68 research outputs found
Research on the Electromagnetic-Heat-Flow Coupled Modeling and Analysis for In-Wheel Motor
In this paper, a 15 KW in-wheel motor (IWM) is taken as the research object, and the coupling factors among the electromagnetic field, temperature field and flow field are analyzed, and the strong and weak coupling factors between the three fields are clarified, and by identifying the strong and weak coupling factors between the three fields, a three-field coupling analysis model for IWM with appropriate complexity is established, and the validity of the model is verified. In a certain driving condition, the electromagnetic field, temperature field and flow field characteristics of IWM are analyzed with the multi-field coupling model. The result shows that, after the IWM runs 8440 s under driving conditions, in this paper, the IWM electromagnetic torque of the rated working condition is 134.2 Nm, and IWM the electromagnetic torque of the peak working condition is 451.36 Nm, and the power requirement of the motor can be guaranteed. The highest temperature of the IWM is 150 °
C, which does not exceed the insulation grade requirements of the motor (155 °
C), the highest temperature of the permanent magnet (PM) is 65.6 °
C, and it does not exceed the highest operating temperature of the PM, and ensures the accurate calculation of components loss and the temperature of the motor. It can be found, through research, that the electromagnetic torque difference between unidirectional coupling and bidirectional coupling is 3.2%, the maximum temperature difference is 7.98% in the three-field coupling analysis of IWM under rated working conditions. Therefore, it is necessary to consider the influence of coupling factors on the properties of motor materials when analyzing the electromagnetic field, temperature field and flow field of IWM
it also provides some reference value for the simulation analysis of IWM in the future.
Document type: Articl
A deep learning model for drug screening and evaluation in bladder cancer organoids
Three-dimensional cell tissue culture, which produces biological structures termed organoids, has rapidly promoted the progress of biological research, including basic research, drug discovery, and regenerative medicine. However, due to the lack of algorithms and software, analysis of organoid growth is labor intensive and time-consuming. Currently it requires individual measurements using software such as ImageJ, leading to low screening efficiency when used for a high throughput screen. To solve this problem, we developed a bladder cancer organoid culture system, generated microscopic images, and developed a novel automatic image segmentation model, AU2Net (Attention and Cross U2Net). Using a dataset of two hundred images from growing organoids (day1 to day 7) and organoids with or without drug treatment, our model applies deep learning technology for image segmentation. To further improve the accuracy of model prediction, a variety of methods are integrated to improve the model’s specificity, including adding Grouping Cross Merge (GCM) modules at the model’s jump joints to strengthen the model’s feature information. After feature information acquisition, a residual attentional gate (RAG) is added to suppress unnecessary feature propagation and improve the precision of organoids segmentation by establishing rich context-dependent models for local features. Experimental results show that each optimization scheme can significantly improve model performance. The sensitivity, specificity, and F1-Score of the ACU2Net model reached 94.81%, 88.50%, and 91.54% respectively, which exceed those of U-Net, Attention U-Net, and other available network models. Together, this novel ACU2Net model can provide more accurate segmentation results from organoid images and can improve the efficiency of drug screening evaluation using organoids
Different responses of soil fungal and bacterial communities to nitrogen addition in a forest grassland ecotone
IntroductionContinuous nitrogen deposition increases the nitrogen content of terrestrial ecosystem and affects the geochemical cycle of soil nitrogen. Forest-grassland ecotone is the interface area of forest and grassland and is sensitive to global climate change. However, the structure composition and diversity of soil microbial communities and their relationship with soil environmental factors at increasing nitrogen deposition have not been sufficiently studied in forest-grassland ecotone.MethodsIn this study, experiments were carried out with four nitrogen addition treatments (0 kgN·hm−2·a−1, 10 kgN·hm−2·a−1, 20 kgN·hm−2·a−1 and 40 kgN·hm−2·a−1) to simulate nitrogen deposition in a forest-grassland ecotone in northwest Liaoning Province, China. High-throughput sequencing and qPCR technologies were used to analyze the composition, structure, and diversity characteristics of the soil microbial communities under different levels of nitrogen addition.Results and discussionThe results showed that soil pH decreased significantly at increasing nitrogen concentrations, and the total nitrogen and ammonium nitrogen contents first increased and then decreased, which were significantly higher in the N10 treatment than in other treatments (N:0.32 ~ 0.48 g/kg; NH4+-N: 11.54 ~ 13 mg/kg). With the increase in nitrogen concentration, the net nitrogen mineralization, nitrification, and ammoniation rates decreased. The addition of nitrogen had no significant effect on the diversity and structure of the fungal community, while the diversity of the bacterial community decreased significantly at increasing nitrogen concentrations. Ascomycetes and Actinomycetes were the dominant fungal and bacterial phyla, respectively. The relative abundance of Ascomycetes was negatively correlated with total nitrogen content, while that of Actinomycetes was positively correlated with soil pH. The fungal community diversity was significantly negatively correlated with nitrate nitrogen, while the diversity of the bacterial community was significantly positively correlated with soil pH. No significant differences in the abundance of functional genes related to soil nitrogen transformations under the different treatments were observed. Overall, the distribution pattern and driving factors were different in soil microbial communities in a forest-grassland ecotone in northwest Liaoning. Our study enriches research content related to factors that affect the forest-grassland ecotone
Caged molecular beacons: controlling nucleic acid hybridization with light
We have constructed a novel class of light-activatable caged molecular beacons (cMBs) that are caged by locking two stems with a photo-labile biomolecular interaction or covalent bond. With the cMBs, the nucleic acid hybridization process can be easily controlled with light, which offers the possibility for a high spatiotemporal resolution study of intracellular mRNAs.NSFC[20805038, 21075104]; MOE[200803841013]; National Basic Research Program of China[2007CB935603, 2010CB732402]; National Key Scientific Program of China[2011CB911000]; China National Grand Program on Key Infectious Disease[2009ZX10004-312]; NIH; Procter and Gambl
Altered effective connectivity and anomalous anatomy in the basal ganglia-thalamocortical circuit of stuttering speakers
A secure user authentication protocol for sensor network in data capturing
Sensor network is an important approach of data capturing. User authentication is a critical security issue for sensor networks because sensor nodes are deployed in an open and unattended environment, leaving them possible hostile attack. Some researchers proposed some user authentication protocols using one-way hash function or using biometric technology. Recently, Yel et al. and Wenbo et al. proposed a user authentication protocols using elliptic curves cryptography. However, there are some security weaknesses for these protocols. In the paper, we review several proposed user authentication protocols, with a detail review of the Wenbo et al.’s user authentication protocol and a cryptanalysis of this protocol that shows several security weaknesses. Furthermore, we propose a secure user authentication protocol using identity-based cryptography to overcome those weaknesses. Finally, we present the security analysis, a comparison of security, computation, and performance for the proposed protocols, which shows that this user authentication protocol is more secure and suitable for higher security WSNs
Design of material flow sensor based on electric field inductio
In view of the problem that existing switch type and pressure type material flow sensors are easy to wear and have poor reliability,a kind of material flow sensor based on electric field induction was designed. The sensor adopts smart chip with built-in electric field induction as sensing element to monitor electric parameters of electric field, and uses single-chip microcomputer to collect and process electric parameters of electric field, and output signals indicating whether there are material on the belt through change of electrical parameters and internal data processing. The field test results show that the sensor can accurately detect material on moving or stationary belt, meets needs of practical application, which has characteristics of non-contact detection, no wear, long life, stable and reliable signal
An Experimental Study of a New Channel for Data Input on Small Mobile Devices
Data input on small devices can be difficult because of the limited size of the interface. Built-in sensors bring alternatives for user input on small devices. We propose to use device tilt positions to represent data input. The built-in accelerometers are used to derive the tilt positions. The combinations of tilt positions are mapped to characters and commands. Users conduct data input by tilting the device to dedicated positions consecutively and clicking a button to confirm an operation. Feedback is audible so that the display is not required. Hence this tilt-click positioning input mechanism is onehanded and eyes-free. In this paper, we present two positioning input systems using five positions and nine positions respectively. Two experiments are conducted showing that novice users achieved 2.8 WPM (words per minute) with audible feedback in text input, and 33.4 SPC (seconds per calculation) with audible feedback for five digit calculations
Tilt-click: One-handed eyes-free numeric and symbol input for calculator applications
Tilt operations with audio feedback can enable data input using handheld device, single handed and eyes free. This paper presents a prototype using 5 tilt positions for numeric and symbol input for calculator applications. Two tilt positions are mapped into a single digit or one operation symbol. Users click one physical key to indicate a tilt position and hear audio feedback. Controlled experiments showed that the tilt-click input technique is feasible and promising for small mobile devices. © 2012 IEEE
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