Resistive switching characteristic of Ce0.9Y0.1O2/ TiO2 bi‑layer structure by photochemical metal‑organic deposition

Sung‑Eun Kim,Jin-Gyu Lee,In-Young Choi,Ha-Eun Kim,Hong-Sub Lee 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.1

Sneak current is one of the main bottlenecks for dense crossbar array resistive random access memory. This study reports highly non-linear resistive switching characteristic from Ce0.9Y0.1O2/ TiO2 bi-layer (1S/1R device) structure, fabricated by photochemical metal-organic deposition, as a solution for sneak current issue. Ce0.9Y0.1O2 material, possessing oxygen vacancies, was used as a potential barrier as well as oxygen reservoir which rectified the current of low resistance state without an electrical breakdown in 1S/1R device. TiO2 was adopted for resistive switching property, and TiO2 layer having mixed phase (anatase and brookite) showed typical diode switching behavior. The photochemical reaction of photochemical metal-organic deposition process and phase formation were monitored and established using by Fourier-transform infrared spectroscopy and X-ray diffraction, respectively. The 1S/1R device showed highly non-linear resistive switching characteristic, large on/ off ratio of above three orders of magnitude with low operating current.

HA 라우팅 기반의 개선된 멀티캐스트 제공 방안

김인경(In-Kyeong Kim),하정락(Jeong-Lak Ha),현은희(Eun-Hee Hyun),김상하(Sang-Ha Kim) 한국정보과학회 2001 한국정보과학회 학술발표논문집 Vol.28 No.2Ⅲ

IETF Mobile IP는 이동 컴퓨팅 환경에서 IP 멀티캐스트를 지원하기 위한 메커니즘으로 HA 기반 라우팅과 FA 기반 라우팅을 간략히 언급하고 있다. FA 기반 라우팅의 경우, 단말기 이동 시 멀티캐스트 트리를 재구성하는 오버헤드가 존재하는 단점이 있다. 반연, HA 기반 라우팅의 경우, 단말기 이동시 경로 최적화가 이루어지지 않는 단점에도 불구하고, 멀티캐스트 트리 수정에 대한 오버헤드가 존재하지 않은 장점이 있다. 이러한 장점은 망의 안정성을 높일 수 있기 때문에 많은 연구에서 HA 기반 라우팅을 채택하고 있다. 하지만, 기존의 HA 기반 라우팅 방법에서 가장 큰 장애 요소는 터널링 집중화 현상이며, 이를 해결하기 위해 Mobile Multicast(MOM) 등에서 정성적인 방법을 제안하고 있지만, 구체적인 프로토콜이 없으며 모든 HA들이 관여하는 복잡도로 인해 실제로 망에 배치되는 데 한계성을 가진다. 본 논문에서는 현재의 Mobile IP 메시지의 간단한 확장과 FA에 멀티캐스팅을 위한 기능을 첨가하여, 터널링 집중화 현상을 해결하는 프로토콜을 제안하고자 한다. 제안되는 프로토콜은 현재의 모든 IP 멀티캐스트를 수용하고, Mobile IP와의 호환성을 유지한다.

이동 환경에서 멀티캐스트 적용 방안

홍형섭(Hyung-Seop Hong),하정락(Jeoung-Lak Ha),현은희(Eun-Hee Hyun),김상하(Sang-Ha Kim) 한국정보과학회 2001 한국정보과학회 학술발표논문집 Vol.28 No.2Ⅲ

Mobile IP(MIP)[1] Working Group에서 제안하고 있는 멀티캐스트 적용 방안에는 크게 HA기반 라우팅과 FA기반 라우팅으로 구분된다. HA기반 라우팅 방법은 멀티캐스트 패킷을 HA에서 터널링하는 방법을 사용하므로 경로의 최적화가 이루어지지 않게 되며 터널 집중화 현상이 발생하게 된다. FA기반 라우팅 방법은 이동 호스트의 핸드오프가 일어날 때마다 멀티캐스트 트리의 재구성이 필요하므로 많은 오버헤드가 발생하지만 경로 최적화는 얻을 수 있다. 본 논문은 HA기반 라우팅과 FA기반 라우팅 방안을 절충한 새로운 멀티캐스트 제공 방안을 제안한다. MH의 이동이 빈번한 마이크로 레벨에서는 HA기반 라우팅을 이용하고, MH의 이동 거리가 큰 매크로 레벨에서는 경로 최적화를 위하여 새로운 멀티캐스트 트리를 재구성함으로써 보다 효율적 멀티캐스트 서비스가 가능한 메커니즘의 프로토타입을 제안한다.

우리 나라 보건관리대행서비스 평가 연구

하은희,조수헌,김선민,주영수,한상환,하미나,권호장,홍윤철,김창엽 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.1

Group occupational health service programme started in 1990 is one of the measures to cope with limited human and financial resources in occupational health. The programme has expanded rapidly to include 52 institutions, private as well as public, all over the country. In spite of its potential impact on health of employees and practice of occupational health in small and medium sized industries, comprehensive evaluation in terms of quality has not been tried. This study has aims to develop the criteria to assess the quality of newly developed group occupational health service programme, and to investigate the quality of institutions, and finally to develop policies for the quality improvement. 1) Criteria development : By defining occupational health services, in particular for small and medium sized industries, as one of the primary health care, followings are included as core elements of qualitative occupational health programme; accessibility, continuity, comprehensiveness, technical quality, intersectoral collaboration, emphasis on preventive services, community participation, and adequacy. Again each element is divided into five major components of national health system infrastructure developed by the World Health Organization; development of health resources, organized arrangement of resources, delivery of health care, economic support, and management. In turn, each component is categorized into three aspects of quality assessment, structure, process and outcome. Expert panel selected several criteria for each category to evaluate the programme. Criteria were modified according to each group of interviewees, to produce two sets of questionnaire, one for chief operating officer and another for nurses in the institutions, and the chief operating officer and workers in the workplace. 2) Subject : Of all 52 institutions, 25 voluntarily participated in the survey. At individual institution, chief operating officer and practicing nurses were interviewed in depth. After intensive education for interviewees, every interviewees, every interview was performed with standardized guideline and questionnaire. The quality of the 'Group occupational health service programme' was found to be lower than expected. Especially in continuity, comprehensiveness, technical quality, community participation and adequacy, lower quality in structural aspect was commonly identified throughout all the institutions,. Quality in terms of accessibility and continuity highly varied among institutions., To improve quality of the programme, more comprehensive and systematic programme such as accreditation has to be introduced. In addition, human resources, governmental fund and information systems for individual workers are to be developed. As a long range plan, integration of occupational health services into the national health systems and pooling of financial resources and planned allocation should be considered.

급성 연쇄상구균 감염후 사구체 신염에 동반된 고혈압 뇌증 1례

하태선,차상훈,이경은,엄정민 충북대학교 의과대학 충북대학교 의학연구소 1999 忠北醫大學術誌 Vol.9 No.2

고혈압성 뇌병증은 고혈압 환자에서 고혈압과 관련된 두통, 경련, 시각장애 및 다른 신경학적 장애를 동반하는 증후군이다. 증례는 13세 여자환아로 급성 연쇄상구균 감염후 사구체 신염에 동반된 고혈압성 뇌병증 환자였다. 내원시 혈압은 150/110 mmHg 였고 내원당시 검사소견상 단백뇨, 혈뇨, C3의 감소 소견을 보였다. 내원 2일째 자기공명영상을 시행하였고 스핀에코 T2 강조영상에서 양 후두엽과 후 측두엽에 고신호의 이상 부위들이 발견되었다. 치료후 실시한 자기공명영상은 정상 소견을 보였다. 본 저자들은 급성 사구체 신염 환자에서 자기공명영상으로 고혈압성 뇌병증을 진단하고 치료한 1례를 문헌고찰과 함께 보고하는 바이다. Hypertensive encephalopathy is a syndrome consisting of headache, seizures, visual changes, and other neurologic disturbances in patients with elevated systemic blood pressure. We experienced a 13-year-old girl who presented with the manifestations of hypertensive encephalopathy in acute post-streptococcal glomerulonephritis. She visited our hospital because of generalized tonic-clonic seizure after severe headache. On admission her blood pressure was 150/110 mmHg and initial laboratory findings revealed proteinuria, hematuria and decreased C3 level and, T2-weighted MR image showed increased T2 signal in both occipital lobes, suggesting cerebral edema. On follow-up MRI, pathologic lesions were improved. We described a case of hypertensive encephalopathy in acute post-streptococcal glomerulonephritis diagnosed by MRI with a brief review of some related literatures.

학업우수 초등학생 자녀를 둔 어머니의 진로지도 경험에 관한 질적 연구

하정,이항심,정혜윤,김은덕,유성경 한국직업능력개발원 2007 직업능력개발연구 Vol.10 No.3

본 연구는 학업우수 초등학생 자녀를 둔 어머니의 진로지도 경험을 한국의 사회·문화적 맥락에서 밝히고자 하였다. 이를 위해 서울지역에 살고 있는 초등학교 6학년인 학업우수아의 어머니 9명을 심층면담하고, 질적 연구 방법으로 분석하였다. 연구 결과, 107개의 개념과 44개의 하위 범주, 그리고 14개의 범주가 도출되었다. 어머니들의 진로지도 경험을 포괄하는 핵심범주로는 '자녀의 성취를 위해 자녀의 특성을 존중하고 자녀의 자율성을 키우면서 자신이 바람직하다고 여기는 방향으로 이끌어감'으로 밝혀졌다. 연구 결과를 바탕으로 학업우수 초등학생 자녀를 둔 어머니의 진로지도 경험의 실체를 논의하였으며, 부모를 대상으로 한 진로교육프로그램의 필요성과 후속 연구에 대한 제언을 하였다. This study examined the experience about career guidance of mother who has a academically talented child in Korea. Nine mothers were interviewed and the interview data were analyzed based on the Qualitative Research Method. Result has107 concepts, 44 subcategories and 14 categories. The core category is "The mothers consider their children's characteristics for the children's accomplishment and foster children's self-control and lead their children to desirable object the mothers view".Implications of the results and suggestions for future research are discussed.

p-형 Si(100) 기판 위에 성장시킨 Bi_(3.25)La_(0.75)Ti₃O_(12) (BLT) 박막의 전기적 특성

최은경,박문흠,김현주,하태곤,강민주,김상수 昌原大學校 基礎科學硏究所 2003 基礎科學硏究所論文集 Vol.15 No.-

Bi₃zsLa(0.75)Ti₃0_(12) (BLT) thin film have been grown on p-type Si(l00) substrates by a sol-gel spin coating process. The structure and surface morphology of the film were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEMI. Furthermore, the electrical properties were examined by capacitance-voltage ( C-V) characteristics by using a LF Impedance Analyzer(HP 4192A). XRD measurement show layered perovskite structure with a single phase in BLT thin film annealed at 700C for 30 min in oxygen. The measured grain size of BLT on Si is about 0.04 - 0.1 pn. From the cross-sectional SEM image, BLT film thickness is measured to be 0.4 pm. The C-V characteristic hysteresis curves show that the NIFS (metal-fexroelectric-semiconductor) structure has memory effect. The memory window decreases, with increasing frequency at MFS structure. And it is found that the memory window increases as the applied voltage to the ferroelectric capacitor is increased. These phenomena may be due to polarization reversals of the BLT ferroelectric film and because of the charge injection from Si substrate into the ferroelectric thin film. The results obtained indicate that the present BLT films are suitable for making ferroelectric field effect transistor(FeFET) memory.

방광의 이행상피암에서 p53과 PCNA 분포에 관한 연구

최은정,강상균,양승하,김대중,김의한 순천향의학연구소 1996 Journal of Soonchunhyang Medical Science Vol.2 No.2

Immunohistochemical studies were carried out to observe the expression of p53 protein and PCNA in transitional cell carcinoma (TCC), then analyzed according to the tumor grade and progression. 38 cases of TCC consist of 13 cases grade Ⅰ, 12 cases grade Ⅱ and 13 cases grade Ⅲ respectively. Results obtained are as follows. 1. p53 protein expression was seen in 60% of cases(15 out of 38 cases) In the poorly differentiated area and infiltrated lesion, tumor cell showed more strong positive reaction of p53 protein compared with well differentiated area. 2. All of 38 cases of TCC showed PCNA positive expression. The more strong positivity was seen in the poorly differentiated area and the more intense positive reaction was noted in the basal layer of the tumor nests. 3. The above results showed that positivity of p53 protein and PCNA are closely related with tumor cell differentiation(grade) and progression. It is concluded that positive reaction of p53 protein and PCNA may contribute to detection of tumor growth and prognosis of patient.

톡소포자충 배양시 약제투여에 따른 Toxoplasma P30 유전자의 발현

이상걸,이영하,김계영,나영언,신대환 충남대학교 의과대학 지역사회의학연구소 1996 충남의대잡지 Vol.23 No.2

To know the drugs effect on gene expression and its regulating mechanism by RT-PCR and southern blot hybridization assay based on detection of the P30 gene encoding the major surface antigen, P30 of Toxoplasma gondii and the DNA synthesis in T. gondii infected HeLa cells. The experiment was performed and the results were as follows. 1. The thymidine incooperation in DNA of HeLa cell and T. gondii infected HeLa cell reached peak level at 36 hours and suddenly decreased at 48 hours. The uracil incooperation in DNA of T. gondii reached peak level at 48 hours. 2. The decrease of P30 gene expression began from 24 hours after pyrimethamine treated and 36 hours after methotrexate treated in T. gondii. The results were some what different. Pyrimethamine was more sensitive and acted earlier to T. gondii than Methotrexate did. The decrease of P30 gene expression of T. gondii was regulated these drugs in dose dependent manner. 3. The effects of dibutyryl cyclic AMP on P30 gene expression increased peak at 24 hours and on contrary decreased at 60 hours after treatment in dose dependent manner, but at 10mM high concentration of dibutyryl cAMP, P30 gene expression was supressed. 4. Actinomycine D supressed the P30 gene expression of T. gondii in HeLa cell. As the results, we presume pyrimethamine acts more powerful and earlier to supresses P30 gene expression than methotrexate, and it is regulated at transcription level. The results of RT-PCR were in agreement with that of southern blot hybridization.

스포츠 유형과 신체적 자기개념과의 관계 연구

김상규,박은하 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

The purpose of this study was to examine the relationship of the type of sports to physical self-description. The subjects were 242 secondary school students from Gangweon province, who were engaged in 12 different types of sports including individual sports, individual contact sports, noncontact group sports, group contact sports, and noncontact sports. After a survey was conducted with Kim Byeong-jun(2001)'s Korean version of physical self-description inventory, the collected data were analyzed with SPSS program To look for connections between the types of sports and physical self-description, statistical data on mean and standard deviation were obtained, and then t-test was implemented. And one-way ANOVA was implemented to identify the influence of their gender, school grade and workout period. The findings of this study were as follows: 1. Among the individual sport players, the contact sport players had a better physical self-description than the noncontact sport players, but the difference between the two groups was insignificant, 2. In the field of the group sports, there was little gap in physical self-description between the contact sport players and noncontact sport players. 3. Regarding the effect of the individual and group sports on physical self-description, there was little gap between the individual and group sport players.