bluuebunny/crossref_metadata_2025_split huggingface dataset:
The frequency converter with autonomous inverter output power flow research for various working modes
Authors: Vasiliev B U , Zyrin V O 
Published: November 2019

Abstract
Energy characteristics of electric drives with frequency converters are generally determines with unit working mode and effectiveness of autonomous inverter (AI) operating, which set the voltage level for the actuating machines windings. Also, the structure of output power flow, consumed by actuating engine has been determined in dependence with AI mode. These facts explain the actuality of researches in the field of semiconductor converter working mode, it output power and control methods. The two methods of autonomous inverter operating have been investigated: pulse-width modulation and phase modulation. The paper shows that during pulse-modulation mode voltage distortion factor decreases, but the current distortion factor increases. Output phase current and voltage hodographs show that resultant vectors of this coordinates during PWM mode moves with higher smoothness, but in phase modulation mode it moves in steps. Power distortion for PWM mode is higher, active power share in the total power structure decrease. It leads to higher energy consumption during AI operating with an equal load. For the power consumption decreasing and higher energy efficiency, it recommended using energy saving control algorithms, providing smooth resultant output voltage hodograph shifting and higher voltage distortion factor value.
Network allocation of BESS for improving rotor angle stability
Authors: Diaz V , Alvarez R , Rahmann C 
Published: November 2019

Abstract
This paper presents a novel methodology for an efficient allocation of Battery Energy Storage Systems (BESS) in order to improve rotor angle stability of power systems. The proposal uses a genetic algorithm (GA) specifically designed to solve the allocation problem. The use of GA enables us to evaluate each candidate using time-domain simulations in a set of critical operating conditions and contingencies. This in turn allows us to obtain an accurate estimation of the impact that different BESS allocations may have in the stability of the system. Results from a network based on the IEEE 39-bus New England System demonstrate the benefits of our proposed methodology in terms of improvements in the rotor angle stability that can be achieved and its practical implementation in real-world power systems.
Influence of excess eddy current core losses of saturable reactor on the process of semiconductor valve turn-on
Authors: Safonov E , Lozinova N 
Published: November 2019

Abstract
In this article the transient process was analyzed when the semiconductor valve turn-on with a new modernized equipment of the Vyborg HVDC scheme. It was found that transient processes occur at high frequencies of about 50-60 kHz. During high-frequency transients when the valve turn-on current can reach zero and negative values. This oscillation can lead to premature valve turn-off and even to its destruction, depending on the switching conditions. The paper deals with issue of damping of the turn-on high-frequency current oscillation witch can be achieved by effective eddy-current resistance due to excess eddy current magnetic core losses of the saturable reactors. Calculation energy losses in thin structures of laminated magnetic core of the saturable reactor were carried out using obtained data of transient process and Comsol Multiphysics modeling. This gave a numerical estimate of the effect of these losses on the transient process. In terms of obtaining data modificated equivalent electrical circuit was proposed. This modification allows to estimate the influence of excess eddy current core losses of saturable reactor on the semiconductor valve turn-on.
Multi-objective voltage control and reactive power optimization based on multi-objective particle swarm algorithm
Authors: Mamdouh K A , Shehata A A , Korovkin N V 
Published: November 2019

Abstract
This paper presents multi-objective particle swarm optimization (MOPSO) for voltage control and reactive power optimization. The optimization objective is to minimize active power loss and improve power system voltage profiles can be achieved by controlling a number of control variables such as generator voltages, transformer tap ratios and shunt capacitors, etc. A Fuzzy membership function is used to obtain the best compromise solution out of the available Pareto-optimal solutions. The results MOPSO are compared to the multi-objective genetic algorithm (MOGA), genetic algorithm (GA) and Particle Swarm Optimization (PSO). The IEEE 14 bus and IEEE 30 bus standards systems were used as test systems to demonstrate the applicability and efficiency of the proposed method.
Simulation model of the electrical complex of auxiliary equipment of an oil and gas production enterprise
Authors: Nurbosinov D , Tabachnikova T , Bashirov R , Bashirov R , Batanin Alexander 
Published: November 2019

Abstract
In this article we define the problem, formulate the theme and justify the relevance of the tasks to be solved, which depend on the object under study. The object under study was determined and the structure and basic elements were analyzed. It was found that an auxiliary transformer and from eight to ten outgoing lines are connected to one section of bus of a power transformer of the field substation. Mathematical models of electrical systems of a field substation and a pumping station for transporting oil flows with shop transformers, individual, node and centralized compensating installations have been developed. In mathematical models which take into account the change in the volume of transported oil into a common pipeline, asynchronous electric motors of pumping units with a capacity of 75, 132 and 160 kW with low-voltage frequency converter are considered. Using the MATLAB Simulink software package, we developed mathematical models for 75, 132 kW (132 and 160 kW) electric drives of pumping units. These models take into account emergency operation, i.e. when two pumping units operate from the same power source. The study of the operating modes of the electrotechnical complex of a booster pump station during direct start-up from the electrical network was carried out using its simulation model developed in the PSCAM software package. The article presents the simulation results in the form of graphs showing relationships between frequency buildup, electromagnetic and dynamic moments and the stator current of the asynchronous motor. Scientific novelty of the present work is in the developed mathematical and simulation models which take into account parametric perturbations in external and internal distribution electrical networks, and allow one to determine the energy parameters of operating modes in all sections and elements of the outgoing line, taking into account reactive power compensation in transient and steady-state conditions.
Integration of renewable energies in the electricity grid from energy storage plants in disused mining structures
Authors: Menéndez J , Loredo J 
Published: November 2019

Abstract
Energy Storage Plants (ESP) can be considered an alternative to solve the intermittency problems associated to variable renewable energy (VRE), such as wind and solar photovoltaic. This paper explores the use of closed mines as underground reservoir for Underground Pumped Storage Hydropower (UPSH) and Compressed Air Energy Storage (CAES) plants. Investment cost and stored amount of energy are compared in both technologies. Mining structures in disused coal mines in NW Spain have been selected as a case study to analyse the potential of energy storage in disused mining structures. Pumped Storage Hydropower is the most mature large-scale energy storage technology that dominates both the total installed power capacity and the energy storage capacity. An alternative to UPSH plants could be CAES plants, which are systems to store energy in the form of compressed air, and work in a similar way to conventional gas turbines. Abandoned salt cavern or closed coal underground mines are typically used as underground compressed air storage, giving new uses to the infrastructure of abandoned mines. The results obtained show that 130 MW of electrical power could be installed in UPSH and CAES plants in closed mines with an investment cost of about 225 M€.
The impact of current transformer saturation on the performance of differential protection of generators and motors at frequencies below 50 Hz
Authors: Bessolitsyn A V , Golgovskich A V , Novikov A V 
Published: November 2019

Abstract
At present, low-frequency modes are widely used in the operation of electric generators and engines. Relay protection should ensure the implementation of its functions even at a frequency below the rated by tens of percent. Signals from current transformers go to inputs of current relay protection devices, and their performance deteriorates significantly at frequencies below industrial. The article experimentally investigates the impact of the core saturation of a current transformer that occurs at low frequency on the value of the differential current in the differential relay protection circuit of a generator or motor. The authors analyze how the burden of current transformers, the value of the current and its frequency affect the value of the differential current. They show the possibility of both a false response and a failure in the operation of the differential protection at low frequency. Moreover, the authors give practical recommendations on ensuring emergency protection of equipment at a frequency below 50 Hz.
Large eddy simulation calculated flame dynamics of one F class gas turbine combustor
Authors: Yang Yang 
Published: November 2019

Abstract
Thermoacoustics in modern gas turbines is always accompanied by lean premixed combustion. The flame transfer function (FTF) is an important quantity that can quantify thermoacoustics. However, the FTF is always considered as a black box and used in the final development phase. This work applied proper orthogonal decomposition (POD), which is normally used in hydraulic instability analysis. Results obtained by comparing the frequency response and mode shape indicated the flame was stable even in the presence of coherent structures in the flow field. The transfer function between the first three modes and overall heat release rate (HRR) was calculated to confirm the relationship between mode and the FTF. Results indicated that the potential risk of pulsation did not originate from flow instability.
Review of Russian research in the field of wind energy
Authors: Kangash A I , Maryandyshev P A , Zatsarinnaya Yu N , Volkova M M 
Published: November 2019

Abstract
The use of renewable energy sources is becoming a priority for states due to growing environmental problems. Wind is one of the most sustainable renewable energy sources. In Russia, interest in wind energy has been growing in recent years. This paper is a review of the research on wind in Russia, the main objective is to show the level of development of the scientific base, as well as to consider the main topics, articles, research groups and completed projects, and make a comparison with world scientific works.
Self-monitoring of Blood Pressure in Patients With Hypertension-Related Multi-morbidity: Systematic Review and Individual Patient Data Meta-analysis
Authors: Sheppard J P , Tucker K L , Davison W J , Stevens R , Aekplakorn W , Bosworth H B , Bove A , Earle K , Godwin M , Green B B , Hebert P , Heneghan C , Hill N , Hobbs F D R , Kantola I , Kerry S M , Leiva A , Magid D J , Mant J , Margolis K L , McKinstry B , McLaughlin M A , McNamara K , Omboni S , Ogedegbe O , Parati G , Varis J , Verberk W J , Wakefield B J , McManus R J 
Published: November 2019

Abstract

BACKGROUND
Studies have shown that self-monitoring of blood pressure (BP) is effective when combined with co-interventions, but its efficacy varies in the presence of some co-morbidities. This study examined whether self-monitoring can reduce clinic BP in patients with hypertension-related co-morbidity.

METHODS
A systematic review was conducted of articles published in Medline, Embase, and the Cochrane Library up to January 2018. Randomized controlled trials of self-monitoring of BP were selected and individual patient data (IPD) were requested. Contributing studies were prospectively categorized by whether they examined a low/high-intensity co-intervention. Change in BP and likelihood of uncontrolled BP at 12 months were examined according to number and type of hypertension-related co-morbidity in a one-stage IPD meta-analysis.

RESULTS
A total of 22 trials were eligible, 16 of which were able to provide IPD for the primary outcome, including 6,522 (89%) participants with follow-up data. Self-monitoring was associated with reduced clinic systolic BP compared to usual care at 12-month follow-up, regardless of the number of hypertension-related co-morbidities (−3.12 mm Hg, [95% confidence intervals −4.78, −1.46 mm Hg]; P value for interaction with number of morbidities = 0.260). Intense interventions were more effective than low-intensity interventions in patients with obesity (P &lt; 0.001 for all outcomes), and possibly stroke (P &lt; 0.004 for BP control outcome only), but this effect was not observed in patients with coronary heart disease, diabetes, or chronic kidney disease.

CONCLUSIONS
Self-monitoring lowers BP regardless of the number of hypertension-related co-morbidities, but may only be effective in conditions such obesity or stroke when combined with high-intensity co-interventions.
Default mode network functional connectivity after multiple concussions in children and adolescents
Authors: Plourde Vickie , Rohr Christiane S , Virani Shane , Bray Signe , Yeates Keith Owen , Brooks Brian L 
Published: November 2019

Abstract

The default mode network (DMN), a set of brain regions, has been shown to be affected post-concussion.

Objective
This cross-sectional study aims to elucidate if children and adolescents with multiple concussions demonstrate long-term alterations in DMN functional connectivity (FC).

Method
Participants (N = 57, 27 girls and 30 boys; 8-19 years old, M age = 14.7, SD = 2.8) were divided into three groups (orthopedic injury [OI] n = 20; one concussion n = 16; multiple concussions n = 21, M = 3.2 concussions, SD = 1.7) and seen on average 31.6 months post-injury (range 4.3-130.7 months; SD = 19.4). They underwent a resting-state functional magnetic resonance imaging scan. Parents completed the ADHD rating scale-5 for children and adolescents. Children and parents completed the post-concussion symptom inventory (PCSI).

Results
Anterior and posterior DMN components were extracted from the fMRI data for each participant using FSL’s MELODIC and dual regression. We tested for pairwise group differences within each DMN component in FSL’s Randomize (5000 permutations) using threshold-free cluster enhancement to estimate cluster activation, controlling for age, sex, and symptoms of inattention. FC of the anterior DMN was significantly reduced in the group with multiple concussions compared to the two other groups, whereas there were no significant group differences on FC of the posterior DMN. There were no significant associations between DMN FC and PCSI scores.

Conclusions
These results suggest reduced FC in the anterior DMN in youth with multiple concussions, but no linear association with post-concussive symptoms.
Estimation of error variance via ridge regression
Authors: Liu X , Zheng S , Feng X 
Published: November 2019

Summary
We propose a novel estimator of error variance and establish its asymptotic properties based on ridge regression and random matrix theory. The proposed estimator is valid under both low- and high-dimensional models, and performs well not only in nonsparse cases, but also in sparse ones. The finite-sample performance of the proposed method is assessed through an intensive numerical study, which indicates that the method is promising compared with its competitors in many interesting scenarios.
Server-aided Revocable IBE with Identity Reuse
Authors: Ma Xuecheng , Lin Dongdai 
Published: November 2019

Abstract
Efficient key revocation in Identity-based Encryption (IBE) has been a both fundamental and critical problem when deploying an IBE system in practice. Boneh and Franklin proposed the first revocable IBE (RIBE) scheme where the size of key updates is linear in the number of users. Then, Boldyreva, Goyal and Kumar proposed the first scalable RIBE by using the tree-based approach where the size of key updates is $O(r\log (N/r))$ and the size of every user’s long-term secret key is $O(\log N)$ with $N$ being the number of users and $r$ the number of revoked users. Recently, Qin et al. presented the notion of server-aided RIBE where the size of every user’s long-term secret key is $O(1),$ and users do not need to communicate with Key Generator Center (KGC) during every key updates. However, users must change their identities once their secret keys are revoked as they cannot decrypt ciphertexts by using their revoked secret keys.
To address the above problem, we formalize the notion of RIBE with identity reuse. In our system model, users can obtain a new secret key called the reuse secret key from KGC when their secret keys are revoked. The decryption key can be derived from the reuse secret key and new key updates while it cannot be derived from the revoked secret key and the new key updates. We present a concrete construction that is secure against adaptive-ID chosen plaintext attacks and decryption key exposure attacks under the $\mathsf{ADDH}1$ and $\mathsf{DDH}2$ assumptions in the standard model. Furthermore, we extend it to server-aided RIBE scheme with identity reuse property that is more suitable for lightweight devices.
Health economic evaluation of rivaroxaban in the treatment of patients with chronic coronary artery disease or peripheral artery disease
Authors: Cowie Martin R , Lamy André , Levy Pierre , Mealing Stuart , Millier Aurélie , Mernagh Paul , Cristeau Olivier , Bowrin Kevin , Briere Jean-Baptiste 
Published: November 2019

Abstract

Aims
In the COMPASS trial, rivaroxaban 2.5 mg twice daily (bid) plus acetylsalicylic acid (ASA) 100 mg once daily (od) performed better than ASA 100 mg od alone in reducing the rate of cardiovascular disease, stroke, or myocardial infarction (MI) in patients with coronary artery disease (CAD) and peripheral artery disease (PAD). A Markov model was developed to assess the cost-effectiveness of rivaroxaban plus ASA vs. ASA alone over a lifetime horizon, from the UK National Health System perspective.

Methods and results
The base case analysis assumed that patients entered the model in the event-free health state, with the possibility to experience ≤2 events, transitioning every three-month cycle, through acute and post-acute health states of MI, ischaemic stroke (IS), or intracranial haemorrhage (ICH), and death. Costs, quality-adjusted life-years (QALYs), life years—all discounted at 3.5%—and incremental cost-effectiveness ratios (ICERs) were calculated. Deterministic and probabilistic sensitivity analyses were conducted, as well as scenario analyses. In the model, patients on rivaroxaban plus ASA lived for an average of 14.0 years with no IS/MI/ICH, and gained 9.7 QALYs at a cost of £13 947, while those receiving ASA alone lived for an average of 12.7 years and gained 9.3 QALYs at a cost of £8126. The ICER was £16 360 per QALY. This treatment was cost-effective in 98% of 5000 iterations at a willingness-to-pay threshold of £30 000 per QALY.

Conclusion
This Markov model suggests that rivaroxaban 2.5 mg bid plus ASA is a cost-effective alternative to ASA alone in patients with chronic CAD or PAD.
Mapping perspectives of inhabitants and professionals in deprived neighborhoods in the Netherlands
Authors: Dierx J A J 
Published: November 2019

Abstract

Background
People living in deprived neighborhoods have been shown to have several social and health problems such as loneliness, feelings of unsafety, poor diet and overweight, resulting in more sick years (16 years) and shorter life expectancy (6 year; Buck & Maguire, 2015; Murtin et al., 2017). Interventions developed by professionals to reduce health inequalities, seem to have little long term effects possibly due to interventions not matching the perspectives of people in deprived neighborhoods. The present study is performed to map possible differences in perspectives between inhabitants and professionals in deprived neighborhoods using the Triple-I method.

Methods
The Triple-I method as qualitative research tool (Boonekamp, Dierx & Jansen, in publication) was used to gain insight in how inhabitants (N = 12) and health and social professionals (N = 18) percieve the deprived neighborhood. Inhabitants and professionals were in separate Triple-I sessions that all took place in a community center within the neighborhood.

Results
Results show that both inhabitants and professionals want to create more self-reliance of the inhabitants. However, professionals mention their skills in organizing and bringing logic in the actions of inhabitants whereas inhabitants mention their own ability to organize activities themselves. In addition where both mention ‘togetherness’ as topic, inhabitants refer to this as ‘meeting each other’, whereas professionals talk about ‘constructing powerful networks with inhabitants and other professionals’. According to professionals these networks can ‘create feelings of safety’, which inhabitants perceive as a result of ‘clean and green surrounding’.

Conclusions
This research corroborates the suggestion that professionals and inhabitants percieve their neighborhood differently. Interventions reducing health inequality might be more effective when approached from the perspective of and even developed and executed by the target group.

Key messages
Triple-I method is useable in asset mapping of inhabitants and professionals in deprived neighborhoods in the Netherlands. Triple-I mehtod is useable in stimulating physical activities and health in neighborhoods.