical tools now employ flexible optoelectronic devices combined with optogenetic mouse models to induce high spatiotemporal modulation of specific brain activity. However, most current applications are limited to activation of small functional regions using blue-light driven channelrhodopsin. In this report, we introduce flexible AlGaInP vertical light-emitting diodes (VLEDs) for perturbation of specific functional areas of mouse cortex. Micro-scaled LEDs effectively compress the conductive balls dispersed in anisotropic conductive film (ACF) resulting red light emissions with high optical power density, capable of stimulating motor neurons deep below layer III from the brain surface. Selective operation of pulsed red light from f-VLEDs induces mouse body movements and synchronized electromyogram (EMG) signals. The expression of chrimson, red-shifted channelrhodopsin, enables red-light excitation of targeted functional area of motor cortex. This demonstration opens new opportunities for entire cortical mapping, to explore the connectivity between undefined motor areas in the mouse brain.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The flexible vertical light-emitting diodes (f-VLEDs) were fabricated by an anisotropic conductive film (ACF). </LI> <LI> The f-VLEDs showed the optical power density more than 25mW/mm<SUP>2</SUP>, enough to stimulate the motor neurons below layer III. </LI> <LI> The f-VLEDs illuminated the frontal motor cortex of the mouse to control the body movements with minimal tissue damage. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

학부모가 인식하는 특수교육대상아동의 통합교육 참여에 대한 기대수준과 실행수준

이한얼 ( Han Eol Lee ) 한국지적장애교육학회(구 한국정신지체아교육학회) 2013 지적장애연구 Vol.15 No.2

이 연구는 학부모가 인식하는 특수교육대상아동의 통합교육 참여 수준을 알아보기 위하여 초등학교에서 통합교육을 받고 있는 특수교육대상아동의 학부모 83명을 대상으로 연구가 실시되었으며, 통합교육 참여 영역을 교과학습, 체험활동, 교우활동, 학교행사로 구분하고 이에 대한 학부모의 기대수준과 실행수준을 밝혔다. 이에 따른 연구 결과는 다음과 같다. 첫째, 학부모가 인식하는 특수교육대상아동의 통합교육 참여에 대한 기대수준이 실행수준보다 높다. 하위 영역인 교과학습, 체험활동, 교우활동, 학교행사에서 학부모가 인식하는 기대수준이 실행수준보다 높다. 둘째, 학부모가 인식하는 특수교육대상아동의 통합교육 관련 영역별 참여에 대한 기대수준과 실행수준을 살펴보면, 교과학습, 체험활동, 교우활동, 학교행사 영역의 모든 문항에서 학부모가 인식하는 기대수준이 실행수준보다 높다. 연구 결과에 따른 제언은 다음과 같다. 첫째, 특수교육대상아동의 통합교육 참여에 대한 기대수준과 실행수준 간의 차이가 큰 만큼 통합교육환경에서 특수교육대상아동의 참여를 보장하기 위한 다양한 방안이 마련될 필요가 있다. The purpose of this study is to investigate parents′ recognition about special education needs children′s participation tin inclusive education. To accomplish this purpose, a questionnaire was administered to 83 parents with special education needs children, and it analyzed their levels of expectation and performance in inclusive education areas divided by subject learning, experiential activities, friendship activities and school event activities. The results of this study are as follows: First, there is a significant difference between parents′ levels of expectation and performance of special education needs children′s participation in inclusive education. Parents′ levels of expectation of special education needs children′s participation in inclusive education are higher than their levels of performance. Parents′ levels of expectation are higher than their levels of performance in the areas of subject learning, experiential activities, friendship activities and school event activities. Second, parents′ levels of expectation are higher than their levels of performance in all items of subareas of subject learning, experiential activities, friendship activities and school event activities. The suggestions of these findings are as follows: First, it is necessary to study multiple dimensions of approach about special education needs children′s participation in inclusive education. Second, as a significant difference between parents′ levels of expectation and performance about special education needs children′s participation in inclusive education, there should be various ways to ensure special education needs children′s participation in inclusive education environment.

지적,발달장애인 지원 체계에 대한 이론적 근거 탐색

이한얼 ( Han Eol Lee ) 한국지적장애교육학회 2013 지적장애연구 Vol.15 No.1

양이온 교환막 수전해용 산화전극 확산층의 표면 특성 제어를 통한 전기화학적 성능 개선 연구

이한얼 ( Han Eol Lee ),( Doan Tuan Linh ),이우금 ( Woo-kum Lee ),김태근 ( Taekeun Kim ) 한국공업화학회 2021 공업화학 Vol.32 No.3

최근 화석 연료 고갈과 지구 온난화를 가속화하는 온실 가스 배출에 대한 우려로 온실 가스를 배출하지 않는 청정 에너지원인 수소 에너지 기술의 중요성이 강조되고 있다. 그 중 물을 전기분해하여 수소를 얻는 수전해 기술은 그린 수소 기술로 궁극적인 청정 미래 에너지 자원으로 주목받고 있다. 본 연구에서는 양이온 교환막 수전해(proton exchange membrane water electrolysis, PEMWE)의 셀 구성요소 중 하나인 확산층(porous transport layer, PTL)을 sandpaper를 이용한 표면 처리를 통하여 표면 특성을 제어하였으며, 이러한 표면 특성 개선을 통하여 과전압을 줄이고 성능과 안정성을 높이기 위한 연구를 진행하였다. Sandpaper 400, 180, 100방을 준비하여 PTL 표면을 sanding하여 처리하였으며, 처리 후 1000방의 고른 sandpaper로 표면을 매끄럽게 처리하였다. 준비된 확산층은 물접촉각을 측정하여 친수성 정도를 분석하였으며, SEM 분석을 통하여 표면 형태를 관찰하였다. 전기화학적 특성 분석을 위하여 I-V 성능곡선, 임피던스 측정을 진행하여 성능 개선 여부를 확인하였다. Recently, due to concerns about the depletion of fossil fuels and the emission of greenhouse gases, the importance of hydrogen energy technology, which is a clean energy source that does not emit greenhouse gases, is being emphasized. Water electrolysis technology is a green hydrogen technology that obtains hydrogen by electrolyzing water and is attracting attention as one of the ultimate clean future energy resources. In this study, the surface properties of the porous transport layer (PTL), one of the cell components of the proton exchange membrane water electrolysis (PEMWE), were controlled using a sandpaper to reduce overvoltage and increase performance and stability. The surfaces of PTL were sanded using sandpapers of 400, 180, and 100 grit, and then all samples were finally treated with the sandpaper of 1000 grit. The prepared PTL was analyzed for the degree of hydrophilicity by measuring the water contact angle, and the surface shape was observed through SEM analysis. In order to analyze the electrochemical characteristics, I-V performance curves and impedance measurements were conducted.

Fe-V Chloric/Sulfuric Mixed Acid 레독스흐름전지 전극의 활성화 온도에 따른 전기화학적 성능 고찰

이한얼 ( Han Eol Lee ),김대업 ( Dae Eop Kim ),김철중 ( Cheol Joong Kim ),김태근 ( Taekeun Kim ) 한국공업화학회 2020 공업화학 Vol.31 No.6

레독스흐름전지(redox flow battery, RFB)의 구성 부품 중 전극은 전해액의 확산층 역할을 함과 동시에 전자의 통로 역할을 담당하여 출력에 직접적인 영향을 미치는 주요 부품이다. 본 연구는 Fe²⁺/Fe³⁺와 V²⁺/V³⁺를 레독스 커플로 사용한 RFB 시스템에 chloric/sulfuric mixed acid 지지 전해액을 사용한 경우 전극 종류 및 활성화 정도에 따른 용량, 쿨롱 효율, 에너지 효율을 비교하여 최적의 전극 및 활성화 정도를 제시하였다. 실험에 사용된 5종의 탄소 전극을 사용한 단일셀 평가에서 모두 이론 용량에 근사한 값을 보여 신뢰성을 확보하였으며, 사용된 전극 중 GFD4EA는 상대적으로 우수한 에너지 효율 및 충방전 용량을 나타내었다. 활성화 온도에 따른 전기화학적 성능 고찰을 위하여 GFD4EA 전극을 공기분위기 하에서 400, 450, 500, 600 및 700 ℃에서 열처리하여 활성화하였다. 질량 변화, 주사전자현미경(SEM) 및 XPS 분석을 통하여 활성화 전 후의 물성 변화를 관찰하였으며, 각각의 온도에서 활성화된 전극을 적용한 RFB 단일셀 평가를 실시하여 전기화학적 성능을 비교하였다. Among the components of redox flow battery (RFB), the electrode serves as a diffusion layer of an electrolyte and a path for electrons and also is a major component that directly affects the RFB performance. In this paper, chloric/sulfuric mixed acidwas used as a supporting electrolyte in RFB system with Fe²⁺/Fe³⁺ and V²⁺/V³⁺ as redox couple. The optimum electrode and activation temperature were suggested by comparing the capacity, coulombic efficiency and energy efficiency according to the electrode type and activation temperature. In the RFB single cell evaluation using 5 types of carbon electrodes used in the experiments, all of them showed close to the theoretical capacity to retain the reliability of the evaluation results. GFD4EA showed relatively excellent energy efficiency and charge/discharge capacity. In order to investigate the electrochemical performance according to the activation temperature, GFD4EA electrode was activated by heat treatment at different temperatures of 400, 450, 500, 600 and 700 ℃ under an air atmosphere. Changes in physical properties before and after the activation were observed using electrode mass retention, scanning electron microscope (SEM), XPS analysis, and electrochemical performance was compared by conducting RFB single evaluation using electrodes activated at each temperature given above.

초등학교 통합학급 일반아동의 사회성 발달에 대한 교사와 학부모의 인식 비교

이한얼 ( Han Eol Lee ),조인수 ( In Soo Cho ) 한국지적장애교육학회(구 한국정신지체아교육학회) 2011 지적장애연구 Vol.13 No.1

이 연구는 통합환경에서의 교육이 일반아동의 사회성 발달에 미치는 영향에 관한 교사와 학부모의 인식 차이을 밝히고, 배경 변인에 따른 인식 수준을 살펴보았다. 이를 위해 사회성 발달을 자주성, 수용성, 사교성, 예절성의 하위영역으로 구성하여 교사 240명과 학부모 240명을 대상으로 설문을 실시하였다. 연구결과는 첫째, 통합학급 일반아동의 사회성 발달에 대해 교사가 학부모보다 긍정적으로 인식하고 있다. 둘째, 통합학급 일반아동의 사회성 발달에 대해 교사와 학부모 모두 통합 경험이 있는 집단이 통합교육 경험이 없는 집단보다 더 높은 인식 수준을 가진다. 이상의 연구결과에 비추어 통합교육 및 장애에 대한 인식을 개선하기 위해서 장애아동과 일반아동이 함께 적극적으로 어울리도록 또래지도나 상호협력학습 기회에서 사회성 기술 영역 별 프로그램을 구체적으로 제공할 필요가 있다. The purpose of this study is to investigate teachers` and parents` perceptions gaps of the sociality development of general children in integrated classes and to examine the level of perception according to their personal variables, For this, a questionnaire was comprised of autonomy, acceptance, sociability, and manner as subcategories of sociality development and data were collected from 240 teachers and 240 parents. The research findings were as follows. First teachers` perception of the sociality development of general children integrated classes is more positive than parents` perception. Second, both teachers and parents who had experience of integrated education have more positive perception on general children`s sociality development than those who had no experience. According to this result in order to improve recognitions on integrated education and disabilities, it is necessary to provide concrete programs for subcategories of sociality skill to associate actively both children with and without disabilities together.

학령기 이후 지적장애인의 진로 선택에 따른 지원요구

이한얼 ( Han Eol Lee ),조인수 ( In Soo Cho ) 한국특수아동학회 2012 특수아동교육연구 Vol.14 No.3

이 연구는 학령기 이후 지적장애인의 진로 선택에 따른 지원요구 수준을 밝히는 데 그 목적이 있다. 이를 위하여 장애인생활시설, 특수학교 전공과, 대학에서 생활하거나 교육을 받고 있는 집단으로 구분하고 각 집단에서 20명씩 총60명의 지적장애인들을 연구 대상으로 하였다. 면접자들은 검사대상의 특성에 대해 파악하고 있는 각 기관의 교사, 직원, 봉사자에게 응답을 받아 검사지를 작성하였으며, 검사지는 적응행동척도(K-SIB-R)와 지원요구척도(Supports Needs Scale)를 사용하였다. 연구 결과에 의하면 특수학교 전공과 배치 및 대학 진학 집단은 장애인생활시설 거주 집단보다 더 높은 지원요구를 가진다. 지적장애인의 지역사회통합에 무엇보다 중요한 것은 그들이 가진 개인적 능력이 아니라 그들의 특성과 그들이 처한 환경이 함께 고려된 지원을 충분히 받고 있는가의 여부에 달려있다고 볼 수 있다. 대학에 진학한 지적장애인들은 장애인생활시설에 거주하는 지적장애인들에 비해 지역사회생활, 평생학습, 고용, 사회적 활동 영역에서 더 높은 지원요구를 가진다. 그리고 특수학교 전공과에 배치된 지적장애인들은 장애인생활시설에 거주하는 지적장애인들에 비해 고용, 사회적 활동 영역에서 더 높은 지원요구를 가진다. 지적장애인들의 요구에 맞게 지원이 제공될 수 있다면 그들은 그들이 처한 환경에 적응하여 적절히 기능할 수 있다. 이 연구는 지적장애인들이 처한 환경에 따라 요구되는 지원의 영역과 수준이 다르므로 각 상황에 맞는 지원을 제공받아야 한다는 점과 지적장애인들도 그들의 특성과 환경이 함께 고려된 지원을 제공받음으로써 환경에 적응하여 적절히 기능할 수 있다는 점을 시사하고 있다. The purpose of this study was to analyze the support needs for post school individuals with intellectual disabilities according to career choice. The subjects of this study were divided into groups living or being educated in living faculties for the disabled, major courses at special schools, and colleges, and were composed of a total of 60 individuals with intellectual disabilities in 20 people each group. Questionnaires were written by interviewers to receive responses from teachers, employees, volunteers to identify the characteristics of the subject in each institution, and were used K-SIB and Support Needs Scale. As the results of this study, groups in major courses at special schools and groups in colleges have higher support needs than groups in living faculties. Most importance for community integration for individuals with intellectual disabilities is that depends on whether they are provided enough supports being considered their environment, not their personal abilities. Groups in colleges have higher support needs than groups in living faculties in activity subscales such as community living, lifelong learning, employment, and social. And groups in major courses at special schools have higher support needs than groups in living faculties in activity subscales such as employment and social. Individuals with intellectual disabilities can adapt and function properly to their environment if they are provided supports to meet their needs. This study suggests that intellectual disabilities should be provided context-sensitive supports due to the different areas and levels of support depending on their environment and they can adapt and function properly to their environment by receiving support being considered both their characteristics and environment.