Microstructure, Tensile and Fatigue Properties of Al–5 wt.%Mg Alloy Manufactured by Twin Roll Strip Casting

Joon‑Young Heo,Min‑Seok Baek,Kwang‑Jun Euh,Kee‑Ahn Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.5

This study investigated the microstructure, tensile and fatigue properties of Al–5 wt.%Mg alloy manufactured by twin rollstrip casting. Strips cast as a fabricated (F) specimen and a specimen heat treated (O) at 400 °C/5 h were produced andcompared. In the F specimen, microstructural observation discovered clustered precipitates in the center area, while in theO specimen precipitates were relatively more evenly distributed. Al, Al 6 (Mn, Fe), Mg 2 Al 3 and Mg 2 Si phases were observed. However, most of the Mg 2 Al 3 phase in the heat-treated O specimen was dissolved. A room temperature tensile test measuredyield strength of 177.7 MPa, ultimate tensile strength of 286.1 MPa and elongation of 11.1% in the F specimen and167.7 MPa (YS), 301.5 MPa (UTS) and 24.6% (EL) in the O specimen. A high cycle fatigue test measured a fatigue limit of145 MPa in the F specimen and 165 MPa in the O specimen, and the O specimen achieved greater fatigue properties in allfatigue stress conditions. The tensile and fatigue fracture surfaces of the above-mentioned specimens were observed, and thisstudy attempted to investigate the tensile and fatigue deformation behavior of strip cast Al–5 wt.%Mg based on the fi ndings.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

국내 영․유아 발달 선별 및 진단 검사도구에 대한 고찰 : 표준화중인 검사도구들을 중심으로

이준석,조광순 한국특수교육문제연구소 2004 특수교육저널 : 이론과 실천 Vol.5 No.1

본 연구에서는 영·유아의 전반적인 발달특성을 확인하여 발달지체 정도를 알아볼 수 있도록 돕는 발달검사도구를 선별검사와 진단검사로 나누어 개념 및 특성을 고찰하고, 국내에서 표준화가 되었거나 표준화가 실시되고 있는 발달검사도구들을 분석하여 특성 및 문제점, 향후 방향에 대해 알아보았다. 연구결과 국내에서 발달선별검사들은 활발히 표준화되고 있으나 심리측정학적인 측면에서 다양한 자료제시와 추후연구가 필요한 것으로 나타났다. 이에 비해 발달진단검사들은 극히 제한적으로 표준화 연구가 이루어지고 있는 것으로 나타났다. 많은 도구들이 타당도에 있어 문제가 나타나고 있으며, 발달검사의 표준화에는 장애영·유아를 포함시키는 것이 필요하고, 감각장애나 신체장애를 지닌 영·유아들을 고려하여 검사를 제작하거나 표준화할 필요가 있는 것으로 나타났다. 특히 0-2세 영아들을 위한 발달검사도구 개발은 좀더 활발히 이루어져야 하는 것으로 나타났다. The purpose of this study was to introduce definitions and characteristics of developmental screening and assessment for young children, to identify characteristics and limitations of norm-referenced developmental tests in Korea, and to suggest future directions. It was found that various developmental screening tests are being standardized; However, most tests demonstrated limited phychometric data, and follow-up investigation is needed to improve the reliability and validity of the tests. With regard to the developmental assessment tests, it was found that few tests are being standardized. Further research is needed to confirm the validity of the items and procedures for both screening and assessment tests. It is suggested that young children with disabilities need to be included in standardization. It is also suggested that specific test procedures need to be developed for children with hearing and visual impairments. Futhermore, developmental tests for infants and toddlers are needed due to the limited numbers of tests available in Korea.

『万葉集』の時代的背景

崔光準 新羅大學校 1998 論文集 Vol.46 No.-

万葉集은 日本이 자랑하는 가장 오래된 歌集이다. 이 歌集을 올바로 이해하기 위해서는 우선 노래되어졌던 그 시대의 배경을 알지 않으면 안된다. 이것을 문학의 風土라고 말한다. 600년경부터 노래되어져 759년까지 불리워졌던 万葉集의 바른 이해를 위하여 그 시대의 역사적ㆍ시대적ㆍ문화적 배경은 매우 중요하다. 1기 이전부터의 역사적ㆍ시대적배경을 살펴보면 4기의 万葉集이 만들어 지기까지 우리 고대의 渡來人들의 역할이 눈에 띄게 보이는 것을 알 수가 있다. 日本의 고대국가의 형성에서 부터 문학적 역할에 이르기 까지 우리 조상들의 깊은 숨결을 느낄 수 있다. 3세기부터 백제의 멸망에 따른 渡來人들은 日本문화형성에 매우 큰 역할을 완수했다. 万葉集도 이와같은 渡來人들의 존재에서부터 편찬된 것을 확인할 수 있었다.

대처執權期 英國社會福祉서비스의 變容

박광준 新羅大學校 1991 論文集 Vol.32 No.1

The election of the Conservative government in 1979 marked a turing point in the history of social security and of the British welfare state in general. It was to attempt a major restructuring of the welfare system. The purpose of this study is to examine changes in the social services and social security during the Thatcher administration 1979-1990. And the study is divided into two parts. Part 1 of the study, this paper, deals with the changes in the field of social services. In this part, the privatisation policy in housing and health care are concentrately and critically examined. For the more explicit comprehension of Thatcherism, differences in social welfare policies since 1945 between two political parties, the Conservative and the labour, and the process of the break-up of Post War concensus, and meaning and characteristics of Thatcherism are reviewed. Part 2 of the study, for the next paper is to deals with the contents of Green Paper and White Paper 1985. Social Security Reform of 1986. The efects of the Thatcher Revolution would be also included. Privatisation of the social services include the shedding of work from public services to private contractors, the encouragement of private sector competition with public services, the sale of public assets to private owners ar artificially low prices, and polices for securing a larger share of the costs of public services from their users. In the field of health services, since 1979 Thatcher Government has been the encouragement of private medical care. And patient charge for NHS services is sharply increased. For example, the prescription charge has increased by 590% in the period of 1979-1985. Privatisation of housing services is mainly focused on owner-occupation. Government spending on housing has been reduced abslutely and relatively. As a consequence of such policy, those groups most disadvantaged by these developments in housing policy further marginalized, socially and politically, in a residual and minority tenure. Those groups benefiting from these have become incorporated into a property owning democracy which promotes and rewards individualism and self-reliance in all spheres, deprecates state intervention, and stigmatises welfare recipients.

위법성착오에 대한 비교법적 연구

지광준,박상진 강남대학교 사회과학연구소 2001 사회과학논총 Vol.12 No.-

Gd₂O₃doped CeO₂에서의 Al₂O₃ 및 Ga₂O₃의 고용도한

최광훈,이주신 경성대학교 공학기술연구소 2002 공학기술연구지 Vol.9 No.-

The solid solubility limits of Al_2O_3 and Ga_2O_3 in Gd_2O_3 doped CeO_2 were determined by X-ray diffraction and scanning electron microscope measurements. The solubility limit of Al_2O_3 in Gd_2O_3 doped CeO_2 was found to be 2 mol%, and Ga_2O_3 was found to be 5 mol%. It is expected that the determination of the solid solubility limits will give an important information in a study on the promotion of the sintering properties with sintering aids addition.

유도 전동기를 위한 자기 동조 퍼지 제어기 설계

전광호,하남수,박준열,김상윤 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.2

The conventional PI control, that are used in the control loop for outer speed of the induction motor, also has difficulty dealing with the dynamic speed tracking, parameter variation, and the load disturbance. As a result, the motion control system operates with a poor performance in the motor´s low speed range. In this paper, a novel speed control system that implements the fuzzy logic controller(FLC) is proposed. The proposed FLC used the speed error, its rate of change, and the drive current as three fuzzy variables. The real command output current is chosen by the defuzzification of the fuzzy output extracted from the fuzzy control rules. The flux and the torque of the induction motor are estimated using the dynamic model with an excellent dynamic response over a wide speed range and with the rotor flux field-oriented scheme of the decoupling characteristics. The performance of this control system is substantiated by computer simulations.

순·구개열 환자와 정상 소아의 두개안면 형태에 관한 비교 연구

고광준,김영주,조수범 大韓口腔顎顔面 放射線學會 1995 Imaging Science in Dentistry Vol.25 No.2

The purpose of this study was to determine whether any difference existed in craniofacial morphology between cleft children and normal subjects. Thirty three measurements of the various regions of cranium and face were obtained from lateral cephalometric radiograms in 40 cleft children(27 males, 13 females) and 40 normal subjects(23 males, 17 females) in our dental hospital from Jan. 1988 to Dec. 1995. The measurements were compared with those in control subjects who had no history of craniofacial abnormalities. The obtained results were as follows: 1. In the cranium, the cleft children had significantly shorter posterior cranial base length(S-Ba) and total anterior-posterior cranial base length(N-Ba) (P<0.05). 2. In the upper face, the cleft children had significantly shorter upper anterior facial height(N-ANS) and upper posterior facial height(Ptm'-SNL)(P<0.05). 3. In the lower face, the cleft children had significantly shorter anterior-posterior mandibular length(Pog-Ar) and anterior-posterior mandibular body length(Pog-Go)(P<0.05)> 4. In the facial profile, the cleft children had significantly shorter total facial height(N-Me) and posterior facial height(S-Go)(P<0.05).

페루프 운전 복권형 하이브리드 스테핑 전동기의 토오크 리플에 미치는 Lead Angle의 영향

우광준,유정봉,김규희 단국대학교 1997 論文集 Vol.31 No.-

In this paper, we estimate the influence on torque ripple in the closed-loop drives of 2 phase bifilar-wound hybrid stepping motors by lead angle control method. We propose an instantaneous phase current equation which is the function of lead angle with respect to motor speed and motor time constant. We show that torque ripple rate is greatly reduced by the optimal lead anglecontrol method from the computer simulation results.