나노다공성 금 표면상에서 구조 변화에 따른 전기화학적 산소환원 촉매활성

최수희,최경민,김종원,Choi, Su-Hee,Choi, Kyoung-Min,Kim, Jong-Won 한국전기화학회 2012 한국전기화학회지 Vol.15 No.2

전기화학적 석출에 의해 Ag-Au 합금층을 전극표면에 형성한 후 진한 질산으로 Ag만을 녹여내는 기법으로 나노다공성 금(nanoporous gold, NPG) 구조를 만들어 전기화학적 산소환원에 대한 촉매현상을 관찰하였다. 석출과정의 전구체의 농도비를 달리하였을 때 나타나는 NPG 표면구조의 변화를 주사전자현미경으로 관찰하고 전기화학적 표면적을 측정하였다. 전기화학적 산소환원 촉매 효율은 NPG 표면의 구조에 따라 달라졌는데, Ag/Au 비율이 2.0에 해당하는 NPG 구조에서 가장 우수한 촉매 현상이 관찰 되었다. 표면구조의 변화에 따른 촉매 활성 변화에서 다공성 구조의 역할이 매우 큰 기여를 하는 반면 표면적의 변화는 큰 영향을 미치지 않았다. 최적 조건의 NPG 구조상의 전기화학적 산소환원 과정의 메커니즘을 회전원판전극 실험을 통해 관찰하였는데, 산성 조건에서 NPG 전극에서 전기화학적 산소환원은 과산화수소를 거쳐 물이 생성되는 2-단계 4-전자 환원 메커니즘으로 진행되었고 염기성 조건에서는 산소가 4개의 전자 전달을 통해 물로 직접적으로 환원 되었다. We investigate the electrocatalytic activities for oxygen reduction at nanoporous gold (NPG) surfaces fabricated by selective dissolution of Ag from electrodeposited Ag-Au layers on electrode surfaces. The structure of NPG was controlled by changing the concentration ratios of precursor metal complexes during the electrodeposition of Ag-Au layers and the corresponding surface morphology and surface area was examined. NPG structures with Ag/Au ratio of 2.0 exhibited the highest electrocatalytic activity for oxygen reduction, where the nanoporous structure plays a key role, but the surface area does not affect on the electrocatalytic activity. The mechanism of electroreduction of oxygen was investigated by rotating disk electrode techniques. In acidic media, oxygen was first reduced to hydrogen peroxide followed by further reduction to water through 2-step 4-electron mechanism, whereas the oxygen was reduced directly to water by 4-electron mechanism in basic media.

공을 이용한 안뜰계 훈련이 정상 성인의 정적 균형에 미치는 영향

최수희,조화영,강양훈,곽광일,권혜민,서삼기,Choi, Su-Hee,Cho, Hwa-Young,Kang, Yang-Hun,Kwank, Kwang-Il,Kwon, Hye-Min,Seo, Sam-Ki 대한임상전기생리학회 2011 대한임상전기생리학회지 Vol.9 No.2

Purpose : The purpose of this study is to investigate the effect on the static balance ability according to vestibular training using ball. Methods : Twenty normal subjects participated and were randomly assigned to either a vestibular training group using ball or a control group. The vestibular training using a ball group exercised 3 times per week over 3 weeks. The static balance was assessed by the center of pressure to the stance position. The participants stood barefoot on a force platform in a normal stance and a one-legged stance with a visual close. Results : In the normal stance, there were no significant differences at CoP surface and CoP speed. However, in a one-legged stance, there were significant differences in the vestibular training group between before and after the program. There was also a significant difference between the vestibular training group and the control group. Conclusion : Vestibular training using ball can be implemented as a therapeutic intervention to improve static balance ability in health adults.

스마트폰 앱을 활용한 초등영어 학습부진학생의어휘학습 사례연구

최수희 ( Su Hee Choi ),안경자 ( Kyung Ja Ahn ) 한국현대영어영문학회 2015 현대영어영문학 Vol.59 No.1

This study aims to investigate the vocabulary learning experiences of underachieving elementary English students while they used smartphone applications. Their vocabulary acquisition and vocabulary learning attitudes according to the application type they used were also examined. The participants were eight fifth-grade underachievers who were divided into two 4-person groups who used word card and game-type applications, respectively. Each student participated in his or her assigned vocabulary-learning activities for about twenty minutes each weekday for 9 weeks. The data sources included student interviews, the teacher’s journal, surveys of the students about their vocabulary learning attitudes, and their vocabulary tests. The findings revealed that the students’ lack of motivation, weak concentration, and repeated failure experiences could be overcome by giving rewards, re-creating a learning environment, and offering the opportunity to experience success. Also, obstacles such as technological problems with the smartphones and insufficient time at school to study vocabulary with the applications were surmounted by gaining the cooperation of the participants’ families and encouraging the students’ practice of self-directed learning. It was also found that through using smartphone applications, the learners’ vocabulary skills and the attitudes of most of the participants towards English vocabulary learning improved. Both applications had a positive effect on the underachievers’ vocabulary learning and attitudes, while the group using the word card application showed slightly higher achievement. Important implications regarding teaching and learning English vocabulary using smartphone applications are also discussed.(Suwn Songjook Elementary School, Seoul National University of Education)

발 뒤꿈치 높이가 젊은 성인 여성의 균형능력과 감각에 미치는 영향

최수희 ( Su-hee Choi ),서재근 ( Jae-gun Seo ),이상호 ( Sang-ho Lee ) 대한신경치료학회 2017 신경치료 Vol.21 No.3

Purpose The purpose of this study is to investigate the change of dynamic and static balance ability and the change of sensory system in the ankle region by wearing shoes with different heel heights. Methods This study was conducted for 30 women attending S university in Nam-won city for 4 weeks from September 5, 2016 to October 2, 2016.The study group(n=15) was wearing shoes with a heel height of 7 cm and the control group(n=15) was wearing shoes with a heel height of 3 cm for more than 8 hours per day for 4 weeks. The dynamic balance ability was assessed using the Y-Balance Test, the static balance ability was assessed using FICSIT-, and the sensory identification test was using the two-point discriminant test. Results Differences in static balance ability within the study group were statistically significant(p<.05). The difference of static balance ability between study group and control group was significant(p<.05). The difference in the two-point discrimination ability between the study group and the control group was statistically significant(p<.05). Conclusion The group wearing high - heeled shoes had low sensitivity to sensation and low static balance ability. Therefore, it is considered that high - heeled shoe is difficult to maintain balance by increasing foot fatigue and lowering sense of body.

국내 지역별 매립 복령의 성분 및 항산화 활성 비교

최수희 ( Su Hee Choi ),이승진 ( Seung Jin Lee ),조우식 ( Woo Sik Jo ),최종운 ( Jong Woon Choi ),박승춘 ( Seung Chun Park ) 한국균학회 2016 韓國菌學會誌 Vol.44 No.1

This study was conducted for comparison of ingredients, phytochemical compounds and antioxidant activity of Wofiporia extensa cultured in Gangwon-do, Gyeongsang-do, and Jeolla-do. Three contents of Wofiporia extensa were analyzed as oxygen (46~48%), carbon (38~39%), hydrogen (6.05~6.1%) and nitrogen (0.17~0.21%). The mineral contents of 50% ethanol Wofiporia extensa extracts were measured as sulfur (S) 145~149 ppm, Magnesium (Mg) 69~72 ppm, phosphorus (P) 122~154 ppm and calcium (Ca) 210.61~509.98 ppm. Wofiporia extensa from Gyeongsang-do (509.98 ppm) contained a significantly higher quantity of Ca than that from Gangwon-do (210.62 ppm) and Jeolla-do (223.88 ppm). In the gas chromatograph-mass spectrometry (GC-MS) analysis, oleic acid was identified in three 50% ethanol Wofiporia extensa extracts. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2`-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay for antioxidant activity, the IC50 values of Wofiporia extensa cultured in Gangwon-do, Gyeongsang-do and Jeolla-do were calculated as 2.966 mg/mL, 23.03 mg/ mL, and 4.16 mg/mL and 3.521 mg/mL, 12.17 mg/mL, and 7.40 mg/mL. In the ferric reducing antioxidant power (FRAP) assay, the IC50 values of Wofiporia extensa cultured in Gangwon-do, Gyeongsang-do, Jeolla-do were 6.585 mg/mL, 19.06 mg/mL, and 18.97 mg/mL, respectively. In summary, Wofiporia extensa cultured in Gangwon-do had stronger antioxidant activity and higher concentration of oleic acid than that of Geyongsang-do and Jeolla-do. However, Wofiporia extensa cultured in Geyongsang-do contained a much higher concentration of Ca than that of Gangwon-do and Jeolla-do.

스위스 볼을 이용한 체간 안정화 운동과 코어 안정화 운동이 여성노인의 균형과 보행에 미치는 영향

최수희 ( Su Hee Choi ),임재헌 ( Jae Heon Lim ),조화영 ( Hwa Young Cho ),김일복 ( Il Bok Kim ),김모경 ( Mo Kyung Kim ),이현영 ( Hyun Young Lee ) 대한물리의학회 2012 대한물리의학회지 Vol.7 No.1

Purpose:The purpose of this study was to investigate the effects of trunk stabilization exercise using swiss ball and core stabilization exercise on balance and gait in elderly women. Methods:Subjects 19 elderly women were randomly divided by the swiss ball exercise group (n=10) and the core stabilization exercise group (n=9). In a period of 4 weeks, they took trunk stabilization exercise using swiss ball and core stabilization exercise for 60 minutes 3 times a week. Balance and gait were measured by Functional Reach Test (FRT), One Leg Stand Test with Open Eye (OLSTOE), One Leg Stand Test with Closed Eye (OLSTCE), Timed Up and Go Test (TUG) and 6 m Walking Test (6MWT). These tests were measured at before exercise, 4 weeks after exercise and after the follow-up period of 2 weeks. Results:As a result, in all measurement values there was no significant difference in two groups (p>.05). In FRT, TUG, OLSTOE and 6MWT before exercise and 4 weeks after exercise, there was significant difference in both of two groups (p<.05). Moreover, according to results from 4 weeks after exercise and after the follow-up period of 2 weeks, without any particular exercise, in FRT and 6MWT there was no significant difference (p>.05). Conclusion:These finding indicate that trunk stabilization exercise using swiss ball could improve balance and gait in elderly women. Accordingly, In this study trunk stabilization exercise using swiss ball and core stabilization exercise is judged to be used for elderly people with gait and balance problems to prevent hurts from fall.

A Clinical Study and assays of P53 expression in 43 Cases of Uterine Sarcomas

최수희 ( Soo Hee Choi ),( Jae Weon Kim ),( Sang Young Ryu ),( Su Yeon Kim ),( Noh Hyun Park ),( Yong Sang Song ),( Soon Beon Kang ),( Hyo Pyo Lee ) 대한산부인과학회 1997 대한산부인과학회 학술대회 Vol.80 No.-

성별에 따른 몸통근육의 초음파 영상 구조 비교

임재헌 ( Jae Heon Lim ),최수희 ( Su Hee Choi ),서삼기 ( Sam Ki Seo ) 대한물리의학회 2015 대한물리의학회지 Vol.10 No.2

PURPOSE: The purpose of this study is to compare ultrasound images of trunk muscles according to gender in healthy subjects. METHODS: Twenty six subjects(13 males and 13 females) were enrolled in this study. The thickness of trunk muscles was measured for transverse abdominis (TrA), external oblique abdominis (EOA), internal oblique abdominis (IOA), and multifidus (MF) using ultrasound. The thickness of the muscles was measured for the length of cross-section except for fascia. The muscle thickness wasmeasured at the both side, then the mean value was calculated. Also, each of trunk muscle wasanalysed by echodensity, white area index. RESULTS: As a results, there was significant difference in muscle thickness of EOA, IOA according to gender (p<0.05). The male was significant increase than female of EOA, IOA in muscle thickness. There was significant difference in echo intensity of TrA, MF according to gender(p<0.05). The female was significant increase than male of TrA, MF in echo intensity. There was significant difference in white area index of EOA according to gender(p<0.05). The female was significant increase than male of EOA in white area index. CONCLUSION: The findings of this study suggest that healthy male have a greater EOA, IOA trunk muscle thickness than female. However, the difference of muscle quality between male and female was showed through thisexperiment. Therefore, the ultrasonography images will be useful tool for seeing quantitative and qualitative difference of trunk muscles according to gender.

무성폐쇄음의 기식음화 양상 : 미국영어와 영국영어의 비교

신승훈(Shin, Seung-Hoon),최수희(Choi, Su-Hee) 신영어영문학회 2013 신영어영문학 Vol.54 No.-

The issue of disparity between American English (AE) and British English (Received pronunciation; RP) has most typically been studied in the context of phonetics and phonology. The aim of this study is to explore different patterns of aspiration realizations in AE and RP in various phonetic, phonological and morphological contexts. The results indicates that values of VOT in RP is much longer than those in American English. The analysis revealed an interesting pattern: while comparison in terms of morphological environment between the languages was not significant, there were significant correlations between the languages and phonological environments, and the languages and places of articulations. Also, patterns of aspiration also applied over a word or an affix boundary on a regular basis similarly as the patterns of aspiration within a word, which clearly shows that aspiration is a postlexical rule. Finally, we contend that the differences between aspiration in AE and aspiration in RP are the consequence of two major phonetic forces, “ease of articulation” and “ease of perception”. (Yeungnam University)

온라인 증권 트레이딩 시스템의 유저 인터페이스 컨설팅 프로세스에 관한 연구

권용(Yong Kwon),박태성(Tae-Sung Park),허정욱(Jeung-Uk Huh),최수희(Su-Hee Choi),이지현(Ji-Hyun Lee) 한국HCI학회 2003 한국HCI학회 학술대회 Vol.2003 No.2