bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Successive Badminton Matches on Muscle Strength, Power, and Body-Fluid Balance in Elite Players
Authors: Abian-Vicen Javier , Castanedo Adrián , Abian Pablo , Gonzalez-Millan Cristina , Salinero Juan José , Coso Juan Del
Published: June 2014

The aim was to analyze the influence of competitive round on muscle strength, body-fluid balance, and renal function in elite badminton players during a real competition. Body mass, jump height during a countermovement jump, handgrip force, and urine samples were obtained from 13 elite badminton players (6 men and 7 women) before and after the 2nd-round and quarterfinal matches of the national Spanish badminton championship. Sweat rate was determined by using prematch-to-postmatch body-mass change and by weighing individually labeled fluid bottles. Sweat rates were 1.04 ± 0.62 and 0.98 ± 0.43 L/h, while rehydration rate was 0.69 ± 0.26 and 0.91 ± 0.52 L/h for the 2nd round and quarterfinals, respectively. Thus, dehydration was 0.47% ± 1.03% after the 2nd round and 0.23% ± 0.43% after the quarterfinals. There were no differences in prematch-to-postmatch jump height, but jump height was reduced from 37.51 ± 8.83 cm after the 2nd-round game to 34.82 ± 7.37 cm after the quarterfinals (P < .05). No significant differences were found in handgrip force when comparing prepost matches or rounds, although there were significant differences between dominant and nondominant hands (P < .05). The succession of rounds caused the appearance of proteinuria, hematuria, glycosuria, and higher nitrite and ketone concentrations in urine. Rehydration patterns during a real badminton competition were effective to prevent dehydration. A badminton match did not affect jump height or handgrip force, but jump height was progressively reduced by the competitive round. Badminton players’ renal responses reflected diminished renal flux due to the high-intensity nature of this racket sport.
Effect of Age, Anthropometry, and Distance in Stroke Parameters of Young Swimmers
Authors: Mezzaroba Paulo V. , Machado Fabiana A.
Published: June 2014

This study aimed to determine the influence of age, anthropometry, and distance on stroke parameters of 10- to 17-y-old swimmers. Forty-six male swimmers were divided into 4 chronological age groups. Anthropometry and sexual maturity were assessed, and maximal efforts of 100, 200, and 400 m using front-crawl style were performed to determine stroke rate (SR), length (SL), and index (SI). Multiple linear regression, 1-way, and mixed ANOVA for repeated measures were used for statistical analyses. There was significant effect of distance for all stroke parameters (P < .001) and an age effect only for SL and SI (P < .001). Post hoc showed that the 10- to 17-year-old group significantly reduced SR with increasing distance (effect size –0.8 to –1.5 comparing 100, 200, and 400 m) but were not effective in offsetting this adaptation with increased SL, especially from 200- to 400-m distance, at which no group made both adjustments, highlighting the decreased efficiency with significant SI reduction (effect size –0.2 to –0.4 comparing 100, 200, and 400 m). Considering all stroke parameters, the performances were almost 100% explained, but SI itself could explain around 90% of the performance; furthermore, limb length contributed to explain all stroke parameter, and SI was the variable best predicted (around 75%) by anthropometrical (upper limbs and height) and descriptive variables (age and y of systematic training).Thus, distinct effects of distance and advancing age were found during childhood and adolescence on stroke parameters, and SI was highlighted as the best predictor of 100-, 200-, and 400-m maximal performances.
Physiological and Performance Responses to a Training Camp in the Heat in Professional Australian Football Players
Authors: Racinais Sebastien , Buchheit Martin , Bilsborough Johann , Bourdon Pitre C. , Cordy Justin , Coutts Aaron J.
Published: June 2014

Purpose:

To examine the physiological and performance responses to a heat-acclimatization camp in highly trained professional team-sport athletes.

Methods:

Eighteen male Australian Rules Football players trained for 2 wk in hot ambient conditions (31–33°C, humidity 34–50%). Players performed a laboratory-based heat-response test (24-min walk + 24 min seated; 44°C), a YoYo Intermittent Recovery Level 2 Test (YoYoIR2; indoor, temperate environment, 23°C) and standardized training drills (STD; outdoor, hot environment, 32°C) at the beginning and end of the camp.

Results:

The heat-response test showed partial heat acclimatization (eg, a decrease in skin temperature, heart rate, and sweat sodium concentration, P < .05). In addition, plasma volume (PV, CO rebreathing, +2.68 [0.83; 4.53] mL/kg) and distance covered during both the YoYoIR2 (+311 [260; 361] m) and the STD (+45.6 [13.9; 77.4] m) increased postcamp (P < .01). None of the performance changes showed clear correlations with PV changes (r < .24), but the improvements in running STD distance in hot environment were correlated with changes in hematocrit during the heat-response test (r = –.52, 90%CI [–.77; –.12]). There was no clear correlation between the performance improvements in temperate and hot ambient conditions (r < .26).

Conclusion:

Running performance in both hot and temperate environments was improved after a football training camp in hot ambient conditions that stimulated heat acclimatization. However, physiological and performance responses were highly individual, and the absence of correlations between physical-performance improvements in hot and temperate environments suggests that their physiological basis might differ.
Second Ventilatory Threshold From Heart-Rate Variability: Valid When the Upper Body Is Involved?
Authors: Mourot Laurent , Fabre Nicolas , Savoldelli Aldo , Schena Federico
Published: June 2014

To determine the most accurate method based on spectral analysis of heart-rate variability (SA-HRV) during an incremental and continuous maximal test involving the upper body, the authors tested 4 different methods to obtain the heart rate (HR) at the second ventilatory threshold (VT2). Sixteen ski mountaineers (mean ± SD; age 25 ± 3 y, height 177 ± 8 cm, mass 69 ± 10 kg) performed a roller-ski test on a treadmill. Respiratory variables and HR were continuously recorded, and the 4 SA-HRV methods were compared with the gas-exchange method through Bland and Altman analyses. The best method was the one based on a time-varying spectral analysis with high frequency ranging from 0.15 Hz to a cutoff point relative to the individual’s respiratory sinus arrhythmia. The HR values were significantly correlated (r2 = .903), with a mean HR difference with the respiratory method of 0.1 ± 3.0 beats/min and low limits of agreements (around –6/+6 beats/min). The 3 other methods led to larger errors and lower agreements (up to 5 beats/min and around –23/+20 beats/min). It is possible to accurately determine VT2 with an HR monitor during an incremental test involving the upper body if the appropriate HRV method is used.
The Influence of Upper-Body Strength on Flat-Water Sprint Kayak Performance in Elite Athletes
Authors: McKean Mark R. , Burkett Brendan J.
Published: June 2014

Dry-land strength training is a fundamental component for elite kayak performance. The aims of this research were 3-fold: 1st, to determine the relationship between performance time and strength scores for elite kayakers; 2nd, to identify how strength changes (gains or losses) over 3 training y relate with changes in performance time for elite kayakers; and 3rd, to compare the progression in performance times for elite athletes with the top 3 performers from the national championships. The performance data for 15 elite male and 10 elite female kayakers were collected over 2 y. This group was reduced to 9 men and 8 women in the 3rd and final year. There were direct and significant correlations between strength scores and performance times across the 3 y. Bench-press 1RM increased by 34.8% for men and 42.3% for women. Over the 3 seasons, mean 1000-m time decreased by approximately 4.8%, 500-m times decreased by 7.3% (women), and 200-m times decreased by 9.1%. The women’s 500-m changed from 11.9% difference from medalists to within 1.1% during the 3 y. During the 3 y of this study a change in 1-repetitionmaximum (1RM) bench press of 13% for men and 6.5% in women coincided with a change in performance times of 1%. For 1RM pull-up a change of 10% in men and 2.3% in women coincided with a change in performance times of 1%.
Variability in Power Output During Cycling in International Olympic-Distance Triathlon
Authors: Etxebarria Naroa , D’Auria Shaun , Anson Judith M. , Pyne David B. , Ferguson Richard A.
Published: June 2014

Purpose:

The patterns of power output in the ~1-h cycle section of Olympic-distance triathlon races are not well documented. Here the authors establish a typical cycling-race profile derived from several International Triathlon Union elite-level draftinglegal triathlon races.

Methods:

The authors collated 12 different race power profiles from elite male triathletes (N = 5, age 25 ± 5 y, body mass 65.5 ± 5.6 kg; mean ± SD) during 7 international races. Power output was recorded using SRM cranks and analyzed with proprietary software.

Results:

The mean power output was 252 ± 33 W, or 3.9 ± 0.5 W/kg in relative terms, with a coefficient of variation of 71% ± 13%. Normalized power (power output an athlete could sustain if intensity were maintained constant without any variability) for the entire cycle section was 291 ± 29 W, or 40 ± 13 W higher than the actual mean power output. There were 34 ± 14 peaks of power output above 600 W and ~18% time spent at >100% of maximal aerobic power.

Conclusion:

Cycling during Olympic-distance triathlon, characterized by frequent and large power variations including repeat supramaximal efforts, equates to a higher workload than cycling at constant power.
The Back Squat and the Power Clean: Elicitation of Different Degrees of Potentiation
Authors: Seitz Laurent B. , Trajano Gabriel S. , Haff G. Gregory
Published: June 2014

Purpose:

To compare the acute effects of back squats and power cleans on sprint performance.

Methods:

Thirteen elite junior rugby league players performed 20-m linear sprints before and 7 min after 2 different conditioning activities or 1 control condition. The conditioning activities included 1 set of 3 back squats or power cleans at 90% 1-repetition maximum. A 2 × 2 repeated-measures ANOVA was used to compare preconditioning and postconditioning changes in sprint performance.

Results:

Both the back-squat and power-clean conditioning activities demonstrated a potentiation effect as indicated by improved sprint time (back squat: P = .001, ES = –0.66; power cleans: P = .001, ES = –0.92), velocity (back squat: P = .001, ES = 0.63; power cleans: P = .001, ES = 0.84), and average acceleration over 20 m (back squat: P = .001, ES = 0.70; power cleans: P = .001, ES = 1.00). No potentiation effect was observed after the control condition. Overall, the power clean induced a greater improvement in sprint time (P = .042, ES = 0.83), velocity (P = .047, ES = 1.17), and average acceleration (P = .05, ES = 0.87) than the back squat.

Conclusions:

Back-squat and power-clean conditioning activities both induced improvements in sprint performance when included as part of a potentiation protocol. However, the magnitude of improvement was greater after the power cleans. From a practical perspective, strength and conditioning coaches should consider using power cleans rather than back squats to maximize the performance effects of potentiation complexes targeting the development of sprint performance.
Determinants of Performance in a New Test of Planned Agility for Young Elite Basketball Players
Authors: Delextrat Anne , Grosgeorge Bernard , Bieuzen Francois
Published: June 2014

Purpose:

To investigate the reliability and determinants of performance in a new test of planned agility in elite junior basketball players.

Methods:

Seventeen female (15.1 ± 0.4 y, 176.9 ± 11.2 cm, 65.7 ± 10.9 kg) and 42 male (14.9 ± 0.4 y, 193.7 ± 8.1 cm, 79.0 ± 12.0 kg) elite junior basketball players performed 5 fitness tests presented in a random order, including a 20-m sprint, a planned-agility test, a triple bilateral horizontal countermovement jump, and 2 triple unilateral horizontal countermovement jumps (with each leg separately). The novelty of the planned-agility test is that it included both offensive and defensive movements. The determinants of planned agility were assessed by a stepwise-regression analysis, and the reliability of the new test was evaluated by the intraclass correlation coefficient and the typical error of measurement.

Results:

The main results show good reliability of the new test of planned agility. In addition, the determinants of planned-agility performance were different between genders, with sprint performance explaining 74.8% of the variance for girls, while unilateral jump performance and body mass were the most important for boys, accounting for 24.0% and 8.9% of the variance, respectively, in planned agility.

Conclusions:

These results highlight a gender effect on the determinants of planned-agility performance in young elite basketball players and suggest that straight-line sprint and unilateral horizontal tests must be implemented to test elite junior players.
Factors Affecting Physical Activity in Ecuadorian Adolescents: A Focus Group Study
Authors: Van Royen Kathleen , Verstraeten Roosmarijn , Andrade Susana , Ochoa-Avilés Angélica , Donoso Silvana , Maes Lea , Kolsteren Patrick
Published: June 2014

Background:

Physical inactivity levels are increasingly prevalent among Ecuadorian adolescents. School-based interventions can be potentially effective in promoting physical activity but must be informed by cultural-specific factors.

Methods:

Twelve focus groups were carried out with adolescents (n = 80) in rural and urban Ecuador to identify factors influencing physical activity. In addition, 4 focus group discussions with parents (n = 32) and 4 with school staff (n = 32) were conducted. Individual and environmental factors were questioned using the ‘Attitude, Social influences and Self-efficacy’ model and the socioecological model as theoretical frameworks.

Results:

Factors influencing physical activity varied between groups. In the rural area farming and norms for girls impeded leisure-time physical activity, whereas urban groups emphasized traffic and crime concerns. Groups from a low socioeconomic status more frequently mentioned a fear of injuries and financial constraints. Several factors were common for all groups including preferences for sedentary activities, poor knowledge, time constraints and laziness, as well as a lack of opportunities at home and school, unsupportive parental rules and lack of role models.

Conclusion:

A conceptual framework including the identified factors emerged to inform the design of a cultural-sensitive school-based intervention to improve physical activity among Ecuadorian adolescents. Future interventions should be tailored to each setting.
A Mixed-Method Approach to Exploring the Motives of Sport-Related Mobile Applications Among College Students
Authors: Kang Sun J. , Ha Jae-Pil , Hambrick Marion E.
Published: June 2014

The popularity of smartphones has led to the creation of sport-related mobile applications in the areas of games, fitness, information, and events for sport consumers. The main purpose of this study was to examine why college students use sport-related mobile applications and what benefits they received from their usage. The study employed the Motivation Scale for Sport Online Consumption and the Technology Acceptance Model to understand this usage in more detail. Using a mixed-method approach, the study revealed that college students identified fanship, convenience, and information as primary motives for using their sport-related mobile applications. For college students who are sport fans, supporting their fanship through these applications represents an important aspect of their lifestyle. Sport managers and sport application developers will benefit from understanding users’ intentions and motives as the market for sport-related applications continues to grow.
Kinesio Taping and Jump Performance in Elite Female Track and Field Athletes
Authors: Schiffer Thorsten , Möllinger Anne , Sperlich Billy , Memmert Daniel
Published: June 2014

Context:

The application of kinesio tape (KT) to lower-extremity muscles as an ergogenic aid to improve muscle-strength-related parameters such as jumping is controversial.

Objective:

To test the hypothesis that the application of KT enhances the jumping performance of healthy uninjured elite female track and field athletes.

Design:

A double 1-legged jump test was performed before and after the application of blue K-Active tape without traction on the maximally stretched gastrocnemius, hamstrings, rectus femoris, and iliopsoas muscles according to the generally accepted technique.

Participants:

18 German elite female track and field athletes (age 21 ± 2 y, height 172 ± 4 cm, body mass 62 ± 5 kg, active time in their sport 13 ± 4 y).

Results:

Factorial analysis of variance with repeated measures (ANOVA, Bonferroni) revealed no significant differences in jumping performance between the tests (P > .05, d = 0.26).

Conclusions:

These findings suggest that the application of KT has no influence on jumping performance in healthy, uninjured female elite athletes. The authors do not recommend the use of KT for the purpose of improving jump performance.
Real-Time Biofeedback to Target Risk of Anterior Cruciate Ligament Injury: A Technical Report for Injury Prevention and Rehabilitation
Authors: Ford Kevin R. , DiCesare Christopher A. , Myer Gregory D. , Hewett Timothy E.
Published: June 2014

Context: Biofeedback training enables an athlete to alter biomechanical and physiological function by receiving biomechanical and physiological data concurrent with or immediately after a task. Objective: To compare the effects of 2 different modes of real-time biofeedback focused on reducing risk factors related to anterior cruciate ligament injury. Design: Randomized crossover study design. Setting: Biomechanics laboratory and sports medicine center. Participants: Female high school soccer players (age 14.8 ± 1.0 y, height 162.6 ± 6.8 cm, mass 55.9 ± 7.0 kg; n = 4). Intervention: A battery of kinetic- or kinematic-based real-time biofeedback during repetitive double-leg squats. Main Outcome Measures: Baseline and posttraining drop vertical jumps were collected to determine if either feedback method improved high injury risk landing mechanics. Results: Maximum knee abduction moment and angle during the landing was significantly decreased after kinetic-focused biofeedback (P = .04). The reduced knee abduction moment during the drop vertical jumps after kinematic-focused biofeedback was not different (P = .2). Maximum knee abduction angle was significantly decreased after kinetic biofeedback (P < .01) but only showed a trend toward reduction after kinematic biofeedback (P = .08). Conclusions: The innovative biofeedback employed in the current study reduced knee abduction load and posture from baseline to posttraining during a drop vertical jump.
Cerebral hypoperfusion secondary to radiation arteritis presenting with recurrent syncope
Authors: Bashar Khalid , McHugh Seamus , Burke Paul , Kavanagh Eamon
Published: June 2014

Radiation arteritis can lead to significant extracranial carotid artery stenosis, affecting the circle of Willis. Cerebral hypoperfusion due to arterial insufficiency is often considered as a differential diagnosis in cases of syncope but rarely proven. We present a case of a 61-year-old man with repeated episodes of syncope-negative cardiac investigations. He had a history of cervical radiation therapy for tonsillar squamous cell carcinoma 15 years previously. Carotid duplex revealed bilateral carotid occlusive disease. MR angiography showed severe multilevel extracranial carotid stenosis bilaterally with occluded left vertebral artery. A diagnosis of cerebral hypoperfusion was performed following single-photon emission CT scan. The patient underwent a left subclavian to carotid bypass, which alleviated his symptoms.
Breast augmentation with an unknown substance
Authors: Ebrahim Lamya , Morrison David , Kop Alan , Taylor Donna
Published: June 2014

Before the widespread use of silicone implants various foreign substances were injected directly into the breasts. The nature of these materials sometimes remains unknown and can cause various complications requiring surgical intervention. Preoperative diagnostic imaging can help characterise the type and distribution of the injected material, thereby assisting in making decisions regarding treatment. We report a case of breast augmentation with an unknown substance, aiming to highlight some imaging characteristics of different breast augmentation substances.
Comparison of bilateral and unilateral contractions between swimmers and nonathletes during leg press and hand grip exercises
Authors: MacDonald Monica , Losier Danielle , Chester Victoria L. , Kuruganti Usha
Published: June 2014

The bilateral limb deficit (BLD) is defined as the reduction in force production during bilateral compared with summed unilateral contractions of homologous muscles. The underlying mechanism for the BLD has been elusive to determine. The purpose of this study was to examine the presence of the BLD during maximal isometric leg press and handgrip exercises in female swimmers (n = 9, mean age = 20.1 ± 1.3 years) and nonathletes (n = 9, mean age = 21.7 ± 1.3 years) to gain further insight into this phenomenon. Force and electromyography (EMG) measures were collected from participants under bilateral and unilateral conditions for handgrip and leg press exercises. Bilateral limb ratios (BLR) were calculated for swimmers (BLRS) and nonathletes (BLRNA). A deficit was found for swimmers and nonathletes in leg force (BLRS = 79.84% ± 13.09% and BLRNA = 81.44% ± 19.23%) and leg EMG (BLRS = 88.45% ± 15.41% and BLRNA = 94.66% ± 13.62%); however, no BLD was seen in hand force (BLRS = 98.30% ± 11.21% and BLRNA = 95.91% ± 11.04%) and hand EMG (BLRS = 102.42% ± 11.20% and BLRNA = 103.30% ± 16.50%). Furthermore, no significant differences were found between groups for leg force, leg EMG, hand force, and hand EMG. In conclusion, a BLD was detected for both groups during bilateral isometric leg press. This suggests that while the BLD may be affected by neural influences, there may other factors involved such as postural stability requirements to perform the exercise.
Testing for dual impacts of contaminants and parasites on hosts: the importance of skew
Authors: Morrill A. , Provencher J.F. , Forbes M.R.
Published: June 2014

A review of recent studies published over a 23-year timespan (1990–2012) showed rapidly increasing interest in exploring how environmental contaminants and parasitism might influence each other and (or) interact to affect host health. Those experimental and observational studies fall into three broad categories (comparative studies of the possible influence of each factor on the other, correlative studies between contaminants and parasitism, and studies on relative bioaccumulation of contaminants by parasites versus their hosts). Despite the exponential increase in relevant studies, little attention has been paid to how contaminants and parasitism should co-occur among individuals within host populations and (or) how the nature of co-distributions should be incorporated into study designs and analyses. Null expectations of co-distributions between contaminants and parasitism can be derived from underlying distributions of each factor. Using a subset of studies, we found contaminant distributions showed positive skew in about one third of cases testing for correlations between contaminant concentrations and parasitism among hosts. We show such skew is expected for theoretical reasons. We used this information to guide simulations wherein the oft-cited negative binomial distribution of parasitism (also supported by theory) was combined with both log-normal (skewed) and normal distributions of contaminants to generate expected null co-distributions. Simulations demonstrated an increasingly concave (or L-shaped) co-distribution with increasing contaminant positive skew: proportionately more individuals experience low levels of each factor while few to none experienced high contaminant and high parasite burdens simultaneously. Our results have the following implications: they call into question experimental studies exposing specimens to parasites and pollutants at levels higher than, or even equal to, observed averages, and they provide a framework for exploring how individual-based effects might scale up into effects at the population level. Potential improvements to study designs and (or) statistical tests are offered that recognize the need to understand the underlying distributions of both contaminants and parasitism and the degree to which one can infer host population effects.
SENSOR (GROUP FEATURE) SELECTION WITH CONTROLLED REDUNDANCY IN A CONNECTIONIST FRAMEWORK
Authors: CHAKRABORTY RUDRASIS , LIN CHIN-TENG , PAL NIKHIL R.
Published: June 2014

For many applications, to reduce the processing time and the cost of decision making, we need to reduce the number of sensors, where each sensor produces a set of features. This sensor selection problem is a generalized feature selection problem. Here, we first present a sensor (group-feature) selection scheme based on Multi-Layered Perceptron Networks. This scheme sometimes selects redundant groups of features. So, we propose a selection scheme which can control the level of redundancy between the selected groups. The idea is general and can be used with any learning scheme. We have demonstrated the effectiveness of our scheme on several data sets. In this context, we define different measures of sensor dependency (dependency between groups of features). We have also presented an alternative learning scheme which is more effective than our old scheme. The proposed scheme is also adapted to radial basis function (RBS) network. The advantages of our scheme are threefold. It looks at all the groups together and hence can exploit nonlinear interaction between groups, if any. Our scheme can simultaneously select useful groups as well as learn the underlying system. The level of redundancy among groups can also be controlled.
Multifractal detrended fluctuation analysis of pseudorapidity and azimuthal distribution of pions emitted in high energy nuclear collisions
Authors: Dutta Srimonti , Ghosh Dipak , Chatterjee Sucharita
Published: June 2014

In this paper multifractal analysis of fluctuation pattern of pions emitted in 32 S-AgBr and 16 O-AgBr interactions at 200 GeV and 60 GeV, respectively, is performed in the framework of multifractal detrended fluctuation analysis (MFDFA). The pseudorapidity and azimuthal distributions exhibit multifractal scaling properties at both energies. The variation of multifractal width with energy is also studied. The study reveals a dependence of multifractal width on energy in pseudorapidity space while no such dependence is observed in azimuthal space.
Unitarity constraints for Yukawa couplings in the two-Higgs-doublet model type III
Authors: Castillo Andrés , Diaz Rodolfo A. , Morales Jhon
Published: June 2014

Unitarity constraints for Yukawa couplings are considered in the Two-Higgs-Doublet Model type III, by using a general expansion in partial waves for fermionic scattering processes. Constraints over general Flavor Changing Neutral Currents are found from that systematic, wherein such bounds compete with those coming from Lagrangian perturbativity requirement but are weaker than those imposed from phenomenological processes and precision tests. Nevertheless, for bounds based on unitarity, the number of assumptions is the lowest among phenomenological and theoretical limits. Indeed, these new theoretical constraints are independent of scalar masses or mixing angles for this extended Higgs sector, making them less model dependent.
Further investigation on phase transitions of Born–Infeld AdS black holes
Authors: Mo Jie-Xiong , Li Gu-Qiang , Liu Wen-Biao
Published: June 2014

In this paper, we further investigate the phase transitions of Born–Infeld AdS black holes in canonical ensemble. We take a different approach to investigate in detail the impact of the choice of parameters. Some interesting phase transition phenomena which has been ignored before are discovered. To examine the phase structure we find, we carry out the standard analysis of the behavior of free energy. We also apply the framework of geometrothermodynamics into Born–Infeld AdS black holes. It is shown that the Legendre invariant thermodynamic scalar curvature diverges exactly where the specific heat at constant charge diverges, which confirms the correctness of the phase structure we find. It is worth noting that although the phase structure shares similarity with RN-AdS black hole, it also has its unique characteristics due to influence of Born–Infeld electrodynamics.
Activation instanton in real-time formalism
Authors: Kolokolov I. V. , Trung Nguyen Thanh
Published: June 2014

In this paper, we study the dynamics of the activation of a Brownian particle using the path integral formalism in real time. Along with the construction of the saddle-point (instanton) solutions, we develop the formalism allowing to calculate the effect of the fluctuations near this solution in detail. In particular, it is shown that there is a soft mode for which the integration is not Gaussian and just this mode is responsible for the finite probability flux.
Optical transmission through generalized third-order Fibonacci multilayers
Authors: Hu Xubo , Yang Xiangbo , Liu Songhao
Published: June 2014

In this paper, by means of three kinds of methods we study the transmission properties of the light through the quasiperiodic multilayers vertically following the generalized third-order Fibonacci (GTOF) sequences. By means of the decomposition–substitution (DS) method we predict that the GTOF systems possess an interesting four-cycle transmissive characteristic at the central wavelength. Based on the electromagnetic wave theory, we then deduce the formulae of propagation matrices and transmission coefficients analytically at the central wavelength and obtain the numerical simulation results at the same time. The results obtained by three kinds of methods accord with each other and three kinds of methods are complementary. The cyclic transmissive characteristics may be useful for the designing of some optical memories, optical logical gates, and other optical controlling devices.
Fabrication and magnetic properties of ferromagnetic Co50Fe50 nanorings
Authors: Guo Zhengang , Qiu Hongmei , Cao Lipeng
Published: June 2014

In this paper, ferromagnetic Co 50 Fe 50 nanorings were fabricated by template-assisted sputtering deposition. The obtained Co 50 Fe 50 nanorings have a good dimensional uniformity, with outer diameter of 360 nm, width of 50 nm and thickness of 40 nm. The magnetic properties of Co 50 Fe 50 nanorings were investigated by micromagnetic simulations and vibrating sample magnetometer. We observed two parallel magnetic switching processes in the micromagnetic simulations of nanorings, the vortex formation process and onion rotation process, respectively. Quantitative analysis on the basis of experimental results indicates that 43.7% of the Co 50 Fe 50 nanorings undergo the vortex formation process and others undergo the onion rotation process.
New approach to pancake vortices interaction with nanosized defects in HTc superconductors
Authors: Sosnowski J.
Published: June 2014

In this paper, an elaborated new theoretical model of the interaction of pancake-type vortices with nanosized defects is presented based on the energy gain analysis of the captured pancake vortices in nanosized defects in multilayered HTc superconductors. Current–voltage characteristics have been calculated in static and dynamic cases and compared with experimental data. Dynamical anomalies have been then predicted based on the solution of magnetic diffusion equation, which also well correspond to our previous experimental data.
Thermoluminescence study on TlGaSSe layered single crystals
Authors: Delice Serdar , Gasanly Nizami M.
Published: June 2014

The defect centers in TlGaSSe single crystals have been investigated by performing thermoluminescence (TL) measurements with various heating rates between 0.5 K/s and 1.0 K/s in the temperature range of 10–180 K. The TL spectra, with peak maximum temperatures at 39 K and 131 K, revealed the existences of two defect levels. Curve fitting, initial rise and peak shape methods were used to determine the activation energies of two defect centers. The experimental results also showed that the trapping process was dominated by second-order kinetics for the trap related with low temperature peak while the general order (mixed order) kinetics was dominant for the trap donated to high temperature peak. Furthermore, heating rate dependences and traps distributions were studied for two defect centers separately. Thermal quenching effect dominates the behavior of these defects as the heating rate is increased. Also, quasi-continuous distributions were established with the increase of the activation energies from 16 meV to 27 meV and from 97 meV to 146 meV for the traps associated with the peaks observed at low and high temperatures, respectively.
Wide-band perfect optical absorption and photo-thermal effect for three-tier nanogate
Authors: Cai G. W. , Ding P. , Wang J. Q. , Liang E. J.
Published: June 2014

This paper designed a perfect optical absorber based on three-tier gate nanostructure, which shows a wide-band perfect absorption in the wavelength range of 200–560 nm as a transverse wave incidents to the nanostructure with the incident angle 35°< θ< 65°. When θ = 45°, a wide absorption band with the absorption rate more than 94% is observed, with the maximum of absorption rate reaching 99.3% at the wavelength of 430 nm. We also analyze the thermal characteristics of the perfect absorber. The band ranging from 560 nm to 1200 nm presents an increasing absorption rate with the increase of temperature. The calculation results of multi-physics analysis indicate that different cooling method causes different temperature distribution for the perfect absorber. This three-tier gate perfect absorber may find applications on broadband visible detectors, microbolometer and thermal imaging.
UNCONSTRAINED IRIS AUTHENTICATION THROUGH FUSION OF RGB CHANNEL INFORMATION
Authors: POORNIMA S. , SUBRAMANIAN S.
Published: June 2014

The unique iris pattern of each human eye is complex, but easily be scanned or captured by a camera. However, the high cost infrared iris scanners used for acquisition causes inconvenience to users by distance related constraints. This restricts its widespread use in real-time applications such as airports and banks. The images captured by cameras under visible wavelength are obstructed by the presence of reflections and shadows which requires additional attention. The main objective of this paper is to propose a secure biometric iris authentication system by fusion of RGB channel information from the real-time data captured under visible wavelength and varying light conditions. The proposed system is adapted to a real-time noisy iris dataset. The effectiveness of this proposed system was tested on two different color iris datasets, namely, a public database UBIRISv1 and a newly created database SSNDS which contains images captured with any digital/mobile camera of minimum 5MP under unconstrained environments. This system supports the cross sensor acquisition and successful iris segmentation from these unconstrained inputs. The features from each channel are extracted using log Gabor filter and a matching is performed using hamming distance based on two thresholds (inter and intra class variations). The performance quality of the proposed biometric system leads to the feasibility of a new cost-effective approach for any real-time application, which requires authentication to ensure quality service, enhance security, eliminate fraud, and maximize effectiveness.
ILLUMINATION PROCESSING IN FACE RECOGNITION
Authors: CHEN ZHENXUE , LIU CHENGYUN , CHANG FALIANG , HAN XUZHEN , WANG KAIFANG
Published: June 2014

Changes in light intensity and angle present a major challenge to the creation of reliable face recognition systems. The existence of bright regions and dark regions has been shown to have a serious negative impact on the performance of face recognition systems. This paper proposes a solution to this problem based on self-quotient image (SQI) processing method. In this method, bright and dark areas are processed separately without changing the essential characteristics of the image of the face. The dark and light areas are processed separately by SQI. Experimental results indicate that this Single-Light-Region and Single-Dark-Region SQI method removes the adverse effect of multi-bright and multi-dark areas better than competing methods.
Markov semigroups, monoids and groups
Authors: Cain Alan J. , Maltcev Victor
Published: June 2014

A group is Markov if it admits a prefix-closed regular language of unique representatives with respect to some generating set, and strongly Markov if it admits such a language of unique minimal-length representatives over every generating set. This paper considers the natural generalizations of these concepts to semigroups and monoids. Two distinct potential generalizations to monoids are shown to be equivalent. Various interesting examples are presented, including an example of a non-Markov monoid that nevertheless admits a regular language of unique representatives over any generating set. It is shown that all finitely generated commutative semigroups are strongly Markov, but that finitely generated subsemigroups of virtually abelian or polycyclic groups need not be. Potential connections with word-hyperbolic semigroups are investigated. A study is made of the interaction of the classes of Markov and strongly Markov semigroups with direct products, free products, and finite-index subsemigroups and extensions. Several questions are posed.
Resonance-like QGP signals displayed in general charge balance functions
Authors: Pan Ying-Hua , Zhang Wei-Ning
Published: June 2014

Experiment and lattice simulation show that the quark–gluon plasma (QGP) system displays strong interaction between constituents at temperature a few times the critical temperature Tc. This QGP picture can be explained by assuming that the QGP matter above Tc is rich in different kinds of bound states, namely resonance-like QGP (RQGP). The chemical composition of the QGP system produced in ultra-relativistic heavy-ion collisions can be investigated through a general charge balance function which describes two-wave quark production during expansion afterward. In this paper, we investigate the signals of this RQGP through general charge balance functions. We find that the quasiparticles in QGP contribute a little to the balance functions because of their heavy masses. The balance functions reduce to the situation discussed before where only one-wave charge production is involved if only the quasiparticles in QGP are considered. However, the baryonic bound states in QGP have a significant effect on the balance function [Formula: see text], causing a dip in the [Formula: see text] balance function at small Δy. The existence of the binary and baryonic bound states amplify the negative dip of the balance function BpK-(Δy) at Δy ∽ 1.
UTILITY MAXIMIZATION IN A BINOMIAL MODEL WITH TRANSACTION COSTS: A DUALITY APPROACH BASED ON THE SHADOW PRICE PROCESS
Authors: BAYER CHRISTIAN , VELIYEV BEZIRGEN
Published: June 2014

We consider the problem of optimizing the expected logarithmic utility of the value of a portfolio in a binomial model with proportional transaction costs with a long time horizon. By duality methods, we can find expressions for the boundaries of the no-trade-region and the asymptotic optimal growth rate, which can be made explicit for small transaction costs (in the sense of an asymptotic expansion). Here we find that, contrary to the classical results in continuous time, see Janeček and Shreve (2004), Finance and Stochastics8, 181–206, the size of the no-trade-region as well as the asymptotic growth rate depend analytically on the level λ of transaction costs, implying a linear first-order effect of perturbations of (small) transaction costs, in contrast to effects of orders λ1/3 and λ2/3, respectively, as in continuous time models. Following the recent study by Gerhold et al. (2013), Finance and Stochastics17, 325–354, we obtain the asymptotic expansion by an almost explicit construction of the shadow price process.
CONVERGENCE OF EUROPEAN LOOKBACK OPTIONS WITH FLOATING STRIKE IN THE BINOMIAL MODEL
Authors: HEUWELYCKX FABIEN
Published: June 2014

In this paper, we study the convergence of a European lookback option with floating strike evaluated with the binomial model of Cox–Ross–Rubinstein to its evaluation with the Black–Scholes model. We do the same for its delta. We confirm that these convergences are of order [Formula: see text]. For this, we use the binomial model of Cheuk–Vorst which allows us to write the price of the option using a double sum. Based on an improvement of a lemma of Lin–Palmer, we are able to give the precise value of the term in [Formula: see text] in the expansion of the error; we also obtain the value of the term in 1/n if the risk free interest rate is nonzero. This modelization will also allow us to determine the first term in the expansion of the delta.
A FINITE-HORIZON OPTIMAL INVESTMENT AND CONSUMPTION PROBLEM USING REGIME-SWITCHING MODELS
Authors: LIU R. H.
Published: June 2014

This paper is concerned with a finite-horizon optimal investment and consumption problem in continuous-time regime-switching models. The market consists of one bond and n ≥ 1 correlated stocks. An investor distributes his/her wealth among these assets and consumes at a non-negative rate. The market parameters (the interest rate, the appreciation rates and the volatilities of the stocks) and the utility functions are assumed to depend on a continuous-time Markov chain with a finite number of states. The objective is to maximize the expected discounted total utility of consumption and the expected discounted utility from terminal wealth. We solve the optimization problem by applying the stochastic control methods to regime-switching models. Under suitable conditions, we prove a verification theorem. We then apply the verification theorem to a power utility function and obtain, up to the solution of a system of coupled ordinary differential equations, an explicit solution of the value function and the optimal investment and consumption policies. We illustrate the impact of regime-switching on the optimal investment and consumption policies with numerical results and compare the results with the classical Merton problem that has only a single regime.
PREPAYMENT OPTION OF A PERPETUAL CORPORATE LOAN: THE IMPACT OF THE FUNDING COSTS
Authors: PAPIN TIMOTHEE , TURINICI GABRIEL
Published: June 2014

We investigate in this paper a perpetual prepayment option related to a corporate loan. The short interest rate and default intensity of the firm are supposed to follow Cox–Ingersoll–Ross (CIR) processes. A liquidity term that represents the funding costs of the bank is introduced and modeled as a continuous time discrete state Markov chain. The prepayment option needs specific attention as the payoff itself is a derivative product and thus an implicit function of the parameters of the problem and of the dynamics. We prove verification results that allows to certify the geometry of the exercise region and compute the price of the option. We show moreover that the price is the solution of a constrained minimization problem and propose a numerical algorithm building on this result. The algorithm is implemented in a two-dimensional code and several examples are considered. It is found that the impact of the prepayment option on the loan value is not to be neglected and should be used to assess the risks related to client prepayment. Moreover, the Markov chain liquidity model is seen to describe more accurately clients' prepayment behavior than a model with constant liquidity.
Performance comparison of Poisson–Boltzmann equation solvers DelPhi and PBSA in calculation of electrostatic solvation energies
Authors: Li Anbang
Published: June 2014

Many Poisson–Boltzmann equation (PBE) solvers have been developed to calculate electrostatic energy of biomolecules, and each PBE solver has its advantages. In this study two PBE solvers — DelPhi and PBSA module in AMBER — are compared in terms of calculation results, convergence and program-running time by calculating the electrostatic solvation energy for a test set composed of 4 Kirkwood models and another test set of 25 protein structures. The protein structures were pretreated by AMBER and AMBER99SB force field parameters were used in all calculations. It is found that (i) At fine grids, both PBE solvers can produce accurate results on test set 1 and consistent results with each other on test set 2, with differences between each other varying from several to ~ 10 kcal/mol. (ii) Under convergence criterion "absolute value of relative error is less than or equal to 2% (|RE| ≤ 2%)", both PBE solvers need very fine grids to produce convergent results on small and complex Kirkwood models, while grid spacings of ≤ 0.5 Å–0.6 Å are well enough for them to achieve good convergent results on various molecular structures. We recommend users to adopt such grid spacing in using of these PBE solvers so as to get good enough convergent results. (iii) In terms of time consumption, DelPhi appears to be more time-saving than PBSA. In summary, according to our comparison, DelPhi and PBSA are paralleled good PBE solvers. The convergence of PBSA is a little better than DelPhi, while DelPhi exceeds PBSA in running speed.
Fréchet geometry via projective limits
Authors: Dodson C. T. J.
Published: June 2014

Fréchet spaces of sections arise naturally as configurations of a physical field. Some recent work in Fréchet geometry is briefly reviewed and some suggestions for future work are offered. An earlier result on the structure of second tangent bundles in the finite-dimensional case was extended to infinite-dimensional Banach manifolds and Fréchet manifolds that could be represented as projective limits of Banach manifolds. This led to further results concerning the characterization of second tangent bundles and differential equations in the more general Fréchet structure needed for applications.