• 대한치과교정학회지
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• 제10권1호
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• pp.81-93
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• 1980

The interrelationships between growth rates (and size) of the selected cranifacial dimensions and body dimensions (height and weight) were investigated in the longitudinal data of primary school children from 6 to 11 years of age. The data were obtained from serial cephalometric radiographs and health record which were taken at one year interval. Regression analyses were used to analyze the data. The main concludions might be summarized as follows; 1. Size relationships between body height (and weigh) and S-Gn, posterior facial height (s-Go), total mandibular length (Ar-Gn) showed high significant correlation, but no association between body height, weight and anterior cranial base length (S-N). 2. Correlation coefficients between facial dimensions and body height (and weight) were getting lower with age increase. 3. At all age groups, significant prediction equation for some facial dimensions with body height and weight were obtained. 4. In this sample, the growth rates of facial dimensions and body height and weight showed almostly constant during this age period and the growth rate of body height and weight of girls was exceeded that of boys. 5. A relatively high degree of variation between individuals existed in the sample. 6. A positive correlation was found for the relationship between the growth rates of facial dimensions and those of body height (and weight) in boys and girls, but was not found in total samples.

• 동굴
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• 제34권35호
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• pp.32-42
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• 1993

The Paektu-san mountains are geographically situated in the Korea strait to the north of the main peninsula, coordinated between the longitudes of W(127$^{\circ}$15'~128$^{\circ}$00')and E(128$^{\circ}$15'~129$^{\circ}$00'), and between the latitudes of S(41$^{\circ}$15'~42$^{\circ}$00') and N(42$^{\circ}$10'~42$^{\circ}$40'). The volcanic group of the Paektu-san mountains can be devided into 2 main kinds of volcanos by the method investigation, The ashes are mainly made of tremolite, trachte, basalt and pumice, or, a little quartz, labradorite and volcanic glass. These sorts, ratios and forms of the rocks are respectively similar. The Haeven lake is surrounded by 19 peaks. The central volcanic cone is a secant cone in shape, with an altitude of the 1800m to 2749,2m (Chang-kun-bong), an average diameter of 10km, and a shape of an ellipse seen high from the plane. They say there were several eruptions in 1668, 1700 and 1702 A. D. The crystal structure of the rock sample collected at the cave of Mt. Paektu-san is monoclinic. The quantitative analysis of the rock samples in the cave is done by using XRF this time. The chemical compositions by XRF fundamamental parameter analysis is : SiO$_2$: 50.72Wt%, TiO = 2.422Wt%, $Al_2$O$_3$= 17.65Wt%, Fe$_2$O$_3$= 9.371Wt%, CaO = 8.711Wt%, MgO = 4.l19Wt%, MnO = 0.l15Wt%, $K_2$O = 1.369Wt%, Na$_2$O : 3.028Wt% and P$_2$O$_{5}$ = 0.365Wt%. The K-Ar age of the rock sample is also determined to be 0.16Ma. This paper describes some problems experienced in dating young volcanic rocks, and then discusses chemical compositions, X-ray fluorescence analyses and the age of the formation of a lava tunnel such as in Mt. Paektu-san.n.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.331-334
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• 2003

Photovoltaics is considered as one of the most promising new energy technology, because its energy source is omni present, pollution-free and inexhaustive. It is agreed that these solar cells must be thin film type because thin film process is cost-efficive in the fact that it uses much less raw materials and can be continuous. The defect chalcopyrite material $CuIn_3Se_5$ has been identified as playing an essential role in efficient photovoltaic action in $CuInSe_2$-based devicesm It has been reported to be of n-type conductivity, forming a p-n junction with its p-type counterpart $CuInSe_2$. Because the most efficient cells consist of the $Cu(In,Ga)Se_2$ quarternary, knowledge of some physical properties of the Ga-containing defect chalcopyrite $Cu(In,Ga)_3Se_5$ may help us better understand the junction phenomena in such devices.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.863-866
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• 2003

Multi-walled carbon nanotubes (CNTs) were synthesized on glass substrates in the different ramp-up heating ambient of vacuum, He, Ar, and $N_{2}$ by thermal chemical vapor deposition. CNTs with higher crystallinity were developed in the buffer gases with faster growth rates than in vacuum. Field emission characteristics were strongly related to the relative position of CNT emitters to the cathode electrodes. The areal-spread emission and instability were overcome by locating the emitters far away from the edges of cathode electrodes. The electrical conditioning of emitters improved their emission uniformity over a large area although it decreased the emission current. This study also discussed the long-term stability of CNT emitters.

• 대한치과교정학회지
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• 제27권6호
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• pp.963-978
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• 1997

교정 환자들은 성장과 발육을 하는 개체이므로 교정치료의 시기 선택은 가장 어렵고 중요한 요소이며, 측모두부방사선 사진의 개발에 따라 안면 성장의 양상과 연령 증가에 따른 성장 변화량은 성장 예측 등의 교정적 분야에 유용하게 이용되어왔다. 이에 3세에서 12세까지의 한국인 남여 아동 각 연령군에서의 두개 안면부의 경조직 계측치 평균과 신장, 체중과의 연관성을 파악하고자 하였다. 교정치료를 받은적이 없고, 성장과 발육에 장애가 없는 3세에서 12세까지의 소년 147명과 소녀 106명을 연구대상으로 만 2년간 두부방사선 사진을 채득하여 경조직 분석을 Burstone의 COGS논문에 기초하여 두개저, 상악골과 하악골, 수직 계측, 수평 계측, 상하악 기저골 관계 및 치성 계측의 6개 부분으로 나누어 성장과의 관계 및 키와 몸무게와의 관계를 연구한 바 다음과 같은 결론을 얻었다. 1. 두개저 계측에서 N-Ar(FH), N-Ba(FH)의 최대 성장 증가량은 남녀 모두 체중과 신장의 최대 증가량을 나타내는 연령과 일치한다. 그 외의 항목은 일정 증가 양상을 보이고 있으나 큰 증가를 보이지 않고 있어 두개저의 성장은 초기에 거의 완성됨을 알 수 있었다. 2. Genial angle은 남녀 모두에서 성장과 함께 점차 감소하였다. 3. ANS-Me(L)보다 N-ANS(L)가 더 많은 성장량을 보여 안면 형태에 많은 영향을 줌을 알 수 있었다. 4. $N-A-Pog^{\circ}$ 은 연령증가와 더불어 감소하며 이는 하악골의 성장이 상악골의 성장량보다 빠르고 많았다. 5. 상하악 기저골 관계에서 Y-axis의 길이는 증가하지만 각도는 일정하게 유지되어 하악골은 두개저에 대해 일정방향으로 성장하였다. 6. 영구치 맹출과 더불어 Interincisal angle은 감소하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.163-163
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• 2000

In this research, we used the ion irradiation technique which has an advantae in improving intentionally the properties of surface and interface in a non-equilibrium, instead of the conventional annealing method which has been known to improve the material properties in the equilibrium stat. Cu/Co multilayered films were prepared on SiN4/SiO2/Si substrates by the electron-beam evaporation for the Co layers and the thermal evaporation for the Cu layers in a high vacuum. The ion irradiation with a 80keV Ar+ was carried out at various ion doses in a high vacuum. Hysteresis loops of the films were investigated by magneto-optical polar Kerr spectroscopy at various experimental conditions. The change of atomic structure of the films before and after the ion irradiation was studied by glancing angle x-ray diffraction, and the intermixing between Co and Cu sublayers was confirmed by Rutherford backscattering spectroscopy. The surface roughness and magneto-resistance were measured by atomic force microscopy and with a four-point probe system, respectively. During the magneto-resistance measurement, we changed temperature and the direction of magnetization. From the results of experiments, we found that the change at the interfaces of the Cu/Co multilayered film induced by ion irradiation cause the change of magnetic properties. According to the change in hysteresis loop, the surface inplane component of magnetic easy axis was isotropic before the ion irradiation, but became anisotropic upon irradiation. It was confirmed that this change influences the axial behavior of magneto-resistance. Especially, the magneto-resistance varied in accordance with an external magnetic field and the direction of current, which means that magneto-resistance also shows the uniaxial behavior.

• 한국전기전자재료학회논문지
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• 제17권5호
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• pp.467-475
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• 2004

ZnO epilayer were synthesized by the pulsed laser deposition(PLD) process on $Al_2$ $O_3$substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193 nm) excimer laser. The epilayers of ZnO were achieved on sapphire(A $l_2$ $O_3$) substrate at a temperature of 400 $^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are 8.27${\times}$$10^{16}$$cm^{-3}$ and 299 $\textrm{cm}^2$/Vㆍs at 293 K, respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}$(T)= 3.3973 eV - (2.69 ${\times}$ 10$_{-4}$ eV/K) $T^2$(T＋463k). After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Zn}$ , $V_{o}$ , Z $n_{int}$, and $O_{int}$ obtained by PL measurements were classified as a donors or accepters type. In addition, we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in ZnO/A $l_2$ $O_3$did not form the native defects because vacuum in ZnO thin films existed in the form of stable bonds.s.s.s.

• 전자공학회논문지A
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• 제30A권7호
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• pp.60-74
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• 1993

Experiments of RIE of tungsten films using SF$_{6}$ plasma were conducted to investigate the effect of process parameters on etch rate, uniformity, anisotropy, and selectivity. As power increased, the etch rate increased. Maximum etch rate was obtained at 200mtorr As interelectrode spacing increased the etch rate increased for P < 200mtorr while it decreased for P> 200mtorr. Etch rate was maximum at 20 sccm gas flow rate. As substrate temperature increased, the etch rate increased and activation energy was 0.046 eV. In addition, maximum etch rate was acquired at 20% $O_{2}$ addition. The etch rate slightly increased when Ar was added up to 20% while it continuously decreased when N$_{2}$ was added. Uniformity got improved as pressure decreased and was less than 4% for P <100mtorr. Mass spectrometer was utilized to analyze gas composition and S and F peaks were observed from XPS analysis with increasing power. The anisotropy was better for smaller power and spacing, and lower pressure and temperature. It improved when CH$_{4}$ was added and anisotropic etch profile was obtained when about 10% $O_{2}$ was added. The selectjvity was better for smaller power larger pressure and spacing, and lower temperature. Especially. low temperature processing was proposed as a novel method to improve the anisotropy and selectivity.

• 한국진공학회지
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• 제14권3호
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• pp.159-164
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• 2005

Indium tin oxide (ITO) films were deposited on a glass slide at a thickness of 280 nm by radio frequency(rf) magnetron sputtering from a ceramic target composed of $In_2O_3\;(90\%)\;+\;SnO_2\;(10\%)$. We investigated the effects of the annealing temperature (Ta) between 200 and 350'E for 30 min in air on such properties as thermal stability, surface morphology, and crystal structure of the films. X-ray diffraction spectra revealed that all the films were oriented preferably with [222] direction and [440] direction and the peak intensity increased with increasing annealing temperature. X-ray photoelectron spectroscopy (XPS) showed that the sodium was out-diffused from the glass substrate at the annealing temperature of $350^{\circ}C$. The sodium composition of the ITO film amlealed at $350^{\circ}C\;for\;30\;min\;was\;2.5\%$ at the surface. Also the sodium peak almost disappeared after 3 keV $Ar^+$sputtering for 6 min. The visible transmittance of all ITO films was over $77\%$.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.113.1-113.1
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• 2010

IGCC(Integrated Coal Gasification and Combined Cycle) plants can be among the most advanced and environmental systems for electric energy generation from various feed stocks and is becoming more and more popular in new power generation fields. In this work, the performance of IGCC plants employing Shell gasification technology and a GE 7FB gas turbine engine was simulated using IPSEpro open-equation modeling environment for different operating conditions. Performance analyses and comparisons of all operating cases were performed based on the design cases. Discussions were focused on gas composition, syngas production rate and overall performance. The validation of key steady-state performance values calculated from the process models were compared with values from the provided heat and material balances for Shell coal gasification technology. The key values included in the validation included the inlet coal flow rate; the mass flow rate, heating value, and composition of major gas species (CO, H2, CH4, H2O, CO2, H2S, N2, Ar) for the syngas exiting the gasifier island; and the HP and MP steam flows exiting the gasifier island.