• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1997년도 추계학술발표회 논문집
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• pp.47-53
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• 1997

Dynamic models have been developed for the coal gasification process by using a modular approach method. The complete unit is divided, for the convenience of the analysis, into several sections, viz. the coal feeding system, the gasifier, the gas cooler, the valves, the pumps, etc. The dynamic behaviour of each section is described in mathematical terms and each term is modulized into several submodels consisting of the complete process. To represent the behaviour of the fluid flow, the hydraulic network is proposed. Results for the more important system variables are presented and discussed. There dynamic models enable process and control engineers to quickly review a wide range of alternative operating and control strategies and help operators to easily understand the process dynamics and eventually can be applied to the design of commercial scale IGCC plants.

• 한국정보통신학회논문지
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• 제6권3호
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• pp.470-474
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• 2002

본 논문은 CIS를 이용한 문서의 전자문서화 또는 OMR, OCR 인식에 적합한 고속 스캐너스케닝시스템 설계 및 구현에 관한 연구이며 설계기법은 CIS스케닝 센서를 고정한 상태에서 스텝모터를 이용한 기구적 조사방식을 적용하였다. 최적화 시스템을 구현하기 위해 전용의 영상처리프로세서를 사용하였다. 센서를 통해 피딩 스텝단위의 라인 당 입력된 데이터는 시스템 메모리에 저장되고 스케닝 종료위치에 이르면 페이지 당 보관된 메모리의 데이터는 USB 인터페이스 방식을 이용하여 PC로 전송하도록 설계하였다. 구현된 시스템은 소형이며 최대 A4 사이즈의 이미지 스케닝이 가능하고 이미지 스캐닝 시스템 처리속도는 초당 300mm를 유지한다 인식률은 OCR과 바 코드에서 98%이다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.277-279
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• 2003

본 논문은 단일 광원의 CIS에서 조도제어를 적용한 흑백 이미지 스케닝시스템 설계 및 구현에 관한 연구이다. 스케닝 방법은 이미지 스켄센서를 고정한 상태에서 스텝모터를 이용하여 스케닝 하고자 하는 문서를 이동하는 종이공급 방식을 사용하였다. 소형의 최적화된 시스템을 구현하기 위해 전용의 영상처리프로세서를 사용하여 시스템을 구성하였고, 센서를 통해 피딩 스텝마다 1라인의 스케닝된 입력된 데이터는 시스템 메모리에 저장된다. 스케닝을 시작하면 CIS 광원을 ON하여 스케닝하는 문서에서 반사되는 데이터를 수집하게 되는데, CIS 광원을 주기적으로 ON/OFF 하여 스케닝하고자 하는 문서의 조도를 제어하도록 하였다 스케닝 환경에 따라 조도를 제어함으로서 스케닝 이미지에서 적용전의 이미지에 비하여 PSNR이 0.3% 향상 되었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.581-584
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• 2002

본 논문은 CIS를 이용한 문서의 전자문서화 또는 OMR, OCR 인식에 적합한 고속 스캐너스케닝시스템 설계 및 구현에 관한 연구이며 설계기법은 CIS스케닝 센서를 고정한 상태에서 스텝모터를 이용한 기구적 조사방식을 적용하였다. 최적화 시스템을 구현하기 위해 전용의 영상처리프로세서를 사용하였다. 센서를 통해 피딩 스텝단위의 라인 당 입력된 데이터는 시스템 메모리에 저장되고 스케닝 종료위치에 이르면 페이지 당 보관된 메모리의 데이터는 USB 인터페이스 방식을 이용하여 PC로 전송하도록 설계하였다. 구현된 시스템은 소형이며 최대 A4 사이즈의 이미지 스케닝이 가능하고 이미지 스케닝 시스템 처리속도는 초당 300mm를 유지한다. 인식률은 OCR과 바 코드에서 98%이다.

• 에너지공학
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• 제6권1호
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• pp.104-113
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• 1997

본 연구에서는 상용공정모사기인 ASPEN PLUS를 이용하여 건식탄공급, 산소사용 분류층 가스화기인 Shell가스화공정, 저온가스정제공정, GE MS7001FA가스터빈, 삼압.자연순환식 폐열회수보일러, 재열복수식 증기터빈 및 극저온 산소분리공정을 채용한 IGCC시스템에 대하여 성능해석 모델을 개발하고 시스템 성능해석을 위한 민감도분석을 수행하였다. 본 모델의 적정성은 설계조건에서 대상탄을 이용한 정상상태 성능해석 결과를 타 시뮬레이션 결과와 비교함으로서 검증하였다.$^{1)}$ . Illinois#6탄을 대상으로 수행한 시뮬레이션 결과는 투입되는 탄에 함유된 수분의 양이 증가함에 따라 가스화기의 온도가 감소하며, 회분 및 황이 많은 경우에 현열손실이 증가하여 시스템 효율이 감소하였다. 개발된 모델을 이용하여 가스화기의 운전압력, 증기/석탄비율 및 산소/석탄비율에 따르는 시스템의 민감도분석을 수행한 결과 운전압력 증가에 따라 가스화기 노내온도가 상승하며, 가연성가스(CO＋H2) 생성율이 감소하였다. 증기/석탄비율 변화분석에서는 공급증기의 양을 변화시키면 가연성가스의 최고생성점이 보다 낮은 산소/석탄비율에서 나타남을 알 수 있었다. 또한 산소/석탄비율 변화분석에서는 증기/석탄 공급비율 0.2에서 산소/석탄 공급비율이 0.77인 경우에 가장 최적의 운전조건임을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.534-540
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• 2003

This study was conducted to investigate the effect of supplementation of galacto-oligosaccharides (GOS) on methane emission, nutrient digestibility, energy utilization and blood metabolites by Holstein cows fed silages. In two sequential digestion and respiratory trials, two non-lactating Holstein cows were arranged to a balanced incomplete block design. Experimental diets consisted of two silage types; orchardgrass (Dactylis glomerata L.) based silage (OS), mixed silage (orchardgrass based silage and alfalfa (Medicago sativa L.) silage) (MS), while two GOS levels were without supplementation (0) and 2% of dry matter intake supplementation (2). Four combination diets were OS-0, OS-2, MS-0 and MS-2. Significant effects of silage types and GOS supplementation levels were not observed for DM and OM intake. Whereas the digestibility of OM, NDF and ADF was significantly (p<0.05) higher in cows fed OS with and without GOS compared cows fed MS diets. As percentage of GE intake, fecal energy loss for OS diets was significantly (p<0.05) declined than for MS diets. In contrast, cows fed MS diets had lower (p<0.05) urine energy loss as a proportion of GE intake compared to OS diets. Energy loss as CH4 and heat production was numerically increased when cows fed both OS and MS with GOS supplementation. Compared to OS, CH4 emission in cows fed MS was numerically decreased by 10.8 %. Methane conversion ratio (energy loss as CH4 per unit of GE intake) for OS-0, OS-2, MS-0 and MS-2 were 7.1, 7.2, 6.8 and 7.0, respectively. Plasma of glucose and urea-N concentration were significantly (p<0.05) elevated from 1 h to 6 h after feeding, otherwise total protein in plasma was declined (p<0.01) at 6 after feeding.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.181-186
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• 2017

Objective: Leucaena leucocephala (Leucaena) is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS) feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods: Four, rumen fistulated dairy steers with initial weight of $167{\pm}12kg$ were randomly assigned to receive dietary treatments according to a $4{\times}4$ Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control), T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results: Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p<0.05), whereas the amylolytic bacteria population was not affected by treatments (p>0.05). Protozoal population was linearly decreased with increasing level of LS (p<0.05). Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05) and were the highest in 60% LS group. Conclusion: Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1285-1291
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• 1999

A feeding trial was carried out over 238 days to determine the effect of compensatory growth in crossbred calves having 166 kg body weight. Fifteen crossbred calves were divided into two groups of five calves (G1 group) and ten calves (G2 group) as per randomized block design. Growth study was conducted on the feeding of wheat straw based diet containing 60 and 30 percent concentrate supplying equal amount of protein in group G1 and G2 respectively for 119 days (phase - I). At the end of phase-I, calves of G2 group were subdivided in to two groups (G3 and G4). One sub group (G4) received 60% concentrate in their diet (during 120 to 238 days of experiment) while other subgroup G3 received 30% concentrate in their diet (phase-II). The calves of G1 group continued to receive the same diet as during phase-I experiment. Mean DM intake was significantly higher in calves fed high level of concentrate (in G1 and G4 groups), which resulted in significantly higher digestibility of all nutrients except NDF. Nitrogen balance was positive in all the groups and showed significant differences in phase-II (higher nitrogen retention in G4 group than G1 group). ME intake was significantly affected by the level of dietary concentrate, being higher in high concentrate fed group (G1 and G4 than G2 and G3 group). Higher daily body weight gain in the calves of G4 group during phase-II than in G1 and G3 groups was due to compensatory growth on shifting animals from low concentrate to high concentrate based ration. Average daily body weight gain was higher in phase-I than in the phase-II. Protein and energy intake per unit body weight gain were significantly lower in calves fed high concentrate diet.

• Asian-Australasian Journal of Animal Sciences
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• 제30권3호
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• pp.410-416
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• 2017

Objective: This study was to evaluate the sunflower cake and enzymatic complex fed to broilers from 22 to 42 d of age. Methods: In a completely randomized design, a total of 850 birds were allotted in a $2{\times}5$ factorial scheme (with and without enzymatic complex) and five inclusion levels (0%, 5%, 10%, 15%, 20%) of sunflower cake. There were 5 replications and 17 birds in each experimental unit. Data from performance, carcass yield and intestinal morphology were evaluated. Results: Feed intake, weight gain, final weight and feed:gain ratio linearly worsened as sunflower cake increased. For weight gain, final weight and feed:gain ratio, the birds whose diets contained levels of 15% and 20% of sunflower cake showed worse values (p<0.05) than the birds fed the control diet. When fed the enzymatic complex, birds improved (p<0.05) crypt depth and villus:crypt ratio in the jejunum. As inclusion levels of sunflower cake increased, villus depth and villus:crypt ratio in duodenum, jejunum and ileum linearly reduced and the crypt depth linearly increased. Carcass yield linearly reduced as sunflower cake increased. Conclusion: Based on performance, sunflower cake can be used up to 10% in broilers feeding from 21 to 42 days of age.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.382-389
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• 2002

The aims of this study is to evaluate the effect of Aspergillus oryzae Fermentation Extract (AFE) on the performance of lactating cows in summer (May to July) and winter (December to February). The experiment was a completely randomized design (CRD) and dietary treatments were 1) basal diet without AFE, 2) basal plus 3 g/d AFE into the basal total mixed ration (TMR), 3) basal plus 45.4 mg AFE/kg the ensiling corn silage and 4) AFE inclusion in silage and TMR. Twenty-eight cows from each trial were selected and randomly allocated into the four treatment groups, confined in individual pens, and fed ad libitum for 8 weeks in both seasons of feeding trials. Results showed that AFE inclusion in corn silage significantly improved DM intake by 4.4% and milk yield by 3.1% (p<0.05) during summer. In the winter season, AFE inclusion in the diet significantly improved milk yield by 10%. Direct addition of AFE to the TMR even further significantly improved milk yield over the addition through corn silage by 7.4% in winter (p<0.05). An additive effect of AFE inclusion into TMR and through corn silage was also demonstrated in the winter-feeding. AFE inclusion however, did not improve DM intake during the winter trial. In the summer trial, inclusion of AFE showed an adverse effect on the percentage of milk fat, but did not impact on the milk fat yield. Adding AFE through corn silage showed a trend towards alleviating the negative effects of milk fat from direct AFE inclusion in TMR. The similar trend occurred in the winter trial. The inclusion of AFE through corn silage significantly lowered the milk protein content over direct AFE addition, but did not significantly impacted the milk protein yield in summer. AFE supplementation during the winter season significantly increased milk protein content. Adding AFE to the corn silage significantly increased milk protein content over direct AFE addition in winter although inclusion of AFE significantly decreased total milk solid content in the summer (p<0.005). During the winter season, inclusion of AFE required less DM to produce a unit of milk. Inclusion of AFE into corn silage required less DM, energy and protein to produce a unit of milk. But inclusion of AFE did not alleviate heat stress on the lactating cows.