New Viewpoints about Pseudo Measurements Method in Equality-Constrained State Estimation

We discuss the pseudo measurement method which is one of the main approaches to equality-constrained state estimation for a dynamic system. We demonstrate by the fundamental theory of Kalman filtering that reviewing the equality constraint as a pseudo measurement seems questionable. The main reason is that the additional pseudo measurement is actually a constant here which cannot help to estimate the state. More specifically, when the states in an unconstrained dynamic system model have already satisfied the equality constraint, the extra constraint is obviously not necessary. When the true equality-constrained states do not satisfy the unconstrained dynamic process equation, the effect of pseudo measurement is projecting the estimate which is not optimal onto the constraint set. However, since the performance of a projected estimate is also certainly influenced by its original estimate, we show through a numerical example that the pseudo measurement method is not always a good choice, especially when the process equation mismatch is large

PL-PatchSurfer: A Novel Molecular Local Surface-Based Method for Exploring Protein-Ligand Interactions

Structure-based computational methods have been widely used in exploring protein-ligand interactions, including predicting the binding ligands of a given protein based on their structural complementarity. Compared to other protein and ligand representations, the advantages of a surface representation include reduced sensitivity to subtle changes in the pocket and ligand conformation and fast search speed. Here we developed a novel method named PL-PatchSurfer (Protein-Ligand PatchSurfer). PL-PatchSurfer represents the protein binding pocket and the ligand molecular surface as a combination of segmented surface patches. Each patch is characterized by its geometrical shape and the electrostatic potential, which are represented using the 3D Zernike descriptor (3DZD). We first tested PL-PatchSurfer on binding ligand prediction and found it outperformed the pocket-similarity based ligand prediction program. We then optimized the search algorithm of PL-PatchSurfer using the PDBbind dataset. Finally, we explored the utility of applying PL-PatchSurfer to a larger and more diverse dataset and showed that PL-PatchSurfer was able to provide a high early enrichment for most of the targets. To the best of our knowledge, PL-PatchSurfer is the first surface patch-based method that treats ligand complementarity at protein binding sites. We believe that using a surface patch approach to better understand protein-ligand interactions has the potential to significantly enhance the design of new ligands for a wide array of drug-targets

Evidence of Kitaev interaction in the monolayer 1T-CrTe2_2

The two-dimensional 1T-CrTe$_2$ has been an attractive room-temperature van der Waals magnet which has a potential application in spintronic devices. Although it was recognized as a ferromagnetism in the past, the monolayer 1T-CrTe$_2$ was recently found to exhibit zigzag antiferromagnetism with the easy axis oriented at $70^\circ$ to the perpendicular direction of the plane. Therefore, the origin of the intricate anisotropic magnetic behavior therein is well worthy of thorough exploration. Here, by applying density functional theory with spin spiral method, we demonstrate that the Kitaev interaction, together with the single-ion anisotropy and other off-diagonal exchanges, is amenable to explain the magnetic orientation in the metallic 1T-CrTe$_2$. Moreover, the Ruderman-Kittle-Kasuya-Yosida interaction can also be extracted from the dispersion calculations, which explains the metallic behavior of 1T-CrTe$_2$. Our results demonstrate that 1T-CrTe$_2$ is potentially a rare metallic Kitaev material

Strong interlayer coupling in monoclinic GaTe

Recently, emerging intriguing physical properties have been unraveled in anisotropic layered semiconductors, with their in-plane anisotropy often originated directly from the low crystallographic symmetry. However, little has been known in the case where interlayer couplings dominate the anisotropy of electronic band structures in them. Here, by both experiment and theory, we show rather than geometric factors, the anisotropic energy bands of monoclinic gallium telluride (GaTe) are determined by a subtle bulk-surface interaction. Bulk electronic states are found to be the major contribution of the highest valence band, whose anisotropy is yet immune to surface doping of potassium atoms. The above peculiar behaviors are attributed to strong interlayer couplings, which gives rise to an inverse of anisotropy of hole effective masses and a direct-indirect-direct transition of band gap, depending on the number of layers. Our results thus pave the way for future applications of anisotropic layered semiconductors in nanoelectronics and optoelectronics.Comment: 3 figure

Cost-efficient Cooperative Video Caching Over Edge Networks

Cooperative caching has emerged as an efficient way to alleviate backhaul traffic and enhance user experience by proactively prefetching popular videos at the network edge. However, it is challenging to achieve the optimal design of video caching, sharing, and delivery within storage-limited edge networks due to the growing diversity of videos, unpredictable video requirements, and dynamic user preferences. To address this challenge, this work explores cost-efficient cooperative video caching via video compression techniques while considering unknown video popularity. First, we formulate the joint video caching, sharing, and delivery problem to capture a balance between user delay and system operative cost under unknown time-varying video popularity. To solve this problem, we develop a two-layer decentralized reinforcement learning algorithm, which effectively reduces the action space and tackles the coupling among video caching, sharing, and delivery decisions compared to the conventional algorithms. Specifically, the outer layer produces the optimal decisions for video caching and communication resource allocation by employing a multiagent deep deterministic policy gradient algorithm. Meanwhile, the optimal video sharing and computation resource allocation are determined in each agent’s inner layer using the alternating optimization algorithm. Numerical results show that the proposed algorithm outperforms benchmarks in terms of the cache hit rate, delay of users and system operative cost, and effectively strikes a tradeoff between system operative cost and users’ delay

Sm3+-Mn4+ activated Sr2GdTaO6 red phosphor for plant growth lighting and optical temperature sensing

Optical temperature sensing and plant growth lighting multifunctional applications can be realized by red luminescent materials. In this paper, novel Sm3+ and Sm3+-Mn4+ activated Sr2GdTaO6 (SGTO) red phosphors for plant growth and optical temperature sensing were comprehensively analyzed. The phase, luminescence property and thermal stability of the material were tested. For PL performance, SGTO:0.075Sm3+ exhibits the maximum emission intensity in the range (560–670 nm). The emission range of SGTO:0.075Sm3+ after introducing Mn4+ is mainly dark red light emission in the range from 630 to 750 nm, and the optimum dopingconcentration of Mn4+ is determined to be 0.3 %. The emission band of SGTO:0.075Sm3+ and SGTO:0.075Sm3+, 0.003Mn4+ matches the absorption band of the plants. For optical temperature sensing properties, the relative sensitivity (Sr) and absolute sensitivity (Sa) of SGTO:0.075Sm3+, 0.003Mn4+ are 2.94

Maternal ancestry analyses of red tilapia strains based on D-loop sequences of seven tilapia populations

Background Many tilapia species or varieties have been widely introduced and have become an economically important food fish in China. Information on the genetic backgrounds of these populations is deficient and requires more research, especially for red tilapia strains. Methods In the present study, displacement loop (D-loop) sequences were used to evaluate the genetic relationship and diversity of seven tilapia populations that are widely cultured in China; this was done specifically to speculate on the maternal ancestry of red tilapia strains. Three red tilapia varieties of Oreochromis ssp., Taiwan (TW), Israel (IL), and Malaysia (MY) strains and other populations, including O. aureus (AR), O. niloticus (NL), O. mossambicus (MS), and the GIFT strain of O. niloticus, were collected and analyzed in this study. Results A total of 146 polymorphic sites and 32 haplotypes of D-loop sequences were detected among 332 fish and four major haplotypes were shared among the populations. The TW and NL populations had a greater number of haplotypes (20 and 8, respectively). The haplotype diversity (Hd) and nucleotide diversity (π) of each population ranged from 0.234 to 0.826, and 0 to 0.060, respectively. The significant positive Tajima’s D value of neutral test were detected in the NL, IL, and MY populations (P  0.05). The nearest K2P genetic distance (D = 0.014) was detected between the MS and TW populations, whereas, the farthest (D = 0.101) was found between the GIFT and AR populations. The results from the molecular variance analysis (AMOVA) showed that there was an extremely significant genetic variation observed among the populations (P < 0.01), which contained 63.57% of the total variation. In view of the genetic relationship of red tilapia strains with other populations, TW and IL were detected with more similar genetic structures related to MS, and MY was more genetically similar to GIFT (or NL), which could provide more genetic evidence for the red tilapia strains maternal ancestry