불소계 플라즈마에 노출된 YAG 세라믹스의 식각거동 및 XPS 분석

김경범,김대민,이정기,오윤석,김형태,김형순,이성민,Kim, Kyeong-Beom,Kim, Dae-Min,Lee, Jung-Ki,Oh, Yoon-Suk,Kim, Hyung-Tae,Kim, Hyung-Sun,Lee, Sung-Min 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.5

Chemical composition and status of chemical bonding of the YAG($Y_3Al_5O_{12}$) ceramics after the exposure to fluorine plasma have been investigated using X-ray photoelectron spectroscopy, with the analysis on its erosion behavior. On the surface, F showed the maximum content, decreasing with depth, meanwhile the cation composition remained almost constant, irrespective of the position. The peaks due to Y in the reaction layer consisted of two kinds, showing the Y-O and Y-F bonds. These surface modifications under fluorine plasma seem to promote the erosion of the YAG ceramics. Excess addition of $Al_2O_3$ or $Y_2O_3$ into stoichiometric YAG produced 2nd phases of $Al_2O_3$ and $YAlO_3$, respectively, resulting in the slight difference in the local erosion rates. But, the overall average erosion rate was not sensitive to such excess additions of $Al_2O_3$ or $Y_2O_3$.

정보보안 ; 특집 / 분산 객체 컴퓨팅의 정보 보호 기술

김경범,최락만,송영기,인소란 한국정보처리학회 1997 정보처리학회지 Vol.4 No.2

N/A N/A

압전 캔틸레버 스프링 구조물(SPCS)의 에너지 하베스팅 특성

김경범,김창일,정영훈,이영진,조정호,백종후,남산,성태현,Kim, Kyoung-Bum,Kim, Chang-Il,Jeong, Young-Hun,Lee, Young-Jin,Cho, Jeong-Ho,Paik, Jong-Hoo,Nahm, Sahn,Seong, Tae-Hyeon 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.10

Spring supported piezoelectric cantilever structures (SPCS) were fabricated for vibration-based energy harvester application. We selected four elastic springs (A, B, C, and D type) as cantilever's supporter, each elastic spring has a different spring constant (S). The C type of SPCS ($S_C$: 4,649 N/m) showed a extremely low resonance frequency of 81 Hz along with the highest power output of 38.5 mW while the A type of SPCS ($S_A$: 40,629 N/m) didn't show a resonance frequency while. Therefore, it is considered that the lower spring constant lead to a lower resonance frequency of the SPCS. In addition, a tip mass (18 g) at one end of the SPCS could further reduce the resonance frequency without heavy degradation of power output.

태양전지용 결정질 실리콘 웨이퍼에서의 레일리기준 기반 레이저산란의 광편향 분석에 관한 연구

김경범,Kim, Gyung-Bum 한국반도체디스플레이기술학회 2010 반도체디스플레이기술학회지 Vol.9 No.4

In this paper, optical deflection of laser scattering has been investigated based on Rayleigh criterion for crystalline silicon wafer in solar cell. A laser scattering mechanism is newly designed using light scattering properties in silicon wafer. Intensity distributions of laser scattering are different, depending on the incident angle of laser computed from Rayleigh criterion. In case of the incident angle satisfied with the criterion, they are asymmetric. Also, their specular reflection angle is shifted to unpredicted ones. These phenomena are in accordance with previous theories of laser scattering. The optical deflection of laser scattering is experimentally identified with the designed laser scattering mechanism. Its mathematical model is presented from the geometric relationship of laser scattering. It is shown that the optical deflection of laser scattering agree with the presented model, exclusive of grazing angles which is satisfied with Rayleigh criterion.

열증착법으로 성장된 ZnO 나노구조물의 산소유량 변화에 대한 성장 변화

김경범,장용호,김창일,정영훈,이영진,조정호,백종후,남산,Kim, Kyoung-Bum,Jang, Yong-Ho,Kim, Chang-Il,Jeong, Young-Hun,Lee, Young-Jin,Jo, Jeong-Ho,Paik, Jong-Hoo,Nahm, Sahn 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.10

ZnO nanostructures were developed on a Si (100) substrate from powder mixture of ZnO and 5 mol% Pd (ZP-5) as reactants by ${\times}$ sccm oxygen pressures(x= 0, 10, 20, 40). DTA (differential thermal analysis) result shows the Pd(5 mol%)+ZnO mixtured powder(PZ-5) is easily evaporated than pure ZnO powder. The PZ-5 mixtured powder was characterized by DTA to determine the thermal decomposition which was found to be at $800^{\circ}C$, $1,100^{\circ}C$. Weight loss(%) and ICP (inductively coupled plasma) analysis reveal that Zn vaporization is decreased by increased oxygen pressures from the PZ-5 at $1,100^{\circ}C$ for 30 mins. Needle-like ZnO nanostructures array developed from 10 sccm oxygen pressure, was well aligned vertically on the Si substrate at $1,100^{\circ}C$ for 30 mins. The lengths of the Needle-like ZnO nanostructures is about 2 ${\mu}m$ with diameters of about 65 nm. The developed ZnO nanostructures exhibited growth direction along [001] with defect-free high crystallinity. It is considered that Zn vaporization is responsible for the growth of Needle-like ZnO nanostructures by controlling the oxygen pressures. The photoluminescence spectra of ZnO nanostructures exhibited stronger 376.7 nm NBE (near band-edge emission) peak and 529.3 nm DLE (deep level energy) peak.

천안 천흥사지 발굴조사 출토 고려시대 평기와 분석

김경범 한국중세고고학회 2023 한국중세고고학 Vol.- No.14

이 글은 충청남도 천안시 서북구 성거읍 천흥리 190-2번지 일원에 위치한 천흥사지 1~2차 발굴조사 보고서를 중심으로 먼저 1차 발굴조사 출토 통일신라말~고려전기에 해당하는 평기와 97점을 비롯하여 2차 발굴조사 출토 평기와 46점 등 총 143점을 대상으로 먼저 양식적 속성인 문양분류를 통한 평기와의 통계를 알아본 후, 계량적(크기) 속성+제작기술적(평기와 내·외면에 남아있는 제작기법 및 특징) 속성을 검토하고자 한다. 이러한 분석결과를 통해 평기와의 시대적 변화 양상을 파악하고자 하였다. 마지막으로 이러한 평기와 분석을 통해 천흥사지의 창건 및 중심연대도 검토해 보고자 한다. 천흥사지 1~2차 발굴조사를 통해 출토된 평기와 분석 결과, 천흥사의 창건은 태조13년(930)에 천안부(天安府)로 하고 도독(都督)을 두었다고 기록된 10세기 전반으로 여겨진다. 금번 천흥사지 중심사역 내에서 2차례 발굴조사된 유적에서 출토된 평기와 분석을 통해 천흥사지 기와 본연의 성격과 선대 유구의 상한을 추정한 점은 향후 천흥사지에 대한 연차적인 발굴조사나 연구의 기초적인 기준을 마련했다는 점에서 그 의의를 찾을 수 있겠다. This paper was written focusing on the first and second excavation reports of Cheonheungsa Temple Site located at 190-2 Cheonheung-ri, Seonggeo-eup, Cheonan-si, Chungcheongnam-do. First of all, there are statistics on plain roof-tiles through pattern classification, which is a stylistic attribute, for a total of 143 pieces, including 97 plain roof-tiles from the end of Unified Silla to the early Goryeo Dynasty excavated in the first excavation and 46 plain roof-tiles excavated in the second excavation. And then examines quantitative(size) and manufacturing techniques and characteristics(manufacturing techniques and features remaining on the inside and outside of the plain roof-tiles). Through these analysis results, we tried to understand the changes of the period of the plain roof-tiles. Finally, through this plain roof-tiles analysis, I would like to examine the foundation and central period of Cheonheungsa Temple Site. As a result of the analysis of the plain roof-tiles excavated through the first and second excavations of Cheonheungsa Temple site, it is believed that the foundation of Cheonheungsa Temple was in the earlier half of the 10th century in the 13th year of Taejo(930), when it was recorded Cheonanbu(天安府) and Dodok(都督) were placed. Through the analysis of the plain roof-tiles excavated from the ruins of Cheonheungsa Temple Site twice, I estimated the original nature of the roof-tiles of Cheonheungsa Temple Site and the upper limit of the remains. This is significant in that it has established the basic standards for annual excavation and research on the Cheonheungsa Temple Site in the future.

신생아에서 용질배설에 관한 연구

김경범,박재현,최병민,이현희,윤재균 관동대학교 의과학연구소 2000 關東醫大學術誌 Vol.4 No.1

Purpose : Determination of urinary concentration in neonate is mandatory for precise management of fluid and electrolyte requirements. Although measurement of urine specific gravity has been proposed far monitoring fluid requirements, the reliability of specific gravity does not accurately predict urine osmolalities in the neonate period. So specific gravity should be checked by measuring the osmolality. Also the urinary excretion of creatinine has been used for the assessment of hydration state. We present the result of specific gravity, urine osmolality, urine creatinine in a spot urine sample during the first week of life as a reliable reference standard. Methods : Spontaneously-voided urine sample were obtained in 40 full term neonates. Two urine samples were available with a interval of 4 to 7days (A: 1st day, B: 4 - 7days), Urine sample was tested for specific gravity with a strip test. Also urinary osmolality, urinary creatinine, urinary creatinine/osmolality ratio were measured. Results : The mean of specific gravity tested by the strip test was 1.006±0.0040 (A) , 1.005±0.0036 (B). The mean of urine osmolality and creatinine were 177.7 ± 103.0 and 30.9±21.6 (A), 145.7 ±90.3 and 26.4± 17.7 (B). The mean of excretion rate of urine creatinine/osmolality ratio was 18.2 ±8.5 (A), 19.4 ±9.1 (B). There was correlation between urine specific gravity and osmolality in neonate(r=0.833(A), 0.842(B) p<0.001). Urinary creatinine/osmolality levels of the first urine samples were closely correlated with the second samples (r=0.617, p<0.001). Conclusion : Specific gravity of urine was enough to predict the osmolality in neonate. But Specific gravity should be checked by measuring the osmolality of urine. Urine osmolality and creatinine were spread over a wider range and did not used to urinary excretion of solute in neonate. Urinary creatinine/osmolality ratio can be used to standadise the urinary excretion on solute in the first week of life.

노벨라(Novela, novella)의 의미 변천과 단편소설 장르의 형성

김경범 한국중세근세영문학회 2003 중세르네상스 영문학 Vol.11 No.1

Los trminos Novella y Novela: la transicin semntica y la formacin del gnero

수열합성에 의한 c축 배향 ZnO 나노로드 배열의 성장과 구조, 광학적 특성

김경범,김창일,정영훈,이영진,백종후,Kim, Kyoung-Bum,Kim, Chang-Il,Jeong, Young-Hun,Lee, Young-Jin,Paik, Jong-Hoo 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.3

ZnO nanorods array have been grown on the seed crystal coated Si(100) substrate by hydrothermal method. The growth, structural and optical properties of ZnO nanorods array were investigated with a variation of precursor concentration from 0.01 M to 0.04 M. The array density of grown ZnO nanorods per same area was increased with increasing the concentration of precursor solution. Vertically aligned ZnO nanorods with hexagonal wurtzite structure have highly preferred c-axis orientation along (002) lattice plane. Especially, ZnO nanorods array developed from 0.04 M precursor solution showed a diameter of about 85 nm and length of 1.2 {\mu}m$ without any crystallographic defects. The photoluminescence spectra of ZnO nanorods from heavier precursor concentration exhibited stronger UV emission around 380 nm corresponding with near-band-edge emission.

수정합성공정에 의한 무연 (1-x)BaTiO3-x(Bi0.5Na0.5)TiO3 (0.01≤x≤0.10) 세라믹의 PTCR 특성 연구

김경범,김창일,이영진,백종후,이우영,김대준,정영훈 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.12

(1-x)BaTiO3-x(Bi0.5Na0.5)TiO3 (0.01≤x≤0.10) ceramics were fabricated with muffled sintering by a modified synthesis process. Their positive temperature coefficient of resistivity (PTCR)characteristics were investigated systematically. All specimen showed a perovskite structure with a tetragonal symmetry. Both the lattice parameter of a and c axes were slightly decreased with increasing (Bi0.5Na0.5)TiO3 (BNT) content. Grain growth was achieved when the incorporated BNT was increased to 6 mol% and the inhibition of grain growth is considered to be due to the appearance of Ba vacancy (V"Ba) in the (1-x)BaTiO3-x(Bi0.5Na0.5)TiO3 (0.08≤x). With 4 mol% BNT addition, room temperature resistivity decreased to 48 Ω·㎝ and a resistivity jump (ρmax/ρmin) was as high as 1.1×104, respectively. Curie temperature was also increased to 171oC with increasing BNT content.