Automatic navigation system for agricultural vehicles have become a widely used technology in precision agriculture over the last few decades. More and more sophisticated tractor control systems, however, revealed that exact positioning of the actual implement is equally or even more important. Based on literature sources and patent databases, the aim of this review is to introduce implement guidance systems and describe its current application in agricultural implement. Agricultural implement guidance is an essential technology for autonomous vehicle operations. In addition, applications and new technologies associated with navigation sensors on passive and active implement guidance are analyzed. Finally, challenges and future perspectives of agricultural implement systems are summarized and forecasted. This study can enrich the application of automatic navigation sensors on agricultural implements and provide a reference for the application of automatic navigation on more field operations.
In order to study the adsorption behavior of organic pollutants in sediment of the Yellow River in Lanzhou, p-hydroxy biphenyl (PHB) was selected as the typical organic pollutants to understand the adsorption kinetics and thermodynamics of PHB onto sediment of the Yellow River in Lanzhou based on the batch experiments. Meanwhile, the effects of systemic temperature, such as the particle size, the initial concentration of PHB, pH value, and the ionic strength, were also investigated for the adsorption of PHB onto sediment of the Yellow River. The results indicated that the adsorption kinetics of PHB onto sediment of the Yellow River could be better described by Pseudo-second-order model, and the boundary layer and intraparticle diffusion were both involved in the adsorption kinetic process. The adsorption thermodynamics of PHB onto sediment of the Yellow River were fitted well with the Langmuir model(R2>0.974), which was a single molecular layer adsorption process. The average adsorption free energy E ranged from 0.913 to 1.00 kJ·mol-1 when the systemic temperatures increased from 25℃ to 45℃, suggesting a physical adsorption. Thermodynamic parameter analysis indicated that Gibbs free energy (ΔGθ) and Entropy (ΔHθ) were less than zero, but Enthalpy (ΔSθ) was more than zero in the adsorption process, which tended to prove the spontaneous nature of the adsorption process, the endothermic nature of the adsorption process and the increased randomness at the sediment surface. Furthermore, the smaller the particle size, the greater the adsorption capacity of the PHB. The adsorption capacity was increased with the increase of the initial concentration of PHB. When the pH value in a range of 4.23 to 7.00, the adsorption capacity of PHB showed a slow decreasing trend, while the decreasing was sharp when pH value was greater than 7.00, and the adsorption capacity was almost zero when pH value was about 10.3. With the increase of ionic strength, the adsorption amount of PHB was also increased, but when the ionic strength increased to a certain value, due to the competitive adsorption, the adsorption of PHB onto sediments would be inhibited, resulting in decreased amount of adsorption.
Gait analysis is a simple and effective auxiliary diagnosis method for spinal diseases, and has achieved good results in the detection of Parkinson's symptoms and other medical diagnoses. Recently, gait-based assisted diagnosis of spinal diseases has received extensive attention in the research domain. Therefore, this paper studies the detection method of lumbar disc herniation based on patient gait data for auxiliary diagnosis of lumbar disc herniation. In order to obtain accurate gait features from video data efficiently, the human pose estimation tool OpenPose is used to preprocess the gait video data to obtain human key point sequence data. The gait features are quantized to form the vector representation of gait. According to the temporal characteristics of gait features, a TGAU model based on Transformer and gated attention unit(GAU) is proposed, where the GAU is used to effectively extract the features of gait data and reduce the influence of noise. Finally, we propose a model pre-training method based on transfer learning and use the open source OUMVLP-Pose gait recognition dataset to pretrain and fine-tune the model to enhance the performance. In order to verify the effectiveness of TGAU, we collect the gait video data of 10 patients with lumbar disc herniation and 11 normal people, obtain the gait analysis data through the proposed feature method. Experimental results show that our TGAU model gains higher accuracy than baselines, which demonstrate its effectiveness.
The graphic engine is very important in mobile game engine which effects the game's scene and the mobile's hardware.A MIDP 2.0 based on RPG engine is presented in this paper,including how to design,read,analysis,load and render the map-data-file.
Soil erosion is a severe environmental problem on the Loess Plateau, China. Vegetation restoration is the most efficient method to control soil erosion and introducing late-successional plant species may accelerate natural succession. However, the progress is affected by soil conditions and the appropriate thresholds of soil condition for seed addition are needed. Our objectives were to identify the vegetation types, examine the key soil factors affecting the vegetation variation, and determine the thresholds of the soil factors for each vegetation type. Five vegetation types in secondary succession were identified: association (assoc.) Artemisia scoparia assoc. Bothriochloa ischaemum assoc. Artemisia gmelinii Artemisia giraldii assoc. Ostryopsis davidiana Rubus parvifolius L., Syringa oblate and assoc. Sophora viciifolia Years since abandonment (YEAR), alkali-hydrolysable nitrogen (AHN), soil water content (SW), and total phosphorus (TP) were the key factors used to discriminate among vegetation types. Assoc. A. scoparia developed in croplands that had been abandoned for less than 11 years. Assoc. B. ischaemum developed in croplands abandoned for more than 11 years with lower soil nutrient levels (0.30 ≤ TP ≤ 0.646 g kg−1 and 16.72 ≤ AHN ≤ 32.62 mg kg−1). Assoc. A. gmelinii + A. giraldii always required greater TP (0.646 ≤ TP ≤ 0.79 g kg−1) to develop. When soil water content was lower (6.6 ≤ SW ≤ 8.4%), the assoc. S. viciifolia developed; otherwise, other associations, such as assoc. O. davidiana, developed. These soil thresholds can be used as references for guiding restoration, such as specifying proper soil conditions for seed sowing.
University Library is a main force to promote Agricultural Informatization and it plays a very important role in the realization of Agricultural Informatization,this thesis briefly introduces the advantages of University Library participation in Agricultural Informatization contruction,and the participation should be reinforced.
A survey was made on household telephones of 11 villages in 11 counties.The possession and utilization of both fixed telephones and mobile telephones were surveyed.The results have been analyzed and corresponding countermeasures have been put forward.
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