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( Yongdae Jeong ),( Yohan Choi ),( Doowan Kim ),( Yejin Min ),( Eunsuk Cho ),( Joeun Kim ) 한국축산학회(구 한국동물자원과학회) 2021 한국축산학회지 Vol.63 No.4
This study was conducted to investigate the effect of cooling systems on reproductive performance, body temperature, blood metabolites, and the intestinal microbiome in early gestating sows exposed to high ambient temperature. In total, 39 pregnant sows (Landrace × Yorkshire; 2 parities) were randomly assigned to and maintained in the following three treatment groups (13 sows per group) over days 0 to 35 of pregnancy: (i) air cooling (AC; 26.87 ± 1.23℃), (ii) water-drip cooling (WC; 28.81 ± 0.91℃), and (iii) a lack of cooling with heat stress (HS; 30.72 ± 0.70℃). Backfat thickness was measured before and after HS. Feces were collected on day 0 and 35 d of the trial for microbiome analysis, whereas blood was taken at day 35 of pregnancy and analyzed. Reproductive performance and physiological responses were identified at day 35. Respiration rate along with rectal and skin temperatures were lower (p < 0.05) in the AC group than in the HS and WC groups. Serum blood urea nitrogen values were increased (p < 0.05) in the WC group compared with those measured in the AC and HS groups. Triiodothyronine was found at greater levels (p < 0.05) in the AC than in the HS group. Reproductive performance was not affected by the cooling systems. At the phylum level, fecal pathogenic Spirochaete and Euryarchaeota were found in higher numbers (p < 0.05) in all groups after HS. Similarly, at the genus level, the amount of Treponema was greater (p < 0.05) in all groups after HS. In conclusion, our results suggest that AC or WC can ameliorate or mitigate the adverse effects of HS on the physiological parameters of pregnant sows reared under high temperatures.
Yongdae Jeong,Yohan Choi,Doo-Wan Kim,Joeun Kim,Ye Jin Min,Hyun Jung Jung,Young Hwa Kim 한국축산학회 2020 한국축산학회지 Vol.62 No.6
This study was conducted to investigate the effects of group-housing facility (GHF), compared to an individual confinement stall (CON), on the reproductive performance, behavior, and stress hormones of gestating sows. A total of 50 primiparous sows (Landrace × Yorkshire) were randomly allocated into either CON (n = 25) or GHF (n = 25) during the gestation period. One week before parturition, the sows were transferred into conventional farrowing crates, and cross-fostering was conducted within 1 d of delivery. Blood was collected for analyses of stress indices at 75 d of gestation and postpartum. Reproductive performance was estimated during the period of birth to weaning. Behavior patterns were identified at 90 d of gestation. Litter size was not different between the CON and GHF treatments. Weaning to estrus interval, however, tended to be lower in the GHF than in the CON (p < 0.1). Activity, treating, belly nosing, and exploring behaviors were observed only in the GHF group, whereas rubbing was shown only with the CON. Serum cortisol concentration was lower in the GHF than in the CON at 75 d of gestation (p < 0.05). Sows housed in the GHF showed lower epinephrine and norepinephrine concentrations than those housed in the CON at postpartum (p < 0.05). The GHF sows demonstrated more natural behavior characteristics associated with stress relief than the CON sows with no adverse effects on reproductive performance. Therefore, these results suggest that GHF could be applied as an alternative housing facility to improve animal welfare on swine farms.
열회수형 환기장치 신뢰성 평가를 위한 시험법 검토에 관한 연구
정용대(Yongdae Jeong),신철웅(Cheolwoong Shin),박병용(Beungyong Park),조진균(Jinkyun Cho) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.-
최근, 열회수형 환기장치의 고효율에너지기자재 인증이 종료되고, 미세먼지와 같은 사회적인 이슈가 부각되면서 환기장치에 대한 주변의 인식이 크게 변화하고 있다. 이에 따라 에너지 효율 중심의 기존 환기시장에서 제품의 선택 기준이 다변화 됨에 따라 열회수형 환기장치 외에도, 바닥열, 하이브리드, 자연환기 등의 환기장치가 활성화되고 공기청정기 겸용의 환기장치가 개발되는 등 각 제품의 특징을 살린 제품이 시장에 출시되고 있다. 본 논문에서는 다양한 환기장치의 설치 조건을 고려한 성능평가의 신뢰성 확보를 목적으로 국가표준에 기반한 시험방법을 이용하여 시료의 설치위치 변화에 따른 성능을 측정하였다.
열회수형환기장치의 필터 압력손실 변화에 따른 에너지성능 분석
정용대(Yongdae Jeong),이상문(Sang-Moon, Lee),박병용(Beungyong Park) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.11
본 연구는 고효율의 필터를 부착한 열회수형 환기장치가 필터의 차압에 의해 발생하는 압력손실의 영향으로 풍량이 감소하고 성능이 저하되는 것을 정량적으로 검토하였다. 환기장치의 시험 분석에는 열회수형 환기장치의 KS 인증시험용 시험 장비를 사용하였으며 분석용 환기장치는 시중에 유동되고 있는 150㎥/h의 천장매립덕트형 환기장치를 대상으로 하였다. 환기장치의 성능시험 결과 필터의 장착 전 정격풍량, 유효환기량, 소비전력, 급배기 풍량 비 등 측정된 모든 항목이 KS에서 규정하고 있는 범위 이내 값을 만족하는 것으로 나타났지만, 환기장치에 필터 장착 후 급기측 풍량이 19% 감소하고 누설률 46% 증가하여 환기장치 성능에 큰 영향을 미치는 것을 확인하였다.
하이브리드 다중 Hub-and-Spoke 차량 경로 계획 모형
이용대(Yongdae Lee),정현종(Hyunjong Jeong),손영수(Young Soo Son),윤치환(Chiwhan Yoon) 한국경영과학회 2011 經營 科學 Vol.28 No.3
Hub-and-spoke transportation network is a powerful and useful network structure that takes full advantage of economies of scale on routes between hubs. In recent studies, the network structure is extended to hybrid hub-andspoke that allows direct transportation between spokes. In this study, we considered more extended network structure which is called hybrid multiple hub-and-spoke that has multiple hubs and allows direct transportation between spokes. We developed a mathematical optimization model for automotive service parts transportation planning under hybrid multiple hub-and-spoke network structure. The model suggests a long-term transportation route planning and a short-term vehicle assignment planning. The model is verified by simulation and validated in real world application to Hyundai Mobis automotive service parts transportation planning. From the simulation result, the model reduced the transportation cost about 24.7%, the total distance about 6.8% and the CO2 emissions about 8.8%. In real world application for 6 months from July to December 2010, the model reduced the transportation cost about 9.1% by changing the long-term transportation route without daily vehicle assignment planning.
박병용(Beungyong Park),정용대(Yongdae Jeong),김기용(Giyoung Kim),류성룡(Seong-Ryong Ryu),정창헌(Changheon Cheong) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.11
In this study, the heating performance evaluation for radiant heating method(Base) and convection-radiation combined system(Alt) was conducted. The convection-radiation combined method has a circulation structure in which the heat source returned after the supply hot water passes through the convection heat exchanger is introduced into the radiant heating structure and returned. The measurements were made by comparing standard radiant heating structures with the same size and comparing and analyzing the energy consumption according to the set temperature arrival time, floor temperature distribution and heat supply. The result of energy input was reduced 32%.