bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance and Emissions of Drop-In Aviation Biofuels in a Lab-Scale Gas Turbine Combustor
Authors: Feser Joseph , Gupta Ashwani
Published: August 2020

There is a growing need for drop-in biofuels for gas turbines for enhanced energy security and sustainability. Several fuels are currently being developed and tested to reduce dependency on fossil fuels while maintaining performance, particularly in the aviation industry. The transition from traditional fossil fuels to sustainable biofuels is much desired for reducing the rapidly rising CO2 levels in the environment. This requires biofuels to be drop-in ready, where there are no adverse effects on performance and emissions upon replacement. In this study, the performance and emissions of four different aviation drop-in biofuels were evaluated. They include UOP HEFA-SPK, Gevo ATJ, Amyris Farnesane, and SB-JP-8. These aviation biofuels are currently being produced and tested to be ready for full or partial drop-in fuels as the replacement of traditional jet fuels. The characteristic performance of each fuel from the prevaporized liquid fuels was performed in a high-intensity (20 MW/m3-atm) reverse flow combustor. The NO emissions showed near unity ppm levels for each of the fuels examined with a minimum at an equivalence ratio of ∼0.6, while CO levels were in the range of 1000–1300 ppm depending on the fuel at an equivalence ratio between 0.75 and 0.8. For an equivalence ratio range between 0.4 and 0.6, NO and CO emissions remained very low (between 1–2 ppm NO and 2400–2900 ppm CO) depending on the fuel. The examined biofuels did not show any instability over a wide range of equivalence ratios from lean to near stoichiometric condition. These results provide promising results on the behavior of these drop-in aviation biofuels for use in high-intensity gas turbine combustors providing stability and cleaner performance without any modification to the combustor design.
Improved Exergy Evaluation of Ammonia-Water Absorption Refrigeration System Using Inverse Method
Authors: Singh Adityabir , Das Ranjan
Published: August 2020

In this study, the compatibility of exergy destruction minimization (EDM) as the main objective is checked by plotting coefficient of performance (COP), exergy coefficient of performance (ECOP), and overall exergy destruction rate by simultaneously varying input operating temperatures for a 28 TR cooling load absorption system. The component-wise variation in exergy destruction is also considered and it is found that the maxima of COP and ECOP, and the minima of overall exergy destruction lies on a common point, and when the variation of operating temperatures is further extended, the exergy destruction in one of the component becomes negative, which marks the upper bound of the present analysis. At highest valid generator temperature (155 °C), the minimum possible overall exergy destruction rate is 53.50 kW and maximum COP is 0.523. Through inverse optimization (IO) using dragonfly algorithm (DA), the same overall exergy destruction rate is achieved for a wide range of generator temperatures much below than 155 °C, and as low as 127.34 °C. The above variation is explained in terms of flow ratio, mass flowrate of steam, and mass flowrate of cooling water.
An Experimental Study on Segmented-Encapsulated Electrode Dielectric-Barrier-Discharge Plasma Actuator for Mapping Ice Formation on a Surface: A Conceptual Analysis
Authors: Rodrigues F. , Abdollahzadeh M. , Pascoa J. C. , Oliveira P. J.
Published: August 2020

A novel design of the dielectric barrier discharge (DBD) actuator/sensor is proposed for mapping the location of icing on a surface. The new design uses segmentation of the embedded electrode of the DBD actuator. Segmented DBD actuator/sensor devices were fabricated and experimentally tested in terms of mechanical, thermal and sensing abilities. The sensing capability of the new actuator was analyzed experimentally. Stationary and dynamic icing tests were conducted and the electrical characteristics of the DBD were measured. A parametric study on the effect of the electrode dimensions on the degree of sensitivity of the device was performed. Experimental results show that by using a segmented configuration it is possible to sense the onset of ice formation and also to detect its location. Furthermore, it is possible to detect the initiation of the melting process and measure the time for the water/ice to be completely expelled from the surface. It is also shown that the segmented actuator has better deicing performance in comparison to the conventional actuators. It is also shown that the thermal and active flow control abilities are not compromised by the segmented configuration and thus this device may perform deicing, ice formation and location detection and active flow control.
Creative Design of Legged Mobile Landers With Multi-Loop Chains Based on Truss-Mechanism Transformation Method
Authors: Lin Rongfu , Guo Weizhong
Published: August 2020

This paper proposes a novel family of the legged mobile lander (LML) with multi-loop chains to enable the stationary lander to walk, which is helpful to the Return and Base construction missions in the planetary exploration project. Generally, there are many issues that need to be focused, but one of the key issues is during the landing phase, for which the lander needs to be designed as a truss with ability to bear a large impact, while during the walking phase, the lander needs to be designed as a mechanism with flexible walking ability. To resolve this issue, a novel method for designing a mechanism based on a truss, which also can be called as the truss-mechanism transformation (TMT) method is developed. First, the detailed concept of the same topological arrangements (TAs) of a truss and a mechanism is proposed. Two singularity positions for the truss-mechanism transform are introduced. Second, following the concept, the procedure for designing a mechanism based on the TMT method is presented. Third, some basic knowledge for the creative design of the mechanism is introduced, including the intersection rules of motion characteristics, motion characteristic relationship of multi-loop mechanisms, and so on. Fourth, according to the procedure of the TMT method, numerous novel structures of LMLs with multi-loop chains are obtained. Finally, after the type qualitative evaluation, one typical LML is selected as an example to show its functions among stowed, walking, and orientation positions.
Optimizing Piezoelectric Material Location and Size for Multiple-Mode Vibration Reduction of Turbomachinery Blades
Authors: Kelley Christopher R. , Lopp Garrett K. , Kauffman Jeffrey L.
Published: August 2020

Modern turbomachinery blades have extremely low inherent damping, which can lead to high transient vibrations and failure through high-cycle fatigue. Smart materials enable vibration reduction while meeting strict blade requirements such as weight and aerodynamic efficiency. In particular, piezoelectric-based vibration reduction offers the potential to reduce vibration semi-actively while simultaneously harvesting sufficient energy to power the implementation. The placement and the size of the piezoelectric material is critical to the vibration reduction capabilities of the system. Furthermore, the implementation should target multiple vibration modes. This study develops a procedure to optimize electromechanical coupling across multiple vibration modes for a representative turbomachinery blade with surface-mounted piezoelectric patches. Experimental validation demonstrates good coupling across three targeted modes with a single piezoelectric patch. Placing the piezoelectric material in regions of high signed strain energy for all targeted modes enables vibration reduction across all of the targeted modes.
Gas Flow in Microchannels and Nanochannels With Variable Cross Section for All Knudsen and All Mach Number Values
Authors: Milićev Snežana S. , Stevanović Nevena D.
Published: August 2020

The analytical solution for steady viscous pressure-driven compressible isothermal gas flow through micro- and nanochannels with variable cross section for all Knudsen and all Mach number values is presented in this paper. The continuum one-dimensional governing equations are solved using the friction factor that is established in a special way to provide solutions for mass flow rate, pressure, and velocity distribution through the microchannels and nanochannels in the entire rarefaction regime. The friction factor, defined by the general boundary condition and generalized diffusion coefficient proposed by Beskok and Karniadakis (1999, “A Model for Flows in Channels, Pipes, and Ducts at Micro and Nano Scales,” J. Microscale Thermophys. Eng., 3, pp. 43–77), spreads the solution application to all rarefaction regimes from continuum to free molecular flow. The correlation between the product of friction factor and Reynolds number (Poiseuille number) and Knudsen number is established explicitly in the paper. Moreover, the obtained solution includes the inertia effect, which allows the application of the solution to both subsonic and supersonic gas flows, which was not shown earlier. The presented solution confirms the existence of the Knudsen minimum in the diverging, converging, and microchannels and nanochannels with constant cross section. The proposed solution is verified by comparison with experimental, analytical, and numerical results available in literature.
Sex Differences in Lower Limb Proprioception and Mechanical Function Among Healthy Adults
Authors: Hu Xiaoyue , Li Jingxian , Wang Lin
Published: August 2020

Twenty-four healthy adults, including 12 females and 12 males, participated in the study. Each female participant completed three trials in three different phases of one menstrual cycle, which included follicular, ovulatory, and luteal phases. The study aimed to investigate whether there is any difference in joint kinetic sense, neuromuscular coordination, and isokinetic muscle strength (a) between healthy males and females at different phases of the menstrual cycle and (b) between females at different phases of the menstrual cycle. The outcome measures included the number of jumps in the square-hop test and ankle and knee proprioception, which were assessed by an electric-driven movable frame rotated at 0.4 deg/s and isokinetic muscle strength measured by a computerized dynamometer (Biodex). For the square-hop test (p = .006), ankle dorsiflexion/plantar flexion (p < .05), knee flexion/extension (p < .05), the relative peak torque of the isokinetic muscle strength at the 60° and 180° knee flexion/extension (p < .001), and the 30° and 120° ankle plantar flexion/dorsiflexion (p < .05) between females and males showed significant differences. For the females at different phases of the menstrual cycle, significant differences were found on ankle dorsiflexion (p = .003), plantar flexion (p = .023), knee extension (p = .029), the square-hop test (p = .036), and relative peak torque of isokinetic muscle strength at 180° knee flexion (p = .029). This study demonstrated that there are sex differences in lower limb proprioception and mechanical function. Females at ovulatory and luteal phases have better lower limb proprioception than at the follicular phase.
Twenty years of International Council of Ophthalmology fellowships: description of the programme and the impact on more than 1100 awardees
Authors: Torres-Netto Emilio A , Gabel-Obermaier Cordula , Gabel Peter , Gloor Balder , Wiedemann Peter , Taylor Hugh , Davey Clare , Quilter Nicola , Seitz Berthold
Published: August 2020

Background/Aims

The International Council of Ophthalmology (ICO) offers fellowship programmes to help young ophthalmologists, mainly from low-resource countries, improve their practical or research skills in ophthalmology subspecialty areas. Using questionnaires, the objective of the present study was to evaluate how the ICO Fellowship Programme has impacted on improving knowledge, skills and the careers of young ophthalmologists from low-resource countries.

Methods

From 2001 to 2019 overall 1140 ICO fellowships were awarded. A questionnaire was sent to ICO fellows after the conclusion of their fellowship and another 3 years later. Part 1 contained 26 questions, while Part 2 had 21 questions. The answers were collected through an online platform and analysed descriptively thereafter.

Results

1101 Part 1 questionnaires had been sent to former fellows, with a return rate of 47% (516 responses) and 829 Part 2 questionnaires with a return rate of 47% (390 responses). Overall, 98.3% strongly or somewhat agreed that knowledge in their subspecialty has improved considerably. Whereas only 19% of them held a lecturer, senior lecturer or head of subspecialty department position prior to the fellowship, 46% of them held such a position 3 years after the fellowship was completed.

Conclusions

The ICO Fellowship Programmes aim to promote the enhancement of eye care delivery and eye health in low-resource countries, the professional development of young leaders and the improvement of eye care. The results of the current study confirm the expectation of such a positive impact. Moreover, almost half of the responding participants have been appointed to a local leadership position in their home country.
Characterisation of thickness changes in the peripapillary retinal nerve fibre layer in patients with Leber’s hereditary optic neuropathy
Authors: Wang Dan , Liu Hong-Li , Du Yang-Yang , Yuan Jiajia , Li Xin , Tian Zhen , Zhou Haiqiang , Wang Shuang , Song Lin , Sun Jian , Xiao Xiao , Wang Zhi-Tao , Li Bin
Published: August 2020

Background

Limited studies have identified the changes in peripapillary retinal nerve fibre layer (pRNFL) thickness in patients with chronic Leber’s hereditary optic neuropathy (LHON) at different stages of the disease. We aimed to characterise the pRNFL thickness changes in patients with LHON having m.11778G>A (MT-ND4) mutation.

Methods

This retrospective cross-sectional study included 221 eyes from patients with LHON (n=145)—classified into seven groups according to disease duration—and 52 eyes from healthy controls (n=26). All subjects underwent pRNFL examinations. pRNFL thickness of the superior, nasal and inferior, and temporal quadrants, and the 360° average were measured.

Results

Within 3 months of onset, the temporal pRNFL thickness decreased significantly, whereas the remaining quadrants and the average pRNFL thickness initially increased. The temporal quadrant (p<0.01) and average pRNFL thickness (p=0.02) significantly decreased at 3–6 months. Excluding that in the nasal quadrant (p=0.93), pRNFL thickness significantly decreased in all other quadrants at 6–9 months. At 9–12 months, the average and individual quadrant pRNFL thicknesses continued to decrease. Compared with 12–24 months, the pRNFL thickness was thinner at 24–60 months and >60 months.

Conclusions

The papillomacular bundle was affected first and preferentially in LHON. pRNFL thickness initially increased and then decreased, corresponding to the retinal ganglion cell swelling and apoptosis. pRNFL thinning first occurred in the temporal quadrant, followed by the inferior and superior quadrants, and finally, the nasal quadrant. pRNFL continued to thin slowly in some quadrants even after 60 months.
Protocol for a cluster-randomised non-inferiority trial of one versus two doses of ivermectin for the control of scabies using a mass drug administration strategy (the RISE study)
Authors: Lake Susanna J , Phelan Sophie L , Engelman Daniel , Sokana Oliver , Nasi Titus , Boara Dickson , Gorae Christina , Schuster Tibor , Grobler Anneke C , Osti Millicent H , Andrews Ross , Marks Michael , Whitfeld Margot J , Romani Lucia , Kaldor John , Steer Andrew
Published: August 2020

Introduction

Scabies is a significant contributor to global morbidity, affecting approximately 200 million people at any time. Scabies is endemic in many resource-limited tropical settings. Bacterial skin infection (impetigo) frequently complicates scabies infestation in these settings. Community-wide ivermectin-based mass drug administration (MDA) is an effective control strategy for scabies in island settings, with a single round of MDA reducing population prevalence by around 90%. However, current two-dose regimens present a number of barriers to programmatic MDA implementation. We designed the Regimens of Ivermectin for Scabies Elimination (RISE) trial to investigate whether one-dose MDA may be as effective as two-dose MDA in controlling scabies in high-prevalence settings.

Methods and analysis

RISE is a cluster-randomised non-inferiority trial. The study will be conducted in 20 isolated villages in Western Province of Solomon Islands where population prevalence of scabies is approximately 20%. Villages will be randomly allocated to receive either one dose or two doses of ivermectin-based MDA in a 1:1 ratio. The primary objective of the study is to determine if ivermectin-based MDA with one dose is as effective as MDA with two doses in reducing the prevalence of scabies after 12 months. Secondary objectives include the effect of ivermectin-based MDA on impetigo prevalence after 12 and 24 months, the prevalence of scabies at 24 months after the intervention, the impact on presentation to health facilities with scabies and impetigo, and the safety of one-dose and two-dose MDA.

Ethics and dissemination

This trial has been approved by the ethics review committees of the Solomon Islands and the Royal Children's Hospital, Australia. Results will be disseminated in peer-reviewed publications and in meetings with the Solomon Islands Ministry of Health and Medical Services and participating communities.

Trial registration details

Australian New Zealand Clinical Trials Registry: ACTRN12618001086257. Date registered: 28 June 2018.
Clinical evolution, management and outcomes of patients with COVID-19 admitted at Tygerberg Hospital, Cape Town, South Africa: a research protocol
Authors: Allwood Brian W , Koegelenberg Coenraad FN , Irusen Elvis , Lalla Usha , Davids Razeen , Chothia Yazied , Davids Ryan , Prozesky Hans , Taljaard Jantjie , Parker Arifa , Decloedt Eric , Jordan Portia , Lahri Sa'ad , Moosa Rafique , Schrueder Neshaad , Du Toit Riette , Viljoen Abraham , English Rene , Ayele Birhanu , Nyasulu Peter
Published: August 2020

Introduction

The outbreak of the SARS-CoV-2 virus causing COVID-19, declared a global pandemic by the WHO, is a novel infection with a high rate of morbidity and mortality. In South Africa, 55 421 cases have been confirmed as of 10 June 2020, with most cases in the Western Cape Province. Coronavirus leaves us in a position of uncertainty regarding the best clinical approach to successfully manage the expected high number of severely ill patients with COVID-19. This presents a unique opportunity to gather data to inform best practices in clinical approach and public health interventions to control COVID-19 locally. Furthermore, this pandemic challenges our resolve due to the high burden of HIV and tuberculosis (TB) in our country as data are scarce. This study endeavours to determine the clinical presentation, severity and prognosis of patients with COVID-19 admitted to our hospital.

Methods and analysis

The study will use multiple approaches taking into account the evolving nature of the COVID-19 pandemic. Prospective observational design to describe specific patterns of risk predictors of poor outcomes among patients with severe COVID-19 admitted to Tygerberg Hospital. Data will be collected from medical records of patients with severe COVID-19 admitted at Tygerberg Hospital. Using the Cox proportional hazards model, we will investigate the association between the survival time of patients with COVID-19 in relation to one or more of the predictor variables including HIV and TB.

Ethics and dissemination

The research team obtained ethical approval from the Health Research Ethics Committee of the Faculty of Medicine and Health Sciences, Stellenbosch University and Research Committee of the Tygerberg Hospital. All procedures for the ethical conduct of scientific investigation will be adhered to by the research team. The findings will be disseminated in clinical seminars, scientific forums and conferences targeting clinical care providers and policy-makers.
Secondhand smoke in public places in Vietnam: An assessment 5 years after implementation of the tobacco control law
Authors: Tran Long K , Morawska Lidia , Gartner Coral E , Huong Le T T , Le Hong H T C , Thai Phong K
Published: August 2020

Objectives

This study quantified the secondhand smoke (SHS) concentration in a sample of public places in Vietnam to determine changes in SHS levels 5 years after a public smoking ban was implemented.

Methods

Two monitoring campaigns, one in 2013 (before the tobacco control law was implemented) and another in 2018 (5 years after the implementation of the law) were conducted in around 30 restaurants, cafeterias and coffee shops in major cities of Vietnam. Concentrations of PM2.5, as an indicator of SHS, were measured by portable particulate matter monitors (TSI SidePak AM510 and Air Visual Pro).

Results

The geometric mean PM2.5 concentration of all monitored venues was 87.7 µg/m3 (83.7–91.9) in the first campaign and 55.2 µg/m3 (53.7–56.7) in the second campaign. Pairwise comparison showed the PM2.5 concentrations in the smoking observed area was triple and double those in the non-smoking area and the outdoor environment. After adjusting for sampling locations and times, the SHS concentration 5 years after the implementation of the tobacco control law reduced roughly 45%.

Conclusion

The study results indicate an improvement in air quality in public places in Vietnam via both the reduction in PM2.5 levels and the number of people observed smoking. However, greater enforcement of the free-smoke legislation is needed to eliminate SHS in public places in Vietnam.
A note of the first law of thermodynamics by gravitational decoupling
Authors: Estrada Milko , Prado Reginaldo
Published: August 2020

We provide a way of decoupling the first law of thermodynamics in two sectors : the standard first law of thermodynamics and the quasi first law of thermodynamics. It is showed that both sectors share the same thermodynamics volume and the same entropy. However, the total thermodynamics pressure, the total temperature and the total local energy correspond to a simple sum of the thermodynamics contributions of each sector. On the other hand, turning on the coupling constant $$\alpha $$α, the total energy, given by the Noether charge, increases proportionally to this constant. Furthermore, it is showed a simple example, where, there is a phase transition between stable/unstable black hole, and, due to the application of the decoupling, it is possible to determinate that the cause of this phase transition is the behavior of the temperature at the quasi sector.
Evolution of confined quantum scalar fields in curved spacetime. Part I
Authors: Barbado Luis C. , Báez-Camargo Ana L. , Fuentes Ivette
Published: August 2020

We develop a method for computing the Bogoliubov transformation experienced by a confined quantum scalar field in a globally hyperbolic spacetime, due to the changes in the geometry and/or the confining boundaries. The method constructs a basis of modes of the field associated to each Cauchy hypersurface, by means of an eigenvalue problem posed in the hypersurface. The Bogoliubov transformation between bases associated to different times can be computed through a differential equation, which coefficients have simple expressions in terms of the solutions to the eigenvalue problem. This transformation can be interpreted physically when it connects two regions of the spacetime where the metric is static. Conceptually, the method is a generalisation of Parker’s early work on cosmological particle creation. It proves especially useful in the regime of small perturbations, where it allows one to easily make quantitative predictions on the amplitude of the resonances of the field, providing an important tool in the growing research area of confined quantum fields in table-top experiments. We give examples within the perturbative regime (gravitational waves) and the non-perturbative regime (cosmological particle creation). This is the first of two articles introducing the method, dedicated to spacetimes without boundaries or which boundaries remain static in some synchronous gauge.
Type-II neutrino seesaw mechanism extension of NMSSM from SUSY breaking mechanisms
Authors: Li Zhuang , Wang Fei
Published: August 2020

We propose to accommodate economically the type-II neutrino seesaw mechanism in (G)NMSSM from GMSB and AMSB, respectively. The heavy triplets within neutrino seesaw mechanism are identified to be the messengers. Therefore, the$$\mu $$μ-problem, the neutrino mass generation, LFV as well the soft SUSY breaking parameters can be economically combined in a non-trivial way. General features of such extensions are discussed. The type-II neutrino seesaw-specific interactions can give additional Yukawa deflection contributions to the soft SUSY breaking parameters of NMSSM, which are indispensable to realize successful EWSB and accommodate the 125 GeV Higgs. Relevant numerical results, including the constraints of dark matter and possible LFV processes$$l_i\rightarrow l_j \gamma $$li→ljγetc, are also given. We find that our economical type-II neutrino seesaw mechanism extension of NMSSM from AMSB or GMSB can lead to realistic low energy NMSSM spectrum, both admitting the 125 GeV Higgs as the lightest CP-even scalar. The possibility of the 125 GeV Higgs being the next-to-lightest CP-even scalar in GMSB-type scenario is ruled out by the constraints from EWSB, collider and precision measurements. The possibility of the 125 GeV Higgs being the next-to-lightest CP-even scalar in AMSB-type scenario is ruled out by dark matter direct detection experiments. Possible constraints from LFV processes$$l_i\rightarrow l_j \gamma $$li→ljγcan give an upper bound for the messenger scale.
Enriching feature engineering for short text samples by language time series analysis
Authors: Tang Yichen , Blincoe Kelly , Kempa-Liehr Andreas W.
Published: August 2020

In this case study, we are extending feature engineering approaches for short text samples by integrating techniques which have been introduced in the context of time series classification and signal processing. The general idea of the presented feature engineering approach is to tokenize the text samples under consideration and map each token to a number, which measures a specific property of the token. Consequently, each text sample becomes a language time series, which is generated from consecutively emitted tokens, and time is represented by the position of the respective token within the text sample. The resulting language time series can be characterised by collections of established time series feature extraction algorithms from time series analysis and signal processing. This approach maps each text sample (irrespective of its original length) to 3970 stylometric features, which can be analysed with standard statistical learning methodologies. The proposed feature engineering technique for short text data is applied to two different corpora: the Federalist Papers data set and the Spooky Books data set. We demonstrate that the extracted language time series features can be successfully combined with standard machine learning approaches for natural language processing and have the potential to improve the classification performance. Furthermore, the suggested feature engineering approach can be used for visualizing differences and commonalities of stylometric features. The presented framework models the systematic feature engineering based on approaches from time series classification and develops a statistical testing methodology for multi-classification problems.
Linear Complexity of Binary Threshold Sequences Derived from Generalized Polynomial Quotient with Prime-Power Modulus
Authors: Wang Lianhua , Du Xiaoni
Published: August 2020

In this paper, firstly we extend the polynomial quotient modulo an odd prime [Formula: see text] to its general case with modulo [Formula: see text] and [Formula: see text]. From the new quotient proposed, we define a class of [Formula: see text]-periodic binary threshold sequences. Then combining the Legendre symbol and Euler quotient modulo [Formula: see text] together, with the condition of [Formula: see text], we present exact values of the linear complexity for [Formula: see text], and all the possible values of the linear complexity for [Formula: see text]. The linear complexity is very close to the period and is of desired value for cryptographic purpose. Our results extend the linear complexity results of the corresponding [Formula: see text]-periodic binary sequences in earlier work.
Spiking Neural P Systems with Astrocytes Producing Calcium
Authors: Aman Bogdan , Ciobanu Gabriel
Published: August 2020

The astrocytes are cells which play an essential role in the functioning and interaction of neurons by feeding the respective neurons with calcium ions. Drawing inspiration from this two-way relationship in which the astrocytes influence and are influenced by the neurons by means of calcium ions, in this paper, we define and study spiking neural P systems with astrocytes producing calcium. Distinct from the usual firing rules in spiking neural P systems, the firing condition not only depends on the spikes collected in a neuron but also on the calcium units received from astrocytes. From the perspective of topological structure, the new variant is shown as a directed graph in which synapses link either astrocytes or neurons, as well as astrocytes to neurons and conversely. The computational power of spiking neural P systems with astrocytes producing calcium is investigated; it is proved that these systems using a limited number of rules are Turing universal as both number generating and number accepting devices. It is also presented how to obtain normal forms by removing forgetting rules and delays while preserving the computational power.
Multi-dimensional Prediction Model for Cell Traffic in City Scale
Authors: Wang Hong , Wang Liqun , Zhao Shufang , Yue Xiuming
Published: August 2020

Traffic prediction is a classical time series prediction which has been investigated in different domains, but most existing models are proposed based on limited time or spatial scale. Mobile cellular network traffic prediction is of paramount importance for quality-of-service (QoS) and power management of the cellular base stations, especially in the 5G era. Through the statistical analysis of the real historical traffic data obtained in a city scale spanning across multiple months, this paper makes an in-depth study of the temporal characteristics and behavior rules of the model data traffic. Considering that the time series data show different changing rules under the different time dimensions, spatial dimensions and independent dimensions, a multi-dimensional recurrent neural network (MDRNN) prediction model is established to predict the future cell traffic volume over various temporal and spatial dimensions. The data of this paper are trained and tested over real data of a city, and the granularity of the proposed prediction model can be drilled down to the cell level. Compared with the traditional trend fitting method, the proposed model achieves mean absolute percentage error (MAPE) reduction of 6.56%, and provides guidance for energy efficiency optimization and power consumption reduction of base stations in various temporal and spatial dimensions.
Falling Detection Research Based on Elderly Behavior Infrared Video Image Contours Ellipse Fitting
Authors: Cao Xianghong , Zhang Hua
Published: August 2020

Throughout the world, the proportion of the elders in the total population is increasing dramatically, and home-based care has become the most important form of old-age care. Falling is the most common cause of accidents among the elders at home that poses a huge threat to their health and lives. In order to protect the privacy of the elders an accidental falling detection algorithm for the elders in the home has been proposed in this paper. First, contour-based infrared motion video images are used instead of high-definition cameras to collect the elderly behaviors to protect their privacy. Second, ellipse fitting is performed on the infrared video images of the five behaviors including standing, sitting, squatting, bending and falling. The five geometric characteristic variables of the contour-fitting ellipses including the number of ellipses, centroid positions, ellipsoidal areas, horizontal inclinations and long-short axis ratios of the images, have been extracted. Next, an LSTM model is established using the above variables as inputs for feature extraction and classification. Finally, infrared video images of different types of active behaviors of the elders aged from 50 to 70 years have been selected as IFD database for classification detection. Sixty percent of the IFD images are used as training datasets, and 40% of the IFD images are used as test datasets, and compared with the classification detection of URFD datasets which contains optical RGB HD video images of the different behaviors. The experimental results show the effectiveness of the algorithm proposed in this paper which combines the contour ellipse fitting of the infrared video images and the LSTM feature extraction. The average correct classification rate of the normal and falling down behaviors of the elders is above 95%, which is comparable to the optical RGB datasets. The precision of behavior recognition can effectively protect the privacy of the elders, and provide protection for the accidental falling detection of the elders living alone.
Brain Tumor Segmentation Using 3D Generative Adversarial Networks
Authors: Li Yitong , Chen Yue , Shi Y.
Published: August 2020

Brain tumors have high morbidity and may lead to highly lethal cancer. In clinics, accurate segmentation of tumors is the means for diagnosis and determination of subsequent treatment options. Due to the irregularity and blurring of tumor boundaries, accurately segmenting the tumor lesions has received extensive attention in medical image analysis. In view of this situation, this paper proposed a brain tumor segmentation method based on generative adversarial networks (GANs). The GAN architecture consists of a densely connected three-dimensional (3D) U-Net used for segmentation and a classification network for discrimination, both of which use 3D convolutions to fuse multi-dimensional context information. The densely connected 3D U-Net model introduces a dense connection to accelerate network convergence, extracting more detailed information. The adversarial training makes the distribution of segmentation results closer to that of labeled data, which enables the network to segment some unexpected small tumor subregions. Alternately, train two networks and finally achieve a highly accurate classification of each voxel. The experiments conducted on BraTS2017 brain tumor MRI dataset show that the proposed method has higher accuracy in brain tumor segmentation.
Thermal Performance Analysis of Heat Pipe Intercooler Based on Artificial Neural-Networks
Authors: Zhao Yao , Luo Qingguo , Qiu Mianhao
Published: August 2020

Since the internal heat transfer is a complicated process, the heat pipe heat exchanger of the engine has not been fully understood yet, which is originated from its extreme complexity. In theoretical studies, the involvement of two-phase flow and phase change processes usually simplifies the processing very much, and the model built differs too much from the actual one, resulting in reduced simulation accuracy. In this study, the prediction model of heat transfer and heat resistance of the heat pipe intercooler is established based on artificial neural networks (ANNs). Then the performance of the heat pipe intercooler from heat transfer and heat resistance aspects is investigated. The average relative error between the heat transfer prediction model and the test value is 3.6%, and the average relative error between the resistance prediction model and the test value is 12.68%, which shows that the prediction model can predict the thermal performance of heat pipe intercooler more accurately. Finally, the proposed model is applied to optimize the structural parameters of the heat pipe intercooler, and the optimal parameters are obtained accordingly. These optimal design parameters can provide the basis for further investigation and development of the heat pipe intercooler in diverse applications.
Prediction Method of NOx from Power Station Boilers Based on Neural Network
Authors: Zhang Yuzuo , Li Yuanhao , Zhang Xinyan , Zheng Shijue
Published: August 2020

In the coal-fired power generation system, it is necessary to predict the NOx emissions of power station boilers when it comes to the step to spray ammonia to ensure that NOx emissions do not exceed national standards. Using traditional machine learning algorithms in the modeling of power station boilers will require features selection and steady-state extraction, which is not suitable for practical applications. In order to reduce the NOx prediction error rate under variable operating conditions, a multi-model fusion algorithm S3LX combined with linear regression, XGBoost, and long-short-term memory recurrent neural network is proposed to model the NOx emission prediction of power station boilers. The preprocessing data scheme suitable for power station boiler data sets is proposed and implemented in this paper, which can perform numerical processing, data cleaning and data standardization for boiler’s data and features. A 7-day historical operating data set of a unit in Guangzhou Shajiao C Power Plant was used as the training set and test set and was used to build the NOx emission prediction model after data preprocessing. Results show that compared with traditional machine learning algorithms, S3LX has good prediction ability under varying conditions with an average error of 4.28%. Compared with the average prediction error of the multi-layer perceptron 9.16%, SVM 7.37%, S3LX makes the error significantly reduced and satisfies the actual engineering demand.
On partial skew groupoid rings
Authors: Bagio Dirceu , Paques Antonio , Pinedo Héctor
Published: August 2020

Given a partial action [Formula: see text] of a connected groupoid [Formula: see text] on an associative ring [Formula: see text] we investigate under what conditions the partial skew groupoid ring [Formula: see text] can be realized as a partial skew group ring. In such a case, applications concerning to the separability, semisimplicity and Frobenius property of the ring extension [Formula: see text] as well as to the artinianity of [Formula: see text] are given.
A Note on Berge Equilibria in n-Person 2-Strategy Games
Authors: Sawicki Paweł , Pykacz Jarosław , Bytner Paweł
Published: August 2020

An algorithm for finding all Berge equilibria in the sense of Zhukovskii in n-person 2-strategy games in pure and mixed strategies is given.
Centers of centralizers of nilpotent elements in Lie superalgebras 𝔰𝔩(m|n) or 𝔬𝔰𝔭(m|2n)
Authors: Han Leyu
Published: August 2020

Let [Formula: see text] be the simple algebraic supergroup [Formula: see text] or [Formula: see text] over [Formula: see text]. Let [Formula: see text] and let [Formula: see text], where [Formula: see text] is considered as a superalgebra concentrated in even degree. Suppose [Formula: see text] is nilpotent. We describe the centralizer [Formula: see text] of [Formula: see text] in [Formula: see text] and its center [Formula: see text]. In particular, we give bases for [Formula: see text], [Formula: see text] and [Formula: see text]. We also determine the labeled Dynkin diagram [Formula: see text] with respect to [Formula: see text] and subsequently describe the relation between [Formula: see text] and [Formula: see text].
Coworking-Space Business Models: Micro-Ecosystems and Platforms — Insights from China
Authors: Bouncken Ricarda B. , Qiu Yixin , Clauss Thomas
Published: August 2020

The sharing economy gives rise to numerous new business models. A prominent novel one relates to coworking-spaces, where independent individuals and teams share spaces and amenities and engage in social interaction and information exchange. Yet the business models of such spaces are not well known. Our qualitative study identifies four types of business models design of coworking-spaces in China, where coworking-spaces have sharply increased in number and importance. We find four types of coworking-space business model configurations: efficiency-centered business model, user-centered business model, development-centered business model, and platform-centered business model, which exceed the prior conceptualization of business model themes. Especially, the platform-centered business model relates to innovation policy in China, facilitating mini-spatial innovation ecosystems.
A Refined Speed Limit for the Imaginary-Time Schrödinger Equation
Authors: Sun Jie , Lu Songfeng
Published: August 2020

Recently, Kieu proposed a new class of time-energy uncertainty relations for time-dependent Hamiltonians, which is not only formal but also useful for actually evaluating the speed limit of quantum dynamics. Inspired by this work, Okuyama and Ohzeki obtained a similar speed limit for the imaginary-time Schrödinger equation. In this paper, we refine the latter one to make it be further like that of Kieu formally. As in the work of Kieu, only the initial states and the Hamiltonians, but neither the instantaneous eigenstates nor the full time-dependent wave like functions, which would demand a full solution for a time-dependent system, are required for our optimized speed limit. It turns out to be more helpful for estimating the speed limit of an actual quantum annealing driven by the imaginary-time Schrödinger equation. For certain case, the refined speed limit given here becomes the only useful tool to do this estimation, because the one given by Okuyama and Ohzeki cannot do the same job.
Tackling Architectural Complexity with Modeling
Authors: Montagne Kevin
Published: August 2020

The ever-increasing might of modern computers has made it possible to solve problems once thought too difficult to tackle. Far too often, however, the systems for these functionally complex problem spaces have overly complicated architectures. In this article I use the term
architecture
to refer to the overall macro design of a system rather than the details of how the individual parts are implemented. The system architecture is what is behind the scenes of usable functionality, including internal and external communication mechanisms, component boundaries and coupling, and how the system will make use of any underlying infrastructure (databases, networks, etc.). The architecture is the "right" answer to the question: how does this system work?
Worsening baroreflex sensitivity on progression to type 2 diabetes: localized vs. systemic inflammation and role of antidiabetic therapy
Authors: Bakkar Nour-Mounira Z. , Mougharbil Nahed , Mroueh Ali , Kaplan Abdullah , Eid Ali H. , Fares Souha , Zouein Fouad A. , El-Yazbi Ahmed F.
Published: August 2020

Cardiac autonomic neuropathy (CAN) is an early cardiovascular manifestation of type 2 diabetes (T2D) that constitutes an independent risk factor for cardiovascular mortality and morbidity. Nevertheless, its underlying pathophysiology remains poorly understood. We recently showed that localized perivascular adipose tissue (PVAT) inflammation underlies the incidence of parasympathetic CAN in prediabetes. Here, we extend our investigation to provide a mechanistic framework for the evolution of autonomic impairment as the metabolic insult worsens. Early metabolic dysfunction was induced in rats fed a mild hypercaloric diet. Two low-dose streptozotocin injections were used to evoke a state of late decompensated T2D. Cardiac autonomic function was assessed by invasive measurement of baroreflex sensitivity using the vasoactive method. Progression into T2D was associated with aggravation of CAN to include both sympathetic and parasympathetic arms. Unlike prediabetic rats, T2D rats showed markers of brainstem neuronal injury and inflammation as well as increased serum levels of IL-1β. Experiments on PC12 cells differentiated into sympathetic-like neurons demonstrated that brainstem injury observed in T2D rats resulted from exposure to possible proinflammatory mediators in rat serum rather than a direct effect of the altered metabolic profile. CAN and the associated cardiovascular damage in T2D only responded to combined treatment with insulin to manage hyperglycemia in addition to a nonhypoglycemic dose of metformin or pioglitazone providing an anti-inflammatory effect, coincident with the effect of these combinations on serum IL-1β. Our present results indicate that CAN worsening upon progression to T2D involves brainstem inflammatory changes likely triggered by systemic inflammation.
(Pro)renin receptor decoy peptide PRO20 protects against adriamycin-induced nephropathy by targeting the intrarenal renin-angiotensin system
Authors: Luo Renfei , Yang Kevin , Wang Fei , Xu Chuanming , Yang Tianxin
Published: August 2020

Adriamycin (ADR) administration in susceptible rodents such as the BALB/c mouse strain produces injury to the glomerulus mimicking human chronic kidney disease due to primary focal segmental glomerulosclerosis. The goal of the present study was to use this model to investigate antiproteinuric actions of the (pro)renin receptor decoy inhibitor PRO20. BALB/c mice were pretreated for 1 day with PRO20 at 500 μg·kg−1·day−1 via an osmotic minipump followed by a single injection of vehicle or ADR (10 mg/kg) via the tail vein. Albuminuria and renal function were analyzed at the fourth week post-ADR administration. ADR-treated mice exhibited severe proteinuria, hypoalbuminemia and hyperlipidemia, glomerulosclerosis, podocyte loss, tubulointerstitial fibrosis, and oxidative stress, accompanied by elevated urinary neutrophil gelatinase-associated lipocalin and kidney injury molecule-1, all of which were significantly attenuated by PRO20. Urinary and renal renin activity and angiotensin II were elevated by ADR and suppressed by PRO20. In parallel, urinary and renal H2O2 levels and renal NADPH oxidase 4 (Nox4) and transient receptor potential channel C6 (TRPC6) expression in response to ADR were all similarly suppressed. Taken together, the results of the present study provide the first evidence that PRO20 can protect against podocyte damage and interstitial fibrosis in ADR nephropathy by preventing activation of the intrarenal renin-angiotensin system and upregulation of Nox4 and TRPC6 expression. PRO20 may have a potential application in the treatment of ADR nephropathy.