Active power filter control strategy with novel dual-repetitive controller and neural network adaptive PI control

U ovom je radu analizirana konfiguracija karakteristična za razdjelni aktivni filtar snage (SAPF) s dvodijelnim kondenzatorom kao i njegov glavni dijagram i upravljački modul. U svrhu poboljšanja dinamičke performanse upravljačkog sustava i pojačanja dinamičkog odziva, predstavljena je kombinirana strategija zasnovana na dvostruko-ponavljajućem kontrolnom uređaju (DRC) i adaptivnom PI upravljanju. U DRC-u jedan ponavljajući kontrolni uređaj je za osiguranje točnosti strujnog toka, a drugi za poboljšanje dinamičkog odziva. Prihvaćeno je PI upravljanje neuronskom mrežom da bi se poboljšala brzina odziva prilagođavanjem PI parametara, postavljajući parametre K\u27x i K\u27y online. Takva je strategija upravljanja primijenjena na simulaciju industrijskog prototipa i terensko ispitivanje. U usporedbi s uobičajenom strategijom upravljanja, eksperimentalni rezultat pokazuje da bi se kompenzacijom sustava mogle učinkovito smanjiti vrijednosti ukupne harmonijske distorzije (THD) od 26,02 %, 27,76 % i 27,60 % do 4,25 %, 4,57 % i 4,35 % za svaku fazu struje. A i puno vrijeme odziva je manje od 10 ms te u potpunosti zadovoljava standard IEEE-519.In this paper, the configuration characteristic of shunt active power filter (SAPF) with split-capacitor was analysed, as well as its principle diagram and control module. In order to improve the dynamic performance of a control system and elevate dynamic response, a combination strategy based on dual-repetitive controller (DRC) and adaptive PI control is presented. In DRC, one repetitive controller is for ensuring the current tracking accuracy and the other one is for enhancing dynamic response. The neural network PI control is adopted to improve response speed by turning the PI parameters adaptively, setting parameters K\u27x and K\u27y online. This control strategy was applied on industrial prototype simulation and field test. Comparing with the conventional control strategy, the experimental result shows that system compensation could effectively reduce the total harmonic distortion (THD) values from 26,02 %, 27,76 % and 27,60 % to 4,25 %, 4,57 % and 4,35 % for each phase of the current. And the full response time is all less than 10 ms, fully meeting the standard of IEEE-519

Vegetation greenness and photosynthetic phenology in response to climatic determinants

Vegetation phenology is a key indicator of vegetation-climate interactions and carbon sink changes in ecosystems. Therefore, it is very important to understand the temporal and spatial variability of vegetation phenology and the driving climatic determinants [e.g., temperature (Ts) and soil moisture (SM)]. Vegetation greenness and photosynthetic phenology were derived using the double logistic (DL) method to enhance vegetation index (EVI) and solar-induced chlorophyll fluorescence (SIF) spring and autumn phenology, respectively. The growing season length (GSL) of greenness phenology (about 100 days) derived EVI was longer than GSL of photosynthetic phenology (about 80 days) derived SIF. Although their overall spatiotemporal pattern trends were consistent, photosynthetic phenology varied 1.4 to 3.1 times more than greenness phenology over time. In addition, SIF-based photosynthetic phenology and EVI-based greenness phenology showed consistent factors of drivers but differed to some extent in spatial patterns and the most relevant preseason dates. Spring photosynthetic phenology was mainly influenced by pre-season mean cumulative Ts (about 90 days). However, greenness phenology was controlled by both pre-seasons mean cumulative Ts [(about 55 days) and mean cumulative SM (about 40 days)]. Autumn photosynthetic phenology was controlled by both periods’ mean cumulative Ts [(about 20 days) and SM (about 20 days)], but autumn greenness phenology was mainly influenced by pre-season mean cumulative Ts (85 days). The comparison analysis of SIF and EVI phenology helps to understand the difference between photosynthetic phenology and greenness phenology at a regional scale

Adjusting aggregation modes and photophysical and photovoltaic properties of diketopyrrolopyrrole-based small molecules by introducing B←N bonds

The packing mode of small-molecular semiconductors in thin films is an important factor that controls the performance of their optoelectronic devices. Designing and changing the packing mode by molecular engineering is challenging. Three structurally related diketopyrrolopyrrole (DPP)-based compounds were synthesized to study the effect of replacing C−C bonds by isoelectronic dipolar B←N bonds. By replacing one of the bridging C−C bonds on the peripheral fluorene units of the DPP molecules by a coordinative B←N bond and changing the B←N bond orientation, the optical absorption, fluorescence, and excited-state lifetime of the compounds can be tuned. The substitution alters the preferential aggregation of the molecules in the solid state from H-type (for C−C) to J-type (for B←N). Introducing B←N bonds thus provides a subtle way of controlling the packing mode. The photovoltaic properties of the compounds were evaluated in bulk heterojunctions with a fullerene acceptor and showed moderate performance as a consequence of suboptimal morphologies, bimolecular recombination, and triplet-state formation

Noncoding RNA in drug resistant sarcoma

Sarcomas are a group of malignant tumors that arise from mesenchymal origin. Despite significant development of multidisciplinary treatments for sarcoma, survival rates have reached a plateau. Chemotherapy has been extensively used for sarcoma treatment; however, the development of drug resistance is a major obstacle limiting the success of many anticancer agents. Sarcoma biology has traditionally focused on genomic and epigenomic deregulation of protein-coding genes to identify the therapeutic potential for reversing drug resistance. New and more creative approaches have found the involvement of noncoding RNAs, including microRNAs and long noncoding RNAs in drug resistant sarcoma. In this review, we discuss the current knowledge of noncoding RNAs characteristics and the regulated genes involved in drug resistant sarcoma, and focus on their therapeutic potential in the future

Experimental realization of a highly secure chaos communication under strong channel noise

A one-way coupled spatiotemporally chaotic map lattice is used to contruct cryptosystem. With the combinatorial applications of both chaotic computations and conventional algebraic operations, our system has optimal cryptographic properties much better than the separative applications of known chaotic and conventional methods. We have realized experiments to pratice duplex voice secure communications in realistic Wired Public Switched Telephone Network by applying our chaotic system and the system of Advanced Encryption Standard (AES), respectively, for cryptography. Our system can work stably against strong channel noise when AES fails to work.Comment: 15 pages, 5 figure

Structural and Electrical Properties of the YSZ/STO/YSZ Heterostructure

The heterostructure thin films of yttria-stabilized zirconia (YSZ)/strontium titanate (STO)/YSZ with various thicknesses were deposited on MgO single crystal substrate by pulsed laser deposition (PLD) method. The structural and electrical properties of the YSZ/STO/YSZ heterostructure were studied through X-ray diffraction (XRD) and electrical conductivity measurements. The in-plane conductivities of the thin films were measured and compared with that of the bulk sample. The highest conductivities were reported for those samples with the thinnest YSZ (220) layers. The observed enhancement in the lateral ionic conductivity was probably caused by the combination of the misfit dislocation density and elastic strain in the interfaces. The enhanced ionic mobility was discussed in terms of the disorder introduced in the oxygen sublattice through the epitaxial strain at the interfaces

Helicobacter pylori infection altered gastric microbiota in patients with chronic gastritis

ObjectiveThe present study aims to investigate the effect of Helicobacter pylori (Hp) infection on gastric mucosal microbiota in patients with chronic gastritis.MethodsHere recruited a population of 193 patients with both chronic gastritis and positive rapid urease, including 124 patients with chronic atrophic gastritis (CAG) and 69 patients with chronic non-atrophic gastritis (nCAG). Immunoblotting was used to detect four serum Hp antibodies (UreA, UreB, VacA and CagA) to determine the types of virulent Hp-I and avirulent Hp-II infections. Gastric microbiota was profiled by 16S rRNA gene V3-V4 region, and R software was used to present the relationship between the microbial characteristics and the type of Hp infection.ResultsIn the stomach of patients with Hp-positive gastritis, the dominant gastric bacterial genera included Ralstonia (23.94%), Helicobacter (20.28%), Pseudonocardia (9.99%), Mesorhizobium (9.21%), Bradyrhizobium (5.05%), and Labrys (4.75%). The proportion of Hp-I infection was significantly higher in CAG patients (91.1%) than in nCAG patients (71.0%) (P < 0.001). The gastric microbiota richness index (observed OTUs, Chao) was significantly lower in CAG patients than in nCAG patients (P <0.05). Compared with avirulent Hp-II infection, virulent Hp-I infection significantly decreased the Shannon index in CAG patients (P <0.05). In nCAG patients, Hp-I infected patients had lower abundances of several dominant gastric bacteria (Aliidiomarina, Reyranella, Halomonas, Pseudomonas, Acidovorax) than Hp-II infected patients. Meanwhile, in CAG patients, Hp-I infected patients occupied lower abundances of several dominant oral bacteria (Neisseria, Staphylococcus and Haemophilus) than Hp-II infected patients. In addition, bile reflux significantly promoted the colonization of dominant oral microbiota (Veillonella, Prevotella 7 and Rothia) in the stomach of CAG patients. There was no significant symbiotic relationship between Helicobacter bacteria and non-Helicobacter bacteria in the stomach of nCAG patients, while Helicobacter bacteria distinctly linked with the non-Helicobacter bacteria (Pseudolabrys, Ralstonia, Bradyrhizobium, Mesorhizobium and Variovorax) in CAG patients.ConclusionsVirulent Hp infection alters the gastric microbiota, reduces microbial diversity, and enhances the symbiotic relationship between the Helicobacter bacteria and non-Helicobacter bacteria in patients with chronic gastritis. The data provides new evidence for treating Hp infection by improving the gastric microbiota

Manufacturer’s Sharing Servitization Transformation and Product Pricing Strategy

The sharing market includes the idle product sharing by the owner and the firm’s new product sharing. Companies participating in the sharing economy choose to withdraw from the market because it is always difficult to make a profit, due to heavy asset investment, but there is no such worry for owners who do not need cost input. At the same time, we have observed that the sharing products launched by companies are difficult to meet the rental needs of consumers. Based on the above findings, we have constructed a model where there is a market where a monopolistic manufacturer sells and rents out at the same time, and owners who purchased new products can choose to rent out products when they are idle. Because of the uncoordinated supply and demand matching of the sharing market and the excessively high unit cost input, our research found that: (1) the barriers for the manufacturer to enter the sharing market are always high—for example, the manufacturer will choose to enter the sharing market only when consumers have a high rate of availability of sharing products. Only when the cost of products in the sharing market is not low will the manufacturer choose to provide sharing services; (2) the competition between the two products in the sharing market weakens the demand cannibalize in the sales market; (3) the manufacturer enters the sharing market to promote the owner’s income. The owner’s earnings will increase with the rising of sharing products’ availability