Actual Mode Research Articles

Output-Feedback Control Under Hidden Markov Analog Fading and Redundant Channels

This brief investigates the output-feedback control problem with redundant channels, in which the output measurements may suffer from the Markov analog fading when transmitting through the independent primary channel and redundant channels. The actual channel mode obeys a two-state time-homogeneous Markov chain, and the expectation of fading amplitude in the good mode is much higher than the one in the bad mode. The mode detectors are employed to estimate the status of both the primary and redundant channels, by which the better measurement signals may be selected for the controller. Thus, a token-dependent output-feedback controller is constructed, and then, the stability condition is obtained via the actual mode-dependent Lyapunov function method. Finally, the proposed output-feedback control scheme is applied to an operational amplifier (OPA) circuit under the hidden Markov analog fading channels.

Challenges in Behaviour Modelling of Mode Choice Model - A Peek into Indian Scenario

Mode choice model is one of the crucial steps in the process for Transportation demand modelling. It fore-tell the share of trips attracted to public transportation. Mode choice models compacts very closely with the human choice making behaviour and this continues to attract researchers for further exploration of individual choice making process. The objective of this paper is to observe keenly on the challenges that a modeller will face in Indian scenario. A variety of models are available for prediction. But with the close review it is observed that all these models work either at aggregate level or disaggregate level which works on certain assumptions. This is definitely not going to reflect the actual mode choice behaviour. The particular characters that makes a difference from the world scenario discussed in this paper are diversity in decision making of individual, diversity in socio-economic characteristics, pride and prejudices in mindset that affect the false representation of data, concept of ridesharing and the inhibition in acceptance of the same, travel distance and mode availability in urban and rural scenario. It can be concluded that selecting a model that depict the true nature of commuter is a challenging process. The well-known models available can be trained and calibrated to suit to the need of Indian scenario. Use of machine learning and data mining could be a very useful tool in this model building as all the required changes can be incorporated efficiently

SYSTEM OF CONTROL OF OPERATING MODES OF ELECTRIC TRACTION NETWORKS ON THE BASIS OF FUZZY DESCRIPTION OF THEIR CONDITION

Given the need to save energy and reduce the cost of passenger transport on urban electric transport, the greatest effect (from 5 to 15%) is achieved through the introduction of comprehensive information technologies based on rational modes of traction of electric rolling stock and traction and external power supply. The criterion for assessing the modes of operation of power supply systems of urban electric transport is the energy consumption of traction substations, which reflects most of the influencing factors, including the inseparable relationship of traction and external power supply systems. An approach to the implementation of energy-saving technologies of traction power supply of urban electric transport is proposed, which uses fuzzy models and methods of representation for analysis and selection of controls. It is proposed to implement the control of the power supply system operation modes and the selection of modes on the basis of a vague description of their states. When forming the rules, the following parameters are set: deviation of the daily number of transported passengers on the i-th interstation zone of the two-track section, for the characterization of which the values ​​of fuzzy values ​​"lag (strong, weak, absent)" and "advance (absent, weak, strong)" deviation of daily active energy losses for the substation zone and with the values ​​"strong, absent, weak"; the difference between the daily energy consumption of the i-th substation zone, for the actual mode of operation of the power supply system and the reference mode of uniform loading of the power supply system. When constructing a control model in the form of fuzzy rules, each fuzzy characteristic is approximated by N fuzzy quantities with triangular membership functions. For the fuzzy characteristic the minimum and maximum values ​​of an interval in which there are its admissible values ​​are set. Approximate quantities have a triangular degree of belonging: the vertex lies in the center, it corresponds to the degree of belonging 1, and the other two vertices - on the sides of it with degrees of belonging 0. The fuzzy conclusion is based on the rule of fuzzy Mamdani implication. The constructed base of fuzzy rules, which replaces the model of modes of the power supply system, can be used as a guide to the energy dispatcher to select control for the next time period, taking into account the conditions of uncertainty. The principles of formation of algorithms and filling of databases and knowledge of expert systems are developed and problems of maintenance of modes of energy saving in systems of traction power supply of city electric transport are solved. The proposed algorithms for creating databases of expert systems can be implemented after the modernization of power supply control systems based on new integrated systems. Expert systems must be included in the software of the automated workplace of the energy dispatcher. Their inclusion is planned after introduction of new microprocessor systems of telemechanics of regional control points.

Development of a core outcome set for effectiveness studies of breech birth at term (Breech-COS): A systematic review on variations in outcome reporting

Women pregnant with a breech-presenting fetus at term are at an increased risk of adverse outcomes. Although the most common intervention is planned delivery by caesarean section, this is not always possible or desirable. Comparing alternative interventions is difficult due to heterogeneity in reported outcomes and their measurements. Additionally, the evidence, particularly for women in labour with a breech-presenting fetus, is very low quality, with several outcomes viewed as critical and important to decision-making not reported at all. There is a need to develop a core outcome set of minimum outcomes in all studies evaluating the effectiveness of interventions to improve outcomes associated with term breech birth (Breech-COS).Our objectives were to (1) identify outcomes currently reported in effectiveness studies of breech birth at term using a systematic review of the literature; (2) assess the methodological quality of outcome reporting in the included studies; and (3) engage with members of an established Patient and Public Involvement (PPI) group about the results, to help frame our understanding from the perspective of service users.We searched three databases (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials) for all effectiveness studies associated with vaginal breech birth published in English between 2000 and 2020. Two reviewers independently screened and extracted the data. Outcomes were categorised into neonatal, maternal, features of labour, and long-term maternal and hierarchy of outcome classification (primary, secondary, part of composite, or undesignated). Frequency of reporting was calculated for each. An adapted methodological assessment was done for each study investigating whether primary and secondary objectives were clearly stated and defined. The results of the systematic review were then discussed with a PPI group to consider importance and relevance to service users.A total of 211 outcomes were extracted from 108 included studies, comprising of short (43) and long-term (39) neonatal, short (54) and long-term (39) maternal and features of labour (36) outcomes. The most frequently reported outcome in each category was: APGAR score at 5 min, developmental vulnerability/neurological morbidity, maternal mortality, urinary incontinence, and actual mode of birth respectively. Long-term outcomes were infrequently reported in the included studies, with outcomes for future pregnancies not reported at all, although these were each deemed important by service users. There was a lack of consensus in definition and measurement of outcomes, with only 36% of the included studies having clearly stated primary and secondary objectives.The observed heterogeneity in reported outcomes, lack of consensus in definition and measurement, as well as desire expressed by service users to have robust risk statistics for outcomes important to them highlights the need to develop a core outcome set for evaluating effectiveness studies of breech birth at term. A Breech-COS will enable useful synthesis of evidence and contribute to supported decision-making for women pregnant with a breech-presenting fetus at term.

Transportation mode choice behavior with recommender systems: A case study on Beijing

Understanding and predicting mode choice behavior in urban areas is an ongoing challenge, with several factors identified in past studies, e.g. built-environment, household statistics, trip properties, and many models being developed, e.g., regression and nested logit models. Existing research studies are predominantly designed around stated preferences surveys on small subsets of a population. The massive use of smartphones and route recommendation systems, however, offers the possibility of interacting with users, opening the potential to better understand and influence mode choice behavior, compared to sole offline analysis.This study explores the ability to predict travelers’ mode choice behavior in Beijing based on a collection of 300,000 recommended transportation alternatives from Baidu. The unique context of Beijing, with its enormous congestion and excessive penetration of smart phones, provides a unique view on actual transportation mode choice at a large scale; and behavioral changes induced by mobile communication technologies. We use machine learning techniques to identify the effects of driving variables, including transportation mode accessibility, weather conditions, alternative trip costs, and time of day. We find robust evidence supporting the observation that users preferably select the first-ranked alternative provided by the route recommendation system. This observation should be exploited further by transportation policy-makers to guide users towards greener and environmental-friendly transport modes.

Study on Resistance Coefficient Monitoring of Shallow Hydraulic Tunnel

The acquisition of elastic resistance coefficient is crucial for the design of shallow hydraulic tunnel. In this paper, the resistance coefficient of the tunnel in the test section of the South Main Canal Project is monitored and analyzed. Considering the actual load mode of the tunnel lining, the load value acting on the lining is measured by the measurement instrument on the spot, and the elastic resistance acting on the tunnel lining is obtained. The elastic resistance coefficient acting on the tunnel lining is obtained through the deformation around the tunnel on the measuring side. The research conclusions and methods can provide reference for the support design of shallow hydraulic tunnel in loose soil layer.

Effect of seat-type abutment load path and failure mode on seismic response of straight ordinary bridges

The simplified modeling and analysis procedures commonly used in the design and assessment of bridges utilize one-dimensional (1D) spine elements and springs. These procedures have been well vetted for columns and some capacity-protected members, such as the girders. However, the abutment also contributes to the lateral load resisting system, and the simplified models may not capture the actual load path, failure modes, or dynamic response of either the bridge system or the abutment itself. This paper identifies through static three-dimensional continuum modeling the load path, component contributions to subsystem resistance, and failure modes that should be used in simplified modeling approaches of seat-type abutments. The consequences of common modeling assumptions and simplifications on bridge design and assessment were determined by comparison with 1D simplified models. It was found that the use of modeling simplification substantially underestimates the subsystem resistance. The effect of abutment characteristics, including stiffness and strength in the longitudinal and transverse directions, on nonlinear dynamic bridge seismic demand prediction were investigated with reduced order dynamic models. The increase in abutment stiffness and strength reduces the bridge system’s displacements and increase forces significantly.

Analysis of the Deviation Factors between the Actual and Test Fuel Economy

The Worldwide harmonized Light duty Test Procedure saw its light first as the United Nations Economic Commission for Europe Global Technical Regulation in 2017. However, it remains unclear how much the deviation is between the actual and test fuel economy. In this study, we analyzed the deviation between the actual and test (JC08 and WLTC) fuel economy and examined how well regional characteristics such as average travel speed and temperature could explain the deviation using 182–1035 drivers and 19–52 car models data in Japan. As a result, (1) more than a 30% discrepancy was observed between the actual and JC08 mode test fuel economy, and the higher the test fuel economy, the larger the deviation; (2) regarding WLTC mode fuel economy, the deviation is 19% and constant regardless of the test fuel economy; (3) average travel speed and temperature can explain approximately 8% of the discrepancy.

Force analysis of the redundantly actuated parallel mechanism 2R[formula omitted]R+P considering different control methodologies

In the problem of driving forces/torques distribution of the redundantly actuated parallel mechanisms (PMs), although numerous optimization analysis methods, including the minimum input torque method and minimum energy consumption method have been proposed so far, however, the actual control modes of the actuators were not taken into account among the existing methods for the above problem. Therefore, the present study comprehensively considers both the elastic deformation and actuator’s displacement of each limb, proposes the idea of ”displacement coordination” and establishes the overall displacement coordination equations of the mechanisms. Three different control methodologies of the redundantly actuated PMs, including the full-position methodology, hybrid position–force control methodology and full-force methodology, are studied. For each control methodology, the correlation among the driving forces/torques, actuators’ displacements, external loads and limbs’ stiffness are discussed. An experimental platform of a redundantly actuated PM is built, and the corresponding test investigations for three control methodologies are conducted. In the present study, different control methodologies of the redundantly actuated PMs are considered for the first time, the principle of the dynamic coordination distribution is revealed in different methodologies, which have important reference values for design of coordinated motion control strategy of such kind of mechanisms.

On the efficiency of the control of the circulation of hot water

PURPOSE. Perform analysis of the actual heat energy consumption for cold water heating for the hot water utility to the approved standard. Compare different methods of flow control in circulation pipelines of hot water supply systems. Identify ways to improve the efficiency of hot water systems. METHODS. The passive engineering experiment was used to study the operating modes of hot water supply systems of several groups of houses, in which various methods of regulating water consumption in hot water supply systems are implemented. Data collection was carried out using the online system of control and commercial accounting of energy resources. RESULTS. Existing hot water supply systems in residential buildings of Ulyanovsk were inspected under various methods of flow control in circulation pipelines. Features of static and dynamic load control of hot water supply systems were investigated. Analysis of influence of methods of control of thermal load of hot water supply systems on their actual heat consumption was performed. The possibility of bringing the actual operation mode of hot water supply systems to the standard value, on the basis of which consumption is calculated, is estimated. CONCLUSION. Known methods of load control in hot water supply systems and their actual operating conditions do not allow to reach the level of heat consumption that meets the established standards. Conclusions were drawn on the need to revise the regulated indicators of hot water quality and to adjust the method of calculating consumption in hot water supply systems.

Computer simulation and full-scale measurements of the load flow in a functioning heating network

The article aims to identify patterns in the distribution of heating energy to consumers with a varying availability of regulation equipment under real conditions of a central heating network, as well as to compare the results of computer simulation with full-scale measurements. For computer simulation, well-known mathematical methods for calculating the load flow in hydraulic circuits were used. Experimental studies of the operation modes of heat supply systems were carried out using the data of the control and monitoring systems of thermal power plants using the Siemens Simatic PCS7 software, a Portaflow 300 ultrasonic flow meter, stationary electromagnetic flow transducers, verified and certified manometers and thermometers. The graphs of the actual hydrodynamic modes of the heating network under study were obtained at outdoor air temperatures from +8 to -37°C, as well as under abnormal conditions (temperature drop in the supply pipeline and pressure drop at the heating network input). It was proposed to use jointly the simulation by means of the JA_Net software and full-scale measurements of the thermohydraulic operating modes of a centralised heat supply system, whose consumers have a various degree of regulation equipment. It was shown that the proposed complex method of qualitative and quantitative assessment of the efficiency of district heating networks makes it possible to identify the features of control of their hydraulic modes when connecting new consumers with a varying degree of automation. According to the obtained characteristics of changes in the flow rate of the coolant in the consumers’ internal systems depending on the pressure drop at the tie-in point, the lack of response to emergency situations on part of the consumers whose heat supply systems are equipped with the means of qualitative and quantitative regulation of the heat load, is associated with the process of automatic adjustment of the degree of opening of flow controllers and control valves at individual points. In future work, we will develop guidelines for levelling the imbalance of the heating network under the conditions of uneven provision of facilities with automation equipment when implementing projects for the complex modernisation of heat consumers or connecting new facilities to existing heat supply networks.

554 Successful planned vaginal delivery of triplets: a systematic review and meta-analysis

To evaluate the success of vaginal delivery (VD) of all three triplets when vaginal birth was attempted. A systematic review of peer-reviewed English language articles concerning women who planned for VD of triplets was conducted using PubMed, Scopus, and Cochrane libraries. All studies that reported actual mode of delivery for all three triplets were included. The primary outcome was the incidence of successful VD for all triplets in women who planned a vaginal birth. Secondary outcomes were maternal and neonatal outcomes based on the intended and actual mode of delivery. 19 studies (n= 694 triplet gestations) met inclusion criteria. The studies were heterogenous (I2=91.1%, CI 87.6%-93.6%). The incidence of VD for all three triplets among those attempting vaginal birth was 79.8% (95% CI 68.2%-89.2%). Women who attempted VD were younger than those who had planned cesarean (31.3 vs 32.6 years, MD -0.26, 95% CI -0.41, -0.11). Multiparous women were more likely to attempt VD (OR 1.84, 95% CI 1.32-2.58). Maternal outcomes were not reported for women who had a successful VD versus women who were unsuccessful or had a scheduled cesarean. There was increased incidence of necrotizing enterocolitis among infants born to women who attempted VD compared to those who had a scheduled cesarean (OR 2.36, 95% CI 1.02-5.48). The mean gestational age (GA) was lower among triplets who attempted VD compared to those who had a scheduled cesarean (32.6 vs 33.6 weeks, MD -0.92, 95% CI -1.87-0.04). There was increased neonatal mortality among those with a successful VD compared to the cesarean group (OR 5.55, 95% CI 2.0-15.3); however, this analysis included a study from 1989 in a low-resource setting, which may not reflect current practices. When this paper was excluded, there was no difference in neonatal mortality between groups (OR 2.57, 95% CI 0.39-17.1). The optimal mode of delivery for triplets remains unclear. This study may assist in counseling patients regarding success rate and outcomes if a vaginal birth is desired.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Benchmarking failure mode and effects analysis of electronic brachytherapy with data from incident learning systems

PurposeFailure modes and effects analysis (FMEA) is a prospective risk assessment tool for identifying failure modes in equipment or processes and informing the design of quality control systems. This work aims to benchmark the performance of FMEAs for electronic brachytherapy (eBT) of the skin and for breast by comparing predicted versus actual failure modes reported in multiple incident learning systems (ILS). Methods and MaterialsTwo public and our institution's internal ILS were queried for Xoft Axxent eBT-related events over 9 years. The failure modes and Risk Priority Numbers (RPNs) were taken from FMEAs previously performed for Xoft eBT of nonmelanoma skin cancer and breast intraoperative radiation therapy (IORT). For each event, the treatment site and primary failure mode was compared with the failure modes and RPNs from that site's FMEA. Results49 events involving Xoft eBT were identified. Thirty-one (63.3%) involved breast IORT, and 18 (36.7%) involved the skin. Three events could not be linked to an FMEA failure mode. In 87.7% of events, the primary failure mode ranked in the FMEA top 10 by RPNs. In 83.3% of skin events, the failure modes ranked in the top 10 by RPN or severity. In 90.3% of IORT events, the failure modes ranked within the top 10 by RPN or severity. ConclusionsEvaluating FMEA failure modes against ILS data demonstrates that FMEA is effective at predicting failure modes but can be dependent on user experience. ILS data can improve FMEA by identifying potential failure modes and suggesting realistic occurrence, detectability, and severity values.

Accidental Hanging between ventilation window and air condition unit a very unusual death- A case report

Hanging is a form of strangulation meaning application of external pressure on the neck, either by a ligature or by any other material and the force of constriction to the neck is provided by the gravitational pull to the body. Hanging is often suicidal, homicidal (lynching) and rarely accidental. A boy of about 18 years of age was found hanging by the neck, and neck being caught in between window pan and external AC (air condition) unit. It was a complete hanging with no part touching the ground. Accidental hanging is uncommon, though few cases are reported in children and some in autoerotic context in adults. The study of the death scene, the forensic autopsy findings, the toxicological analysis and the study of the circumstances of death are essential to evaluate the actual mode and manner of death.

Crack path tracking using DIC and XFEM modelling of mixed-mode fracture in wood

A wedge split test in mode I and mixed-mode was designed and performed for wood at structural component scale. The displacement fields around cracks during propagation were recorded and analysed to provide information on crack tip position, the composition of deformation modes, resistance to fracture propagation, and separation of the crack lips. The data were fed into a non-linear numerical finite element model. A cohesive zone model based on the eXtended Finite Element Method was applied for mixed-mode fracture in 2D rectilinear orthotropic materials. Extrinsic exponential traction-separation laws for modelling mixed-mode splitting of wood from Norway spruce along the grain were calibrated to experimental crack data. The chosen model captures well the damage initiation and crack propagation in wood along the grain. The simulation results show the importance of initial crack length and actual mode composition as model parameters.

Multi-Information Fusion-Based Hierarchical Power Generation-Side Protection System

With renewable power sources and new topology structures being widely introduced into the power system, the current local information-based power generation-side protection cannot fully guarantee the protection performance and the safety coordination with the power grid. This paper proposes an improved hierarchical protection system on the power generation-side. The proposed system takes advantage of the fusion of multi-information provided by the system, station and local layers. The system layer provides the information such as system voltage control and power regulation demand, so that the generation-side protection and control system can adapt to the system operation mode and power regulation demand. The station layer realizes the coordination of the protection principle and action strategy among the related units through information interaction with the power grid, the automatic control system and the local layer protection. The local layer introduces the condition monitoring information and more abundant protection information to enhance the protection performance and master the generation units’ safety condition. To illustrate the hierarchical protection system construction method and actual application mode, the multi-information fusion-based comprehensive local layer protection method and the multi-generators information fusion-based hierarchical protection method are taken as examples. Case analysis shows that the proposed methods can reflect more slight internal fault forms and can adaptively determine the protection action characteristic and tripping strategy according to the system operating conditions and other generators’ fault conditions, which effectively improve the protection sensitivity and coordination capability. To provide reference and inspiration for follow-up research, the hierarchical protection system construction mode, communication technology and research approaches of new protection methods are further pointed out.

Output-only modal analysis for non-synchronous data using stochastic sub-space identification

The stochastic subspace identification (SSI) method has been recognized as the most dominant and popular system identification technique in the time domain. Nevertheless, it cannot cope with the non-synchronicity of dynamic response measurements that happens sometimes in structural health monitoring practice. To overcome this, this study proposes a strategy for the SSI algorithm to realize system identification from non-synchronous dynamic response measurements. The modal identification is carried out in a pairwise manner by pairing a time-shifted signal with a common reference signal. The state space model is employed to fit the pair of reference and time-shifted signals and the SSI algorithm is exploited to extract the modal parameters. The core of the strategy is the tactical usage of the mean phase deviation (MPD) of the mode for seeking out the actual time lag as well as the actual mode shape components simultaneously. By so doing, the strategy fulfills integrated time lag estimation and modal extraction for non-synchronous dynamic response measurements. Furthermore, the strategy also overcomes the difficulty to determine the model order with the use of the stabilization diagram and reduces the computational cost substantially with the help of the periodicity of the MPD. To examine the performance of the strategy, intensive validations are conducted by making use of the non-synchronous acceleration measurements of the Jiangyin Bridge subjected to a ship collision and the artificially misaligned acceleration measurements of the Canton Tower struck by an earthquake. Both the time lags and the mode shapes identified by the strategy can be well validated, indicating that the proposed strategy is competent for modal identification of non-synchronous dynamic response measurements.

Shear Experiments of Prestressed Concrete Bridge Girders

For the assessment of existing slab-between-girder bridges, the shear capacity and failure mode are under discussion. Previous research showed that the static and fatigue punching capacity of the slabs is sufficient as a result of compressive membrane action. The girders then become the critical elements. This research studies the shear capacity of prestressed concrete bridge girders. For this purpose, four (half) girders were taken from an existing bridge that was scheduled for demolition and replacement and tested to failure in the laboratory. Two loading positions were studied. The results show that there should be a distinction between the mode of inclined cracking and the actual failure mode. In addition, the results show that for prestressed concrete girders, the influence of the shear span-depth ratio should be considered for shear span-depth ratios larger than 2.5. These insights can be used for the assessment of existing slab-between-girder bridges in the Netherlands.

Who indicates caesarean section? A cross-sectional survey in a tertiary level maternity on patients and doctors’ profiles at childbirth

Introduction. Given how common caesarean section (C-section) has become, our objectives are: 1) to analyze the way Romanian women want to give birth, and 2) to draw a profile of patients and doctors in whose case the actual birth method has changed from the preferred method after admission in the labor ward. Materials and method. We conducted a statistical analysis based on an observational, analytical and cross-sectional survey in a tertiary level maternity from Romania. Results. We calculated an increase of almost 58% in the actual childbirth mode against preferred childbirth by caesarean section, rather difficult to justify based only on medical emergencies. 31.8% preferred natural birth, and 68.2% preferred C-section. The profiles of patients with concordant and nonconcordant delivery modes are different and indicate a statistically significant difference between the preference for delivery and the actual birth method. Doctors’ profiles show that specialists and consultants attend the largest share of nonconcordant births, while residents and young senior doctors attend mostly vaginal births. Conclusions. We emphasize health system particularities in Romania as triggers of high C-section rates that favor women’s preferences against C-section medical indication. Improving patients’ confidence in the healthcare system, built on competence and fitted hierarchical team position, may lead to choosing the optimal way of birth for childbirth safety and pain control.

Unit Commitment with Tunable Frequency Response from Wind Turbine Generators

Based on the natural inertia on the rotors, wind turbine generators can provide both inertia response and primary frequency response to support the system frequency stability. In this paper, by considering the coordinated optimization of frequency response, a unit commitment with tunable frequency response from wind turbine generators is proposed. The relationship between inertia response and primary frequency response is analyzed. A frequency response correlation constraint is proposed to eliminate the second frequency nadir. Considering the system frequency stability constraints and the feasible region of frequency response provided by wind turbine generators, a security-constrained unit commitment model with tunable frequency response is established. According to the actual operation mode of the power system, a bi-level algorithm is adopted to calculate the frequency response parameters of wind turbine generators. The simulation result of the GB 2030 system demonstrates that the proposed method can reduce operating costs while ensuring system stability.