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Vehicle wheel traction forces play an important role in vehicle performance, especially for four-wheel-drive vehicles, where a transfer case clutch is used to distribute torque between front and rear wheels. Due to lack of production ready low-cost torque sensor, the transfer case clutch torque is not measured and needs to be estimated accurately to optimize vehicle traction performance. This article proposes to estimate the transfer case clutch torque by forming an estimation problem with unknown system input(s). Specifically, a unified clutch torque estimation model is developed for different clutch conditions, where overtaken-clutch case is treated as a special case of slip-clutch condition with slip-speed equals to zero. Note that under overtaken condition, the associated system model with only one known input is different from that under slip condition with two known inputs. A real-time implementable recursive solution for unknown input(s) is obtained by utilizing an unknown input observer based on the extended Kalman filter (EKF-UIO) algorithm. Comparing with the existing direct estimation method and experimental measured data, it is found that the proposed EKF-UIO algorithm is able to reduce both absolute mean square error and relative-mean-square error significantly with respect to the measured clutch torque under both slip and overtaken conditions. In summary, the EKF-UIO estimation algorithm based on the unified clutch torque model is able to estimate clutch torque accurately.

Purpose Common peroneal nerve (CPN) palsy is quite disabling and every effort should be made to prevent its injury during the treatment. Methods We retrospectively reviewed the prospectively collected data of 7 cases of tibial plateau fractures in association with proximal fibula fracture from January 2019 to September 2019 who presented to emergency room of our hospital. Results In addition to fibular neck fracture, the first case had type 6 tibial plateau displaced fracture and the second case had displaced acetabular fracture with instability of knee with tibial tuberosity avulsion. CPN palsy developed following application of distal tibial skeletal traction in both the cases. Other 6 such cases remained neurologically intact as traction was not applied to them. Conclusion Such iatrogenic complication could have been prevented if the injury pattern of "concomitant medial and lateral columns" of the proximal leg is kept in mind by the treating surgeon before applying skeletal traction.

In high power traction drives using induction motors, during operation above the base speed, it is generally preferred to drive the machine in the square-wave mode since it offers maximum DC-bus utilization and reduced switching loss. However, the conventional field oriented control method cannot control the drive effectively in square-wave mode since independent control of torque and flux is difficult to achieve due to stator voltage saturation. This paper proposes a new technique to control the drive in the square-wave mode where only one degree of freedom is available for control. In the square-wave mode, the proposed method controls the torque of the machine by directly varying the stator voltage angle with respect to the rotor flux axis. The flux of the machine is kept at a required value below the saturation limit by appropriate selection of the operating point. The proposed control strategy also offers good torque dynamics in the square wave operating mode. The control algorithm is experimentally verified on a 5.5 kW induction machine drive and the experimental results are presented.

The high current pulse in traction network is an extreme and dangerous situation, and the short-circuit experiment is to simulate this situation. The short-circuit experiment of traction network has always been very important to detect the safety and stability of high-speed railway (HSR). This paper presents an electromagnetic emission (EME) prediction method of traction network short-circuit experiment. The multi-conductor transmission line (MTL) is used to model the traction network, considering the non-uniform distribution of each conductor, the tunnel, and other complex factors. General regression neural network (GRNN) is introduced to simplify the calculation of parameter matrix in the tunnel. Combined with the finite difference time domain (FDTD) method, the low frequency transient current distribution and EME on the line are predicted, and its accuracy is verified by field test. This method provides a theoretical basis for the evaluation of electromagnetic interference (EMI) of HSR and the protection of surrounding weak current equipment.

Co-phase traction power supply system provides the insights for solving the existing power quality and electrical sectioning issues in high-speed railways, and the flexible control of co-phase traction substation (CTSS) with the integration of photovoltaic (PV) and hybrid energy storage system (HESS) attracts widespread attention. However, the strong volatilities and uncertainties of PV and traction load introduce challenges to the reliable and economic operation of CTSS. In this study, the energy management of CTSS aims at minimizing the operating cost of CTSS by coordinating PV, HESS, power flow controller (PFC) and the energy transactions with the power grid, where the three-phase voltage unbalance constraint is taken into account in particular. Furthermore, to handle the uncertainties of PV and traction load, a two-stage robust optimization model is proposed. The first stage determines the operating status of HESS and energy transaction status with grid, and the second stage aims at finding the optimal scheduling power of CTSS and the worst-case scenario with maximized operating cost of CTSS. A column-and-constraint generation algorithm is employed to solve this robust optimization model, along with efficient linearization approaches for the formulation of mixed-integer linear programming. The proposed methodology is tested with a real high-speed railway line case in China.

The need to increase the power density of traction inverters for the electrified transportation systems offers an opportunity to adopt silicon carbide (SiC) devices. To ensure the system reliability, it is critical to select a SiC power module that can dissipate a sufficient amount of power to avoid operating beyond the maximum allowed junction temperature. In this work, a comprehensive electro-thermal characterization procedure based on the virtual junction temperature concept is proposed to characterize the module’s maximum power dissipation as a function of coolant temperature. Using the characterization results, it is feasible to determine the module’s safe operating area for a traction application in terms of the switching frequency and the coolant temperature. The proposed characterization method is demonstrated on a custom 1200-V SiC module to validate its feasibility for an 800-V, 150-kVA traction inverter system. In addition, the design approach for a low-inductance bussing structure using heavy copper printed circuit board (PCB) is presented in this work, which leads to a snubberless, compact and low-cost system design. Measurements and experimental studies have been performed to validate the effectiveness of PCB bussing design. The overall volume of the inverter system is around 1.75 L, which leads to a volumetric power density of 86 kVA/L.

The control system for energy-efficient train operation with the inclusion of a detailed train motion model and train traction system energy efficiency is presented in the paper. A piecewise affine train model is constructed with the parameters obtained for the electromotive train of an industrial manufacturer. The model encompasses intrinsic features of the train system such as linearized resistance force, a set of traction and braking force physical limitations and passengers comfort constraints. The resulting quadratic optimization problem is solved parametrically through dynamic programming giving the off-line precomputed optimal control law that is a function of train speed and traversed path. The on-line computed traction force profile is then tuned with respect to the traction system energy efficiency. The developed control system is evaluated on a detailed real case study scenario put together with a railway operator and the train manufacturer. The presented results show the possibility of significant energy consumption reductions achieved by energy-efficient train control.

A bidirectional discontinuous-conduction mode constant on-time variable-frequency control strategy for a three-phase interleaved dc-dc converter suitable for traction applications is proposed in this work. The strategy enhances the converter efficiency at low-power conditions, providing fairly constant efficiency over the entire power range, by synchronously controlling both the bottom and top switches of the three boost phases. Simulation and experimental results demonstrate the validity and effectiveness of the proposed approach on a 10-kW bidirectional interleaved boost converter.

Novel cable traction power supply system (NCTPSS) is a kind of long distance co-phase traction power supply system (TPSS), it can effectively solve problems caused by train's passing through electrical phase separation and improve utilization rate of regenerative energy in system, which is an ideal traction power supply mode. However, its structure is relatively complex due to cable power supply pattern, and internal power flow distribution mechanism still needs further study. In order to establish train-network coupling power flow calculation model, in this paper, two-port network model of each system component is established at first, then equivalent solid circuit model of the system is built by external cascade strategy and tearing nodal method. Then, power flow, the change of traction transformer power output and network voltage are analyzed under the condition that trains work in traction and regenerative braking condition, based on actual train operation schedule. The research shows that the proposed model can accurately calculate and detailed reflect electrical characteristics of NCTPSS, traction transformer capacity is effectively decreased compared with that needed in existing TPSS; Regenerative power can feed back to entire cable traction network and be reused by traction trains with high utilization rate inside NCTPSS.

The thermal stress imbalance is a challenge for the reliability and in-service lifetime of modular multilevel converters, especially in traction drive applications. The finite control set model predictive control (FCS-MPC) can offer an effective solution to this issue, but it is faced with two difficulties, that is the weight allocation of electrical and thermal variables with different natures in control objectives functions, and dynamic weighting factor adjustment during the switching of variable operations. Therefore, an electro-thermal performance-based FCS-MPC (ETP-FCS-MPC) for dynamic thermal balance control is proposed, which can not only achieve thermal stress balance in converters with more intuitive and time saving ways, but also offer dynamic compromise schemes between the electrical and thermal performance of converters in the speed switching process. First of all, dynamic electrical and thermal models of converters are presented. Then, the absolute error-based electrical control objective and the energy loss variance-based thermal control objective are designed. Moreover, a performance-based normalized control objective function and an outer loop control feedback-based dynamic weighting factor are proposed. Finally, HIL-based test is carried out to verify the effectiveness of the proposed method, the test results show the merits of the proposed method.

In this paper, a predictive energy management system (EMS) for dual-motor battery electric vehicles (BEVs) is proposed, considering temperature-dependent traction inverter loss. First of all, we establish a high-fidelity BEV powertrain under a hardware-in-the-loop (HIL) testbed. The high-frequency switching of power electronics and electro-thermal traction inverters is considered. Subsequently, because transient current and voltage-based electro-thermal models in the literature are unsuitable for vehicle-level EMS design, we propose an innovative control-oriented inverter loss model and introduce approximate junction temperature dynamics in the predictive EMS. Then, based on Pontryagin’s Minimum Principle, we propose a fast solution algorithm, making it possible to validate the EMS in a real-time HIL testbed. To the best of our knowledge, temperature-dependent traction inverter loss has not yet been studied in EMSs. The traction inverter loss model has been experimentally validated and used in the proposed predictive EMS to provide more comprehensive validation. Results have shown that the proposed predictive EMS can reduce the power loss by 5-9% compared to the widely-used instantaneous optimization-based controller in academia.

A type of 3.3-kV/450-A half-bridge insulated-gate bipolar transistor power module combining the silicon (Si) and silicon carbide (SiC) technologies has been developed and reported in this article, for the miniaturization of the Chinese high-speed railway rolling stock traction inverters. This module is developed by integrating the next-generation industrial standard high-voltage packaging topology and the state-of-the-art 3.3 kV wide bandgap semiconductor chip technology, to reduce the waste power dissipation during operation, which in turn can lead to effective downsizing of key components in the traction inverter design. The module layout characteristics and the SiC Schottky barrier diodes design for substitution of the conventional Si fast recovery diodes will be described in detail. The mechanical, thermal, and electrical performances of the hybrid module are compared comprehensively with the Si-based counterpart. Based on the experimental results, an inverter system level evaluation of both modules is also conducted by electro-thermal simulation. The hybrid module shows advantages in loss reduction leading to great potential of system miniaturization, which is a cost effective solution for massive upgrading of the existing high-speed train traction inverters.

Проведено лікування 73 хворих із 77 осколковими переломами діафіза кінцівок В і С типів. Додатково розглянуті такі ознаки перелому, як величина зміщення уламків за шириною і протяжність зони осколкового руйнування сегмента. Для фіксації відламків використовували стрижневі апарати (70), виготовлені ПП «ОртоПАК», або шинно-матерчаті ортези (7) (при переломах плеча). При 39 переломах вправлення уламків проведено на системі витягнення, після чого вони фіксовані апаратом, у 24 закрито одномоментно і у 15 — відкрито. Основним вважали відновлення правильних осьових взаємозв’язків уламків, і при цьому часто залишалися залишкові зміщення по ширині на 1/2–2/3 діаметра. Через кілька днів хворі починали дозоване навантаження пошкодженої кінцівки. Середні терміни фіксації апаратом або ортезом становили для стегна — 105 днів, гомілки — 135, плеча — 88. Частота незрощень після первинно розпочатого лікування мала місце у 5 хворих (6,5 %). При виявленні у них патологічної рухливості уламків на рівні одного зі зламів через 3–4 місяці лікування доповнювали кістковою автопластикою з продовженням фіксації тим самим апаратом і збереженням навантаження кінцівки.

An analysis of the data from 40 patients with instability and herniated disc in the lumbar spine has been carried out. The short-term (1 month) and long-term (1.5 years) results of conservative treatment were analyzed, and also the nature and characteristics of their course in the early and late periods were examined. Combined use of manual therapy and traction is not allowed as a method of conservative treatment for disc herniation associated with instability. Rehabilitation of the patient (targeted recovery of reliability of the spine functioning under physiological, common and industrial loads) is advisable.

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The paper presents a wall-climbing robot featuring self-compliance for variable curvature facades. The high payload and maneuverability make it highly potential in heavy-duty operation of industrial applications. The robot consists of two traction modules and one link module. Each traction module is equipped with magnetic adhesion and crawler traction submodules. The two traction modules are connected by the link module with 4 degrees of freedom (DoF) of passive compliance. Variable curvature facade self-compliance is achieved by the passive compliant link module, which results in the attitude change decoupling of the two traction modules. The attitude can be adjusted under the effect of magnetic adhesion force to comply with the curvature variations. High payloads are achieved by the large contact area between the crawler and the surface. Omni-directional high maneuverability is enabled by the speed difference between the motors of two traction modules. The robot can maneuver in any direction on the surface with a minimum radius of 1 m and carry 36 kg payload on vertical surfaces.

Objective Modified surgical lip repositioning (MLR) is a conservative method for correcting gummy smile (GS). However, its long-term evaluation in the prevention of relapse following lip repositioning surgeries remains questionable. This long-term study was therefore conducted to assess MLR with and without an adjunctive internal dual muscle traction approach (iMTA) in the treatment of GS. Methods This study was performed on 20 cases with GS. They were randomly and equally distributed to be treated either by MLR alone (Control) or augmented with iMTA (Test). Participants were assessed for GS reduction at 3, 6 and 12 months postoperatively. The patient's satisfaction scores were assessed at 12 months in both groups. Results The control participants revealed in a remarkable decrease in gingival exposure (2.7 mm ± 0.48) (P-value ≤ 0.05), while the test ones demonstrated a more significant reduction in GS (1.6 mm ± 0.52) (P-value ≤ 0.05). Satisfaction scores were significantly reported in the test group (9.3 ± 0.78 when compared to the control group (7.8 ± 1.3), (P-value ≤ 0.05). Conclusions Within the limits of this study, our long-term results revealed that MLR is an effective method for treating GS, while iMTA offered more stable results at 12 months when used as an adjunct to MLR.

For the single-phase high-power railway traction system, the inevitable second-order resonating power has become a critical issue to the traction system. In this article, a power-decoupling solution is proposed to replace the conventional passive LC resonance filter by utilizing the buck-type bidirectional dc/dc converter (BBDC) of hybrid electric multiple units, which is designed to power the train in nonelectrified routes using the on-board battery. By considering both the current ripples in the battery mode and the power decoupling in the catenary mode, the corresponding parameter design process of the BBDC is presented. Based on the power coupling phenomenon and the spectrum characteristic of the BBDC, a direct resonance control method is proposed to decouple the low-order resonating power. Simulations and experiments are carried out to validate the effectiveness of the new proposal. The results demonstrate that the proposal is almost the same as using the conventional passive LC resonance filter for power decoupling in both steady and dynamic operation scenarios.

Maxillary, mandibular, and dental effects resulting from the use of a removable intraoral Class III traction appliance as well as the protraction facemask in treatment of Class III malocclusion were assessed. This is a retrospective study comparing measurements from pre-treatment and post-treatment lateral cephalometric radiographs of two groups. Group 1 consisted of 25 patients treated with rapid palatal expansion followed by a removable intraoral Class III traction appliance. Group 2 consisted of 25 patients treated with rapid palatal expansion followed by a protraction facemask. The subjects were Caucasian, both male and female, with an age range of 3 to 12 years. The only significant differences were in length of treatment time and the skeletal change of angle SNA. The mean treatment times were 6.96 months and 10.96 months in the removable Class III traction appliance and protraction facemask groups, respectively. The mean increase in SNA was 0.46 degrees in the removable Class III traction appliance group and 1.81 degrees in the protraction facemask group. A removable Class III traction appliance provides orthodontists with another useful Class III treatment modality.

Induction motor is widely used in many fields due to its simple structure, well-grounded operation, and small capacity of precise power. The conventional traction motor drives have been observed experimentally that there is a presence of speed deviation and torque ripples. Therefore, it becomes much essential to verify the control performance of the system by including its non- linear characteristics. To overcome the disadvantages mentioned above, the parameters of an induction motor which is most efficient will be estimated. The induction motor is dynamically modelled using this estimated parameter. So the proposed system focuses on improving the performance of traction motor drive by implementing the multilevel inverter fed sensor less induction motor using modified model reference adaptive system and compared with conventional model reference system based voltage source inverter. The simulation and hardware results will be realized for proposed system and compared with conventional system.

Introduction: Recent studies have shown that the likelihood of semitendinosus-gracilis graft rupture is inversely correlated to its diameter. A graft can be prepared in a five-strand or four-strand fashion to increase its diameter. However, the biomechanical superiority of five-strand semitendinosus-gracilis grafts is still under debate. Objective: This study aimed to evaluate the biomechanical characteristics of matched four-strand and five-strand human semitendinosus-gracilis grafts. Methods: We evaluated semitendinosus-gracilis tendons harvested from ten fresh human male and female cadavers, aged 18-60 years. Four-strand or five-strand grafts were prepared with the tendons and fixed to wooden tunnels with interference screws. Each graft was submitted to axial traction at 20 mm/min until rupture; the tests were donor matched. Data were recorded in real time and included the analysis of the area, diameter, force, maximum deformation and stiffness of the grafts. Results: The diameter, area and tunnel size were significantly greater in the five-strand grafts than in the four-strand grafts. There were no significant differences in biomechanical properties. The area and diameter of the graft were positively correlated to stiffness, and inversely correlated to elasticity. There was no significant correlation between graft size and maximum force at failure, maximum deformation or maximum tension. Conclusion: Five-strand hamstring grafts have greater area, diameter and tunnel size than four-strand grafts. There were no significant differences in biomechanical properties. In this model using interference screw fixation, the increases in area and diameter were correlated with an increase in stiffness and a decrease in elasticity. Level of evidence V; biomechanical study. RESUMEN Introducción: Estudios recientes demostraron que la probabilidad de ruptura de los injertos semitendinoso y gracilis (STG) durante el pos operatorio de reconstrucción de ligamento cruzado anterior (LCA) está inversamente correlacionada a su diámetro. Un injerto puede ser preparado para obtener cuatro o cinco hebras para aumentar su diámetro, pero la superioridad biomecanica de los injertos STG de cinco hebras aún se mantiene en discusión. Objetivo: Evaluar las características biomecánicas de los injertos STG de humanos de cuatro o cinco hebras por pares. Métodos: Fueron evaluados tendones STG de diez cadaveres masculinos y diez cadaveres femeninos frescos, entre los 18 y 60 años. Los injertos de cuatro y cinco hebras fueron fijados en túneles de madera con tornillos de interferencia. Cada injerto fue sometido a una tracción axial de 200mm/min hasta su ruptura; estos tendones fueron separados por pares de acuerdo con sus donadores. Los datos fueron registrados en tiempo real y incluyeron el análisis del área del injerto, diámetro, fuerza, deformación máxima y rigidez. Resultados: Los resultados sobre el diámetro, el área y el tamaño del túnel fueron significativamente mayores en los injertos de cinco hebras que en los de cuatro. No existieron diferencias significativas en las propiedades biomecánicas. El área y el diámetro del injerto fueron correlacionados positivamente con la rigidez e inversamente con la elasticidad. No existió correlación significativa entre el tamaño del injerto y la fuerza máxima al momento de la falla, Máxima deformación o máxima tensión. Conclusión: Los injertos de isquiotibiales de cinco hebras tienen una área, diámetro y tamaño de túnel más grande que los injertos de cuatro hebras. No hubieron diferencias biomecánicas significativas. Los aumentos de área y diámetro en este modelo con la fijación de tornillo de interferencia fueron correlacionados con aumento de en la rigidez y una disminución en la elasticidad. Nivel de evidencia V; estudio biomecánico. RESUMO Introdução: Estudos recentes demonstraram que a probabilidade de ruptura do enxerto dos tendões do semitendíneo e do grácil (STG) é correlacionada inversamente com seu diâmetro. Um enxerto pode ser preparado de forma quádrupla ou quíntupla para se aumentar o diâmetro. No entanto, a superioridade biomecânica dos enxertos STG quíntuplos ainda está em debate. Objetivo: Este estudo teve como objetivo avaliar as características biomecânicas dos enxertos STG humanos quádruplos ou quíntuplos pareados. Métodos: Foram avaliados tendões STG retirados de dez cadáveres masculinos e femininos frescos, com idades entre 18 e 60 anos. Os enxertos quádruplos ou quíntuplos foram preparados com os tendões e fixados em túneis de madeira com parafusos de interferência. Cada enxerto foi submetido à tração axial a 20 mm/min. até a ruptura; os testes foram pareados de acordo com os doadores. Os dados foram registrados em tempo real e incluíram a análise de área, diâmetro, força, deformação máxima e rigidez dos enxertos. Resultados: O diâmetro, a área e o tamanho do túnel foram significativamente maiores nos enxertos quíntuplos do que nos enxertos quádruplos. Não houve diferenças significativas nas propriedades biomecânicas. A área e o diâmetro do enxerto foram correlacionados positivamente com a rigidez e inversamente com a elasticidade. Não houve correlação significativa entre o tamanho do enxerto e a força máxima na falha, deformação máxima ou tensão máxima. Conclusão: Os enxertos quíntuplos dos músculos isquiotibiais têm maior área, diâmetro e tamanho do túnel do que os enxertos quádruplos. Não houve diferenças significativas nas propriedades biomecânicas. Neste modelo de fixação com parafuso de interferência, aumentos da área e do diâmetro foram correlacionados com o aumento da rigidez e a diminuição na elasticidade. Nível de evidência V; Estudo Biomecânico.

In this work, a current sensors fault tolerant control system (FTCS) for induction motor traction drives is proposed. The FTCS uses a single observer for the detection and isolation of disconnection and gain faults occurred in a single or two current sensors available in the drive. Moreover, the observer signals are used for the control reconfiguration within a field-oriented control strategy. The effectiveness of the FTCS (detection, isolation and reconfiguration) and the performance of the control strategy after different faults and perturbations is verified by simulation results using an electric vehicle model.

This paper presents the developments of sensorless control of an interior permanent-magnet synchronous motor (IPMSM) based on signal injection for the last five years. At first, modeling of an IPMSM is discussed. In contrast to the conventional inductance based voltage model, the flux model considering saturation and spatial harmonics of IPMSM is introduced. For the identification of the flux model, either finite element analysis or experimental test is required. Secondly, based on the flux model, some sensorless control methods of IPMSM for the traction of a vehicle, where IPMSMs are heavily saturated for higher torque density, are described. In contrast to the belief that there should be a certain saliency for the sensorless control based on the signal injection, it is explained that sensorless control is possible even in a reversed saliency region. Thirdly, the methods to decrease the magnitude of the injected signal itself are discussed together with the optimization of the frequency of the signal. The simulation and test results for typical automotive-grade IPMSMs with several sensorless methods exploiting square-wave signal injection are presented, and the physical meaning of the test results are discussed. Finally, future outlook based on recent developments is addressed.

Currently, chemical methods of weed control are increasingly being replaced by mechanical weeding. One of the promising mechanical devices for weed control is a rotary loosening and separating stratifier. This tillage machine can provide high quality tillage to a depth of up to 18 cm. Its performance is determined by the width of the grip of the gun and the speed of movement and is limited by the traction capabilities of the tractor. Using the Goryachkin formula for the traction resistance of a tillage machine, the authors obtained the dependence of productivity on the width of the grip and the speed of movement at different depths of tillage. The obtained dependencies on the example of tractors John Deere 8330, HTZ 16131-05 and MTZ 1523.3 showed the presence of a pronounced maximum, which led to the solution of the optimization problem. The article presents a method for calculating the optimal width of the grip and the speed of movement that ensure the maximum productivity of the tillage machine, depending on the depth of processing and the specific resistance of the soil. The use of optimal parameters of the tillage machine allows you to increase its productivity by 2–3 times.

The urban rail transit system has the characteristics of wide voltage fluctuation, intermittent and strong impact load, limited heat dissipation capacity. The high-speed flywheel energy storage system (FESS) is used to provide network voltage stability and regenerative braking energy recovery due to its high power density, unlimited number of charge-discharge cycles, fast response and environmental friendliness. When considering the design of high-speed FESS converter with 3.6 kHz fundamental frequency and 330 kW rated power used in 1500 VDC urban rail transit system, the two-stage topological converter reduces the efficiency and increase the cost and size, meanwhile, the series-connected converters and the multilevel converter increase the difficulties of control and insulation, so the two-level and I-type three-level converters of high-speed FESS are designed and evaluated. Several comparisons are made by detailed experimental data from the perspective of the traction load characteristics of the 1500 VDC urban rail transit system and the technical and economical requirements of the high-speed FESS. It is found that the three-level converter has significant advantages in matching the traction load characteristics for its higher duty cycle capability, as well as improving the technical and economical performances such as efficiency, du/dt value, THD, voltage stability, and reducing the cost by 40% when compared to the two-level converter. While in the future MW class high-speed FESS development, the maximum output power capacity of the three-level FESS is relatively lower than that of the two-level FESS. The theoretical analyses were verified by experiments.

Introduction: Before corrective surgery for idiopathic scoliosis, the stress x-rays are indispensable to collect information regarding the reducibility of deformity, deciding fusion levels, and categorizing curve types and so on. The hanging radiograph has not been conducted preoperatively so far as known. The objective of this study was to investigate retrospectively the significance of the hanging radiograph for prediction of the curve correction with surgical procedure by comparing with the side-bending and the traction radiographs. Methods: The subjects enrolled in current study were 22 cases of idiopathic scoliosis who performed posterior instrumentation and fusion by ISOLA method between 2008 and 2014. They included 2 males and 20 females, with a mean age of 16 years and 8 months. The type of curves by Lenke classification were type 1 in 20 cases, type 2 in 1 case, and type 3 in 1 case. We investigated the correction rates of main thoracic curves in side-bending, traction, and hanging positions and compared them with that after surgery. In addition, correction indices were also calculated and compared among these stress x-rays. Results: The correction rate after surgery was 65.9% that was statistically higher than those in side-bending (44.2%), traction (46.6%), and hanging (22.1%) positions. There were statistical correlations between the correction rates after surgery and in side-bending position (R=0.73) and those after surgery and in traction position (R=0.57). However, there was no statistical correlation between the correction rates after surgery and in hanging position (R=-0.01). With regard to the correction indices, that in hanging position (3.67) was statistically higher than those in side-bending (1.51) and traction (1.45) positions. Conclusion: The correction rates in side-bending and traction positions seem to be useful to estimate the amount of curve correction before surgery whereas, that in hanging position did not have any significance as preoperative evaluation.

Oil-impregnated paper (OIP) bushing is essential equipment in traction power supply systems, and its moisture status is directly related to the power transmission of high-speed railway. Also, the moisture distribution in the OIP bushing insulation is usually nonuniform. The frequency-domain dielectric spectroscopy (FDS) method is now widely accepted as the most potential method for evaluating the moisture status of the OIP traction bushing with nonuniform moisture distribution. However, as far as the FDS curve reconstruction of field bushing is concerned, it remains a challenge. In this article, based on the extended Debye model, a new curve reconstruction method (including equivalent circuit and mathematical models) of the bushing dielectric response is proposed. Then, the reconstruction method is converted into a mathematical problem of programming optimization. Based on the advantages of metaheuristic algorithms such as simplicity, flexibility, derivative-free mechanism, and local optimal avoidance, an improved metaheuristic algorithm was used to address the optimization problem. Finally, the proposed method was tested on bushing samples and real bushings. The research shows that the proposed method of curve reconstruction can well characterize the FDS curves of the traction bushing insulation with the nonuniform moisture distribution.

Autotransformer (AT) traction network (ATN) expands widely with the rapid development of high-speed railway (HSR). The fault occurrence in ATN will affect the safety and reliability of power supply for electric multiple units (EMUs). However, due to the nonlinear relationship between measured impedance and distance, the accuracy and efficiency of the fault location for ATN is facing serious challenges, especially with the diverse fault types and operation modes. In this paper, the general circuit topology of subsections is given and the characteristics of voltage distribution is analyzed according to the impedance matrix of ATN. Through the decoupling method, a comprehensive equivalent model adopting composite impedance is established, which can illustrate a series of characteristics for all fault types. Furthermore, the fault-location method is proposed to express the mapping between the fault position and the relevant electrical quantities for the subsection, and then a reasonable compensation for the effect of mutual impedance between faulty and non-faulty subsections is provided to improve the accuracy. Consequently, the multi-terminals synchronous information is employed for unified fault-location for ATN. Case studies including simulation and field testing have verified that the method is accurate and quite robust to various fault scenarios.

With the gradual acceleration of modernization, metro projects have been opened for the development and construction of urban areas. How to ensure the smooth operation of subway project in public service has become the focus of urban public safety service research. In view of this content, this paper studies the subway field of urban rail transit operation and improves the public safety of urban rail transit operation. Firstly, the factors affecting the track traction power supply are analyzed, the anti-interference technology of ring array electromagnetic sensor is added, and the research scheme is formulated according to the track potential research standard to ensure the operation of the power supply system. Then, the electromagnetic sensor traction algorithm is used to detect the subway track power supply signal, and the working characteristics and advantages of single electromagnetic induction and double electromagnetic induction are analyzed. The experimental results show that compared with the traditional electromagnetic sensor power supply signal detection algorithm, the content of this paper can judge whether the power supply is normal according to electromagnetic induction, detect whether the subway traffic deviates from the track traction coordinates, and understand the size of the deviation from the track. It improves the efficiency of traction power supply detection, stabilizes the running track of subway traffic, and is conducive to the protection and development of urban public safety.

BACKGROUND Radiographic assessment of esophageal growth in long-gap esophageal atresia while on traction and associated traction-related complications have not been described. OBJECTIVE To demonstrate how chest radiography can estimate esophageal position while on traction and to evaluate radiography's utility in diagnosing certain traction system complications. MATERIALS AND METHODS In this retrospective evaluation of portable chest radiographs obtained in infants with long-gap esophageal atresia who underwent the Foker process between 2014 and 2020, we assessed distances between the opposing trailing clips (esophageal gap) and the leading and trailing clips for each esophageal segment on serial radiographs. Growth during traction was estimated using longitudinal random-effects regression analysis to account for multiple chest radiograph measurements from the same child. RESULTS Forty-three infants (25 male) had a median esophageal gap of 4.5 cm. Median traction time was 14 days. Median daily radiographic esophageal growth rate for both segments was 2.2 mm and median cumulative growth was 23.6 mm. Traction-related complications occurred in 13 (30%) children with median time of 8 days from traction initiation. Daily change >12% in leading-to trailing clip distance demonstrated 86% sensitivity and 92% specificity for indicating traction-related complications (area under the curve [AUC] 0.853). Cumulative change >30% in leading- to trailing-clip distance during traction was 85% sensitive and 85% specific for indicating traction complications (AUC 0.874). CONCLUSION Portable chest radiograph measurements can serve as a quantitative surrogate for esophageal segment position in long-gap esophageal atresia. An increase of >12% between two sequential chest radiographs or >30% increase over the traction period in leading- to trailing-clip distance is highly associated with traction system complications.

Recently, the hypothesis that purely evaluative disputes are metalinguistic negotiations has gained traction. I resist a strong version of that hypothesis, and argue that some of those disputes are...

The contribution of the tire-road slip of traction wheels to the total resistance opposing the motion of a light-duty commercial vehicle has been investigated through the simulation of several homologation and custom driving cycles. The calculation of the contribution of the tire slip losses was based on the estimation of the longitudinal tire slip, by means of Pacejka’s MF5.2 tire model. In this work, the computational steps required to evaluate this contribution were implemented in a previously developed fuel consumption simulation tool. Simulations were performed under several vehicle loading conditions and tire inflation pressures on traction and non-traction wheels, and considering different tire-road adherence conditions, in order to obtain a characterization of the tire slip losses over a wide range of working conditions. An analysis of the results shows that, although the contribution of tire slip losses to the total vehicle energy demand and fuel consumption may be relevant – especially under low-load, low adherence conditions – the sensitivity of the average on-cycle vehicle energy/fuel consumption to changes in the tire inflation pressure is only affected slightly by tire slip losses. Therefore, tire slip losses can be neglected in practice, when the aim of a simulation is to optimize the tire pressure to achieve average vehicle working conditions over a driving cycle.

Robot-assisted technology has been increasingly employed in the therapy of post stroke patients to deliver high-quality treatment and alleviate therapists’ burden. This paper introduces a novel parallel end traction apparatus (PETA) to supplement equipment selection. Considering the appearance and performance of the PETA, two types of special five-bar linkage mechanisms are selected as the potential configurations of the actuation execution unit because of their compact arrangement and parallel structure. Kinematic analysis of each mechanism, i.e., position solutions and Jacobian matrix, is carried out. Subsequently, a comparative study between the two mechanisms is conducted. In the established source of nondimensional parameter synthesis, the singularity, maximum continuous workspace, and performance variation trends are analyzed. Based on the evaluation results, the final scheme with determined configuration and corresponding near-optimized non-dimensional parameters is obtained. Then, a prototype is constructed. By adding a lockable translational degree of freedom in the vertical direction, the PETA can provide 2D planar exercise and 3D spatial exercise. Finally, a control system is developed for passive exercise mode based on the derived inverse position solution, and preliminary experiments are performed to verify the applicability of the PETA.

This paper presents a practical approach designing a traction controller based on disturbance observer (DOB) in hybrid electric vehicles (HEVs). To conduct the traction control of HEVs, the proposed control scheme estimates disturbances in a specific frequency range caused by wheel-slips and reduces driving force in accordance with the estimated disturbance. A band pass filter is employed to the DOB to extract the disturbance in a specific frequency range causing wheel slip. In addition, a proportional-integral (PI) type regulator is applied to effectively reject the disturbances. To validate the proposed control algorithm, actual vehicle tests are performed using a C-segment HEV sport utility vehicle (SUV). The test results show that the proposed control algorithm achieved more enhanced energy efficiency as well as better ride comfort with maximizing traction force than the conventional control algorithm.

Footwear outsole design is an important factor for shoe-floor friction and for preventing slipping. Shoes with small, uniformly-separated tread blocks (often included on slip-resistant shoes) have ...

A variety of devices are available for the management of patients with erectile dysfunction, Peyronie's disease, penile dysmorphophobia, for support before and after penile prosthesis insertion, and after radical prostatectomy. Traction devices include, but are not limited to, Penimaster PRO (MSP Concept, Berlin, Germany), Andropenis and Andropeyronie (Andromedical, Madrid, Spain), and the Restorex (PathRight Medical, Plymouth, USA). The other type of devices are vacuum devices such the Osbon ErecAid (Timm Medical, MN, USA). Different devices are optimal for different clinical applications, and robust and contemporary clinical data show a variety of strengths and weaknesses for each device. Research currently favours the use of traction devices for improvement of penile curvature and erectile function in patients with Peyronie's disease compared with vacuum devices; Penimaster Pro and Restorex have been shown to be associated with the best outcomes in this indication. Vacuum devices are favoured for treatment of erectile dysfunction and penile length loss after radical prostatectomy; the Osbon ErecAid is the most well-studied device for this indication. Research into other uses of vacuum and traction devices, such as for penile dysmorphophobia or before and after penile prosthesis, is very limited. Compliance, cost and availability remain substantial challenges, and further high-quality evidence is required to clarify the role of traction devices in urology and sexual medicine.

This article suggests that the arbitral use of jus cogens and erga omnes is slowly producing a ‘presumption of applicability’ in investor–state arbitration tribunals tasked with determining whether international law applies to investors. Looking backward from two recent counterclaims at tribunals established under investor–state dispute settlement (ISDS) clauses in international investment agreements that support our claim, the article first analyses the evolution and use of jus cogens in attaching rights-claims to non-State subjects of international law. Secondly, it explores the origins and uses of obligations erga omnes in attaching obligations-claims to non-State subjects of international law. It attempts to define the contours of jus cogens and erga omnes as they are deployed in recent ISDS case law and highlights the limits of each concept. The article concludes that there is a potential for a presumption of applicability in international investment arbitration for investor obligations and that this presumption can be sourced from general international law.

As a component of servicing car body, the internal interfaces of aluminum alloy carbody include all connections of equipments hanged under floor and mounted on roof, which are expected to form the weak coupling relationship. For an imported prototype with primary hunting phenomenon, a dynamical design methodology of speeding-up bogies was proposed. The analysis graph of full-vehicle stability properties and variation patterns is used to clarify a self-adaptive improvement direction, i.e., λeN ≥ λemin, and λemin = (0.03–0.05). Therefore, the central hollow tread wear can be self-cleaned in time or regularly by crossing over the dedicated lines of different speed-grades. The modified strategy with strong/weak internal interface transaction of servicing car body was furthermore formulated based on the dynamical condensation method of component interface displacements. The causal relationship between bogie vibration alarm and car body fluttering phenomenon was then demonstrated by using techniques of rigid-flex coupling simulation. The self-excited vibration of traction converter intersects with the unstable hunting oscillation, ca. 9.2/9.3 Hz, which is consistent with the conclusions of tracking-test investigations on two car body fluttering formations. The technical space to promote the construction speed is thereby lost completely because of ride comfort decline, unsafe vibration of onboard electrical equipments, and weld fatigue damage of aluminum alloy car body. However, the rigid-flex coupling simulation analyses of trailer TC02/07 confirm that the safety threshold of bogie vibration warning can be appropriately increased as long as the lateral modal frequency of traction converters is greater than 12 Hz, preferably close to 14 Hz.

Background: Circumcision is the most common procedure in the neonatal period. PD was adopted for circumcision for a long time, and it underwent many modifications during the last decades. In this paper, we review retrospectively our practice in babies with isolated hooded prepuce that been circumcised with PD by using a new technique called (Traction and closure). Materials and methods: Between April 2019 and April 2021, 676 cases of circumcision were performed in the pediatric surgery clinic, 398 cases by Winkelmann clamp, and 289 done with Plastibell device. Five cases of hooded prepuce were detected on routine physical examination without hypospadias or meatal anomaly. These cases are characterized by deficient ventral preputial skin comparing to the dorsal preputial skin. All babies were in the neonatal period (less than one month of age) except for one who was 32 days old. The mean age of babies was 15.4 days. Circumcision was accomplished with PD by a new technique (Traction and closure). Results: Postoperatively no bleeding or urinary retention was noticed in all babies. Upon follow-up, all patients did not have slippage or retention of the ring where the ring fell smoothly over an expected time duration (7-11 days, mean: 9.25 days). Also, good favorable outcomes and parental satisfaction were both obtained in all cases. Conclusion: PD with technique (traction and closure) is a safe and suitable method for circumcision in babies diagnosed with an isolated hooded prepuce

The harmonic interference during the operation of rolling stock or EMU is an important interference source of signal system, especially the running track circuit. The harmonic currents in the signal band exceed the limit, which will affect the reliable operation of the track circuit. Analysis of harmonic characteristics based on traction current and the principle of harmonic suppression, a method of harmonic suppression using multiple control strategies is proposed according to the harmonic distribution characteristics of track circuit. Effectiveness of multiple control strategy for harmonic suppression of traction current is verified by simulation analysis and line operation test. The RMS of traction harmonic current can be controlled in the range of 0.3A. The overall performance of the vehicle is optimized and the electromagnetic interference of the track circuit is effectively suppressed.

In this study, the aim was to assess whether using elastic traction during the active period of distraction osteogenesis could effectively increase the vertical extension. Patients with Pruzansky-Kaban Type II mandibular deformity were recruited and randomly assigned into Elastic traction + Distraction Osteogenesis group or Distraction Osteogenesis group, respectively. During the active period, the experimental group received orthodontic elastic traction 3 days after distraction osteogenesis implantation, while the control group received no treatment. All the participants underwent computed tomography (CT) examination before surgery, at the end of the active period, 6 months and 2 years after distraction osteogenesis tractor implantation. The primary outcome was the effective vertical extension rate of the mandible from the baseline to the end of the active period after operations, and there were 7 secondary outcomes used. 70 patients were included. The effective vertical extension rates were 85.021% ± 7.432% (mean ± SD) and 68.811% ± 9.510% (mean ± SD) in the experimental and control groups, respectively (P = 0.001). The average distances between the lower middle incisor point to the sagittal plane at the end of the active period were 2.485 ± 1.411 mm and 3.938 ± 2.293 mm in the experimental and control groups, respectively (P = 0.026). At the end of the active period of distraction osteogenesis, the average values of the mandibular occlusal plane canting were −4.887 ± 3.126 mm and −0.177 ± 4.029 mm in the experimental and control groups, respectively (P = 0.026). Elastic traction-assisted distraction osteogenesis could improve traction efficiency and facial symmetry.

Delivering increasingly complex software-reliant systems demands better ways to manage the long-term effects of short-term expedients. The technical debt (TD) metaphor has gained significant traction as a way to understand and communicate such issues. Almost 25 years after the term was coined in 1992 by Ward Cunningham, and more than 10 years after the first edition of the TechDebt workshop/conference series, we take a brief look at the past, present, and future of TD.

Vessel wall MR imaging (VWI) is a technique that progressively has gained traction in clinical diagnostic applications for evaluation of intracranial and extracranial vasculopathies, with increasing use in pediatric populations. The technique has shown promise in detection, differentiation, and characterization of both inflammatory and noninflammatory vasculopathies. In this article, optimal techniques for intracranial and extracranial VWI as well as applications and value for pediatric vascular disease evaluation are discussed.