A study of the effect of local scour on the flow field near the spur dike

The flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with time.In this study,large eddy simulations with fixed-bed at different scouring stages were conducted to investigate the changes in flow field.The results imply that the bed deformation leads to an increase in flow rate per unit area,which represent the capability of sediment transportation by water,in the scour hole.Moreover,the intensity of turbulent kinetic energy and bimodal motion near the sand bed induced by the HVS were also varied.However,the peak moments between the two sediment transport mechanisms were different.Hence,understanding the complex feedback mechanism between topography and flow field is essential for the local scour problem.

Combining Deep Learning with Knowledge Graph for Design Knowledge Acquisition in Conceptual Product Design

The acquisition of valuable design knowledge from massive fragmentary data is challenging for designers in conceptual product design.This study proposes a novel method for acquiring design knowledge by combining deep learning with knowledge graph.Specifically,the design knowledge acquisition method utilises the knowledge extraction model to extract design-related entities and relations from fragmentary data,and further constructs the knowledge graph to support design knowledge acquisition for conceptual product design.Moreover,the knowledge extraction model introduces ALBERT to solve memory limitation and communication overhead in the entity extraction module,and uses multi-granularity information to overcome segmentation errors and polysemy ambiguity in the relation extraction module.Experimental comparison verified the effectiveness and accuracy of the proposed knowledge extraction model.The case study demonstrated the feasibility of the knowledge graph construction with real fragmentary porcelain data and showed the capability to provide designers with interconnected and visualised design knowledge.

Preparation and Thermal Stability of AlMoON Based Solar Selective Absorption Coating

AlMoON based solar selective absorption coatings were deposited on stainless steel substrate by magnetron sputtering.The coatings included infrared reflection layer Mo,absorption layer AlMoN,absorption layer AlMoON and antireflection layer AlMoO from bottom to top.The surface of the deposited coatings is flat without obvious defects.The absorptivity and emissivity are 0.896 and 0.09,respectively,and the quality factor is 9.96.After heat treatment at 500℃-36 h,the surface roughness of the coating increases,a small number of cracks and other defects appear,and the broken part is still attached to the coating surface.A certain degree of element diffusion occurs in the coatings,resulting in the decline of the optical properties of the coatings.The absorptivity and emissivity are 0.883 and 0.131,respectively,the quality factor is 7.06,and the PC value is 0.0335.The coatings do not fail under this condition and have certain thermal stability.

Engineering Intelligent Racing Concepts Using Design Research Methods

The automotive seat market is positioned to significantly grow over the next five years. Research into how sensor implementation in every day driver cars can enhance driver wellness is becoming increasingly popular and visible in the automotive seat industry. However, in the competitive race car industry,?drivers prioritize driving ability over wellness. To further examine this phenomenon, the Human-Machine Interaction?Lab at the Georgia Institute of Technology took a unique approach to developing strong use cases for implementing sensor technology to improve driving ability for race car drivers by combining qualitative and quantitative research data obtained through modern design research and planning methodology. Following a process relying heavily on user-centered design methods, the authors developed a business case concept?for?a sensor-based seat accessory that acts as a competitive racer’s?driving coach?that is able to identify the mechanics of braking, turning, and accelerating through pressure sensors in the driver’s seat pan surface. This technology allows drivers to precisely understand when and how hard to brake, turn, or accelerate out of turns, thus reducing heat times and financial burden for drivers.

Aided innovative design of bathroom products based on artificial intelligence technology

Artificial intelligence technology, mainly refers to strengthening the artificial way, so as to combinecomputer technology with product design. Firstly, the auxiliary innovation of bathroomproducts based on artificial intelligence technology is proposed, then the user characteristicsare analysed, and the auxiliary design framework of bathroom products is designed. Finally, theinnovation model is established to realise the auxiliary innovation design of bathroom products.Experimental results show that the proposed method can effectively improve the interactionefficiency and response time, and reduce the false response.

Empirical mode decomposition using variable filtering with time scale calibrating

A novel and efficient method for decomposing a signal into a set of intrinsic mode functions （IMFs） and a trend is proposed. Unlike the original empirical mode decomposition （EMD）, which uses spline fits to extract variations from the signal by separating the local mean from the fluctuations in the decomposing process, this new method being proposed takes advantage of the theory of variable finite impulse response （FIR） filtering where filter coefficients and breakpoint frequencies can be adjusted to track any peak-to-peak time scale changes. The IMFs are results of a multiple variable frequency response FIR filtering when signals pass through the filters. Numerical examples validate that in contrast with the original EMD, the proposed method can fine-tune the frequency resolution and suppress the aliasing effectively.

自动驾驶汽车的产品服务系统设计空间初探

引语本文试图从产品服务系统的角度,探讨未来自动驾驶技术商业落地过程中的用户体验痛点,包括驾驶者注意力与活动的伴随自动驾驶技术升级而产生的变迁,和相应的设计考量因素。进而,我们提出了一个面向自动驾驶系统的交互设计空间,和相应的用户体验设计维度,试图为自动驾驶汽车交互设计和智能出行服务设计的新趋势提供行业思路借鉴。

Finite-element-analysis models for numerical simulation of partial discharges in spherical cavities within solid dielectrics:a review and a novel method

During the last two decades,partial discharges(PDs)modelling methods have been used as a complement of insulation diagnosis systems of electrical assets.Finite-element-analysis models for simulating PDs in cavities within solid dielectric materials are reviewed and a novel model is presented,which combines the main advantages of electrostatic and electric current models.The theoretical background is presented and some limitations and restrictions are discussed.A case of study was implemented for three different ageing conditions and simulation results exhibit good agreement with reported values by other authors in the literature.An analysis of variations of PD behaviour with ageing as a function of temperature and pressure is briefly presented.It is concluded that more research is needed to include physical and chemical interactions on the void surface and that the cavity surface conductivity plays a fundamental role in the PD simulations at advanced ageing conditions.

Improved deterministic and stochastic models for simulating partial discharges in non‐conducting trees inside solid dielectrics

Electrical trees are defects originated and driven by partial discharges(PD)activity and this is the reason why their modelling and simulation are fundamental for the ageing mechanisms comprehension and diagnosis analyses of insulation systems compound by solid dielectrics.This study presents a brief review of the different models implemented to simulate PD in electrical trees inside solid dielectrics.In addition,an improved deterministic model as well as a stochastic model are presented,which allow predicting adequately the PD pulses distribution,in magnitudes and phase,for non‐conducting electrical trees of different shape and length.Two case studies were simulated and their results exhibit good agreement when compared with measurements presented in the literature.It is concluded that the main parameters that state the PD behaviour in trees are the inception and extinction voltage mag-nitudes,including their probability distributions,and the tree geometry.The models can be used for prognosis analysis based on on‐line measurements.