Temperature-dependent Hall Measurement of AlGaN/GaN Heterostructures on Si Substrates

이인학,김용현,장영준,신종훈,T. Jang,장승엽 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.1

For AlGaN/GaN high electron mobility transistor (HEMT) devices grown on Si substrates, westudied the influence of the surface defect density on the Hall mobility and the carrier concentration. We established a Hall measurement system over wide temperature range (8 800 K) by combininga closed-cycle refrigerator and a heating chamber. The two-dimensional electron gas (2DEG) inthe epitaxially-grown AlGaN/GaN HEMT structures showed high mobilities, i.e., > 1500 cm2/Vsat 300 K and > 7000 cm2/Vs at 8 K. As the surface defect density increased, the mobility valuesat 8 K decreased due to scattering from charged impurities at low temperatures. However, at hightemperatures where optical phonons are a major source of scattering, the mobilities do not showa significant dependence on the surface defect density. In addition, the carrier density showed anunexpected decrease at temperatures above 300 K, which is ascribed to a change in the misfit strainupon heating.

미래사회에 대비한 학교교육개혁에 관한 연구 : 초등학교 교육을 중심으로

李麟鶴 대구보건대학 1995 대구보건대학 論文集 Vol.15 No.-

우리 교육의 장래는 우리 교육체제를 둘러싸고 있는 사회의 변화와 긴밀히 관련되어 다변, 다원화 사회에 능동적으로 대처하기 위한 교육정책개혁을 실시하는데 달려 있다. 다가오는 21세기 미래사회는 첨단산업분야에서의 급격한 기술혁신으로 자원 에너지절약적인 기술, 정보산업의 가속화로 가정, 사회, 기업의 업무에서도 자동화, 기계화, 가속화하게 되고, 국가간의 관계가 정치, 경제, 사회, 문화 등 제반 영역에서 상호 의존적 성격이 강하게 나타나는 개방, 국제화 사회가 될 것이다. 한편 산업구조가 다변화되고 사회구성원의 요구 및 가치관 둥이 다양해지는 다변 다원화 사회가 될 것으로 전망된다. 본 연구는 이러한 21세기의 사회변화에 능동적으로 대처하기 위한 우리의 학교교육개혁 방안을 초등학교교육을 중심으로 검토하고자 했다. 교육이 변화해야 한다는 것은 누구나 공감하고 있는 사실이다. 무엇보다도 중요한 것은 교실현장의 주체인 교사자신의 의식구조 변화가 필요하고 국가경쟁력을 갖추기 위하여 다양한 정보화 능력, 다원적 사고, 주체적 대응능력, 전문적 지식 및 기술의 보유, 국제적 사회적 감각과 시각 등을 갖추어야 할 것이다. 특히, 21세기 이후의 미래사회를 책임질 2세 국민교육을 담당하고 있는 초등교육이야 말로 중등이후의 교육은 물론 국가 장래를 좌우하는 기초 교육임을 누구도 부인할 수 없을 것이다. 따라서 양적 충원에 급급하던 지금까지의 초등교원 정책으로는 21세기의 미래교육에 효율적으로 대응할 수 없음은 당연하다. 초등교원의 전문성이 존중되고 학교현장의 자율성이 중시되는 전문적 공동체로서의 교직사회를 활성화하는 것이 절실히 요구되고 있다. 폭발적으로 증가하는 지식량을 효과적으로 수용하고, 미래산업사회에서 나타나게 될 비인간화현상을 극복하면서 전인적 인간양성이 가능하도록 교육내용을 전반적으로 구조화하여 재구성할 필요가 있다. 교육과정 운영의 개선과 함께 교육환경 및 여건 개선도 교육효과를 제고하기 위해 시급한 실정이다. 다가오는 미래사회에 폭증하게 될 지식량을 학교가 효과적으로 학생들에게 전달하기 위해서는 교수-학습방법의 개선과 함께 이를 구현하도록 하기 위한 기본적인 외곽시설 및 내부시설이 확보되어야 하며 가정과 사회환경도 오늘의 문제를 현실적으로 점차적으로 수정해 나가야 할 것이다.

시각장애 학교의 컴퓨터 및 관련 공학 기자재의 활용 실태 분석 및 개선방안

이인학 韓國視覺障碍硏究會 1998 시각장애연구 Vol.14 No.-

가정방문 물리치료의 필요성 및 요구하는 서비스의 특성

이인학,김용건,권춘숙,한동욱 대한물리치료학회 1999 대한물리치료학회지 Vol.11 No.2

This study was performed to investigate the degree of demand and general features of services required of home visiting physical therapy for chronic ill patients. The study subjects were ambulatory and admitted patients treated with physical therapy at six general and one oriental hospitals, one welfare center, four health centers located in Taejon from March 2, 1999 to March 16. Authors developed structured questionnaire, and distributed it to each physical therapist of study organizations. Total number of distributed questionnaire was 500, and 405 questionnaire were collected and analysed finally. 1. 82.4% of patients and 90.0% of caregivers are showed that home visiting physical therapy was needed(P$lt;0.05) 2. The rate of necessity for home visiting physical therapy by kinds of disease was 94.9% in cerebral palsy, 95.0% in upper spinal cord injury, 83.3% in lower spinal cord injury, 84.5% in cerebral vascular accident, 89.6% in traumatic brain injury, 83.5% in other diseases. 3. In the general features of required service for home visiting physical therapy, 33.7% of patients and 34.4% of caregivers want special isolated physical therapy center, 33.1% of patients and 43.3% of caregivers want 3 times per week in frequency, 46.7% of patients and 45.0% of caregivers want 30-60minutes in treatment duration, and 48.0% of patients and 46.7% of caregivers want more intensive care than general hospitals. 4. In the working place of home visiting physical therapy, 36.1% of patients and 36.2% of caregivers wants physical therapist worked in general hospital. Also, 53.3% of Patients and 52.2% of caregivers answered no interested in physical therapist's gender. The most preferential age of home visiting physical therapist is thirties in 43.2% of patients and 63.4% in caregivers

교육적 가치의 준거로서 J. Dewey의 반성적 사고 : 아동교육론을 중심으로 with special emphasis on the education of children

이인학 한국아동교육학회 2003 아동교육 Vol.12 No.2

This dissertation examines a suggestion for our education to develop children's thinking faculty with the intention of meeting the changing society actively and how Dewey's reflective thought is reflected in a standard of educational value with a scientific method for understanding a changing and developing world toward the viewpoint of children, purpose and contents of education. This study is in several questions as follows. First, what is the character of a reflective thought which J. Dewey's educational idea has? Second, how is Dewey's reflective thought reflected in an educational theory? Third, what are suggestions for thinking power of children influencing Dewey's reflective educational theory? This dissertation has studied how to realize Dewey's reflective thought through preceding research and bibliographical analysis home and abroad. The point of Dewey's educational philosophy is experience. Man's growth and development have completed through experience. Man's thinking ability is an important element of growth and development. Though we have experienced routines every day, we expect them to change best in quality when they have been proceeded by a reflective thought. A reflective thought is not a principle of educational method but a principle of education as a standard of educational value. It is based on an educational philosophy for the cultivation of thinking power and reflective thought. Dewey's educational theory based on the reflective thought is influencing the education of children as follows. First, children have to learn a practical knowledge which is utilized through a thinking faculty and be given a variety of routine actions through the sequence between social life and school life. Second, the goal of education should be settled in the process of education with an emphasis on the cultivation of children's thinking faculty. Third, the contents of education should be presented the methods to develop children's thinking ability and help induce their thought and thinking process concerning their experience. Fourth, the teachers should have the technique of teaching with several materials, affluent knowledge and activates. And it is necessary to teach their students for the cultivation of children's thinking power.

장애인의 치료만족도에 따른 지역 사회중심재활에 관한 연구

이인학,김미란,박래준 대한물리치료학회 1998 대한물리치료학회지 Vol.10 No.2

A questionaire was conducted to obtain care satisfactions in information of the 325 disabled persons among the total 9,314 handicapped people in Taejon area, and was surveyed during the period of June 1 to August 31, 1997. The results are as follows: 1. Among the studied disabled persons, 54.5% of male, and 45.5% of female. 2. Before disabled in occupation, 32.0% of out of work group were high, 6.5% of farm, student group were low. Before disabled in occupation by gender, male group is 29.9% of out of work group were high, 0.6% of housework group were low. female group is 34:5% of out of work group were high; 4.7% of student group were low(P$lt;0.001). 3. After disabled in occupation, 75.1% of out of work group were high, 10.8% of in working group were low. After disabled in occupation by gender, male group is 87.6% of out of work group were high, 1.7% of housework group were low. female group is 60.1% of out 4f work group were high, 10.8% of in working group were low(P$lt;0.001). 4. Medical security status, 64.9% of medical aid group were high, 35.1% of medical insurance group were low. Medical security status by gender, male group is 71.2% of medical aid group were high, 28.8% of medical

점진적 저항운동과 수중운포로그램이 여성노인의 하지근력강화와 균형능력에 미치는 영향

이인학,문성기,이병권,이정우,김인섭 대한임상전기생리학회 2004 대한임상전기생리학회지 Vol.2 No.1

원주 만종리 절골 유적 - 원주 호저면 만종리(산130번지 일원)○○부대 이전사업부지 내 유적 -

이인학 중부고고학회 2019 중부고고학회 학술대회논문집 Vol.2019 No.3

일부 도시 재가 지체장애인의 치료실태

이인학,문성기,김미란,Lee, In-Hak,Moon, Sung-Gi,Kim, Mi-Ran 대한물리치료과학회 1997 대한물리치료과학회지 Vol.4 No.2

To find out the actual status of treatment of physically handicapped who were stayed of home, 320 physically handicapped persons were selected among total 6,264 physically handicapped registered in Taejon city, surveyed from January 1st to March 30, 1997. Following are the results ana lysed of collected data from 201 samped persons. 1. For the cause of physically handicapped, 36.3% was congenital, 26.9% was cerebralvascular acciednt(CVA). and 14.9% was infectious diseases and others in that orders. The must frequest cause of below 20 years age group was congenital cause, but that of $20{\sim}30$ years age group and $40{\sim}50$ years age group were accident and CVA repectively. 30.0% of respondents caused by infection and others earned household living expenses. Household living expenses were higher among the respondents caused by congenital cause but those were lowest in the accidental couse group. Handicap durations were longer in the accidental cause group and infections and others group than the congenital cause group and CVA group. 2. 54.7% of studied handicapped were under treatment. But 36.3% of them were stopped treatment, and 8.9 % of them answered not treated. Most handicapped, coused by congenital and CAV, were under treatment, but most of them caused by accidental and others were stopped treatment. 3. For the medical facilities, 54.5% of them utilized welfare facility, but 25.5% utilized general hospital and 20.0% of them utilized oriental medical hospital and health centers. Congenital cause group frequently selected welfare facility for the treatment facility. But accidental cause group frequently seleced general hospitals and CVA gruop frequently selected oriental medical hospital and others. The medical cost of welfare facility, oriental medical hospitals and others were lower than that of general hospitals. 4. The proportions of under treatment were higher among yonger age higher monthly living expenses group shorter handicapped duration groups, congenital cause group and handicap grade II group. But that of stop treatment were higher among congenital cause group, infectious and others cause group, and handicap grade I & then III group. 5. For the feelings satisfacion about medical treatment, only 35.3% of under treated group responed satisfation. 55.5% of them responded so-so, but 9.1 % responed dissatisfaction. The proportion of satisfaction was higher among shorter handicap duration group.

Proton-Induced Conductivity Enhancement in AlGaN/GaN HEMT Devices

이인학,이철,최병기,윤예슬,장영준,장승엽 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.8

We investigated the influence of proton irradiation on the AlGaN/GaN high-electron-mobility transistor (HEMT) devices. Unlike previous studies on the degradation behavior upon proton irradiation, we observed improvements in their electrical conductivity and carrier concentration of up to 25% for the optimal condition. As we increased the proton dose, the carrier concentration and the mobility showed a gradual increase and decrease, respectively. From the photoluminescence measurements, we observed a reduction in the near-band-edge peak of GaN (~ 366 nm), which correlate on the observed electrical properties. However, neither the Raman nor the X-ray diffraction analysis showed any changes, implying a negligible influence of protons on the crystal structures. We demonstrated that high-energy proton irradiation could be utilized to modify the transport properties of HEMT devices without damaging their crystal structures.