Step Free Energy Change and Microstructural Development in BaTiO₃-SiO₂

Chang, Jaem Yung,Kang, Suk Joong L. Trans Tech Publications, Ltd. 2007 Key Engineering Materials Vol.352 No.-

<P>The effect of step free energy on the grain growth behavior in a liquid matrix is studied in a model system BaTiO3-SiO2. BaTiO3-10SiO2 (mole %) powder compacts were sintered at 1280°C under various oxygen partial pressures (PO2), 0.2, ~ 10-17 and ~ 10-24 atm. As the step free energy decreases with the reduction of PO2, it was possible to observe the change in growth behavior with the reduction of the step free energy. At PO2 = 0.2 atm, essentially no grain growth (stagnant grain growth) occurred during sintering up to 50 h. At PO2 ≈ 10-17 atm, abnormal grain growth followed stagnant grain growth during extended sintering (incubation of abnormal grain growth). At PO2 ≈ 10-24 atm, normal grain growth occurred. These changes in growth behavior with PO2 and the step free energy reduction are explained in terms of the change in the critical driving force for appreciable growth relative to the maximum driving force for grain growth. The present experimental results provide an example of microstructure control in solid-liquid two- phase systems via step free energy change.</P>

Biomechanical analysis of lumbar decompression surgery in relation to degenerative changes in the lumbar spine – Validated finite element analysis

Li, Quan You,Kim, Ho-Joong,Son, Juhyun,Kang, Kyoung-Tak,Chang, Bong-Soon,Lee, Choon-Ki,Seok, Hyun Sik,Yeom, Jin S. Elsevier 2017 Computers in biology and medicine Vol.89 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>There are no studies about the biomechanical analysis of lumbar decompression surgery in relation to degenerative changes of the lumbar spine. Therefore, the purpose of this study was to compare, by using finite element (FE) analysis, the biomechanical changes of the lumbar spine in terms of annulus stress and nucleus pressure after two different kinds of lumbar decompression surgery in relation to disc degenerative changes.</P> <P><B>Methods</B></P> <P>The validated intact and degenerated FE models (L2-5) were used in this study. In these two models, two different decompression surgical scenarios at L3-4, including conventional laminectomy (ConLa) and the spinous process osteotomy (SpinO), were simulated. Therefore, a total of six models were simulated. Under preloading, 7.5 Nm moments of flexion, extension, lateral bending, and torsion were imposed. In each model, the maximal von Mises stress on the annulus fibrosus and nucleus pressure at the index segment (L3-4) and adjacent segments (L2-3 and L4-5) were analyzed.</P> <P><B>Results</B></P> <P>The ConLa model and disc degeneration model demonstrated a larger annulus stress at the decompression level (L3-4) under all four moments than were seen in the SpinO model and healthy disc model, respectively. Therefore, the ConLa model with moderate disc degeneration showed the highest annulus stress at the decompression level (L3-4). However, the percent change of annulus stress at L3-4 from the intact model to the matched decompression model was less in the moderate disc degeneration model than in the healthy disc model.</P> <P><B>Conclusions</B></P> <P>Although the ConLa model with moderate disc degeneration showed the highest annulus stress, the degenerative models would be less influenced by the decompression technique.</P>

몰리브덴 퍼어말로이의 자기저항 효과에 관한 연구

장충근,유중렬,송재용,윤만영,박재형,손대락 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

자기저항센서를 제작하기 위하여 Mo-permalloy(Ni:79.43%, Fe:14.47%, Mo:5.7%, Mn:0.38%, C:0.013%)를 슬라이드 그라스에 진공증착하여 sensor element를 제작한 후 포화자속밀도(B_(s)), 보자력(H_(c)), 자기이방성상수(K//), 자기저항변화율(ΔR/R)을 조사하였다. 진공증착된 permalloy 박막의 포화자속밀도는 0.746T 이었으며, 자화주파수 1kHz에서 보자력은 2.90A/cm(//),1.98A/cm(⊥) 이었고, 열처리 후에 1.79A/cm(//). 1.37A/cm(⊥)로 감소되었다. 한편 이 소자의 자기이방성상수는 1.38X10^(4)erg/cm^(3) 이었으며 5x1^(0-3)T의 자장변화에 대만 저항변화율(ΔR/R)은 2.0% 이었다. 앞으로 이 소자의 온도특성, 잡음특성 및 내열성 등을 조사하고자 한다. To fabricate magnetoresistive sensor, Mo-permalloy(Ni:79.43%, Fe:14.47%, Mo:5.7%, Mn:0.38%, C:0.013%) was evaporated on the slide glass. Saturation magnetic induction(B_(s)), coercive field strength(H_(a)), magnetic anisotropy constant(K), and magnetoresistance were measured for the fabricated samples. The evaporated samples show that saturation magnetic induction was 0.746T, and coercive field strengthes were 2,90A/cm(//) and 1.98A/cm(⊥), and this values were reduced to 1.79A/cm(//) and 1.37A/cm(⊥) respectively after annealing. For the measurement of coercive field strength, magnetizing frequency of 1kHz was used. For the fabricated sensor element, magnetic anisotropic constant was 1.38X10^(4)erg/cm^(3) and magneto-resistance change(ΔR/R) was 2.0% under the magnetic field change of 5X10^(-3)T, We will continue study on the characteristics for the temperature, heat resistance, and noise.

일본의 국제화와 정치체제의 변화

장달중 서울대학교 국제지역원 2000 국제지역연구 Vol.9 No.3

본 논문의 목적은 탈냉전과 글로벌리즘의 확산에 따른 일본 정치체제의 변화를 분석하고 예측하는데 있다. 냉전의 종결로 자본주의와 사회주의의 이데올로기적 대립축이 소멸된 일본의 정치는 보-혁대결을 특징으로 했던 "1955년 체제"가 해체되고 정당간의 이합 집산을 통한 연립 정치가 계속 되고 있다. 냉전의 종식과 글로벌리즘의 확산은 지금까지의 이익유도적 일본의 정치에 세 가지의 선택을 요구하고 있다. 그 첫째는 신 보수주의의 흐름이며, 둘째는 관료 주도의 테크노크라트 정치흐름이며, 셋째는 리버럴 정치의 선택이다. 글로벌리즘의 확산에 따른 사회 경제적 변화는 새로운 유권자와 새로운 정치지도자들을 만들어 내고 있으며 이에 따라 일본의 정치는 재편될 것으로 예측되어 왔다. 그러나 지난 10년 간의 정치적 실험은 사회 경제적 변화와 정치개혁 간의 지체현상을 그대로 노정시켰다. 이와 같은 지체 현상은 당분간 지속될 것으로 보이며, 이 때문에 신 보수주의의 민족주의적 정치흐름이나 서구적 리버럴 정치 흐름의 가능성은 상당히 낮아 보인다. 대신 일본사회의 안정성을 해치지 않는 범위 내에서의 국제화를 수용하는 이른바 타협성의 관료주도적 보수 정치가 당분간 지속될 것으로 보인다. The purpose of this paper is to analyze the Impact upon Japan's political system of the collapse of the cold war confrontation and the spread of globalism. The immediate impact of the collapse of the cold war structure was the dissolution of the so-called "1955 system" which was characterized by the ideological confrontation between progressives and conservatives and the beginning of the coalition politics. The Japanese political system seems to be faced with three system choices. First, it is a neo-conservative political system. The second choice is a bureaucrat-led technocratic political system. The third is a liberal one. It is beyond doubt that the impact of globalism and IT revolution are reaching far beyond economy by creating new interest groups, constituents and new political leaders. It will certainly strike at the core of the Japanese political system which survived by co-opting political interest groups that arose as the economy and society modernized. But Japan shows a lag between socio-economic change and political change. While IT generation does not have its political channel, old generation is trying its utmost efforts to protect its vested interests in association with conservative political forces. Thus, Japan would be very slow in embracing the globalization impact upon its political system. The outcome would be a compromise system in which conservative elite keeps power by allowing only a limited globalization impact in order to preserve social solidarity.

한국·미국·스페인 청소년의 태권도 수련이 인성교육에 미치는 영향

유창재,양정옥,이중숙,이상돈,김영수,조만태 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.6

The purpose of this study was to analyzed what effect Taekwondo training has upon Juvenile trainees in Korea, America, and Spain. to see if there is a significant difference in their Human nature Education. The subject of this study was set up as 547 Juvenile trainees who are including 183 Koreans, 185 Americans and 179 Spanish people belonging to gymnasia in their own countries, and sampling by purpose sampling. The means in this study is used to amend and complemented after confirming suitability of the contents in the questionnaire that is made on the basis of questionnaire Lee Chul Ho(1996). it is used as study means after modified, whether the substance of question is right in fitness and applicability or not, Reliability of the question, the range of Cronbach's a is showed from .7924 to .8450. The method of statistically analysis adapted one-way ANOVA, two-way ANOVA by using SPSS WIN 10.0 Program. The result of this study are as followed : First, it can be seen that American Juvenile and Spanish Juvenile show more significant change than Korean Juvenile in their Human nature Education by the Taekwondo training according to their nationality. Second, it can be seen that Juvenile who have had the Taekwondo training for more than from three to five year show more significant change in their emotion, sociability and attitude towards life than those who have had the same training for more than other period in their Human nature Education according to their Taekwondo training period. Third, as a result of analytic investigation of what effect the same training has upon the change factors in their Human nature Education in accordance with their training period and nationality, it can be seen that the training itself and nationality has the greater influence on them than the training period. Therefore, judging from the above findings, it can be proved that the Taekwondo training has much more significant and positive effect on Juvenile in their change of emotion, sociability and attitude towards life.

결핵성 척추염에서 양측 접근법에 의한 전방척추융합술의 수술적치험 1예

강중식,조준,윤승환,문창택,장상근 건국대학교 의과학연구소 2001 건국의과학학술지 Vol.11 No.-

In the treatment of tuberculous spondylitis, posterior spinal fusion is more simple and safe procedures than anterior spinal fusion. We performed bilateral anterior spinal fusion with autologous iliac bone graft and concomitant with psoas muscle abscess drainage and antituberculosis drug. As a result, patient was possible early ambulation and he had no recurrence, no complication such as resorption of bone fragment and kyphotic angle change. This article describeds the advantage of bilateral anterior approach in tuberculous spondylitis wish psoas abscess.

월경전 기분 변화와 출산후 불안-우울 증상간의 상관성

한창수,김용구,이낙우,김 탁,김해중,김 현,조숙행 대한생물치료정신의학회 2001 생물치료정신의학 Vol.7 No.1

To investigate the relationship between premenstrual mood changes and anxiety, and mood symptoms in the perinatal period , questionaire survey was carried out. There was no significant correlation between premenstrual symptom scale value and Edinburgh postpartum depression scale value. And theme was no relationship between premenstrual symptom scale value and state anxiety inventory scale value in the perinatal period. This findings suggest that premenstrual mood changes are not directly correlated with mood changes in the perinatal period.

주의력 결핍 아동의 행동변화를 위한 원예·압화 프로그램 구성과 실험설계 연구

최중옥,김주창 한국특수아동학회 2002 특수아동교육연구 Vol.4 No.2

본 연구는 원예ㆍ압화 프로그램이 ADHD 아동의 주의력 결핍 행동의 향상에 미치는 효과를 규명해 보기 위한 프로그램 구성과 실험설계를 연구하는데 그 목적을 두고 있다. 본 연구의 대상은 일반학급에 재학중인 아동 가운데 DSM-Ⅳ의 주의력 결핍 과잉행동 장애 진단준거, ADHD-SC-4(ADHD Symptom Checklist-4) 범주 A 항목 검사결과 주의력 결핍증후군 심각도 점수(Symptom Severity Scores)에서 주의력 T≥59, 중도이상의 심각도 점수를 나타내는 아동 3명을 대상으로 선정한다. 실험설계는 ABAB 연구설계를 적용한 20회기의 원예ㆍ압화 프로그램을 실시하는 가운데 석 달반동안 관찰될 것이다. 그리고 관측행동 자료는 ADHD 아동의 주의력 결핍행동의 주요 특성인 선택적 주의력의 결핍, 지속적 주의력의 결핍, 주의력 조절능력의 결핍 등을 중심으로 통계적으로 뿐아니라 임상적으로 분석될 것이다. 본 연구는 교육현장에서 학생들의 주요한 기초학습기능인 주의력의 향상을 위하여 원예 및 압화활동을 활용한 프로그램을 제시한 것으로 현장교사나 부모들의 특수교육 프로그램 개발이나 실행에 시사점을 줄 것으로 본다. The purpose of this study is to examine the effect of the Horticulture & Pressed flower Program on the improvement of attention deficit behavior of ADHD children. The subjects of this study are the children in general education classes whose Symptom Severity Scores are T≥59, that is higher than average, based on the result from the test of DSM-IV, ADHD-Symptom Checklist 4, Item A, which is a diagnosis standard of attention deficit behavior. Among the 2nd grade students in Elementary School A in Busan, 3 children of ADHD will be observed for three and half months, with 20 times of the Horticulture & Pressed flower Program applied under ABAB design. And the data of observed behavior will be analyzed statistically and clinically on the point of three major characteristics of ADHD children's attention deficit behavior, which are the lacking of selective attention, the lacking of constant attention, and the lacking of attention adjustment ability. The recommendation for further study is as follows; First, A study on the influencing on change of ADHD by developing Horticulture & Pressed flower Program. Second, Not only ABAB research design, but also other research design will be needed to study Horticulture & Pressed flower Program for ADHD. Third, A study on the Horticulture Therapy Program for handicapped family.

우리나라 병원의 마케팅 활동수준과 재무성과

한창훈 ( Chang Hoon Han ),김원중 ( Won Joong Kim ) 한국병원경영학회 1999 병원경영학회지 Vol.4 No.2

The main objective oh this paper is to perform an empirical analysis on the relationship between various marketing activities and financial performance of Korean hospitals. A survey was conducted through structured questionnaire for 495 hospitals, and data from 218 hospitals were utilized in the final analysis. (response rate : 44%) Survey items include general characteristics of the hospitals (size, type, location), degree of competition, financial performance, marketing organization/ budget, and level of various marketing activities in service development, access improvement, promotion, and pricing. We examine descriptive statistics of the response scores on marketing activities to evaluate the current status of marketing management of Korean hospitals, compare the results across hospital size, type and location, and perform regression analysis to investigate the relationship between marketing and financial performance. Major findings are as follows : 1) About 46% of the responding hospitals gave marketing departments although they are named as 'planning' or 'PR' departments, and the marketing budget on average represents 1.74% of the total expenditures. 2) Average level of marketing activities is calculated to be about 3.32 on 5-point scale, meaning that Korean hospitals implement their marketing programs 'somewhat actively'; however, the scores on the areas of marketing planning and strategy are relatively low. 3) Large hospitals tend to be more active in marketing than small hospitals, and public hospitals' activities in marketing are not lower compared to private hospitals. 4) Level of overall marketing activities is positively related with financial performance measured by various financial indicators except for profitability, implying that marketing is successful in revenue generation but needs to be more cost-effective. Also, when the marketing variables are separately included in the regression, no significant relationship is found, which means that various marketing activities are more effective when they are collectively implemented.

비후성심근증의 임상적 관찰

전상중(Sang Joong Jeon),정진홍(Jin Hong Chung),홍경순(Kyung Soon Hong),전재은(Jae Eun Jun),박의현(Wee Hyun Park),박희명(Hi Myung Park),김윤년(Yoon Nyun Kim),김권배(Kwon Bae Kim),장성국(Sung Kug Chang),이종주(Jong Joo Lee) 대한내과학회 1987 대한내과학회지 Vol.33 No.4

N/A The clinical and laboratory features of hypertrophic cardiomyopathy were studied in 30 cases. They consisted of 21 males and 9 females, and the age ranged from 21 to 74 years with an average of 50. The cardinal presenting symptoms were dyspnea, chest pain and palpitation in the order of decreasing frequency. Physical examination revealed apical systolic murmur in 27 cjases (90%), with thrill in 10 (33%), and the routine chest films showed enlargment of cardiac silhouette in 15 cases (50%). Abnormal electrocardiographic findings are noted in 27 cases (90%). Among them repolarization abormalities and left ventricular hypertrophy were the most common, occurring in 71% and 66 % of the cases, respectively, follower1 by left atrial enlargment in 24% and the abnormal Q waves in 20% Among various echocardiographic abnormalities, the mean of septal thickness and its ratio to left ventricular posterior wall thickness were 19 mm and 2,1 respectively, and the mean of the degree of systolic anterior motion of mitral valves was 9 mm. The mean of preejection period and left ventricular ejection time as well as their ratio determined in 10 cases were within normal limits. Out of 20 eases treated with beta or calcium blockers. for a mean of 22 months, 14 (70) experienccd symptomatic improvement. □ (5%) deteriorated and in the remainder (25%) there were no noticeable changes.