• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 춘계학술발표회 초록집
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• pp.55-55
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• 2003

최근 높은 해상도의 평판 디스플레이 장치 특히 차세대 TFT-LCD를 개발하기 위해서는 건식식각공정의 개발이 필수 불가결하며 이는 플라즈마 공정장치의 대면적화가 가능해야 한다. 따라서 산업계는 이러한 제조 조건에 알맞는 대면적 플라즈마 반응기 개발을 추구하고 있다. 이를 위해서는 건식식각공정의 개발이 필수 불가결하며 이를 위해선 플라즈마 공정장 치의 대면적화가 가능해야 한다. 이러한 대면적 공정을 위해서는 낮은 공정압력, 고밀도, 높은 플라즈마 균일도가 요구된다. 또한 이러한 대면적 고밀도 플라즈마에의 적용을 위하여 새로운 유도결합형 플라즈마 소오스의 개발이 진행되고 있으며, 안정적인 300mm웨이퍼 공정을 위하여 여러 형태의 안테나가 연구되어지고 있다. 그러나 차세대 TFT-LCD에 적용 가 능하게끔 기존의 ICP 소오스를 직접적으로 대면적화 하는데 있어서는 안테나의 인덕턴스의 값이 키지며, 유전물질의 두께 증가 및 그에 따른 재료비의 상슴에 의해 그 한계점을 나타 내었다. 본 연구에서는 차세대 TFT-LCD 및 POP 대면적 공정에 적용 가능한 고밀도 플라즈마를 발생시키기 위해서 내장형 유도결합형 선형 안테나를 사용하였다. 내장형 유도결합형 선형 안테나가 가지고 있는 고유의 정전기적 결합효과를 최소화시키기 위해 직사각형모양의 플라즈마 챔버(830mm*1,020mm)에서 영구자석을 사용하였다. 영구자석을 사용하여 외부자 장을 인가하였을 때가, 그럴지 않은 때보다 RF 안테나에 걸리는 코일의 전압을 낮춰주었으며, 영구자석의 배열에 따라 코일의 인덕턴스의 값이 크게 변함을 알 수 있었다. 그리고, 최적화된 자장의 배열은 플라즈마의 이온밀도를 증가시켰으며, 플라즈마 균일도 또한 10% 이 내로 유지됨을 알 수 있었다. 따른 식각 메커니즘에 대하여 알아보고자 하였다. $CF_4/Cl_2$ gas chemistry 에 첨 가 가스로 $N_2$와 Ar을 첨 가할 경 우 텅 스텐 박막과 하부 layer 간의 etch selectivity 증가는 관찰되지 않았으며, 반면에 첨가 가스로 $O_2$를 사용할 경우, $O_2$의 첨가량이 증가함에 따라 etch s selectivity 는 계속적으로 증가렴을 관찰할 수 있었다. 이는 $O_2$ 첨가에 따라 형성되는 WOF4 에 의한 텅스텐의 etch rates 의 감소에 비하여, $Si0_2$ 등의 형성에 의한 poly-Si etch rates 이 더욱 크게 감소하였기 때문으로 사료된다. W 과 poly-Si 의 식각 특성을 이해하기 위하여 X -ray photoelectron spectroscopy (XPS)를 사용하였으며, 식각 전후의 etch depth 를 측정하기 위하여 stylus p pmfilometeT 를 이용하였다.X> 피막이 열처리 전후에 보아는 기계적 특성의 변화 양상은 열역학적으로 안정한 Wurzite-AlN의 석출에 따른 것으로 AlN 석출상의 크기에 의존하며, 또한 이러한 영향은 $(Ti_{1-x}AI_{x})N$ 피막에 존재하는 AI의 함량이 높고, 초기에 증착된 막의 업자 크기가 작을 수록 클 것으로 여겨진다. 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로

• 한국전기전자재료학회논문지
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• 제18권5호
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• pp.389-395
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• 2005

The etching technology of the high aspect ratio contact(HARC) is necessary at the critical contact processes of semiconductor devices. Etching the $SiO_{2}$ contact hole with the sub-micron design rule in manufacturing VLSI devices, the unexpected phenomenon of 'profile tilting' or 'bottom distortion' is often observed. This makes a short circuit between neighboring contact holes, which causes to drop seriously the device yield. As the aspect ratio of contact holes increases, the high C/F ratio gases, $C_{4}F_{6}$, $C_{4}F_{8}$ and $C_{5}F_{8}$, become widely used in order to minimize the mask layer loss during the etching process. These gases provide abundant fluorocarbon polymer as well as high selectivity to the mask layer, and the polymer with high sticking yield accumulates at the top-wall of the contact hole. During the etch process, many electrons are accumulated around the asymmetric hole mouth to distort the electric field, and this distorts the ion trajectory arriving at the hole bottom. These ions with the distorted trajectory induce the deformation of the hole bottom, which is called 'profile tilting' or 'bottom distortion'. To prevent this phenomenon, three methods are suggested here. 1) Using lower C/F ratio gases, $CF_{4}$ or $C_{3}F_{8}$, the amount of the Polymer at the hole mouth is reduced to minimize the asymmetry of the hole top. 2) The number of the neighboring holes with equal distance is maximized to get the more symmetry of the oxygen distribution around the hole. 3) The dual frequency plasma source is used to release the excessive charge build-up at the hole mouth. From the suggested methods, we have obtained the nearly circular hole bottom, which Implies that the ion trajectory Incident on the hole bottom is symmetry.

• Carbon letters
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• 제26권
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• pp.18-24
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• 2018

Pollution of chloride ion-reinforced concrete can trigger active corrosion processes that reduce the useful life of structures. Multifunctional materials used as a counter-electrode by electrochemical techniques have been used to rehabilitate contaminated concrete. Cement-based pastes added to carbonaceous material, fibers or dust, have been used as an anode in the non-destructive Electrochemical Chloride Extraction (ECE) technique. We studied the performance of the addition of Carbon Fiber (CF) in a cement-graphite powder base paste used as an anode in ECE of concretes contaminated with chlorides from the preparation of the mixture. The experimental parameters were: 2.3% of free chlorides, 21 days of ECE application, a Carbon Fiber Volume Fraction (CFVF) of 0.1, 0.3, 0.6, 0.9%, a lithium borate alkaline electrolyte, a current density of $4.0A/m^2$ and a cement/graphite ratio of 1.0 for the paste. The efficiency of the ECE in the traditional technique using metal mesh as an anode was 77.6% and for CFVF of 0.9% it was 90.4%, with a tendency to increase to higher percentages of the CFVF in the conductive cement-graphite paste, keeping the pH stable and achieving a homogeneous ECE in the mass of the concrete contaminated with chlorides.

• Nano
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• 제13권12호
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• pp.1850141.1-1850141.11
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• 2018

Sodium ion batteries based on the more sodium source reserve than that of lithium have been designed as promising alternatives to lithium ion batteries. However, several problems including unsatisfied specific capacity and serious cyclic stability must be solved before the reality. One of the effective approaches to solve the abovementioned problems is to search for suitable anode materials. In this work, we designed and prepared $FeSe_2$ nanoflakes via a simple hydrothermal method which can be adjusted in composition by Fe precursor. As a potential anode for sodium storage, the optimized $FeSe_2$ electrode was further evaluated in different electrolytes of $NaClO_4$ in propylene carbonate/fluoroethylene carbonate and $NaCF_3SO_3$ in diethylene glycol dimethyl ether. The capacity was about $470mAh\;g^{-1}$ and $535mAh\;g^{-1}$ at $0.5A\;g^{-1}$, respectively, in the voltage between 0.5 V and 2.9 V in the cycle of stabilization phase. Superior performance both in capacity and in stability was obtained in ether-based electrolyte, which affords the property without plugging the intermediates of transition metal dichalcogenides during charge/discharge processes.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.207-208
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• 2000

Since trichloroethylene (TCE), dichloroethylene (DCE), and vinyl chloride (VC) arise from anaerobic degradation of tetrachloroethylene (PCE) and TCE, there is interest in creating aerobic remediation systems that avoid the highly toxic VC and cis-DCE which predonominate in anaerobic degradation. However, it seemed TCE could not be degraded aerobically without an inducing compound (which also competitively inhibits TCE degradation). It has been shown that TCE induces expression of both the toluene dioxygenase of p. putida F1 as well as toluene-p-monooxygenase of P.mendocina KRI. We investigated here the ability of PCE, TCE, and chlorinated phenols to induce toluene-o-xylene monooxygenase (ToMO) from P.stutzeri OX1. ToMO has a relaxed regio-specificity since it hydroxylates toluene in the ortho, meta, and para positions; it also has a broad substrate range as it oxidizes o-xylene, m-xylene, p-xylene, toluene, benzene, ethylbenzene, styrene, and naphthalene; chlorinated compounds including TCE, 1, 1-DCE, cis-DCE, trans-DCE, VC, and chloroform : as well as mixtures of chlorinated aliphatics (Pseudomonas 1999 Maui Meeting). ToMO is a multicomponent enzyme with greatest similarity to the aromatic monooxygenases of Burkholderia pickettii PKO1 and P.mendocina KR1. Using P.sturzeri OX1, it was found that PCE induces P.mendocina KR1 Using P.situtzeri OX1, it was found that PCE induces ToMO activity measured as naphthalene oxygenase activity 2.5-fold, TCE induces 2.3-fold, and toluene induces 3.0 fold. With the mutant P.stutzeri M1 which does not express ToMO, it was also found there was no naphthalene oxygenate activity induced by PCE and TCE; hence, PCE and TCE induce the tow path. Using P.putida PaW340(pPP4062, pFP3028) which has the tow promoter fused to the reporter catechol-2, 3-dioxygenase and the regulator gene touR, it was determined that the tow promoter was induced 5.7-, 7.1-, and 5.2-fold for 2-, 3-, 4-chlorophenol, respectively (cf. 8.9-fold induction with o-cresol) : however, TCE and PCE did not directly induce the tou path. Gas chromatography and chloride ion analysis also showed that TCE induced ToMO expression in P.stutzeri OX1 and was degraded and mineralized. This is the first report of significant PCE induction of any enzyme as well as the first report of chlorinated compound induction of the tou operon. The results indicate TCE and chlorinated phenols can be degraded by P.stutzeri OX1 without a separate inducer of the tou pathway and without competitive inhibition.

• 한국초지조사료학회지
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• 제34권3호
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• pp.179-186
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• 2014

The objective of this study was to determine the best performing switchgrass (Panicumvirgatum L.) cultivar with three different seeding dates as a bioenergy source in Republic of Korea. Split-plot in time with three replications was performed and three switchgrass cultivars, Carthage (CT), Cave-in-Rock (CIR), and Forestburg (FB) were used in this experiment from 2009 to 2012. Plots were seeded on April 23, May 4, and May 13, 2009 and were harvested once in November each year. No fertilizer was applied to the field for the first year; however, in second and third years (June 2010 and May 2011, respectively), N, $P_2O_5$ and K2O fertilizers were applied in 67,45 and 90 kg $ha^{-1}$, respectively. Soil pH (5.9) and climate condition including temperature ($10.4{\sim}17.5^{\circ}C$) and precipitation (89.4~109.8 mm $month^{-1}$) were suitable for switchgrass cultivation. Total dry matter yields were higher in CT and CIR compared to FB and were 16.9, 15.9, and 4.5 ton $ha^{-1}$, for CT, CIR, and FB, respectively (p<0.0001). The samples were analyzed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude fiber (CF), ether extract (EE), and ash. No significant differences in energy content (p = 0.96) and chemical composition among cultivars (p>0.05) were found. Seeding dates did not affect DM yield (ton $ha^{-1}$), chemical composition and energy content significantly (p>0.05). Significant difference was observed for heights among CT, CIR, and FB (177.59, 169.98, and 94.89 cm, respectively, p = 0.0002). In conclusion, based on soil characteristics and climate condition in Korea compared to other countries, switchgrass can be cultivated successfully. Considering dry matter yield and energy content of these three cultivars of switchgrass CT and CIR adapted better to climate in Middle Eastern of Republic of Korea than Forestburg for bioenergy purpose.

• 한국약용작물학회지
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• 제9권2호
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• pp.91-98
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• 2001

남부지방의 황금재배시 토성 및 시비조건에 따른 증수효과(增收效果)를 구명하고자 여천(麗川) 재래종(在來種)을 공시(供試)하여 재식거리를 $40{\times}10cm$로 콘크리트 pot에 토성별 시비조건을 달리하여 4월(月) 1일(日)에 점파하였고 시험을 수행한 결과를 요약하면 다음과 같다. 1. 공시토양의 화학성을 보면 유기물, 유효인산(有效燐酸), 칼리함량은 식양토, 양토, 사양토 순으로 증가되는 경향을 보였고 토양의 물리성은 사양토에서 고상(固相)비율, 식양토에서 공극율이 가장 높았으며 퇴비의 전질소(全窒素) 및 칼리함량이 각각 2.25, 1.59%였고 C/N율은 21.4로 분해가 용역(容易)하였다. 2. 입모률(立毛率)은 퇴비시용구가 $86{\sim}88%$로 높았고 토성 및 시비조건의 생육(生育)은 양토 및 퇴비시용이 경장 및 경태가 각각 $44{\sim}47\;cm$, $7.50{\sim}8.17\;mm$로 가장 길고 굵어져 주당 분지수 및 건경엽중이 각각 $16.6{\sim}18.5$개, $22.1{\sim}26.0\;g$정도로 증가되었다. 3. 지하부 생육을 보면 식양토와 무비구에 비해 양토 및 퇴비 시용구가 주근장 및 주근경은 각각 $2.2{\sim}3.0\;cm$, $1.09{\sim}1.81\;mm$ 정도로 길고 굵어져 상근중 비율도 $2{\sim}6%$ 높아졌으며 주당 건근중이 $2.3{\sim}3.2\;g$으로 무거워 생장량이 증대되었다. 4, 근(根)의 baicalin, baicalein, wogonin 함량은 토성 간에는 식양토가 각각(各各) 9.03%, 2.72%, 1.62% 높은 함량으로 나타났고 시비조건은 무비구(無肥區)(7.13%, 1.35%, 0.49%)에 비해 퇴비 시용구에서 각각 2.80%, 2.45%, 1.91% 높은 함량을 보였다. 5. 토성 및 시비조건에 따른 상관관계는 경장, 주당 분지수, 주근장, 건근중 등의 지참, 지하부생육과 근의 전질소, 가리간에는 정(正)의 상관을 보였고 근의 baicalin, baicalein, wogonin 등의 총 유효성분함량과는 유의적(有意的)인 부(負)의 상관이 인정되었다.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1964-1969
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• 2021

We developed a Dual-PPACs detector for fast neutron measurements that consists of two sets of PPAC: conventional PPAC and fission PPAC. A²³⁸U(U₃O₈) coating is placed in the fission PPAC's anode, which is used as the neutrons conversion layer. An experiment was performed to measure neutron time-of-flight (TOF) in which ²⁵²Cf spontaneous fission source was used. An excellent time resolution of 164ps has been observed at 6 mbar in isobutene gas. With the excellent time resolution of Dual-PPACs detector, exact neutron energy can be extracted from the timing measurement. The experimental detection efficiency was 1.9 × 10^-7, consistent with the efficiency of 2.5 × 10^-7 given by a Geant4 simulation. Ultimately, the results show that the Dual-PPACs detector is a suitable candidate for measuring fast neutrons in the future CiADS system.

• Asian-Australasian Journal of Animal Sciences
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• 제20권7호
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• pp.1067-1075
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• 2007

Twenty eight 3-4 month old castrated Black Bengal kids (Capra hircus) were used to determine the effects of source and level of dietary copper (Cu) concentration on their performance and nutrient utilization. Cu was supplemented (0, 10, 20 and 30 mg/kg diet DM) as copper sulfate ($CuSO_4$, $5H_2O$) or copper proteinate (Cu-P). Kids were fed a basal diet containing maize (19.5%), soybean (17.0%), deoiled rice bran (56.5%), molasses (4.0%), di-calcium phosphate and salt (1.0% each) and mineral and vitamin mixture (0.5% each) supplements at 3.5% of body weight to meet NRC (1981) requirements for protein, energy, macro minerals and micro minerals, excluding Cu. The basal diet contained 5.7 mg Cu/kg, 122.5 mg Fe/kg, 110 mg Zn/kg, 0.26 mg Mo/kg and 0.32% S. $CuSO_4$ or Cu-P was added to the basal diet at the rate of 10, 20 and 30 mg/kg. Kids were housed in a well ventilated shed with facilities for individual feeding in aluminum plated metabolic cages. Blood samples were collected from the jugular vein on d 0, 30, 60 and 90 to determine hemoglobin (Hb), packed cell volume (PCV), total erythrocyte count (TEC), total leukocyte count (TLC) and serum enzymes (alkaline phosphatase, alanine transferase and aspertate transferase). A metabolism trial of 6 days duration was conducted after 90 days of experimental feeding. Statistical analysis revealed that source and level of Cu supplementation improved live weight gain (p<0.04) and average daily gain (p<0.01). No significant contribution of source and level of Cu to alter serum serum enzymes was evident. Goats fed Cu-P tended to have higher Hb, PCV and TEC than with $CuSO_4$ supplementation. Cu-P increased digestibility of ether extract (EE, p<0.02) and crude fiber (p<0.05) and showed an increasing trend (p<0.09) for digested crude protein (CP) and crude fiber (CF). Supplemental dose of Cu linearly improved (p<0.02) digestibilities of dry matter (DM), organic matter (OM), EE and nitrogen free extract (NFE). Though the absorption of nitrogen (N) was not affected (p>0.10) by both source and dose of Cu, N retention was affected (p<0.04) and there was a significant $Source{\times}Dose$ interaction (p<0.05). Final body weight (BW) was not influenced (p>0.10) by the source of Cu but increasing dose of Cu increased (p<0.04) the BW of kids. TDN intake (g/kg $W^{0.75}$) was higher (p<0.05) with the increased dose of Cu and there was a significant $Source{\times}Dose$ interaction. It was concluded that supplementation of Cu from different sources and varying dose level in a concentrate based diet may improve performance, nutrient utilization and plane of nutrition in castrated Black Bengal kids. The effects on performance and nutrient utilization are more pronounced with Cu-P than $CuSO_4$ supplementation. Higher dose of Cu showed better result than lower dose.

• 한국통신학회논문지
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• 제27권12C호
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• pp.1288-1298
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• 2002

타원곡선 암호시스템을 GF(2$^{m}$ )상에서 고속으로 구현하기 위해서는 빠른 나눗셈기가 필요하다. 빠른 나눗셈 연산을 위해선 비트-패러럴 구조가 적합하나 타원곡선 암호시스템이 충분한 안전도를 가지기 위해서는 m의 크기가 최소한 163보다 커야 한다. 즉 비트-패러럴 구조는 0(m$^2$)의 면적 복잡도를 가지기 때문에 이러한 응용에는 적합하지 않다. 따라서, 본 논문에서는 CF(2$^{m}$ )상에서 표준기저 표기법을 사용하여 모듈러 나눗셈 A(x)/B(x) mod G(x)를 고속으로 수행하는 새로운 비트-시리얼 시스톨릭 나눗셈기를 제안한다. 효율적인 나눗셈기 구조를 얻기 위해, 새로운 바이너리 최대공약수(GCD) 알고리즘을 유도하고, 이로부터 자료의존 그래프를 얻은 후, 비트-시리얼 시스톨릭 나눗셈기를 설계한다. 본 논문에서 제안한 나눗셈기는 0(m)의 시간 및 면적 복잡도를 가지며, 연속된 입력 데이터에 대하여, 초기 5m-2 사이클의 지연 후, m 사이클 마다 나눗셈의 결과를 출력한다. 제안된 나눗셈기를 동일한 입출력 구조를 가지는 기존의 연구 결과들과 비교 분석한 결과 칩 면적 및 계산 지연시간 모두에 있어 상당한 개선을 보인다. 따라서 제안된 나눗셈기는 적은 하드웨어를 사용하면서 고속으로 나눗셈 연산을 수행할 수 있기 때문에 타원곡선 암호화시스템의 나눗셈 연산기로 매우 적합하다. 또한 제안한 구조는 기약 다항식(irreducible polynomial) 선택에 있어 어떤 제약도 두지 않고, 단 방향의 신호흐름을 가지면서, 매우 규칙적이기 때문에 필드 크기 m에 대해 높은 유연성 및 확장성을 제공한다.였다. an extraction system, a new optical nonlinear joint transform correlator(NJTC) is introduced to extract the hidden data from a stego image in real-time, in which optical correlation between the stego image and each of the stego keys is performed and from these correlation outputs the hidden data can be asily exacted in real-time. Especially, it is found that the SNRs of the correlation outputs in the proposed optical NJTC-based extraction system has been improved to 7㏈ on average by comparison with those of the conventional JTC system under the condition of having a nonlinear parameter less than k=0.4. This good experimental results might suggest a possibility of implementation of an opto-digital multiple information hiding and real-time extracting system. 촉각에 있는 지각신경세포가 뇌의 촉각엽으로 뻗어 들어가 위의 5가지 신경연접중 어느 형을 형성하는지를 관찰하기 위하여 좌측 촉각의