bluuebunny/crossref_metadata_2025 huggingface dataset:
A role for the orphan nuclear receptor TLX in the interaction between neural precursor cells and microglia
Authors: Kozareva Danka A. , Moloney Gerard M. , Hoban Alan E. , Rossini Valerio , Nally Ken , Cryan John F. , Nolan Yvonne M.
Published: February 2019

Microglia are an essential component of the neurogenic niche in the adult hippocampus and are involved in the control of neural precursor cell (NPC) proliferation, differentiation and the survival and integration of newborn neurons in hippocampal circuitry. Microglial and neuronal cross-talk is mediated in part by the chemokine fractalkine/chemokine (C-X3-C motif) ligand 1 (CX3CL1) released from neurons, and its receptor CX3C chemokine receptor 1 (CX3CR1) which is expressed on microglia. A disruption in this pathway has been associated with impaired neurogenesis yet the specific molecular mechanisms by which this interaction occurs remain unclear. The orphan nuclear receptor TLX (Nr2e1; homologue of the Drosophila tailless gene) is a key regulator of hippocampal neurogenesis, and we have shown that in its absence microglia exhibit a pro-inflammatory activation phenotype. However, it is unclear whether a disturbance in CX3CL1/CX3CR1 communication mediates an impairment in TLX-related pathways which may have subsequent effects on neurogenesis. To this end, we assessed miRNA expression of up- and down-stream signalling molecules of TLX in the hippocampus of mice lacking CX3CR1. Our results demonstrate that a lack of CX3CR1 is associated with altered expression of TLX and its downstream targets in the hippocampus without significantly affecting upstream regulators of TLX. Thus, TLX may be a potential participant in neural stem cell (NSC)–microglial cross-talk and may be an important target in understanding inflammatory-associated impairments in neurogenesis.
Non‐orthogonal multiple access without channel state information for similar channel conditions
Authors: Xia Wenlong , Meng Qingdang , Tao Qingchuan , Chen Ray T.
Published: February 2019

A downlink non‐orthogonal multiple access with QPSK input constellations based on virtual channel optimisation is presented to address the similar channel conditions scenario. The novel idea is to construct a uniquely decodable sum constellation by maximising the minimum Euclidean distance among the points of the superposed constellation. An optimal angle difference is derived to make the proposed scheme easy to implement. With a fixed angle pair setup, a non‐orthogonal multiple access system without the knowledge of channel state information is proposed. Simulation results are provided to demonstrate the performance of the proposed scheme.
Compact dual‐band bandpass filter using defected SRR and irregular SIR
Authors: Luo Xian‐hu , Cheng Xu , Han Jiang‐an , Zhang Liang , Chen Feng‐jun , Guo Ying‐jiang , Xia Xin‐lin , Deng Xian‐jing
Published: February 2019

A novel miniaturised dual‐band bandpass filter (BPF) based on defected split‐ring resonators (SRRs) and irregular stepped‐impedance resonators (SIRs) is proposed. By applying defected SRRs embedded with eight combinations of three whole or broken grooves, which are formerly used for divination, the passband of 2.35–2.52 GHz with wideband harmonic suppression is achieved for WLAN applications. To create one more passband of 5.09–5.3 GHz, the irregular SIRs are etched inside the defected SRRs. Finally, such a prototype is designed and fabricated with the dimension of only 20 × 20 mm2 (0.27λg × 0.27λg). The measured results of this dual‐band BPF agree well with the simulations verifying the proposed idea.
PreLoc: predicting pedestrian's location and learning unmapped pathways by long short‐term memory model
Authors: Zhong Haolin , Tian Jacky , Yao Chang
Published: February 2019

With increasing popularity of smartphone apps such as fitness assistants, location‐based services, more and more pedestrians now travel in short distances with purposes of leisure, running exercise or social activities. As users move from place to place, the mobile apps capture the data showing the history of change in location in a definite time interval. Given the set of global positioning system (GPS) location points a user has travelled along, this study presents, PreLoc, a system that accurately predicts the user's future location. By preprocessing the raw data, the authors eliminate existing noises and extract valid trajectories from pedestrians or runners. Then the long short‐term memory model is applied to predict the next GPS point that the user will pass through. Meanwhile, PreLoc is able to learn an unmapped pathway based on the trajectory data of mass users that have travelled over this pathway. Experimental results over real‐world dataset show the distance error could achieve about 12 m in residential area, and achieve acceptable distance errors (about 30 m) for other larger and complicated sites. Moreover, they provide real scenarios for unmapped pathway learning.
Analysis of the physical layer security enhancing of wireless communication system under the random mobile
Authors: Zhang Tengyue , Wen Hong , Tang Jie , Song Huanhuan , Liao Runfa , Chen Yi , Jiang Yixin
Published: February 2019

User mobility is a major feature of wireless networks. At present, physical layer security research rarely considers the impact of user mobility on the physical layer security performance in the network. In this study, the authors propose a random mobile user physical layer security model and study the impact of random waypoint movement users on the security performance of the physical layer in wireless networks, in which an artificial noise security scheme under the multi‐antenna transmission model is considered. They derive the closed expression of positive secrecy capacity probability and secrecy outage probability under this model. The results prove that system security is enhanced because of the users’ mobility.
FO improved fast terminal sliding mode control method for permanent‐magnet synchronous motor with FO disturbance observer
Authors: Wu Fei , Li Penghan , Wang Jie
Published: February 2019

This study proposes a fractional‐order (FO) improved fast terminal sliding mode controller for permanent‐magnet synchronous motor speed regulation system. By designing an FO proportional–integral controller for current loops, an FO model between reference q ‐axis current and speed output is proposed. By introducing an FO terminal sliding mode surface, a novel FO terminal sliding mode controller is designed for speed loop to improve the speed tracking performance. The proposed FO controller can make speed reach reference value in finite time. Moreover, it is proved that the control time of the FO sliding mode controller is shorter than integer‐order (IO) sliding mode controller. To further enhance the convergence speed, the fast terminal sliding mode control method is used. Meanwhile, FO disturbance observer is utilised to enhance the disturbance‐rejection ability. The control law of the proposed controller is designed according to Lyapunov stability theorem. Finally, Simulation and experimental results demonstrate the effectiveness, high control performance and high disturbance‐rejection ability of the proposed composite FO controller in comparison with IO controller.
Composite adaptive disturbance observer‐based control for switched stochastic systems with multiple disturbances subject to mode‐dependent average dwell time switching
Authors: Ma Lianfang , Sun Haibin , Zong Guangdeng
Published: February 2019

The problem of composite adaptive disturbance observer‐based control and weighted performance analysis for a class switched stochastic systems with multiple disturbances subject to mode‐dependent average dwell time switching are studied. A disturbance observer and an adaptive updated law are constructed to further design a state feedback controller. Some sufficient criteria are established to check the stability of the switched stochastic systems with multiple disturbances in terms of the multiple Lyapunov function technique. Furthermore, a composite adaptive disturbance observer based‐controller is also given. Finally, two examples are proposed to prove the validity of the obtained results.
Distributed cooperative adaptive state estimation and system identification for multi‐agent systems
Authors: Stegagno Paolo , Yuan Chengzhi
Published: February 2019

In this study, the authors address the problem of composite cooperative state estimation and system identification for linear multi‐agent systems (MASs) under the leader–follower framework. This problem specifies an objective for each follower agent to estimate its local plant state and identify its plant dynamics simultaneously through interacting and communicating with its neighbours. A novel distributed adaptive estimation and identification protocol is proposed, which possesses five important properties to improve existing cooperative approaches: (i) it deals with general linear MASs with a completely unknown agent dynamics, allowing dynamics heterogeneity between the leader and the followers; (ii) it enables simultaneous exact state estimation and accurate system identification of MASs with guaranteed exponential convergence performance; (iii) it utilises only relative measurements from neighbouring agents, but without requiring any knowledge of absolute local plant states/outputs; (iv) it is fully distributed in the sense that its design and implementation do not involve any global information, including the overall network connectivity and the leader's dynamics; (v) exact system identification can be achieved under a cooperative persistent excitation (PE) condition, which significantly relaxes the classical PE condition. Simulation studies have been conducted to demonstrate the effectiveness of the proposed approach.
Representation learning by hierarchical ELM auto‐encoder with double random hidden layers
Authors: Li Rui , Wang Xiaodan , Lei Lei , Wu Chongming
Published: February 2019

Recent research developments of extreme learning machine (ELM) with multilayer network architecture lead to a promising high performance with extremely fast training speed for representation learning. In this work, the authors are dedicated to develop an efficient and expressive representation learning method with hierarchical ELM, and proposing a novel architectural unit named as double random hidden layers ELM auto‐encoder (DELM‐AE). The novel DELM‐AE consists of one input layer, two random hidden mapping layers for encoding feature, and one output layer for decoding feature. When stacking DELM‐AE in the hierarchical structure, they can construct an H‐DELM model, where the input of the current AE is the feature representation learned by the previous one, but the output is identical to the original input information and is not the input. Hence, the H‐DELM can reproduce the original input data as much as possible to learn more expressive and compact feature. They validate their method on various widely public datasets, and the results demonstrate that H‐DELM can bring significant performance improvements in terms of classification accuracy and robustness compared with existing relevant multilayer ELM and other deep learning algorithms at a slight computational cost.
Nine‐phase six‐terminal pole‐amplitude modulated induction motor for electric vehicle applications
Authors: Abdel‐Khalik Ayman S. , Massoud Ahmed , Ahmed Shehab
Published: February 2019

In electric drive applications that are based on high‐speed induction motors (IMs) with an extended speed range, stator winding pole‐changing is a possible technique to avoid oversizing the driving motor. The electronic pole changing employed in multiphase IMs has gained recent interest because it avoids physical winding reconfiguration. The effective number of poles of the air gap flux distribution can be electronically altered by simply changing the applied current sequence to a multiphase stator. The main problem associated with this technique is the significant increase in machine magnetising current with the increase in effective pole number when conventional multiphase distributed windings are employed. This study proposes a new fractional‐slot concentrated winding layout with a special stator connection suitable for pole‐amplitude modulated IMs that offers a 2:1 pole ratio while maintaining equal magnetising current for both winding pole pairs. Moreover, constant power operation can be achieved for a speed range of over 4 pu. The main concept is discussed and verified through simulations and experimentally. The machine mathematical model and the required vector space decomposition‐based controller are also presented.
Vehicle classification approach based on the combined texture and shape features with a compressive DL
Authors: Sun Wei , Zhang Xiaorui , Shi Shunshun , He Xiaozheng
Published: February 2019

Automatic vehicle classification is a fundamental task in intelligent transportation systems. Image‐based vehicle classification is challenging due to occlusion, low‐illumination, and scale change. This study proposes an innovative approach by combining texture and shape features into a complementary feature and using the complementary feature to train a compressive dictionary to improve accuracy and efficiency. In the feature combination, the scale‐invariant feature transform descriptor is applied to extract the texture and shape features from the original vehicle images and their edge images, respectively. In the dictionary training, a compressive dictionary learning (DL) algorithm, called compressive K singular value decomposition (CKSVD) algorithm, is proposed to improve the dictionary training efficiency. The CKSVD algorithm divides the feature dictionary into several same‐sized data blocks and then performs the DL in each data block based on a very sparse random projection matrix. On the feature combination and DL, the proposed approach employs the kernel sparse representation method to classify vehicles into four types: buses, trucks, vans, and sedans. The kernel sparse representation method enables the linearly inseparable classification in the combined feature space to be linearly separable. Experimental results show that the proposed approach can improve the accuracy and efficiency of vehicle classification.
Improved criticality analysis method of equipment failures in wind turbines
Authors: Ma Zhiyong , Wang Dameng , Teng Wei , Liu Yibing
Published: February 2019

High failure rate and maintenance cost of wind turbines are one of the key issues in wind energy. In view of this, reliability centred maintenance (RCM) has been introduced to distinctively treat equipment failures according to their criticality. Criticality analysis (CA) is a pivotal step of RCM, derived from the failure frequency and failure modes effects of equipment, which determines when and how to maintain the wind turbines. However, in traditional CA, failure data is roughly considered, e.g. failure frequency is categorised as different ranks instead of accurate numerical value. In addition, the method of calculating criticality by multiplying variables is sensitive to variable ranges and values, which is unable to distinctly distinguish the contributions of different variables. Aimed at these deficiencies, an improved CA method with expansibility is proposed to assess the criticality of equipment failures in wind turbines based on Euclidean distance of failure vectors. To assess disparities among criticality ranks from diverse CA methods, an inverse number based method is presented. Several existing CA methods and the proposed CA in this study are compared using the data of wind turbines in literature, and the results verify the effectiveness of the proposed method.
Time‐domain low‐frequency non‐periodic transient EMI measurement system
Authors: Meng Jin , Zhang Xiangming , Zhang Lei , Zhao Zhihua
Published: February 2019

In this study, a time‐domain low‐frequency non‐periodic transient electromagnetic interference (EMI) measurement system is presented. By the use of an antenna, an anti‐aliasing filter, and a digital oscilloscope, the radiated emissions measurement specified by electromagnetic compatibility standard MIL‐STD‐461 is achieved. In the first stage, the antenna receives the radiated emissions of the device under test and the time domain output voltage is acquired in the oscilloscope. Then, to fulfil the spectrum measurement as accurate as an EMI receiver, a spectrum calculating methodology is carried out. Optimised inverse fast Fourier transform procedure for spectrum estimation in the proposed methodology is implemented to reduce the calculation efforts. The proposed EMI measurement technique required only a single time‐domain acquisition and no repeatedly continuous scanning was imposed on the frequency measurement of the EMI test receivers. Due to this benefit, scan times are decreased by several orders of magnitude in comparison with a traditional EMI receiver.
Design and application of condition monitoring for power transmission and transformation equipment based on smart grid dispatching control system
Authors: Zhou Gui‐Ping , Luo Huan‐Huan , Ge Wei‐Chun , Ma Yi‐Ling , Qiu Shi , Fu Li‐Na
Published: February 2019

With the increasing demand for power supply reliability and the transmission equipment is an important part of power generation, transmission and distribution engineering. In the study, which makes use of the advantages and the mechanism of responsibility area of D5000 system platform, in combination with other related applications, the system architecture, software architecture, and related main functions are designed for on‐line monitoring application, and realised the comprehensive analysis of the on‐line monitoring and collecting data of the transmission and transformation equipment, to obtain the characteristic parameters of the reaction state of the equipment, equipment fault diagnosis, analysis and judge the running state of the equipment, to fill the domestic electrical equipment condition monitoring and analysis system of electrical equipment and States unified data processing, analysis and judgment of technology gaps. The active maintenance system based on multi‐dimension data analysis and fault prediction is formed from the state of equipment and referring to the running history of equipment state.
Accommodation capability assessment of high‐voltage direct current with a large‐scale wind power integration system based on risk constraints of sub‐synchronous oscillation
Authors: Xiaoyu Zhan , Chao Liu
Published: February 2019

In order to research the new sub‐synchronous oscillation (SSO) phenomenon caused by the wind power, first, this work studied the characteristics of the wind turbine in the frequency of the SSO, considering the characteristics of the wind controller simultaneously, and established the wind turbine and the power grid transmission model under the SSO propagation path. Then, the non‐infinite equivalent model of the grid power model was proposed in order to change the strengthening degree. Third, a comprehensive evaluation index based on the oscillation energy was presented, and the capacity of the wind power from the frequency limit of the SSO was evaluated; meanwhile, the constraints of the SSO have been studied to maintain the stability of the power network. Finally, the rationality and effectiveness of the method were verified based on the IEEE 39‐node model.
Chitosan–heparin functionalised magnetic nanoparticles for the magnetic recovery of Aspergillus niger lipase enzyme
Authors: Pérez‐Guzmán Ana Karina , Ilyina Anna , Zugasti‐Cruz Alejandro , García‐García Jose Daniel , Segura‐Ceniceros Elda Patricia , Martínez‐Hernández Jose Luis , Ramos‐González Rodolfo
Published: February 2019

This work focuses on the obtention of magnetic nanoparticles functionalised with heparin (MNPH) and their interaction with Aspergillus niger lipase enzyme. The MNPH were obtained by the coprecipitation method, its characterisation was carried out by Fourier transform infrared spectroscopy, X‐ray diffraction, and alternating gradient magnetometry. Functionalisation with heparin was carried out by ultrasound at various times, later the absorption of the enzyme was carried out with two temperatures 4 and 25°C at different concentrations of lipase. For the recovery of the enzyme, a Plackett–Burman design was used, which indicates that the recovered lipase maintains its enzymatic activity when the ionic strength is lower, it was characterised by sodium dodecyl sulphate‐page with which it is demonstrated that it is possible to recover the lipase enzyme through the designed nanostructured system.
Antibody‐functionalised gold nanoparticles‐based impedimetric immunosensor: detection methods for better sensitivity
Authors: Bohli Nadra , Belkilani Meryem , Mora Laurence , Abdelghani Adnane
Published: February 2019

Electrochemical immunosensors are generally layer‐by‐layer or sandwich systems designed to detect an analyte in a solution. Immunosensors are mainly based on the high affinity and specificity of the antibody towards its antigen. This work aims to answer the following question: if we ‘flip’ the immunosensor and build it backwards, thus detecting the antibody with the antigen instead of detecting the antigen with the antibody, will we obtain the same immunosensors properties or not? To answer this question, they tested a system composed of glycated human serum albumin and antibody‐functionalised gold nanoparticles. Impedance spectrum results showed a difference in both the sensitivity and linear range of the built impedimetric immunosensors. The sensitivity of the sensor using the antibody as a bioreceptor was approximated to 0.32 [%. [% (Glycated to total albumin])] − 1] against a sensitivity of 0.80 [%. [% (Glycated to total albumin])] − 1] for the ‘upside‐down’ sensor, using the antigen as a bioreceptor. This study observed also a shift to high glycation levels in the linear range of the upside‐down sensor. These differences could be explained by the effect of steric hindrance and a higher degree of freedom allowing better characteristics for the upside‐down immunosensor.
Gamma rays from red giant wind bubbles entering the jets of elliptical host blazars
Authors: Torres-Albà Núria , Bosch-Ramon Valentí
Published: February 2019

Context. Blazars in elliptical hosts have a population of red giants surrounding their jet. These stars can carry large wind-blown bubbles into the jets, leading to gamma-ray emission through bubble-jet interactions.

Aims. We study the interaction dynamics and the gamma-ray emission produced when the bubbles formed by red giant winds penetrate the jet of a blazar in an elliptical galaxy.

Methods. First, we characterized the masses and penetration rates of the red giant wind bubbles that enter the jet. Then, the dynamical evolution of these bubbles under the jet impact was analysed analytically and numerically, and the radiation losses of the particles accelerated in the interaction were characterised. Finally, the synchrotron and the inverse Compton contributions above ∼100 MeV were estimated under different jet magnetic fields, powers, and Lorentz factors.

Results. We find that an analytical dynamical model is a reasonable approximation for the red giant wind bubble-jet interaction. The radiation produced by these wind bubbles interacting with a jet can have a duty cycle of up to ∼1. For realistic magnetic fields, gamma rays could be detectable from sources within the local universe, preferentially from those with high Lorentz factors (∼10), and this could be a relatively common phenomenon for these sources. For magnetic fields in equipartition with the jet power, and high acceleration rates, synchrotron gamma rays may be detectable even for modest Lorentz factors (∼3), but with a much lower duty cycle.

Conclusions. Blazars in elliptical galaxies within the local universe can produce detectable transient or persistent gamma-ray emission from red giant wind bubbles entering their jets.
Linear and circular polarization of a 1D relativistic jet model
Authors: Mościbrodzka M.
Published: February 2019

Context. Polarimetric observations of black holes allow us to probe structures of magnetic fields and plasmas in strong gravity.

Aims. We present a study of the polarimetric properties of a synchrotron spectrum emitted from a relativistic jet using a low-dimensional model.

Methods. A novel numerical scheme is used to integrate relativistic polarized radiative transfer equations in a slab geometry where the plasma conditions change along the integration path.

Results. We find that the simple model of a non-uniform jet can recover basic observational characteristics of some astrophysical sources with a relativistic jet, such as extremely high rotation measures. Our models incorporate a time-dependent component. A small fluctuation in density or temperature of the plasma along the jet produces significant amounts of fluctuations not only in the fractional linear and circular polarizations, but also in the jet internal rotation measures.

Conclusions. The low-dimensional models presented here are developed within the same computational framework as the complex three-dimensional general relativistic magnetohydrodynamics simulations of black hole disks and jets, and they offer guidance when interpreting the results from more complex polarization models. The models presented here are scalable to stationary and transient polarized radio emissions produced by relativistic plasma ejected from around compact objects, in both stellar-mass and supermassive black hole systems.
Optimal harvesting of a spatially distributed renewable resource with endogenous pricing
Authors: Anita S. , Behringer S. , Mosneagu A.-M. , Upmann T.
Published: February 2019

In this paper, we focus on the exploitation of a renewable resource in a spatial setting. Building upon the spatial harvesting model of [Behringer and Upmann,J. Econ. Dyn. Control42(2014) 105–120], we endogenize the price for the resource assuming that after harvesting the good is non-durable,i.e.the harvesting yield must be supplied on the market instantaneously. We find necessary optimality conditions and use them to derive an iterative algorithm to improve at each step the harvesting effort. We find that with endogenous prices the full exploitation result of [Behringer and Upmann,J. Econ. Dyn. Control42(2014) 105–120] may cease to hold.
Analysis of the ECGI inverse problem solution with respect to the measurement boundary size and the distribution of noise
Authors: Addouche Mohammed , Bouarroudj Nadra , Jday Fadhel , Henry Jacques , Zemzemi Nejib
Published: February 2019

In this work, we analyze the influence of adding a body surface missing data on the solution of the electrocardiographic imaging inverse problem. The difficulty comes from the fact that the measured Cauchy data is provided only on a part of the body surface and thus a missing data boundary is adjacent to a measured boundary. In order to construct the electrical potential on the heart surface, we use an optimal control approach where the unknown potential at the external boundary is also part of the control variables. We theoretically compare this case to the case where the Dirichlet boundary condition is given on the full accessible surface. We then compare both cases and based on the distribution of noise in the measurements, we conclude whether or not it is worth to use all the data. We use the method of factorization of elliptic boundary value problems combined with the finite element method. We illustrate the theoretical results by some numerical simulations in a cylindrical domain. We numerically study the effect of the size of the missing data zone on the accuracy of the inverse solution.
A 3D reaction–diffusion system describing calcium dynamics in cardiac cell
Authors: Bendahmane Mostafa , Erraji Elmahdi , Karami Fahd
Published: February 2019

We are interested in modeling the interaction of calcium dynamics in a medium including sarcolemma and sarcoplasmic reticulum. The governing equations consist of a nonlinear reaction–diffusion system representing the various calcium fluxes and theirs buffers in the two media. We address the question of existence of weak solutions by using a fixed-point approach. We propose a finite element method for this system, we establish the existence of the discrete solution, and we show that the discrete solution generated by the given scheme converges to the corresponding weak solution for the model studied. Finally, we give some 2D and 3D numerical examples to our model.
Propensity-Score-Methoden zur Schätzung von Behandlungseffekten: Eine Chance für die rehabilitative Versorgungsforschung
Authors: Fauser David , Bethge Matthias
Published: February 2019

Die randomisierte kontrollierte Studie ist der Goldstandard zur Überprüfung der Wirksamkeit einer Intervention. Sie ermöglicht eine unverzerrte Schätzung des Behandlungseffekts, da die Zuweisung zu den Behandlungsarmen zufällig erfolgt und damit unabhängig von Patientenmerkmalen oder vorangehenden Maßnahmen der Patientenversorgung. Unterschiede im Zielkriterium können kausal auf die Behandlung zurückgeführt werden. In Beobachtungsstudien erfolgt die Zuweisung in Interventions- und Kontrollgruppe nicht zufällig. Die Zuweisung ist vielmehr mit Patientenmerkmalen assoziiert, für die eine Wirkung auf das Zielkriterium nicht ausgeschlossen werden kann. Effektschätzer aus Beobachtungsstudien müssen deshalb als verzerrt gelten. Methodische Ansätze, die den Propensity Score nutzen, berücksichtigen diese Gruppenunterschiede bei der Analyse von Beobachtungsdaten. Der Propensity Score ist die aufgrund beobachteter Variablen bedingte Wahrscheinlichkeit, die Behandlung zu erhalten. Mittels Propensity-Score-Matching können so balancierte Stichproben von behandelten und unbehandelten Personen gebildet werden. Zur Darstellung der Behandlungseffekte können dieselben absoluten Effektmaße genutzt werden wie in randomisierten kontrollierten Studien.
Zervikaler Flexions-Rotations-Test und physiologischer
Bewegungsumfang – Eine Vergleichsstudie mit myogener temporomandibulärer
Funktionsstörung im Vergleich zu gesunden Probanden
Authors: Klittmann Steffen
Published: February 2019

Greenbaum T, Dvir Z, Reiter S et al. Musculoskelet Sci Pract 2017; 27: 7–13. doi:
10.1016/j.msksp.2016.11.010
Gewalt in der Notfallmedizin – gegenwärtiger Stand in Deutschland
Authors: Hofmann Tobias , Hachenberg Thomas
Published: February 2019

Hintergrund In den letzten Jahren werden Mitarbeiter von Rettungsdiensten und Notaufnahmen immer häufiger Opfer von gewalttätigen Übergriffen während ihres Dienstes. Jedoch wird die Erfassung von Häufigkeiten, Arten, Ursachen, Täterprofilen sowie möglichen Lösungsansätzen und Schutzmaßnahmen in Deutschland bisher – im Vergleich zum angloamerikanischen Sprachraum – eher stiefmütterlich behandelt.

Ziel Das Ziel dieser Arbeit war eine weitgehende Erfassung der bisher vorliegenden aktuellen Daten der letzten Jahre, um einen zusammenfassenden Überblick über die Situation in Deutschland geben zu können.

Ergebnisse Es liegen nur sehr wenige Arbeiten aus Deutschland zu diesem Thema vor. Die gefundenen Arbeiten zeigten, dass Gewalt im Rettungsdienst und in der Notaufnahme nicht nur ein Problem im angloamerikanischen Sprachraum ist. Bis zu 90% der Studienteilnehmer einer Befragung von Rettungsdienstmitarbeitern und 75% der teilnehmenden Mitarbeiter aus Notaufnahmen gaben an, in den letzten Monaten vor der Befragung Opfer von verbaler und/oder physischer Gewalt geworden zu sein. Die Mehrheit der Studienteilnehmer (je nach Studie zwischen 60 und 80%) fühlt sich gar nicht bis unzureichend auf aggressives und gewalttätiges Verhalten vorbereitet und wünscht sich professionelle regelmäßige Weiterbildung in Deeskalationstechniken und Selbstverteidigung. Auch die ständige Anwesenheit von Sicherheitsdiensten wurde zur Verminderung gewaltsamer Übergriffe auf Mitarbeiter durch Studienteilnehmer als sinnvoll erachtet. Um konkretere Aussagen treffen zu können, bedarf es weiterer prospektiver Multicenterstudien.
Analysis of energy consumption improvements of a zero-energy building in a humid mountainous area
Authors: Hoseinzadeh Siamak , Hadi Zakeri Mohammad , Shirkhani Atoosa , Chamkha Ali J.
Published: February 2019

The most significant basis for sustainable development, as well as one of the most critical concerns of today's human societies, is energy and how it is consumed. In Iran, about 40% of energy is consumed in residential, commercial, and office buildings. Considering the importance of energy for sustainable development, buildings with zero energy consumption have found a lot of supporters. In the present paper, buildings with zero energy consumption in the north of Iran (Qa'emshahr city) were studied, and the feasibility study for constructing such buildings in this humid mountainous area was done. In this regard, a residential building with a conventional condition was considered as a sample, and energy efficiency parameters were investigated; using different methods, energy consumption of the building was reduced to zero. The research method in this study was based on two principles. At first, using scientific resources, new methods for reducing energy consumption in buildings and how they are managed were researched; in the second step, which is the main part of this paper, using DesignBuilder Software, the energy consumption of the building was determined. In the final step, the power generation capacity and panel area and economic considerations in the payback period were calculated per month. For this purpose, an average of 63 m2 of the solar panel was considered to be the electrical power of the building, which was able to fully produce the building's electricity requirement in 8 months. According to the results, with activities, the amount of electrical energy used for air conditioning in the building has been released by 80% and has been detracted from 34 MW to 7 MW. In the case of return on investment (R0I), to supply the required power generation for the building, it would be possible to receive about 15 000 $per year from the Iranian Ministry of Energy.
Theoretical study of the complexes of dichlorobenzene isomers with argon. II. SAPT analysis of the intermolecular interaction
Authors: Shirkov Leonid , Makarewicz Jan
Published: February 2019

The interaction of argon with dichlorobenzene isomers (DCB-Ar) has been analyzed with the help of the symmetry-adapted perturbation theory based on the density functional description of monomer properties (DFT-SAPT). The global potential energy surface (PES) of these complexes determined from the DFT-SAPT interaction energy (Eint) values has been compared to the CCSD(T) (coupled cluster method including single and double excitations with perturbative triple excitations) PES reported in the companion Paper I [J. Makarewicz and L. Shirkov, J. Chem. Phys. 150, 074301 (2019)]. The equilibrium structures and the binding energies found using DFT-SAPT and CCSD(T) methods combined with adequate basis sets are in good agreement. Besides DCB-Ar, we confirmed that DFT-SAPT gives accurate values of these quantities for other complexes containing an aromatic molecule and Ar. However, DFT-SAPT PES of DCB-Ar is flatter than the corresponding CCSD(T) one. As a result, the intermolecular vibrational energies are systematically underestimated. The analytical form of the important interrelations between SAPT components of Eint, established previously by us [J. Makarewicz and L. Shirkov, J. Chem. Phys. 144, 204115 (2016)], has been approved for the DCB-Ar complexes. Simplified SAPT models based on these relations have been employed to explain physical reasons for differences in the structures and the binding energies of DCB-Ar isomers. It is shown that the equilibrium distance of Ar to DCB plane and the binding energy are determined mainly by dispersion energy. The shift of Ar toward Cl is caused by both exchange and dispersion terms.
Formation and properties of InGaN QDs: Influence of substrates
Authors: Chang A. S. , Walrath J. C. , Frost T. , Greenhill C. , Occena J. , Hazari A. , Bhattacharya P. , Goldman R. S.
Published: February 2019

We examine the formation and properties of InGaN quantum dots (QDs) on free-standing GaN and GaN/sapphire templates, with and without buried InGaN/GaN QD superlattices (SLs). We use scanning tunneling microscopy (STM) and scanning tunneling spectroscopy to image the QDs and measure their electronic states. As the number of layers preceding the QDs increases (i.e., increasing substrate complexity), the total QD density increases. For free-standing GaN, STM reveals a mono-modal QD-size-distribution, consistent with a limited density of substrate threading dislocations serving as heterogeneous nucleation sites. For GaN/sapphire templates, STM reveals a bimodal QD-size-distribution, presumably due to the nucleation of additional ultra-small InN-rich QDs near threading dislocations. For multi-period QD SLs on GaN/sapphire templates, an ultra-high density of QDs, with a mono-modal size distribution is apparent, suggesting that QD nucleation is enhanced by preferential nucleation at strain energy minima directly above buried QDs. We discuss the relative influences of strain fields associated with threading dislocations and buried QD SLs on the formation of InGaN QDs and their effective bandgaps.
Joint reconstruction and prediction\break of random dynamical systems under\break borrowing of strength
Authors: Hatjispyros Spyridon J. , Merkatas Christos
Published: February 2019

We propose a Bayesian nonparametric model based on Markov Chain Monte Carlo methods for the joint reconstruction and prediction of discrete time stochastic dynamical systems based on m-multiple time-series data, perturbed by additive dynamical noise. We introduce the Pairwise Dependent Geometric Stick-Breaking Reconstruction (PD-GSBR) model, which relies on the construction of an m-variate nonparametric prior over the space of densities supported over Rm. We are focusing on the case where at least one of the time-series has a sufficiently large sample size representation for an independent and accurate Geometric Stick-Breaking estimation, as defined in Merkatas et al. [Chaos 27, 063116 (2017)]. Our contention is that whenever the dynamical error processes perturbing the underlying dynamical systems share common characteristics, underrepresented data sets can benefit in terms of model estimation accuracy. The PD-GSBR estimation and prediction procedure is demonstrated specifically in the case of maps with polynomial nonlinearities of an arbitrary degree. Simulations based on synthetic time-series are presented.
Self-collimation and slow-sound effect of spoof surface acoustic waves
Authors: Korozlu N. , Kaya O. A. , Cicek A. , Ulug B.
Published: February 2019

Self-collimated propagation and slow-sound effect of spoof acoustic surface waves over a thin solid slab with partially embedded spherical cavities in a square lattice are numerically and experimentally demonstrated. Band structure calculations via the Finite-Element Method reveal that a single spoof surface wave band appears below the air-line, which flattens as the spheres are embedded deeper, leveraging the observation of self-collimated slow spoof modes. For a radius-to-lattice constant ratio of 0.45 and embedding depth of 60% of the radius, the surface band is such that non-diffractive guiding of spoof waves along the [11] direction can be achieved. Persistent self-collimated propagation of spoof surface waves over long distances is demonstrated through frequency-domain Finite-Element Method simulations. Plane waves incident from air can couple to the self-collimated modes for a wide range of azimuthal angle of incidence up to 60°, where the polar angle of incidence can be in the range of ±15°. Self-collimation of spoof waves is experimentally realized by employing a plane-wave source incident from air. In addition, when the embedding depth is higher than 85%, self-collimated slow spoof modes with group indices higher than 15 can be obtained. The observed phenomena can be utilized in two-dimensional acoustic systems such as logic circuits and interferometric sensing devices.
Influence of external parameters on nonlinear behaviors in a helium dielectric-barrier discharge excited by a modulated voltage
Authors: Li Xuechen , Liu Rui , Gong Dandan , Li Xiaoni , Ren Chenhua , Jia Pengying
Published: February 2019

Using a one-dimensional fluid model, period multiplication and chaos behaviors in the time domain are numerically investigated in atmospheric pressure helium dielectric-barrier discharge excited by a modulated sinusoidal voltage. The results indicate that with the increasing duty ratio of the modulated voltage, various nonlinear behaviors are obtained, including asymmetric single-period, period-three, period-seven, chaotic, and symmetric single-period states. More details are revealed that period-four, period-nine, and period-thirteen states can also be observed between period-three and period-seven states. For the period-three state, there are six current pulses in each current period, which have different amplitudes with each other. Besides the duty ratio, the sinusoidal frequency of the modulated voltage is varied, which results in similar nonlinear behaviors. Additionally, under a duty ratio of 80%, it maintains a stable period-two state with the increasing voltage amplitude or the decreasing gap width. During this process, the pulse number and duration time increase per half voltage cycle. Finally, spatial distributions of the electric field, electron density, and ion density are investigated for the novel period-three state, which is qualitatively explained through analyzing the influence of the averaged density of electrons and metastable states just before the discharge moments.
Laser-induced fluorescence of C2 and C3 in colliding carbon plasma
Authors: Oliver John , Bharadwaj Nikhil , Sizyuk Tatyana
Published: February 2019

The formation of transient molecular species, C2 and C3, was studied in the collision of two laser-produced carbon plasmas using laser-induced fluorescence. In vacuum, two closely neighboring laser-produced plasmas will collide, as they expand into one another or are forced into occupying the same space. This so-called colliding plasma produces a highly collisional composite plasma plume from the two individual plasmas which persists longer with enhanced prevalence of certain plasma processes such as recombination. In an inertial fusion energy (IFE) chamber, successive shots will ablate first wall material (e.g., graphitic carbon). Inwardly collapsing plasma will attain such a colliding plasma state as it converges inwards toward the chamber center. The presented results elucidate the early formation of C2 and C3, precursors to larger carbon structures which may contaminate an IFE chamber.
Exact two-component equation-of-motion coupled-cluster singles and doubles method using atomic mean-field spin-orbit integrals
Authors: Asthana Ayush , Liu Junzi , Cheng Lan
Published: February 2019

A new semi-atomic-orbital- based algorithm for a two-component spin-orbit (SO) equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) method using mean-field SO integrals is reported. The new algorithm removes the major computational bottlenecks of a SO-EOM-CCSD calculation associated with the evaluation, storage, and processing of the H¯ab,cd elements in the similarity-transformed Hamiltonian involving four virtual orbital labels. The partial recovery of spin symmetry in the present algorithm reduces the storage requirement by an order of magnitude and the floating point operation count for the evaluation of the ladder-like term by a factor of three to four. EOM-CCSD calculations of excited states in the triiodide ion (I3−) using the exact two-component Hamiltonian in combination with atomic mean-field SO integrals (X2CAMF) are reported as a validation of the implementation and also as a demonstration of the capability of the new algorithm to correlate extended virtual spaces. X2CAMF-EOM-CCSD calculations of the ground and excited states in As2, Sb2, and Bi2 are also presented and compared with the available experimental studies. An analysis based on the computed spectroscopic constants as well as the compositions of the excited-state wavefunctions strongly supports a new assignment for the lowest 2u and 0u− levels in the photoelectron spectrum of Bi2.
Predicting streamer discharge front splitting by ionization seed profiling
Authors: Zhu Yujie , Zhang Xuewei , He Jinliang
Published: February 2019

There has been extensive research on the branching mechanisms of streamer discharges. A consistent link between theories and experiments, which can enable prediction or even control of streamer front splitting, is to be established. For this, a clearer knowledge of streamer seed profiles needs to be first obtained with the use of specifically designed electrodes and then correlated with the observations of streamer development. In this work, a 2D deterministic model of negative streamers in air with photo-ionization in an overvolted gap is numerically solved with the ionization seeds assumed as the superposition of Gaussians. The “indicative profile approach” developed here can reliably relate the change in a quantitative measure of geometrical irregularity of the seed profiles with specific electron densities to the emergence of front splitting of streamer discharges at various voltages, seed characteristic sizes, and preionization levels. The results could inform experiments to clarify streamer branching mechanisms.
Ion temperature gradient turbulence modification in quasi-axisymmetry
Authors: Lazerson Samuel A. , Xanthopoulos Pavlos , Mynick Harry , Gates David
Published: February 2019

The large flexibility of the proposed QUASAR facility [Gates et al., Nucl. Fusion 57, 126064 (2017)] is leveraged in order to explore the effect of magnetic shear on adiabatic Ion Temperature Gradient (ITG) turbulence. The QUASAR facility is a reimagining of the National Compact Stellarator Experiment utilizing and expanding upon the already constructed coil set. Recent work using fixed boundary optimization of the LI383 equilibrium (upon which QUASAR is based) has suggested possible improvements to ITG turbulence [Mynick et al., Plasma Phys. Controlled Fusion 56, 094001 (2014)]. In this work, a different approach is taken, wherein a series of self-consistent free boundary VMEC equilibria are developed for QUASAR. These equilibria assume temperature and density profiles consistent with 2% beta and ohmic current drive. In each configuration, the toroidal field coils are energized to different values and the STELLOPT code is used to vary the modular coil current and net toroidal current. The edge value of rotational transform is targeted in the optimization, producing a magnetic shear scan. All these configurations share similar neoclassical transport levels, while nonlinear GENE flux tube simulations show up to a factor of four change in adiabatic ITG turbulence at various radii. Comparisons of proxy functions and linear flux tube runs are also made. This work highlights the capability of the QUASAR experiment as a tool to explore transport in 3D magnetic fields and the possibility of the further improvements to stellarators through optimization.