• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.131-134
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• 2015

국내 천연가스 열량제도를 현행 표준 열량제 $10,400kcal/Nm^3(43.54MJ/Nm^3)$에서 중간 조정기간을 두고 2012.07.01부터는 최저 $10,100kcal/Nm^3(42.28MJ/Nm^3)$을 유지하고 2015년 이후 $9,800(41.1MJ/Nm^3){\sim}10,600kcal/Nm^3(44.4MJ/Nm^3)$ 열량범위제도로 변경 추진되고 있다. 산업현장에서 열량변동을 측정하여 공연비 제어기술을 개발하고자 60ton Al 용해로에 열량대응기술 개발을 위한 내용으로 열량측정시스템설치 및 열량 값과 연계하여 공연비 제어기술개발연구 내용으로 결과는 다음과 같다. 단순히 표준열량으로 에 맞춰 프로그램된 제어로직에 열량변동에서 검출된 신호를 이용하여 연료보정 값을 추가한 로직을 재구성할 필요가 있다. 이 혀장의 경우는 용탕의 온도가 목표온도 근처까지 올리기가 어려워진 상황으로 주로 공급열량 저열량화에 따른 과잉공기영향으로 온도상승이 어려워 보이며 적절한 공연비로 최적화 되면 이러한 문제가 개선되리라 생각된다.

• 농업과학연구
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• 제46권3호
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• pp.417-426
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• 2019

This study was conducted to evaluate seasonal effects on production performance of lactation sows reared in two different environments in South Korea. A total of 76 sows ($Landrace{\times}Yorkshire$) from the Dankook University experimental farm and 120 sows ($Landrace{\times}Yorkshire$) from a commercial farm were collected. In the current study, reduced (p < 0.01) feed intake and energy intake during lactation were observed in warm season compared with cool season in both farms. Sows in cool season had higher backfat thickness at weaning but lower back fat loss (p < 0.01) than those in warm season. The weaning to estrus interval was lower (p < 0.01) in cool season than in warm season. Piglets weaned in warm season had lower (p < 0.01) body weight (BW), body weight gain (BWG), and average daily gain (ADG) at weaning than did those weaned in cool season on the Dankook University farm, whereas the reduction effect was only observed during 0 - 21 d on the commercial farm (p < 0.01). Moreover, piglets weaned in cool season had higher BW, BWG, and ADG (p < 0.05) on both farms. In conclusion, our results indicate that warm season had very negative effects on feed intake and production performance of lactating sows and piglets.

• 농업과학연구
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• 제51권1호
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• pp.1-8
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• 2024

We conducted this research to examine the reducing level of lysine : tryptophan ratios in the diet affected the performance and meat quality of finishing pigs. At the end of the experiment, 144 crossbred finishing pigs (Duroc × [Yorkshire × Landrace]) having an average body weight of 70.6 ± 3.9 kg were randomly assigned to four dietary treatments (9 replications, 4 pigs per pen). The pigs in the 4 treatments were fed diets with different lysine : tryptophan ratios, such as 1 : 0.175, 1 : 0.160, 1 : 0.145, and 1 : 0.130. In considering average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR), the ratio of tryptophan and lysine (Lys : Trp) did not show any significant effect (p > 0.05). Moreover, nutrient digestibility had no significant impact (p > 0.05). However, the decreasing level of tryptophan linearly decreased the back-fat thickness at overall period (p = 0.038) and reduced at week 5 (p = 0.007). Additionally, the lean meat percentage (LMP) showed a tendency to increase at initial (linear effect, p = 0.097) and increased at overall period (linear effect, p = 0.045). Therefore, we suggest that Lys : Trp ratio of 0.130 could enhance the meat quality in finishing pigs.

• 한국축산식품학회지
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• 제27권4호
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• pp.450-456
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• 2007

본 연구는 발효무기물 사료 급여기간 및 급여수준이 한우거세우의 일당증체량, 육량, 육질 및 경제성에 미치는 영향을 검토하고자 급여기간을 두구(T1: 비육후기 7개월 동안 급여, T2: 육성기에서 비육후기까지 18개월 급여)로 하고, 급여수준(농후사료 기준으로 0%, 1%, 2%, 3% 첨가)을 세구 로 하여 총 7처리로 실시하였다. 본 시험에서 얻어진 주요한 결과를 하면 다음과 같다. T1에 있어서 일당증체량은 1%구(1.08 kg) > 2%구(0.90 kg) > 3%구(0.75 kg) > 0%구(0.64 kg) 첨가 순으로 나타났으며, T2에서는 1%구(0.98 kg) > 0%구(0.91 kg) > 3%구(0.89 kg) 순으로 나타났다. 등지방 두께는 T1 및 T2 모두 발효 무기물 사료 첨가량이 높을수록 등지방 두께는 얇아져 육량등급에 매우 유리한 것으로 나타났다. 배장근 단면적은 무처리구(0%)에 비하여 처리구(1%, 2% 및 3%)가 모두 높게 나타났으며, 육질등급에 가장 중요한 근내지방도는 T1에 있어서는 3% 첨가구(4.2)가 T2에 있어서는 1% 첨가구(5.6)가 가장 높게 나타났다. 지방색 및 성숙도에 있어서는 처리구와 무처리구 간에 뚜렷한 경향치를 보이지 않았다. 육량과 육질에 있어서 T1은 3% 처리구가 가장 좋았던 반면 T2에 있어서는 1% 처리구가 가장 좋게 나타났다. 경제성에 있어서는 1% 첨가구가 T1 및 T2에서 가장 높게 나타났다. 이상 결과를 종합해 볼 때, 발효 무기물 사료 1%첨가 급여는 한우 성장 및 육량, 육질을 개선을 함으로써 경제성이 높은 것으로 나타났다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권3호
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• pp.188-195
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• 2004

This paper presents neural load torque observer that is used to deadbeat load torque observer and gain compensation by parameter estimator As a result, the response of the PMSM(permanent magnet synchronous motor) follows that nominal plant. The load torque compensation method is composed of a neural deadbeat observer To reduce the noise effect, the post-filter implemented by MA(moving average) process, is adopted. The parameter compensator with RLSM (recursive least square method) parameter estimator is adopted to increase the performance of the load torque observer and main controller The parameter estimator is combined with a high performance neural load torque observer to resolve the problems. The neural network is trained in on-line phases and it is composed by a feed forward recall and error back-propagation training. During the normal operation, the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. As a result, the proposed control system has a robust and precise system against the load torque and the Parameter variation. A stability and usefulness are verified by computer simulation and experiment.

• 한국정밀공학회지
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• 제28권7호
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• pp.761-768
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• 2011

The large surface micro machining system includes the equipments and processes for manufacturing the ultra precision micro patterned products with large surface through the mechanical machining. Recent major issue on the micro machining technology may be the development of optical parts for the back light unit of display which has the largest market. This special issue makes up with three parts; the large surface micro machining system and machine, machining process and forming process. In this paper, the state-of-the-art and core technology of large surface micro machining system is introduced with focus on the manufacturing technology for the back light unit of LCD TV. Then, some research results on the development of a roll die lathe is introduced which involves the concept of machine design, improvement of thermal characteristics in the spindle system, improvement of relative parallelism and straightness between spindle system and long stroke feed table, machining of micro pitch patterns. Finally, the direct forming process is introduced as the future work in the large surface micro machining field.

• 한국콘텐츠학회논문지
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• 제1권1호
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• pp.8-14
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• 2001

본 논문에서는 의료영상에서 특정 장기를 추출하여 질환 부위를 인식하는 알고리즘을 제안한다. 의료영상이 추출되어진 장기 부위에서 질환을 인식하기 위하여 단일 신경회로망을 이용하면 신경회로망의 학습 능력과 일반화 능력이 한정적이므로 성능개선에 많은 문제가 있다. 따라서 추출된 장기로부터 질환부위를 인식하는 것은 신경회로망을 복합적인 방법, 즉 RBF (Radial Basis Function), BP (Back Propagation)로 구성하여 단일 신경회로망의 단점을 극복하였다. 본 논문에서 제안하는 알고리즘은 입력 의료영상의 다양한 형태 변화에 적응력이 뛰어남을 실험결과로 알 수 있었다. 그리고, 전체 알고리즘의 수행시간이 장기추출 알고리즘을 포함하여 일반적으로 10초 이내에 수행됨을 실험 결과 알 수 있었다. 제안된 알고리즘은 실시간으로 의료영상의 질환부위를 인식하여 판별 자동화를 통해 원격의료에 사용 되어 질 수 있다.

• 한국해양공학회지
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• 제13권3B호
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• pp.38-46
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• 1999

Increasing stringent emissions legislation and requirement of more effective energy used for diesel engine demand the fine control of the fuel injection system. Recently, the electromagnetic fuel injection control system for diesel engine is tried to realize the optimum diesel combustion by the feel back sensing as optical signal of combustion flame. The photo detectors were made for the feed back signal of electromagnetic fuel injection control for small DI diesel engine. Their abilities to detect defining combustion events were examined. By evaluating test results, it was shown that the wider acceptable optical range design of optical probe window face, and selection of installation position and installation method of detector were important point for improving sensing ability. The detector was shown to detect start and end of diffused combustion and maximum point of flame intensity impossible for pressure sensor, and also shown that the maximum point of flame intensity was 75% of accumulated heat release point within the experimental conditions.

• 대한기계학회논문집A
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• 제21권5호
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• pp.828-834
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• 1997

The knowledge of material stress-strain behavior is an essential requirement for design and analysis of deformation processes. Empirical stress-strain relationship and constitutive equations describing material behavior during deformation are being widely used, despite suffering some drawbacks in terms of ease of development, accuracy and speed. In the present study, back-propagation neural networks are used to model and predict the flow stresses of a HSLA steel under conditions of constant strain, strain rate and temperature. The performance of the network model is comparedto those of statistical models on rate equations. Well-trained network model provides fast and accurate results, making it superior to statistical models.

• Journal of Electrical Engineering and Technology
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• 제4권1호
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• pp.28-34
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• 2009

In a Gas Insulated Substation (GIS), Very Fast Transients (VFTs) are generated mainly due to switching operations. These transients may cause internal faults, i.e., layer-to-layer faults in a capacitively graded bushing as it is one of the most important terminal equipment for GIS. The healthiness of the bushing is generally verified by measuring its leakage current. However, the change in current magnitude/pattern is only marginal for different types of fault conditions. Leakage current monitoring (LCM) systems generate large amounts of data and computer aided interpretation of defects may be of great assistance when analyzing this data. In view of the above, ANN techniques have been used in this study for identification of these minor faults. A single layer perceptron network, a two layer feed-forward back propagation network and cascade correlation (CC) network models are used to identify interlayer faults in the bushing. The effectiveness of the CC network over perceptron and back propagation networks in identification of a fault has been analysed as part of the paper.