Strategija upravljanja pozicijom ultrazvučnog motora s putujućim valom

Since a conventional controller is continuous one, control period is normally set for a long time. When applying that controller for a travelling-wave ultrasonic motor whose parameters and performance are time-varying as a result of increasing temperature and operating condition, it is consequently resulted in degradation of the control performance. In this paper, a digital control algorithm is proposed for position control of the motors to shorten the long control period to maintain the stability of the motor performance. The proposed controller is digitally implemented by a SH7125 microcomputer utilizing a high-performance embedded workshop. The state quantities such as acceleration, speed and position, which are necessary for digital implementation, are provided by a rotary encoder. However, the optical encoder causes quantization errors in the speed information. To overcome the problem, a digital Variable Structure System (VSS) observer is also included to estimate the state quantities. The control input will be calculated after comparing the measured values and the estimated values given by the VSS observer. In short, a small, low cost and fast responsive digital controller is designed, based on a digital VSS observer, by using the SH7125 microcomputer. Effectiveness and reliability of the proposed digital controller are experimentally verified.Strategija upravljanja pozicijom ultrazvučnog motora s putujućim valom Sažetak: S obzirom da je standardni regulator najčešće kontinuirani, period upravljanja obično je postavljen na duži period. Koristeći takav regulator pri upravljanju ultrazvučnim motorom s putujućim valom, čiji su parametri i svojstva vremenski promjenjivi zbog povećanja temperature i promjena uvjeta rada, rezultat su smanjena upravljačka svojstva. U ovome radu predložen je digitalni upravljački algoritam za upravljanje pozicijom motora u svrhu smanjenja dugačkog perioda upravljanja za održavanje stabilnosti svojstava motora. Regulator je implementiran koristeći SH7125 mikroračunalo uz HEW (engl. high-performance embedded workshop) okruženje. Iznosi veličina kao što su akceleracija, brzina i pozicija, nužnih za digitalnu implementaciju, dobiveni su iz rotirajućeg enkodera. Međutim, optički enkoder dovodi do greške kvantizacije kod proračuna brzine. U svrhu smanjenja tog problema, u proces proračuna iznosa varijabli uključen je VSS (engl. Variable Structure System) estimator. Upravljački ulaz računa se nakon usporedbe mjerenih i estimiranih vrijednosti dobivenih korištenjem VSS-a. Dizajniran je digitalni regulator malih dimenzija, jeftine cijene i brzog odziva, temeljen na digitalnom VSS estimatoru koristeći SH7125 mikroračunalo. Eksperimentalno je provjerena efikasnost i pouzdanost digitalnog regulatora

TextANIMAR: Text-based 3D Animal Fine-Grained Retrieval

3D object retrieval is an important yet challenging task, which has drawn more and more attention in recent years. While existing approaches have made strides in addressing this issue, they are often limited to restricted settings such as image and sketch queries, which are often unfriendly interactions for common users. In order to overcome these limitations, this paper presents a novel SHREC challenge track focusing on text-based fine-grained retrieval of 3D animal models. Unlike previous SHREC challenge tracks, the proposed task is considerably more challenging, requiring participants to develop innovative approaches to tackle the problem of text-based retrieval. Despite the increased difficulty, we believe that this task has the potential to drive useful applications in practice and facilitate more intuitive interactions with 3D objects. Five groups participated in our competition, submitting a total of 114 runs. While the results obtained in our competition are satisfactory, we note that the challenges presented by this task are far from being fully solved. As such, we provide insights into potential areas for future research and improvements. We believe that we can help push the boundaries of 3D object retrieval and facilitate more user-friendly interactions via vision-language technologies.Comment: arXiv admin note: text overlap with arXiv:2304.0573

Jasmonates—the Master Regulator of Rice Development, Adaptation and Defense

Rice is one of the most important food crops worldwide, as well as the model plant in molecular studies on the cereals group. Many different biotic and abiotic agents often limit rice production and threaten food security. Understanding the molecular mechanism, by which the rice plant reacts and resists these constraints, is the key to improving rice production to meet the demand of an increasing population. The phytohormone jasmonic acid (JA) and related compounds, collectively called jasmonates, are key regulators in plant growth and development. They are also one of the central players in plant immunity against biotic attacks and adaptation to unfavorable environmental conditions. Here, we review the most recent knowledge about jasmonates signaling in the rice crop model. We highlight the functions of jasmonates signaling in many adaptive responses, and also in rice growth and development processes. We also draw special attention to different signaling modules that are controlled by jasmonates in rice

Modelling to support land and water management: experiences from the Mekong River Delta, Vietnam

By comparing the successful story of a hydrodynamic model (based on its contribution to policy changes, management options and livelihood improvement) with other modeling cases in the Mekong River Delta, five success factors are identified. These are (1) simulated phenomena relevant to and understandable by policy makers; (2) response to the needs of policy setting; (3) developed and handled by national modellers with direct links to the policy process; (4) availability of input data; and (5) long application history. These success factors provide higher opportunities for engaging modeling activities with policy setting

Aminopropyl Functionalised MCM-41: Synthesis and Application for Adsorption of Pb(II) and Cd(II)

This paper shows a comparison of porous properties of aminopropyl-MCM-41 materials functionalised via the direct and indirect methods. The obtained materials were characterised using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), adsorption/desorption isotherms of nitrogen, and Fourier-transfer infrared (FT-IR) spectroscopy. The results showed that the direct method provided the aminopropyl-MCM-41 material with well-ordered pores and high surface areas but with a lower quantity of grafted 3-aminopropyltriethoxysilane than the indirect method. To remove the organic template in the indirect method, solvent extraction with HCl/C2H5OH and calcination at 500°C were used, and the former gave a higher quantity of grafted 3-aminopropyltriethoxysilane in the resulting aminopropyl-MCM-41 materials. The experimental data were applied to the isotherm models of adsorption including Langmuir, Freundlich, Redlich–Peterson, and Sips either in the linear or nonlinear form. In order to avoid the bias of the determination coefficient and the error function method, the paired-samples t-test as an alternative method was first proposed to look for the most appropriate adsorption isotherms. The maximum adsorption capacity of Cd(II) and Pb(II) was 14.08 mg·g−1 and 64.21 mg·g−1, respectively. The mechanism of complexation and isoelectric interaction was suggested to explain the adsorption of Pb(II) and Cd(II) from aqueous solutions on aminopropyl functionalised MCM-41 in the range of pH from 2 to 9

CROWN ROOTLESS1 binds DNA with a relaxed specificity and activates OsROP and OsbHLH044 genes involved in crown root formation in rice

International audienceIn cereals, the root system is mainly composed of post-embryonic shoot-borne roots, named crown roots. The CROWN ROOTLESS1 (CRL1) transcription factor, belonging to the ASYMMETRIC LEAVES2-LIKE/LATERAL ORGAN BOUNDARIES DOMAIN (ASL/LBD) family, is a key regulator of crown root initiation in rice (Oryza sativa). Here, we show that CRL1 can bind, both in vitro and in vivo, not only the LBD-box, a DNA sequence recognized by several ASL/LBD transcription factors, but also another not previously identified DNA motif that was named CRL1-box. Using rice protoplast transient transactivation assays and a set of previously identified CRL1-regulated genes, we confirm that CRL1 transactivates these genes if they possess at least a CRL1-box or an LBD-box in their promoters. In planta, ChIP-qPCR experiments targeting two of these genes that include both a CRL1- and an LBD-box in their promoter show that CRL1 binds preferentially to the LBD-box in these promoter contexts. CRISPR/Cas9-targeted mutation of these two CRL1-regulated genes, which encode a plant Rho GTPase (OsROP) and a basic helix-loop-helix transcription factor (OsbHLH044), show that both promote crown root development. Finally, we show that OsbHLH044 represses a regulatory module, uncovering how CRL1 regulates specific processes during crown root formation