세리아 안정화 지르코니아의 제조 및 특성(I) : CeO₂첨가량 변화에 따른 Ce-TZP의 기계적 특성

정승화,강종봉,Jung, Seung-Hwa,Kang, Jong-Bong 한국재료학회 2010 한국재료학회지 Vol.20 No.7

The usual ceramic process of mixing and milling in state of oxides $ZrO_2$ and $CeO_2$ was adopted in this study in a wet process to manufacture Ce-TZP. $CeO_2$-$ZrO_2$ ceramics containing 8~20 mol% $CeO_2$ were made by heat treatment at $1250\sim1500^{\circ}C$ for 5hr. The maximum dispersion point of every slurry manufactured with a mixture of $ZrO_2$ and $CeO_2$ was neat at pH10. A stable slurry with average particle size of 90 nm can be manufactured when it is dispersed with the use of ammonia water and polycarboxylic acid ammonium. The sintered Ce-TZP ceramics manufactured with the addition of $CeO_2$ in a concentration of less than 10 mol% progressed to the fracture of the specimen due to the existence of a monoclinic phase of more than 30% at room temperature. More than 99% of the tetragonal phase was created for the sintered body with the addition of $CeO_2$ beyond 18 mol%, but the degradation of the mechanical properties on the entire specimen was brought about due to the $CeO_2$ existing in a percentage above 3%. Consequently, the optimal Ce-TZP level combined in the oxide state was identified to be 16 mol% of $CeO_2$ contents.

뒤넙다리근 능동과 수동신장 운동이 요통 환자의 골반 가동성에 미치는 영향

정승화 ( Seung-hwa Jung ),박대성 ( Dae-sung Park ) 대한물리의학회 2021 대한물리의학회지 Vol.16 No.1

PURPOSE: Hamstring muscle shortening is related to low back pain, and it is important to check the hamstring muscle flexibility and pelvic mobility to analyze the effects of the intervention. This study examined the effects of hamstring muscle shortening on flexibility and pelvic mobility according to the method of stretching the hamstring muscle in patients with low back pain. METHODS: Forty Low Back Pain Patients participated. The subjects performed the Visual Analogue Scale (VAS), Fear Avoidance Belief Questionnaire (FABQ), Korean version of Oswestry Disability Index (KODI), Myovision, and sensbalance therapy cushion (pelvic mobility, proprioception). The subjects were divided into two groups to perform the passive and active stretching protocol. The intervention was conducted three times a week for four weeks. RESULTS: Hamstring muscle flexibility was increased significantly in both groups (p < .05), and there was no difference between the groups. VAS, FABQ was decreased significantly in both groups (p < .01), and there was no difference between the groups. The left lower back muscle impedance was decreased significantly in both groups (p < .05). The passive stretching group showed a significant increase in the pelvic anterior, posterior, and left tilt ROM (p < .05). The active stretching group showed a significant increase in the pelvic anterior, posterior tilt ROM (p < .05). CONCLUSION: Both stretching methods may be useful intervention methods for pelvic mobility and pain recovery and can assess back pain recovery.

개수로용 횡류수차의 흡출관 적용에 따른 성능연구

정승화(Seung-Hwa Jung),최영도(Young-Do Choi) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.춘계 No.-

터빈유입구 위치 및 각도에 따른 개수로용 횡류수차 성능연구

정승화(Seung-Hwa Jung),최영도(Young-Do Choi) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.춘계 No.-

MCT를 이용한 공인중개사의 도덕적 판단력에 관한 연구

정승화(Seung-Hwa Jung),신은정(Eun-Jung Shin) 건국대학교 부동산도시연구원 2018 부동산 도시연구 Vol.10 No.2

공인중개사의 윤리적 판단은 전문자격사와 전문직업인, 사회구성원으로서 중요한 요소임에도 불구하고 이를 평 가하는 척도는 매우 부족한 실정이며 제고방안에 대한 연구도 미흡한 실정이다. 따라서 본 연구는 이러한 필요성에 입각하여 공인중개사의 도덕적 판단력과 영향요인들에 대하여 고찰하고 이를 기초로 공인중개사의 윤리의식 제고방 안에 효과적인 방향을 제시하는데 도움이 되는 자료를 제공하는 것을 목적으로 한다. 이를 위하여 도덕성 측정 도구 중의 하나인 도덕 판단력 검사(Moral Competence Test)를 활용하여 2017년 8월 서울특별시의 개업공인중개사를 대 상으로 설문조사하여 분석하였다. 도덕적 판단력을 종속변수로 다중회귀분석한 결과, 연령이 높을수록 도덕적 판단 력이 낮아지는 것으로 분석되었고, 실제소득보다 낮은 수준으로 신고하여 간이과세자가 되는 간이과세자일수록 도 덕적 판단력이 낮아지는 것으로 분석되었다. 본 연구는 공인중개사의 윤리의식에 대하여 도덕적 판단력이라는 형태 로 계량화하였다는 점에서 그 간의 연구와 차별성이 있다. The moral judgments of real estate agents are important factors for professionals and social members carrying out real estate transactions. However, until now, neither the evaluation of the moral consciousness nor the research for its improvement have been sufficient. Therefore, this study examines the moral judgment and factors influencing that of real estate agent. The purpose of this paper is to provide an effective direction for raising moral awareness of real estate agents. This study was conducted by surveying real estate agents in Seoul in August 2017 using the Moral Competence Test(MCT), one of the measuring tools of morality. After multiple regression analysis of moral judgment into dependent variables, a negative correlation was found between moral judgment and the age of certified realtors. In addition, lower moral judgment was found in the low income group of respondents, and the moral judgment of simplified taxpayers was lower than that of the general taxpayer groups. However, this study has limitations as it fails to reflect many other factors that affect moral judgment.

뇌졸중 환자의 균형능력과 타이밍 기능평가의 신뢰도와 타당도

정승화 ( Jung Seung-hwa ),박대성 ( Park Dae-sung ) 대구대학교 특수교육재활과학연구소 2019 특수교육재활과학연구 Vol.58 No.2

본 연구의 목적은 뇌졸중 환자를 대상으로 청각적 피드백을 이용한 타이밍-기능적 움직임 능력과 균형 능력 사이의 상관관계를 알아보고 이를 통해 타이밍-기능적 움직임 평가도구 개발의 기초자료를 제공하고자 하였다. 뇌졸중 환자 30명을 대상으로 균형능력을 알아보기 위해 Function in sitting test, Berg balance scale, modified Postural assessment scale for stroke, 10 Meter walk test, Timed up & go를 실시하였고, 청지각 능력 평가와 균형능력 카테고리에 따른 네가지 타이밍-기능적 움직임 측정 방법을 실시하였다. 타이밍-기능적 움직임의 검사-재검사 신뢰도는 급간 내 상관계수(ICCs)를 이용하였다. 측정 변수들 간의 선형적인 연관성을 알아보기 위해 피어슨 상관계수를 나타내었다. 절대적 신뢰도는 측정오차의 정량화를 위해 표준 오차 측정(standard error of measurement; SEM)을 이용하였다. 연구결과 FIST점수와 벽면에 손 짚기는 유의한 음의 상관관계를 보였다(r=-.693, r=-.465, r=-.364). BBS점수와 발판에 발 올리기는 유의한 음의 상관관계를 보였다(r=-.511, r=-.492). mPASS점수와 발판에 발 올리기는 유의한 음의 상관관계를 보였다(r=-.463, r=-.500). 10MWT 값과 한 발짝 내딛기는 유의한 양의 상관관계를 보였다(r=.376, r=.369). TUG 값과 한 발짝 내딛기는 유의한 양의 상관관계를 보였다(r=.437, r=.471, r=.379). 네 가지 측정 방법 모두 ICC=.986 이상으로 높은 검사-재검사 신뢰도를 보였다. 버튼 누르기 방법과 벽 짚기 방법의 SEM은 측정한 평균값의 10%보다 작아 신뢰할 만한 수준이었다. 연구결과를 통해 세 가지 측정 방법 모두 균형능력과 높은 연관성이 있어 타이밍-기능 평가 도구로 활용이 가능 할 것이다. The previous studies have shown that the use of auditory feedback to improve balance ability and the improvement of upper limb ability of stroke patients through Rhythmic auditory stimulation using Interactivity metronome have been actively studied. However, there are insufficient studies to evaluate the patient's balance ability including control of lower extremity and trunk. Therefore, the purpose of this study is to provide basic data for the development of Timing-functional movement test tool to evaluate the balance ability of stroke patients. The design of this study was a cross sectional design, involving 30 patients with stroke. Timing-functional movement test-retest reliability was measured by intraclass correlation coefficients (ICCs) and Kappa values. The Pearson correlation coefficient was used to examine the linear relationship between measured variables. Absolute reliability was measured by standard error of measurement(SEM). Timing-functional movement test methods showed high test-retest reliability with ICC=.986 or better. The Function in sitting test and Wall touch was significantly negative correlated(r=-.693, r=-.465, r=-.364). The Berg balance scale and Step on the stool was significantly negative correlated(r=-.511, r=-.492). The modified Postural assessment scale for stroke and Step on the stool was significantly negative correlated(r=-.463, r=-.500). The 10 Meter walk test and One step in front was significantly positive correlated(r=.376, r=.369). The Timed up & go and One step in front was significantly positive correlated(r=.437, r=.471, r=.379). In this study, we investigated the clinical usefulness of Timing-functional movement using auditory feedback in evaluating the balance ability of stroke patients and found that it is useful for evaluating the balance ability of stroke patients with high reliability and validity.

앉은 자세에서 방석센서를 이용한 요통환자 골반가동성 측정의 신뢰도와 타당도

정승화 ( Seung-hwa Jung ),박대성 ( Dae-sung Park ) 대한물리의학회 2020 대한물리의학회지 Vol.15 No.2

PURPOSE: Postural and structural asymmetry due to muscle imbalances around the lower back and pelvis are the causes of back pain. Muscle imbalances in patients with chronic low back pain affect the pelvic tilt and movement, and it is necessary to assess the pelvic movement ability using the appropriate tools to determine the mediating effects of lower back pain. This paper reports the reliability and validity of the Sensbalance Therapy Cushion (STC) for pelvic movement and proprioception. METHODS: In this study, the Wii balance board (WBB) was used as a golden standard for pelvic movement measurements. FABQ, KODI, Myovision, and Pelvic movement were measured in 50 patients with chronic low back pain. The correlation between the lower-back muscle activity and pelvic movement was checked. The pelvic movement parameter was measured twice to determine the intra-rater reliability. RESULTS: The STC showed high test-retest reliability in the pelvic tilt measurements (ICC = .672 - .809). The testretest reliability of proprioception measurements (ICC = .588 - .859) and reaction time measurements (ICC = .542 - .836) were also high. The relationship between the WBB and STC showed a significant positive correlation with the pelvic tilt test (p < .01). The posterior pelvic tilt and lower-back muscle activity showed a significant negative correlation (p < .01). The pelvic left tilt and lower-back muscle activity showed a significant negative correlation (p < .05). CONCLUSION: The results revealed the high reliability and validity of the STC. Therefore, the STC can be used as an objective measuring device for evaluating pelvic tilt, proprioception, and reaction time in low back pain patients.

가이드노즐 형상에 따른 개수로용 횡류수차 성능연구

정승화(Seung-Hwa Jung),최영도(Young-Do Choi) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.춘계 No.-

그레이브스병 환자에서 항갑상선제가 지질과산화에 미치는 영향

정승화(Seung Hwa Jung),최용석(Yong Suk Choi),홍성표(Sung Pyo Hong),임성희(Sung Hee Ihm),최문기(Moon Gi Choi),유형준(Hyung Joon Yoo),박성우(Sung Woo Park) 대한내과학회 1995 대한내과학회지 Vol.48 No.5

Objectives: The development of a significant increase in metabolic rate and total oxygen consumption leads to an enhancement in oxygen stress, which results in an increased lipid peroxidation. The study was undertaken to evaluate: 1) the lipid peroxidative stress of subjects with hyperthyroidism related to changes in metabolic activity, 2) the influence of the antithyroid agent, propylthiouracil on the oxidative stress status of Graves disease patients. Methods: We studied thyroid function indices(T3, free T4 TSH) and lipid peroxidation in Graves disease patients, before and after treatment with propylthiouracil for three months. Results: It is revealed that red blood cell membrane lipid peroxidation is significantly correlated with thyroid function indices(T3 r=0.676, p<0.01, free T4 r=0.683, <0.05), before PTU treatment and lipid peroxidation is diminished in parallel with attainment of euthyroid state of thyroid activity after propylthiouracil administration, after PTU treatment. Conclusion: It is shown that lipid peroxidation that is attributed to oxygen consumption and oxidative stress are significantly correlated with the state of thyroid function in Graves' disease patients.

유입구 개방형 초저낙차 횡류수차의 성능

정승화(Seung-Hwa Jung),황영철(Yeong-Cheol Hwang),최영도(Young-Do Choi) 한국유체기계학회 2014 한국유체기계학회 학술대회 논문집 Vol.2014 No.11