Real-time unstructured road detection based on CNN and Gibbs energy function

Road detection algorithms with high robustness as well as timeliness are the basis for developing intelligent assisted driving systems. To improve the robustness as well as the timeliness of unstructured road detection, a new algorithm is proposed in this paper. First, for the first frame in the video, the homography matrix H is estimated based on the improved random sample consensus (RANSAC) algorithm for different regions in the image, and the features of H are automatically extracted using convolutional neural network (CNN), which in turn enables road detection. Secondly, in order to improve the rate of subsequent similar frame detection, the color as well as texture features of the road are extracted from the detection results of the first frame, and the corresponding Gaussian mixture models (GMMs) are constructed based on Orchard-Bouman, and then the Gibbs energy function is used to achieve road detection in subsequent frames. Finally, the above algorithm is verified in a real unstructured road scene, and the experimental results show that the algorithm is 98.4% accurate and can process 58 frames per second with 1024×960 pixels.

Volume Phase Transition in Gels: Its Discovery and Development

The history of volume phase transition of responsive gels from its theoretical prediction to experimental discovery was described and the major role of mixing Gibbs energy function in theoretical models was stressed. For detailed analysis and fine tuning of the volume phase transition, the generalized Flory–Huggins model with concentration and temperature dependent interaction function coupled with Maxwell construction as a tool is very suitable. Application of expansive stresses can uncover the potential of various swelling gels for volume phase transition. Experimentally, the abrupt, equilibrium-controlled phase transition is often hard to achieve due to passage of gel through states of mechanical instability and slow relaxation processes in macroscopic objects.

Effect of Thermal Vacancy on Thermodynamic Behaviors in BCC W Close to Melting Point: A Thermodynamic Study

As temperature increases, the thermal vacancy concentration in pure metals dramatically increases and causes some strongly non-linear thermodynamic behaviors in pure metals when close to their melting points. In this paper, we chose body-centered cubic (bcc) W as the target and presented a thermodynamic model to account for its Gibbs energy of pure bcc W from 0 K to melting point by including the contribution of thermal vacancy. A new formula for interaction part was proposed for describing the quadratic temperature behavior of vacancy formation energy. Based on the experimental/first-principles computed thermodynamic properties, all the parameters in the Gibbs energy function were assessed by following the proposed two-step optimization strategy. The thermodynamic behaviors, i.e., the strong nonlinear increase for temperature dependence of heat capacities at high temperatures and a nonlinear Arrhenius plot of vacancy concentration, in bcc W can be well reproduced by the obtained Gibbs energy. The successful description of thermal vacancy on such strongly non-linear thermodynamic behaviors in bcc W indicates that the presently proposed thermodynamic model and optimization strategy should be universal ones and are applicable to all other metals.

The Gibbs Energy Description of Nd:YAG System

Sublattice model is used to describe the complex system, Neodymium-doped yttrium aluminum garnet (Nd:YAG), and then Gibbs energy function of Nd:YAG system is seriously evaluated, mainly focusing on the instability of NAG, which has a direct effect on the Gibbs energy of NAG as well as Nd:YAG. Incorporating the selected literature thermochemical data of Nd:YAG system with the reevaluated parameters in Gibbs energy function according to a method utilized for defining the instability of NAG, the Gibbs energy function is well described. Trying to be more convincible, the method utilized for defining compounds stability and reevaluating the parameters has been test in Al2O3-Nd2O3, Al2O3-Y2O3, Al2O3-Gd2O3, Al2O3-Sm2O3 systems, achieving a satisfying agreement.

A Linear Mapping Hysteresis Model Based on Theory of Microscopic Polarization

In this paper, the underlying anhysteretic polarization is quantified through constitutive equations derived using Boltzmann statictics and Langevin model. The remanent polarization and the irreversible polarization are analyzed. A thermodynamic description of ferroelectric phenomena is proposed to address the coupling relations between electrical field and mechanical field by considering the series expansion of the elastic Gibbs energy function. A simple linear mapping hysteresis model based on theory of microscopic polarization is derived. In order to evaluate the effectiveness of the proposed model, a micro-positioning stage driven by the PZT in open-loop operation was used to test. The experimental results show that the proposed hysteresis model could precisely describe hysteresis phenomena. The fitting error is within 0.5%.

B2 Phases and their Defect Structures: Part I. Ab Initio Enthalpy of Formation and Enthalpy of Mixing in the Al-Ni-Pt-Ru System

ABSTRACTThe enthalpies of formation of the bcc phases in the Al-Ni-Pt-Ru system, particularly in the Al-Ru binary and Pt-Al-Ru ternary subsystems, were calculated by first principle methods. The enthalpies of formation for stoichiometric bcc-B2 phases have been calculated using both the GGA and LDA approximations, while the enthalpies of formation for B2 phases with large amounts of constitutional defects (both vacancies and anti-site atoms) were calculated using the Special Quasirandom Structures (SQS) approach. The enthalpies of mixing for the disordered bcc-A2 phases have also been calculated with SQS by mimicking the random bcc alloy with the local pair and multisite correlation functions. The calculated B2 lattice parameters for the different defect structures were compared with experimental results. These results are used as input values for the CALPHAD modified sublattice model to describe the A2/B2 phases with one Gibbs energy function.