Parameter Estimation of Switched Hammerstein Systems

This paper deals with the parameter estimation problem of the Single-Input-Single-Output (SISO) switched Hammerstein system. Suppose that the switching law is arbitrary but can be observed online. All subsystems are parameterized and the Recursive Least Squares (RLS) algorithm is applied to estimate their parameters. To overcome the difficulty caused by coupling of data from different subsystems, the concept "intrinsic switch" is introduced. Two cases are considered: i) The input is taken to be a sequence of independent identically distributed (i.i.d.) random variables when identification is the only purpose; ii) A diminishingly excited signal is superimposed on the control when the adaptive control law is given. The strong consistency of the estimates in both cases is established and a simulation example is given to verify the theoretical analysis.Comment: 16 pages, 3 figures; Accepted for publication by Acta Mathematicae Applicatae Sinica (http://link.springer.com/journal/10255

Discrete mechanics Based on Finite Element Methods

Discrete Mechanics based on finite element methods is presented in this paper. We also explore the relationship between this discrete mechanics and Veselov discrete mechanics. High order discretizations are constructed in terms of high order interpolations.Comment: 14 pages, 0 figure

A comprehensive study of the dyes and dyeing methods for textiles excavated from a Qing tomb in Shijingshan District, Beijing

In this study, a group of textiles excavated from a Qing Dynasty tomb in Shijingshan District, Beijing, were studied in terms of their dyes and dyeing methods. Using ultra-high performance liquid chromatography, and pioneering in China detailed comparison with recorded historical dye recipes, and colors and dye compositions of some textiles handed down from ancient times, we identified sappanwood, Chinese cork tree, a dye containing ellagic acid (probably from acorn cup) and indigo. In most samples, one or two dyes were identified. Only a few samples might have been dyed with three or more dyes. Different color shades were obtained through the same combination of dyestuffs but different amounts of the dyestuffs. Comparison results show for the first time that the same dye was used for textiles of different types and materials, and threads for different uses. The dyes and dyeing methods used for this group of textiles are consistent with the historical records and with the analytical results of historical textiles. This study is also the first successful dye analysis of excavated textiles of the Qing Dynasty. These results supplement historical textile dyeing records, contributing to research on dyeing history of the Qing Dynasty

A comprehensive study of the dyes and dyeing methods for textiles excavated from a Qing tomb in Shijingshan District, Beijing

In this study, a group of textiles excavated from a Qing Dynasty tomb in Shijingshan District, Beijing, were studied in terms of their dyes and dyeing methods. Using ultra-high performance liquid chromatography, and pioneering in China detailed comparison with recorded historical dye recipes, and colors and dye compositions of some textiles handed down from ancient times, we identified sappanwood, Chinese cork tree, a dye containing ellagic acid (probably from acorn cup) and indigo. In most samples, one or two dyes were identified. Only a few samples might have been dyed with three or more dyes. Different color shades were obtained through the same combination of dyestuffs but different amounts of the dyestuffs. Comparison results show for the first time that the same dye was used for textiles of different types and materials, and threads for different uses. The dyes and dyeing methods used for this group of textiles are consistent with the historical records and with the analytical results of historical textiles. This study is also the first successful dye analysis of excavated textiles of the Qing Dynasty. These results supplement historical textile dyeing records, contributing to research on dyeing history of the Qing Dynasty

Specific Heat and Magnetic Properties of Ni-Mn-In Heusler Alloys

The recent discovery of giant magnetocaloric effects (MCE) at around room temperature has triggered the possibility of the development of a magnetic refrigerator that operates at ambient temperature. One of the main characteristics of giant magnetocaloric materials is the existence of a first order magnetic phase transition coupled with variations of the lattice parameter. This causes a huge entropy change which can be utilized practically. The martensitic transformation in these materials can be driven by either sweeping the magnetic field or the temperature and this property provides the flexibility to design thermodynamic cycles. Therefore, investigation of the entropy and the cooling power generated across this martensitic transition becomes important for practical purposes. However, the details of the correlation between the martensitic transition and magneto-elastic coupling in giant MCE materials have not been completely understood. Among new magnetocaloric materials, Ni-Mn-In Heusler alloys have attracted considerable attention as novel rare-earth free magnetic refrigerants. In order to fully understand the properties of the martensitic phase transition in Ni-Mn-In Heusler alloys and its influence on the MCE, we studied four well-characterized materials with nominal compositions Ni50Mn36In14, Ni50Mn35.5In14.5, Ni48Mn35In17 and Ni48Mn38In14, which differ in that the former two materials exhibit a paramagnetic to antiferromagnetic transition, whereas the others exhibit an additional ferromagnetic transition. We performed magnetization and field-dependent calorimetry measurements. The results provide a firm basis for the analytic evaluation of field-induced entropy changes and relative cooling power in these and related materials. We find that two of the samples (Ni50Mn36In14 and Ni50Mn35.5In14.5) include an additional entropy contribution beyond that due to magnetic spins due to the magneto-elastic coupling, which can be explained in terms of the renormalization of the phonon contributions. We also showed that the magnetization and calorimetry results give a consistent measure of antiferromagnetic plus superparamagnetic behavior of these materials to a model with Mn showing local moment behavior. The analysis provides a specific picture of the superparamagnetic properties of Ni50Mn36In14 and the spin canting behavior of Ni50Mn35.5In14.5. Further analysis of the relative cooling power provides a prediction which is shown to give a firm foundation for understanding the practical behavior of compositions with ferromagnetic and martensitic transformation nearly coinciding

Direct Measure of Giant Magnetocaloric Entropy Contributions in Ni-Mn-In

Off-stoichiometric alloys based on Ni 2 MnIn have drawn attention due to the coupled first order magnetic and structural transformations, and the large magnetocaloric entropy associated with the transformations. Here we describe calorimetric and magnetic studies of four compositions. The results provide a direct measure of entropy changes contributions including at the first-order phase transitions, and thereby a determination of the maximum field-induced entropy change corresponding to the giant magnetocaloric effect. We find a large excess entropy change, attributed to magneto-elastic coupling, but only in compositions with no ferromagnetic order in the high-temperature austenite phase. Furthermore, a molecular field model corresponding to antiferromagnetism of the low-temperature phases is in good agreement, and nearly independent of composition, despite significant differences in overall magnetic response of these materials

3D Question Answering

Visual Question Answering (VQA) has witnessed tremendous progress in recent years. However, most efforts only focus on the 2D image question answering tasks. In this paper, we present the first attempt at extending VQA to the 3D domain, which can facilitate artificial intelligence's perception of 3D real-world scenarios. Different from image based VQA, 3D Question Answering (3DQA) takes the color point cloud as input and requires both appearance and 3D geometry comprehension ability to answer the 3D-related questions. To this end, we propose a novel transformer-based 3DQA framework "3DQA-TR", which consists of two encoders for exploiting the appearance and geometry information, respectively. The multi-modal information of appearance, geometry, and the linguistic question can finally attend to each other via a 3D-Linguistic Bert to predict the target answers. To verify the effectiveness of our proposed 3DQA framework, we further develop the first 3DQA dataset "ScanQA", which builds on the ScanNet dataset and contains $\sim$6K questions, $\sim$30K answers for $806$ scenes. Extensive experiments on this dataset demonstrate the obvious superiority of our proposed 3DQA framework over existing VQA frameworks, and the effectiveness of our major designs. Our code and dataset will be made publicly available to facilitate the research in this direction.Comment: To Appear at IEEE Transactions on Visualization and Computer Graphics (TVCG) 202