Fixed-Time Convergent Distributed Observer Design of Linear Systems: A Kernel-Based Approach

The robust distributed state estimation for a class of continuous-time linear time-invariant systems is achieved by a novel kernel-based distributed observer, which, for the first time, ensures fixed-time convergence properties. The communication network between the agents is prescribed by a directed graph in which each node involves a fixed-time convergent estimator. The local observer estimates and broadcasts the observable states among neighbours so that the full state vector can be recovered at each node and the estimation error reaches zero after a predefined fixed time in the absence of perturbation. This represents a new distributed estimation framework that enables faster convergence speed and further reduced information exchange compared to a conventional Luenberger-like approach. The ubiquitous timevarying communication delay across the network is suitably compensated by a prediction scheme. Moreover, the robustness of the algorithm in the presence of bounded measurement and process noise is characterised. Numerical simulations and comparisons demonstrate the effectiveness of the observer and its advantages over the existing methods

technical report for projects TIGA and SEAL

repor

1-[4-(4-Chloro­but­oxy)-2-hy­droxy­phen­yl]ethanone

In the title compound, C12H15ClO3, the eth­oxy group is nearly coplanar with the benzene ring, making a dihedral angle of 9.03 (4)°, and is involved in an intra­molecular O—H⋯O hydrogen bond to the neighbouring hy­droxy group

[μ-1,4-Bis(1,2,4-triazol-1-ylmeth­yl)benzene]­bis­[aqua­(pyridine-2,6-dicarboxyl­ato)copper(II)] monohydrate

The title compound, [Cu2(C7H3NO4)2(C12H12N6)(H2O)2]·H2O, displays a discrete dinuclear structure, in which the central CuII atom is five-coordinated in a distorted square-based pyramidal coordination geometry and the flexible ligand 1,4-bis­(1,2,4-triazol-1-ylmeth­yl)benzene adopts a bis-monodentate bridging mode linking the CuII atoms. It is further assembled by O—H⋯O hydrogen-bond inter­actions involving both the coordinated and uncoordinated water molecules. The latter exhibits half-occupancy

Added value of the regionally coupled model ROM in the East Asian summer monsoon modeling

The performance of the regional atmosphere-ocean coupled model ROM (REMO-OASIS-MPIOM) is compared with its atmospheric component REMO in simulating the East Asian summer monsoon (EASM) during the time period 1980–2012 with the following results being obtained. (1) The REMO model in the standalone configuration with the prescribed sea surface conditions produces stronger low-level westerlies associated with the South Asian summer monsoon, an eastward shift of the western Pacific subtropical high (WPSH) and a wetter lower troposphere, which jointly lead to moisture pathways characterized by stronger westerlies with convergence eastward to the western North Pacific (WNP). As a consequence, the simulated precipitation in REMO is stronger over the ocean and weaker over the East Asian continent than in the observational datasets. (2) Compared with the REMO results, lower sea surface temperatures (SSTs) feature the ROM simulation with enhanced air-sea exchanges from the intensified low-level winds over the subtropical WNP, generating an anomalous low-level anticyclone and hence improving simulations of the low-level westerlies and WPSH. With lower SSTs, ROM produces less evaporation over the ocean, inducing a drier lower troposphere. As a result, the precipitation simulated by ROM is improved over the East Asian continent but with dry biases over the WNP. (3) Both models perform fairly well for the upper level circulation. In general, compared with the standalone REMO model, ROM improves simulations of the circulation associated with the moisture transport in the lower- to mid-troposphere and reproduces the observed EASM characteristics, demonstrating the advantages of the regionally coupled model ROM in regions where air-sea interactions are highly relevant for the East Asian climate

Efficacy of 23G intra-infusion-assisted scleral buckling on spherical retinal detachment

AIM: To observe the treatment effect and discuss availability of spherical retinal detachment by 23G intra-infusion-assisted scleral buckling. METHODS: Twenty-one eyes were randomly selected from in-patients with rhegmatogenous retinal detachment with much subretinal fluid and spherical appearance between February 2017 and February 2018, which were suitable for scleral buckling. The 23G intra-infusion was placed in the pars plana of ciliary body before the surgery. Retinal hole was not solidified during operation. Laser photocoagulation was performed around the retinal hole after surgery. Retinal reattachment state and the complications were evaluated by 3 to 10mo follow up. RESULTS: All patients have undergone operations smoothly. Subretinal fluid was drainage, chroidal bleeding and retinal incarceration did not appear during the operation. Eighteen eyes achieved retinal reattachment on the first postoperative day; Subretinal fluid of two eyes was asorbed fully; One eyes achieved retinal reattachment after the adjustment by the external pressure block. One eyes with recurrence achieved retinal reattachment after vitreoretinal surgery. One eye developed complication with subretinal hemorrhage and the range of bleeding was less than 1PD, which was absorbed after 3mo. There were no eyes found abnormal intraocular pressure, anterior segment ischemia or other sever complications.CONCLUSION: The 23G intra-infusion was pre-placed before relieving fluid in the scleral buckling of retinal detachment, which can effective keep intraocular pressure stably and reduce the possibilities of explosive suprachoroidal hemorrhage and postoperative choroidal amotio triggered by fast decrease of intraocular pressure. The retina is flat basically and the hole location is relatively accurate, which improve the success of the surgery

The versatile application of cervicofacial and cervicothoracic rotation flaps in head and neck surgery

<p>Abstract</p> <p>Background</p> <p>The large defects resulting from head and neck tumour surgeries present a reconstructive challenge to surgeons. Although numerous methods can be used, they all have their own limitations. In this paper, we present our experience with cervicofacial and cervicothoracic rotation flaps to help expand the awareness and application of this useful system of flaps.</p> <p>Methods</p> <p>Twenty-one consecutive patients who underwent repair of a variety of defects of the head and neck with cervicofacial or cervicothoracic flaps in our hospital from 2006 to 2009 were retrospectively analysed. Statistics pertaining to the patients' clinical factors were gathered.</p> <p>Results</p> <p>Cheek neoplasms are the most common indication for cervicofacial and cervicothoracic rotation flaps, followed by parotid tumours. Among the 12 patients with medical comorbidities, the most common was hypertension. Defects ranging from 1.5 cm × 1.5 cm to 7 cm × 6 cm were reconstructed by cervicofacial flap, and defects from 3 cm × 2 cm to 16 cm × 7 cm were reconstructed by cervicothoracic flap. The two flaps also exhibited versatility in these reconstructions. When combined with the pectoralis major myocutaneous flap, the cervicothoracic flap could repair through-and-through cheek defects, and in combination with a temporalis myofacial flap, the cervicofacial flap was able to cover orbital defects. Additionally, 95% patients were satisfied with their resulting contour results.</p> <p>Conclusions</p> <p>Cervicofacial and cervicothoracic flaps provide a technically simple, reliable, safe, efficient and cosmetic means to reconstruct defects of the head and neck.</p