bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Nonlinear Identification SOFC Temperature Model Based on Particle Swarm Optimization–Least-Squares Support Vector Regression
Authors: Chen Jinwei , Zhang Huisheng , Weng Shilie
Published: May 2017

In order to facilitate valid solid oxide fuel cell (SOFC) temperature control scheme, a nonlinear identification method of SOFC temperature dynamic behaviors is proposed using an autoregressive network with exogenous inputs (NARX) model, whose nonlinear function is described by a least-squares support vector regression (LSSVR) method with radial basis kernel function (RBF). During the identifying process, a particle swarm optimization (PSO) algorithm is introduced to optimize the parameters of LSSVR. On the other hand, a mechanism model is developed to sample the training data to regress the NARX model. Investigations are conducted to analyze the effects of training data size and PSO fitness function on the accuracy of the NARX model. The results demonstrate that the NARX model with tenfold cross-validation fitness function and large size data is precise enough in predicting the SOFC temperature dynamic behaviors. The maximum errors of cathode and anode outlet temperature are 0.3081 K and 0.3293 K, respectively. Furthermore, the simulation speed of NARX model is much faster than the mechanism model because NARX model avoids the internal complex computation process. The training time of the NARX model with large size data is about 1.2 s. For a 20,000 s simulation, the predicting time of the NARX model is about 0.2 s, while the mechanism model is about 36 s. In consideration of its high computational speed and accuracy, NARX model is a powerful candidate for valid multivariable model predictive control (MPC) schemes.
Effects of the Fractional Laplacian Order on the Nonlocal Elastic Rod
Response
Authors: Autuori Giuseppina , Cluni Federico , Gusella Vittorio , Pucci Patrizia
Published: May 2017

In this paper, we yield with a nonlocal elastic rod problem, widely studied in the last decades. The main purpose of the paper is to investigate the effects of the statistic variability of the fractional operator order s on the displacements u of the rod. The rod is supposed to be subjected to external distributed forces, and the displacement field u is obtained by means of numerical procedure. The attention is particularly focused on the parameter s, which influences the response in a nonlinear fashion. The effects of the uncertainty of s on the response at different locations of the rod are investigated by the Monte Carlo simulations. The results obtained highlight the importance of s in the probabilistic feature of the response. In particular, it is found that for a small coefficient of variation of s, the probability density function of the response has a unique well-identifiable mode. On the other hand, for a high coefficient of variation of s, the probability density function of the response decreases monotonically. Finally, the coefficient of variation and, to a small extent, the mean of the response tend to increase as the coefficient of variation of s increases.
Linear Matrix Inequality Based Fractional Integral Sliding-Mode Control of Uncertain Fractional-Order Nonlinear Systems
Authors: Dadras Sara , Dadras Soodeh , Momeni HamidReza
Published: May 2017

A design of linear matrix inequality (LMI)-based fractional-order surface for sliding-mode controller of a class of uncertain fractional-order nonlinear systems (FO-NSs) is proposed in this paper. A new switching law is achieved guaranteeing the reachability condition. This control law is established to obtain a sliding-mode controller (SMC) capable of deriving the state trajectories onto the fractional-order integral switching surface and maintain the sliding motion. Using LMIs, a sufficient condition for existence of the sliding surface is derived which ensures the t−α asymptotical stability on the sliding surface. Through a numerical example, the superior performance of the new fractional-order sliding mode controller is illustrated in comparison with a previously proposed method.
Actuator Design and Flight Testing of an Active Microspoiler-Equipped Projectile
Authors: Kim Dooroo , Strickland Laura , Gross Matthew , Rogers Jonathan , Costello Mark , Fresconi Frank , Celmins Ilmars
Published: May 2017

Actively controlled gun-launched projectiles require a means of modifying the projectile flight trajectory. While numerous potential mechanisms exist, microspoiler devices have been shown to be a promising control actuator for fin-stabilized projectiles in supersonic flight. These devices induce a trim force and moment generated by the boundary layer–shock interaction between the projectile body, rear stabilizing fins, and microspoilers. Previous investigations of microspoiler mechanisms have established estimates of baseline control authority, but experimental results have been restricted to cases in which the mechanism was statically deployed. This paper details the design and flight testing of a projectile equipped with a set of active microspoilers. A mechanical actuator is proposed that exhibits unique advantages in terms of robustness, simplicity, gun-launch survivability, and bandwidth compared to other projectile actuator mechanisms considered to date. A set of integrated test projectiles is constructed using this actuator design, and flight experiments are performed in which the microspoilers are oscillated near the projectile roll frequency. Data obtained from these flight tests are used in parameter estimation studies to experimentally characterize the aerodynamic effects of actively oscillating microspoilers. These predictions compare favorably with estimates obtained from computational fluid dynamics (CFD). Overall, the results presented here demonstrate that actively controlled microspoilers can generate reasonably high levels of lateral acceleration suitable for trajectory modification in many smart-weapons applications.
Fuel Cell Temperature Control With a Precombustor in SOFC Gas Turbine Hybrids During Load Changes
Authors: Zaccaria Valentina , Branum Zachary , Tucker David
Published: May 2017

The use of high temperature fuel cells, such as solid oxide fuel cells (SOFCs), for power generation is considered a very efficient and clean solution for conservation of energy resources. When the SOFC is coupled with a gas turbine, the global system efficiency can go beyond 70% on natural gas lower heating value (LHV). However, durability of the ceramic material and system operability can be significantly penalized by thermal stresses due to temperature fluctuations and noneven temperature distributions. Thermal management of the cell during load following is therefore essential. The purpose of this work is to develop and test a precombustor model for real-time applications in hardware-based simulations, and to implement a control strategy to keep constant cathode inlet temperature during different operative conditions. The real-time model of the precombustor was incorporated into the existing SOFC model and tested in a hybrid system facility, where a physical gas turbine and hardware components were coupled with a cyber-physical fuel cell for flexible, accurate, and cost-reduced simulations. The control of the fuel flow to the precombustor was proven to be effective in maintaining a constant cathode inlet temperature during a step change in fuel cell load. With a 20 A load variation, the maximum temperature deviation from the nominal value was below 0.3% (3 K). Temperature gradients along the cell were maintained below 10 K/cm. An efficiency analysis was performed in order to evaluate the impact of the precombustor on the overall system efficiency.
Prediction of Direct Methanol Fuel Cell Stack Performance Using Artificial Neural Network
Authors: Rafe Biswas M. A. , Robinson Melvin D.
Published: May 2017

A direct methanol fuel cell (DMFC) converts liquid fuel into electricity to power devices, while operating at relatively low temperatures and producing virtually no greenhouse gases. Since DMFC performance characteristics are inherently complex, it can be postulated that artificial neural networks (NN) represent a marked improvement in prediction capabilities. In this work, an artificial NN is employed to predict the performance of a DMFC under various operating conditions. Input variables for the analysis consist of methanol concentration, temperature, current density, number of cells, and anode flow rate. The addition of the two latter variables allows for a more distinctive model when compared to prior NN models. The key performance indicator of our NN model is cell voltage, which is an average voltage across the stack and ranges from 0 to 0.8 V. Experimental studies were conducted using DMFC stacks with membrane electrode assemblies consisting of an additional unique liquid barrier layer to minimize water loss to atmosphere. To determine the best fit to the experimental data, the model is trained using two second-order training algorithms: OWO-Newton and Levenberg–Marquardt (LM). The topology of OWO-Newton algorithm is slightly different from that of LM algorithm by employing bypass weights. The application of NN shows rapid construction of a predictive model of cell voltage for varying operating conditions with an accuracy on the order of 10−4, which can be comparable to literature. The coefficient of determination of the optimal model results using either algorithm were greater than 0.998.
A Preliminary Experimental Study About Two-Sided Impacting SDOF Oscillator Under Harmonic Excitation
Authors: Andreaus Ugo , Baragatti Paolo , De Angelis Maurizio , Perno Salvatore
Published: May 2017

Shaking table tests have been carried out to investigate the pounding phenomenon between a mass and two-sided shock absorbers, subject to sinusoidal excitations. In an effort to investigate the effectiveness of such an impact mitigation measure, preliminary tests were carried out: first, the dynamic response was recorded without pounding, and second, the test structure was placed with gap separation and pounding was induced. Absolute acceleration, relative excursion, mean contact force, coefficient of restitution, and dissipated energy were recorded at steady state and the excitation frequency range for pounding occurrences was determined. Numerical predictions were made by using a contact model for the simulation of impacts, able to appropriately describe the behavior of rubber under impact loading. Good agreement between the experimental and the numerical results was achieved.
Negative Consequences of Low Energy Availability in Natural Male Bodybuilding: A Review
Authors: Fagerberg Petter
Published: May 2017

Energy availability (EA) is a scientific concept describing how much energy is available for basic metabolic functions such as reproduction, immunity, and skeletal homeostasis. Carefully controlled studies on women have shown pathological effects of EA < 30 kcal/kg fat-free mass (FFM), and this state has been labeled low EA (LEA). Bodybuilding is a sport in which athletes compete to show muscular definition, symmetry, and low body fat (BF). The process of contest preparation in bodybuilding includes months of underfeeding, thus increasing the risk of LEA and its negative health consequences. As no well-controlled studies have been conducted in natural male bodybuilders on effects of LEA, the aim of this review was to summarize what can be extrapolated from previous relevant research findings in which EA can be calculated. The reviewed literature indicates that a prolonged EA < 25 kcal/kg FFM results in muscle loss, hormonal imbalances, psychological problems, and negatively affects the cardiovascular system when approaching the lower limits of BF (∼4%–5%) among males. Case studies on natural male bodybuilders who prepare for contest show muscle loss (>40% of total weight loss) with EA < 20 kcal/kg FFM, and in the study with the lowest observed BF (∼4 kg), major mood disturbance and hormonal imbalances co-occurred. Studies also underline the problem of BF overshoot during refeeding after extremes of LEA among males. A more tempered approach (EA > 25 kcal/kg FFM) might result in less muscle loss among natural male bodybuilders who prepare for contest, but more research is needed.
Carbohydrates Alone or Mixing With Beef or Whey Protein Promote Similar Training Outcomes in Resistance Training Males: A Double-Blind, Randomized Controlled Clinical Trial
Authors: Naclerio Fernando , Seijo Marcos , Larumbe-Zabala Eneko , Earnest Conrad P.
Published: May 2017

Beef powder is a new high-quality protein source scarcely researched relative to exercise performance. The present study examined the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on strength performance (1RM), body composition (via plethysmography), limb circumferences and muscular thickness (via ultrasonography), following an 8-week resistance-training program. After being randomly assigned to one of the following groups: Beef, Whey, or Carbohydrate, twenty four recreationally physically active males (n = 8 per treatment) ingested 20 g of supplement, mixed with orange juice, once a day (immediately after workout or before breakfast). Post intervention changes were examined as percent change and 95% CIs. Beef (2.0%, CI, 0.2–2.38%) and Whey (1.4%, CI, 0.2–2.6%) but not Carbohydrate (0.0%, CI, -1.2–1.2%) increased fat-free mass. All groups increased vastus medialis thickness: Beef (11.1%, CI, 6.3–15.9%), Whey (12.1%, CI, 4.0, -20.2%), Carbohydrate (6.3%, CI, 1.9–10.6%). Beef (11.2%, CI, 5.9–16.5%) and Carbohydrate (4.5%, CI, 1.6–7.4%), but not Whey (1.1%, CI, -1.7–4.0%), increased biceps brachialis thickness, while only Beef increased arm (4.8%, CI, 2.3–7.3%) and thigh (11.2%, 95%CI 0.4–5.9%) circumferences. Although the three groups significantly improved 1RM Squat (Beef 21.6%, CI 5.5–37.7%; Whey 14.6%, CI, 5.9–23.3%; Carbohydrate 19.6%, CI, 2.2–37.1%), for the 1RM bench press the improvements were significant for Beef (15.8% CI 7.0–24.7%) and Whey (5.8%, CI, 1.7–9.8%) but not for carbohydrate (11.4%, CI, -0.9-23.6%). Protein-carbohydrate supplementation supports fat-free mass accretion and lower body hypertrophy. Hydrolyzed beef promotes upper body hypertrophy along with similar performance outcomes as observed when supplementing with whey isolate or maltodextrin.
Energy Requirement Assessment in Japanese Table Tennis Players Using the Doubly Labeled Water Method
Authors: Sagayama Hiroyuki , Hamaguchi Genki , Toguchi Makiko , Ichikawa Mamiko , Yamada Yosuke , Ebine Naoyuki , Higaki Yasuki , Tanaka Hiroaki
Published: May 2017

Total daily energy expenditure (TEE) and physical activity level (PAL) are important for adequate nutritional management in athletes. The PAL of table tennis has been estimated to about 2.0: it is categorized as a moderateactivity sport (4.0 metabolic equivalents [METs]) in the Compendium of Physical Activities. However, modern table tennis makes high physiological demands. The aims of the current study were to examine (1) TEE and PAL of competitive table tennis players and (2) the physiological demands of various types of table tennis practice. In Experiment 1, we measured TEE and PAL in 10 Japanese college competitive table tennis players (aged 19.9 ± 1.1 years) using the doubly labeled water (DLW) method during training and with an exercise training log and self-reported energy intake. TEE was 15.5 ± 1.9 MJ·day-1 (3695 ± 449 kcal·day-1); PAL was 2.53 ± 0.25; and the average training duration was 181 ± 38 min·day-1. In Experiment 2, we measured METs of five different practices in seven college competition players (20.6 ± 1.2 years). Three practices without footwork were 4.5–5.2 METs, and two practices with footwork were 9.5–11.5 METs. Table tennis practices averaged 7.1 ± 3.2 METS demonstrating similarities with other vigorous racket sports. In conclusion the current Compendium of Physical Activities underestimates the physiological demands of table tennis practice for competition; the estimated energy requirement should be based on DLW method data.
The Effect of Backpack Load Carriage on the Kinetics and Kinematics of Ankle and Knee Joints During Uphill Walking
Authors: Lee Jinkyu , Yoon Yong-Jin , Shin Choongsoo S.
Published: May 2017

The purpose of this study was to investigate the effect of load carriage on the kinematics and kinetics of the ankle and knee joints during uphill walking, including joint work, range of motion (ROM), and stance time. Fourteen males walked at a self-selected speed on an uphill (15°) slope wearing military boots and carrying a rifle in hand without a backpack (control condition) and with a backpack. The results showed that the stance time significantly decreased with backpack carriage (p < .05). The mediolateral impulse significantly increased with backpack carriage (p < .05). In the ankle joints, the inversion-eversion, and dorsi-plantar flexion ROM in the ankle joints increased with backpack carriage (p < .05). The greater dorsi-plantar flexion ROM with backpack carriage suggested 1 strategy for obtaining high plantar flexor power during uphill walking. The result of the increased mediolateral impulse and inversion-eversion ROM in the ankle joints indicated an increase in body instability caused by an elevated center of mass with backpack carriage during uphill walking. The decreased stance time indicated that an increase in walking speed could be a compensatory mechanism for reducing the instability of the body during uphill walking while carrying a heavy backpack.
The Effect of Stride Length and Lateral Pelvic Tilt on Elbow Torque in Youth Baseball Pitchers
Authors: Tocci Noah X. , Howell David R. , Sugimoto Dai , Dawkins Corey , Whited Amy , Bae Donald
Published: May 2017

High elbow torque during a pitch may contribute to injury risk. Our objective was to determine the pitch mechanics associated with elbow varus torque in youth baseball pitchers. Eighteen male youth pitchers (age = 15.5 ± 1.6 years) threw 3 fastballs and 3 change-ups from a windup position while undergoing 3-dimensional kinematic analysis. Independent variables included ball release point distance, stride length, lateral pelvic tilt, and ball velocity. Two multiple regression models, separated by pitch type (fastball, change-up) were used to determine the association of independent variables with peak varus torque at the elbow. Fastball and change-up regression models indicated that stride length (β = 0.301, p = .015; β = 0.46, p < .001, respectively) and lateral pelvic tilt (β = −0.50, p < .001; β = −0.25, p = .04, respectively) were significantly associated with peak elbow varus torque. During fastballs, pitch velocity was significantly associated with peak elbow varus torque (β = 0.38, p = .002), while release point distance was significantly associated with peak elbow varus torque during change-ups (β = −0.33, p = .015). Youth pitchers with longer strides and less lateral pelvic tilt demonstrated greater elbow torque regardless of pitch type, while the association of ball velocity and release point to elbow varus torque was dependent on pitch type.
Predictors of Physical Activity Levels in Community-Dwelling Older Adults: A Multivariate Approach Based on a Socio-Ecological Framework
Authors: Fisher Koren L. , Harrison Elizabeth L. , Bruner Brenda G. , Lawson Joshua A. , Reeder Bruce A. , Ashworth Nigel L. , Sheppard M. Suzanne , Chad Karen E.
Published: May 2017

The purpose of this study was to explore cross-sectional relationships between self-reported physical activity (PA) and personal, social, and environmental factors in community-dwelling adults aged 50 years and older. Accounting for clustering by neighborhood, generalized estimating equations were used to examine associations between selected correlates and the Physical Activity Scale for the Elderly (PASE) score while adjusting for confounders. Data for 601 participants were analyzed: 79% female, 37% married, mean age 76.8 (± 8.7) years, mean PASE score 112.6 (± 64.8). Age, living in seniors’ housing, using nursing/home care services, receiving encouragement to be active, and having benches available in the neighborhood were inversely associated with PASE. Self-efficacy, SF-12 score, PA barriers, social support, and the presence of trails showed positive associations. Several personal, social, and environmental factors associated with PA were identified. The inverse association between PA and living in seniors’ housing units should be considered when developing PA programs for older adults.
Sedentary Time in Male and Female Masters and Recreational Athletes Aged 55 and Older
Authors: McCracken Heather , Dogra Shilpa
Published: May 2017

The purpose of this study was to quantify sedentary time among recreational and Masters (competitive) athletes aged 55 and older. A cross-sectional survey including questions on demographics, sport participation, as well as a short form of the International Physical Activity Questionnaire, and the Measure of Older Adult’s Sedentary Time questionnaire was administered (n = 203). Male Masters athletes reported more time spent in vigorous intensity physical activity and less time watching TV than recreational athletes. Among females, being a Masters athlete was associated with being more sedentary than being a recreational athlete, while among males, being a recreational athlete was associated with being more sedentary. The intensity and duration that older Masters and recreational athletes spent in their sport was inversely associated with the amount of sedentary time accumulated. Future research using inclinometers is needed to further elucidate sedentary time in older male and female athletes.
The Validity of Consumer-Level Activity Monitors in Healthy Older Adults in Free-Living Conditions
Authors: Farina Nicolas , Lowry Ruth G.
Published: May 2017

Consumer-level activity monitors, such as Fitbit and Misfit devices, are a popular and low-cost means of measuring physical activity. This study aims to compare the accuracy of step counts from two consumer-level activity monitors against two reference devices in healthy, community-dwelling older adults in free-living conditions. Twenty-five older adults (aged 65–84) simultaneously wore 5 devices (e.g., Misfit Shine and Fitbit Charge HR) over 7 consecutive days. All consumer-level activity monitors positively correlated with reference devices (p < .001). There was also substantial to near perfect agreement between all consumer-level activity monitors and reference devices. Compared to the ActiGraph GT3X+, the waist-worn Misfit Shine displayed the highest agreement amongst the devices worn (ICC = 0.96, 95% 0.91 to 0.99). The wrist-worn devices showed poorer agreement to reference devices. Future research needs to consider that not all consumer-level activity monitors are equal in terms of accuracy, design, and function.
Facilitators of Attendance and Adherence to Group-Based Physical Activity for Older Adults: A Literature Synthesis
Authors: de Lacy-Vawdon Cassandra J. , Klein Ruth , Schwarzman Joanna , Nolan Genevieve , de Silva Renee , Menzies David , Smith Ben J.
Published: May 2017

This review examines program features that influence attendance and adherence to group-based physical activity (PA) by older adults. Medline, PubMed, CINAHL plus, PsycINFO, and the Cochrane Library were searched for studies published from 1995–2016. Quantitative and qualitative studies investigating factors related to PA group attendance or adherence by persons aged 55 years and over were included. Searching yielded eight quantitative and 13 qualitative studies, from 2,044 titles. Quantitative findings identified social factors, instructor characteristics, PA types, class duration and frequency, and perceived PA outcomes as important for attendance and adherence, whilst qualitative studies identified settings, leadership, PA types, observable benefits, and social support factors. Studies were predominantly low- to moderate-quality. This review identified design and delivery considerations for group-based PA programs to inform best-practice frameworks and industry capacity building. Future research should use longitudinal and mixed-methods designs to strengthen evidence about facilitators of program reach and engagement.
What is the Contribution of Actual Motor Skill, Fitness, and Physical Activity to Children’s Self-Perception of Motor Competence?
Authors: Barnett Lisa M. , Lubans David R. , Timperio Anna , Salmon Jo , Ridgers Nicola D.
Published: May 2017

This study aimed to examine the contribution of objective measures of physical fitness (musculoskeletal and cardiorespiratory), physical activity, and motor skill to motor perception. A total of 122 children (63 boys) aged 8–11 years were assessed. Independentt-tests assessed sex differences in all variables. Two linear mixed models adjusted for sex and age were performed with perceived object control and locomotor skills (Pictorial Scale of the Perceived Movement Skill Competence for Young Children) as outcomes. Aerobic (multi-stage fitness test) and muscular fitness (long jump, grip strength), moderate-to-vigorous physical activity (ActiGraph accelerometry), movement skill (Test of Gross Motor Development-2), age, and sex were predictors. Boys had higher object control skills (actual and perceived) and fitness. Age (decreasing) and long jump distance (positive) explained 16% of locomotor skill perception variance. Sex (boys) explained 13% of object control skill perception variance. Children’s skill self-perception may be influenced by fitness attributes as these are more evident to them. The fact that girls have lower actual object control competence and fitness than boys suggests girls may be an intervention target.
Y-Balance Test Performance After a Competitive Field Hockey Season: A Pretest-Posttest Study
Authors: Hoch Matthew C. , Welsch Lauren A. , Hartley Emily M. , Powden Cameron J. , Hoch Johanna M.
Published: May 2017

Context: The Y-Balance Test (YBT) is a dynamic balance assessment used as a preseason musculoskeletal screen to determine injury risk. While the YBT has demonstrated excellent test-retest reliability, it is unknown if YBT performance changes following participation in a competitive athletic season. Objective: Determine if a competitive athletic season affects YBT performance in field hockey players. Design: Pretest-posttest. Setting: Laboratory. Participants: 20 NCAA Division I women's field hockey players (age = 19.55 ± 1.30 y; height = 165.10 ± 5.277 cm; mass = 62.62 ± 4.64 kg) from a single team volunteered. Participants had to be free from injury throughout the entire study and participate in all athletic activities. Interventions: Participants completed data collection sessions prior to (preseason) and following the athletic season (postseason). Between data collections, participants competed in the fall competitive field hockey season, which was ~3 months in duration. During data collection, participants completed the YBT bilaterally. Main Outcome Measures: The independent variable was time (preseason, postseason) and the dependent variables were normalized reach distances (anterior, posteromedial, posterolateral, composite) and between-limb symmetry for each reach direction. Differences between preseason and postseason were examined using paired t tests (P ≤ .05) as well as Bland-Altman limits of agreement. Results: 4 players sustained a lower extremity injury during the season and were excluded from analysis. There were no significant differences between preseason and postseason reach distances for any reach directions on either limb (P ≥ .31) or in the between-limb symmetries (P ≥ .52). The limits of agreement analyses determined there was a low mean bias across measurements (≤1.67%); however, the 95% confidence intervals indicated there was high variability within the posterior reach directions over time (±4.75 to ± 14.83%). Conclusion: No changes in YBT performance were identified following a competitive field hockey season in Division I female athletes. However, the variability within the posterior reach directions over time may contribute to the limited use of these directions for injury risk stratification.
Wnt Signaling–Related Osteokines and Transforming Growth Factors Before and After a Single Bout of Plyometric Exercise in Child and Adolescent Females
Authors: Dekker Jennifer , Nelson Katlynne , Kurgan Nigel , Falk Bareket , Josse Andrea , Klentrou Panagiota
Published: May 2017

This study examined resting levels of catabolic and anabolic osteokines related to Wnt signaling and their responses to a single bout of plyometric exercise in child and adolescent females. Fourteen premenarcheal girls [10.5 (1.8) y old] and 12 postmenarcheal adolescent girls [15.0 (1.0) y old] performed a plyometric exercise trial. One resting and 3 postexercise blood samples (5 min, 1 h, and 24 h postexercise) were analyzed for sclerostin, dickkopf-1 (DKK-1), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-β ligand (RANKL), and transforming growth factors (TGF-β1, TGF-β2, and TGF-β3). Premenarcheal girls had significantly higher resting sclerostin, TGF-β1, TGF-β2, and TGF-β3 than the postmenarcheal girls, with no significant time effect or group-by-time interaction. DKK-1 was higher in premenarcheal compared with postmenarcheal girls. There was an overall significant DKK-1 decrease from baseline to 1 h postexercise, which remained lower than baseline 24 h postexercise in both groups. There was neither a significant group effect nor group-by-time interaction in OPG, RANKL, and their ratio. RANKL decreased 5 min postexercise compared with baseline and remained significantly lower from baseline 24 h following the exercise. No changes were observed in OPG. OPG/RANKL ratio was significantly elevated compared with resting values 1 h postexercise. In young females, high-impact exercise induces an overall osteogenic effect through a transitory suppression of catabolic osteokines up to 24 h following exercise.
Pathos and Orchestration in Elite Sport: The Experiences of NCAA DI Student-Athletes
Authors: Raabe Johannes , Readdy Tucker , Zakrajsek Rebecca A.
Published: May 2017

Coaching is characterized by an inherent pathos between the goals coaches hope to accomplish and those that are realized (Jones & Wallace, 2005). Coaches can actively enhance the likelihood of optimal outcomes through orchestration, a process of incremental coping intended to create improvement in performance (Jones & Wallace, 2005). The current study explored to what extent pathos also manifests in the lives of elite athletes and whether they engage in processes consistent with orchestration. Semistructured interviews were conducted with 12 National Collegiate Athletic Association Division I student-athletes. Primarily deductive analysis of the qualitative data provided confirmation for four domains: (a) sources of ambiguity created by coaches, (b) other sources of ambiguity within student-athletes’ experiences, (c) attempted strategies for orchestrating the pathos, and (d) relationships are crucial for navigating the pathos. The findings potentially offer an approach to understanding the challenges athletes face, which allows coaches to more accurately provide assistance.
Efficacy of a Brief Mindfulness Intervention to Prevent Athletic Task Performance Deterioration: A Randomized Controlled Trial
Authors: Perry Joanne E. , Ross Michael , Weinstock Jeremiah , Weaver Terri
Published: May 2017

Research has supported mindfulness as a predictor of athletic success. This study used a parallel trial design to examine the benefit of a brief one-session mindfulness training for performance on an individual, nonpacing, closed skill athletic task (i.e., golf putting). All participants (N = 65) answered questionnaires and engaged in two trials of the putting task. Participants were randomly assigned to an intervention or control group using a simple randomization strategy. Between trials, the intervention group received a mindfulness intervention. Mindfulness intervention included psychoeducation, reflection upon previous sport experiences, an experiential exercise, and putting applications. Repeated-measures ANOVAs demonstrated that the intervention group exhibited more successful outcomes on objective putting performance, flow state experience, and state anxiety (p < .05). Results suggest mindfulness may prevent performance deterioration and could produce psychological benefits after a brief training session.
Clustering Algorithm for Intuitionistic Fuzzy Graphs
Authors: Karunambigai M. G. , Akram Muhammad , Sivasankar S. , Palanivel K.
Published: May 2017

In this paper, we present certain algorithms for clustering the vertices of fuzzy graphs(FGs) and intuitionistic fuzzy graphs(IFGs). These algorithms are based on the edge density of the given graph. We apply the algorithms to practical problems to derive the most prominent cluster among them. We also introduce parameters for intuitionistic fuzzy graphs.
A Dynamic Fuzzy Temporal Clustering for Imprecise Location Streams
Authors: Quero J. Medina , Ruiz Lozano M. D. , Castañeda García J. A. , Rodriguez Molina M. A. , Frias Jamilena D. M.
Published: May 2017

The clustering has provided data analysis in many contexts of Computer Science. It is widely applied in Ambient Intelligence and Ubiquitous Computing for information processing, with geolocation data prominently. In this paper, we introduce a dynamic fuzzy temporal clustering algorithm (DFTC) to detect stays of users in urban environments based on locations from imprecise sensors. Our approach includes fuzzy evaluation of temporal and probabilistic data providing analysis in real time. As results, we have developed a mobile application which integrates the DFTC and detects satisfactorily user stays related to urban commerces from a real environment.
Finding the Shortest Path in Stochastic Graphs Using Learning Automata and Adaptive Stochastic Petri Nets
Authors: Vahidipour S. Mehdi , Meybodi Mohammad Reza , Esnaashari Mehdi
Published: May 2017

Shortest path problem in stochastic graphs has been recently studied in the literature and a number of algorithms has been provided to find it using varieties of learning automata models. However, all these algorithms suffer from two common drawbacks: low speed and lack of a clear termination condition. In this paper, we propose a novel learning automata-based algorithm for this problem which can speed up the process of finding the shortest path using parallelism. For this parallelism, several traverses are initiated, in parallel, from the source node towards the destination node in the graph. During each traverse, required times for traversing from the source node up to any visited node are estimated. The time estimation at each visited node is then given to the learning automaton residing in that node. Using different time estimations provided by different traverses, this learning automaton gradually learns which neighbor of the node is on the shortest path. To set a condition for the termination of the proposed algorithm, we analyze the algorithm using a recently introduced model, Adaptive Stochastic Petri Net (ASPN-LA). The results of this analysis enable us to establish a necessary condition for the termination of the algorithm. To evaluate the performance of the proposed algorithm in comparison to the existing algorithms, we apply it to find the shortest path in six different stochastic graphs. The results of this evaluation indicate that the time required for the proposed algorithm to find the shortest path in all graphs is substantially shorter than that required by similar existing algorithms.
On Simplified Axiomatic Characterizations of (υ σ)-Fuzzy Rough Approximation Operators
Authors: Zhang Hongying , Song Haijuan
Published: May 2017

The axiomatic approach is more appropriate than constructive approach for studying the algebraic structure of rough sets. In this paper, the more simple axiomatic characterizations of (υ σ)-fuzzy rough approximation operators are explored where υ is a residuated implicator and σis its dual implicator. Firstly, we review the existing independent axiomatic sets to characterize various types of υ-lower and σ-upper fuzzy rough approximation operators. Secondly, we present one-axiom characterizations of (υ σ)-fuzzy rough approximation operators constructed by a serial fuzzy relation on two universes. Furthermore, we show that (υ σ)-fuzzy rough approximation operators, corresponding to reexive, symmetric and T-transitive fuzzy relations, can be presented by only two axioms respectively. We conclude the paper by introducing some potential applications and future works.
Numerical solution of differential equations arising in fluid dynamics using Legendre wavelet collocation method
Authors: Shiralashetti S. C. , Deshi A. B.
Published: May 2017

Wavelet analysis is a recently developed mathematical tool for many problems. One of its main attractive features is the ability to accurately represent general functions with small number of adaptively chosen wavelet coefficients. In this paper, the Legendre wavelet collocation method (LWCM) for the numerical solution of differential equations is presented. The proposed method gives better results than the existing ones. Some of the illustrative examples are included to observe the performance of the proposed scheme.
Programmable 2D Arrangements for Element Texture Design
Authors: Loi Hugo , Hurtut Thomas , Vergne Romain , Thollot Joelle
Published: May 2017

This article introduces a programmable method for designing stationary 2D arrangements for element textures, namely textures made of small geometric elements. These textures are ubiquitous in numerous applications of computer-aided illustration. Previous methods, whether they be example-based or layout-based, lack control and can produce a limited range of possible arrangements. Our approach targets technical artists who will design an arrangement by writing a script. These scripts are using three types of operators:
partitioning operators
for defining the broad-scale organization of the arrangement,
mapping operators
for controlling the local organization of elements, and
merging operators
for mixing different arrangements. These operators are designed so as to guarantee a stationary result, meaning that the produced arrangements will always be repetitive. We show that this simple set of operators is sufficient to reach a much broader variety of arrangements than previous methods. Editing the script leads to predictable changes in the synthesized arrangement, which allows an easy iterative design of complex structures. Finally, our operator set is extensible and can be adapted to application-dependent needs.
String Actuated Curved Folded Surfaces
Authors: Kilian Martin , Monszpart Aron , Mitra Niloy J.
Published: May 2017

Curved folded surfaces, given their ability to produce elegant freeform shapes by folding flat sheets etched with curved creases, hold a special place in computational Origami. Artists and designers have proposed a wide variety of different fold patterns to create a range of interesting surfaces. The creative process, design, as well as fabrication is usually only concerned with the static surface that emerges once folding has completed. Folding such patterns, however, is difficult as multiple creases have to be folded simultaneously to obtain a properly folded target shape. We introduce string actuated curved folded surfaces that can be shaped by pulling a network of strings, thus, vastly simplifying the process of creating such surfaces and making the folding motion an integral part of the design. Technically, we solve the problem of which surface points to string together and how to actuate them by locally expressing a desired folding path in the space of isometric shape deformations in terms of novel string actuation modes. We demonstrate the validity of our approach by computing string actuation networks for a range of well-known crease patterns and testing their effectiveness on physical prototypes. All the examples in this article can be downloaded for personal use from http://geometry.cs.ucl.ac.uk/projects/2017/string-actuated/.
Optimizing File Systems with Fine-grained Metadata Journaling on Byte-addressable NVM
Authors: Chen Cheng , Yang Jun , Wei Qingsong , Wang Chundong , Xue Mingdi
Published: May 2017

Journaling file systems have been widely adopted to support applications that demand data consistency. However, we observed that the overhead of journaling can cause up to 48.2% performance drop under certain kinds of workloads. On the other hand, the emerging high-performance, byte-addressable Non-volatile Memory (NVM) has the potential to minimize such overhead by being used as the journal device. The traditional journaling mechanism based on block devices is nevertheless unsuitable for NVM due to the
write amplification
of metadata journal we observed. In this article, we propose a fine-grained metadata journal mechanism to fully utilize the low-latency byte-addressable NVM so that the overhead of journaling can be significantly reduced. Based on the observation that conventional block-based metadata journal contains up to 90% clean metadata that is unnecessary to be journalled, we design a fine-grained journal format for byte-addressable NVM which contains only modified metadata. Moreover, we redesign the process of transaction committing, checkpointing, and recovery in journaling file systems utilizing the new journal format. Therefore, thanks to the reduced amount of ordered writes for journals, the overhead of journaling can be reduced without compromising the file system consistency. To evaluate our fine-grained metadata journaling mechanism, we have implemented a journaling file system prototype based on Ext4 and JBD2 in Linux. Experimental results show that our NVM-based fine-grained metadata journaling is up to 15.8 × faster than the traditional approach under FileBench workloads.
Design and Analysis of STTRAM-Based Ternary Content Addressable Memory Cell
Authors: Govindaraj Rekha , Ghosh Swaroop
Published: May 2017

Content Addressable Memory (CAM) is widely used in applications where searching a specific pattern of data is a major operation. Conventional CAMs suffer from area, power, and speed limitations. We propose Spin-Torque Transfer RAM--based Ternary CAM (TCAM) cells. The proposed NOR-type TCAM cell has a 62.5% (33%) reduction in number of transistor compared to conventional CMOS TCAMs (spintronic TCAMs). We analyzed the sense margin of the proposed TCAM with respect to 16-, 32-, 64-, 128-, and 256-bit word sizes in 22nm predictive technology. Simulations indicated a reliable sense margin of 50mV even at 0.7V supply voltage for 256-bits word. We also explored a selective threshold voltage modulation of transistors to improve the sense margin and tolerate process and voltage variations. The worst-case search latency and sense margin of 256-bit TCAM is found to be 263ps and 220mV, respectively, at 1V supply voltage. The average search power consumed is 13mW, and the search energy is 4.7fJ/bit search. The write time is 4ns, and the write energy is 0.69pJ/bit. We leverage the NOR-type TCAM design to realize a 9T-2 Magnetic Tunnel Junctions NAND-type TCAM cell that has 43.75% less number of transistors than the conventional CMOS TCAM cell. A NAND-type cell can support up to 64-bit words with a maximum sense margin of up to 33mV. We compare the performance metrics of NOR- and NAND-type TCAM cells with other TCAMs in the literature.
Quantum Circuit Synthesis Targeting to Improve One-Way Quantum Computation Pattern Cost Metrics
Authors: Houshmand Mahboobeh , Sedighi Mehdi , Zamani Morteza Saheb , Marjoei Kourosh
Published: May 2017

One-way quantum computation (1WQC) is a model of universal quantum computations in which a specific highly entangled state called acluster stateallows for quantum computation by single-qubit measurements. The needed computations in this model are organized as measurement patterns. The traditional approach to obtain a measurement pattern is by translating a quantum circuit that solely consists of CZ andJ(α) gates into the corresponding measurement patterns and then performing some optimizations by using techniques proposed for the 1WQC model. However, in these cases, the input of the problem is a quantum circuit, not an arbitrary unitary matrix. Therefore, in this article, we focus on the first phase—that is, decomposing a unitary matrix into CZ andJ(α) gates. Two well-known quantum circuit synthesis methods, namely cosine-sine decomposition and quantum Shannon decomposition are considered and then adapted for a library of gates containing CZ andJ(α), equipped with optimizations. By exploring the solution space of the combinations of these two methods in a bottom-up approach of dynamic programming, a multiobjective quantum circuit synthesis method is proposed that generates a set of quantum circuits. This approach attempts to simultaneously improve the measurement pattern cost metrics after the translation from this set of quantum circuits.
Boundary Element Octahedral Fields in Volumes
Authors: Solomon Justin , Vaxman Amir , Bommes David
Published: May 2017

The computation of smooth fields of orthogonal directions within a volume is a critical step in hexahedral mesh generation, used to guide placement of edges and singularities. While this problem shares high-level structure with surface-based frame field problems, critical aspects are lost when extending to volumes, while new structure from the flat Euclidean metric emerges. Taking these considerations into account, this article presents an algorithm for computing such “octahedral” fields. Unlike existing approaches, our formulation achieves
infinite
resolution in the interior of the volume via the boundary element method (BEM), continuously assigning frames to points in the interior from only a triangle mesh discretization of the boundary. The end result is an orthogonal direction field that can be sampled anywhere inside the mesh, with smooth variation and singular structure in the interior, even with a coarse boundary. We illustrate our computed frames on a number of challenging test geometries. Since the octahedral frame field problem is relatively new, we also contribute a thorough discussion of theoretical and practical challenges unique to this problem.
ExaPlan
Authors: Iliadis Ilias , Jelitto Jens , Kim Yusik , Sarafijanovic Slavisa , Venkatesan Vinodh
Published: May 2017

Multi-tiered storage, where each tier consists of one type of storage device (e.g., SSD, HDD, or disk arrays), is a commonly used approach to achieve both high performance and cost efficiency in large-scale systems that need to store data with vastly different access characteristics. By aligning the access characteristics of the data, either fixed-sized extents or variable-sized files, to the characteristics of the storage devices, a higher performance can be achieved for any given cost. This article presents ExaPlan, a method to determine both the data-to-tier assignment and the number of devices in each tier that minimize the system’s mean response time for a given budget and workload. In contrast to other methods that constrain or minimize the system load, ExaPlan directly minimizes the system’s mean response time estimated by a queueing model. Minimizing the mean response time is typically intractable as the resulting optimization problem is both nonconvex and combinatorial in nature. ExaPlan circumvents this intractability by introducing a parameterized data placement approach that makes it a highly scalable method that can be easily applied to exascale systems. Through experiments that use parameters from real-world storage systems, such as CERN and LOFAR, it is demonstrated that ExaPlan provides solutions that yield lower mean response times than previous works. It supports standalone SSDs and HDDs as well as disk arrays as storage tiers, and although it uses a static workload representation, we provide empirical evidence that underlying dynamic workloads have invariant properties that can be deemed static for the purpose of provisioning a storage system. ExaPlan is also effective as a load-balancing tool used for placing data across devices within a tier, resulting in an up to 3.6-fold reduction of response time compared with a traditional load-balancing algorithm, such as the Longest Processing Time heuristic.