bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Laser Powder Bed Fusion Benchmarking—Initial Trials with Inconel 625
Authors: Wong H. , Dawson K. , Ravi G. A. , Howlett L. , Jones R. O. , Sutcliffe C. J.
Published: November 2019

Production rate is an increasingly important factor in the deployment of metal additive manufacturing (AM) throughout industry. To address the perceived low production rate of metal AM systems based on single-laser powder bed fusion (L-PBF), several companies now offer systems in which melting has been parallelised by the introduction of multiple, independently controlled laser beams. Nevertheless, a full set of studies is yet to be conducted to benchmark the efficiency of multi-laser systems and, at the same time, to verify if the mechanical properties of components are compromised due to the increase in build rate. This study addresses the described technology gaps and presents a 4-beam L-PBF system operating in “single multi” (SM) mode (SM-L-PBF) where each of the four lasers is controlled so that it melts all of a particular components’ layers and produces specimens for comparison with standard L-PBF specimens from the same machine. That is all four lasers making all of some of the parts were compared to a single-laser manufacturing all of the parts. Build parameters were kept constant throughout the manufacturing process and the material used was Inconel 625 (IN625). Stress-relieving heat treatment was conducted on As-built (AB) specimens. Both AB and heat-treated (HT) specimen sets were tested for density, microstructure, tensile strength and hardness. Results indicate that the stress-relieving heat treatment increases specimen ductility without compromising other mechanical properties. SM-L-PBF has achieved a build rate of 14 cm3/h when four 200 W lasers were used to process IN625 at a layer thickness of 30 μm. An increase in the build rate of 2.74 times (build time reduction: 63%) has been demonstrated when compared to that of L-PBF, with little to no compromises in specimen mechanical properties. The observed tensile properties exceed the American Society for Testing Materials (ASTM) requirements for IN625 (by a margin of 22 to 26% in the 0.2% offset yield strength). Average specimen hardness and grain size are in the same order as that reported in literatures. The study has demonstrated that a multi-laser AM system opens up opportunities to tackle the impasse of low build rate in L-PBF in an industrial setting and that at least when operating in single mode there is no detectable degradation in the mechanical and crystallographic characteristics of the components produced.
T1ρ-mapping for assessing knee joint cartilage in children with juvenile idiopathic arthritis — feasibility and repeatability
Authors: Barendregt Anouk M. , Mazzoli Valentina , van den Berg J. Merlijn , Kuijpers Taco W. , Maas Mario , Nederveen Aart J. , Hemke Robert
Published: November 2019

Background

Ongoing arthritis in children with juvenile idiopathic arthritis (JIA) can result in cartilage damage.

Objective

To study the feasibility and repeatability of T1ρ for assessing knee cartilage in JIA and also to describe T1ρ values and study correlation between T1ρ and conventional MRI scores for disease activity.

Materials and methods

Thirteen children with JIA or suspected JIA underwent 3-tesla (T) knee MRI that included conventional sequences and a T1ρ sequence. Segmentation of knee cartilage was carried out on T1ρ images. We used intraclass correlation coefficient to study the repeatability of segmentation in a subset of five children. We used the juvenile arthritis MRI scoring system to discriminate inflamed from non-inflamed knees. The Mann-Whitney U and Spearman correlation compared T1ρ between children with and without arthritis on MRI and correlated T1ρ with the juvenile arthritis MRI score.

Results

All children successfully completed the MRI examination. No images were excluded because of poor quality. Repeatability of T1ρ measurement had an intraclass correlation coefficient (ICC) of 0.99 (P<0.001). We observed no structural cartilage damage and found no differences in T1ρ between children with (n=7) and without (n=6) inflamed knees (37.8 ms vs. 31.7 ms, P=0.20). However, we observed a moderate correlation between T1ρ values and the juvenile arthritis MRI synovitis score (r=0.59, P=0.04).

Conclusion

This pilot study suggests that T1ρ is a feasible and repeatable quantitative imaging technique in children. T1ρ values were associated with the juvenile arthritis MRI synovitis score.
Can´t beat the heat? Importance of cardiac control and coronary perfusion for heat tolerance in rainbow trout
Authors: Ekström Andreas , Gräns Albin , Sandblom Erik
Published: November 2019

Coronary perfusion and cardiac autonomic regulation may benefit myocardial oxygen delivery and thermal performance of the teleost heart, and thus influence whole animal heat tolerance. Yet, no study has examined how coronary perfusion affects cardiac output during warming in vivo. Moreover, while β-adrenergic stimulation could protect cardiac contractility, and cholinergic decrease in heart rate may enhance myocardial oxygen diffusion at critically high temperatures, previous studies in rainbow trout (Oncorhynchus mykiss) using pharmacological antagonists to block cholinergic and β-adrenergic regulation showed contradictory results with regard to cardiac performance and heat tolerance. This could reflect intra-specific differences in the extent to which altered coronary perfusion buffered potential negative effects of the pharmacological blockade. Here, we first tested how cardiac performance and the critical thermal maximum (CTmax) were affected following a coronary ligation. We then assessed how these performances were influenced by pharmacological cholinergic or β-adrenergic blockade, hypothesising that the effects of the pharmacological treatment would be more pronounced in coronary ligated trout compared to trout with intact coronaries. Coronary blockade reduced CTmaxby 1.5 °C, constrained stroke volume and cardiac output across temperatures, led to earlier cardiac failure and was associated with reduced blood oxygen-carrying capacity. Nonetheless, CTmaxand the temperatures for cardiac failure were not affected by autonomic blockade. Collectively, our data show that coronary perfusion improves heat tolerance and cardiac performance in trout, while evidence for beneficial effects of altered cardiac autonomic tone during warming remains inconclusive.
An ensemble based on neural networks with random weights for online data stream regression
Authors: de Almeida Ricardo , Goh Yee Mey , Monfared Radmehr , Steiner Maria Teresinha Arns , West Andrew
Published: November 2019

Most information sources in the current technological world are generating data sequentially and rapidly, in the form of data streams. The evolving nature of processes may often cause changes in data distribution, also known as concept drift, which is difficult to detect and causes loss of accuracy in supervised learning algorithms. As a consequence, online machine learning algorithms that are able to update actively according to possible changes in the data distribution are required. Although many strategies have been developed to tackle this problem, most of them are designed for classification problems. Therefore, in the domain of regression problems, there is a need for the development of accurate algorithms with dynamic updating mechanisms that can operate in a computational time compatible with today’s demanding market. In this article, the authors propose a new bagging ensemble approach based on neural network with random weights for online data stream regression. The proposed method improves the data prediction accuracy as well as minimises the required computational time compared to a recent algorithm for online data stream regression from literature. The experiments are carried out using four synthetic datasets to evaluate the algorithm’s response to concept drift, along with four benchmark datasets from different industries. The results indicate improvement in data prediction accuracy, effectiveness in handling concept drift, and much faster updating times compared to the existing available approach. Additionally, the use of design of experiments as an effective tool for hyperparameter tuning is demonstrated.
A new point-of-care test for the rapid detection of urinary tract infections
Authors: Arienzo Alyexandra , Cellitti Valentina , Ferrante Valeria , Losito Francesca , Stalio Ottavia , Murgia Lorenza , Marino Rossella , Cristofano Flavia , Orrù Michela , Visca Paolo , Di Somma Salvatore , Silvestri Lorena , Ziparo Vincenzo , Antonini Giovanni
Published: November 2019

Urinary tract infections (UTIs) are among the most common infections in all age groups. Fast and accurate diagnosis is essential to ensure a timely and effective therapy. Alongside with reference culture-based methods, several point-of-care tests (POCTs) for early detection of UTIs have been developed, but they have not been significantly implemented in current clinical practice. The Micro Biological Survey (MBS) POCT is a simple test developed by MBS Diagnostics Ltd. (London, UK) for the detection and management of UTIs. The present study has been undertaken to investigate the potentials and limits of the MBS POCT. A total of 349 patients were enrolled in two open-label, monocentric, non-interventional clinical trials in collaboration with an Emergency Medicine department and the outpatient clinic of two hospitals in Rome. Results of urine analysis using the MBS POCT were compared with those of the routine culture-based tests for UTI diagnosis performed by the hospital laboratory. The MBS POCT provided fast results revealing high bacterial count UTIs (≥ 105 CFU/ml) with 97% accuracy, 92% sensitivity, 100% specificity, 99% PPV, and 96% NPV within a 5-h analytical time threshold.
Aggregation mechanisms for crowd predictions
Authors: Palan Stefan , Huber Jürgen , Senninger Larissa
Published: November 2019

When the information of many individuals is pooled, the resulting aggregate often is a good predictor of unknown quantities or facts. This aggregate predictor frequently outperforms the forecasts of experts or even the best individual forecast included in the aggregation process (“wisdom of crowds”). However, an appropriate aggregation mechanism is considered crucial to reaping the benefits of a “wise crowd”. Of the many possible ways to aggregate individual forecasts, we compare (uncensored and censored) arithmetic and geometric mean and median, continuous double auction market prices and sealed bid-offer call market prices in a controlled experiment. We use an asymmetric information structure, where participants know different sub-sets of the total information needed to exactly calculate the asset value to be estimated. We find that prices from continuous double auction markets clearly outperform all alternative approaches for aggregating dispersed information and that information lets only the best-informed participants generate excess returns.
Genetic mapping of leaf-related traits in autotetraploid alfalfa (Medicago sativa L.)
Authors: He Fei , Kang Junmei , Zhang Fan , Long Ruicai , Yu Long-Xi , Wang Zhen , Zhao Zhongxiang , Zhang Tiejun , Yang Qingchuan
Published: November 2019

Understanding the genetic architecture of leaf-related traits is important for improving alfalfa yield. Leaf size has a great influence on the protein content and yield for alfalfa. In this study, a low-yielding precocious alfalfa individual (paternal parent) and a high-yielding late-maturing alfalfa individual (maternal parent) were used to build a hybrid F1 population of 149 individuals. The linkage map was constructed using simple sequence repeat and single nucleotide polymorphism markers, and quantitative trait loci (QTL) for leaf length, leaf width, and leaf area were mapped using 3 years phenotypic data. We identified a total of 60 QTLs associated with leaf size. These QTLs were located on chromosomes 1 to 8, and the percent of phenotypic variation explained by QTL ranged from 2.97% to 18.78%. There were 13 QTLs explain more than 10% of phenotypic variation, most of which represent novel loci controlling leaf traits that have not been found in previous studies. The nearest markers of QTL may be used in marker-assisted selection and breeding alfalfa new varieties with high yield.
Dimensionality and Predictive validity of the Classroom Learning Activities Checklist in Prekindergarten
Authors: Reynolds Arthur J. , Candee Allyson J.
Published: November 2019

The Classroom Learning Activities Checklist (CLAC) is a brief classroom observation measure that assesses task-oriented and self-regulated learning in early childhood environments. We assessed the tool’s dimensionality and validity in predicting prekindergarten (PreK) learning gains. The study sample is from the Midwest Child-Parent Center (MCPC) program, an evidence-based PreK–3rd grade school reform model providing comprehensive educational and family support services. Data from 1358 enrolled students in 72 observed classrooms indicated that a 2-factor model—instructional responsiveness and student engagement—explained 50% of the variance in item scores. Evidence for construct validity was strong. Linear and probit regression analyses indicated that CLAC scores independently predicted learning gains in literacy (ES = .34SD) and math (ES = .30SD) on the Teaching Strategies Gold Assessment System, a standardized performance assessment. Findings support the validity of the CLAC in assessing the classroom learning environment. Implications for program monitoring, evaluation, and professional development are discussed.
Dietary lipids, gut microbiota and lipid metabolism
Authors: Schoeler Marc , Caesar Robert
Published: November 2019

The gut microbiota is a central regulator of host metabolism. The composition and function of the gut microbiota is dynamic and affected by diet properties such as the amount and composition of lipids. Hence, dietary lipids may influence host physiology through interaction with the gut microbiota. Lipids affect the gut microbiota both as substrates for bacterial metabolic processes, and by inhibiting bacterial growth by toxic influence. The gut microbiota has been shown to affect lipid metabolism and lipid levels in blood and tissues, both in mice and humans. Furthermore, diseases linked to dyslipidemia, such as non-alcoholic liver disease and atherosclerosis, are associated with changes in gut microbiota profile. The influence of the gut microbiota on host lipid metabolism may be mediated through metabolites produced by the gut microbiota such as short-chain fatty acids, secondary bile acids and trimethylamine and by pro-inflammatory bacterially derived factors such as lipopolysaccharide. Here we will review the association between gut microbiota, dietary lipids and lipid metabolism
Mutual funds, tunneling and firm performance: evidence from China
Authors: Chizema Amon , Jiang Wei , Kuo Jing-Ming , Song Xiaoqi
Published: November 2019

In contrast to US companies, Chinese firms have concentrated ownership with the effect that the central agency problem emanates from controlling shareholders expropriating minority shareholders, a phenomenon referred to as ‘tunneling’. This study examines the monitoring effect of mutual funds on the tunneling behavior of controlling shareholders. Due to the distinctive institutional settings in China, including a high level of ownership concentration, underdeveloped legal system in the stock markets and weak governance mechanisms in the mutual fund industry, we find that an increase in mutual fund ownership effectively mitigates the tunneling behavior of controlling shareholders thus improving firm performance. Nonetheless, after the mutual fund ownership reaches a certain threshold, an increase in concentrated mutual fund ownership is associated with heavier tunneling and lower firm performance. This may suggest that concentrated mutual funds collude with controlling shareholders in order to preserve their private interests. Moreover, the above effects are found to be more pronounced for firms with heavier tunneling activities. Our finding of the non-monotonic monitoring role of mutual funds brings attention to the private interest theory for mutual funds, an aspect that has been largely ignored in previous studies on mutual funds.
Early career performance and its correlation with gender and publication output during doctoral education
Authors: Lindahl Jonas , Colliander Cristian , Danell Rickard
Published: November 2019

Publishing in peer-reviewed journals as a part of the doctoral education is common practice in many countries. The publication output of doctoral students is increasingly used in selection processes for funding and employment in their early careers. Against the backdrop of this development, the aim of this study is to examine (1) how performance during the doctoral education affect the probability of attaining research excellence in the early career; and (2) if there is performance differences between males and females in the early career and to which degree these gender differences can be explained by performance differences during the doctoral education. The data consist of Swedish doctoral students employed at the faculty of science and technology and the faculty of medicine at a Swedish university. Our main conclusions are that (1) research performance during the doctoral education has a positive effect on attaining excellence in the early career; (2) there is an interaction between publication volume and excellence during doctoral education suggesting that a combination of quantity and quality in doctoral students’ performance is indicative of future excellence; (3) there are performance differences in the early career indicating that males have a higher probability of attaining excellence than females, and; (4) this difference is partly explained by performance differences during the doctoral education.
Approaching or Re-thinking the Realm of Criminal Law?
Authors: Lacey Nicola
Published: November 2019

In his latest monograph, The Realm of Criminal Law, Antony Duff gives us a further, magisterial statement of the vision of criminal law, its procedural framework, and its sanctioning system, which he has been developing over the past 35 years. This is Duff’s own book-length contribution to the tremendously fruitful collaborative Criminalization project. That project has already generated four edited volumes (Duff et al. in The boundaries of the criminal law, 2010; The structures of the criminal law, 2011; The constitution of the criminal law, 2013; Criminalization: the political morality of the criminal law, 2014) and two fine monographs by Farmer (Making the modern criminal law: criminalization and civil order, 2016) and Tadros (Wrongs and crimes, 2016; see also Tadros in The ends of harm: the moral foundations of criminal law, 2011). It will shape the field for decades to come; and it has decisively laid to rest a longstanding puzzle about why, within criminal law theory, the principles underlying criminalisation had received relatively little attention as compared with those underlying, most obviously, criminal responsibility (cf. Lacey in Frontiers of criminality, 1995).
Human scent samples for chemical analysis
Authors: Pojmanová Petra , Ladislavová Nikola , Škeříková Veronika , Kania Patrik , Urban Štěpán
Published: November 2019

This study is focused on finding an optimal preparation of the human scent samples for their detailed chemical analysis in connection with the possible forensic identifications of human individuals in the future. At the present time, the scent identification of people is carried out nearly exclusively using specially trained dogs. It is assumed that the human scent contains a certain group of compounds which allows the identification of people, the so-called human scent signature; however, its chemical composition is completely unknown, as of now. The principal problem of human scent studies consists in the very low concentrations of thousands of the scent compounds, whereas their relative concentrations are usually dramatically different. It seems to be obvious that the most appropriate analytical technique for these thousands of different chemical compounds is GC/MS. However, it is also necessary to find the most suitable sorbent material for human scent collection, an extraction solvent, and a pre-concentration technique. The selection of the appropriate gas chromatographic method is also important to achieve the optimal resolution of the targeted compounds. Of course, in the first instance, it is necessary to decide what it means “the most suitable” for human scent chemical analysis.
Blanking induced damage in thin 3.2% silicon steel sheets
Authors: Ghadbeigi H. , Al-Rubaye A. , Robinson F. C. J. , Hawezy D. , Birosca S. , Atallah K.
Published: November 2019

The cores of electrical motors and transformers are made by blanking, piercing and stacking of thin metallic sheets having various features cut from the original blank. The material experiences local plastic deformation near the cut edge due to the blanking operation. The quality and efficiency of the produced products are directly affected by the mechanical and magnetic properties of the blanks at the cut edge. The effects of the blanking process on deformation evolution in thin sheets of high Si electrical steels was investigated. In-situ blanking experiments together with the digital image correlation (DIC) technique were used to quantify local deformation evolution during thin sheet blanking operations. Magnetic hysteresis losses were measured using a purpose-built single sheet tester and linked to the measured deformation maps. The residual stresses were qualitatively assessed by means of nano-hardness measurements while the local microstructural properties and dislocation generations were determined using EBSD analysis of the blanked parts. The results indicated that for the tested materials with 0.1t blanking clearance, electrical steel sheets with 0.2 mm thickness experiences larger deformation prior to fracture during blanking compared with samples having 0.35 mm thickness. This has a direct relationship with the measured hysteresis losses. However, the dislocation maps indicated that dislocations of GNDs are more pronounced for thicker samples that aligns with the effect of dislocations on magnetic power losses rather than hysteresis losses measured in this research.
Mathematics and Theology in the Thought of Nicholas of Cusa
Authors: Murawski Roman
Published: November 2019

Nicholas of Cusa was first of all a theologian but he was interested also in mathematic and natural sciences. In fact philosophico-theological and mathematical ideas were intertwined by him, theological and philosophical ideas influenced his mathematical considerations, in particular when he considered philosophical problems connected with mathematics and vice versa, mathematical ideas and examples were used by him to explain some ideas from theology. In this paper we attempt to indicate this mutual influence. We shall concentrate on the following problems: (1) the role and place of mathematics and mathematical knowledge in knowledge in general and in particular in theological knowledge, (2) ontology of mathematical objects and their origin, in particular their relations to God and their meaning for the description of the world and physical reality, (3) infinity in mathematics versus infinity in theology and their mutual relations and connections. It will be shown that—according to Nicholas—mathematics and mathematical thinking are tools of rationalization of theology and liberating it in a certain sense from the trap of apophatic theology.
Flow structure and rock-breaking feature of the self-rotating nozzle for radial jet drilling
Authors: Liao Hua-Lin , Jia Xia , Niu Ji-Lei , Shi Yu-Cai , Gu Hong-Chen , Xu Jun-Fu
Published: November 2019

For improving the hole-enlarging capability, roundness and rock-breaking efficiency of the nozzle in radial jet drilling, a new structure of self-rotating nozzle was put forward. The flow structure and rock-breaking features of the self-rotating nozzle were investigated with sliding mesh model and labortary tests and also compared with the straight and the swirling integrated nozzle and multi-orifice nozzle which have been applied in radial jet drilling. The results show that the self-rotating jet is energy concentrated, has longer effective distance, better hole-enlarging capability and roundness and impacts larger circular area at the bottom of the drilling hole, compared with the other two nozzles. Forward jet flow generated from the nozzle is peak shaped, and the jet velocity attenuates slowly at the outer edge. Due to periodic rotary percussion, the pressure fluctuates periodically on rock surface, improving shear and tensile failures on the rock matrix and thereby enhancing rock-breaking efficiency. The numerical simulation results of the flow structure of the nozzle are consistent with the experiments. This study provides an innovative approach for radial jet drilling technology in the petroleum industry.
Multi-objective optimization of high-sulfur natural gas purification plant
Authors: Shang Jian-Feng , Ji Zhong-Li , Qiu Min , Ma Li-Min
Published: November 2019

There exists large space to save energy of high-sulfur natural gas purification process. The multi-objective optimization problem has been investigated to effectively reduce the total comprehensive energy consumption and further improve the production rate of purified gas. A steady-state simulation model of high-sulfur natural gas purification process has been set up by using ProMax. Seven key operating parameters of the purification process have been determined based on the analysis of comprehensive energy consumption distribution. To solve the problem that the process model does not converge in some conditions, back-propagation (BP) neural network has been applied to substitute the simulation model to predict the relative parameters in the optimization model. The uniform design method and the table U21 (107) have been applied to design the experiment points for training and testing BP model. High prediction accuracy can be achieved by using the BP model. Non-dominated sorting genetic algorithm-II has been developed to optimize the two objectives, and 100 Pareto optimal solutions have been obtained. Three optimal points have been selected and evaluated further. The results demonstrate that the total comprehensive energy consumption is reduced by 13.4% and the production rate of purified gas is improved by 0.2% under the optimized operating conditions.
Factors regulating the coastal nutrient filter in the Baltic Sea
Authors: Carstensen Jacob , Conley Daniel J. , Almroth-Rosell Elin , Asmala Eero , Bonsdorff Erik , Fleming-Lehtinen Vivi , Gustafsson Bo G. , Gustafsson Camilla , Heiskanen Anna-Stiina , Janas Urzsula , Norkko Alf , Slomp Caroline , Villnäs Anna , Voss Maren , Zilius Mindaugas
Published: November 2019

The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different biogeochemical processes altering nutrient and organic matter fluxes on the passage from land to sea. This review investigates the most important processes for removal of nutrients and organic matter, and the factors that regulate the efficiency of the coastal filter. Nitrogen removal through denitrification is high in lagoons receiving large inputs of nitrate and organic matter. Phosphorus burial is high in archipelagos with substantial sedimentation, but the stability of different burial forms varies across the Baltic Sea. Organic matter processes are tightly linked to the nitrogen and phosphorus cycles. Moreover, these processes are strongly modulated depending on composition of vegetation and fauna. Managing coastal ecosystems to improve the effectiveness of the coastal filter can reduce eutrophication in the open Baltic Sea.
Cash for trash: an agro-economic value assessment of urban organic materials used as fertilizers in Cameroon
Authors: Thuriès Laurent J.-M. , Ganry Francis , Sotamenou Joel , Oliver Robert , Parrot Laurent , Simon Serge , Montange Denis , Fernandes Paula
Published: November 2019

The rapid expansion of cities in sub-Saharan Africa generates increasing volumes of diversified organic wastes that require management and a high population need for local and fresh vegetables. Linking the different sources of organic materials generated in these cities with the needs of local food producers for fertilizers prepared from recycled organic materials is challenging. This requires that producers obtain the results they expect from the organic materials they recycle. Thus, recycling these organic materials in their raw form or after composting presents an opportunity for periurban agriculture, although the great variability in the quantity and quality of these materials raises questions about the consistency between their agronomic value and their economic value. In two large cities of Cameroon (Yaoundé and Bafoussam), different types of organic materials were sampled: unprocessed livestock waste and composts from manure or municipal solid waste. From an agronomic perspective, we calculated the fertilization value based on the nutrient (nitrogen, phosphorus, and potassium) content of the organic materials. From an economic perspective, we calculated the value based on the nutrient content of the organic materials and their substitution unit prices and recorded the current market price. This is the first time that this combined approach has been used in sub-Saharan Africa. Our results showed considerable variability and discrepancy in both the agronomic and the economic values. The market prices overvalued the urban composts by a factor of 6, while chicken feces were undervalued by a factor of 3. The unprocessed organic materials were the most interesting from an economic and agronomic perspective. Our findings suggest that (i) the composting process needs to be improved and (ii) the humus potential should be calculated to better assess the amendment value of organic materials and as a basis for adjusting their market price.
Distributed control system architecture for balancing and stabilizing traffic in the network of multiple autonomous intersections using feedback consensus and route assignment method
Authors: Wuthishuwong Chairit , Traechtler Ansgar
Published: November 2019

Autonomous and intelligent system show a remarkable step in urban traffic management. Autonomous Intersection Management (AIM) is an outstanding example of using an autonomous vehicle and wireless communication technology. The traffic performance of a single AIM system has been proved in many works however, traffic in the network of multiple AIMs is waiting for an implementation. Coordination of traffic between intersections in the network is an important step of managing the overall networked traffic throughput. The authors modeled the traffic network with the multi-agents concept and used the discrete consensus algorithm to coordinate between autonomous agents and implemented the rerouting algorithm in order to distribute the excessive traffics to neighbored intersections with the optimal condition. Our target is to have a balance traffic in each intersection and reaches the equilibrium where the stability has been not compromised. The results show that reaching consensus condition will bring the networked traffic to an equilibrium state where a peak traffic will not be happened. In addition, this method shows that when traffic in a network reached consensus, it will also converge to the Nash equilibrium in the finite time.
Testing effects of loss framing and checklists: evidence from a field experiment on wellness program participation in Philadelphia
Authors: Bhanot Syon P. , Roberto Christina A. , Chainani Anjali , Williamson Charles , den Braven Mehra
Published: November 2019

Loss framing and checklist formatting are two oft-cited tools for encouraging behavior change, but there is little causal evidence on their impact in field settings. We partnered with the City of Philadelphia to test the effectiveness of these tools to increase completion of the City’s wellness program. In our experiment, 5235 City employees and retirees were randomly assigned to receive one of four postcard versions (using a 2 × 2 design), whereby we varied both framing (gain or loss) and how instructions were provided (information only or information in checklist format). Our results suggest that neither loss framing nor the checklist formatting significantly influenced the likelihood that individuals would complete the wellness tasks, or how quickly they completed the tasks. We conclude that this specific form of employee behavior may be difficult to influence through the “passive” behavioral interventions we tested, and suggest that a more “active” approach may be required in such instances.
Investigating the Effects of tDCS on Visual Orientation Discrimination Task Performance: “the Possible Influence of Placebo”
Authors: Bin Dawood A. , Dickinson A. , Aytemur A. , Howarth C. , Milne E. , Jones M.
Published: November 2019

The non-invasive neuromodulation technique tDCS offers the promise of a low-cost tool for both research and clinical applications in psychology, psychiatry, and neuroscience. However, findings regarding its efficacy are often equivocal. A key issue is that the clinical and cognitive applications studied are often complex and thus effects of tDCS are difficult to predict given its known effects on the basic underlying neurophysiology, namely alterations in cortical inhibition-excitation balance. As such, it may be beneficial to assess the effects of tDCS in tasks whose performance has a clear link to cortical inhibition-excitation balance such as the visual orientation discrimination task (ODT). In prior studies in our laboratory, no practice effects were found during 2 consecutive runs of the ODT, thus in the current investigation, to examine the effects of tDCS, subjects received 10 min of 2 mA occipital tDCS (sham, anode, cathode) between a first and second run of ODT. Surprisingly, subjects’ performance significantly improved in the second run of ODT compared to the first one regardless of the tDCS stimulation type they received (anodal, cathodal, or sham-tDCS). Possible causes for such an improvement could have been due to either a generic “placebo” effect of tDCS (as all subjects received some form of tDCS) or an increased delay period between the two runs of ODT of the current study compared to our previous work (10-min duration required to administer tDCS as opposed to ~ 2 min in previous studies as a “break”). As such, we tested these two possibilities with a subsequent experiment in which subjects received 2-min or 10-min delay between the 2 runs (with no tDCS) or 10 min of sham-tDCS. Only sham-tDCS resulted in improved performance thus these data add to a growing literature suggesting that tDCS has powerful placebo effect that may occur even in the absence of active cortical modulation.
Estimating Unknown Cycles in Geophysical Data
Authors: Shi Xueheng , Gallagher Colin
Published: November 2019

Examples of cyclic (periodic) behavior in geophysical data abound. In many cases the primary period is known, such as in daily measurements of rain, temperature, and sea level. However, many time series of measurements contain cycles of unknown or varying length. We consider the problem of estimating the unknown period in a time series. We review the basic methods, compare their performance through a simulation study using observed sea level data, apply them to an astronomical data set, and discuss generalizations of the methods.
Analysis of Ocean Tide‐Induced Magnetic Fields Derived From Oceanic In Situ Observations: Climate Trends and the Remarkable Sensitivity of Shelf Regions
Authors: Petereit Johannes , Saynisch‐Wagner Jan , Irrgang Christopher , Thomas Maik
Published: November 2019

Tidal motion of oceanic salt water through the ambient geomagnetic field induces periodic electromagnetic field signals. Amplitudes of the induced signals are sensitive to variations in electrical seawater conductivity and, consequently, to changes in oceanic temperature and salinity. In this paper, we computed and analyzed time series of global ocean tide‐induced magnetic field amplitudes. For this purpose, we combined data of global in situ observations of oceanic temperature and salinity fields from 1990–2016 with data of oceanic tidal flow, the geomagnetic field, mantle conductivity, and sediment conductance to derive ocean tide‐induced magnetic field amplitudes. The results were used to compare present day developments in the oceanic climate with two existing climate model scenarios, namely, global oceanic warming and Greenland glacial melting. Model fits of linear and quadratic long‐term trends of the derived magnetic field amplitudes show indications for both scenarios. Also, we find that magnetic field amplitude anomalies caused by oceanic seasonal variability and oceanic climate variations are 10 times larger in shallow ocean regions than in the open ocean. Consequently, changes in the oceanic and therefore the Earth's climate system will be observed first in shelf regions. In other words, climate variations of ocean tide‐induced magnetic field amplitudes are best observed in shallow ocean regions using targeted monitoring techniques.
Strain Rate‐Dependent Hardening‐Softening Characteristics of Gas Hydrate‐Bearing Sediments
Authors: Deusner C. , Gupta S. , Xie X.‐G. , Leung Y. F. , Uchida S. , Kossel E. , Haeckel M.
Published: November 2019

The presence of gas hydrates (GHs) increases the stiffness and strength of marine sediments. In elasto‐plastic constitutive models, it is common to consider GH saturation (Sh) as key internal variable for defining the contribution of GHs to composite soil mechanical behavior. However, the stress‐strain behavior of GH‐bearing sediments (GHBS) also depends on the microscale distribution of GH and on GH‐sediment fabrics. A thorough analysis of GHBS is difficult, because there is no unique relation between Sh and GH morphology. To improve the understanding of stress‐strain behavior of GHBS in terms of established soil models, this study summarizes results from triaxial compression tests with different Sh, pore fluids, effective confining stresses, and strain histories. Our data indicate that the mechanical behavior of GHBS strongly depends on Sh and GH morphology, and also on the strain‐induced alteration of GH‐sediment fabrics. Hardening‐softening characteristics of GHBS are strain rate‐dependent, which suggests that GH‐sediment fabrics dynamically rearrange during plastic yielding events. We hypothesize that rearrangement of GH‐sediment fabrics, through viscous deformation or transient dissociation and reformation of GHs, results in kinematic hardening, suppressed softening, and secondary strength recovery, which could potentially mitigate or counteract large‐strain failure events. For constitutive modeling approaches, we suggest that strain rate‐dependent micromechanical effects from alterations of the GH‐sediment fabrics can be lumped into a nonconstant residual friction parameter. We propose simple empirical evolution functions for the mechanical properties and calibrate the model parameters against the experimental data.
Solar Wind Interaction With Jupiter's Magnetosphere: A Statistical Study of Galileo In Situ Data and Modeled Upstream Solar Wind Conditions
Authors: Vogt Marissa F. , Gyalay Szilard , Kronberg Elena A. , Bunce Emma J. , Kurth William S. , Zieger Bertalan , Tao Chihiro
Published: November 2019

Jupiter's magnetosphere is often said to be rotationally driven, with strong centrifugal stresses due to large spatial scales and a rapid planetary rotation period. While the solar wind is therefore expected to have a relatively small influence on Jupiter's magnetosphere and aurora, there is considerable observational evidence that the solar wind does affect the magnetopause standoff distance, auroral radio emissions, and the ultraviolet auroral position and brightness. We report on the results of a comprehensive, quantitative study of the influence of the solar wind dynamic pressure on magnetospheric data sets measured by the Galileo mission (1996–2003). Using model predictions of the solar wind conditions near Jupiter calculated by propagating measurements made near the Earth, we have established how predicted changes in the solar wind affect the magnitude and direction of the magnetic field in the magnetosphere, the hectometric auroral radio emissions, and energetic particles in Jupiter's magnetosphere. We find that increases in the solar wind dynamic pressure are statistically associated with magnetospheric compression events but that tail reconnection and plasmoid release is most likely driven internally by the Vasyliunas cycle. We find no link between solar wind conditions and the occurrence of quasiperiodic modulations in the magnetosphere. Overall, we conclude that activity in Jupiter's magnetosphere is both internally and solar wind driven. Finally, we examine the effects of solar wind‐induced magnetospheric compressions on Jupiter's auroral brightness and mapping, finding that a solar wind compression could shift the auroral mapping of a given point in the magnetosphere by ~3° on average.
Pump Power Effects on Second Harmonic Stimulated Electromagnetic Emissions During Ionosphere Heating
Authors: Yellu A. D. , Scales W. A. , Mahmoudian A. , Bernhardt P. A. , Siefring C. L. , Briczinski S. , Nossa E. , McCarrick M. J.
Published: November 2019

Due to the potential for new diagnostic capabilities, there has been renewed interest in the generation of ionospheric stimulated electromagnetic emissions (SEEs) near the second harmonic of the pump frequency (ω0), a process known as second harmonic generation (SHG). Observations of SHG during experiments at the High Frequency Active Auroral Research Program facility in which ω0 was stepped near the third harmonic of the electron gyrofrequency, 3ωce, and the transmit power linearly increased over the heating cycle at each ω0, were reported recently. A key observation was the linkage between SEEs within ±30 Hz of ω0, due to stimulated Brillouin scatter, and within ±30 Hz of 2ω0. This current work reports further High Frequency Active Auroral Research Program observations that compare the time evolution of SEEs including SHG under the following two transmit power conditions (I) linear power ramp (II) maximum available power (2.8 MW). During these experiments, ω0 was stepped near 3ωce and also 2ωce. The results show that SEEs within ±100 Hz of ω0 and 2ω0 are both suppressed within a few seconds when the ionosphere is irradiated with the maximum available power. These SEEs appear to be suppressed before the onset of field‐aligned irregularities at the upper hybrid layer which is not in line with previous reports. Thus, other mechanisms, which are discussed, could possibly be responsible for the observed suppression of stimulated Brillouin scatter and SHG. Some preliminary diagnostics are derived from the SHG spectra temporal evolution by leveraging concepts from the field of laser plasma interactions.
MELISSA: System description and spectral features of pre‐ and post‐midnight F‐region echoes
Authors: Rodrigues Fabiano S. , Zhan Weijia , Milla Marco A. , Fejer Bela G. , de Paula Eurico R. , Neto Acacio C. , Santos Angela M. , Batista Inez S.
Published: November 2019

Most of the low‐latitude ionospheric radar observations in South America come from the Jicamarca Radio Observatory, located in the western longitude sector (∼75°W). The deployment of the 30 MHz FAPESP‐Clemson‐INPE (FCI) coherent backscatter radar in the magnetic equatorial site of São Luis, Brazil, in 2001 allowed observations to be made in the eastern sector (∼45°W). However, despite being operational for several years (2001–2012), FCI only made observations during daytime and pre‐midnight hours, with a few exceptions. Here, we describe an upgraded system that replaced the FCI radar and present results of full‐night F‐region observations. This radar is referred to as Measurements of Equatorial and Low‐latitude Ionospheric irregularities over São Luís, South America (MELISSA), and made observations between March 2014 and December 2018. We present results of our analyses of pre‐ and post‐midnight F‐region echoes with focus on the spectral features of post‐midnight echoes and how they compare to spectra of echoes observed in the post‐sunset sector. The radar observations indicate that post‐midnight F‐region irregularities were generated locally and were not a result of “fossil” structures generated much earlier in time (in other longitude sectors) and that drifted into the radar field‐of‐view. This also includes cases where the echoes are weak and that would be associated with decaying equatorial spread F (ESF) structures. Collocated digisonde observations show modest but noticeable F‐region apparent uplifts prior to post‐midnight ESF events. We associate the equatorial uplifts with disturbed dynamo effects and with destabilizing F‐region conditions leading to ESF development.
Magma Oscillations in a Conduit‐Reservoir System, Application to Very Long Period (VLP) Seismicity at Basaltic Volcanoes: 1. Theory
Authors: Liang Chao , Karlstrom Leif , Dunham Eric M.
Published: November 2019

Very long period (VLP, 2–100 s) seismic signals at basaltic volcanoes like Kilauea, Hawai‘i, and Mount Erebus, Antarctica are likely from resonant oscillations of magma within the shallow plumbing system. The system consists of conduits connected to cracks (dikes and sills) or reservoirs of other shapes. A quantitative understanding of wave propagation and resonance in a coupled conduit‐crack system is required to interpret observations. In this work, we idealize the system as an axisymmetric conduit coupled to a tabular crack, accounting for fluid inertia, compressibility, and viscosity, buoyancy, and crack wall elasticity. We perform time domain simulations and eigenmode analyses of the governing equations, linearized about a rest state. The fundamental mode or conduit‐reservoir mode reflects the balance of conduit magma inertia with buoyancy (and, for small cracks, crack wall elasticity). Magma oscillates in an effectively incompressible manner within the conduit, deflating and inflating the crack, which couples to the surrounding solid to produce observable surface displacements. For sufficiently low viscosity magmas, viscous effects are confined to boundary layers. Shorter period modes are primarily reverberating crack waves with negligible coupling to the conduit. Finally, we introduce an approximate reduced model for the conduit‐reservoir mode, which can also handle more general reservoir geometries (e.g., spherical chambers). The reduced model connects the observable VLP period and quality factor to two uniquely constrained parameters: the inviscid oscillation period T0 and the viscous diffusion time τvis across the conduit radius. Our models can be extended to study the seismic response of more complex magmatic systems.