bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Steam Hammer in the Main Steam System
Authors: Dong Yemin , Wang Cuiyun , Zhao Jiaming , Yu Pei , Zhao Bin
Published: December 2017

The main steam system plays an important role to transfer the saturated steam generated from the steam generator to the main turbine and other steam consumed devices in a pressurized water reactor. During the normal operation, the main steam system transfers the high temperature and pressure steam generated from the steam generator in the nuclear power plant. Once there is an accident situation delivering the main steam isolation valve fast close signal or an unexpected main steam isolation valve close signal, the steam hammer phenomenon will be induced in the main steam system by the main steam isolation valve fast close incident. The steam hammer phenomenon might induce pressure rise rapidly in the main steam system and generate unintended transient load on the main steam system which might have effect on the safety operation of the nuclear power plant. Therefore the steam hammer phenomenon in the main steam system should be studied. The study creates the main steam system model which includes the main steam pipes, devices and connected system based on PIPENET software following the engineering data by a third generation nuclear power plant. The study takes the advantage of the transient mode in PIPENET to simulate the steam hammer phenomenon in the main steam system. The study simulates different boundary conditions and device parameters in order to analyze the different effects on the steam hammer phenomenon in the main steam system. The simulation model could calculate the pressure, load and other parameters in the main steam system during the main steam isolation valve fast close period. The effects of the steam hammer phenomenon could be analyzed through these characteristic parameters. The PIPENET model could simulate the main steam system action during the main system isolation valve fast close incident which helps the study to master the operation and function of the main steam system and verify the integrality of the main steam system in the steam hammer phenomenon. With the simulation and analysis of the steam hammer phenomenon in the main steam system simulated in the PIPENET, the pressure raise which induced by the steam hammer wouldn’t threat the integrality of the main steam system. And the main steam system could ensure the safety operation by steam discharge through the steam dump valves and main steam safety valves.
Study on Corrosion Mechanism of Stellite Hard Alloy Layer of a Main Pump Component
Authors: Wenguang Zhang , Chenggang Yang , Zilong Yi , Chan Li , Chenghao Pu , Yuting Xu , Dongao Han
Published: December 2017

Stellite 12 alloy was cladded on the surface of Thrust runner of a main pump using HIP technology. After product testing, lots of corrosions were found on the hard layer. SEM and EDS analysis technologies were used in order to find out the causes and mechanism inducing these corrosions. SEM results indicated that two kinds of corrosions locating on the hard layer. One type is central corrosion pit, another type is Selective Phase Corrosion (SPC).EDS showed that the central and adjacent corrosive areas were rich in carbon, low in cobalt, chromium and tungsten elements for the first type of corrosion. As for the second type of corrosion, EDS indicated that the corrosive zones were typically high in tungsten, chromium and carbon, and low in cobalt. Meanwhile, the presence of sulfur and chlorine elements may aggravate the initiation and continuation of corrosion.
Simulation of Behaviors of a One-Third Scale Containment Model Test
Authors: Ren Guopeng , Pan Rong , Sun Feng
Published: December 2017

Reactor containment of a nuclear power plant is a structure to ensure the safety of nuclear power plant. It acts as the last barrier to prevent the release of radioactive materials from NPP during accidents. Finite element models were established to simulate a 1/3 scale model of a reactor containment building under leakage test pressure. General finite element software ANSYS were applied. The nonlinear behavior of containment materials, geometric were taken into account in the analysis. The reliability of the finite element model was verified through the comparison of theoretical analysis results with experimental results. In the ANSYS finite element model, the concrete, steel bars and prestress tendons were separated and the prestress tendons were considered by the method of cooling method on the prestress tendon elements. The mechanical properties of the finite element model in the prestress tension process and the absolute internal pressure of 0.52MPa were analyzed.

Transient and time dependent losses were taken into account at the same time during the calculation of prestress of tendons, so as to calculate effective prestress at different locations of tendons. Calculation results of prestress losses show that the prestress losses at the hole of equipment hatch are larger than the other areas.

The results show that, the deformation of over-all structure of the containment is shrink inward under the action of prestress. And the simulation can achieve the consistent deformation effect between tendons and concrete. The maximum radial displacement of the whole containment structure is located at of 10 ° ∼ 20 °area on the right of the hole of the gate.

The effect of expansion deformation of the containment caused by design internal pressure is insufficient to offset the inward shrink effect generated by tendons, and the over-all structure of the concrete containment scale model is mainly under compressive stress. The containment test model is still with a large safety margin under the action of design internal pressure. The largest tensile stress is on the up and down areas of the internal sides of the equipment hatch, dome area close to ring beam, and bottom of perimeter wall close to the base slab. There is possibility of cracking on the concrete in limited local zones.

This benchmark can provide a reference for engineering design of containment.
Crystal Plasticity Modeling of Hot Extrusion Texture and Plasticity in a Titanium Alloy for an ICME Toolset
Authors: Ma Xianfeng , Ma Kan , Wu Yawen
Published: December 2017

For a better use of titanium alloy in nuclear industry, development of integrated computational materials engineering (ICME) model is necessary to optimize alloy microstructure and thus the performance of titanium component. Within an ICME toolset, constitutive models play an important role in quantitatively capturing the interrelationship between processing, microstructure and property. In this paper, texture evolution during hot extrusion of near-alpha Ti6242S bar were studied with respect to the deformation and transformation texture component. Experimentally measured alpha and beta phase textures were instantiated in a three dimensional rate-dependent crystal plasticity model. The model is able to accurately predict the deformation textures of both the alpha and beta phases at extrusion temperature. While decomposition of the metastable beta phase occurred during the post-extrusion cooling, most of the transformation texture components formed aligned [0001] with the extrusion direction, which formed the primary component of extruded alpha texture. The transformation texture was predicted by numerically decomposing the simulated beta texture according to appropriate variant selection rule. Also demonstrated was the capability of a crystal plasticity model incorporating microstructure information, such as phase fraction and lamellar spacing. The crystal plasticity model was validated by comparing with the experimental elastoplasticity behaviors of Ti6242S bars with various microstructures.
Discussion of Tag Gas Method Using in China Experimental Fast Reactor for Failed Fuel Assembly Location
Authors: Yewang Bie , Huwei Li , Wenbin Xiong , Donghui Zhang , Mingyu Wu , Xinzhe Wang
Published: December 2017

As the first fast reactor of China, the safety of CEFR is extremely important, and will decide the future of Chinese fast reactor project. The failed fuel detection system of CEFR provides surveillance and protection for the first barrier-fuel cladding of CEFR, so it is one of the most important systems for the safety of CEFR. As tag gas method is an important method for fuel-failure location in fast reactor, CEFR has a medium-term and long-term plan of using this method to locating failed fuel assemblies. This article introduces the main principle of tag gas method, summarizes the application of this method, and compares the advantages and disadvantages of each fuel failure location method. Combining the design characteristics of China Experimental Fast Reactor, this work analyzes the selection principle of tag gas isotopes and the effects on heat transfer capability of fuel element while tag gas filled in. Meanwhile, according to the detection ability of mass spectrometer and the foreign advanced utilization experiences of tag gas method, some suggestions are provided.
Thermal aging characterization of composite plates and honeycomb sandwiches by electromechanical measurement
Authors: Ndiaye Elhadji Barra , Duflo Hugues , Maréchal Pierre , Pareige Pascal
Published: December 2017

After identifying the parameters of the piezoelectric transducer, the mechanical impedance of the front medium is deduced. More particularly, the wave propagation velocity and attenuation are deduced in the inspected plate. By fitting the electrical impedance measurement results, the aging of composite materials is quantified, showing the effectiveness of this means of nondestructive evaluation. A specific measurement tool and protocol are proposed. Several estimators are identified on the basis of Gaussian fits of the resonances observed on the electrical impedance measurements. Those estimators are identified and the obtained results show that both the frequencies and widths of the resonances peaks vary according to the health of the plate, or aging duration. This method is applied successfully on non-perfect sandwich plates, porous, and with non-ideally flat surface. The sensitivity and limits of the most relevant estimators are discussed for the two studied plate families.
A human microglia-like cellular model for assessing the effects of neurodegenerative disease gene variants
Authors: Ryan Katie J. , White Charles C. , Patel Kruti , Xu Jishu , Olah Marta , Replogle Joseph M. , Frangieh Michael , Cimpean Maria , Winn Phoebe , McHenry Allison , Kaskow Belinda J. , Chan Gail , Cuerdon Nicole , Bennett David A. , Boyd Justin D. , Imitola Jaime , Elyaman Wassim , De Jager Philip L. , Bradshaw Elizabeth M.
Published: December 2017

A microglial-like cellular model can be used to identify functional consequences of genetic variants associated with neurodegenerative disease.
A homestay for your heart
Authors: Jewell Christopher M.
Published: December 2017

Heart-injectable hydrogels containing microRNA promote cardiomyocyte proliferation in mice after myocardial infarction.
Doctor won’t see you now: changing paradigms in mountain medicine
Authors: Szawarski Piotr , Hillebrandt David
Published: December 2017

The evolution in communication and digital technologies is revolutionising the practice of medicine. A physician is now able to oversee provision of healthcare at a distance. In this paper, we argue that practice of telemedicine is an essential and evolving aspect of high altitude and expedition medicine. We acknowledge the lack of international consensus, limited legislation as well as possible reservations towards telemedical practice. Given some unique social and medical aspects of participation in remote, high altitude expeditions we propose a number of guiding principles for those involved in provision of telemedical services for such endeavours.
A modified method for estimating permeability of clayey soils based on piezocone sounding results
Authors: Chai Jinchun , Chanmee Nachanok
Published: December 2017

A modified method for estimating permeability of clayey deposits in the horizontal direction (kh) based on piezocone sounding (uCPT) results is proposed. Most of the currently available methods relate the value of kh with the Δu/[Formula: see text] ratio (Δu is the measured excess pore pressure from uCPT at the shoulder of the cone and [Formula: see text] is the initial vertical effective stress at the measurement location). However, it has been understood that the effect of the overconsolidation ratio (OCR) on the Δu/[Formula: see text] ratio is more significant than that on the value of kh. As a result, for an overconsolidated deposit, there is no suitable method for estimating the value of kh based on uCPT results. Based on the results of laboratory model uCPT, an empirical equation for considering the effect of the OCR on Δu/[Formula: see text] and then kh corresponding to the yield vertical effective stress ([Formula: see text]) and initial vertical effective stress ([Formula: see text]) for OCR > 1.0 is established. The modified method for kh corresponding to [Formula: see text] requires two parameters: OCR and a model parameter (α). In addition, for kh corresponding to [Formula: see text], two more soil parameters are needed: the swelling index (Cs) and the initial void ratio (e0). The methods for estimating these parameters are also proposed. Finally, the modified method is applied to three field case histories to show its usefulness.
TNF-α antagonism with etanercept enhances penile NOS expression, cavernosal reactivity, and testosterone levels in aged rats
Authors: Demirtaş Şahin Tuğçe , Yazir Yusufhan , Utkan Tijen , Gacar Gulcin , Furat Rençber Selenay , Gocmez Semil Selcen
Published: December 2017

Erectile dysfunction (ED) has been reported to be associated with inflammation. This study investigated the effects of tumor necrosis factor alpha (TNF-α) inhibitor etanercept on penile neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) expressions, testosterone concentrations, neurogenic and endothelium-dependent relaxations of corpus cavernosum (CC), and circulating and cavernosal levels of inflammatory markers in aged rats. Animals were separated into control, aged, and etanercept-treated aged groups. Aged rats displayed significantly increased serum and cavernosal TNF-α, C-reactive protein (CRP), monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule (ICAM–1) levels, and decreased penile nNOS and eNOS expressions and serum testosterone levels compared with controls. In etanercept-treated aged group, NOS expressions were similar to that of the control group. The circulating and cavernosal concentrations of TNF-α, CRP, MCP-1, ICAM-1, and testosterone were also normalized by etanercept. Neurogenic and endothelium-dependent relaxant responses significantly decreased in aged rats and etanercept treatment markedly improved these relaxation responses. Our findings indicate that aging decreases penile NOS expression, neurogenic and endothelium-dependent relaxations of CC, and also suppresses serum testosterone levels by inducing inflammatory response that may contribute to the development of ED. TNF-α antagonism may be a novel strategy to treat aging-associated ED.
The right choice: predation pressure drives shell selection decisions in the hermit crabCalcinuscaliforniensis
Authors: Arce E. , Córdoba-Aguilar A.
Published: December 2017

Several prey species use refuges to avoid predation. Prey need to abandon and shift between refuges. However, during such shifting, prey can be vulnerable to predators. We hypothesize that predator presence may induce prey to make mistakes in choosing their refuge. We tested this by inducing the hermit crab Calcinus californiensis Bouvier, 1898 to shift to a new empty gastropod shell (three different species: Columbella Lamarck, 1799, Nerita scabricosta Lamarck, 1822, and Stramonita biserialis (Blainville, 1832)) in the absence and presence of Eriphia squamata Stimpson, 1860, which is an efficient shell-crushing natural crab predator. We expected that when a predator was present, hermit crabs would (i) inspect fewer shells and (or) (ii) change to a shell that is either too heavy to allow escape or unfit in size to accommodate the hermit crab. Although the first prediction was met, the second prediction was supported only when S. biserialis shells were used. Thus, in the presence of a predator, hermit crabs prioritize escaping by selecting lighter shells, which would allow the crab to move faster. We conclude that predator presence may induce prey to make mistakes in refuge selection, suggesting that this has severe consequences in future predatory events.
Gauge symmetry and the functional renormalization group
Authors: Itoh Katsumi
Published: December 2017

In the functional renormalization group (FRG), the introduction of a momentum cutoff often breaks symmetry present in a theory. The most important example is the gauge symmetry. However a symmetry survives in the presence of a cutoff in a modified form. We apply our understanding to QED as the simplest case. A modified version of the Ward–Takahashi identity is solved partially to constrain the Wilson action. Furthermore, we study the flow equation for the photon 2-point function and find its analytical expression for the regulator function of the exponential type.
Addressing the Cold Start with Positive-Only Feedback Through Semantic-Based Recommendations
Authors: Tomeo Paolo , Fernández-Tobías Ignacio , Cantador Iván , Di Noia Tommaso
Published: December 2017

Recommender systems aim to provide users with accurate item suggestions in a personalized fashion, but struggle in the case of cold start users, for whom there is a scarcity of preference data. User preferences can be either explicitly stated by the users — often by means of ratings —, or implicitly acquired by a system — for instance by mining text reviews, search queries, and purchase records. Recommendation methods have been mostly designed to deal with numerical ratings. However, real scenarios with user preferences expressed in the form of binary and unary (positive-only) feedback, e.g. the thumbs up/down in YouTube, and the likes in Facebook, are increasingly popular, and make the user cold start problem even more challenging. To address the cold start with positive-only feedback situations, we propose to exploit data additional to user preferences by means of specialized hybrid recommendation methods. In particular, we investigate a number of graph-based and matrix factorization recommendation models that jointly exploit user preferences and item semantic metadata automatically extracted from the well-known knowledge graph of DBpedia. Following a rigorous evaluation methodology for cold start, we empirically compare the above hybrid recommendation models on a Facebook dataset containing users likes for items in three different domains, namely books, movies and music. The achieved experimental results show that the semantics-aware hybrid approaches we propose outperform content-based and collaborative filtering baselines. In addition to recommendation accuracy, in our evaluation we also consider individual and aggregate diversity of recommendations as key quality factors in the users’ satisfaction.
Advancing Network Flow Information Using Collaborative Filtering
Authors: Fernández Diego , Nóvoa Francisco J. , Cacheda Fidel , Carneiro Víctor
Published: December 2017

Collaborative Filtering algorithms are frequently employed in e-commerce. However, this kind of algorithms can also be useful in other domains. In an information system thousands of bytes are sent through the network every second. Analyzing this data can require too much time and many resources, but it is necessary for ensuring the right operation of the network. Results are used for profiling, security analysis, traffic engineering and many other purposes.

Nowadays, as a complement to a deep inspection of the data, it is more and more common to monitor packet flows, since it consumes less resources and it allows to react faster to any network situation. In a typical ow monitoring system, flows are exported to a collector, which stores the information before being analyzed. However, many collectors work based on time slots, so they do not analyze the flows when they are just received, generating a delay.

In this work we demonstrate how Collaborative Filtering algorithms can be applied to this new domain. In particular, using information about past flows, these algorithms can anticipate future flows before being captured. This way, time required for detecting and responding to different network situations is reduced.
A Simple Explicit Meta-Model for Probabilistic Design of Dynamic Systems with Multiple Mixed Inputs
Authors: Son Young Kap , Savage Gordon J.
Published: December 2017

Most systems have multiple inputs that comprise of a mixture of excitations and component parameters. Excitations are different from component parameters in that they are always functions of time. In mechanical systems, these include applied forces, applied displacements, system settings, systems configurations and operating conditions. It would be convenient to include multiple excitations and multiple component parameters in a meta-model to take advantage of the inherent computation speed needed for timely probability-based design optimization.

In the development of the meta-model in this paper, we treat the component parameters in the same manner as the excitations and thus, in both cases, form time-sampled vectors. A design-of-experiments training regime creates a single input matrix, and using the mechanistic model, a single output matrix. Finally, a simple, explicit, meta-model is developed that turns an arbitrary vector of contiguous multiple excitations and multiple component parameters into the corresponding output vector (herein, the response). The approach provides an appealing and efficient solution to the multiple, mixed input problem, and in addition, requires only off-the-shelf computer software. The efficacy of the meta-model is shown through probability-based design optimization (PBDO) of a tire-wheel assembly, modelled as a mass-spring-damper system with nonlinear hysteresis, under a combination of practical inputs.
Designing Bayesian Reliability Sampling Plans for Weibull Lifetime Models Using Progressively Censored Data
Authors: Salem Maram , Amin Zeinab , Ismail Moshira
Published: December 2017

This paper presents Bayesian reliability sampling plans for the Weibull distribution based on progressively Type-II censored data with binomial removals. In constructing sampling plans, the decision theoretic approach is used. A dependent bivariate nonconjugate prior is employed. The total cost of the sampling plan consists of sampling, time-consuming, rejection, and acceptance costs. The decision rule is based on the Bayes estimator of the survival function. Lindley’s approximation is used to obtain Bayes estimates of the survival function under the quadratic and LINEX loss functions. However, the poor performance of Lindley’s approximation with small sample sizes can be observed. The Metropolis-within-Gibbs Markov Chain Monte Carlo (MCMC) algorithm show significantly improved performance compared to Lindley’s approximation. We use simulation studies to evaluate the Bayes risk and determine the optimal sampling plans for different sample sizes, observed number of failures, binomial removal probabilities and minimum acceptable reliability.
Effect of Different Connection Patterns of MUX and DEMUX on Terminal Reliability and Routing Scheme of Gamma-Minus MIN
Authors: Gupta Shilpa , Pahuja G. L.
Published: December 2017

In parallel and distributed systems, multistage interconnection network (MIN) plays an important role for its efficient communication between processor and memory at a very low cost. A major class of MIN called Gamma network is known for its redundant network topology and is being used in broadband communication systems. The increased redundancy incorporation makes these networks more complex and hence reliability evaluation becomes complex. The performance evaluation of these network topologies requires reliability evaluation utilizing routing mechanism or techniques. In this paper, we have proposed four topologies of Gamma-Minus network using MUX and DEMUX. Terminal Reliability (TR), fault tolerance and routing schemes of Gamma-Minus network topologies proposed have been computed by utilizing different connection patterns of MUX/DEMUX. Also, performance indices such as TR, Reliability Cost Ratio (RCR), Fault Tolerance, etc. computed for different Gamma-Minus architectures have been compared with the existing Gamma networks, other than Gamma-Minus. All the performance indices for different Gamma-Minus topologies show improvement over the performance indices of different Gamma networks. The proposed Gamma-Minus architectures have been compared among themselves and also Gamma-Minus2 shows the best performance for all performance indices. To the best of our knowledge, most of the researchers have not compared fault tolerance and RCR performance measure.
A Nonparametric Phase I Control Chart for Monitoring the Process Variability with Individual Observations Based on Empirical Likelihood Ratio
Authors: Huang Wei-Heng , Yeh Arthur B.
Published: December 2017

Among the statistical process control (SPC) techniques, the control chart has been proven to be effective in process monitoring. The Shewhart chart is one of the most commonly used control charts for monitoring the process mean and variability based on the assumption that the distribution of the quality characteristic is normal. However, in practice, many quality characteristics are not normally distributed.

Most of the existing nonparametric control charts are designed for Phase II monitoring. Little has been done in developing the nonparametric Phase I control charts especially for individual observations. In this work, we propose a new nonparametric Phase I control chart for monitoring the scale parameter based on the empirical likelihood ratio test. The simulation results show that the proposed chart is more effective than the existing charts in terms of signal probability. A real example is used to demonstrate how the proposed chart can be applied in practice.
Power law f(𝒢,T) gravity models supporting wormhole solutions
Authors: Shamir M. Farasat , Ahmad Mushtaq
Published: December 2017

This work provides some feasible regions for the existence of traversable wormhole geometries in modified [Formula: see text] gravity. For this purpose, three different matter contents have been studied with special emphasis on anisotropic fluid by considering a specific [Formula: see text] gravity power law model. It has been shown that the null energy conditions for the effective energy–momentum tensor are widely violated for the ordinary matter content. However, some small feasible regions to support the wormhole solutions have been noted. Furthermore, the stability of the anisotropic feasible regions for the wormhole solutions has been discussed. It is concluded that the wormhole geometries threaded by the ordinary matter actually exist and are well stable in [Formula: see text] gravity.
Low temperature oxidation synthesis of carbon encapsulated Cr2O3 nanocrystals and its lithium storage performance
Authors: Zhou Yun , Liu Boyang , Shao Yingfeng , Fan Chunhua , Fan Runhua , Wen Bosheng
Published: December 2017

A highly efficient and convenient strategy is developed for the one-step in-situ synthesis of carbon encapsulated Cr2O3 nanocrystals with core-shell structure (Cr2O3@C). The explosive reaction of chromocene with ammonium persulfate in an autoclave at 200[Formula: see text]C is crucial for the formation of this nanostructure. The Cr2O3 nanocrystals have a diameter of 5 to 20[Formula: see text]nm, which are entirely encapsulated by the amorphous carbon shell. The Cr2O3@C anode can retain a stable reversible capacity of 397[Formula: see text]mAh[Formula: see text]g[Formula: see text] after 50 cycles at a current density of 119[Formula: see text]mA g[Formula: see text].
Trio-Geometric mean-based three-stage Runge–Kutta algorithm to solve initial value problem arising in autonomous systems
Authors: Chauhan Vijeyata , Srivastava Pankaj Kumar
Published: December 2017

In the present worldwide scenario, plenty of problems arising in science and engineering which can be modeled as differential equations and out of these, autonomous system has become a subject of great interest. Several laws of physics in which time is considered as an independent variable are expressed as autonomous systems. In this paper, Runge–Kutta (RK) three-stage geometric mean method is used to solve the initial value problem arises in autonomous systems. The method is discussed in detail, convergence of method is discussed, the accuracy and efficiency of the method are proved by considering a numerical example. The result is compared to some other methods and proposed method is found to be more efficient. The detailed analysis of error estimation confirms that proposed method is more efficient as compared to other methods.
Using Online Geotagged and Crowdsourced Data to Understand Human Offline Behavior in the City
Authors: Zhang Yingjie , Li Beibei , Hong Jason
Published: December 2017

The pervasiveness of mobile technologies today has facilitated the creation of massive online crowdsourced and geotagged data from individual users at different locations in a city. Such ubiquitous user-generated data allow us to study the social and behavioral trajectories of individuals across both digital and physical environments. This information, combined with traditional economic and behavioral indicators in the city (e.g., store purchases, restaurant visits, parking), can help us better understand human behavior and interactions with cities. In this study, we take an economic perspective and focus on understanding human economic behavior in the city by examining the performance of local businesses based on the values learned from crowsourced and geotagged data. Specifically, we extract multiple traffic and human mobility features from publicly available data source geomapping and geo-social-tagging techniques and examine the effects of both static and dynamic features on booking volume of local restaurants. Our study is instantiated on a unique dataset of restaurant bookings from
OpenTable
for 3,187 restaurants in New York City from November 2013 to March 2014. Our results suggest that foot traffic can increase local popularity and business performance, while mobility and traffic from automobiles may hurt local businesses, especially the well-established chains and high-end restaurants. We also find that, on average, one or more street closure (caused by events or construction projects) nearby leads to a 4.7% decrease in the probability of a restaurant being fully booked during the dinner peak. Our study demonstrates the potential to best make use of the large volumes and diverse sources of crowdsourced and geotagged user-generated data to create matrices to predict local economic demand in a manner that is fast, cheap, accurate, and meaningful.
A Unified Model for User Identification on Multi-Touch Surfaces: A Survey and Meta-Analysis
Authors: Kharrufa Ahmed , Ploetz Thomas , Olivier Patrick
Published: December 2017

User identification on interactive surfaces is a desirable feature that is not inherently supported by existing technologies. We have conducted an extensive survey of existing identification techniques, which led us to formulate a unified model for user identification. We start by introducing this model that (1) classifies existing user identification approaches in five categories according to the identification technology, (2) identifies eight characteristic identification system parameters, and (3) proposes a way for visualizing the system's characteristics as points on a radar chart to allow for quick comparison and contrast between systems. This model is then used to present our survey of existing user identification approaches and visualize their characteristics, highlighting their strengths and limitations. The model also makes it possible to visually represent requirements of systems that require user identification, identify existing approaches that can meet an application's requirements, and help report on and evaluate new approaches to user identification systematically.
Synergistic CPU-GPU Frequency Capping for Energy-Efficient Mobile Games
Authors: Park Jurn-Gyu , Hsieh Chen-Ying , Dutt Nikil , Lim Sung-Soo
Published: December 2017

Mobile platforms are increasingly using Heterogeneous Multiprocessor Systems-on-Chip (HMPSoCs) with differentiated processing cores and GPUs to achieve high performance for graphics-intensive applications such as mobile games. Traditionally, separate CPU and GPU governors are deployed in order to achieve energy efficiency through Dynamic Voltage Frequency Scaling (DVFS) but miss opportunities for further energy savings through coordinated system-level application of DVFS. We present a cooperative CPU-GPU DVFS strategy (called Co-Cap) that orchestrates energy-efficient CPU and GPU DVFS through synergistic CPU and GPU frequency capping to avoid frequency overprovisioning while maintaining desired performance. Unlike traditional approaches that target a narrow set of mobile games, our Co-Cap approach is applicable across a wide range of microbenchmarks and mobile games. Our methodology employs a systematic training phase using fine-grained refinement steps with evaluations of frequency capping tables followed by a deployment phase, allowing deployment across a wide range of microbenchmarks and mobile games with varying graphics workloads. Our experimental results across multiple sets of over 200 microbenchmarks and 40 mobile games show that Co-Cap improves energy per frame by on average 8.9% (up to 18.3%) and 7.8% (up to 27.6%) (16.6% and 15.7% in CPU-dominant applications) and achieves minimal frames-per-second (FPS) loss by 0.9% and 0.85% (1.3% and 1.5% in CPU-dominant applications) on average in training and deployment sets, respectively, compared to the default CPU and GPU governors, with negligible overhead in execution time and power consumption on the ODROID-XU3 platform.
What You Lose When You Snooze
Authors: Biondi Elisabetta , Boldrini Chiara , Passarella Andrea , Conti Marco
Published: December 2017

In opportunistic networks, putting devices in energy-saving mode is crucial to preserve their battery, and hence to increase the lifetime of the network and foster user participation. A popular strategy for energy saving is duty cycling. However, when in energy-saving mode, users cannot communicate with each other. The side effects of duty cycling are twofold. On the one hand, duty cycling may reduce the number of usable contacts for delivering messages, increasing
intercontact
times, and delays. On the other hand, duty cycling may break long contacts into smaller contacts, thus also reducing the capacity of the opportunistic network. Despite the potential serious effects, the role played by duty cycling in opportunistic networks has been often neglected in the literature. In order to fill this gap, in this article, we propose a general model for deriving the pairwise contact and intercontact times measured when a duty cycling policy is superimposed on the original encounter process determined only by node mobility. The model we propose is general, i.e., not bound to a specific distribution of contact and intercontact times, and very accurate, as we show exploiting two traces of real human mobility for validation. Using this model, we derive several interesting results about the properties of measured contact and intercontact times with duty cycling: their distribution, how their coefficient of variation changes depending on the duty cycle value, and how the duty cycling affects the capacity and delay of an opportunistic network. The applicability of these results is broad, ranging from performance models for opportunistic networks that factor in the duty cycling effect, to the optimisation of the duty cycle to meet a certain target performance.
Implicit Emotion Communication
Authors: Ceballos Rodrigo , Ionascu Beatrice , Park Wanjoo , Eid Mohamad
Published: December 2017

Today, ubiquitous digital communication systems do not have an intuitive, natural way of communicating emotion, which, in turn, affects the degree to which humans can emotionally connect and interact with one another. To address this problem, a more natural, intuitive, and implicit emotion communication system was designed and created that employs asymmetry-based EEG emotion classification for detecting the emotional state of the sender and haptic feedback (in the form of tactile gestures) for displaying emotions for a receiver. Emotions are modeled in terms of valence (positive/negative emotions) and arousal (intensity of the emotion). Performance analysis shows that the proposed EEG subject-dependent emotion classification model with Free Asymmetry features allows for more flexible feature-generation schemes than other existing algorithms and attains an average accuracy of 92.5% for valence and 96.5% for arousal, outperforming previous-generation schemes in high feature space. As for the haptic feedback, a tactile gesture authoring tool and a haptic jacket were developed to design tactile gestures that can intensify emotional reactions in terms of valence and arousal. Experimental study demonstrated that subject-independent emotion transmission through tactile gestures is effective for the arousal dimension of an emotion but is less effective for valence. Consistency in subject-dependent responses for both valence and arousal suggests that personalized tactile gestures would be more effective.
CAIRO
Authors: Hadidi Ramyad , Nai Lifeng , Kim Hyojong , Kim Hyesoon
Published: December 2017

Three-dimensional (3D)-stacking technology and the memory-wall problem have popularized processing-in-memory (PIM) concepts again, which offers the benefits of bandwidth and energy savings by offloading computations to functional units inside the memory. Several memory vendors have also started to integrate computation logics into the memory, such as Hybrid Memory Cube (HMC), the latest version of which supports up to 18 in-memory atomic instructions. Although industry prototypes have motivated studies for investigating efficient methods and architectures for PIM, researchers have not proposed a systematic way for identifying the benefits of
instruction-level PIM offloading
. As a result, compiler support for recognizing offloading candidates and utilizing instruction-level PIM offloading is unavailable. In this article, we analyze the advantages of instruction-level PIM offloading in the context of HMC-atomic instructions for graph-computing applications and propose
CAIRO
, a compiler-assisted technique and decision model for enabling instruction-level offloading of PIM without any burden on programmers. To develop CAIRO, we analyzed how instruction offloading enables performance gain in both CPU and GPU workloads. Our studies show that performance gain from bandwidth savings, the ratio of number of cache misses to total cache accesses, and the overhead of host atomic instructions are the key factors in selecting an offloading candidate. Based on our analytical models, we characterize the properties of beneficial and nonbeneficial candidates for offloading. We evaluate CAIRO with 27 multithreaded CPU and 36 GPU benchmarks. In our evaluation, CAIRO not only doubles the speedup for a set of PIM-beneficial workloads by exploiting HMC-atomic instructions but also prevents slowdown caused by incorrect offloading decisions for other workloads.
Weyl Metals
Authors: Burkov A.A.
Published: December 2017

Weyl metal is the first example of a conducting material with a nontrivial electronic structure topology, making it distinct from an ordinary metal. Unlike in insulators, the nontrivial topology is not related to invariants associated with completely filled bands but with ones associated with the Fermi surface. The Fermi surface of a topological metal consists of disconnected sheets, each enclosing a Weyl node, which is a point of contact between two nondegenerate bands. Such a point contact acts as a source of Berry curvature or a magnetic monopole in momentum space. Its charge, or the flux of the Berry curvature through the enclosing Fermi surface sheet, is a topological invariant. We review the current state of this rapidly growing field with a focus on bulk transport phenomena in topological metals.
Mitochondrial content is preserved throughout disease progression in the mdx mouse model of Duchenne muscular dystrophy, regardless of taurine supplementation
Authors: Barker Robert G. , Wyckelsma Victoria L. , Xu Hongyang , Murphy Robyn M.
Published: December 2017

Mitochondrial dysfunction is a pathological feature of Duchenne muscular dystrophy (DMD), a debilitating and fatal neuromuscular disorder characterized by progressive muscle wasting and weakness. Mitochondria are a source of cellular ATP involved in Ca2+ regulation and apoptotic signaling. Ameliorating aberrant mitochondrial function has therapeutic potential for reducing DMD disease severity. The dystrophic mdx mouse exhibits peak muscle damage at 21–28 days, which stabilizes after 8 wk. The amino acid taurine is implicated in mitochondrial health and function, with endogenous concentrations low when measured during the cycle of peak muscle damage in mdx mice. Using whole soleus and extensor digitorum longus (EDL) muscle homogenates from 28- and 70-day mdx mice, we found that there was no change in native state mitochondrial complexes using blue native-PAGE. NADH:ubiquinone oxidotreductase subunit-A9 (NDUFA9) protein abundance was lower in soleus muscle of 28- and 70-day mdx mice and EDL muscle of 70-day mdx mice compared with same muscles in WT (C57/BL10ScSn) animals. There were age-dependent increases in both NDUFA9 protein abundance and citrate synthase activity in soleus muscles of mdx and wild-type mice. There was no change in abundances of mitochondrial dynamics proteins mitofusin 2 (Mfn2) and mitochondrial dynamics protein 49 (MiD49). Taurine administration essentially did not affect any measurements of mitochondria. Collectively, these findings suggest mitochondrial content and dynamics are not reduced in the mdx mouse regardless of disease severity. We also elucidate that taurine affords no significant benefit to mitochondrial content or dynamics in the mdx mouse at either 28 or 70 days.
The murine choroid plexus epithelium expresses the 2Cl−/H+ exchanger ClC-7 and Na+/H+ exchanger NHE6 in the luminal membrane domain
Authors: Damkier Helle H. , Christensen Henriette L. , Christensen Inga B. , Wu Qi , Fenton Robert A. , Praetorius Jeppe
Published: December 2017

The choroid plexus epithelium within the brain ventricles secretes the majority of the cerebrospinal fluid (CSF). The luminal Na+-K+-ATPase acts in concert with a host of other transport proteins to mediate efficient fluid secretion across the epithelium. The CSF contains little protein buffer, but the pH value seems nonetheless maintained within narrow limits, even when faced with acid-base challenges. The involvement of choroid plexus acid-base transporters in CSF pH regulation is highlighted by the expression of several acid-base transporters in the epithelium. The aim of the present study was to identify novel acid-base transporters expressed in the luminal membrane of the choroid plexus epithelium to pave the way for systematic investigations of each candidate transporter in the regulation of CSF pH. Mass spectrometry analysis of proteins from epithelial cells isolated by fluorescence-activated cell sorting identified the Cl−/H+ exchangers ClC-3, -4, -5, and -7 in addition to known choroid plexus acid-base transporters. RT-PCR on FACS isolated epithelial cells confirmed the expression of the corresponding mRNAs, as well as Na+/H+ exchanger NHE6 mRNA. Both NHE6 and ClC-7 were immunolocalized to the luminal plasma membrane domain of the choroid plexus epithelial cells. Dynamic imaging of intracellular pH and membrane potential changes in isolated choroid plexus epithelial cells demonstrated Cl− gradient-driven changes in intracellular pH and membrane potential that are consistent with Cl−/H+ exchange. In conclusion, we have detected for the first time NHE6 and ClC-7 in the choroid plexus, which are potentially involved in pH regulation of the CSF.
AMP-activated protein kinase and adenosine are both metabolic modulators that regulate chloride secretion in the shark rectal gland (Squalus acanthias)
Authors: Neuman Rugina I. , van Kalmthout Juliette A. M. , Pfau Daniel J. , Menendez Dhariyat M. , Young Lawrence H. , Forrest John N.
Published: December 2017

The production of endogenous adenosine during secretagogue stimulation of CFTR leads to feedback inhibition limiting further chloride secretion in the rectal gland of the dogfish shark (Squalus acanthias). In the present study, we examined the role of AMP-kinase (AMPK) as an energy sensor also modulating chloride secretion through CFTR. We found that glands perfused with forskolin and isobutylmethylxanthine (F + I), potent stimulators of chloride secretion in this ancient model, caused significant phosphorylation of the catalytic subunit Thr172 of AMPK. These findings indicate that AMPK is activated during energy-requiring stimulated chloride secretion. In molecular studies, we confirmed that the activating Thr172 site is indeed present in the α-catalytic subunit of AMPK in this ancient gland, which reveals striking homology to AMPKα subunits sequenced in other vertebrates. When perfused rectal glands stimulated with F + I were subjected to severe hypoxic stress or perfused with pharmacologic inhibitors of metabolism (FCCP or oligomycin), phosphorylation of AMPK Thr172 was further increased and chloride secretion was dramatically diminished. The pharmacologic activation of AMPK with AICAR-inhibited chloride secretion, as measured by short-circuit current, when applied to the apical side of shark rectal gland monolayers in primary culture. These results indicate that that activated AMPK, similar to adenosine, transmits an inhibitory signal from metabolism, that limits chloride secretion in the shark rectal gland.
Na regulates growth of kidney epithelial cells induced by lowering extracellular K concentration
Authors: Walsh-Reitz M. M. , Aithal H. N. , Toback F. G.
Published: December 2017

Accelerated kidney growth and increased tissue Na content have been observed in rats fed a K-deficient diet. These observations suggest that enhanced Na influx could mediate renal growth, a hypothesis that was tested in cultures of kidney epithelial cells of the BSC-1 line. Reduction of the K concentration in the culture medium from 5.4 to 3.2 mM augmented cell growth and induced a transient increase in the cellular content of Na and a decrease in that of K. That low-K-induced growth was Na dependent was shown by decreasing the medium Na concentration from 155 to 150 mM, which abolished the increases in both growth and cell Na content in a concentration-dependent manner. The stimulation of glyceraldehyde-3-phosphate dehydrogenase (G3PD) activity that occurs in cells exposed to low-K medium for 1 h was similarly prevented by decreasing the medium Na concentration. Thus decreased availability of extracellular Na prevented the increase in cell Na content, stimulation of G3PD activity, and accelerated growth induced by low-K medium. The hypothesis was also tested by adding vasopressin to cultures of BSC-1 cells exposed to low-K medium; the hormone prevented the increments in cell Na content, G3PD activity, and growth to the same extent as did decreased availability of extracellular Na. These results are consistent with the interpretation that transient accumulation of Na is a critical determinant of the initiation of kidney epithelial cell growth.