X-대역 SiGe HBT MMIC 차동형 전압 제어 발진기 개발

김보준,채규성,박민기,김창우 경희-다반 ASIC 설계교육센터 2005 경희-다반 ASIC센터 논문집 Vol.6 No.-

ISO 18000-6B, EPC Class-1 Gen-1, Gen-2 리더 표준에 적용되는 UHF 대역 RFID 리더용 RF 송신기를 하이브리드형 DHC로 설계 및 제작하였다. 송신기의 ASK 변조회로는 하나의 GaAs SPST스위치와 LPF로 구성하였으며, PR-ASK 변조 회로는 하나의 balua 두 개의 GaAs 통PST와 하나의 GaAs SPDT 스위치를 이용하여 link주파수 1-MHz 이상되는 변조신호에서 시간 지연이 없도록 설계하였다. LDMOS를 이용한 전력증폭기는 선형성을 위하여 8-dB back-off 상태로 동작시켜 출력전력 30-dBm을 얻었다.

엔진구동형 NiTi 파일의 근관성형능력 비교

김보혜,최경규,박상혁,최기운 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.2

The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using “single length”technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan’s test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time. 이 연구의 목적은 4가지 엔진구동형 NiTi 기구의 근관성형력을 비교하는 것이다. 32개의 투명레진모형을 사용하여 파일의 단면도가 S자 형태이고“single length”방법으로 근관성형을 시행하는 Mtwo와 crown-down 방법으로 근관성형을 하는 Profile, ProTaper Universal 및 K3로 근관성형을 하였다 (n = 8). 모든 근관은 한사람의 술자가 근단공 크기가 #30이 될때까지 성형하였다. 기구 사용 전과 후 근관 모양을 디지털 영상을 기록하였고, 컴퓨터 영상 분석 프로그램(Expression Scanner와 Adobe Photoshop CS)으로 평가하였다. 다음과 같은 결론을 얻었다. 근첨으로부터 1, 2, 3, 4, 5, 6, 7 mm 떨어진 부위의 내측과 외측으로 삭제된 레진 양을 측정하였고, 자료는 SPSS법으로 비교 분석하였다. 1. 근관형성 시간은 Mtwo가 84.50초로 가장 짧았으며, 총 작업시간은 K3가 269.37초로 가장 길었다(p < 0.05). 2. 기구의 변형과 파절은 모든 구동형 NiTi 파일에서 발생하지 않았다. 3. 근관 내측 폭경의 변화는 Profile이 1, 2 mm 부위를 제외한 다른 부위에서 가장 적었으며, ProTaper Universal은 모든 부위에서 가장 많았다(p < 0.05). 4. 근관 외측 폭경의 변화는 Mtwo이 1 mm 부위를 제외한 모든 부위에서 가장 적었으며, Profile은 3, 4 mm 부위에서 가장 많았다(p < 0.05). ProTaper Universal와 K3는 1, 2, 6, 7 mm 부위에서 가장 많았다(p < 0.05). 5. 근관중심변위율(centering ratio)은 Profile이 1, 4, 5, 6 mm 부위에서 가장 적었다(p < 0.05). 이상의 결과, 구동성 NiTi 파일을 이용한 만곡 근관의 근관형성은 치경부는 ProTaper와 같은 삭제력이 높은 파일을 사용하는 것이 근관 입구를 효과적으로 넓히고 더 나은 taper를 형성하며, 근단부는 Profile과 같은 근관 중심 변위가 적은 파일을 사용하는 것이 근관형성 시간을 단축하고 근단부의 근관 변형(transportation)을 줄일 수 있다고 판단된다.

쌍정 경계가 고온 초전도체 Y₁Ba₂Cu₃O단결정의 자기적특성에 미치는 영향

이보화,박정수,김채옥,김의훈,정규채 漢陽大學校 自然科學硏究所 1997 自然科學論文集 Vol.16 No.-

일반적으로 쌍정 경계(twin boundary)는 고온초전도체Y₁Ba₂Cu₃O??? 단결정 내에서 핀 고정점(pinning center)로 작용하여 단결정 시료의 자화에 영향을 미칠 것으로 알려져 왔다. 그러나 이에 대한 체계적인 실험적 연구가 수행되지 않고 있다. 본 실험에서는 Y₁Ba₂Cu₃O??? 단결정 시료를 성장시킨 후, 재 후열처리 과정 중에 단축 가압 방법(uniaxial stress method)을 이용하여 단결정 시료를 detwinning 하였다. 편광효과가 관측된 micro-Raman spectra와 X-ray 회절 패턴으로부터 관측된 (001)면의 주 피크의 2Θ 값을 통해서 단결정이 잘 성장되었음을 확인하였다. 그리고, 반자성 차폐 효과, 마이스너 효과 및 자기이력 측정 결과로부터 detwinning시간이 길어져서 쌍정 경계의 비율이 감소할수록 자화폭이 감소함을 관측하였다. 이로부터 자속 고정(flux pinning)이 줄어듦을 알 수 있었다. 그러므로 쌍정 경계가 고온초전도체 Y₁Ba₂Cu₃O??? 단결정의 핀 고정점으로 작용한다는 것을 알 수 있었다. Generally it is suggested that twin boundaries play the major role of the pinning center in high-Tc superconductor Y₁Ba₂Cu₃???? single crystal and influences the magnetization. However, any systematic experiment related with this expectation has not been performed yet. In this experiment, after growing Y₁Ba₂Cu₃??? single crystals, we detwinned them in oxygen atmosphere using uniaxial stress method while annealing them again. It was verified that single crystals had been grown well from micro-Raman spectra that showed the polarization effect and 2Θ values of (001) plain peaks in X-ray diffraction pattern. We observed that values of magnetization of samples decreased from antimagnetic shield effects, Meissner effect and magnetic hysteresis as detwinning time was increased and this result means that flux pinning decreases. As a result we confirmed that twin boundaries act as a pinning center in high-Tc superconductor Y₁Ba₂Cu₃??? single crystal.

새로운 isoquinoline 유도체, AQ44의 혈관평활근 수축에 미치는 영향

김보경,김윤선,용준환,장병준,박태규,조성일,장기철,이상목 한국노화학회 1998 한국노화학회지 Vol.8 No.3

소아의 변색된 치아에서 Vital Bleaching을 이용한 치료 증례

김보혜,손흥규,이종갑 大韓小兒齒科學會 1992 大韓小兒齒科學會誌 Vol.19 No.2

Discoloration of teeth, especially maxillary incisor, that appears in various types and severties causes a major problem in esthetic aspect. The attributing factors can be classified into extrinsic and intrinsic factors : chewing tabacco, coffee, and tea are some example of the former, and intake of tetracycline, fluorosis, pulpal necrosis, iatrogenic agents, systemic condition, genetic factors, and aging process are, the latter. Treatment of a discolored vital tooth include full crown restoration, direct or indirect venner restoration, vital bleaching, and so on. Several vital bleaching techniques have been developed since Capple first introduced a bleaching case using oxalic acid in 1877. Nowadays, the technique that utilizes both hydrogen peroxide and bleaching light is most preferred. The pulpal effect of vital bleaching medicaments and lights have been controversal, but it has been also noted that 98℉~141℉, 30~35% hydrogen peroxide causes only mild reversible inflammation. In these cases, 12 and 10-year-old sisters showed generalized brown discoloration of teeth. Their primary dentitions were normal color, and there were no history of discolored teeth. The exact cause could not be found, but tooth color was improved by vital bleaching of four times. For the better esthetic results, combination therapy of repeated bleaching and veneering restoration is recommended.

各級 學敎 學生들의 國家意識에 關한 硏究

李珪範,金均保,河在煥 釜山敎育大學 1973 부산교육대학 논문집 Vol.9 No.1

Educating the students so as to have a strong, racial and national consciousness is one of the essential aims of Korean education. The purpose of this study is to analyze, compare, and evaluate the degree how far the abovementioned aim has been achieved at the schools of various level, in order to get some useful materials an and certain directions for the educational planning. In this study, the national consciousness has been defined as the individual's cognitive and affective intention toward his own nation. Especially it has been regarded as a characteristic of actions having an emotional colour, the essence of which is the collective feeling. In terms of the fore-going conception, the writer has examined the internal structure of the national consciousness and, having devised the necessary tools, has measured the national consciousness of the students at the schools of various level. The samples for the investigation have been collected from the schools of each level in the various part of th nation. The results of this investigation can be summarized as follows. (1) The students of schools of lower grade have been found to have relatively higher national consciousness than those of schools of higher grade have. (2) As a whole, the national consciousness of female students is higher than that of male students. (3) The students of humanity and social science fields have higher national consciousness than those of science and technology fields have. (4) Generally the students of lower grade have shown the more affirmative and optimistic attitude toward their nation than those of schools of higher grade have shown. The national consciousness of the students is relatively decreasing in its degree as they advance to the schools of upper grade, which means that some serious problems are hidden in the the education of this aspect. And this means that while the racial and national consciousness has been continuously emphasized as a fundamental ideology in our national education, it has failed to grow to become a part of the students' inner life as they advance in their grade. And it can be said that we must analyze the above mentioned phenomena to discover the underlying meanings and reasons of those problems and must find out the most adequate educationl programs and methods to meet those problems.

구진상괴사성 결핵진 3례

손보성,송준영,정재봉,김병천,이상숙,류영욱,이규석 啓明大學校 醫科大學 1994 계명의대학술지 Vol.13 No.4

Papulonecrotic tuberculid is an eruption of necrotizing papules, particularly affecting the extremities and occurring in more or less symmetrical crops, and responding to antituberculosis therapy. Individual lesions heal with scarring. Histologically, vascular involvement is seen in early lesions. Late lesions are divided into two forms. In superficial forms, wedge shaped area of necrosis forms in epidermis and upper dermis. Epithelial and lymphoid cells gather around its periphery. In deep forms, with no epidermal change, granulomatous changes surrounded by well defined palisading histiocyte and lymphoid, epithelioid cells are seen. In mid-dermis and perivascular area, vessel shows vasculitis. In the first case, leukocytoclastic vasculitis and early granuloma formation were seen. In the second case, palisading granuloma formation was seen. In the third case, tuberculoid granuloma formation was seen. We report three cases of papulonecrotic tuberculid showing three different stages of histological finding, in individual cases.

아파트 내부공간에 대한 거주 후 평가 : 주공아파트 17평형을 대상으로 The 17 Pyung Size Housing Apartments Built in Korean National Housing Corporation

최보가,최무혁,박규정 경북대학교 1992 논문집 Vol.24 No.-

The purpose of this study is to make use of these materials for the next housing plan and to put emphasis on post occupancy evaluation. For this study, the apartments occupied are chosen and the degree of satisfaction with residence is examined, in real occupants' respect. As the objects, the apartments built by the Korean National Housing Corporation in 3 apartment sites of Taegu in 1979, 1983, 1985 is selected. The apartment size is restricted to 17 pyung. SPSS(Statistical Package for Social Sciences) is used as an analysis method and the degree of satisfaction is divided into 5 grade using Likert measurement to give objectivity. After the analysis, the degree of satisfaction with each apartment is compared and analyzed through Duncan's Multiple Test. The results are as follows. 1. In the satisfaction with each room, the degree of bathroom, kichen and dining room, balcony, entrance showed meaning difference. 2. Many factors out of evaluation factors showed meaning difference partly of room 1, room 2, room 3, kichen and dining room, bathroom utility room and boiler room, balcony in the degree of satisfaction with each apartment. 3. The improved factors, the factors which need to improve, the factors to which the occupants adapted themselves among evaluation factors are classified on the basis of standard satisfaction.

광중합 Glass lonomer Cement의 결합 강도에 대한 실험적 연구

김보혜,손흥규 大韓小兒齒科學會 1993 大韓小兒齒科學會誌 Vol.20 No.2

The purpose of study was to compare bond strength of Light-cured Glass Ionomer Cement with those of Chemically-cured Glass Ionomer Cement and Composite Resin to enamel and dentin surface. Each extracted molars, the buccal surfaces of which were flattened, were divided into two groups, so that 40 teeth their enamel exposed and the other 40 had their dentin exposed. The materials used were: 1) FujiⅡ LC(Light-cured Glass Ionomer Cement) 2) FujiⅡ&Shofu G.I typeⅡ(Chemically-cured Glass Iomomer Cement) 3) Silux Plus(Composite Resin) Each of the materials was applied to the exposed surface of 10 teeth by insertion into a cylindericalshaped matrix which is 3mm diameter and 2mm in height. The completed specimens were stored at 37。c under 100% humidity for 24 hours: then the shear bond strength of each material to enamel and dentin surface were measured with Instron universal testing machine. The following results were obtained: 1. Bond strength to enamel surface increased in order of Shofu G.I typeⅡ, FujiⅡ, FujiⅡLC, and Silux Plus. Statistical significance was obserbed except for Shofu G.I typeⅡ and FujiⅡ, which are chemically-cured materials(p<0.01). 2. Bond strenght to dentin surface increased in order of Shofu G.I typeⅡ, FujiⅡ, Silux Plus, FujiⅡLC. There was statistical significance(p<0.05). 3. Bond strength to enamel surface was greater than that to dentin. There was statistical significance(p<0.01). From such results, it can be concluded that when Glass Ionomer Cement is used for esthetic restoration, light-cured type, which has greater bond strenth to tooth structure, is preferred to chemically-cured type.

새 교육과정의 물리교과 분석 연구

한덕보,김규용 濟州大學校 師範大學 科學敎育硏究所 1989 科學敎育 Vol.6 No.-

The new curriculum that is revised will be put into effect in 1990. The pur-pose of this thesis is to find out a desirable direction of physics education by ab-stracting the problem and suggesting the way of improvement through analyzing the contents of the physics curriculum in high school. The conclusion of this thesis is as follows ; 1 . The teacher should be encouraged to present his teaching with 15 percent of a class for experiment, and in this thesis I think that all the subjects, espe-cially technology and society, should be taught in connection with science. 2 . The completion unit of physics has been decreased together with the suc-cessive revision of curriculum. In the fifth curriculum, the time allotment of physics curriculum is also less than that of the 0th- curricula of science. 3 . There is no difference between the new textbook and the old textbook in contents. It is desirable that the contents of the new textbook should be remade up, with a view to closing connection with practical life, in many categories.