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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.
A Geometric Design Study of High-Temperature Position Sensors
Kim, Yongdae,Choi, Hyun Young IEEE 2016 IEEE SENSORS JOURNAL Vol.16 No.19
<P>In this paper, we propose the position sensor designs for high-temperature applications. Oxidation and the chemical reaction of resistive elements, together with the mechanical degradation of component materials at high temperatures, limit the high-temperature applications of conventional position sensors. In order to overcome these drawbacks of conventional position sensors, we designed position sensors consisting of a resistive element, a passivation layer, contact pads, and a conductive brush. The oxidation and chemical reactions of the resistive elements at high temperatures can be prevented by using a passivation layer that has excellent chemical resistance and hardness. Inorganic materials and noble metals that can withstand high temperatures have been used for the resistive elements, the substrate, the electrodes, and the brush. The output signal characteristics of the proposed position sensors are determined mainly by the geometries of the contact pads and the brush. To investigate these geometric effects, three types of position sensors having individual shape of contact pads were fabricated with MEMS technologies and a preliminary performance evaluation at room temperature was carried out. From the preliminary test results, we concluded that S-types were appropriate for high-temperature applications and carried out the performance tests at high temperatures with the S-type position sensor.</P>
Design and Preliminary Evaluation of High-Temperature Position Sensors for Aerospace Applications
Yongdae Kim,Hyun Young Choi,Young Cheol Lee IEEE 2014 IEEE SENSORS JOURNAL Vol.14 No.11
<P>In this paper, high-temperature position sensors for aerospace applications are proposed and geometric design improvements to enhance the performance of the proposed position sensors are derived. Position sensors comprise a resistive element, a conductive brush that moves along the resistive element, and the electrodes at each end of the element. In design of conventional position sensors, the resistive elements are exposed to the atmosphere. This exposure results in oxidation and a chemical reaction with ambient gas at a high temperature. Furthermore, the resistive elements can be damaged by the brush, which is in direct contact with the surface of the resistive element. Materials used for the resistive element, electrode, and substrate limit high-temperature applications of conventional position sensors. To overcome these disadvantages associated with conventional position sensors, novel position sensors were designed that focus on the protection of the resistive elements and the selection of high-temperature materials for the resistive element, electrode, and substrate. The spatial resolution of the proposed position sensors can be improved by densely integrating the patterns of the position sensors using the planar process, which is used to realize microelectromechanical systems and IC devices. In this paper, two types of position sensors were fabricated, and a preliminary performance evaluation at room temperature was carried out in order to validate the concept of the proposed potentiometers; the results of the performance test are presented in this paper.</P>
( 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.
하수관거 정비 계획 수립을 위한 다중 목적 혼합 정수계획 모형
이용대,김승권,김재희,김중훈 한국경영과학회 2003 한국경영과학회 학술대회논문집 Vol.- No.1
In this study, a Multiple Objective Mixed Integer Programming(MOMIP) Model is developed for sewer rehabilitation planning by considering cost, inflow/infiltration. A sewer rehabilitation planning model is required to decide the economic life of the sewer by considering trade-off between cost and inflow/infiltration. And it is required to find the optimal rehabilitation timing, according to the cost effectiveness of each sewer rehabilitation within the budget. To develop such a model, a multiple objective mixed integer programming model is formulated based on network flow optimization. The network is composed of state nodes and arcs. The state nodes represent the remaining life and the arcs represent the change of the state. The model considers multiple objectives which are cost minimization and minimization of inflow/infiltration. Using the multiple objective optimization, the trade-off between the cost and inflow/infiltration is presented to the planner so that a proper sewer rehabilitation plan can be selected.