This article proposes a robust model predictive control (MPC) algorithm for the tracking problem of wheeled mobile robots. The robots are subject to bounded disturbances and various practical ...constraints. Particularly, the incremental input constraint is introduced in the consideration of the safety and comfortability needs in real life. Conditions on the acceleration of the leader robot are derived to guarantee the satisfaction of the incremental input constraint of follower robot. To compensate for the effect of disturbances, a disturbance observer is designed to obtain the estimation of the disturbances, which together with the optimal control input of MPC optimization is contained in the actual control input. Also, a novel quadratic robustness constraint is developed to handle the disturbance estimation error, which allows the designer to balance the initial feasible region and control performance. The proposed algorithm can ensure recursive feasibility, robust constraint satisfaction, and closed-loop stability. Finally, both simulation and experiment results are provided to verify the theoretical properties.
This article presents a method of sequence-to-sequence (seq2seq) voice conversion using non-parallel training data. In this method, disentangled linguistic and speaker representations are extracted ...from acoustic features, and voice conversion is achieved by preserving the linguistic representations of source utterances while replacing the speaker representations with the target ones. Our model is built under the framework of encoder-decoder neural networks. A recognition encoder is designed to learn the disentangled linguistic representations with two strategies. First, phoneme transcriptions of training data are introduced to provide the references for leaning linguistic representations of audio signals. Second, an adversarial training strategy is employed to further wipe out speaker information from the linguistic representations. Meanwhile, speaker representations are extracted from audio signals by a speaker encoder. The model parameters are estimated by two-stage training, including a pre-training stage using a multi-speaker dataset and a fine-tuning stage using the dataset of a specific conversion pair. Since both the recognition encoder and the decoder for recovering acoustic features are seq2seq neural networks, there are no constrains of frame alignment and frame-by-frame conversion in our proposed method. Experimental results showed that our method obtained higher similarity and naturalness than the best non-parallel voice conversion method in Voice Conversion Challenge 2018. Besides, the performance of our proposed method was closed to the state-of-the-art parallel seq2seq voice conversion method.
•Mafic magmatism above oceanic and continental subduction zones proceeds in two-stage processes.•Crustal signatures are transferred by liquid phases into the mantle source of mafic igneous rocks.•The ...fractionation of melt-mobile trace elements is significant at the slab-mantle interface.•Metasomatism is the physicochemical mechanism for the geochemical transfer in subduction zones.•The melting of rocks is dictated by the thermal structure of subduction zones at different depths.
The geochemical signatures of subducting crust have been identified in various types of mafic igneous rocks at convergent plate boundaries, where island arc basalts (IAB) and continental arc andesite are accepted as the typical products of subduction zone magmatism. These crustal signatures are commonly represented not only by enrichment in large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to normal mid-ocean ridge basalts (MORB), but also by enrichment in radiogenic Sr isotopes but depletion in radiogenic Nd isotopes relative to the primitive mantle. Such enriched signatures also occur in oceanic island basalts (OIB) and their continental counterparts, but their origin has been controversial in igneous petrology. The present review focuses on the origin of enriched signatures in mafic igneous rocks above subduction zones. Although these mafic rocks are distributed in both interplate and intraplate areas, they are generally categorized into two series according to their trace element distribution patterns in the primitive mantle-normalized diagram. One is IAB-like series, showing enrichment in LILE, Pb and LREE but depletion in high field strength elements (HFSE) such as Nb and Ta relative to heavy rare earth elements (HREE). The other is OIB-like series, exhibiting enrichment in LILE and LREE, enrichment or non-depletion in HFSE but depletion in Pb relative to HREE. In either series, these mafic igneous rocks show enhanced enrichment of LILE and LREE with increasing their incompatibility relative to normal MORB, indicating the presence of crustal materials in these mafic igneous rocks. Inspection of the mass balance in major and trace elements between source and product indicates that subducting crustal rocks were not directly incorporated into the mantle sources of both series. Instead, they underwent metamorphic dehydration and partial melting at different depths to produce liquid phases, which dominate the budget of fluid- to melt-mobile elements and their pertinent radiogenic isotopes in the mantle sources. As a consequence, the composition of liquid phases is a key to the geochemical composition of both series. Therefore, the crustal materials are transferred by the liquid phases via metasomatic reactions into the mantle sources at the slab-mantle interface in subduction channels. As such, the difference in the geochemical transfer from the subducting crust into the mantle can account for the difference in the composition between the interplate IAB-like and intraplate OIB-like series. This provides a holistic model for the origin of both IAB- and OIB-like series mafic igneous rocks above subduction zones.
Albuvirtide is a once-weekly injectable human immunodeficiency virus (HIV)-1 fusion inhibitor. We present interim data for a phase 3 trial assessing the safety and efficacy of albuvirtide plus ...lopinavir-ritonavir in HIV-1-infected adults already treated with antiretroviral drugs.
We carried out a 48-week, randomized, controlled, open-label non-inferiority trial at 12 sites in China. Adults on the World Health Organization (WHO)-recommended first-line treatment for >6 months with a plasma viral load >1000 copies/mL were enrolled and randomly assigned (1:1) to receive albuvirtide (once weekly) plus ritonavir-boosted lopinavir (ABT group) or the WHO-recommended second-line treatment (NRTI group). The primary endpoint was the proportion of patients with a plasma viral load below 50 copies/mL at 48 weeks. Non-inferiority was prespecified with a margin of 12%.
At the time of analysis, week 24 data were available for 83 and 92 patients, and week 48 data were available for 46 and 50 patients in the albuvirtide and NRTI groups, respectively. At 48 weeks, 80.4% of patients in the ABT group and 66.0% of those in the NRTI group had HIV-1 RNA levels below 50 copies/mL, meeting the criteria for non-inferiority. For the per-protocol population, the superiority of albuvirtide over NRTI was demonstrated. The frequency of grade 3 to 4 adverse events was similar in the two groups; the most common adverse events were diarrhea, upper respiratory tract infections, and grade 3 to 4 increases in triglyceride concentration. Renal function was significantly more impaired at 12 weeks in the patients of the NRTI group who received tenofovir disoproxil fumarate than in those of the ABT group.
The TALENT study is the first phase 3 trial of an injectable long-acting HIV drug. This interim analysis indicates that once-weekly albuvirtide in combination with ritonavir-boosted lopinavir is well tolerated and non-inferior to the WHO-recommended second-line regimen in patients with first-line treatment failure.
ClinicalTrials.gov Identifier: NCT02369965; https://www.clinicaltrials.gov.Chinese Clinical Trial Registry No. ChiCTR-TRC-14004276; http://www.chictr.org.cn/enindex.aspx.
The pursuit of synthetic receptors with high binding affinities has long been a central focus in supramolecular chemistry, driven by their significant practical relevance in various fields. Despite ...the numerous synthetic receptors that have been developed, most exhibit binding affinities in the micromolar range or lower. Only a few exceptional receptors achieve binding affinities exceeding 109 M−1, and their substrate scopes remain rather limited. In this context, we introduce SC5A, a conjugated corral‐shaped macrocycle functionalized with ten sulfate groups. Owing to its deep one‐dimensional confined hydrophobic cavity and multiple sulfate groups, SC5A displays an extraordinarily high binding strength of up to 1011 M−1 towards several size‐matched, rod‐shaped organic dications in water. Besides, its conformation exhibits good adaptability, allowing it to encapsulate a wide range of other guests with diverse molecular sizes, shapes, and functionalities, exhibiting relatively strong affinities (Ka=106–108 M−1). Additionally, we've explored the preliminary application of SC5A in alleviating blood coagulation induced by hexadimethrine bromide in vitro and in vivo. Therefore, the combination of ultrahigh binding affinities (towards complementary guests) and adaptive recognition capability (towards a wide range of functional guests) of SC5A positions it as exceptionally valuable for numerous practical applications.
A new water‐soluble corral‐shaped conjugated host bearing ten sulfate groups at its two rims—namely, SC5A—was synthesized. SC5A not only exhibited ultrahigh binding affinities (up to 1011 M−1) towards a series of rod‐shaped substrates, but also effectively bound (Ka=106–108 M−1) a wide range of functional substrates. Additionally, the application of SC5A in alleviating blood coagulation induced by hexadimethrine bromide was explored.
The precise recognition and sensing of steroids, a type of vital biomolecules, hold immense practical value across various domains. In this study, we introduced corral4BINOLs (C4BINOLs), a pair of ...enantiomeric conjugated deep‐cavity hosts, as novel synthetic receptors for binding steroids. Due to the strong hydrophobic effect of their deep nonpolar, chiral cavities, the two enantiomers of C4BINOLs demonstrated exceptionally high recognition affinities (up to 1012 M−1) for 16 important steroidal compounds as well as good enantioselectiviy (up to 15.5) in aqueous solutions, establishing them as the most potent known steroid receptors. Harnessing their ultrahigh affinity, remarkable enantioselectivity, and fluorescence emission properties, the two C4BINOL enantiomers were employed to compose a fluorescent sensor array which achieved discrimination and sensing of 16 structurally similar steroids at low concentrations.
A pair of enantiomeric macrocycles, RRRR‐ and SSSS‐C4BINOL, demonstrated exceptionally high recognition affinities (up to 1012 M−1) towards 16 important steroidal compounds in aqueous solutions, establishing them the most effective known steroid receptors. The two C4BINOL enantiomers were employed to compose a fluorescent sensor array which achieved discrimination and sensing of 16 structurally similar steroids in biofluids.
This article examines how to accurately measure yarn density for 3-D braided composite preforms in large images. However, due to the complex structure and dense yarns of the preform, there is a lack ...of effective methods to solve this problem in practical applications. In the end, the task of yarn density measurement is mainly performed by experienced operators. They usually use a ruler to measure the distance between a fixed number of fabrics to calculate density, which is time-consuming and subjective. Therefore, an effective and efficient method for yarn density measurement of 3-D braided composite preforms is demanded. To address this problem, we propose a novel framework combining deep learning with traditional image processing techniques to measure yarn density automatically. First, to ensure the accuracy of yarn detection, we obtain a high-resolution raw image of <inline-formula> <tex-math notation="LaTeX">2448\times2048 </tex-math></inline-formula>. The preprocessed images are then fed into our Yarn Detection Network (YDNet) based on the rotation object detection method to detect per segmented yarn. To achieve this, we propose a dilated feature network (DFN) that can obtain features at different scales and improve detection speed. Then, the feature alignment module (FAM) is introduced to achieve higher detection accuracy. Moreover, we design a Yarn Loss (YLoss) to detect yarn boxes more accurately via considering the aspect ratio of the yarns as an important parameter. Then, we design a multilevel rotation mechanism based on the extracted yarns to correct the image and calculate the yarn density accurately. We conduct several experiments to verify the superiority of our proposed YDNet, and the accuracy and effectiveness of the proposed framework for the automatic yarn density measurement. The experimental results show that our method is superior to other state-of-the-art methods.
Prader-Willi syndrome (PWS) is a rare and multisystemic genetic disorder that is characterized by severe hypotonia, hyperphagia, short stature, and global developmental delay. Although early ...recombinant human growth hormone (rhGH) treatment has been proven to rescue some symptoms and bring additional benefits to PWS patients, studies in patients under 2 years old are scarce. Thus, this study aims to investigate the effectiveness and safety of rhGH treatment for young children.
A total of 96 genetically confirmed Chinese PWS infants or toddlers (47 males) followed between 2013 and 2022 were retrospectively analyzed. Sixty-five infants (early treatment group) started rhGH treatment during their first year, and 31 toddlers (later treatment group) started at the age of 1-2 years. Auxological parameters, carbohydrate metabolism parameters, thyroid function, liver function, insulin-like growth factor-1 (IGF-1), and radiographs were acquired before the initiation of the treatment and every 3-6 months thereafter. Height/length, weight, and weight for height were expressed as standard deviation scores (SDSs) according to WHO child growth standards.
The mean SDS of length/height in the early treatment group was significantly higher than that in the later treatment group throughout the observation period (all P < 0.001). The change in the length SDS between the two groups at 1 year old and 4 years old was 1.50 (95% CI, 0.88-2.13) and 0.63 (95% CI, 0.16-1.10), respectively. Compared to the later treatment group, the weight SDS in the early treatment group increased by 0.94 (95% CI, 0.37-1.52) at 1 year old and 0.84 (95% CI, 0.28-1.39) at 2 years old. No statistical significance was found after 2.5 years of age. No significant differences were observed in IGF-1, incidence of liver dysfunction, hypothyroidism or spinal deformity between the two groups.
rhGH treatment improved growth and body composition in infants and toddlers. Furthermore, an early start of rhGH treatment is expected to have more efficacy than the later treatment group without an increase in adverse effects.
Purpose
Conventional wisdom suggests that war in the host country makes it unattractive for foreign firms to invest. To see if this is true for US firms on the aggregate, this paper aims to examine ...the veracity of a “permanent war economy” hypothesis, that foreign direct investment (FDI) may, in fact, increase in the host country not despite, but because of, war, i.e. one that lends credence to the idea that, in the USA, “defense has become one of constant preparation for future wars and foreign interventions rather than an exercise in response to one-off threats.”
Design/methodology/approach
The authors test the hypotheses using Generalized Method of Moments estimation, with Heckman Selection, on US FDI data from the Bureau of Economic Analysis and war data from the Correlates of War2 Project, the Uppsala Conflict Data Program/International Peace Research Institute data set, the International Crisis Behavior Project and the Center for Systemic Peace Major Episodes of Political Violence data set. The final sample consists of 351 country-year observations in 55 host countries from 1982 to 2006.
Findings
The findings indicate that overall US FDI in a host country in a given year decreases if the host country is engaged in wars with multiple countries and if the US Government is involved in the war. Most notably, the results show that US involvement in multiple host country wars is actually correlated with increased US FDI into the host country, providing empirical support for the “permanent war economy” hypothesis.
Originality/value
While other studies have focused on war and FDI, the authors have sought to show the impact of the involvement of arguably the most influential country, i.e. the USA, in the sovereign matters of a focal host country. By studying FDI from the USA as a function of US involvement in wars overseas, over the years with the greatest use of private military companies by the USA and the largest portion of global FDI accounted for by the USA, this work motivates a research agenda on home-host-"other” relations in the context of war and FDI, with the “other” being the supranational “elephant in the room.”
Bridged indoline derivatives were synthesized by an intermolecular Pd‐catalyzed allylic dearomatization reaction of substituted indoles. The reaction between indoles and allyl carbonates bearing a ...nucleophilic alcohol side‐chain proceeds in a cascade fashion, providing bridged indolines in excellent enantioselectivity.
Bridged indoline derivatives were synthesized by an intermolecular Pd‐catalyzed allylic dearomatization reaction of substituted indoles. The reaction between indoles and allyl carbonates bearing a nucleophilic alcohol side‐chain proceeds in a cascade fashion, providing bridged indolines with excellent enantioselectivity.
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