• Carbon letters
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• 제5권2호
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• pp.62-67
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• 2004

Performance of carbon-carbon composites is known to be influenced by the fibre matrix interactions. The present investigation was undertaken to ascertain the development of microstructure in such composites when carbon fibres possessing different surface energies (T-300, HM-35, P120 and Dialed 1370) and pitch matrices with different characteristics (Coal tar pitch $SP110^{\circ}C$ and mesophase pitch $SP285^{\circ}C$) are used as precursor materials. These composites were subjected to two different heat treatment temperatures of $1000^{\circ}C$ and $2600^{\circ}C$. Quite interesting changes in the crystalline parameters as well as the matrix microstructure are observed and attempt has been made to correlate these observations with the fibre matrix interactions.

• Journal of Korean Neurosurgical Society
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• 제65권6호
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• pp.779-789
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• 2022

Objective : To analyze the effects of the number and shape of fenestrations on the mechanical strength of pedicle screws and the effects of bone cement augmentation (BCA) on the pull-out strength (POS) of screws used in conventional BCA. Methods : For the control group, a conventional screw was defined as C1, a screw with cannulated end-holes was defined as C2, a C2 screw with six pinholes was defined as C3, and the control group type was set. Among the experimental screws, T1 was designed using symmetrically placed thru-hole type fenestrations with an elliptical shape, while T2 was designed with half-moon (HM)-shaped asymmetrical fenestrations. T3 and T4 were designed with single HM-shaped fenestrations covering three pitches and five pitches, respectively. T5 and T6 were designed with 0.6-mm and 1-mm wider fenestrations than T3. BCA was performed by injecting 3 mL of commercial bone cement in the screw, and mechanical strength and POS tests were performed according to ASTM F1717 and ASTM F543 standards. Synthetic bone (model #1522-505) made of polyurethane foam was used as a model of osteoporotic bone, and radiographic examinations were performed using computed tomography and fluoroscopy. Results : In the fatigue test, at 75% ultimate load, fractures occurred 7781 and 9189 times; at 50%, they occurred 36122 and 82067 times; and at 25%, no fractures occurred. The mean ultimate load for each screw type was 219.1±52.39 N for T1, 234.74±15.9 N for T2, 220.70±59.23 N for T3, 216.45±32.4 N for T4, 181.55±54.78 N for T5, and 216.47±29.25 N for T6. In comparison with C1, T1, T2, T3, T4, and T6 showed significantly different ultimate load values (p<0.05). However, when the values for C2 and the fenestrated screws were evaluated with an unpaired t test, the ultimate load value of C2 significantly differed only from that of T2 (p=0.025). The ultimate load value of C3 differed significantly from those of T1 and T2 (C3 vs. T1 : p=0.048; C3 vs. T2 : p<0.001). Linear correlation analysis revealed a significant correlation between the fenestration area and the volume of bone cement (Pearson's correlation coefficient r=0.288, p=0.036). The bone cement volume and ultimate load significantly correlated with each other in linear correlation analysis (r=0.403, p=0.003). Conclusion : Fenestration yielded a superior ultimate load in comparison with standard BCA using a conventional screw. In T2 screws with asymmetrical two-way fenestrations showed the maximal increase in ultimate load. The fenestrated screws can be expected to show a stable position for the formation of the cement mass.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2004년도 추계학술발표대회논문집 제23권 2호
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• pp.93-96
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• 2004

본 논문은 TMS320C5501 16bit DSP를 적용한 실시간 화자독립 연속 숫자인식기의 구현에 관해 서술한다. 하드웨어 모듈의 구성은 TMS320C5501 300MHz DSP, 코덱으로는 TLV320AIC1103, SDRAM, 외부장치와의 인터페이스를 위한 HPI, Uart, MIC, SPK Out 단자로 구성되었다. 음성인식 알고리즘은 HM-Net 방식을 사용하였고 고정소수점 연산처리 방식으로 C를 이용한 최적화 작업을 수행하였으며 스트리밍 방식의 인식 방법으로 실시간 처리가 가능하도록 구현하였다. 숫자 인식에 사용한 모델은 41음소에 기반한 트라이폰을 학습하였으며, 특징 파라미터로는 LPCMEL 20차를 사용하였다. 임베디드 시스템의 실시간 음성인식 시스템 구성에 중점을 두었으며 PC상에서의 성능과 비교해 볼때 본 DSP 상에서 500단어, 50문장의 인식을 평균 1.5초 전후로 인식하도록 하였으며 간단한 연결 단어 인식을 수행하는데 무리 없음을 보여준다. 특별히 한국어 연속숫자 부분에 중점을 두었고, 본 연구에서 구현된 연속 음성인식 시스템에 사용된 숫자 인식에서 음절 바이폰 모델에 대하여 $92.92\%$의 인식율을 얻을 수 있었다.

• 한국농공학회지
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• 제31권2호
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• pp.104-115
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• 1989

In an effort to clarify the wetted patterns of sandy loam soil under trickle irrigation conditions, the distance of wetted zone, infiltration capacity and soil wetted patterns, etc. were measured by gypsum block as soil moisture sensor located every 5 cm vertically and horizontaly in the soil bin under the such conditions as a). irrigation rates set to 2, 4, 6, 8 liters per hour b). total amount of water applied fixed to 14.62 liters per soil bin c) the hearing force of soil measured by plate penetrometer ranging from 1.04 to 1.22kg/cm$_2$ The results can be summarized as follows ; 1. The wetted distance in horizontal direction(H), the wetted distance in vertical direction(D), the horizontal infiltration capacity (iH) and the vertical infiltration capacity(in)could by explained as a function of time t. 2. The horizontal wetted distance (H) is explained by an exponetial function H= a$.$ t where b was found ranging from 021 to 026 under surface trickle irrigation, which was considered a lotlower than the classical value of 0.5 and these measurements were indifferent to the increasing irrigation rates. 3. As for the surface trickle irrigation where horizontal infiltration capacity(iH) is explained as iH = A $.$ t h, the coefficient A increases with respect to irrigation rates within the limits of 0.89~1.34. 4. In terms of surface trickle irrigation of the ratio of Dm Which is maximum vertical wetted distance to Hm, which is maximum horizontal wetted distance, found to be within range of 1.0 to 1.21. It was also noted that the value of Dm decreses when irrigation rates increases while the value of Hm changes the opposite direction. 5. The optimum location of sensors from emitter for surface trickle irrigation should he inside of hemisphere whose lateral radius is 28~30cm long and vertical radius is 10~12cm long. The distance between emitters should be within 60cm long. 6. In the study of vertical wetted distance( D) where D= a $.$ tb, the exponential coefficient b ranged from 0.61 to 0.75 in surface trickle irrigation, and from 0A9 to 0.68 for subsurface trickle irrigation. These measurements showed an increasing tendency to with respect to irrigation rates. 7. In case of vertical infiltration capacity( in), where iD= A $.$ t 1-h, the coefficient A for surface trickle irrigation found to be within range of 0.16 to 0.19 and did not show any relationships with varying degree of irrigation rates. However, the coefficient was varying from 0.09 to 0.22 and showed a tendency to increase vis-a-vis irrigation rates for subsurface trickle irrigation, in contrast. 8. In the observation of subsurface trickle irrigation, it was found that Dm/Hm ratio was within 1.52 to 1.91 and showed a decreasing tendency with respect to increasing rates of irrigation. 9. The location of sensors for subsurface trickle irrigation follows same pattern as above, with vertical distance from emitter being 10~17cm long and horizontal 22~25cm long. The location of emitter should be 50 cm. 10.The relationship between VS which is the volume of wetted soil and Q which is the total amount of water when soil is reached field capacity could be explained as VS= 2.914Q0.91and the irrigation rates showed no impacts on the above relationship.

• 한국응용과학기술학회지
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• 제12권2호
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• pp.121-130
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• 1995

This project has been worked out for isolation of EPA-producing bacteria from marine source of sea water, sea sediment and intestinal contents eviscerated from some red-muscle fish such as mackerel, horse-mackerel and spike fish. The samples were precultured on the media of PPES-II glucose broth and then pure-cultured on Nutrient agar and P-Y-M glucose. Lipids extracted from those bacterial mass collected by centrifugation were analysed in terms of lipid class and fatty acid composition. The results are resumed as follows : 1. 112 strains from sea water and 76 strains from sea sediment were tested for their EPA producing capability, but both strains of (SA-67 and SA-91) from the former and four strains(SS-35, 37, 51 and 71) from the latter have been proved to produce EPA above the level of 2% of total fatty acids. The strains such as GS-11, 29, 31, HM-9, 29, B-18, 33, 107, YL-129, 156, 203, 77, 104 and 256 which were isolated from fish intestinal contents, have also produced EPA at higher level than 2% of total fatty acids. 2. Contents of total lipids extracted from the cultures of these strains grown at $25^{\circ}C$, range from 2.8% to 6.9% (on dry weight %), and they are mainly composed of polar lipids($40.9{\sim}52.9%$) such as phosphatidyl glycerol($^{+}cardiolipin$)(?) and phosphatidyl ethanolamine ($33.8{\sim}40.0%$), with smaller amount of free fatty acid ($11.2{\sim}20.2%$). 3. EPA was isolated from a mixture of fatty acid methyl esters obtained from the lipid of each strain by HPLC in silver-ion mode and was identified by GC-Mass spectrometry. 4. The strains of SW-91, GS-11, GS-29, HM-9, B-18 and YL-203 grown at $25^{\circ}C$ have a level of 5% EPA in their total fatty acids, and the GS-11 and HM-9 strains show a tendency of increase in the EPA level with an increase of growth temperature.

• 대한임상검사과학회지
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• 제37권2호
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• pp.78-83
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• 2005

The optimum conditions of Cordyceps militaris mycelial growth, purification and characteristics of branched-chain amino acid aminotransferase [BCAT(EC 2.6.1.42)] in this mycelium were studied. Optimum pH, temperature and medium of culture of mycelia were 5.5, $22.5^{\circ}C$ and Hamada medium (HM), respectively. BCAT in homogenate of this mycelia was precipitated by 20-40% saturated solution of ammonium sulfate and then purified by DEAE (diethylaminoethyl)-Sephadex A-50 column chromatography with linear concentration gradient and Sephadex G-200 gel filtration. A single band of purified enzyme was detected on SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis). Optimum pH and temperature of BCAT were found to be 7.8 and $29^{\circ}C$, respectively. It showed activity toward L-leucine, L-isoleucine and L-valine as a substrate. The Km values of this enzyme for L-leucine were determined to be 5.88 mM for L-leucine.

• 한국균학회지
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• 제31권1호
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• pp.1-7
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• 2003

Beauveria속균은 2000년 9월 1일부터 2002년 8월 31일까지 총 151개 표본이 채집되었고 분리된 균주는 25개다. 분리된 균주는 대부분 Beauveria bassiana에 속하는 것으로 나타내었다. 춘천시 삼악산에서 채집한 유충노랑곰보 동충하초의 특성은 기주를 균사에 의하여 쌓여있으며 자좌는 기주로부터 하나 내지 4개가 나오며 분생포자도 같이 형성되었다. 밝은 노란색의 자좌는 45 mm 이고 머리는 $17mm{\times}4mm$ 이고 자루 28mm 이지만 경계는 뚜렷하지 않았다. 자낭각은 머리에 조밀하게 분포되어 있고 묻힌형이고 크기는 $530{\sim}550{\times}290{\sim}300{\mu}m$이었고 자낭은 $400{\sim}450{\times}4{\sim}5{\mu}m$이었다. 자낭포자는 실 모양이고 2차 포자로 분열한 후 바로 둥근 2차 포자를 형성하였다. Cordyceps staphyl- indaecola의 불완전 세대는 형태적인 특징인 분생자경은 rachis로 분생포자세포는 정단으로 생장하였으며 작은 목에서부터 원형의 분생포자를 형성하였다. 크기는 $2.6{\sim}3.4{\times}1.2{\sim}1.9{\mu}m$로 Beauveria bassiana로 동정하였다. 균사생육에 가장 적합한 배지는 HM이었고 기본 액체배지로는 HM, MCM 배지에서 우수한 건조 균체량을 나타내었다. 11일간 배양하여 $25^{\circ}C$에서 가장 우수한 생장과 밀도를 나타냈으며 $pH6.5{\sim}pH8.5$까지 배지에서 균사생장이 양호하였다. 현미와 번데기 배지에서 균사가 배지의 표면을 채우는 데 일주일이 걸리며 15일이나 18일이 되면 밝은 균사집합체에서 분생자병속이 형성되기 시작하였고 40일 후에는 분생자병속에 분생포자가 형성되기도 하나 간혹 자낭각이 형성되는 자좌도 있었다. 배양에서 형성된 자실체와 자연에서 채집한 자실체는 형태적으로 비슷하나 인공적으로 머리부분에서 자낭각이 형성하게 하는 것은 매우 어려운 것으로 나타났다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2014년도 추계학술대회
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• pp.200-202
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• 2014

본 논문은 High bit-depth 를 위한 SIMD (Single Instruction, Multiple Data) 명령어 기반 보간 필터 고속화 방법을 제안한다. 픽셀 연산을 기반으로 하는 보간 필터링은 HEVC 복호화기에서 높은 복잡도를 차지하고 있지만 반복적인 산술연산을 수행하기 때문에 SIMD 를 이용한 고속화에 적합한 구조를 가지고 있다. 이러한 이유로 본 논문에서는 보간 필터 연산에 대하여 SIMD 명령어를 이용하여 메모리를 효율적으로 사용하여 고속화하는 방법을 제안한다. 제안하는 기술은 HEVC 참조 소프트웨어 HM 12.0-RExt 4.1 에 기반을 둔 ANSI C 기반 자체 개발 HEVC RExt 복호화기 소프트웨어에서 평균 8.5%의 복호화 속도향상을 보였으며, 보간 필터의 수행 시간을 평균 24.8% 향상시켰다.

• 한국동물학회지
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• 제24권4호
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• pp.173-188
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• 1981

근세포의 분화에 있어서의 근특이 단백질의 합성 순서를 구명하기 위하여 계배 근세포를 2$\\sim$9일간 배양하면서 단백질합성야상을 SDS-polyacrylamide 겔전기 영동법, 등전점초점2차원 전기영동법 및 방사자기법으로 분석하였다. Actin은 분화의 초기부터 활발히 합성되어 그 양이 다량으로 축적되나, myosin은 배양 3일째부터 대량 합성되기 시작하였다. Myosin의 대량합성시기는 배양 근원세포가 융합을 활발히 일으키는 시기와 거의 같았다. Myoglobin은 분화초기부터 서서히 합성축적되기 시작하여 배양 5일에서 최대치에 달하였다. Creatine phosphokinase는 배양 3일만에, 그리고 glyceraldehyde dehydrogenase는 6일만에 전기영동상에 검출되었다. Tropomyosin $\\alpha$와 $\\beta$, 그리고 troponin C는 분화초기부터 비교적 다량 합성되고 있었다. 젖산탈수소효소의 활성은 배양 2$\\sim$5일 사이에서 급격히 증가하고 이후 거의 변화가 없었다. 이 효소의 동위효소 조성은 초기 근원세포에서는 $H_4$와 $H_3M$형이 많으나 분화가 진행됨에 따라 $HM_3 와 M_4$형이 서서히 출현하였다. 그리고 배양 5일만에 5종의 동위효소가 모두 검출되었다.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.83-83
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• 2002

The purpose of this study was to investigate the warming temperature and exposed time on the post-thaw survival rate and viability of bovine blastocyst cryopreserved by GMP vitrification. Groups of three bovine IVP blastocysts were sequentially placed into vitrification solution before being loaded into the GMP straws and immersed into LN$_2$within 20 to 25 sec. The warming rate was increased 2 times of warming temperature for improvement of post-thaw survival rates. The frozen embryos were warmed either at 35 or 70$^{\circ}C$ for 1 or 2 sec and then diluted in sucrose solution. Post-thaw blastocysts were serially washed in 0.25 and 0.15 M sucrose in holding medium (HM: TCM199 supplemented with 10% FCS) and TCM-199 for each 5 min, respectively, and then cultured in TCM199 for 24 h. The rate of re-expanded blastocyst was significantly different fer 35 and 70$^{\circ}C$ warming temporature (76.4 vs. 89.3%; P<0.05). The rate of re-expanded blastocyst at 70$^{\circ}C$ for 1 sec was significantly higher than that for 2 sec (91.1 vs. 70.9%; P<0.05). The number of nuclei counted were significantly different among control, 35 and 70$^{\circ}C$ (121${\pm}$8.5 vs. 104${\pm}$11.7 vs. 114${\pm}$10.3; P<0.05). These results indicated that the increasing of warming rate can provide high survival rates of bovine IVP blastocysts. Especially, the best viability of post-thaw blastocyst could be thaw at 70$^{\circ}C$ for 1 sec. The warming temperature and exposed time far warming was considered to be limiting factors to the viability of bovine IVP embryos. he purpose of this study was to investigate the warming temperature and expose.