• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.70-76
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• 2003

Three experiments were conducted to determine the effects of a sorghum-specific enzyme system, derived from an Aspergillus niger and Bacillus subtilis fermentation extract (carbohydrase activity of 1,650 $\alpha$-amylase units and cellulase activity of 30 fibrinolytic units/mL), on growth performance of finishing pigs. In Exp. 1,192 pigs (average initial BW of 46.1 kg) were fed sorghum-based diets without or with 360 mL of enzyme system per ton of sorghum in a 78 d growth assay. For d 0 to 39, gain/feed was improved (p<0.03) with enzyme supplementation, but ADG was not affected (p>0.15). For d 39 to 78 and overall (d 0 to 78), ADG, gain/feed, and digestibilities of DM and N were not affected (p>0.13) by enzyme supplementation. Backfat thickness, fat-free lean index, and scores for stomach keratinization and ulcers also were not affected (p>0.15) by the dietary treatments. In Exp. 2,168 pigs (average initial BW of 58.4 kg) were fed diets without or with 150, 300, or 450 mL/ton of the same enzyme system used in Exp. 1. Adding as much as 450 mL enzyme system / ton of sorghum did not affect (p>0.15) ADG or gain/feed for d 0 to 29 of the growth assay. However, during d 29 to 63, ADG increased by 11% (linear effect, p<0.02) and gain/feed increased by 10% (linear effect, p<0.06) as enzyme concentration was increased from none to 450 mL/ton of sorghum. For the overall period (d 0 to 63), ADG tended to increase (p<0.08) with enzyme supplementation, but gain/feed and digestibilities of DM and N were not affected (p>0.14). Carcass characteristics (dressing percentage, backfat thickness, and fat free lean index) also were not affected (p>0.20) by addition of the enzyme system. In Exp. 3,176 pigs (average initial BW of 46.7 kg) were fed diets without or with 450, 900, or 1,350 mL/ton of the same enzyme system used in Exp. 1 and 2 in a 71 d growth assay. Adding up to 1,350 mL/ton of enzyme had no effects (p>0.15) on ADG, gain/feed, digestibilities of DM and N, and carcass characteristics (dressing percentage, backfat thickness, and fat-free lean index). In conclusion, finishing pigs fed diets with a sorghum-specific enzyme system showed some positive trends for improved growth performance, but those effects were not large and (or) consistent.

• 벤처창업연구
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• 제17권3호
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• pp.19-31
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• 2022

현재 국내 액셀러레이터 시장에서 공공 액셀러레이터의 역할이 점차 확대되고 있다. 이에 따라 향후 정책의 수립을 위해 공공 액셀러레이터의 투자효과를 점검하고 그 타당성을 검증할 필요가 있다. 그러나 국내 액셀러레이터는 그 역사가 짧고 정량적인 자료가 공개되지 않고 있어 액셀러레이터에 관한 재무데이터를 활용한 정량적 연구가 부재한 것이 현실이다. 이에 본 연구는 공공 액셀러레이터의 투자가 스타트업에 미치는 효과를 확인하기 위해 실제 공공 액셀러레이터의 지분투자를 받은 스타트업의 재무데이터를 가지고 실증분석을 진행하였다. 2016년부터 2020년까지 5년간 공공 액셀러레이터가 투자한 112개 스타트업의 재무데이터를 사용하여 회귀분석을 진행하였다. 실증분석 결과 첫째, 공공 액셀러레이터의 초기투자가 스타트업에 대한 성장성과 수익성에 영향을 미치는 것으로 나타났다. 세부적으로 살펴보면 공공 액셀러레이터의 초기투자가 성장성 지표인 매출액 증가율과 총자산증가율에 정(+)의 영향을 미치는 것을 확인하였다. 둘째, 공공 액셀러레이터의 공동투자가 성장성보다는 수익성 지표인 매출액이익률에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 본 연구를 통해 유의미한 결과를 보인 초기 스타트업에 대한 투자를 지속적으로 확대하고 공공 액셀러레이터의 강점인 지원 사업을 결합한다면 스타트업의 성장에 더욱 큰 힘이 될 것으로 생각한다. 본 연구를 통하여 공공 액셀러레이터의 투자 성과를 확인하였으므로 향후 공공 액셀러레이터 사업은 민간 액셀러레이터들의 미흡한 부분을 보완함과 동시에 민간과의 공동투자를 통해 스타트업의 성과를 제고하는 방향의 정책 추진이 필요한 것으로 판단된다.

• 한국언론정보학보
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• 제44권
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• pp.76-107
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• 2008

본 연구에서는 지난 제17대 대통령 선거기간 동안 정치관심도가 유권자들의 미디어 이용(TV, 신문, 인터넷)에 어떠한 영향을 미쳤으며, 미디어 이용이 이명박 후보의 도덕성 평가에 어떠한 영향을 미쳤는지를 분석하였다. 아울러 본 연구에서는 정치관심도와 주요 미디어 이용이 이명박의 도덕성 평가에 미치는 영향이 이명박 지지 집단과 비지지 집단 사이에 어떠한 차이를 보이는지를 살펴보았다. 이를 위해 본 연구에서는 성별 연령별 지역별 전국인구비례에 맞게 모집된 1,199명(여성 584명, 남성 615명, 평균연령(표준편차)=42.77(13.34))의 패널 데이터를 잠재성장모형을 이용하여 분석하였다. 잠재성장모형 분석결과, 상대적으로 정치관심도가 높은 유권자들은 그렇지 않은 유권자보다 미디어 종류에 상관없이 미디어 이용 시간이 많았다. TV 미디어 이용의 경우, 다른 미디어들과 비교하여, 이명박 지지 집단과 비지지 집단 사이에 이명박 후보의 도덕성 평가에 대한 차별성이 상대적으로 약하였다. 신문의 경우, 이명박 비지지 집단에서만 신문 이용이 증가할수록 도덕성 평가가 감소하였다. 인터넷의 경우 TV이용과 같이 이명박 지지 집단과 비지지 집단 모두에서 인터넷 이용의 초기값이 높을수록 도덕성 평가의 초기값이 높았다. 이를 통해 이명박 후보의 도덕성에 대한 판단 여부는 미디어의 종류와 미디어의 이용 정도에 따라서 다르게 나타났음을 알 수 있다. 미디어 이용과 정치행위에 관한 기존의 연구가 대부분 횡단자료에 바탕을 두었기 때문에 변인 사이의 변화에 따른 관련성을 입증하기 어려웠다는 점을 고려할 때, 본 연구의 함의는 종단자료에 대한 분석 방법인 잠재성장모형(latent growth model)을 통해 두 변인의 변화에서의 인과적 관련성을 통계적으로 검증했다는 데 있다.

• Food Science and Biotechnology
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• 제15권5호
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• pp.773-777
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• 2006

Growth of Bacillus cereus was assessed during the storage of seasoned soybean sprouts at 0,5, 10, and $15^{\circ}C$. No lag time in its growth curve was observed and thus the specific growth rate of B. cereus in the exponential growth phase was estimated for bootstrapped microbial count data. The distribution of the specific growth rate could be explained by the BetaGeneral distribution function, and temperature dependence was described by the Ratkowsky square root model. The temperature dependence of the growth could be successfully incorporated into the differential equation of microbial growth to predict the B. cereus count on the seasoned soybean sprouts under fluctuating temperature conditions. Safe shelf lives with different probabilities to reach $10^5\;CFU/g$ were presented at four different temperatures, considering the variation in initial contamination and specific growth rate by the Monte Carlo method and 2-step bootstrapping, respectively. Safe shelf lives defined as the time with a probability of less than 0.1% of reaching the critical limit, were 13.4, 5.2, 3.6, and 2.8 days at 0, 5, 10, and $15^{\circ}C$, respectively.

• KSBB Journal
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• 제13권3호
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• pp.289-294
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• 1998

The effects of various step-fortifications of the initial medium with amino acids, glucose, and vitamines on the growth and metabolism of a hybridoma cell line in batch cultures were quantified. Comparisons between the metabolic rates of the various cultivations were made for the exponential growth phase. Fortification of the basal medium resulted in higher cell densities through a prolonged growth phase, but the maximum specific growth rate was not affected. The uptake rate of glutamine increased with the addition of amino acids but did not change upon the addition of glucose or vitamines. The specific glucose consumption decreased slightly with the addition of amino acids but increased production of lactate and {{{{ { NH}`_{4 } ^{ +} }}}}. A reciprocal relationship between the yields of {{{{ { NH}`_{4 } ^{+ } }}}} and lactate indicated a joint regulation of glycolysis and glutaminolysis.

• 한국환경보건학회지
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• 제33권4호
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• pp.293-298
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• 2007

The microorganism for ammonia gas removal was isolated from composting product. This was identified as Brevundimonas diminuta by morphological, biochemical characteristics study and 16S rDNA sequence analysis. Optimal incubation temperature for cell growth and oxidizing ability of $NH_4-N$ was $30^{\circ}C$ and optimal initial pH was 7. Glucose affected the growth of cell and the removal of $NH4^+$. The growth rate of the isolates were increased when grown in the presence of 0.05-1%(w/v) glucose in the selective medium and lurker increases in glucose concentration to 2% caused significant decreases in the cell growth and oxidizing ability of $NH4^+$.

• 한국해양공학회지
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• 제9권1호
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• pp.83-91
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• 1995

Surface defects in structural members are apt to be origins of fatigue cracks growth, which may cause serious failure of whole structures. Most structure has a part where stress concentrates such as welded joints, corner parts, etc. And then, analysis on crack growth and penetration from these defects, therefore, is one of the most important subjects for the reliability of LBB design. The present paper has performed an experimental and analysis on the fatigue crack propagation by variety in crack length of surface cracked plate with stress concentration part. The crack growth behavior can be explained quantitatively by using Newman-Raju equation and the stress partitioning method proposed by ASME B&P Code Sec. XI. The stress concentration factor $K_t$ has affected on the crack growth. The crack growth after penetration depends upon the initial front side crack length.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.233-236
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• 1999

In this paper. Compression in the case where dissimilar blocks are twinned variously are carried out in the condition of lubricated interface. The degree of growth is experimentally investigated. Moreover, numerical simulations are carried out by the elastic-plastic FEM for the case of the dissimilar blocks with the initial sawtooth angle of $60^{\circ}$ . The dissimilar blocks are twinned, larger difference between material properties leads smaller growth, and the degreased interface leads smaller growth than that in the lubricated one. Furthermore, by the simulation of compression where dissimilar blocks are twinned, it is confirmed that the tendency of the general deformation pattern is very similar to the experiment.

• Journal of Mechanical Science and Technology
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• 제20권5호
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• pp.692-709
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• 2006

Nucleate pool boiling experiments with constant wall temperature were performed using pure R1l3 for subcooled, saturated, and superheated pool conditions. A microscale heater array and Wheatstone bridge circuits were used to maintain the constant wall temperature and to measure the instantaneous heat flow rate accurately with high temporal and spatial resolutions. Images of bubble growth were taken at 5,000 frames per second using a high-speed CCD camera synchronized with the heat flow rate measurements. The bubble geometry was obtained from the captured bubble images. The effect of the pool conditions on the bubble growth behavior was analyzed using dimensionless parameters for the initial and thermal growth regions. The effect of the pool conditions on the heat flow rate behavior was also examined. This study will provide good experimental data with precise constant wall temperature boundary condition for such works.

• Communications for Statistical Applications and Methods
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• 제21권6호
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• pp.521-528
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• 2014

A stochastic Gompertz diffusion model for tumor growth is a topic of active interest as cancer is a leading cause of death in Korea. The direct maximum likelihood estimation of stochastic differential equations would be possible based on the continuous path likelihood on condition that a continuous sample path of the process is recorded over the interval. This likelihood is useful in providing a basis for the so-called continuous record or infill likelihood function and infill asymptotic. In practice, we do not have fully continuous data except a few special cases. As a result, the exact ML method is not applicable. In this paper we proposed a method of parameter estimation of stochastic Gompertz differential equation via Markov chain Monte Carlo methods that is applicable for several data structures. We compared a Markov transition data structure with a data structure that have an initial point.