• 생명과학회지
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• 제20권7호
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• pp.1127-1133
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• 2010

총광합성율의 변이는 순광합성율에 호흡율을 더해서 구한 것으로 계통간의 변이는 순광합성율과 대동소이하였으며 rosetteness는 초장, 초고 그리고 상대엽면적(SLA)과는 고도로 유의한 정의 상관을 보여 초장 및 초고가 클수록 잎의 부착밀도가 낮고 잎이 엷은 것으로 나타났다. 식물의 지상부 생장량은 호흡율에 의해 보다 크게 영향을 받는 것으로 나타났는데 이는 호흡이 잎 뿐 아니라 줄기에서도 일어나는데 기인한 것으로 사료된다. 그리고 엽의 부착밀도가 낮은 계통들이 지상부 생육이 좋았는데, 이것은 광합성율을 높이기 위해서는 상대엽면적(SLA)이 큰 즉, 엽의 두께가 얇은 계통을 선발하는 것이 유리함을 말해 준다.

• 천문학회지
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• 제34권1호
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• pp.25-29
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• 2001

We have constructed a non-spherical model for the hot oxygen corona of Mars by including the effects of planetary rotation and diurnal variation of the Martian ionosphere. Exospheric oxygen densities are calculated by integrating ensemble of ballistic and escaping oxygen atoms from the exobase over the entire planet. The hot oxygen atoms are produced by dissociative recombination of $O^+_2$, the major ion in the Martian ionosphere. The densities of hot oxygen atoms at the exobase are estimated from electron densities which have been measured to vary with solar zenith angle. Our model shows that the density difference of hot oxygen atoms between noon and terminator is about two orders of magnitude near the exobase, but reduces abruptly around altitudes of 2000 km due to lateral transport. The diurnal variation of hot oxygen densities remains significant up to the altitude of 10000 km. The diurnal variation of the hot oxygen corona should thus be considered when the upcoming Nozomi measurements are analyzed. The non-spherical model of the hot oxy-gen corona may contribute to building sophisticate solar wind interaction models and thus result in more accurate escaping rate of oxygens from Mars.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.57-57
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• 2009

In this work, we carried out the variation of surface characteristics of organic polymer films by O2 plasma. The plasma diagnostics were performed by DLP(Double Langmuir Probe) and OES(Optical Emission Spectroscopy) measurements. Moreover, variation of surface characteristics were measured by AFM(Atomic Force Microscope), XPS(X-ray Photoelectron Spectroscopy), and contact angle goniometer. It was found that the etch rate of organic films was controlled by O radicals flux and dc bias voltage. And O radical density and dc bias voltage increased with increasing bias power. So, it was changed surface energy as a function of surface roughness and O/C ratio in organic films.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.67-69
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• 2004

ZnO varistor ceramics which were fabricated with variation of added of 0.01, 0.02, 0.03, 0.05, 0.1mol% $Nb_2O_5$ sintered at $1150^{\circ}C$. In the specimen added 0.05mol% $Nb_2O_5$, sintered density was $5.87g/cm^3$ and electrical properties were superior to any other components. The nonlinear coefficient was 75, and clamping voltage ratio was 1.40. And, endurance surge current in the specimen added 0.05mol% $Nb_2O_5$ was $6500A/cm^2$, and deviation of varistor voltage was -1.7%. As P.C.T and T.C.T environment test were succeed in all specimens, and deviation of varistor voltage in the specimen added 0.3mol% $Nb_2O_5$ was -0.81%. All specimens showed a good leakage current property in the High Temperature Continuous Load Test for 1000hr, at $85^{\circ}C$, and variation rate of the varistor voltage was -1.71%.

• 한국전기전자재료학회논문지
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• 제17권11호
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• pp.1186-1191
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• 2004

ZnO varistor ceramics which were fabricated with variation of added of 0.5～1.0 mol% Co$_3$O$_4$, were sintered at 1150 $^{\circ}C$. In the specimen added 0.7 mol% Co$_3$O$_4$, sintered density was 6.03 g/㎤ and electrical properties were superior to any other compositions. The nonlinear coefficient a and clamping voltage ratio were 83 and 1.35, respectively. But, endurance surge current in the specimen added 0.5 mol% Co$_3$O$_4$ was 7000 A/$\textrm{cm}^2$, and deviation of varistor voltage was Δ-3.23 %. As P.C.T and T.C.T environmental test were succeed in all specimens, and deviation of varistor voltage in the specimen added 0.6 mol% Co$_3$O$_4$ was Δ-0.81 %. All specimens showed good leakage current property on the High Temperature Continuous Load Test(HTCLT) for 1000 hr at 85 $^{\circ}C$ and variation rate of the varistor voltage below Δ-2.0 %.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.201-207
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• 2017

An electron-excited temperature ($T_{ex}$) is not determined by the Boltzmann plots only with the spectral data of $4p{\rightarrow}4s$ in an Ar-plasma jet operated with a low frequency of several tens of kHz and the low voltage of a few kV, while $T_{ex}$ can be obtained at least with the presence of a high energy-level transition ($5p{\rightarrow}4s$) in the high-voltage operation of 8 kV. The optical intensities of most spectra that are measured according to the voltage and the measuring position of the plasma column increase or decay exponentially at the same rate as that of the intensity variation; therefore, the excitation temperature is estimated by comparing the relative optical-intensity to that of a high voltage. In the low-voltage range of an Ar-jet operation, the electron-excitation temperature is estimated as being from 0.61 eV to 0.67 eV, and the corresponding radical density of the Ar-4p state is in the order of $10^{10}{\sim}10^{11}cm^{-3}$. The variation of the excitation temperature is almost linear in relation to the operation voltage and the position of the plasma plume, meaning that the variation rates of the electron-excitation temperature are 0.03 eV/kV for the voltage and 0.075 eV/cm along the plasma plume.

• 한국토양비료학회지
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• 제22권1호
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• pp.18-24
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• 1989

인삼재배(人蔘栽培) 예정지(豫定地) 토양이화학성(土壤理化學性)과 관리후(管理後) 토양이화학성(土壤理化學性) 및 이식후(移植後) 본포(本圃)의 토양이화학성(土壤理化學性) 변화(變化)가 인삼수량(人參收量) 및 결주율(缺株率)에 미치는 영향(影響)을 변화량(變化量)과 변화율(變化率) 모형(模型)을 써서 산지조사의 수행자료(遂行資料)로 해석(解析)하였다. 1. 예정지(豫定地)에서 6년차(年次)까지 토양물리성(土壤物理性)의 연차간(年次間) 변화(變化)는 수분(水分)을 제외(除外)한 입단율(入團率), 공극률(孔隙率) 용적밀도(容積密度)가 유의성(有意性) 있는 변화(變化)가 있었고 토양화학성(土壤化學性)은 Mg을 녹외(綠外)한 전성분(全成分)이 유의성(有意性)있게 변화(變化)하였다. 2. 6연근(年根) 인삼수량(人蔘收量)과 연차간(年次間) 토양물리성(土壤物理性)은 유의성(有意性) 있는 정상관(正相關)이었고 결주율(缺株率)과는 유의부상관(有意負相關)이었다. 토양화학성(土壤化學性)의 연차간변화(年次間變化) 중에서 4년차(年次) 함류농도외(艦類濃度外)에는 유의성(有意性)이 없었다. 3. 6연근수량(年根收量)은 본포기(本圃期) 입단율(粒團率)의 변화량(變化量)과 정상관(正相關)이었고 예정지(豫定地)의 변화량(變化量) 및 변화율(變化率)과 수분변화량(水分變化量)과는 부상관(負相關)이었으며 결주율(缺株率)은 예정지공극률(豫定地孔隙率)의 변화양(變化量)과 부상관(負相關)이었고 예정지(豫定地) 입단변화율(粒團變化率) 및 본포기(本圃期) 수분변화율(水分變化率)과는 정상관(正相關)이었다. 4. 6연근수량(年根收量)과 토양물리성(土壤物理性) 상호간(相互間)의 다중상관(多重相關)을 보면 예정지(豫定地)의 공극률(孔隙率)이 크게 기여하며 입단율(粒團率)만을 볼 때는 본포기(本圃期) 변화량(變化量)의 기여도가 컸다.

• KSBB Journal
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• 제11권3호
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• pp.303-310
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• 1996

해양 미세조류인 Isochrysis galbana Parke의 성장에 미치는 여러 환경요인과 배지요인의 영향을 조사하고 최적 배양조건을 구하였다. 그 결과를 요약하 면 다음과 같다. 1. 인공바닷물은 자연바닷물보다 다소 낮은 비성 장속도와 최종 균체농도를 나타내었다. 2.. 자연바닷물이 기초배지로 사용되었을 때 2mM 이상의 충분한 질산염 농도가 필요하였다. 그러나 미량원소와 비타민의 영향은 관찰되지 않았다. 3. 완충용액요로 Tris를 첨가한 경우 pH는 일정 하게 유지가 가능하나 비성장속도와 최종 균체농도 가 감소하였다. 4. 최적 초기 pH와 온도는 각각 pH 8, $20^{\circ}C$ 였다. 5. 벚세기를 400-21001ux의 범위에셔 변화시켰을 때 비성장속도는 18501ux까지 증가하였고 그 이 후로는 일정하였다. 6. 10mL에서 70mL로 Working volume을 증가 시켰을 때 초기 성장속도는 비슷하였으나 최종 균체 농도가 감소하는 경향을 보였다. 7. Working volume이 30mL일 때 최적 교반속 도는 100rpm정도이고, 더 높은 교반속도에서는 최 종 균체농도의 감소가 관찰되었다. 8. 플라스크배양의 최적조건에서 최대 비성장속도 와 최종 균체농도는 각각 $O.021hr^{-1}$과 1.1g/L로 얻어졌다.

• 한국정보처리학회논문지
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• 제7권7호
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• pp.2246-2253
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• 2000

In this paper, we show that one can enhance the performance of blind segmentation of phoneme boundaries by adopting the knowledge of Korean syllabic structure and the regions of voiced/unvoiced sounds. eh proposed method consists of three processes : the process to extract candidate phoneme boundaries, the process to detect boundaries of voiced/unvoiced sounds, and the process to select final phoneme boundaries. The candidate phoneme boudaries are extracted by clustering method based on similarity between two adjacent clusters. The employed similarity measure in this a process is the ratio of the probability density of adjacent clusters. To detect he boundaries of voiced/unvoiced sounds, we first compute the power density spectrum of speech signal in 0∼400 Hz frequency band. Then the points where this paper density spectrum variation is greater than the threshold are chosen as the boundaries of voiced/unvoiced sounds. The final phoneme boundaries consist of all the candidate phoneme boundaries in voiced region and limited number of candidate phoneme boundaries in unvoiced region. The experimental result showed about 40% decrease of insertion rate compared to the blind segmentation method we adopted.

• 열처리공학회지
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• 제23권3호
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• pp.131-136
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• 2010

The LCF (low cycle fatigue) behavior and the serration phenomena in the plastically deformed and non-deformed 5052 Al alloy were investigated. The plastic deformation was performed by 1 pass or 4 passes in ECAP (equal channel angular pressing) followed by annealing. Only cyclic hardening continued from the beginning until fracture at all strain amplitudes during LCF in the non-deformed alloy, which was caused by the increase in dislocation density during fatigue. Slight cyclic hardening followed by plateau until fracture was observed during LCF in the ECAPed alloy, which was caused by the slight increase in dislocation density in the beginning and then keeping constant in dislocation density afterward until fracture by forming subgrains in this stage of fatigue. The serrations on the stress-strain curves of this alloy were observed, which indicate that the dynamic strain aging (DSA) is occurring during plastic deformation. The variation in amplitudes of serration was studied by changing the strain rate in tensile or fatigue tests.