Search

In recent years, with the development of fish cage aquaculture technology, the traditional way of bait casting cannot meet the growing demands any more. As fishes feed with certain regularities, it is important to acquire the feeding conditions of the fishes. Through analyzing the images of fishes feed by the way of image processing, the feature of the shape and the area of fishes is extracted. The gross of feeding is setup based on the shape, which reflects the weight of fish. The feeding amount is changed with the variation of the image of fish in feeding at real time. The cast program according the extracted feature and the cage aquaculture experiment is designed to verify the feeding effect. Experimental result shows that the smart cast can setup the bait according to the growing requirement of the fishes. The bait utilization will be increased, and water pollution will be reduced, and the fish quality can be improved as well through the smart cast system. Introduction With the development of marine aquaculture technology, the cage aquaculture develops rapidly for its irreplaceable advantages [1]. Currently fish cage aquaculture is often used feeding machine to cast at a certain time as a certain amount, and this manner of feeding process cannot be modified according to the aquaculture conditions, which wastes too much bait. As the aquaculture technology develops, the feeding machine is needed to cast according to the aquaculture environment and the characteristics of raising species [2]. The amount of bait needed in different growth stages of fishes and the aquaculture environment is different, so the feeding machine should adjust according to the specific situation in real-time [3, 4]. To solve the above problems and needs, this paper studies a way of smart cast used in fish cage aquaculture. To study the regularities of fish feeding by the way of image processing, he control scheme is designed to realize the smart cast which can adapt the regularities of fish growth. The smart cast system can save bait and reduce costs. and it can improve fish quality and protect the marine environment. Research on the regularities of fish feeding In the fish cage aquaculture, fish feeding has some regularity. We can study the regularities through processing the image acquired by the camera [5]. First of all, the image acquisition device is designed to get high quality images for the following image processing; Then process the images through filtering, enhancement, segmentation to separate the fishes from the background of water; At last, the feature of shape and area of feeding fish is extracted to study the variation of the fish feeding process. Image acquisition Using industrial camera and computer to realize the image acquisition, and the camera lens is arranged vertically to reduce the influence caused by the angular difference. The camera is mounted on the bracket to reduce the image blur phenomenon caused by the shake [6]. The images captured by camera are transmitted directly to the computer to process and preserve. Due to the large storage space and the fast memory speed, the computer meets the demand of continuous image acquisition. 2nd Workshop on Advanced Research and Technology in Industry Applications (WARTIA 2016) © 2016. The authors Published by Atlantis Press 1324 Capture the images in the fish breeding base of Ningbo, and the images are showed in Fig. 1. (a) Image before feeding (b) Image in feeding Fig. 1 The original image Image processing Due to the influence of the environment, the images are mixed with the noise signal, which influents the accuracy of image recognition. First of all, image filtering process should be done to reduce the interference of the noise signal; then study the feature of feeding images through the image enhancement and feature extraction [7]. (1) Filtering: The aim of filtering is to reduce the influence of the noise, we use the way of neighborhood average to filter, and the new value of the pixel is equal to the average of the neighborhood pixel value. The formula is

In the Yangtze River basin, winter fallow is popular for the double cropping rice (Oryza sativa L.). In this study, the possibility of adding a rapeseed cropping season after late rice harvest in this area was studied with the purpose of extending direct-seeding rapeseed under no-tillage cultivation pattern. In a 2-year field experiment from 2008 to 2010, the rapeseed cultivar Huashuang 5 (Brassica napus L. cv. Huashuang 5) were planted in 3 locations in Hubei Province of China after harvesting late rice. At both individual and population levels, the effects of plant density and nitrogen (N) application rate on rapeseed growth and yield formation were measured at seedling, budding, flowering, podding, and maturity stages. The cultivation pattern of no-tillage and direct-seeding after late rice harvest shortened the growth duration of rapeseed, especially at seedling stage, but prolonged the late budding stage in spring. The biomass accumulation from emergence to early budding was deficient severely, resulting in quick growth from budding to flowering of rapeseed. Application of N fertilizer had significant effects on enhancing the growth and yield formation of rapeseed through improving the individual and population qualities. Under the N rate of 270 kg ha−1 condition, the highest yield of rapeseed was approximately 2250 kg ha−1 at the density of 4.5 × 105 plants or 6.0 × 105 plants per hectare. The yield level was higher than that of average local rapeseed production. In the practice of no-tillage and direct seeding cultivation technique in the double rice cropping rice area, both nitrogen application rate and planting density should be considered simultaneously to obtain high quality of plant population and high yield of rapeseed.

In order to improve the performance of rotary MRF (MagnetoRheological Fluids) dampers, a calculation model of magneto-induced damping torque that is the controllable output of the dampers was introduced, the influences of the shape and size of the damper's working clearance on the magnetic field distribution and the output magneto-induced damping torque were analyzed according to the model. On the basis, a model for the optimal design of the working clearance was established. Taking the dampers with a constant clearance as benchmark and the maximum output magneto-induced damping torque as objective, iterative optimal design procedures were applied, under given condition, to the dampers with step- and wedge-shaped working clearances by means of the finite element analysis and structural optimization modules provided by ANSYS software. Experiments were also conducted. The experimental results conformed well with the optimal design results, which proved the validity of the models established for the torque calculation and clearance design optimization. Both the experimental and the optimal design results showed that the performance of the dampers with a step-shaped clearance is superior to the dampers with a constant clearance, and that the performance of the dampers with a wedge-shaped clearance is superior to the dampers with a step-shaped clearance.

In this paper, the heat generation principle of rotary MRF (MagnetoRheological Fluids) dampers was investigated, a mathematical model of heat source distribution was proposed, the temperature field caused by the heat sources was numerically simulated by means of ANSYS software, and the law of temperature distribution and rise was revealed. On the basis, a forced water-cooling system for the MRF dampers was designed to solve the temperature rise problem. Experiments were also conducted. Both numerical and experimental studies showed that, during the running of the dampers without any cooling measures being taken, the temperature of the dampers would continuously rise to a very high level before heat exchange balance was reached; while a forced water-cooling system was applied, the time for arriving at the heat exchange balance would be much shorter, and the temperature rise could be controlled within 20°C that is permissible for the practical application of the dampers.

In this study, the authors systematically evaluated the effect of low temperature stress on the germination of rapeseeds for 39 oilseed rape (Brassica napus L.) varieties. The results indicated a significant variation in the low temperature resistance of the seeds for different rape varieties. Using clustering method, various varieties were divided into different types, among which Huayouza No. 13, Fengyou 5103, Huayouza 95, Huayouza 62 and Fengyou 701 germinated well at low temperatures, while Zhongshuang No. 8 and Zhongshuang No. 11 showed poor germination. Correlation analysis was performed for 18 indices of seed germination, of which any two of germination percentage (GP), emergence percentage (EP), germination index (GI) and seedling vigour index (SVI) had high significant positive correlation, and they were all high significantly negatively correlated to the mean germination time (MGT). The GP was significantly negatively correlated with dry weight (DW). The MGT also showed a negative correlation with the root length (RL) and the total length (TL). The MGT had a statistically significant positive correlation with DW, and a negative correlation with shoot length (SL). Both the GI and SVI were significantly negatively correlated with DW. No correlation was observed between root to shoot length ratio (RL/SL) and any other index.