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        검색결과 220

        3.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        On pig farms, the highest mortality rate is observed among nursing piglets. To reduce this mortality rate, farmers need to carefully observe the piglets to prevent accidents such as being crushed and to maintain a proper body temperature. However, observing a large number of pigs individually can be challenging for farmers. Therefore, our aim was to detect the behavior of piglets and sows in real-time using deep learning models, such as YOLOv4-CSP and YOLOv7-E6E, that allow for real-time object detection. YOLOv4-CSP reduces computational cost by partitioning feature maps and utilizing Cross-stage Hierarchy to remove redundant gradient calculation. YOLOv7-E6E analyzes and controls gradient paths such that the weights of each layer learn diverse features. We detected standing, sitting, and lying behaviors in sows and lactating and starving behaviors in piglets, which indicate nursing behavior and movement to colder areas away from the group. We optimized the model parameters for the best object detection and improved reliability by acquiring data through experts. We conducted object detection for the five different behaviors. The YOLOv4-CSP model achieved an accuracy of 0.63 and mAP of 0.662, whereas the YOLOv7-E6E model showed an accuracy of 0.65 and mAP of 0.637. Therefore, based on mAP, which includes both class and localization performance, YOLOv4-CSP showed the superior performance. Such research is anticipated to be effectively utilized for the behavioral analysis of fattening pigs and in preventing piglet crushing in the future.
        4,000원
        4.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We aimed to investigate the effect of environmental enrichment via toys on the behaviour and performance of weanling pigs. A total of 300 pigs (LYD) were housed in different pens with ten pigs per replicate and ten pigs per head divided into 3 groups. Group 1 was called “CON” and received no toys, group 2 was TOY-2, and pigs in this group had access to toys in the first 2 weeks, and lastly, pigs in TOY-4 were given toys in the fourth week. The pigs had access to feed and water ad-libitum. The individual pig behaviours in each group was recorded on days 14 and 28 (d 14 and 28) with a video camera for accuracy. The results showed higher (p<0.05) overall ADG in TOY-4 compared with CON, while the overall ADFI was higher (p<0.05) in TOY-supplemented groups compared to CON. Diarrhea incidence and fecal score were lower on D 14 in TOY-supplemented groups compared with CON. Behavioural features such as ear biting and fighting were lower (p<0.05) in TOY-supplemented groups compared with CON on D 14. Tail biting was lower (p<0.05) in TOY-2 compared with CON at D 14. Conversely, at D 28, tail biting was lower (p<0.05) in TOY-4 compared with CON. The ADG improved due to the toy supplied to reduce undesirable social behaviours. We concluded that the environmental enrichment of pens with toys can help to improve the welfare in weaning pigs, leading to a greater survivability and more production thereby improving farmer incomes.
        4,000원
        5.
        2023.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        One-dimensional MgO nanostructures with various morphologies were synthesized by a thermal evaporation method. The synthesis process was carried out in air at atmospheric pressure, which made the process very simple. A mixed powder of magnesium and active carbon was used as the source powder. The morphologies of the MgO nanostructures were changed by varying the growth temperature. When the growth temperature was 700 °C, untapered nanowires with smooth surfaces were grown. As the temperature increased to 850 °C, 1,000 °C and 1,100 °C, tapered nanobelts, tapered nanowires and then knotted nanowires were sequentially observed. X-ray diffraction analysis revealed that the MgO nanostructures had a cubic crystallographic structure. Energy dispersive X-ray analysis showed that the nanostructures were composed of Mg and O elements, indicating high purity MgO nanostructures. Fourier transform infrared spectra peaks showed the characteristic absorption of MgO. No catalyst particles were observed at the tips of the one-dimensional nanostructures, which suggested that the one-dimensional nanostructures were grown in a vapor-solid growth mechanism.
        4,000원
        9.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The initial smoothness of concrete pavement surfaces must be secured to ensure better driving performance and user comfort. The roughness was measured after hardening the concrete pavement in Korea. When the initial roughness is poor, relatively large-scale repair works, such as milling or reconstruction must be performed. Hence, a method to measure the roughness of the concrete pavements in realtime during construction and immediately correct the abnormal roughness was developed in this study. METHODS : The profile of a concrete pavement section was measured at a construction site using sensors that were attached to the tinning equipment of the paver. The measured data included outliers and noise caused by the sensor and vibration of the paving equipment, respectively, which were further calibrated. Consequently, the calibrated data were input into the ProVAL program to calculate the roughness based on the international roughness index (IRI). Additionally, the profile of the section was re-measured using another method to verify the reliability of the calculated IRI. RESULTS : The profile data measured at the concrete pavement construction site were calibrated using methods, such as overlapped boxplot outlier removal and low-pass filtering. The outlier data from the global positioning system (GPS), which was installed to identify the construction distance, was also calibrated. The IRI was calculated using the ProVAL program by matching the measured profile and GPS data, and applying the moving average method. The calculated IRI was compared to that measured using another method, and the difference was within the tolerance. CONCLUSIONS : A method to measure the roughness of the concrete pavements in real time during construction was developed in this study. Hence, the performance of concrete pavements can be improved by enhancing the roughness of the pavement considerably using the aforementioned method.
        4,600원
        10.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, halogen lamps for vehicle exterior lamp systems are being replaced by LEDs (Light Emitting Diode) in consideration of miniaturization, power consumption, life, luminance, and eco-friendliness. Due to regulations on the amount of light required, luminance, light uniformity, and glare prevention, it is required to develop a light guide for controlling a light source of an LED lamp for a vehicle. For the development of the light guides, the development of machining technology that can cut micro patterns of hundreds of micrometers scale into surface roughness of tens of nanometers scale must be preceded. In this study, the effect of variations in cutting conditions on surface roughness was analyzed through experiments. The micro patterns was manufactured by cutting into STAVAX material, and the surface of the micro patterns was super-finished using a ball-shaped PCD (polycrystalline diamond) tool without flutes. In experiments, the cutting conditions of the super-finishing process were varied, and the varied cutting conditions were feed rate, radial depth of cut, and spindle speed
        4,000원
        11.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the effects of ImmunoSEB as an immune-booster additive on the performance of broiler chicks. A total of 1150 broiler chickens were randomly allotted to three treatments on the basis of body weight (10 pens per treatment with 40 broilers in each pen): the control (CON), CON + ImmunoSEB 0.025% in feed (SEB25), and CON + ImmunoSEB 0.050% in feed (SEB50). The experiment was conducted for d 42 in three phases (phase 1, d 0–14; phase 2, d 15–28; and phase 3, d 29–42). There were significant differences in the average daily gain (ADG) and feed intake. The ADG at d 14 in the SEB50 treatment was greater than that in the CON treatment. The overall ADG in the SEB50 treatment was greater than that in the CON treatment. During d 0–14, the feed intake of chickens in the SEB50 treatment increased compared to that in the CON treatment. The crude protein and lysine digestibility improved in the SEB25 and SEB50 treatments compared to those in the CON treatment at d 28. Superoxide dismutase concentration significantly increased in the SEB50 treatment compared to that in the CON treatment. The interleukin-1β and tumor necrosis factor-α concentrations were higher in the cecum of chickens in the CON treatment than in the SEB25 and SEB50 treatments. A lower population of E. coli was detected in the ileum and cecum of broilers fed the SEB50 diet compared to those of broilers fed the CON diet. The overall result showed the beneficial effects of using ImmunoSEB at a dose of 0.050% in broiler chickens.
        4,200원
        15.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, the dynamics equations for a demolition fire vehicle were formulated. This was done by developing an interface that allows co-simulation using ADAMS and MATHEMATICA. In this study, MATHEMATICA alone was used to calculate the constrained dynamics equations, to demonstrate the impact force and the constraint Jacobian of the end-effector as any desired location through the x, y and z axes. Then we mathematically derived a model for a unilaterally constrained multi-link. Assumptions about the fire demolition vehicle of the constraint coordinate and the impact issues of the model are discussed in the next sections. The estimation procedure for the dynamics equation showed good approximation results in terms of solving a reaching task problem.
        4,000원
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