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Aims: Diabetic peripheral neuropathy (DPN) often coexists with sudomotor dysfunction, resulting in an increased risk of diabetic foot. This study aimed to explore an efficient method for early diagnosis of DPN by establishing a quantitative Neuropad. Methods: We recruited 518 patients with type 2 diabetes. Neuropathy Symptoms Score (NSS) combined with Neuropathy Disability Score (NDS) was used to assess distal symmetrical peripheral neuropathy (DSPN). The area under the ROC curve (AUROC), sensitivity, and specificity were used to compare the diagnostic efficacy of quantitative Neuropad (the change rate of the chromatic aberration value per minute) and two types of visual Neuropad (visual Neuropad A: whether the time to complete colour change within 10 min, visual Neuropad B: the time to complete colour change) for DPN. Results: We did not observe very good diagnostic efficacy of Neuropad (visual Neuropad A and B: 0.59 and 0.64, quantitative Neuropad AUROC: 0.62–0.64) when using standard DSPN diagnostic criteria (NDS 6–12 or NDS 3–5 combined with NSS 5–9). When DPN was assessed by NSS + NDS ≥ 4, visual Neuropad B improved the specificity (AUROC 0.72, 67.00%, specificity 71.70%) by extending the detection time compared with visual Neuropad A (AUROC 0.62, sensitivity 81.80%, specificity 41.70%). Quantitative Neuropad significantly improved the diagnostic effect (AUROC 0.81, sensitivity 80.0%, specificity 76.3%) and reduced the detection time (4 min). Conclusions: This study provides a new quantitative Neuropad, which has great potential to be an extremely useful diagnostic tool for early screening of sudomotor dysfunction in the clinical practice. [ABSTRACT FROM AUTHOR]

An adaptive reaching law of chattering‐free discrete‐time sliding mode control is proposed for the systems with external disturbance. An adaptive function is proposed in the reaching law which can increase reaching speed as sliding variable is far away from zero and avoid undesired chattering when sliding variable is close to origin. Moreover, a third‐order backward difference of disturbance is added to obtain a narrower quasi‐sliding mode band (QSMB). Both the closed‐loop system performance and finite reaching steps to achieve the desired QSMB are theoretically analyzed. The simulation results verify the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

Three-dimensional Reynolds-averaged Navier-Stokes (RANS) solutions from CFX were utilized to investigate the leakage flow characteristics in the labyrinth honeycomb seal of steam turbines. At first, the accuracy and reliability of the utilized RANS approach was demonstrated using the published experimental data of the honeycomb seal. It showed that the utilized numerical method has sufficient precision to predict the leakage performance in seals. Then a range of sealing clearances, cell diameters, cell depths, rotation speeds, and pressure ratios were investigated to determine how these factors affect the leakage flow rate of the labyrinth honeycomb seal. The computed leakage flow rate increased with increasing sealing clearance and pressure ratios. Furthermore, the results show that the studied labyrinth honeycomb seal has the optimum sealing performance in the case of honeycomb cell diameter equals labyrinth step width, and the ratio of the honeycomb cell depth to honeycomb cell diameter is 0.93 under the designed condition. The flow pattern of each case is also illustrated to describe the leakage flow characteristics in labyrinth honeycomb seals. [DOI: 10.1115/1.4000091] Keywords: labyrinth honeycomb seal, leakage flow, numerical simulation

This paper proposes a novel nonsingular terminal sliding mode control combined with global sliding surface for a class of uncertain nonlinear second-order systems. The suggested control approach is developed based on the Lyapunov theory. The sliding mode reaching the sliding surface in finite time can be guaranteed. Furthermore, chattering phenomenon caused by the switching control action can be eliminated theoretically, and desirable control performance is realized. The simulation and tank test results for heave control of a remotely operated vehicle are presented to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]