Direct Observation of Inherent Atomic-Scale Defect Disorders responsible for High-Performance Ti₁₋<i>_x</i> Hf<i>_x</i> NiSn₁₋<i>_y</i> Sb<i>_y</i> Half-Heusler Thermoelectric Al

Kim, Ki Sung,Kim, Young-Min,Mun, Hyeona,Kim, Jisoo,Park, Jucheol,Borisevich, Albina Y.,Lee, Kyu Hyoung,Kim, Sung Wng Wiley (John WileySons) 2017 Advanced Materials Vol.29 No.36

<P>Structural defects often dominate the electronic- and thermal-transport properties of thermoelectric (TE) materials and are thus a central ingredient for improving their performance. However, understanding the relationship between TE performance and the disordered atomic defects that are generally inherent in nanostructured alloys remains a challenge. Herein, the use of scanning transmission electron microscopy to visualize atomic defects directly is described and disordered atomic-scale defects are demonstrated to be responsible for the enhancement of TE performance in nanostructured Ti1-xHfxNiSn1-ySby half-Heusler alloys. The disordered defects at all atomic sites induce a local composition fluctuation, effectively scattering phonons and improving the power factor. It is observed that the Ni interstitial and Ti,Hf/Sn antisite defects are collectively formed, leading to significant atomic disorder that causes the additional reduction of lattice thermal conductivity. The Ti1-xHfxNiSn1-ySby alloys containing inherent atomic-scale defect disorders are produced in one hour by a newly developed process of temperature-regulated rapid solidification followed by sintering. The collective atomic-scale defect disorder improves the zT to 1.09 +/- 0.12 at 800 K for the Ti0.5Hf0.5NiSn0.98Sb0.02 alloy. These results provide a promising avenue for improving the TE performance of state-of-the-art materials.</P>

Changes in the quadriceps-to-hamstring muscle ratio during wall squatting according to the straight leg raise test angle

Kim, Jaeeun,Kim, HyeonA,Lee, JuYeong,Lee, HoYoung,Jung, Hyoseung,Cho, YunKi,Choi, HyeMin,Yi, Donghyun,Kang, Daewon,Yim, Jongeun korean Academy of Physical Therapy Rehabilitation 2019 Physical therapy rehabilitation science Vol.8 No.1

Objective: The purpose of this study was to investigate the muscle activity ratio of the lower limb according to changes in straight leg raise (SLR) test angles on hamstring muscle shortening during squat exercises. Design: Randomized controlled trial. Methods: The subjects were 14 healthy adults who were informed of and agreed to the method and purpose of the study. The participants were classified into SLR groups according to two angles (over $80^{\circ}$ or under $80^{\circ}$) assessed using the SLR tests. After training and practicing the wall squat posture to be applied to the experiment, electromyography (EMG) was used to measure changes in muscle activity during the performance of a wall squat. After stretching, a sequence of pre-stretch tests were performed again, and the active and passive SLR tests were also reconducted; thereafter, a wall squat was performed again by attaching EMG electrodes. The EMG results before and after stretching were compared. Results: The muscle activity of the vastus lateralis oblique muscle increased in both groups. The muscle activity of the vastus medialis oblique muscle decreased in over both group. Rectus femorus activity increased in the under 80-degree groups but decreased in the over 80-degree group. The muscle activity of the biceps femoris muscle decreased after stretching in the over 80-degree group and increased in the under 80-degree group, and the semitendinosus muscle activity after stretching was decreased. The quadriceps-to-hamstring muscle (Q:H) ratio before and after stretching between groups showed that the hamstring muscle ratio decreased after stretching in both groups. Conclusions: The results of this study showed that the Q:H ratio before and after stretching between groups was not significantly different.

Synthesis of jet fuel through the oligomerization of butenes on zeolite catalysts

Kim, Hyeona,Kim, Daaye,Park, Young-Kwon,Jeon, Jong-Ki Springer-Verlag 2018 Research on chemical intermediates Vol.44 No.6

Natural History and Influencing Factors of Chronic Urticaria in Children

Kim HyeonA,Hyun Myung Chul,Choi Bong Seok 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.1

Purpose: Chronic urticaria (CU) can reduce the quality of life of children and their parents, but there are only a few studies on the course of CU in children. This study aimed to investigate the natural course of CU in children and identify the factors that influence its prognosis. Methods: We evaluated 77 children diagnosed with CU, who were monitored for at least 48 months. Subjects were classified as either chronic spontaneous urticaria (CSU) or other CU, and the clinical features were compared. Remission was defined as having no symptoms without treatment for more than 1 year. The remission rate was analyzed, and the factors influencing the prognosis were investigated. Results: The average age of the study population was 5.96 ± 4.06 years, and 64 (83.1%) patients had CSU. The remission rates at 6 months, 1 year, 2 years, 3 years, and 4 years after symptom onset were 22.1%, 40.3%, 52.0%, 63.7%, and 70.2%, respectively, for children with CU. For children with CSU, these values were 23.4%, 43.7%, 56.2%, 68.7%, and 75.0%, respectively. The total serum immunoglobulin E (IgE) levels were positively correlated with disease duration (r = 0.262, P = 0.021); no other factors were associated with the duration of the disease. Conclusions: A high proportion of children with CU were classified as CSU. No indicators, except for total IgE were found to predict the timing of spontaneous remission. The CU remission rate identified in this study is expected to be used as one of the reference data for the progress of CU in patients.

효율성과 투명성을 확보한 블록체인 기반 전자투표 및 설문조사 시스템

김현아(HyeonA Kim),나연주(YeonJu Na),이재윤(JaeYun Lee),정유리(YuRi Jeong),김형종(Hyung-Jong Kim) 한국시뮬레이션학회 2021 한국시뮬레이션학회 논문지 Vol.30 No.4

전자투표는 기존 종이 투표의 한계를 보완하는 대안으로 주목을 받아왔다. 동시에 보안에 대한 우려가 제기되고 있다. 본 논문에서는 신뢰성을 보장할 수 있는 블록체인 기반 전자투표 및 설문조사 시스템을 제시한다. 블록체인 기반 분산 컴퓨팅 플랫폼인 이더리움의 Solidity를 사용해 스마트 컨트랙트를 작성하고, Javascript 기반의 사용자 인터페이스와 연계해 시스템을 구현하였다. 더불어 참여자의 개인정보를 보호하기 위해 회원가입 시 정보를 해시함수로 암호화하여 저장하도록 설계했다. 이러한 이종의 언어를 기반으로 한 복잡한 개발 환경에서 정상적인 동작 수행 여부를 검증하기 위해 점검 항목을 정하여 이의 점검 결과를 제시하였다. 또한, 사용자의 경험을 고려한 성능을 평가하기 위해 Chrome의 Performance 측정 도구를 사용하여 블록체인 미사용 환경과 비교하여 평가결과를 제시하였다. 본 연구 결과의 기여점은 블록체인 기반의 전자투표 시스템의 설계와 구현 및 이의 기능과 성능평가를 위한 시뮬레이션 결과의 제시에 있다. Electronic voting has been recognized as an alternative to complement the limitations of existing paper voting. At the same time, security concerns are being raised. This paper presents a blockchain-based electronic voting and survey system that can guarantee reliability. Our smart contract was created using Solidity on Ethereum which is a blockchain-based distributed computing platform, and the system was implemented in connection with the Javascript based user interface. In addition, in order to protect the personal information of participants, the system is generating hash of the personal data and storing the hash of users for the contract data. Since we exploited different kinds of languages for the system, we derived items of functionality testing and presented the functionality testing result. Moreover, we made use of the Chrome’s performance evaluation functionality to see the response time of the blockchain-based system. In addition, we compared the performance with the system which has the same functionality on database. The contribution of this research is design and implementation of blockchain-based electronic voting system and presentation of the functionality and performance simulation result.

죽음, 새로운 탄생을 알리는 기적 - 에르베 기베르의 소설 『천국 Le Paradis』의 분석

김현아(KIM Hyeona) 프랑스문화예술학회 2021 프랑스문화예술연구 Vol.75 No.-

본 연구는 기베르의 소설 『천국』에서 ‘죽음, 새로운 탄생을 알리는 기적’이라는 주제로 천국의 의미를 재성찰했다. 화자는 천국 같은 섬에서 제인의 익사체를 발견한다. ‘산호초’는 치명적인 바이러스처럼 그녀를 사지로 내몬 ‘죽음의 덫’으로 비친다. 제인의 죽음은 화자를 기억상 실증, 정신분열증과 같은 ‘광기의 바다’에서 요동치게 한다. 정상 궤도에서 일탈한 그의 정신 상태는 HIV로 육체에 나타나는 이상 증세를 암시한다. 그런데도 그는 에이즈에 걸린 사실을 부인하는데, 이것은 불치병 환자가 아닌 새로운 자아를 구축하려는 발상이다. 그는 초자연적 존재를 찾아 ‘아프리카’로 떠나지만, ‘영원에 대한 환상은 죽음의 실체’ 앞에서 사라진다. 작가는 짧은 생을 예감하고 소설을 통해 영생의 길을 모색했다. 사후에 출간된 『천국』은 삶과 죽음을 초월하며 되돌아온다. 이것이 자기 파괴로 탄생한 천국의 실체이다.

후천성면역결핍증과 예술 작품의 탄생

김현아(Hyeona KIM) 프랑스문화예술학회 2018 프랑스문화예술연구 Vol.65 No.-

과제유형에 따른 순환 과제훈련이 뇌졸중 환자의 우울감 및 삶의 질에 미치는 효과

김현애 ( Kim Hyeonae ) 대한통합의학회 2017 대한통합의학회지 Vol.5 No.1

Purpose : This study is to examine the effects of different task-related circuit training by types of tasks on the depression and quality of life in stroke patients. Method : Forty-four chronic stroke patients were divided into a dual motor circuit task training group, a dual cognitive circuit task training group and a simple task training group. Over the course of eight weeks, before training, all the patients were identically encouraged to receive conservative physical therapy for 30 minutes, five times a week for a total of eight weeks with individual additional tasks. The dual motor circuit tasks training consisted of continuous circuit training motor tasks and additional motor tasks and the dual cognitive circuit task training consisted of tasks combining the same circuit training motor tasks and additional cognitive tasks. The simple task training consisted of natural walks on a flat terrain to the front, rear and lateral sides of the terrain. Result : As for the Stroke-Specific Quality of Life(SS-QOL) that showed significant diffe rences in comparison between the groups over the training period, the dual motor circuit task training group showed statistically significant differences in both different types of tasks at 8 weeks(p<.05). The score of Hospital Anxiety and Depression Scale(HADS) decreased in three groups, in the HADS showed significant changes over the training time in the three training groups(p<.05). Conclusion : It could be seen that the practical and continuous dual circuit task training was more effective than simple task training on quality of life. In comparison between the types of dual tasks, the dual motor circuit task training group showed more effects than the dual cognitive circuit task training group. This researcher hopes that the results of this study will be actively applied as rehabilitation methods for chronic stroke patients.

제라르 마세의 시집 La Memoire aime chasser dans le noir 연구 -사진 이미지 중심으로

김현아 ( Hyeona Kim ) 한국불어불문학회 2015 불어불문학연구 Vol.0 No.103

Ce travail vise a mettre en evidence le rapport qu’entretient la creation litteraire et l``image dans La Memoire aime chasser dans le noir. Comme le remarque Laurent Demanze, Gerard Mace y a cree 《une poetique de la memoire》grace a 《la precision des savoirs et l``enchantement de la reverie》. La tradition classique, comme la mythologie et le symbolisme, traverse cette œuvre. Notre analyse mettra en valeur trois aspects principaux : la fantaisie de la memoire, l``autre, et le signe de la mort et l’illusion de l’eternite. Gerard Mace puise l``essence de sa poesie dans son enfance. Ses memoires personnelles ressuscitent des images photographiques et des reves regrettes : les reves aussi 《brefs que l``eclair photographique》fuient vers 《le Lethe》. La photo et les reves evoquent 《Eurydice》, personnage de la mythologie grecque, et sa disparation. Les mythes qui constituent une memoire collective sont ainsi integres a la memoire personnelle de l’auteur, a son enfance. La memoire est un element essentiel a la source de toute creation ; elle est a la fois 《retrospective et prospective》comme le souligne Carlo Pasi. Gerard Mace recherche son identite en la mettant en relation avec d``autres. En effet semblant transcrire fidelement le reel, les photos, les reves et les reflets ne sont en fait que les images d’un ‘autre`` qui font entrer le doute en soi. ``L``autre`` resulte de la distance fonciere entre le referent et l``image. Le poete explore l``entite mysterieuse de l``existence. Il s``interroge sur l``identite en citant Amour, Phœbus, Lusignan, Biron dans “El Dechiado”, poesie de Nerval. De meme, des poetes tels que Baudelaire et Nerval, omnipresents dans les œuvres de Gerard Mace, rappellent l``existence de ``l``autre``. Les references a ces personnages medievaux et mythiques et a ces poetes aggravent la crise d``identite. Or ce conflit interieur semble etre un processus essentiel pour determiner son identite. C’est ce que souligne Laurent Demanze lorsqu’il evoque la necessite d``une 《alterite》germinatrice dans 《la genese de l``identite》. L``image de ``l``autre`` apparaissant comme un double cree un sentiment d’etrangete. Le double narcissique eveille un soupcon sur l’identite qui pourrait menacer la vie. C``est ``un signe`` de la mort que nous retrouvons dans la photographie. Le photographe serait comme un messager annonciateur de la mort et les photographies, ses victimes. Leur rapport fait penser a celui des Africains et des photographes occidentaux en Afrique qui volent 《les ames a travers les images》. Pourtant, nous observons l``energie dynamique de la vie palpiter dans la photo immobile. Le temps dans la photo s``emmele : le passe dans la photo revient en tant que passe et les spectateurs oscillent entre le passe et le present. Sylviane Agacinski qualifie ce concept d’ 《anachronisme》. Nous liberant de la peur de la mort, la photo nous laisse ainsi aspirer a la survivance. Mais malgre l``apparence de vie, la photo n``est qu``une image vide qui fait rever en vain de la vie eternelle. La memoire du poete transparait sous la forme de la photo, enigme temporelle a dechiffrer. Produit de la civilisation mecanique, la photo implique un monde spirituel, celui du reve, de l``inconscient, de la mort voire de l``eternite. Grace a l``imagination, la memoire du passe, personnelle et collective, source de l``invention, ouvre la porte de l``avenir. L’originalite de la poesie de Gerard Mace reside dans ce travail de rememoration.

히트펌프 및 열교환기 내 금속 표면 서리 생성 방지를 위한 초소수성 코팅 기술에 관한 연구

유현아(Hyeona Yu),김지율(Jiyull Kim),김상빈(Sang Bin Kim),황성범(Seong Bum Hwang),김혜진(Hye jin Kim),주지봉(Ji Bong Joo) 한국에너지기후변화학회 2023 한국에너지기후변화학회 학술대회 Vol.2023 No.11