• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.661-671
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• 2006

Steers (n = 335) of known genetic backgrounds from four fundamentally different growth types were subjected to two production systems to study the main effects and possible interactive effects on carcass composition. Growth types were animals with genetic potential for large mature weight (LL), intermediate mature weight-late maturing (IL), intermediate mature weight-early maturing (IE), and small mature weight-early maturing (SE). Each year, in a nine year study, calves of each growth type were weaned and five steers of each growth type were developed on pasture or feedlot and harvested at approximately 20 and 14 mo of age, respectively. Data recorded were chilled carcass weight and percentages of forequarter, foreshank, chuck, rib, plate, brisket, hindquarter, round, rump, shortloin, sirloin, flank, lean, fat, bone, and retail cuts. The growth $type{\times}production$ system interaction was an important source of variation in chilled carcass weight (p = 0.0395) and percentage retail cuts (p = 0.001), lean (p = 0.001), fat (p = 0.001), rump (p = 0.0454), shortloin (p = 0.0487), and flank (p = 0.001). The ranking of the growth $type{\times}production$ system means for percentage lean was LL-pasture>IL-pasture = IE-pasture = SE-pasture>LL-feedlot, IL-feedlot>IE-feedlot = SE-feedlot. The growth $type{\times}production$ system interaction was non-significant (p>0.05) for forequarter, foreshank, chuck, rib, plate, brisket, hindquarter, round and bone. Growth types of IE and SE yielded greater (p<0.05) mean forequarter than did growth types of IL and LL ($51.6{\pm}0.3$ and $51.5{\pm}0.3$ vs. $51.1{\pm}0.3$ and $50.8{\pm}0.3%$). Mean bone was highest (p<0.05) for the LL growth type and lowest (p<0.05) for the SE growth type ($19.5{\pm}0.5$ vs. $16.8{\pm}0.5%$). Mean bone was greater (p<0.05) for the pastured steers than for the feedlot steers ($21.8{\pm}0.8$ vs. $14.5{\pm}0.6%$). These data indicate that growth type responded differently in the two production systems and that these results should be helpful in the match of genetics to production resources.

• 대한기계학회논문집B
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• 제39권9호
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• pp.727-734
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• 2015

세계적으로 유가 상승에 따른 내연기관의 에너지 변환 효율을 높이고자 하는 연구가 활발히 진행되고 있다. 가솔린엔진에서 높은 열효율을 실현하기 위해서는 희박연소에 의한 비열비의 증가 및 단열화염온도의 저감에 의한 열효율 향상이 필수적이다. 직접분사식 가솔린 엔진은 연료를 직접 연소실에 공급하고 정밀한 연소제어를 통해 희박 연소가 가능하게 하지만 희박연소 한계의 확대와 안정된 희박연소제어가 요구된다. 희박연소 엔진에 대한 삼원촉매의 배출가스 저감특성은 높은 공기과잉률 및 낮은 배기가스 온도로 인해 매우 제한적이다. 이에 효과적인 삼원촉매의 개발을 위해 승용 차량용 엔진의 주요 연비시험 운전조건인 2000 rpm BMEP 2bar 조건에서 공기과잉률의 변화에 따른 배출가스 반응 및 생성 특성을 비교하였다. 희박연소 조건에서 $NO_2$가 생성되었으며, $NO_2$의 비율은 공기과잉률이 증가할수록 증가하고 $N_2O$는 감소하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 춘계학술대회 논문요약집
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• pp.36-36
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• 2004

현재의 제조업들은 극도로 심화된 기업 간의 경쟁과 고객 요구사항의 급변으로 인해 신속한 제품 개발 및 효율적 제조를 요구받고 있다. 생산시스템은 대량생산방식(mass Production)에서 적시/적량 생산방식(lean production)으로 발전해왔고, 최소의 리드타임(lead time)을 갖는 민첩한 생산시스템으로의 발전이 요구되고 있으며, 근래에 새롭게 대두되고 있는 생산 패러다임인 e-Manufacturing에서는 확장된 기업체계 하에서 협업적 제품 개발과 신속 제조(collaborative product development and rapid production)의 달성을 지향하고 있다.(중략)

• 한국자동차공학회논문집
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• 제20권3호
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• pp.106-112
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• 2012

Since air pollution problem by emissions from automotive vehicles has become social issues, lean-burn gasoline direct injection (GDI) engine is focused as an alternative to meet the requirement of reinforced emission regulation and improved fuel consumption. Spray-guided type DI combustion is promising technology, which characterized by the centrally mounted injector and closely positioned spark plug, since stable lean combustion can be realized even at ultra-lean mixture condition. In the present study, the effect of multi-ignition with developed charge coil on combustion and emission characteristics was investigated in optical accessible single cylinder engine. In order to fully understand the in-cylinder phenomena and the mechanisms of emission production, optical diagnostics, such as flame visualization was also carried out at frequently using operating condition. Multi-ignition is effective to improve fuel economy but increase NOx emission at flammability limit.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.551-556
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• 2008

식스시그마는 처음소개 된 이래로 20련 동안 전략적인 측면과 방법론적인 측면 모두에서 식스시그마는 끊임없는 변화를 거듭하고 있다. 식스시그마와 다른 비즈니스 전략과의 접목을 통해 보다 높은 시너지효과를 창출할 수 있는 경영혁신전략의 개발에 대한 관심은 대단히 높다. 린 생산방식 등과의 접목에 대해 많은 연구와 실행이 추진되고 있으며 특히, 린과 식스시그마가 접목된 린 식스시그마는 식스시그마를 통해 성과를 올린 여러 기업들이 보다 발전된 형태의 혁신전략으로서 도입을 추진하고 있다. 하지만 현재 린과 식스시그마를 접목한 린식스시그마에 대한 연구나 여러 기업들의 적용이 이루어지고 있지만 건설분야에서는 연구나 실제 적용사례들이 부족한 상태이다. 이러한 문제점을 해결하고자 6시그마를 이용하여 시행된 프로젝트를 통하여 건설분야에서의 식스시그마의 방법론인 DMAIC의 프로세스를 구체화시키고 선행연구된 린식스시그마 연구를 통하여 DMAIC 프로세스를 발전시키고 건설분야에 식스시그마 DMAIC 프로세스를 재구성하여 제시하고자 한다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.914-919
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• 2009

The research investigates for the relationship between the operating performances of the make-ready process and project production performance. To this end, the researchers proposed a metric of PCR (Percentage of Constraint Removal) to measure the make-ready performance. The study measured the production performance in two ways: production planning reliability and progress performance. We hypothesized that how well the make-ready process is performed has an impact on the degree of production performance. The statistical analyses are used to investigate that how operating performance of the make-ready process affects project production performance. The results of the regression analysis support our hypotheses (p<0.25) and correlation coefficients for the relationship between project production performance and make-ready performance are also significant (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제23권4호
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• pp.475-482
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• 2010

Thirty-six Najdi ram lambs, weighing an average of 24 kg and circa 3 months old, were utilized in this trial to evaluate the effects of various alfalfa hay particle lengths in the diet on growth performance, digestion coefficients, nitrogen retention and carcass characteristics. Lambs were randomly allotted to three dietary treatments: 9.5 and 14 mm diets, where alfalfa hay was processed to 9.5 and 14 mm particle lengths, respectively, mixed with 3 parts of concentrate and pelleted as a total mixed ration (TMR), and long hay diet, where one part of loose alfalfa hay (17.8${\pm}$2.4 cm) was offered in combination with 3 parts of only-concentrate pellet. All dietary treatments were homogeneous in their ingredient composition. All lambs were slaughtered after a 14-week feeding trial. Although the results showed no significant effect of hay particle length on DMI, TDN and DCP, lambs fed the 9.5 mm pelleted diet had higher (p<0.05) final body weight, ADG, gain efficiency and nitrogen retention than lambs fed the 14 mm and long hay diets. Altering the particle length of alfalfa hay in diets did not affect the digestibility of DM or CP, whereas digestibilities of ADF and NDF were 3.7% and 5.4% higher (p<0.05), respectively, for the long hay diet versus the 9.5 mm pelleted diet. Hot carcass weight, percentage of separable lean from the $9-11^{th}$ rib joint, and percentages of protein and EE in the separable lean increased (p<0.05) as the particle length of alfalfa hay in the diet decreased. Under the conditions of this study, the reduction of particle length in the TMR played an important role in enhancing performance without altering DM consumption, and this may lead to more efficient productivity of lamb fattening compared with longer chopping lengths.

• 한국건설관리학회논문집
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• 제2권4호
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• pp.48-61
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• 2001

본 연구에서는 작업 신뢰도 향상의 한 방안으로 기존 공정 관리 기법 상의 한계점을 분석하여 이를 보완하고자 하였다. 그 결과로써 린 생산 원리를 적용한 건설 생산 공정 개선 모델인 CPAM(Construction Process Analysis Model)을 제시하였다. CPAM의 변이 관리 기법을 통해 작업 변이를 최소화시켜 공정계획의 신뢰도 향상 및 생산 효율을 증대시킬 수 있도록 하였고 CPAM에서 제시된 세부작업 일정 계획과 주간작업계획을 통해 건설 현장의 작업 흐름에서 나타날 수 있는 자재, 장비, 인력등의 재고(Inventory or Work In Process, WIP)를 감소시킬 수 있도록 하였다. 또한 본 연구는 건설 생산을 작업 흐름의 관점으로 분석함으로써 기존의 분석에서 놓치기 쉬운 작업 흐름상에서의 불확실성을 최소화시키고 작업 처리량을 최대화시킬 수 있는 대안을 제시하는 데 그 의의가 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.692-698
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• 2005

Two experiments were conducted to examine the effect of graded levels of dietary chromium and leucine, and different fat sources on performance and body composition of broiler chickens. The results showed that chromium picolinate at 0.5 ppm significantly (p<0.05) lowered the carcass fat level. Gut weight and carcass water content were increased as a result of chromium treatment. Body weight, plucked weight, carcass weight, abdominal fat pad weight, breast yield and feed efficiency were unaffected by chromium treatment. Leucine did not interact with chromium to effect lean growth. Dietary leucine above the recommended maintenance level (1.2% of diet) markedly (p<0.001) reduced the breast muscle yield. The addition of fish oil to broiler diets reduced (p<0.05) the abdominal fat pad weights compared to birds on linseed diets. Fish oil is believed to improve lean growth through the effects of long chain polyunsaturated fatty acids in lowering the very low-density lipoprotein levels and triglyceride in the blood, in the meantime increasing glucose uptake into the muscle tissue in blood and by minimizing the negative impact of the immune system on protein breakdown. The amount of fat in the diet (2% or 4%) did not affect body composition.

• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.226-232
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• 1999

Early-weaning at an age of less than 21 days and removal of pigs to a second isolated site, which is commonly referred to as segregated early weaning (SEW), has been shown to substantially reduce disease transfer from the dam. This strategy has been successful in reducing the number of pathogens, but has not been successful in eliminating all pathogens. Although SEW has failed in most instances to totally eliminate pathogens, performance as measured by gain and efficiency through the nursery phase has been shown to be enhanced. In addition, SEW pigs have been shown to perform well on less complex nursery diets. Pigs which are continued on a similar isolation regime to market weight have been shown to have a remarkable improvement in feed intake, gain and efficiency. However, pigs which are co-mingled with conventional pigs after the nursery phase have either no improvement in performance or reduced performance. Backfat and carcass lean yield have been shown to be enhanced by SEW in high lean gain pigs, but not in lower lean gain pigs. Exposure of pigs to antigens which activate the immune system and increase the level of immunological stress has been suggested as the mechanism involved in depressing growth and performance of pigs.