• Nuclear Engineering and Technology
• /
• 제29권1호
• /
• pp.15-24
• /
• 1997

The design and evaluation of a digital U-tube steam generator level controller of nuclear power plants, which uses model-based compensators to offset the inverse response behavior of water level, is described. Included is a review of steam generator level dynamics, a simulation model that replicates the effects of feedwater and steam flowrate as well as temperature on steam generator level, the design of both the compensators and the overall controller, and the results of simulation studies in which the performances of this model-based controller and existing analog ones were compared. The proposed digital steam generator level controller is stable and its use significantly improves the controllability of steam generator level.

• 한국가금학회지
• /
• 제20권2호
• /
• pp.73-92
• /
• 1993

본 시험은 사료의 에너지 및 단백질수준이 육계의 생산성 및 복강지방 축적에 미치는 영향을 구명하기 위하여 대사에너지 3수준(2,800, 3,000 및 3,200kcal/kg)과 단백질 3수준(16, 18 및 20%)을 조합한 9개 처리를 두었으며, 처리당 암수 각 39수씩 총 702수를 공시하여 1990년 7월 10일부터 9월 4일까지 8주간에 걸쳐 시험을 실시하였던 바 그 결과를 요약하면 다음과 같다. 1. 증체양은 대사에너지수준이 증가할수록 점차 증가하는 경향을 보여 통계적인 유의성이 인정되었으나 (P＜0.05), 대사에너지 2,800kcal/kg과 3,000kcal/kg 또는 3,000kcal/kg과 3,200kcal/kg 수준간에는 유의차가 없었으며, 단백질수준간에도 유의적인 차이를 보이지 않았다. 2. 사료섭취량은 대사에너지 및 단백질수준이 증가할 수록 점차 감소하는 경향을 보였으나 통계적인 유의성은 인정되지 않았다. 3. 사료요구율은 대사에너지수준이 증가할수록 현저히 개선되어 고도의 유의성이 인정되었으며(P＜0.01), 단백질수준이 증가할수록 점차 개선되는 경향을 보였으나(P＜0.05), 단백질 18%와 20% 수준간에는 유의차가 없었다. 4. 도체율은 대사에너지 및 단백질수준간에 일정한 경향이나 통계적인 유의차를 보이지 않았다. 5. 복강지방 축적률은 대사에너지수준이 증가할수록 현저히 증가하는 경상을 보였으나(P＜0.01), 대사에너지 2,800㎉/kg과 3,000kcal/kg 또는 3,000kcal/kg과 3,200kcal/kg 수준간에는 유의차가 없었으며, 단백질 15% 18% 수준간에는 유의적인 차이를 보이지 않았으나 단백질 20%수준에서는 현저히 감소하여 고도의 유의성이 인정되었다. (P＜0.01). 6. kg증체당 사료비는 대사에너지수준이 증가할수록 점차 감소하는 경향이었고, 단백질 16% 및 20% 수준에 비해 18%수준에서 약간 감소하는 경향이었으나, 대사에너지 및 단백질 수준간에 통계적인 유의성은 인정되지 않았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권7호
• /
• pp.947-953
• /
• 2004

The present research was designed to evaluate the effects of pre and post-partum energy level and feeding pattern on the performance of crossbred dairy cows and their calves under farm conditions. A total of 16 crossbred dairy cows were divided into two equal groups on the basis of their body weight and milk production. One group was given 30% less and the another was given 30% more energy than MAFF's (1984) recommendation. After calving all cows were given same ad.libitum diet to assess the effects of feeding during pregnancy on their performance. It was observed that just before calving cows on low energy group gained less (p<0.05) weight than that of the cows on high energy group (12.9$\pm$11.71 vs. 42.25$\pm$12.74 kg/cow. Birth weight of calves of low energy group was lower (p<0.05) than that of the calves of high energy group (17.87$\pm$1.78 vs. 20.73$\pm$2.24 kg/calf). Cows that were on low pre-calving dietary energy level produced less milk during lactation than the cows of high energy pre-calving group (3.45$\pm$0.75 vs. 4.27$\pm$0.79 lit./cow). No significant difference was noticed on calf growth rate and reproductive parameters of cow. Energy level that was 30 % less than MAFF's (1984) recommendation was found to be very low and not suitable for our crossbred cows during their last three months of pregnancy.

• 토지주택연구
• /
• 제2권4호
• /
• pp.379-385
• /
• 2011

국내의 건물부문 에너지 소비량은 전체 소비량의 약 25%를 차지하고 있으며, 생활수준의 향상, 세대수의 증가 등에 기인하여 선진국 수준으로 지속적인 증가추세를 보일 것으로 전문가들은 예측하고 있다. 한편 정부는 2009년부터 녹색뉴딜사업의 일환으로 국토 에너지 수자원 건물 등의 각종 기본정보를 체계적으로 일원화시키고 통합 DB를 구축하는 녹색국가 정보인프라 사업을 추진 중에 있다. 특히 건물과 관련해서는 에너지 절약과 온실가스 저감 대책 마련에 효율적으로 대응하기 위한 수단으로, 건물단위의 에너지 소비량 관리를 기본 골자로 하는 건물 에너지 통합관리시스템 구축을 강구중에 있다. 본 연구에서는 국가 건물에너지 통합관리시스템 구축(이하, 통합관리시스템)에 요구되는 추진계획 및 로드 맵 작성을 목적으로, 기존 에너지 소비량 관련 자료 조사 및 전문가 면담 등의 분석을 통하여 통합관리시스템의 목표와 계획 수립에 따른 단계별 전략과제와 핵심과제를 도출하고자 한다. 나아가, 건물부문의 에너지 및 온실가스 통계 마련과 관리를 위한 통합관리센터의 구축과 운영방안 수립에 활용할 수 있는 방안을 제시하여 향후 녹색뉴딜 사업의 육성을 도모하고자 한다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권12호
• /
• pp.1785-1793
• /
• 2008

Fifty-four PIC barrows were used to evaluate the effects of lower dietary lysine content and energy level on carcass characteristics and meat quality in slaughter pigs. Pigs were allotted to one of three treatments by body weight with six replicate pens in each treatment. The dietary treatments for body weights of 20-50 kg, 50-80 kg and 80-90 kg were as follows, respectively: control diet (digestible energy 14.22 MJ/kg, lysine/DE 0.67 g/MJ, 0.53 g/MJ and 0.42 g/MJ); a low lysine group (digestible energy 14.22 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ); and a low lysine-low energy group or low nutrient group (digestible energy 13.11 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ). The daily weight gain, daily feed intake and feed efficiency were calculated in the overall growth period (nearly 12 weeks). Meanwhile, carcass characteristics and meat quality were evaluated at 60 and 90 kg body weight respectively. During the overall growth trial, lowering dietary lysine and nutrient level both decreased weight gain (p<0.05) and feed efficiency (p<0.01). At 60 kg body weight, decreasing dietary lysine and nutrient level noticeably decreased dressing percentage (p<0.01) and back fat depth at last rib of PIC pigs (p<0.01), but enhanced marbling scores (p<0.10), intramuscular fat content (p<0.10) and water loss rate (p<0.01) of the longissimus dorsi muscle. At 90 kg body weight, lean percentage (p<0.01) was evidently reduced by both lowering lysine content and nutrient level in the diet. However, the shoulder back fat depth (p<0.05) and marbling scores of the loin eye muscle (p<0.05) were increased; Lowering dietary nutrient level could improve back fat depth of 10th rib (p<0.01) and last rib (p<0.01), intramuscular fat content (p<0.10), redness (p<0.01) and water loss rate of the loin eye muscle (p<0.05), but decrease loin area (p<0.05). Finally, when comparing the 60 kg and 90 kg slaughter weights, it was found that the shoulder back fat depth (p<0.01, p<0.10), 6th-7th rib (p<0.01, p<0.01), 10th-rib (p<0.01, p<0.01) and last rib back fat depth (p<0.01, p<0.01) of the low lysine and low nutrient group were all obviously increased comparing with the control group. Taken together, the results showed that decreasing dietary lysine content and nutrient level increased intramuscular fat content and water loss rate of longissimus dorsi muscle; On the other hand, both lowering dietary lysine and nutrient level markedly compensated to increase back fat deposition in the later finishing period (body weight from 60 to 90 kg) in contrast to the control group.

• 전자공학회논문지CI
• /
• 제40권3호
• /
• pp.127-136
• /
• 2003

본 논문에서는 템플릿 변형과 Level-Set 이론을 사용하여 모델과 에지 기반의 객체 추적 방법을 제안한다. 제안된 방법은 배경의 변화, 객체 자체의 모양변화, 객체간의 겹침 등이 있는 경우에도 객체를 추적할 수 있다. 먼저, 객체 추적을 위해 템플릿과 목적 프레임간의 상호 영역 차이(Inter-region distance)와 에지 값으로 구성된 에너지 함수 PDEF(Potential Difference Energy Function)를 새롭게 정의한다. 이 함수는 객체 위치 및 경계 예측과 객체 모양 재결정 단계에서 사용된다. 객체 위치 및 경계 예측 단계에서는 객체의 변화가 어파인(affine) 변형을 따른다는 가정 하에 객체의 대략적인 모양 및 위치를 예측한다. 객체 모양 재결정 단계에서는 퍼텐셜 에너지 지도(Potential energy map)와 수정된 Level-Set 운동 함수를 사용하여 객체의 정확한 형태를 재결정한다. 실험결과에서 제안된 방법은 기존의 방법보다 배경의 변화가 큰경우, 객체 자체의 모양변화가 심한 경우, 객체간의 겹침이 있는 경우 등 다양한 상황이 포함된 동영상에서 정확하게 객체를 추적할 수 있음을 확인할 수 있다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권5호
• /
• pp.680-683
• /
• 2001

The apparent metabolisable energy (AME) and N-corrected ME (AMEn) of deoiled rice bran (DORB) were determined with adult quails at 6 and 10- week of age. The DORB obtained from two types of extraction process, Batch (DORB-B) and the Continuous (DORB-C), was each included in a practical type of the reference diet at 20 or 40% level. The analysed crude protein, ether extract, total ash, calcium, phosphorus, glucose and starch content of DORB-B and DORB-C were found at 19.0, 0.79, 17.05, 0.11, 1.92, 2.3, 11.22, and 15.02, 1.56, 13.0, 0.40, 2.76, 2.16, 19.0, respectively. The level of inclusion of DORB in diet appeared to exert a significant effect on the AME and AMEn values. When bioassayed at 20% inclusion level the DORB was found to have a significantly (p<0.01) lower value than that obtained at 40% inclusion level. However, no significant effect of age of quails on the AME values of DORB was evident. The ME bioassays with quails gave significantly (p<0.01) higher AME values for DORB-C than DORB-B thereby indicating that the continuous system of solvent extraction of rice bran is superior to the batch system from this point of view. The AME value of DORB predicted from its chemical composition also revealed that the DORB-C contained approximately 15% more energy than that in DORB-B.

• Journal of Power Electronics
• /
• 제17권2호
• /
• pp.334-345
• /
• 2017

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

• Journal of Nutrition and Health
• /
• 제30권3호
• /
• pp.277-285
• /
• 1997

The purpose of this study was to investigate the relationship among nutrient intake, life style, and serum lipids level in 108 healthy middle-aged men in Taegu. A convenient method was to assess nutritional intake. Anthropometric measuement of body weight and hight were measured and average energy expenditure was calculated. The mean body mass index(BMI) was 22.8$\pm$2.4 and it was in the middle of the mean BMI of Korean men. Obesity rate of study subject were 13.2%. Daily energy intake was not sufficient as 88.4% of recommended dietary allowances and the energy percentage of carboydrate, fat protein was 65 : 21 : 14. Mean intake of vitamin A, B1, C and Ca were lower than RDA. There was a highly significant negative correlation between the systolic blood pressure and calcium intake(r=-0.28, p<0.05). Smokers showed significantly higher blood glucose than non-smokers. Skipping meals and uneven diurnal distribution(no breakfast and large evening meals) are associated with high triglyceride level in this population. There was a highly significant correlation between body weight and plasma lipids. Energy expenditure was negatively correlated with plasma triglyceride level. Especially, atherogenic index was significantly lower in job-time physically active worker than that in sedentary worker. Above data provides valuable imformation to the community for program planning as well as to health providers who work individual male adults to meet their nutrition needs and to control blood lipids.

• Nuclear Engineering and Technology
• /
• 제44권8호
• /
• pp.911-918
• /
• 2012

Steam generator level control at low power is difficult due to its adverse thermal hydraulic properties, and is usually conducted by an operator. The basic model predictive control (MPC) is similar to the action of an operator in that the operator knows the desired reference trajectory for a finite period of time and takes the necessary control actions needed to ensure the desired trajectory. An MPC is based on a model; the performance as well as the efficiency of the MPC depends heavily on the exactness of the model. In this study, steam generator models that can describe in detail its thermal hydraulic behaviors, particularly at low power, are used in the MPC design. The design scope is divided into two parts. First, the MPC feedwater controller of the feedwater station is determined, and then the MPC level controller for the overall system is designed. Because the dynamic properties of a steam generator change with the power levels, a realistic situation is simulated by changing the transfer functions of the steam generator at every time step. The resulting MPC controller shows good performance.